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Ensembl Genome Browser Workshop – Graphic Era Hill University (GEHU)

Course Details

Lead Trainer
Jorge Batista da Rocha
Associate Trainer(s)
Event Date
2024-11-25
Location
  Dehradun, India
Description
Work with the Ensembl Outreach team to get to grips with the Ensembl browser, accessing gene, regulation and comparative genomics data.
Survey
 Ensembl Genome Browser Workshop – Graphic Era Hill University (GEHU) Feedback Survey

Demos and exercises

Species and genome assemblies

Demo: Introduction to Ensembl

Ensembl

Homepage

The front page of Ensembl is found at ensembl.org. It contains lots of information and links to help you navigate Ensembl:

On the right-hand panel you can see the current release number and what has come out in this release. To access old releases, scroll to the bottom of the page and click on View in archive site in the right-hand corner.

Click on the links to go to the archives. Alternatively, you can jump quickly to the correct release by adding e plus the release number in the URL. For example e98.ensembl.org jumps to Ensembl release 98.  
 
 

Available species

Scroll back up to the top of the homepage. You can view all available species by clicking the View full list of all species link underneath the coloured search block.

You can search for your species of interest (either the common or scientific name) using the search bar at the top right-hand corner of the table. Click on the common name of your species of interest to go to the species information page. We’ll click on Human.

 
 
 

Species information

Here you can see links to example features and to download flatfiles. To find out more about the genome assembly and genebuild, click on More information and statistics under the Genome assembly section.

Here you’ll find a detailed description of how to the genome was produced and links to the original source. You will also see details of how the genes were annotated.

The current genome assembly for human is GRCh38. If you want to see the previous assembly, GRCh37, visit our dedicated site grch37.ensembl.org.

 
 
 

Ensembl Genomes

Homepage

Let’s take a look at the Ensembl Genomes homepage at ensemblgenomes.org.

Click on the different taxa to see their homepages. Each one has a different colour-coding, but they are all structured in a similar format to the Ensembl main site.

You can navigate most of the taxa in the same way as you would with Ensembl.  
 
 

Ensembl Bacteria

Ensembl Bacteria has a large number of genomes and has a slightly different method to the other Ensembl sites. Let’s look at it in more detail.

There’s no drop-down species list for bacteria as it would be hard to navigate with the number of species. You can click the View full list of all Ensembl Bacteria species link underneath the coloured search block. Search for your species of interest using the filter in the top right-hand corner of the table.

Alternatively, you can find a species by typing the species name into the Search for a genome search box at the top of the page. A drop-down list will appear with any species matching the name you entered.

For example, to find a sub-strain of Clostridioides difficile start typing in the species name. Due to the auto-complete, you’ll see useful results as soon as you get to Clostridio.

The drop down contains various strains of C. difficile. Let’s choose C. difficile 630. This will take us to another species information page, where we can explore various features.

Unlike the Homo sapiens species information page, there is no prose description of the genome or gene annotation, as these pages were generated automatically.  
 
 

Ensembl Rapid Release

Our newest genomes, such as those coming from the Darwin Tree of Life, are available rapid.ensembl.org with limited annotation.

Panda species

Go to Ensembl and find the following information:

  1. What is the name of the genome assembly for Panda?

  2. How long is the Panda genome (in bp)? How many coding genes have been annotated?

  1. Select Giant panda from the drop down species list, or click on View full list of all Ensembl species, then choose Giant panda from the list.
    The assembly is ASM200744v2 or GCA_002007445.2.

  2. Click on More information and statistics. Statistics are shown in the tables on the left.
    The length of the genome is 2,444,060,653 bp.
    There are 20,857 coding genes.

Available zebrafish assemblies

What previous assemblies are available for zebrafish?

Click on Zebrafish on the front page of Ensembl to go to the species homepage. Under Other assemblies three previous assembly names and the releases you can find them in are listed.
Assembly GRCz10 is available in the archived release 80, Zv9 in 77 and Zv8 in 54.

Solanum genus

Go to Ensembl Plants and answer the following questions:

  1. How many genomes of the genus Solanum are there in Ensembl Plants?

  2. When was the current Solanum lycopersicum genome assembly last revised?

  1. On the homepage, click on View full list of all Ensembl Plants species underneath the coloured search block. Type Solanum into the filter box in the top left-hand corner of the table.

    There are three Solanum genomes: Solanum lycopersicum (tomato), and Solanum tuberosum RH89-039-16 and Solanum tuberosum (both potato).

  2. Click on S. lycopersicum, then on More information and statistics.

    The genome was revised in April 2018.

Mosquito species

  1. Go to Ensembl Metazoa. How many genomes relating to the genus Anopheles are there in Ensembl Metazoa?

  2. When was the current Anopheles gambiae genome assembly last revised?

  1. Go to metazoa.ensembl.org. Open the drop-down list or click on View full list of all Ensembl Metazoa species. In a latin binomial species name, the first word represents the genus. Type Anopheles into the filter box in the top left to find all genomes with this word in the binomial.

    There are 22 Anopheles genomes (some species are represented by more than one genome).

  2. Click on Anopheles gambiae (African malaria mosquito, PEST), and then on More information and statistics.

    The assembly hosted is AgamP4 (INSDC Assembly GCA_000005575.1) which was revised in Feb 2006.

Finding a genome in Ensembl Bacteria

Mycobacterium tuberculosis H37Ra str. ATCC25177 is a clinical strain.

Go to Ensembl Bacteria and find the species M. tuberculosis H37Ra str. ATCC25177. How many coding genes does it have?

In the Ensesmbl Bacteria homepage, start to type H37Ra into the Search for a genome search box (you can find this in the coloured block at the top of the homepage). It will auto-complete, allowing you to select M. tuberculosis H37Ra str. ATCC25177 from the drop-down list. Click on More information and statistics.

M. tuberculosis H37Ra str. ATCC25177 has 4,080 coding and 47 non-coding genes.

Exploring genomic regions

Start at the Ensembl front page, ensembl.org. You can search for a region by typing it into a search box, but you have to specify the species.

To bypass the text search, you need to input your region coordinates in the correct format, which is chromosome, colon, start coordinate, dash, end coordinate, with no spaces for example: human 4:122868000-122946000. Type (or copy and paste) these coordinates into either search box.

or

Press Enter or click Go to jump directly to the Region in detail Page.

Click on the button to view page-specific help. The help pages provide text, labelled images and, in some cases, help videos to describe what you can see on the page and how to interact with it.

The Region in detail page is made up of three images, let’s look at each one in detail.

The first image shows the chromosome:

The region we’re looking at is highlighted on the chromosome. You can jump to a different region by dragging out a box in this image. Drag out a box on the chromosome, a pop-up menu will appear.

If you wanted to move to the region, you could click on Jump to region (### bp). If you wanted to highlight it, click on Mark region (###bp). For now, we’ll close the pop-up by clicking on the X on the corner.

The second image shows a 1Mb region around our selected region. This is always 1Mb in human, but the fixed size of this view varies between species. This view allows you to scroll back and forth along the chromosome.

You can also drag out and jump to or mark a region.

Click on the X to close the pop-up menu.

Click on the Drag/Select button to change the action of your mouse click. Now you can scroll along the chromosome by clicking and dragging within the image. As you do this you’ll see the image below grey out and two blue buttons appear. Clicking on Update this image would jump the lower image to the region central to the scrollable image. We want to go back to where we started, so we’ll click on Reset scrollable image.

The third image is a detailed, configurable view of the region.

Here you can see various tracks, which is what we call a data type that you can plot against the genome. Some tracks, such as the transcripts, can be on the forward or reverse strand. Forward stranded features are shown above the blue contig track that runs across the middle of the image, with reverse stranded features below the contig. Other tracks, such as variants, regulatory features or conserved regions, refer to both strands of the genome, and these are shown by default at the very top or very bottom of the view.

You can use click and drag to either navigate around the region or highlight regions of interest, Click on the Drag/Select option at the top or bottom right to switch mouse action. On Drag, you can click and drag left or right to move along the genome, the page will reload when you drop the mouse button. On Select you can drag out a box to highlight or zoom in on a region of interest.

With the tool set to Select, drag out a box around an exon and choose Mark region.

The highlight will remain in place if you zoom in and out or move around the region. This allows you to keep track of regions or features of interest.

We can edit what we see on this page by clicking on the blue Configure this page menu at the left.

This will open a menu that allows you to change the image.

There are thousands of possible tracks that you can add. When you launch the view, you will see all the tracks that are currently turned on with their names on the left and an info icon on the right, which you can click on to expand the description of the track. Turn them on or off, or change the track style by clicking on the box next to the name. More details about the different track styles are in this FAQ: http://www.ensembl.org/Help/Faq?id=335.

You can find more tracks to add by either exploring the categories on the left, or using the Find a track option at the top left. Type in a word or phrase to find tracks with it in the track name or description.

Let’s add some tracks to this image. Add:

  • Proteins (mammal) from UniProt – Labels
  • 1000 Genomes - All - short variants (SNPs and indels) – Normal

Now click on the tick in the top left hand to save and close the menu. Alternatively, click anywhere outside of the menu. We can now see the tracks in the image. The proteins track is stranded, so you will see two tracks, one above and one below the contig, representing the proteins mapped to the forward and reverse strands respectively. The variants track is not stranded, so is found near the bottom of the image.

If the track is not giving you can information you need, you can easily change the way the tracks appear by hovering over the track name then the cog wheel to open a menu. To make it easier to compare information between tracks, such as spotting overlaps, you can move tracks around by clicking and dragging on the bar to the left of the track name.

Now that you’ve got the view how you want it, you might like to show something you’ve found to a colleague or collaborator. Click on the Share this page button to generate a link. Email the link to someone else, so that they can see the same view as you, including all the tracks you’ve added. These links contain the Ensembl release number, so if a new release or even assembly comes out, your link will just take you to the archive site for the release it was made on.

To return this to the default view, go to Configure this page and select Reset configuration at the bottom of the menu.

Exploring a genomic region in human

Go to Ensembl.

  1. Go to the region from 32,264,000 to 32,492,000 bp on human chromosome 13. On which cytogenetic band is this region located? How many contigs make up this portion of the assembly (contigs are contiguous stretches of DNA sequence that have been assembled solely based on direct sequencing information)?

  2. Zoom in on the BRCA2 gene.

  3. Configure this page to turn on the LTR (repeat) track in this view. What tool was used to annotate the LTRs according to the track information? How many LTRs can you see within the BRCA2 gene? Do any overlap exons?

  4. Create a Share link for this display. Email it to your neighbour. Open the link they sent you and compare. If there are differences, can you work out why?

  5. Export the genomic sequence of the region you are looking at in FASTA format.

  6. Turn off all tracks you added to the Region in detail page.

  1. Go to the Ensembl homepage, select Human from the Species drop-down list and type 13:32264000-32492000 in the text box (alternatively leave the Search drop-down list as it is and type 13:32264000-324920000 in the text box). Click Go.

    This genomic region is located on cytogenetic band q13.1. It is made up of three contigs, indicated by the alternating light and dark blue coloured bars in the Contigs track.

  2. Draw with your mouse a box encompassing the BRCA2 transcripts. Click on Jump to region in the pop-up menu.

  3. Click Configure this page in the side menu (or on the cog wheel icon in the top left hand side of the bottom image). Go into Repeats in the left-hand menu then select LTR. Click on the (i) button to find out more information.

    Repeat Masker was used to annotate LTRs onto the genome.
    Save and close the new configuration by clicking on ✓ (or anywhere outside the pop-up window). There are ten LTRs overlapping BRCA2, none of them overlap exons.

  4. Click Share this page in the side menu. Copy the URL. Get your neighbour’s email address and compose an email to them, paste the link in and send the message. When you receive the link from them, open the email and click on your link. You should be able to view the page with the new configuration and data tracks they have added to in the Location tab. You might see differences where they specified a slightly different region to you, or where they have added different tracks.

    Here is the Share link from the video answer: https://may2021.archive.ensembl.org/Homo_sapiens/Share/71a173bba78f0dbe03e48d3240424943?redirect=no;mobileredirect=no

  5. Click Export data in the side menu. Leave the default parameters as they are (FASTA sequence should already be selected). Click Next>. Click on Text. Note that the sequence has a header that provides information about the genome assembly (GRCh38), the chromosome, the start and end coordinates and the strand. For example:
    >13_dna:chromosome_chromosome:GRCh38:13:32311910:32405865:1

  6. Click Configure this page in the side menu. Click Reset configuration. Click ✓.

Exploring a genomic region in mouse

Go to the Ensembl homepage.

  1. Go to the region from 150,320,000 to 150,540,000 bp on mouse chromosome 5. How many contigs make up this portion of the assembly (contigs are contiguous stretches of DNA sequence that have been assembled solely based on direct sequencing information)?

  2. Zoom in on the Brca2 gene.

  3. Configure this page to turn on the LTR (repeat) track in this view. What tool was used to annotate the LTRs according to the track information? How many LTRs can you see within the Brca2 gene? Do any overlap exons?

  4. Create a Share link for this display. Email it to your neighbour. Open the link they sent you and compare. If there are differences, can you work out why?

  5. Export the genomic sequence of the region you are looking at in FASTA format.

  6. Turn off all tracks you added to the Region in detail page.

  1. Select Mouse from the Species search list and type 5:150320000-150540000 in the text box (or alternatively leave the Search drop-down list like it is and type mouse 5:150320000-150540000 in the text box). Click Go.

    It is made up of five contigs, indicated by the alternating light and dark blue coloured bars in the Contigs track. Note the tiny contig, AEKQ02165236.1, which splits AC084217.7 in two.

  2. Draw with your mouse a box encompassing the Brca2 transcripts. Click on Jump to region in the pop-up menu.

  3. Click Configure this page in the side menu (or on the cog wheel icon in the top left hand side of the bottom image). Go to Repeats in the left-hand menu then select LTRs (Repeats (Mouse)). Click on the (i) button to find out more information.

    Repeat Masker was used to annotate LTRs onto the genome.

    Save and close the new configuration by clicking on ✓ (or anywhere outside the pop-up window).

    There are seven LTRs overlapping Brca2, none of them overlap exons.

  4. Click Share this page in the side menu. Select the link and copy. Get your neighbour’s email address and compose an email to them, paste the link in and send the message. When you receive the link from them, open the email and click on your link. You should be able to view the page with the new configuration and data tracks they have added to in the Location tab. You might see differences where they specified a slightly different region to you, or where they have added different tracks.

  5. Click Export data in the side menu. Leave the default parameters as they are. Click Next>. Click on Text.

  6. Click Configure this page in the side menu. Click Reset configuration. Click ✓.

Exploring a genomic region in Oryza sativa Japonica (rice)

Go to the Ensembl Plants homepage and do the following:

  1. Go to the region between 405000 and 453000 on chromosome 1 in Oryza sativa Japonica.

  2. Turn on the AGILENT:G2519F-015241 microarray track. Are there any oligo probes that map to this region?

  3. Highlight the region around any reverse strand probes you can see. Do they map to any Ensembl transcripts?

  1. Go to the Ensembl Plants homepage. Select Oryza sativa Japonica from the Species drop-down list and type 1:405000-453000. Click Go.

  2. Click on Configure this page to open the menu. You can find the AGILENT:G2519F-015241 track under Oligo probes in the left-hand menu, or by using the Find a track box at the top right. Turn on the track as Normal then save and close the menu. As the AGILENT:G2519F-015241 track is stranded, it appears at the top and bottom of the view.

    There are 5 probes mapped to this region on the positive strand and one probe on the reverse strand.

  3. Drag a box around the reverse strand probe then click on Mark region to highlight.

    The highlighted region maps to two transcripts: Os01t0107900-02 and Os01t0107900-01

Exploring a region in Coprinopsis cinerea okayama

Go to Ensembl Fungi. Let’s try to find some information about the region from 1,400,000 to 1,425,000 in chromosome 7 in Coprinopsis cinerea okayama:

  1. How many complete genes are found in this region? How many on the forward and how many on the reverse strand?

  2. Zoom in on the largest gene EFI27358. How many exons does this gene have?

  3. Export the genomic sequence in FASTA format for this region.

  1. In the Ensembl Fungi homepage, select Coprinopsis cinerea okayama from the Species search drop-down. Enter 7:1400000-1425000 in the Search bar and click Go. This will send you to the Location tab. Your region of interest is indicated by a red rectangle in the 50kb view. Look at the Genes track: each block represents a different gene. Count the number of complete genes within the rectangle.

    There are 7 complete genes in the region.

  2. Look at the Region in detail view (the most detailed view at the bottom of the page). You can zoom into a region by clicking and dragging your mouse (you can change your mouse action in the top right-hand corner of the view under **Drag/Select) and selecting Jump to region in the pop-up menu. Count the number of blocks you can see for EFI27358.

    The EFI27358 gene has 23 exons.

    Click on the transcript ID CZT99117 in the transcript table.

    It has 4 exons.

  3. We want to export the genomic sequence for our original region (not just the EFI27358 gene). You can reset the view by entering 7:1400000-1425000 in the Location bar above the Region in detail view or hitting the Back button on your internet browser. Click on Export data in the left-hand panel. In the pop-up menu, select FASTA from the drop-down and click Next >. You can export the sequence as is (text) or as a compressed file (.gz).

    If you choose to download the sequence as text, your browser might open the FASTA file in a new tab. In this case, just right-click on any white space and select Save As… from the menu.

Exploring a genomic region in Salmonella enterica

Go to Ensembl Bacteria and do the following:

  1. Search for the Salmonella enterica subsp. enterica serovar Typhi str. Ty2 (GCA_000007545) (Hint: type Ty into the Search for a genome box).

  2. Go to the region Chromosome:2000605-2009742.

  3. How many genes are annotated in this region? How many are on the forward strand? How many are on the reverse strand?

  1. Go to the Ensembl Bacteria homepage. Type Ty2 into the Search for a genome box. Click on the auto-completed genome name to navigate to the species information page.

  2. Type Chromosome:2000605-2009742 into the search box. Click Go.

  3. There are 8 genes annotated in this region, all on the reverse strand.

Genes and transcripts

You can find out lots of information about Ensembl genes and transcripts using the browser. If you’re already looking at a region view, you can click on any transcript and a pop-up menu will appear, allowing you to jump directly to that gene or transcript.

Alternatively, you can find a gene by searching for it. You can search for gene names or identifiers, and also phenotypes or functions that might be associated with the genes.

We’re going to look at the human UQCRQ gene. From ensembl.org, type UQCRQ into the search bar and click the Go button. You will get a list of hits with the human gene at the top.

Where you search for something without specifying the species, or where the ID is not restricted to a single species, the most popular species will appear first, in this case, human, mouse and zebrafish appear first. You can restrict your query to species or features of interest using the options on the left.

The gene tab

Click on the gene name or Ensembl ID. The Gene tab should open:

This page summarises the gene, including its location, name and equivalents in other databases. At the bottom of the page, a graphic shows a region view with the transcripts. We can see exons shown as blocks with introns as lines linking them together. Coding exons are filled, whereas non-coding exons are empty. We can also see the overlapping and neighbouring genes and other genomic features.

There are different tabs for different types of features, such as genes, transcripts or variants. These appear side-by-side across the blue bar, allowing you to jump back and forth between features of interest. Each tab has its own navigation column down the left hand side of the page, listing all the things you can see for this feature.

Let’s walk through this menu for the gene tab. How can we view the genomic sequence? Click Sequence at the left of the page.

The sequence is shown in FASTA format. The FASTA header contains the genome assembly, chromosome, coordinates and strand (1 or -1) – this gene is on the positive strand.

Exons are highlighted within the genomic sequence, both exons of our gene of interest and any neighbouring or overlapping gene. By default, 600 bases are shown up and downstream of the gene. We can make changes to how this sequence appears with the blue Configure this page button found at the left. This allows us to change the flanking regions, add variants, add line numbering and more. Click on it now.

Once you have selected changes (in this example, Show variants, 1000 Genomes variants and Line numbering) click at the top right.

You can download this sequence by clicking in the Download sequence button above the sequence:

This will open a dialogue box that allows you to pick between plain FASTA sequence, or sequence in RTF, which includes all the coloured annotations and can be opened in a word processor. If you want run a sequence analysis tool, download as FASTA sequence, whereas if you want to analyse the sequence visually, RTF is best for this. This button is available for all sequence views.

To find out what the protein does, have a look at GO terms from the Gene Ontology consortium. There are three pages of GO terms, representing the three divisions in GO: Biological process (what the protein does), Cellular component (where the protein is) and Molecular function (how it does it). Click on GO: Biological process to see an example of the GO pages.

Here you can see the functions that have been associated with the gene. There are three-letter codes that indicate how the association was made, as well as links to the specific transcript they are linked to.

We also have links out to other databases which have information about our genes and may focus on other topics that we don’t cover, like Gene Expression Atlas or OMIM. Go up the left-hand menu to External references:

Demo: The transcript tab

We’re now going to explore the different transcripts of UQCRQ. Click on Show transcript table at the top.

Here we can see a list of all the transcripts of UQCRQ with their identifiers, lengths, biotypes and flags to help you decide which ones to look at.

If we were to only choose one transcript to analyse, we would choose UQCRQ-203 because it is the MANE Select and Ensembl Canonical. This means it is both 100% identical to the RefSeq transcript NM_014402.5 and both Ensembl and NCBI agree that it is the most biologically important transcript.

Click on the ID, ENST00000378670.8.

You are now in the Transcript tab for UQCRQ-203. We can still see the gene tab so we can easily jump back. The left hand navigation column provides several options for the transcript UQCRQ-203 - many of these are similar to the options you see in the gene tab, but not all of them. If you can’t find the thing you’re looking for, often the solution is to switch tabs.

Click on the Exons link. This page is useful for designing RT-PCR primers because you can see the sequences of the different exons and their lengths.

You may want to change the display (for example, to show more flanking sequence, or to show full introns). In order to do so click on Configure this page and change the display options accordingly.

Now click on the cDNA link to see the spliced transcript sequence with the amino acid sequence. This page is useful for mapping between the RNA and protein sequences, particularly genetic variants.

UnTranslated Regions (UTRs) are highlighted in dark yellow, codons are highlighted in light yellow, and exon sequence is shown in black or blue letters to show exon divides. Sequence variants are represented by highlighted nucleotides and clickable IUPAC codes are above the sequence.

Next, follow the General identifiers link at the left. Just like the External References page in the gene tab, this page shows links out to other databases such as RefSeq, UniProtKB, PDBe and others, this time linked to the transcript or protein product, rather than the gene.

If you’re interested in protein domains, you could click on Protein summary to view domains from Pfam, PROSITE, Superfamily, InterPro, and more. These are all plotted against the transcript sequence, with the exons shown in alternating shades of purple at the top of the page. Alternatively, you can go to Domains & features to see a table of the same information.

You can also see the structure of the protein from the PDB by clicking on PDB 3D Protein model.

This uses LiteMol to show a 3D protein. You can use all the normal controls that you would use with LiteMol, plus plot Ensembl features like Exons and variants onto the structure using the options on the right. We allow you to see the top ten PDB models for this protein, based on coverage and quality scores, you can choose which at the top of the viewer.

Exploring the MYH9 gene in human

  1. In Ensembl, find the human MYH9 (myosin, heavy chain 9, non-muscle) gene and open the Gene tab.
    • On which chromosome and which strand of the genome is this gene located?
    • How many transcripts (splice variants) are there and how many are protein coding?
    • What is the longest protein-coding transcript, and how long is the protein it encodes?
    • Which transcript would you take forward for further study?
  2. Click on Phenotypes at the left side of the page. Are there any diseases associated with this gene, according to Mendelian Inheritance in Man (MIM)?

  3. What are some functions of MYH9 according to the Gene Ontology (GO) consortium? Have a look at the GO: Biological process pages for this gene.

  4. In the transcript table, click on the transcript ID for MYH9-201, and go to the Transcript tab.
    • How many exons does it have?
    • Are any of the exons completely or partially untranslated?
    • Is there an associated sequence in UniProtKB/Swiss-Prot? Have a look at the General identifiers for this transcript.
  5. Are there microarray (oligo) probes that can be used to monitor ENST00000216181 expression?
  1. Select Human from the Species drop-down list and type MYH9. Click Go. Click on MYH9 (Human Gene) in the search results which will send you to the Gene tab.
    • The gene is located on chromosome 22 on the reverse strand.
    • Ensembl has 23 transcripts annotated for this gene, of which 6 are protein-coding.
    • The longest protein-coding transcript is MYH9-215 and it codes for a protein that is 1,981 amino acids long.
    • MYH9-201 is the transcript I would take forward for further study, as it is the MANE Select transcript (for a description, mouse-over the MANE Select flag in the transcript table).
  2. Click on Phenotypes in the left-hand panel to see the associated phenotypes. There is a large table of phenotypes. To see only the ones from MIM, type MIM into the filter box at the top right-hand corner of the table.

    These are some of the phenotypes associated with MYH9 according to MIM: Deafness, Autosomal dominant 17 and Macrothrombocytopenia and granulocyte inclusions with or without nephritis or sensorineural hearing loss. You can click on the records for more information.

  3. The Gene Ontology project maps terms to a protein in three classes: biological process, cellular component, and molecular function. Click on GO: Biological process on the left-hand panel. Angiogenesis, cell adhesion, and protein transport are some of the roles associated with MYH9. All GO terms are associated with a single transcript: ENST00000216181.

  4. Click on ENST00000216181.11 in the transcript table. You should now be on the Transcript tab.
    • It has 41 exons, shown in the Transcript summary.

    Click on the Exons link in the left-hand panel.

    • Exon 1 is completely untranslated, and exons 2 and 41 are partially untranslated (UTR sequence is shown in orange). You can also see this in the cDNA view if you click on the cDNA link in the left side menu.

    Click on General identifiers in the left-hand panel.

    • P35579.247 from UniProt/Swiss-Prot matches the translation of the Ensembl transcript. Click on P35579.247 to go to UniProtKB, or click align for the alignment.
  5. Click on Oligo probes in the left-hand panel.

    Probesets from Affymetrix, Agilent, Codelink, Illumina, and Phalanx OneArray match to this transcript sequence. Expression analysis with any of these probesets would reveal information about the transcript. Hint: this information can sometimes be found in the [ArrayExpress Atlas] (https://www.ebi.ac.uk/biostudies/arrayexpress).

Finding a gene associated with a phenotype

Phenylketonuria is a genetic disorder caused by an inability to metabolise phenylalanine in any body tissue. This results in an accumulation of phenylalanine causing seizures and intellectual disability.

(a) Search for phenylketonuria from the Ensembl homepage and narrow down your search to only genes. What gene is associated with this disorder?

(b) How many protein coding transcripts does this gene have? View all of these in the transcript comparison view.

(c) What is the MIM gene identifier for this gene?

(d) Go to the MANE Select transcript and look at its 3D structure. In the model 2pah, how many protein molecules can you see?

(a) Start at the Ensembl homepage (http://www.ensembl.org).

Type phenylketonuria into the search box then click Go. Choose Gene from the left hand menu.

The gene associated with this disorder is PAH, phenylalanine hydroxylase, ENSG00000171759.

(b) If the transcript table is hidden, click on Show transcript table to see it.

There are six protein coding transcripts.

Click on Transcript comparison in the left hand menu. Click on Select transcripts. Either select all the transcripts labelled protein coding one-by-one, or click on the drop down and select Protein coding. Close the menu.

(c) Click on External references.

The MIM gene ID is 612349.

(d) Open the transcript table and click on the ID for the MANE Select: ENST00000553106.6. Go to PDB 3D protein model in the left-hand menu.

The model 2pah is shown by default. It has two protein molecules in it. You may need to rotate the model to see this clearly.

Exploring the Dpp6 gene in mouse

Genetic variation in the dipeptidylpeptidase 6 Gene (DPP6) in humans has previously been strongly associated with amyotrophic lateral sclerosis (ALS), a lethal disorder caused by progressive degeneration of motor neurons in the brain.

  1. Go to the Ensembl homepage, search for the Dpp6 gene in mouse and click on the transcript ID ENSMUST00000071500 to open the transcript tab. How many exons make up this transcript?

  2. Click on Exons to display the exon sequences of the transcript. Which exon contains the translation start? What is the exon ID of the largest exon? What is the start and end phase of exon 2?

  3. Go to the Protein summary. How many protein domains or features fall within the second exon? What is the Pfam protein domain at the C-terminus of the protein and how many exons does it fall into? Which amino acid positions does the domain above cover?

  4. Go to Domains and features. Which domains are associated with Pfam? How many genes in the mouse genome have the IPR002469 domain? What chromosomes are these genes found on?

  1. Select Mouse from the Species search drop-down and type Dpp6 and click Go. Click on Dpp6-201 (Mouse Transcript, Strain: reference (CL57BL6)) in the results.

    ENSMUST00000071500.13 consists of 26 exons.

  2. Click on Exons in the left-hand panel. The translation start is found in the first exon (ENSMUSE00000725552), shown in dark blue text.

    The largest exon is the final exon (856 bp), which has the exon ID ENSMUSE00000773588. Exon 2 has a start and end phase of 0 and 1 respectively, which means that the codon at the start of the exon starts at the first nucleotide and the codon at the end of the exon ends at nucleotide 2. Notice that the end phase of each exon is the same as the start phase of the next exon.

  3. Click on Protein summary in the menu on the left hand side of the page. Alternating exons are shown on the protein as different shades of purple.

    There are two predicted protein domains that fall within the second exon: a transmembrane helix and low complexity peptide sequence (Seg). You can click on the track names to find a description.

    Click on a domain or feature to view further information.

    The C-terminal Pfam domain is Peptidase_S9 (PF00326), which spans or partially spans seven exons, covering amino acid positions 582-787.

  4. Click on Domains & features.

    Looking at the domains table you should notice that there are two domains associated with Pfam: PF00326 and PF00930.

    Click on Display all genes with this domain next to IPR002469. This should now display the genes that have the IPR002469 domain located on the karyotype and as a table.

    6 genes have this domain and they are found on chromosomes 1, 2, 5, 9 and 17.

Exploring the CCD7 gene in Arabidopsis thaliana

  1. Find the Arabidopsis thaliana CCD7 gene on Ensembl Plants. On which chromosome and which strand of the genome is this gene located?

  2. Where in the cell is the CCD7 protein located?

  3. What is the source of the assigned gene name?

  4. How many transcripts does it have? How long is its longest transcript (in bp)? How long is the protein it encodes? How many exons does it have? Are any of the exons completely or partially untranslated?

  1. Go to the Ensembl Plants homepage (http://plants.ensembl.org/). Select A. thaliana from the species list and type CCD7 in the search box. Click Go and click on the gene ID AT2G44990. You can find the strand orientation and the location under Summary in the Gene tab.

    The A. thaliana CCD7 gene is located on chromosome 2 on the forward strand.

  2. Click on GO: Cellular component in the left-hand panel.

    The protein is located in the chloroplast and plastid.

  3. Click on Summary in the side menu.

    The gene name is assigned and imported from NCBI gene (formerly Entrezgene).

  4. Click on Show transcript table.

    There are 3 transcripts. The longest one is 2005 bp and the length of the encoded protein is 622 amino acids.

    Click on the transcript ID AT2G44990.3 in the transcript table. You can find the number of exons in under in the summary information at the top of the page.

    It has 6 exons.

    Click on Sequence: Exons in the left-hand panel.

    The first and last exons are partially untranslated (sequence shown in orange). This can also been seen from the fact that in the transcript diagrams on the Gene Summary and Transcript Summary pages the boxes representing the first and last exon are partially unfilled.

Exploring a bacterial gene in Clostridium sporogenes

Start in Ensembl Bacteria and select the Clostridium sporogenes (GCA_001444695) genome.

  1. What GO: biological process terms are associated with the PolC gene?

  2. Go to the transcript tab for the only transcript, OQP95999. How long is the transcript?

  3. What domains can be found in the protein product of this transcript? How many different domain prediction methods agree with each of these domains?

  1. From the Ensembl Bacteria homepage, select Clostridium sporogenes by beginning to write the species name and selecting the species from the auto-complete list. Type PolC and click on the gene ID VT92_0235670. Click on GO: biological process in the left-hand panel.

    There are two terms listed: GO:0006260, DNA replication and GO:0006261, DNA-templated DNA replication.

  2. Click on the transcript named OQP95999 or on the Transcript tab.

    OQP95999 is 4299 bp in length.

  3. Click on either Protein Summary or Domains & features in the left hand menu to see graphically or as a table respectively.

Exploring a gene in Escherichia coli

Start in Ensembl Bacteria and search for the Escherichia coli str. K-12 substr. MG1655 (GCA_000005845) genome.

  1. What GO: biological process terms are associated with the Era gene?

  2. How many different InterPro domains are found in the protein product of this gene?

  3. What is the associated UniProt ID of the transcript?

Enter part of the name into the genome search box (e.g. MG1655) and then select the correct genome to go to the species information page.

  1. Enter Era into the search box and hit Go. Click the link in the first hit to go to the era gene page. From here, click GO: Biological process in the left-hand menu.

    There are three GO IDs: GO:0000028, GO:0006468, GO:0042274 and GO:0046777.

  2. Click on the transcript ID AAC75619 in the transcript table on the Gene tab. In the Transcript tab, go to Domains & features in the left-hand panel. Count the number of unique InterPro IDs in the table.

    11 different InterPro domains are found in the protein product of Era.

  3. You can find the UniProt ID in the transcript table or under General identifiers in the left-hand panel.

    The UniProt ID is P60785.

Variation

In any of the sequence views shown in the Gene and Transcript tabs, you can view variants on the sequence. You can do this by clicking on Configure this page from any of these views.

Let’s take a look at the Gene sequence view for HBB in human. Search for HBB and go to the Sequence view.

If you can’t see variants marked on this view, click on Configure this page and select Show variants: Yes and show links. You may also wish to add a filter to the variants to allow them to load more quickly, we’ll add Filter variants by evidence status: 1000Genomes.

Find out more about a variant by clicking on it.

You can add variants to all other sequence views in the same way.

You can go to the Variation tab by clicking on the variant ID. For now, we’ll explore more ways of finding variants.

To view all the sequence variants in table form, click the Variant table link at the left of the gene tab.

You can filter the table to only show the variants you’re interested in. For example, click on Consequences: All, then select the variant consequences you’re interested in. For display purposes, the table above has already been filtered to only show missense variants.

You can also filter by the different pathogenicity scores and MAF, or click on Filter other columns for filtering by other columns such as Evidence or Class.

The table contains lots of information about the variants. You can click on the IDs here to go to the Variation tab too.

You can also see the phenotypes associated with a gene. Click on Phenotype in the left hand menu.

Open the transcript table and go to HBB-201 ENST00000335295, then click on Haplotypes in the left hand menu.

The Haplotypes view in the transcript tab shows you the actual protein and CDS sequences in 1000 Genomes individuals. This is possible because the 1000 Genomes study has phased genotypes, so we know which alleles occur on which of the chromosome pairs. The table lists all the versions of the protein that occur along with their frequencies, including the reference sequence and sequences with one or more alternative alleles.

Click on one of the haplotypes, we’ll go for 18K>*,​19del{130}, to find out more about it. Here you will see the frequency in the 1000 Genomes subpopulations, the sequence and the 1000 Genomes individuals where this protein is found.

Let’s have a look at variants in the Location tab. Click on the Location tab in the top bar.

Configure this page and open Variation from the left-hand menu.

There are various options for turning on variants. You can turn on variants by source, by frequency, presence of a phenotype or by individual genome they were isolated from. You can also turn on genotyping chips.

Let’s have a look at a specific variant. If we zoomed in we could see the variant rs334 in this region, however it’s easier to find if we put rs334 into the search box. Click through to open the Variation tab.

The icons show you what information is available for this variant. Click on Genes and regulation, or follow the link on the left.

This page illustrates the genes the variant falls within and the consequences on those genes, including pathogenicity predictors. It also shows data from GTEx on genes that have increased/decreased expression in individuals with this variant, in different tissues. Finally, regulatory features and motifs that the variant falls within are shown.

We can also see the variant in the protein structure by clicking on 3D Protein model.

This is a LiteMol viewer, where you can rotate and zoom in on the structure. The variant location is highlighted, so you can see where it lands within the structure.

Let’s look at population genetics. Click on Population genetics in the left-hand menu.

The population allele frequencies are shown by study, including 1000 Genomes and gnomAD. Where genotype frequencies are available, these are shown in the tables.

There are big differences in allele frequencies between populations. Let’s have a look at the phenotypes associated with this variant to see if they are known to be specific to certain human populations. Click on Phenotype Data in the left-hand menu.

This variant is associated with various phenotypes, including sickle cell and malaria resistance. These phenotype associations come from sources including the GWAS catalog, ClinVar, Orphanet and OMIM. Where available, there are links to the original paper that made the association, the allele that is associated with the phenotype and p-values and other statistics.

Human population genetics and phenotype data

The SNP rs1738074 in the 5’ UTR of the human TAGAP gene has been identified as a genetic risk factor for a few diseases. Use Ensembl to answer the following questions:

  1. In which transcripts is this SNP found?

  2. What is the least frequent genotype for this SNP in the Yoruba (YRI) population from the 1000 Genomes phase 3?

  3. What is the ancestral allele? Is it conserved in the 91 eutherian mammals EPO-Extended?

  4. With which diseases is this SNP associated? Are there any known risk (or associated) alleles?

  1. Please note there is more than one way to get this answer. Either go to the Variation table of the human TAGAP gene, and use the Consequence filter to only include 5’UTR variants, or search Ensembl for rs1738074 directly. Once you’re in the Variant tab, click on Genes and regulation in the menu.

    This SNP is found in four transcripts of TAGAP. It is also intronic to eleven non-coding transcripts of TAGAP-AS1 and one non-coding transcript of ENSG00000226032.

  2. Click on Population genetics in the left-hand panel, or click on Explore this variant in the left-hand panel and click the Population genetics icon.

    In Yoruba (YRI), the least frequent genotype is CC at the frequency of 5.6%.

  3. Click on Phylogenetic context in the left-hand panel.

    The ancestral allele is T and it’s inferred from the alignment in primates.

    Click on Select an alignment which will open a pop-up menu. Open Multiple alignments and select 91 eutherian mammals EPO-Extended. Click on Apply at the bottom of the menu to save your settings.

    A region containing the SNP (highlighted in red and placed in the centre) and its flanking sequence are displayed. The T allele is conserved in all but two of the eutherian mammals displayed.

  4. Click Phenotype data in the left-hand panel.

    This variation is associated with multiple sclerosis, celiac disease and white blood cell count. There are known risk alleles for all three diseases and the corresponding P values are provided. The allele A is associated with celiac disease. Note that the alleles reported by Ensembl are T/C. Ensembl reports alleles on the forward strand. This suggests that A was reported on the reverse strand in the original paper. Similarly, one of the alleles reported for Multiple sclerosis is G.

Exploring VNTR in human

Variable number tandem repeats (VNTRs) show high variation in the number of repeats in the population and are commonly used in forensics (DNA fingerprinting) and to study genetic diversity. (a) Go to the region from 3074666 to 3075100 bp on human chromosome 4. Which gene does it overlap? Which exon of this gene falls in this region?

(b) Configure this page to turn on Repeats (low), Simple repeats (Repeats (low)) and Tandem repeats (TRF) tracks in this view. Can you see any repeats in this exon? What tools were used to annotate the repeats according to the track information?

(c) Zoom in on the (CAG)n to see its sequence. How many CAG repeats can you see in the human reference assembly? Does this track overlap any phenotype-associated variants? What is the identifier of this variant?

(d) Go to the variant tab of the phenotype-associated variant. What is the consequence ontology of this variant? Does the reference allele match the number of repeats you have just counted? What is the shortest and longest allele?

(a) Select Search: Human and type 4:3074666-3075100 in the text box (or alternatively type human 4:3074666-3075100 in the text box). Click Go.

Click on the golden transcript falling in this region. You can see it’s exon 1 of 67 of the huntingtin gene (HTT).

(b) Click Configure this page in the side menu then select: Repeats (low), Simple repeats (Repeats (low)) and Tandem repeats (TRF).

There are three tandem repeats in this exon, and two simple repeats (low); (CAG)n and (CCG)n. Click on the track names to find more about the tools used for annotation: RepeatMasker and Tandem Repeats Finder.

(c) Draw with your mouse a box around the (CAG)n repeat. Click on Jump to region in the pop-up menu.

There are 19 CAG repeats in the human reference sequence overlapping rs71180116 indicated by a pink bar in the All phenotype-associated - short variants (SNPs and indels) track.

(d) Click on the rs71180116 ID to go to the variant tab. You can see in the summary page that this variant is classified as an inframe insertion. Either click + to show all of the alleles in the summary page or go to the Genes and regulation table. This variant has many alternative alleles which differ in the number of repeats. The first allele in the expanded Alleles section of the summary page or the first allele in the Codons column in the Genes and regulation table is the reference allele. It is composed of 19 CAG repeats just as in the Region in detail view. The shortest allele has 7 repeats, the longest has 55 repeats.

Exploring a SNP in mouse

In the paper “Altered metabolic signature in pre-diabetic NOD mice” (PloS One. 2012; 7(4): e35445), Madsen et al. have described several regulatory and coding SNPs, some of them in genes involved in ATP and adenosine metabolism, leading to potentially faulty metabolism of ATP and adenosine. The authors describe that one of the identified SNPs in the murine Entpd2 gene (rs28232063) would lead to increased amounts of available ATP, an immune activator, causing increased cell activation and possibly autoreactive T-cell activation. Use Ensembl to answer the following questions:

  1. Where is the SNP located (chromosome and coordinates)?

  2. What is the HGVS recommendation nomenclature for this SNP?

  3. Why does Ensembl put the G allele first (G/A)?

  4. Are there differences between the genotypes reported in C57BL/6NJ and NOD/ShiLtJ, according to the Mouse Genomes Project?

  1. From the Ensembl homepage, select Mouse from the Species search drop-down and enter rs28232063 in the search box.

    SNP rs28232063 is located on 2:25288362. In Ensembl, its alleles are provided relative to the forward strand.

  2. Click on Show under HGVS names to reveal information about HGVS nomenclature.

    This SNP has got four HGVS names, one at the genomic DNA level (NC_000068.8:g.25288362G>A), two at the transcript level (ENSMUST00000148859.2:n.444-182G>A and ENSMUST00000028328.3:c.446G>A) and one at the protein level (ENSMUSP00000028328.3:p.Arg149Gln).

  3. In Ensembl, the allele that is present in the reference genome assembly is always put first.

    G is the allele for the reference mouse genome strain C57BL/6J

  4. Click on Sample genotypes is the left-hand panel. The table shows genotypes reported for different mouse strains from the Mouse Genomes Project.

    There are indeed differences between the genotypes reported in those two different strains. The genotype reported in C57BL/6NJ is G/G whereas in NOD/ShiLtJ the genotype is A/A.

Variation data in tomato

  1. Go to Ensembl Plants and find the Solyc02g084570.3 gene in Solanum lycopersicum (tomato) and go to its Location tab. Can you see the variation track?

  2. Zoom in around the last exon of this gene. What are the different types of variants seen in that region? Are any splice region variants mapped in the region? If so, what is/are the coordinate(s)?

  1. Select Solanum lycopersicum from the Species search drop-down menu and search for Solyc02g084570.3. In the results page, you can click on the coordinates 2:48284598-48288482 to go straight to the Location tab. Scroll down to the Region in detail view. The variation track is shown at the bottom of the view.

    If you don’t see the Variation - All sources track, click Configure this page on the left-hand panel, search for the track in the pop-up menu and enable the track by clicking on the square next to the track name. Close the pop-up window and wait for the track to load.

  2. Zoom in around the last exon of this gene by drawing a box in the respective region (you can change your mouse action by clicking the Drag/Select icons at the top right-hand corner of the view). Note the gene is on the reverse strand (this is signified by the < sign next to the transcript name, and it is located below the Contigs track), so the last exon will be on the left hand side of that image. The variation legend is shown at the bottom of the page, telling you what the colours mean.

    The types of variants seen in that region are 3’ UTR, missense, synonymous and splice region variants.

    Splice region variants are shown in orange. Click on the variants to get additional information on that variant including location. You can zoom into the region if the variant block is too small to click.

    The variants are found at 2:48285642 and 2:48285640-48285641. Note that the two variants overlap: one is a SNP and the other is an indel. SNPs are tagged with ambiguity codes (zoom into the region if you cannot see this). You can find a useful IUPAC ambiguity code guid on the bioinformatics.org website. Single-letter ambiguity codes are given when two or more possible nucleotides may be represented at a single base locus.

Variation data in Fusarium oxysporum

  1. How many species in Ensembl Fungi have variation data?

  2. Select Fusarium oxysporum (FO2) and search for the FOXG_13574T0 gene. One of its upstream variants is SNP tmp_10_6610. What are the possible alleles for this polymorphic position? Which one is on the reference genome?

  3. What is the most frequent allele at this position?

  4. Which samples have the genotypes C|T and T|T?

  1. Go to Ensembl Fungi, click on View full list of all species. You can sort the table by column. Click on the Variation database column to sort the table by species with variation data.

    The table shows that we have 8 fungi species currently with variation databases.

  2. Click on Fusarium oxysporum in the table and on the species page search for FOXG_13574T0. From the Gene tab, click on Variant table in the left-hand panel. You can use the filter at the top right-hand corner of the table tmp_10_6610.

    The alleles are C/T, where C is the reference allele.

  3. Click on tmp_10_6610 in the table to open the Variant tab. Then click on Genotype frequency from the menu on the left-hand side of the page.

    The most frequent allele at this position is C with a frequency of 0.850.

  4. Click on Sample genotypes in the menu on the left.

    The table shows that sample 909454 has the C|T genotype and 909455 has the T|T genotype.

VEP

We have identified five variants on human chromosome nine, C-> A at 128203516, an A deletion at 128328461, C->A at 128322349, C->G at 128323079 and G->A at 128322917.

We will use the Ensembl VEP to determine:

  • Have my variants already been annotated in Ensembl?
  • What genes are affected by my variants?
  • Do any of my variants affect gene regulation?

Go to the front page of Ensembl and click on the Variant Effect Predictor.

This page contains information about the VEP, including links to download the script version of the tool. Click on Launch VEP to open the input form:

The data is in VCF format:
chromosome coordinate id reference alternative

Put the following into the Paste data box:
9 128328460 var1 TA T
9 128322349 var2 C A
9 128323079 var3 C G
9 128322917 var4 G A
9 128203516 var5 C A

The VEP will automatically detect that the data is in VCF.

There are further options that you can choose for your output. These are categorised as Identifiers, Variants and frequency data, Additional annotations, Predictions, Filtering options and Advanced options. Let’s open all the menus and take a look.

Hover over the options to see definitions.

We’re going to select some options:

  • HGVS, annotation of variants in terms of the transcripts and proteins they affect, commonly-used by the clinical community
  • Phenotypes
  • Protein domains

When you’ve selected everything you need, scroll right to the bottom and click Run.

The display will show you the status of your job. It will say Queued, then automatically switch to Done when the job is done, you do not need to refresh the page. You can edit or discard your job at this time. If you have submitted multiple jobs, they will all appear here.

Click View results once your job is done.

In your results you will see a graphical summary of your data, as well as a table of your results.

The results table is enormous and detailed, so we’re going to go through the it by section. The first column is Uploaded variant. If your input data contains IDs, like ours does, the ID is listed here. If your input data is only loci, this column will contain the locus and alleles of the variant. You’ll notice that the variants are not neccessarily in the order they were in in your input. You’ll also see that there are multiple lines in the table for each variant, with each line representing one transcript or other feature the variant affects.

You can mouse over any column name to get a definition of what is shown.

The next few columns give the information about the feature the variant affects, including the consequence. Where the feature is a transcript, you will see the gene symbol and stable ID and the transcript stable ID and biotype. Where the feature is a regulatory feature, you will get the stable ID and type. For a transcription factor binding motif (labelled as a MotifFeature) you will see just the ID. Most of the IDs are links to take you to the gene, transcript or regulatory feature homepage.

This is followed by details on the effects on transcripts, including the position of the variant in terms of the exon number, cDNA, CDS and protein, the amino acid and codon change, transcript flags, such as MANE, on the transcript, which can be used to choose a single transcript for variant reporting, and pathogenicity scores. The pathogenicity scores are shown as numbers with coloured highlights to indicate the prediction, and you can mouse-over the scores to get the prediction in words. Two options that we selected in the input form are the HGVS notation, which is shown to the left of the image below and can be used for reporting, and the Domains to the right. The Domains list the proteins domains found, and where there is available, provide a link to the 3D protein model which will launch a LiteMol viewer, highlighting the variant position.

Where the variant is known, the ID of the existing variant is listed, with a link out to the variant homepage. In this example, only rsIDs from dbSNP are shown, but sometimes you will see IDs from other sources such as COSMIC. The VEP also looks up the variant in the Ensembl database and pulls back the allele frequency (AF in the table), which will give you the 1000 Genomes Global Allele Frequency. In our query, we have not selected allele frequencies from the continental 1000 Genomes populations or from gnomAD, but these could also be shown here. We can also see ClinVar clinical significance and the phenotypes associated with known variants or with the genes affected by the variants, with the variant ID listed for variant associations and the gene ID listed for gene associations, along with the source of the association.

For variants that affect transcription factor binding motifs, there are columns that show the effect on motifs (you may need to click on Show/hide columns at the top left of the table to display these). Here you can see the position of the variant in the motif, if the change increases or decreases the binding affinity of the motif and the transcription factors that bind the motif.

Above the table is the Filter option, which allows you to filter by any column in the table. You can select a column from the drop-down, then a logic option from the next drop-down, then type in your filter to the following box. We’ll try a filter of Consequence, followed by is then missense_variant, which will give us only variants that change the amino acid sequence of the protein. You’ll notice that as you type missense_variant, the VEP will make suggestions for an autocomplete.

You can export your VEP results in various formats, including VCF. When you export as VCF, you’ll get all the VEP annotation listed under CSQ in the INFO column. After filtering your data, you’ll see that you have the option to export only the filtered data. You can also drop all the genes you’ve found into the Gene BioMart, or all the known variants into the Variation BioMart to export further information about them.

Running CFTR variants through VEP

Resequencing of the genomic region of the human CFTR (cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7) gene (ENSG00000001626) has revealed the following variants. The alleles defined in the forward strand:

  • G/A at 7: 117,530,985
  • T/C at 7: 117,531,038
  • T/C at 7: 117,531,068

Use the VEP tool in Ensembl and choose the options to see SIFT and PolyPhen predictions. Do these variants result in a change in the proteins encoded by any of the Ensembl genes? Which gene? Have the variants already been found?

Go to the Ensembl homepage and click on the link Tools at the top of the page. Currently there are nine tools listed in that page. Click on Variant Effect Predictor and enter the three variants as below:

7	117530985	117530985	G/A
7	117531038	117531038	T/C  
7	117531068	117531068	T/C

Note: Variation data input can be done in a variety of formats. See more details about the different data formats and their structure in this VEP documentation page. Click Run. When your job is listed as Done, click View Results.

You will get a table with the consequence terms from the Sequence Ontology project (http://www.sequenceontology.org/) (i.e. synonymous, missense, downstream, intronic, 5’ UTR, 3’ UTR, etc) provided by VEP for the listed SNPs. You can also upload the VEP results as a track and view them on Location pages in Ensembl. SIFT and PolyPhen are available for missense SNPs only. For two of the entered positions, the variations have been predicted to have missense consequences of various pathogenicity (coordinate 117531038 and 117531068), both affecting CFTR. All the three variants have been already annotated and are known as rs1800077, rs1800078 and rs35516286 in dbSNP (databases, literature, etc).

VEP cdk5r1b Atlantic salmon

We have identified a few variants in Atlantic salmon (Salmo salar):

  • chr 28, genomic coordinate 1777645, alleles C/T
  • chr 28, genomic coordinate 1777906, alleles G/A
  • chr 28, genomic coordinate 1786995, alleles T/G

(a) Which genes and transcripts do these variants map to?

(b) Do these variants result in a change in the proteins encoded by any of the Ensembl genes? Which genes?

Go to www.ensembl.org and click on the Variant Effect Predictor link on the homepage. Click Launch VEP.

Choose Atlantic salmon as the species and copy the following into the Paste data text box:

28 1777645 1777645 C/T var1.
28 1777906 1777906 G/A var2.
28 1786995 1786995 T/G var3.

Note: Variation data input can be done in a variety of formats. See more details here http://www.ensembl.org/info/docs/variation/vep/vep_formats.html

Click Run.

When your job is listed as Done, click View Results.

You will get a table with the consequence terms from the Sequence Ontology project (http://www.sequenceontology.org/) (i.e. synonymous, missense, downstream, intronic, 5’ UTR, 3’ UTR, etc) provided by VEP for the listed SNPs. You can also upload the VEP results as a track and view them on Location pages in Ensembl.

The variants overlaps three genes (six transcripts of psmd11b, four transcripts of cdk5r1b and one transcript of ENSSSAG00000096896 gene)

Variant 28_1777906_G/A overlaps cdk5r1b gene and resulted in amino acid change at position 109 and 116 (Ser to Leu), variant 28_1777645_C/T also overlaps cdk5r1b gene and resulted in amino acid change at position 96 and 203 (Arg to His).

Web VEP analysis of variants in Oryza sativa Japonica (rice)

You’ll find a VCF file here. This is a small subset of the outcome of Oryza sativa Japonica whole-genome sequencing and variant-calling experiment. Analyse the variants in this file with the VEP tool in Ensembl Plants and determine the following:

  1. How many genes and transcripts are affected by variants in this file?

  2. Do these variants result in a change in the proteins encoded by any of the Ensembl genes? Which genes are affected? What is the amino acid change? What is the pathogenicity prediction score for this change?

Go to Ensembl Plants and click on Tools at the top of the page. Click on Variant Effect Predictor and select Oryza sativa Japonica Group from the Species menu.

Either click on Choose file and select the file to upload it, or directly paste the URL into the Or provide file URL: box. Click Run at the bottom of the page. When your job is done, click View results.

  1. The number of affected genes and transcripts is shown in the Summary statistics table at the top.

    8 genes and 8 transcripts are affected by these variants.

  2. Use the filters to view only missense variants. The filters are found above the detailed results table in the middle. Select Consequence and is from the drop-down menus. Then type missense_variant into the boxe. Add to apply your filter.

    1 variant is a missense variant. It causes a leucine to arginine (L/R) at position 16 change in the gene OS09G0103500. The SIFT score is 0.01 (Deleterious low confidence). Refere to this link for more information on SIFT (https://sift.bii.a-star.edu.sg/).

Web VEP analysis of variants in Triticum aestivum (wheat)

You have done whole-genome sequencing and variant-calling experiments for Triticum aestivum. You have a VCF file with a small subset of variants from this experiment. Analyse the variants in this file with the VEP tool in Ensembl Plants and determine the following:

  1. How many variants were analysed? How many are novel?

  2. How many genes and transcripts are affected by variants in this file?

  3. Do any of the variants have different consequences for different transcripts?

  4. Filter the table to find variants with high impact. How many variants have high impact? Why do you think missense variants are not classified as high impact?

  5. Can you export all the results to a VCF file? Compare it to the input VCF file to see what information the VEP adds.

Go to any Ensembl Plants page and click on Tools in the navigation bar at the top of the page. Click on Variant Effect Predictor and change your species to Triticum aestivum by clicking on Change species.

Enter a descriptive name for your VEP job. If you have downloaded the variant file to your local machine, click on Choose file to upload. Alternatively, you can paste the URL for the file into the Or provide file URL: box. Click Run at the bottom of the page. When your job is done, click View reesults.

  1. 20 variants were analysed, of which 1 is novel.

  2. Only 1 gene is affected by variants in this file. The gene has 2 transcripts and both are affected by the variants.

  3. You can find a list of calculated variant consequences and their impact here.

    Yes, the novel variant results in a stop_lost in TraesCS3A02G301400.1 and is a downstream_gene_variant for TraesCS3A02G301400.2.

  4. Use the filters to view only variants with HIGH impact (you may need to add the column under Show/hide columns at the top of the table if you cannot find it). The filters are found above the detailed results table in the middle. Select Impact and is from the drop-down menus. Then type HIGH into the box; this will autocomplete. Click Add.

    There are 3 variants with high impact and all three are stop altering. Missense variants are not classified as high impact, because they do not always have significant impacts on protein functions. Usually the protein is still produced. In contrast, stop altering variants affect the protein length, and therefore likely affect the protein function.

  5. At the top right of the table there is an option to download data. Click on VCF for the All option. Open the VCF file you have downloaded in a text editor. You can see that VEP adds annotation in the INFO column of the VCF file.

VEP analysis of variants in Verticillium dahliae

Verticillium wilt caused by Verticillium dahliae is a notorious soil-borne fungal disease that threatens the yield of economic crops worldwide. We have identified four variants in Verticillium dahliae JR2 chromosome 5:

  • C->G at 698711
  • G->T at 698935
  • G->A at 700313
  • C->A at 701484

Use VEP in Ensembl Fungi to answer the following questions:

  1. Have these variants already been annotated in Ensembl?

  2. What genes are affected by the variants? What are their gene IDs?

  3. Are any of the variants predicted to be missense variants?

Go to any Ensembl Fungi page and click on Tools in the navigation bar at the top of the page. Click on Variant Effect Predictor and change your species to Verticillium dahliae JR2 by clicking on Change species.

Enter a descriptive name for your VEP job. You will need to convert your variants into one of VEP’s supported input formats. We have converted the variants into the Ensembl default format below. Paste the variants into Input data:.

5 698711 698711 C/G
5 698935 698935 G/T
5 700313 700313 G/A
5 701484 701484 C/A

Click Run at the bottom of the page. When your job is done, click View reesults.

  1. You can find the number of existing and novel variants in the Summary statistics of the results.

    4 variants were analysed, of which 3 are novel.

  2. You can also find the number of overlapped genes in the Summary statistics.

    4 genes are affected.

    Sort the table by Gene by clicking on the column name. Count the number of unique gene IDs.

    The gene IDs are: VDAG_JR2_Chr5g02150a, VDAG_JR2_Chr5g02160a, VDAG_JR2_Chr5g02170a and VDAG_JR2_Chr5g02171a.

  3. Filter the table as follows: Consequence is missense_variant.

    Yes, the third variant (5_700313_G/A) is predicted to have a missense effect on gene VDAG_JR2_Chr5g02170a.

VEP in Ensembl Bacteria

In Ensembl Bacteria the genome for Bacteroides fragilis 638R and launch the VEP tool. Use VEP to predict the effects of a 7 bp deletion of TCTACAA on the supercontig FQ312004 at the position 258140-258146. Use the results to answer the following questions:

  1. How many genes does the indel overlap? What are their gene symbols?

  2. What is the most common consequence of the variant?

  3. What is the most severe consequence? What gene does it affect and what does it do?

Type Bacteroides fragilis 638R into the species search box, then select the genome. You are now in the species information page. Click on Variant Effect Predictor at the bottom left. Next, you want to make sure your variant is in one of VEP’s supported variant formats. We have converted the variant into the Ensembl default VEP format. You can enter the following into the input box: FQ312004 258140 258146 TCTACAA/- +

Make sure you name your VEP job something descriptive, so it’s easier for you to find later on. Click Run to get the results.

  1. Find the number of overlapped genes in the Summary statistics. You can find their gene symbols under the Symbol column in the table below.

    The indel overlaps 14 different genes. 12 have the following symbols assigned to them: traA, traD, traE, traF, traG, traI, traJ, traK, traL, traM, traN and traO. 2 genes do not have a gene symbol.

  2. Sort the table by Consequence by clicking on the column name.

    The most common consequences are downstream_gene_variant (n=6) and upstream_gene_variant (n=6).

  3. You can find a list of calculated consequences sorted by severity in the [Ensembl Variation documentation](https://www.ensembl.org/info/genome/variation/prediction/predicted_data.html#consequences).

    According to the calculated variant consequence list, the most severe consequence is frameshift_variant on the traI gene. The gene is a putative conjugative transposon protein traI.

Comparative genomics

Let’s look at the homologues of human BRCA2. Search for the gene and go to the Gene tab.

Click on Gene tree, which will display the current gene in the context of a phylogenetic tree used to determine orthologues and paralogues.

Funnels indicate collapsed nodes. We can expand them by clicking on the node and selecting Expand this sub-tree from the pop-up menu.

We can also see the alignment of the sub-tree by clicking on Wasabi viewer, which will open a pop-up:

You can download the tree in a variety of formats. Click on the download icon in the bar at the top of the image to get a pop-up where you can choose your format.

We can look at homologues in the Orthologues and Paralogues pages, which can be accessed from the left-hand menu. If there are no orthologues or paralogues, then the name will be greyed out. Paralogues is greyed out for BRCA2 indicating that there are no paralogues available. Click on Orthologues to see the 175 orthologues available.

Choose to see only Rodents and related species orthologues by selecting the box. The table below will now only show details of rodent orthologues. Let’s look at mouse.

Links from the orthologue allow you to go to alignments of the orthologous proteins and cDNAs. Click on View Sequence Alignments then View Protein Alignment for the mouse orthologue.

Let’s look at some of the comparative genomics views in the Location tab. Go to the region 2:176087000-176202000 in human, which contains the HoxD cluster which is involved in limb development and is highly conserved between species.

You can turn on conservation scores and constrained elements. Click on Configure this page, then Comparative genomics and turn on the tracks for Constrained elements for 91 eutherian mammals EPO-Extended and Conservation score for 91 eutherian mammals EPO-Extended. Save and close the menu.

You can now see the conservation scores in pale pink. These were used to determine the peaks indicated in the constrained elements track in dark pink. This track indicates regions of high conservation between species, considered to be “constrained” by evolution.

We can also look at individual species comparative genomics tracks in this view by clicking on Configure this page.

Select BLASTz/LASTz alignments from the left-hand menu to choose alignments between closely related species. Turn on the alignments for Mouse, Chicken and Chimpanzee in Normal. Save and close the menu.

The alignment is greatest between closely related species.

We can also look at the alignment between species or groups of species as text. Click on Alignments (text) in the left hand menu.

Select Select an alignment to open the alignment menu.

Click through the links, Pairwise, Rodents & Lagomorphs, Rats and Mice to select Mouse reference (CL57BL6).

In this case there are two blocks aligned, Block 1 a large (115001 bp) alignment against mouse chr2 and one smaller block against mouse chr7. Click on Block 1.

You will see a list of the regions aligned, followed by the sequence alignment. Click on Display full alignment. Exons are shown in red.

To compare with both contigs visually, go to Region comparison.

To add species to this view, click on the blue Select species or regions button. Choose Mouse Reference again then close the menu.

You can configure this view for both species. Click on Configure this page and look in the top left of the menu.

The drop down allows you to configure each species separately.

We can view large scale syntenic regions from our chromosome of interest. Click on Synteny in the left hand menu.

Orthologues and gene trees for the human BRAF gene

Go to Ensembl to answer the following questions:

  1. How many orthologues are predicted for the human BRAF in primates? How much sequence identity does the Carlito syrichta (tarsier) protein have to the human one? Can you tell which end of the BRAF protein is more conserved between these two species by looking at the orthologue alignment?

  2. Go to the Gene tree for this gene. View the Wasabi alignment of all the proteins in primates. Can you see a large gap in the alignment around position 450? Which species match the human sequence?

  1. From the Ensembl homepage, choose Human from the drop-down list and search for BRAF. Click through to the Gene tab view. Click on Orthologues at the left side of the page to see all the orthologous genes.

    There are 1:1 orthologues in 22 primates reported in the summary table.

    Search for Tarsier in the table below.

    The percentage of identical amino acids in the tarsier protein (the orthologue) compared with the gene of interest. i.e. human BRAF (the target species/gene) is 95.39%. This is known as the Target%id. The identity of the gene of interest (human BRAF) when compared with the orthologue (tarsier BRAF, the query species/gene) is 94.65% (the Query %id). Note the difference in the values of the Target and Query %id reflects the different protein lengths for the human and tarsier BRAF genes.

    Click on the View Sequence Alignments link in the Orthologue column to View Protein Alignment in Clustal W format.

    Conserved amino acids are indicated by asteriks. The alignment around the N-terminus looks poorer, when compared to the C-terminus end.

  2. Click on Gene tree in the left hand menu. All of the primates are enclosed in a lilac box. Click on the furthest left node in the box to get a pop-up labelled Primates. Alternatively, scroll to the bottom of the page, and select Order from Collapse all the nodes at the taxonomic rank. Primates will appear as a red triangle. Click on Wasabi viewer in the pop-up menu to see the alignment. Scroll to position 450.

    Greater bamboo lemur, mouse lemur, Sumatran orangutan, crab-eating macaque, olive baboon, Bolivian squirrel monkey, white-tufted-ear marmoset and Ma’s night monkey all match the human sequence.

Whole genome alignments

(a) Find the human BRCA2 gene and go to the Region in detail page. Turn on the BLASTz/LASTz alignment tracks for chicken, chimp, mouse and platypus. Does the degree of conservation between human and the various other species reflect their evolutionary relationship? Which parts of the BRCA2 gene seem to be the most conserved? Did you expect this?

(b) Have a look at the Conservation score and Constrained elements tracks for the set of 90 eutherian mammals and 65 amniota vertebrates. Do these tracks confirm what you already saw in the pairwise alignment tracks?

(c) Retrieve the genomic alignment (text) across 65 amniotes for a constrained element matching up with exon 15 of the golden transcript. Highlight the bases that match in >50% of the species in the alignment. Is this sequence exonic in all species?

(a) Select Human from the species selector drop-down list and type brca2 in the search box. Click Go. Click on 13:32315086-32400268:1 below BRCA2 (Human Gene) to go to the Region in detail page.

Click Configure this page in the side menu, then BLASTz/LASTz alignments under the Comparative genomics menu. Select Chicken, Chimpanzee, Mouse and Platypus in Normal style.

Yes, the degree of conservation does reflect the evolutionary relationship between human and the other species; the highest degree of conservation is found in chimp, followed by mouse, platypus and chicken, respectively.

Especially the exonic sequences of BRCA2 seem to be highly conserved between the various species, which is what is to be expected because these are supposed to be under higher selection pressure than intronic and intergenic sequences.

(b) Click Configure this page in the side menu, then Conservation regions under the Comparative genomics menu.

Select Conservation score and Constrained elements for 90 eutherian mammals EPO-Extended and 65 amniota vertebrates Mercator-Pecan.

Both the Conservation score and Constrained elements tracks largely correspond with the data seen in the pairwise alignment tracks; all exons of the BRCA2 gene show a high degree of conservation (note the UTRs which are not conserved).

(c) Click on exons of the golden transcript (ENST00000380152) to reveal their rank in transcript. Exon 15 can be found in the middle. Click on a constrained element in 65 way GERP elements track matching up with this exon.

Click on View alignments (text) in the pop-up menu, then Configure this page in the side menu. Select Show conservation regions to highlight bases matching in majority of the species in this alignment.

Exons are indicated by red lettering. All but Naja naja (Indian cobra) and Pseudonaja textilis (Eastern brown snake) have exonic sequence in this region.

Exploring a genomic region between in mouse and human

You find a deletion in the mouse genome that severely affects development, and you want to investigate it. In Ensembl, go to this region (base pair coordinates 136197000-136283000 on mouse chromosome 4).

  1. How many protein coding transcripts does the gene in this region have?

  2. You want to see if any of these transcripts might be expressed in brain tissue. Turn on the RNASeq gene model for brain.

  3. Find this same view (Region in Detail) for the human orthologue of the mouse gene.

  4. To understand crucial variants, you want to investigate if there are any missense variants in the most diverse population available. Turn on the 1000 Genomes AFR (African population) track.

  1. Go to the Ensembl homepage, select Mouse from the Species search drop-down and type 4:136197000-136283000 in the text box. Alternatively, you can leave the Species search drop-down list like it is and type mouse 4:136462271-136562270 in the text box. Click Go.

    This region encodes the Luzp1 gene, which has six protein-coding transcripts (splice variants).

  2. Click Configure this page in the side menu (or on the cog wheel icon in the top left-hand side of the bottom image). Click RNASeq models in the left hand menu. Click on the box in the matrix for Brain: Gene model. Turn it on, using Expanded with labels. Close the menu.

    There is a gene model based on RNASeq evidence that matches to Luzp1-004.

  3. There are several ways to do this. One way is to click on a Luzp1 transcript, and in the pop-up menu, click on the gene ID ENSMUSG00000001089. This should bring you to the Gene tab for mouse Luzp1. In the left hand menu, click Orthologues. Find the human orthologue in the list, and click on its location 1:23410516-23504301:-1. You should be in the Region in detail view for human, showing Luzp1 transcripts.

  4. Click Configure this page in the side menu. Type 1000 in the Find a track text box. Select 1000 Genomes - AFR Save and close the new configuration by clicking on ✓ (or anywhere outside the pop-up window).

    There are many missense variants (coloured yellow) in these transcripts.

Finding orthologues and gene trees of the Arabidopsis thaliana FUM1 gene

The fumarase gene FUM1 in Arabidopsis thaliana encodes a protein with mitochondrial targeting information. Read more in this UniProt entry. Go to Ensembl Plants to answer the following questions:

  1. How many orthologues have been identified for this gene?

  2. Which orthologue has the highest sequence similarity? Look at the Query%ID and Target%ID.

  1. Go to Ensembl Plants, select Arabidopsis thaliana from the Favourite genomes section on the homepage. Search for FUM1. Click on the gene ID AT2G47510. Now click on Plant Compara: Orthologues on the left-hand panel to see all orthologues of this gene. You can find the number of orthologues in the summary information at the top of the page.

    FUM1 has 166 orthologues in Ensembl Plants.

  2. Click on the triangles in the table column headers to sort by identity. If you are unsure of what data the column is show, you can mouse-over the headers for a description.

    The orthologue with the highest sequence similarity is from Arabidopsis halleri.

Homologues and gene trees for the Triticum aestivum (wheat) RHT1 gene

Go to Ensembl Plants and answer the following questions:

  1. How many orthologues are predicted for the Triticum aestivum (wheat) gene RHT1 (gene ID TraesCS4D02G040400) gene in Liliopsida?

  2. How much sequence identity does the Secale cereale (rye) protein have to the maize one?

  3. Download the alignment in Nexus format.

  4. Open the gene tree for the wheat RHT1 gene. What is the gene tree ID?

  5. How many speciation and duplication nodes does the phylogeny have?

Go to the Ensembl Plants homepage, select Triticum aestivum from the Species drop-down and search for TraesCS4D02G040400. Click through to the Gene tab. On the Gene tab, click on Plant Compara: Orthologues at the left-hand side of the page to see all the orthologous genes.

  1. These are the orthologues in the Liliopsida:
    • 24 1-to-1
    • 9 1-to-many
    • 0 many-to-many
  2. Filter the table by entering Secale cereale in the filter box on the top right-hand corner of the table.

    The percentage of identical amino acids in the rye protein (the orthologue) compared with the gene of interest (i.e. wheat RHT1; the target species/gene) is 98.71%. This is known as the Target %ID. The identity of the gene of interest (wheat RHT1) when compared with the orthologue (the rye gene, i.e. the query species/gene) is 97.91% (the query %ID).
    Note the differences in the values of the Target and Query % ID reflects the different protein lengths for the genes.

  3. Click on View Sequence Alignments in the Orthologue column. Select View Protein Alignment from the pop-up menu. Click on the green Download homology button above the table and select Nexus. Click on Download or Download Compressed to save the alignment on your local machine.

  4. Go to Plant Compara: Gene tree in the left-hand menu. You can find the gene tree ID above the phylogeny.

    The gene tree ID is EPlGT00940000163877.

  5. You can find some summary statistics below the gene ID.

    There are 418 speciation nodes and 149 duplication nodes.

Exploring whole-genome alignments for Triticum aestivum (wheat)

Go to Ensembl Plants and answer the following questions:

  1. Find the TraesCS2D02G080000 gene in Triticum aestivum (wheat). What is the function for this gene and what are its coordinates?

  2. Go to the Location tab. Turn on the LASTZ-net alignment tracks for Arabidopsis thaliana, Zea mays (corn) and Sorghum bicolor (great millet). Are there any regions where you can see gaps in in some of the species alignments?

  3. Go to the Region comparison view and compare to A. thaliana. What occurs at this gap in the alignment?

  4. Export the Block 2 alignment between T. aestivum and A. thaliana in ClustalW format.

  1. Go to the Ensembl Plants homepage. Select Triticum aestivum from the Species drop-down, enter TraesCS2D02G080000 in the search box and click Go. Open the Gene tab.

    The gene description is as follows: Ascorbate peroxidase, ROS homeostasis, Chloroplast protection, Carbohydrate metabolism, Plant architecture, Fertility maintenance. This was projected from Oryza sativa (Os07g0694700).

  2. Go the Location tab in the top left-hand corner. Click on CConfigure this page in the side menu. Open Comparative genomics: BLASTz/LASTz alignments in the pop-up menu. Turn on the tracks for Arabidopsis thaliana, Zea mays (corn) and Sorghum bicolor (great millet) in the Normal style. Save and close the pop-up menu

    There is alignment across most of the coding regions, with some gaps occurring in all 3 species. These gaps map with the intronic regions of the T. aestivum gene.

  3. Click on Comparative Genomics: Region Comparison in the left-hand menu. Go to the Select species or regions button and add A. thaliana. Save and close the menu.

    The gap in the alignment translates to the intronic regions of the T. aestivum gene.

  4. Go to Comparative Genomics: Alignments (text) and select A. thaliana from the Alignment drop-down. Click on the green Download alignment button and select ClustalW. Download the file to your local machine either in a compressed format, or as it is by clicking the green Download button above the file format preview.

Finding orthologous genes for a root transporter in Oryza sativa Japonica (rice)

Search Ensembl Plants for the gene Lsi1 in Oryza sativa Japonica Group (rice). This gene is known to code for an aquaporin transporter that facilitates the uptake of silicon and arsenic through the roots. Silicon concentration is highest in grass species, and is associated with defence.

  1. From the gene tab, go to the Orthologues page under Plant Compara. Which plant group has the highest number of 1-to-1 orthologues? Is it the same group that has the highest number of 1-to-many orthologues?

  2. Reduce the orthologues table to look only at Triticum aestivum (wheat) orthologues. Why are there three results for a 1-to-1 orthologue?

  3. Click on the Compare regions link for chromosome 6B region in wheat to go to the Location tab. Scroll to the bottom image. How do the gene models compare between the species? Do they have the same number of exons?

  4. Click back to the Gene tab and click on the Gene gain/loss tree page. Which species has the highest number of members of this gene family? Is it a grass? Can you change the view to see a radial tree?

Go to Ensembl Plants. Look for the main search box highlighted in green. Select Oryza sativa Japonica Group from the drop-down box and type in Lsi1. Click Go and click on the gene ID Os02g0745100.

  1. Go to Plant Compara: Orthologues on the left-hand panel.

    Liliopsida has 24 1-to-1 orthologues, the only group with 1-to-1 orthologues. This group is synonymous with Monocotyledon, so the group that contains the grasses. Eudicotyledons has the highest number of 1-to-many orthologues, indicating that this gene has been duplicated in the eudicots.

  2. Use the search box in the top right-hand corner of the Selected orthologues table and enter Triticum aestivum, the table should automatically filter.

    There are 3 results, one for each component (A,B,D). Note that these are considered 1-to-1 orthologues, rather than 1-to-many. This is because these genes arose in wheat by hybridisation (allopolyploidy), rather than duplication (autopolyploidy).

  3. Click on Compare regions (found in the 3rd column below the gene identifier) from the 2nd result for component 6B. This takes us to the Location tab. Scroll down to the bottom of the page.

    Both genes have 5 exons and the same structure. This looks unusual because the gene in rice is on the forward strand, while the gene in wheat is on the reverse strand. This is reflected in the crossing green links between the pink alignment blocks.

  4. Click on the Gene tab at the top of the page and click on Gene gain/loss tree in the left-hand panel.

    Significant expansions are shown with red branches, and the number of genes in the family shown in the count next to the image and species name. We can see that Echinochloa crus-galli (Cockspur grass) has 25 members in this group.

We can change the tree to radial view by clicking on the icon with two arrows at the top left of the image.

Pan-taxonomic comparative genomics data in Ensembl Bacteria

Bacillus subtilis subsp. subtilis str. 168 (GCA_000009045) is a model organism and often used in academic research and in the biotechnology industry as it can produce large amounts of important enzymes, like protease and amylase. It is part of Pan-taxonomic Compara in Ensembl Bacteria. We will use the sipT gene, a type I signal peptidase, as a reference to find the following information:

  1. Find the Ensembl gene tree ID. How many speciation and duplication nodes does it have?

  2. How many orthologues does B. subtilis str. 168 have? What type of orthologues are they?

  3. Does it have an orthologue in Escherichia coli str. K-12 substr. MG1655? If so, what is the gene ID and coordinate in E. coli?

  4. Export the protein alignment of the B. subtilis and E. coli orthologues. What are the different formats you can export the alignment as?

  1. Go to the Ensembl Bacteria homepage and enter Bacillus subtilis subsp. subtilis str. 168 (GCA_000009045) in the Species search bar. In the species information page, enter sipT. Click the gene ID BSU_14410. Under the Gene tab, click on Pan-taxonomic Compara: Gene Tree on the left.

    The Ensembl genetree ID is EGGT00050000013001. There are 92 speciation nodes and 35 duplication nodes.

  2. Go to Pan-taxonomic Compara: Orthologues on the left-hand panel. You can find the number and types of orthologues under the Summary of orthologues of this gene table.

    The B. subtilis str. 168 sipT gene has 56 1-to-many and 15 many-to-many orthologues.

  3. Filter the Selected orthologues table by entering _Escherichia coli_ str. K-12 substr. MG1655 in the search bar in the top right-hand corner of the table.

    Yes, an orthologue is present in E. coli str. K-12 substr. MG1655. The gene ID is b2568 and the its coordinate is 2,704,335-2,705,309.

  4. Click on View Sequence Alignment in the Orthologue column. Select View Protein Alignment from the pop-up menu. Click on the Download homology button.

    Depending on your downstream analyses you may choose to export the alignment in a particular format. In Ensembl, you can export the alignment in the following formats: ClustalW, FASTA, Mega, MSF, Nexus, OrthoXML, Pfam, Phylip, PhyloXML, PSI and Stockholm.

Orthologues of the Schizosaccharomyces pombe Mcm6 gene

Go to the Ensembl Fungi site to find out the following:

  1. How many orthologues and how many paralogues are predicted for the Schizosaccharomyces pombe Mcm6 gene?

  2. How many Schizosaccharomyces orthologues are there?

  3. Does it have a human orthologue? If so what type is it and what is the orthologue’s Ensembl ID?

  1. From the Ensembl Fungi homepage, select Schizosaccharomyces pombe from the Favourite genomes section and search for Mcm6 in the species information page. Alternatively, you can select S. pombe from the Species search drop-down and enter Mcm6. In the search results, click on the gene ID SPBC211.04c to open the Gene tab. Click on Fungal Compara: Orthologues in the left-hand menu to see all the orthologous genes. You can find the number of orthologues and paralogues of the gene in the summary information at the top of the page.

    Mcm6 has 387 orthologues and 4 paralogues.

  2. Use the filter in the top right-hand corner of the table to search for Schizosaccharomyces.

    There are 3 Schizosaccharomyces orthologues: Schizosaccharomyces cryophilus, Schizosaccharomyces japonicus and Schizosaccharomyces octosporus.

  3. Go to Pan-taxonomic Compara, hide the summary table and search for human in the Orthologues table.

    Yes, it is a 1:1 orthologue to the human FH gene (ENSG00000091483).

BioMart

Follow these instructions to guide you through BioMart to answer the following query:

You have three questions about a set of human genes:
ESPN, MYH9, USH1C, CISD2, THRB, WHRN
(these are HGNC gene symbols. More details on the HUGO Gene Nomenclature Committee can be found on http://www.genenames.org)

  1. What are the NCBI Gene IDs for these genes?
  2. Are there associated functions from the GO (gene ontology) project that might help describe their function?
  3. What are their cDNA sequences?

Click on BioMart in the top header of a www.ensembl.org page to go to: www.ensembl.org/biomart/martview

You cannot choose any filters or attributes until you’ve chosen your dataset. Your dataset is the data type you’re working with. In this case we’re going to choose human genes, so pick Ensembl Genes then Human genes from the drop-downs.

Now that you’ve chosen your dataset, the filters and attributes will appear in the column on the left. You can pick these in any order and the options you pick will appear.

Click on Filters on the left to see the available filters appear on the main page. You’ll see that there are loads of categories of Filters to choose from. You can expand these by clicking on them. For our query, we’re going to expand GENE.

Our input data is a list of identifiers, so we’re going to use the Input external references ID list filter. This allows us to input a list of identifiers from different databases. We need to choose what kind of identifier we’re using, so that BioMart can look up the right column in a data table. You can pick these from a drop-down list, which lists the type of identifier with an example of how it looks. For our query, we have a list of gene names, so we need to pick Gene Name(s).

To check if the filters have worked, you can use the Count button at the top left, which will show you how many genes have passed the filter. If you get 0 or another number you don’t expect, this can help you to see if your query was effective.

To choose the attributes, expand this in the menu. There are six categories for human gene attributes. These categories are mutually exclusive, you cannot pick attributes from multiple categories. This means that we need to do two separate queries to get our GO terms and NCBI IDs, and to get our cDNA sequences.

The Ensembl gene and transcript IDs, with and without version numbers are selected by default. The selected attributes are also listed on the left.

We can choose the attributes we want by clicking on them. For our query, we’re going to select:

  • GENE
    • Gene Name
  • EXTERNAL
    • NCBI gene ID
    • GO term accession
    • GO term name
    • GO term definition

We need to select the Gene Name in order to get back our original input, as this is not returned by default in BioMart. The order that you select the attributes in will define the order that the columns appear in in your output table.

You can get your results by clicking on Results at the top left.

The results table just gives you a preview of the first ten lines of your query. This allows the results to load quickly, so that if you need to make any changes to your query, you don’t waste any time. To see the full table you can click on View ## rows. You can also export the data to an xls, tsv, csv or html file. For large queries, it is recommended that you export your data as Compressed web file (notify by email), to ensure your download is not disrupted by connection issues.

You can see multiple rows per gene in your input list, because there are multiple transcripts per gene and multiple GO terms per transcript.

To get the cDNA sequences, go back to the Attributes then select the category Sequences and expand SEQUENCES.

When you select the sequence type, the part of the transcript model you’ve chosen will be highlighted in the grpahic.

Choose cDNA sequences, then expand HEADER INFORMATION to add Gene Name to the header. Then hit Results again.

For more details on BioMart, have a look at this publication:

Kinsella, R.J. et al
Ensembl BioMarts: a hub for data retrieval across taxonomic space.
http://europepmc.org/articles/PMC3170168

Finding genes by protein domain

Find mouse proteins with Signalp cleavage sites located on chromosome 9.

As with all BioMart queries you must select the dataset, set your filters (input) and define your attributes (desired output). For this exercise: Dataset: Ensembl genes in mouse Filters: Signalp cleavage sites on chromosome 9 Attributes: Ensembl gene and transcript IDs and gene names

Go to the Ensembl homepage (http://www.ensembl.org) and click on BioMart at the top of the page. Select Ensembl genes as your database and Mouse genes as the dataset. Click on Filters on the left of the screen and expand REGION. Change the chromosome to 9. Now expand PROTEIN DOMAINS, also under filters, and select Limit to genes, choosing with With Cleavage site (Signalp) from the drop-down and then Only. Clicking on Count should reveal that you have filtered the dataset down to 217 genes.

Click on Attributes and expand GENE. Select Gene name. Now click on Results. The first 10 results are displayed by default; Display all results by selecting ALL from the drop down menu.

The output will display the Ensembl gene ID, Ensembl Transcript ID and gene names of all proteins with a Signalp cleavage site on mouse chromosome 9. If you prefer, you can also export as an Excel sheet by using the Export all results to XLS option.

Exporting homologues with BioMart

Go to Ensembl’s BioMart. For a list of Ciona savignyi Ensembl genes, export the human orthologues:
ENSCSAVG00000000002, ENSCSAVG00000000003, ENSCSAVG00000000006, ENSCSAVG00000000007, ENSCSAVG00000000009, ENSCSAVG00000000011

Do all of these genes have a homologue in human?

  1. Go to BioMart (you can find a shortcut in the navigation bar at the top of any Ensemblpage) and click New. Choose the Ensembl Genes database. Choose the Ciona savignyi genes (CSAV 2.0) dataset.

  2. Click on Filters in the left panel. Expand the GENE. Enter the gene list in the Input external references ID list box. Gene stable ID(s) should be preselected.

  3. Click on Attributes in the left panel. Select the Homologues attributes at the top of the page. Expand the GENE section. Deselect Gene stable ID version, Transcript stable ID and Transcript stable ID version. Expand the ORTHOLOGUES [F-J] section. Select Human gene stable ID.

  4. Click Results. Select View: All rows as HTML.

    All but ENSCSAVG00000000006 have a homologue in human.

Convert IDs using BioMart

BioMart is a very handy tool when you want to convert IDs from different databases. The following is a list of 29 IDs of human proteins from the NCBI RefSeq database:
NP_001218, NP_203125, NP_203124, NP_203126, NP_001007233, NP_150636, NP_150635, NP_001214, NP_150637, NP_150634, NP_150649, NP_001216, NP_116787, NP_001217, NP_127463, NP_001220, NP_004338, NP_004337, NP_116786, NP_036246, NP_116756, NP_116759, NP_001221, NP_203519, NP_001073594, NP_001219, NP_001073593, NP_203520, NP_203522

Use BioMart in Ensembl to generate a list that shows to which Ensembl gene IDs and to which gene names these RefSeq IDs correspond. Do these 29 transcripts correspond to 29 genes?

  1. Go to BioMart. You can find a shortcut to the tool on any Ensembl page in the navigation bar at the top of the page. Click New in the top left-hand menu if you need to start a new query. Choose the Ensembl Genes database. Choose the Human genes dataset.

  2. Click on Filters in the left panel. Expand the GENE section. Select Input external references ID list - RefSeq peptide ID(s) and enter the list of IDs in the text box (either comma separated or as a list).

HINT: You may have to scroll down the menu to see these.

Count shows 10 genes (remember one gene may have multiple splice variants coding for different proteins, that is the reason why these 29 proteins do not correspond to 29 genes).

  1. Click on Attributes in the left panel. Select the Features attributes page. Expand the External section. Select HGNC symbol and RefSeq Peptide ID from the External References section.

  2. Click the Results button on the toolbar. Select View: All rows as HTML or export all results to a file.

Get genes by protein domain

Go to Ensembl Plants and find the following information:

Retrieve the protein sequences (in FASTA format) of all Triticum aestivum (wheat) genes that have an NCBI Gene ID, that are protein-coding and with Transmembrane helices. Do a count after the selection of each filter to check the number of genes remaining in your dataset. Export the results of the sequences and select Gene description and Source of gene name as headers.

  1. Click on BioMart on the navigation bar at the top of the page. Click the New button on the toolbar on the top left-hand corner, choose the Ensembl Plants Genes database and Triticum aestivum genes (IWGSC) dataset. Now, filter for the genes with NCBI Gene ID only:

  2. Click on Filters in the left panel, expand the GENE section by clicking on the + box. Select with NCBI Gene ID under Limit to genes (external references)…. Make sure the box next to the filter is ticked, otherwise the filter won’t work. Click the Count button on the toolbar.

    This will give you 92 Genes.

    Now filter further for genes that are protein-coding by selecting Gene type – protein_coding and click again on Count.

    This still gives you 92 Genes, meaning that all genes you have previously filtered are protein-coding.

    Finally, filter for genes that have a signal peptide domains. Expand the PROTEIN DOMAINS AND FAMILIES section by clicking on the + box. Select Transmembrane helices – Only under Limit to genes….

    There are 79 genes on the bread wheat genome that contain NCBI Gene IDs and protein coding with signal domains.

  3. Go to Attributes on the left-hand panel. Select Sequences from the options on the right. Expand the SEQUENCES section by clicking on the + box and select Peptide. Select the appropriate header information from the HEADER INFORMATION section: Gene description and Source of gene name.

  4. Click on Results on the toolbar and the sequence will be shown as FASTA format. You can export the sequence by downloading it directly to your local machine or sending it to your email.

Mapping Uniprot IDs in Ensembl Plants

BioMart is a very handy tool when you want to map between different databases. The following is a list of IDs from the UniProtKB/Swiss-Prot database of Arabidopsis thaliana proteins that are supposedly involved in flavonoid metabolism: P42813, Q9LS08, Q9ZST4, Q9SYM2, P51102, Q9LPV9, Q9FE25, Q96323, Q9FKW3, P13114, P41088, Q9S818, Q96330, O22203, Q39224, O22264, Q9SD85, Q9LYT3, Q9FJA2, Q43128, P43254, O04153, Q43125, Q9S9P6, Q94C57, Q9LNE6, Q9FK25, Q9SYM5, Q9ZQ95

Using BioMart in Ensembl Plants a list that shows to which Ensembl Gene IDs these UniProtKB/Swiss-Prot IDs map. Also include the gene name and description.

  1. Go to BioMart in Ensembl Plants. Click the New button on the toolbar in the top left-hand corner to start a new query. Choose the Ensembl Plants Genes database. Choose the Arabidopsis thaliana genes dataset.

  2. Click on Filters in the left panel. Expand the GENE section. Select ID list limit – UniProt/Swissprot ID(s). Enter the list of IDs in the text box (either comma separated or as a list).

  3. Click on Attributes in the left panel. Expand the GENE section. Deselect Transcript Stable ID. Select Gene name and Gene description. Expand the EXTERNAL section. Select UniProtKB/SwissProt ID(s).

  4. Click the Results button on the toolbar. Select View: All rows as HTML or export all results to a file. Tick the box Unique results only.

    Your results should show 28 / 32833 genes.

Ensembl Fungi: variation data in the Saccharomyces cerevisiae mitochondrial genome

In Ensembl Fungi, retrieve the variation ID, chromosome name, position in bp and alleles for all sequence variants in the mtDNA. Export the results as an XLS table and have the results sent to you by email.

Go to BioMart. You can find a shortcut on the navigation bar at the top of any Ensembl Fungi page.

  1. Choose your dataset: select Variation and then Saccharomyces cerevisiae short variants from the drop-down menus.

  2. Open Filters in the left-hand panel, expand REGION then select Chromosome/scaffold: Mito.

  3. Open Attributes in the left-hand panel, expand VARIANT ASSOCIATED INFORMATION, then select Variant Alleles in addition to the pre-selected attributes.

  4. Hit Results in the top left-hand corner to see a preview table. At the top of the results page, select Export all results to, choose Compressed web file (notify by email) then choose xls as the file type. Input your email address then hit Go. You will receive your results by email.

Ensembl Protists: exporting homologues with BioMart

Go to Ensembl Protists. For a list of , export the Find Leishmania major orthologues for these Trypanosoma brucei genes: Tb927.3.3470, Tb927.3.3520, Tb11.01.7770, Tb927.8.5110, Tb927.1.1420

  1. Go to BioMart, select the Ensembl Protists Genes database and choose the Trypanosoma brucei genes dataset.

  2. Click on Filters in the left panel. Expand the GENE section. Enter the gene list in the Input external references ID list box. Gene stable ID(s) should be preselected.

  3. Click on Attributes in the left panel. Select the Homologues attributes at the top of the page. Expand the GENE section. Deselect Gene stable ID version, Transcript stable ID and Transcript stable ID version. Expand the ORTHOLOGUES [K-O] section and select Leishmania major Gene ID.

  4. Click Results. Select View: All rows as HTML to open the entire table in a new tab. If you prefer, you can also export as a CSV, TSV or XLS file by using the Export all results to option.