Frog that Gave Birth Through Its Mouth Near Revival

Scientists have revived the genome of an extinct Australian frog that gave birth through its mouth.

The scientists, working as part of the aptly named Lazarus Project, used sophisticated cloning technology to implant a “dead” cell nucleus into a fresh egg from another frog species.

“We are watching Lazarus arise from the dead, step by exciting step,” leader of the Lazarus Project team, Mike Archer of the University of New South Wales, said in a University of New South Wales press release.

“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.”

Before they went extinct in 1983, females of the gastric-brooding frog, Rheobatrachus silus, swallowed their eggs, brooded their young in their stomachs, and then gave birth through their mouths.

The scientific team managed to recover cell nuclei from tissues of the frog that were collected in the 1970s. They kept them for 40 years in a conventional deep freezer.

According to the release:

In repeated experiments over five years, the researchers used a laboratory technique known as somatic cell nuclear transfer. They took fresh donor eggs from the distantly related great barred frog, Mixophyes fasciolatus, inactivated the egg nuclei and replaced them with dead nuclei from the extinct frog. Some of the eggs spontaneously began to divide and grow to early embryo stage – a tiny ball of many living cells. Although none of the embryos survived beyond a few days, genetic tests confirmed that the dividing cells contain the genetic material from the extinct frog.

While the extinct frog hasn’t risen from the dead yet, it’s genome now has, lending hope that this species will one day live again.

“We’re increasingly confident that the hurdles ahead are technological and not biological and that we will succeed,” Archer said. “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.”

He recently spoke publicly about the Lazarus Project and also about his ongoing interest in cloning the extinct Australian thylacine, or Tasmanian tiger, at the TEDx DeExtinction event in Washington, D.C. Researchers from around the world are gathered there to discuss progress and plans to resurrect other extinct animals and plants.

Possible candidate species include the woolly mammoth, dodo, Cuban red macaw and New Zealand’s giant moa.

Read more at Discovery News