Narwhal Genomics

Background

As part of Real Vegan Cheese’s Indiegogo campaign, we jokingly hypothesized about our ability to make cheese out of recombinant Narwhal caseins. Half a decade later, the Narwhal genome was finally published in 2019:

• https://www.cell.com/iscience/pdf/S2589-0042(19)30089-6.pdf

• https://gizmodo.com/narwhals-are-thriving-despite-their-weird-genome-1834475092

Check‌ ‌out‌ ‌Patrik’s‌ ‌presentation‌ ‌May‌ ‌2nd‌ ‌‌On‌ ‌Narwhal‌ ‌Cheese,‌ ‌the‌ ‌Evolution‌ ‌of‌ ‌Whales,‌ ‌and‌ ‌Imaginary‌ ‌Phylogeny‌ ‌of‌ ‌Unicorns‌‌ ‌(‌slides‌,‌ ‌‌meeting‌ ‌notes‌,‌ ‌‌video‌)‌ 

Project Goals

Our original goal was obviously to express and purify narwhal casein proteins, and make narwhal cheese. But while we’re all in pandemic lockdown, we figured we could pursue some interesting and publishable evolutionary genomics projects:

1. Evolution of the casein gene cluster in whales and related mammals

The four casein genes tend to occur within a tight cluster of genes, interspersed with a few non-casein genes. All mammals seem to have at least Beta and Kappa casein, but some mammals seem to have lost Alpha S1 or S2. Let’s investigate how this gene cluster has evolved throughout the whale family and in related land mammals

Approach:

• Locate the casein genes in our species of interest

• Identify the casein gene cluster that contains those genes, up to the next gene upstream and downstream

• Use multiple sequence alignment tools to study how these gene clusters have changed during evolution

• Can we tie any of the major evolutionary changes in the gene cluster to major traits that have been studied during whale evolution

2. Evolution of tooth development genes that may be related to tusk development in Narwhal

The narwhal tusk is a giant asymmetrically overdeveloped tooth. If we’re studying evolutionary genomics in Narwhal anyway, why not see if we can identify which genes may be involved in development of its tusk? (Bonus: did you know the casein genes originally developed from tooth development genes early in the evolution of mammals? There is at least on tooth development gene - ODAM - inside the casein cluster.)

Approach:

• Identify tooth development genes - probably in human or rodents, where this has been studied in most depth

• Identify orthologs and paralogs of those tooth development genes in narwhal, it closest non-tusked relative the beluga whale, and at least one other close relative e.g. porpoises, such as dolphin)

• Identify tooth development genes which seem to have diverged significantly in narwhal, compared to beluga and other whales.

  • Genes in which the protein coding region has changed significantly

  • Genes in which upstream regulatory regions have changed significantly