Researchers Revive Genome of Extinct Frog

Researchers from Australia have now re-constructed the genome of an extinct frog species that gave birth through its mouth. The genome was completed using a cloning technology to combine a dead nucleus with an egg from another species of frog.

Rheobatrachus silus (gastric-brooding frog), the ancient frog, had a unique way of giving birth. It first swallowed the eggs and kept them in its stomach until they were ready to hatch. The young ones were then given birth via the mouth.

The revival of the genome was carried out by researchers working on the Lazarus Project that is working on a kind of de-extinction program to bring the dead species of frog back to life.

The research team was able to get the nuclei from fossilized tissues of the frog collected in the 1970s and preserved in a deep-freezer.

For the study, researchers used a technique called as somatic cell nuclear transfer. They first collected fresh eggs from a related species of frogs called Great Barred Frog, Mixophyes fasciolatus. Researchers then replaced the egg nuclei with the dead nuclei obtained from the gastric-brooding frog. The cells began to grow like an embryo, although not many eggs lived for more than a few days.

Genetic tests of the embryos confirmed that they had the genetic material of the extinct frog.

"We are watching Lazarus arise from the dead, step by exciting step. We've reactivated dead cells into living ones and revived the extinct frog's genome in the process. Now we have fresh cryo-preserved cells of the extinct frog to use in future cloning experiments," said professor Mike Archer, of the University of New South Wales, in Sydney, the leader of the Lazarus Project team, according to a news release.

He added that the new technique of completing the genome of an extinct frog species holds great promise as a conservation tool for many amphibians of the world that are going extinct. The species that was brought to life in the present study - R. Silus - had vanished from earth in 1979.

Researchers from around the world are discussing the future of extinct species that are being brought back at TEDx DeExtinction event in Washington DC, hosted by Revive and Restore and the National Geographic Society. The Lazarus project was discussed at the event, the news release said.