Scientists replicate extinct DNA from a frog’s frozen tissue


Scientific advances continue to amaze in the field of cloning. A group of researchers from Newcastle (UK) and Sydney have managed to “return to life” the genome of a frog, the Rheobatrachus silus, which became extinct in 1983. The achievement was completed through the manipulation of amphibian tissues that were kept frozen since 1970.

The main peculiarity of this amphibian was the method of gestation of offspring. The Rheobatrachus devoured their own fertilized eggs, to  incubate them inside its stomach and gave birth through the mouth.

For five years, the scientists used the same technique performed for cloning Dolly the sheep, the transfer of somatic nuclear cells. To carry it out, the researchers used amphibian eggs of a family close to the disappeared frog, the Mixophyes fasciolatus. They blocked the nucleus of that cell and inoculated the animal that disappeared 30 years ago.

The results surprised the makers themselves who collaborate on an initiative called Project Lazarus. Some of the eggs handled extinct amphibian genome spontaneously began to divide and grow into an embryonic stage. Unfortunately, none of the embryos survived the process. Tests however showed that cells containing genetic material divided into Rheobatrachus silus.

“We revived dead cells, and thus have also revived the extinct frog’s genome. Now we have the frog’s cells cryopreserved for future use in cloning experiments,” said the head of Project Lazarus, Professor Mike Archer.

“We are increasingly confident that the obstacles ahead are not biological but technological” he stressed, adding that “it is important to note that we have shown how this technology promises as a conservation tool in a time when hundreds of species world’s amphibians are threatened with extinction. ”

After the immense achievement Archer’s team believes that the options are almost limitless. The Lazarus Project encouraging successes prompted scientists to think about the recovery of extinct mammals of Australia, the Tasmanian tiger or the mammoth.