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The new Ensembl release includes a new view for SNPs and other genomic variations. It shows the alignment of the polymorphic position together with 10 base pairs of sequence up- and downstream. The user can choose among all available multiple alignments. Polymorphic positions in the other species are also shown.

This is very useful for looking at ancestral alleles, especially in combination with our EPO alignments as they include the inferred ancestral sequence. Although dbSNP provide predicted ancestral alleles for human SNPs, these are based on the chimp sequence only. In several cases, the ancestral sequence inferred from the multiple alignment is in disagreement with the chimp sequence like in this example. Using multiple alignments gives better results and more confidence to the calls.

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Many users ask us about how to download data from ensembl. Usually, the answer is using BioMart. Comparative genomics data are also available in the standard Mart for your favorite species. For instance to get all the human-mouse orthologs, one can select the human dataset, filter all the genes with no mouse orthologs and choose to output the mouse orthologs for all the resulting genes.

Here is how to get these data in 10 simple steps
1. Go to: http://www.ensembl.org/biomart/martview
2. Choose “Ensembl 52”
3. Choose “Homo sapiens genes (NCBI36)”
4. Click on “Filters” in the left menu
5. Unfold the “MULTI SPECIES COMPARISONS” box, tick the “Homolog filters” option and choose “Orthologous Mouse Genes” from the drop-down menu.
6. Click on “Attributes” in the left menu
7. Click on “Homologs”
8. Unfold the “MOUSE ORTHOLOGS” box and select the data you want to get (most probably the gene ID and maybe the orthology type as well).
9. Click on the “Results” button (top left)
10. Choose your favorite output

Here is the preview of the results:

Other people may prefer to use our Compara Perl API or get the data directly from the Compara DB. These options are also available.

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(you wouldn’t expect orangutans out of the trees, would you?)

Ensembl 49 will contain good news on the comparative genomics side. Apart from the new whole-genome multiple alignments for which we can now handle segmental duplications and infer ancestral sequences (see Ewan’s post on the 20th of January), two new species will be available, namely horse and orangutan.

We are especially excited about the new orangutan genome as it is a key species in the primate lineage, in between the human, chimp and gorilla group and the Old World monkeys. Its inclusion in our gene trees will result in a better resolution of the phylogeny of the primate genes.