Fish genome offers insights into evolution of land vertebrate

Washington, April 18 (ANI): Genome sequencing of a historic fish has provided a wealth of information on the genetic changes that accompanied the adaptation from an aquatic environment to land.

The African coelacanth genome was sequenced by the Genome Center at the Broad Institute of MIT and Harvard, and analyzed by an international consortium of experts.

Sequencing the coelacanth genome has been a long-sought goal and a major logistical milestone, said Chris Amemiya, PhD, Director of Molecular Genetics at the Benaroya Research Institute at Virginia Mason (BRI) and Professor of Biology at the University of Washington, who led team.

He and scientists throughout the world have campaigned for sequencing of the fish for over a decade.

"Analysis of changes in the genome during vertebrate adaptation to land has implicated key genes that may have been involved in evolutionary transitions," he said.

These include those regulating immunity, nitrogen excretion and the development of fins, tail, ear, eye, and brain as well as those involved in sensing of odorants. The coelacanth genome will serve as a blueprint for better understanding tetrapod evolution.

"This is just the beginning of many analyses on what the coelacanth can teach us about the emergence of land vertebrates, including humans, and, combined with modern empirical approaches, can lend insights into the mechanisms that have contributed to major evolutionary innovations," asserted Dr. Amemiya.

The coelacanth is critical to study because it is one of only two living lobe-finned fish groups that represent deep and evolutionarily informative lineages with respect to the land vertebrates. The other is the lungfish, which has an enormous genome that currently makes it impractical to sequence.

"For evolutionary biologists the coelacanth is an iconic animal, as familiar as Darwin's finches on the Galapagos," said Toby Bradshaw, PhD, Professor and Chair, Department of Biology, University of Washington.

The study will be published as the cover article in Nature. (ANI)