Turtle genome offers clues to longevity, surviving without oxygen

Scientists have for the first time decoded the genome of a turtle, unlocking clues to their longevity and ability to survive without oxygen, an attribute that could someday be used to help humans.

The research team included scientists from Washington University School of Medicine and St. Louis University as well as the University of California at Los Angeles. Their analysis is available online in the journal Genome Biology.

In science, turtles are a bit of an enigma. Their distinctive body design with a sharp beak instead of teeth and protective hard shell has changed very little over the past 210 million years. They can live up to four months with no oxygen while hibernating in ice-covered ponds. And while most small animals have short lifespans, a box turtle roaming your backyard can live more than 100 years.

They may be slowly evolving, but turtles have developed an array of enviable features, said senior author Richard Wilson, director of Washington Universitys Genome Institute. They resist growing old, can reproduce even at advanced ages, and their bodies can freeze solid, thaw and survive without damaging delicate organs and tissues. We can learn a lot from them.

Researchers sequenced the genome of the western painted turtle, which lives in freshwater ponds and streams and is the most widespread turtle in North America. What they found was that the creatures unique physiological adaptations are not from novel genes; but from activating genes common to most vertebrates, including humans.

This is a back-door route for turtles to evolve, said co-author Patrick Minx at he genome institute. Rather than evolve new genes, they adapted existing genes for new uses.

The scientists identified 19 genes in the brain and 23 in the heart that are activated in low-oxygen conditions, including one gene that increased nearly 130-fold. These genes are also present in humans and could be important in treatments to protect the heart and brain from oxygen deprivation during a heart attack or stroke.

Their study also showed just how slowly turtles evolve about one-third the rate of humans and one-fifth the rate of the fast-evolving python. The sequencing also puts to rest the argument over where turtles fall in the tree of life. Scientists found they are most closely related to crocodiles and birds, and not lizards and snakes.

Scientists will next try to better understand how the genes work together to protect organs during oxygen deprivation. They can also use the genome information to study other traits such as longevity.

How can their tissue and their cells survive so much longer? said co-author Wesley Warren, also at the genome institute. Thats why this genome is important, for scientists to have access to the entire sequence, so we can start understanding these mechanisms.

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Turtle genome offers clues to longevity, surviving without oxygen