Geneticists Complete Sea Lamprey Genome Sequencing

March 2, 2013

Brett Smith for redOrbit.com Your Universe Online

According to a report in the journal Nature Genetics, an international team of geneticists has announced the successful sequencing of the sea lamprey genome.

The sea lamprey makes for an interesting genetic case from an evolutionary standpoint, being a jawless vertebrate that diverged from jawed vertebrates millions of years ago.

The sea lamprey is a primitive jawless vertebrate that diverged from other jawed vertebrates early in the vertebrate ancestry, said co-author David McCauley, from Oklahoma University, in a statement. Because of its early divergence from other living vertebrates, the sea lamprey genome can provide insights for understanding how vertebrate genomes have evolved, and the origins of vertebrate character traits.

McCauley explained that vertebrates have multiple copies of many genes in their genome as the result of two whole-genome rounds of genetic duplication.

One outstanding question has been the timing of these duplications in vertebrate history, he said. Results from this project suggest that two rounds of duplication predated the divergence of the ancestral lamprey from modern jawed vertebrates. This result is important for understanding how vertebrate genomes have evolved, and in particular, for understanding if the organization of the genome is common to all vertebrates.

The OU geneticist added that the lampreys unique neural physiology makes for an interesting genomic and evolutionary study.

Most vertebrates contain an insulating layer of cells that surround nerve cells, he said. Cells that wrap around a nerve fiber, or axon, are enriched in a protein known as myelin. The insulating properties of myelin allow signals to be conducted rapidly along the nerve fiber, and the loss of myelin results in numerous neurodegenerative diseases in humans.

McCauley said the neurons within lampreys are unwrapped, suggesting that the insulation is specific to jawed vertebrates.

Excerpt from:
Geneticists Complete Sea Lamprey Genome Sequencing