Surprises in Sea Turtle Genes Could Help Them Adapt to a Rapidly Changing World

Published:16 Feb.2023 Source:University of Massachusetts Amherst

To more precisely catalogue the turtles’ genomes, the international team turned to new technologies including long read sequencing. This has made it possible to sequence genomes from virtually any living species and to do so with far more accuracy than was previously possible. Sequencing of the turtles’ genomes was performed both at Rockefeller University, in the Vertebrate Genome Laboratory and at the Max Planck Institute of Molecular Cell Biology and Genetics. “These advances allowed us to do the equivalent of shelving everything according to the Dewey Decimal System so that we can begin to understand how everything fits together,” says Bentley.

Once Bentley and his co-authors had correctly organized and annotated the genetic data, they started finding surprises. The first is that, though greens and leatherbacks diverged from a common ancestor about 60 million years ago, their genomes are remarkably similar. Similar, but not the same. It turns out that green turtles have evolved more genes dedicated to immunity, suggesting an immune system that is better prepared for new pathogens, as well as more olfactory receptors -- they have better senses of smell. The leatherback genome also shows that they lower genetic diversity and have historically had lower population levels. “This is both a blessing and a curse,” says Komoroske, “because it means that, while leatherbacks are a resilient species, there isn't much genetic diversity for them to evolve to meet the challenges of their rapidly changing environment.”