Scientists Trying to Bring Back Extinct Gastric Brooding Frog

Posted on March 18, 2013

Scientists are trying to bring back a strange, extinct Australian frog that brooded its young in its stomach and gave birth through its mouth. The gastric-brooding frog, Rheobatrachus silus, became extinct in 1983.

The Lazarus Project is a "de-extinction" project aimed at reviving the weird frog. Scientists have kept tissues collected in the 1970s in a conventional deep freezer for the past 40 years. In recent experiments, scientists took fresh donor eggs from the distantly related Great Barred Frog, inactivated the egg nuclei and replaced them with dead nuclei from the extinct frog. Some of the eggs began to grow to early embryo stage, but none survived beyond a few days. However, tests confirmed the dividing cells contained the genetic material of the extinct gastric-brooding frog and scientists are optimistic they will eventually be able to bring back the frog.

Professor Mike Archer, of the University of New South Wales, in Sydney, and leader of the Lazarus Project team, said in a statement, "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. We're increasingly confident that the hurdles ahead are technological and not biological and that we will succeed. Importantly, we've demonstrated already the great promise this technology has as a conservation tool when hundreds of the world's amphibian species are in catastrophic decline."

ANIMALS
FROGS