Tuesday, May 20, 2008

Extinct Tasmanian tiger gene brought back to life

Scientists said Tuesday they had achieved a world first by bringing back to life a gene from the extinct Tasmanian tiger after implanting it in a mouse.

Researchers from universities in Australia and the United States extracted the gene from a 100-year-old preserved specimen of the doglike marsupial -- correctly known as a thylacine -- and revived it in a mouse embryo.

"This is the first time that DNA from an extinct species has been used to induce a functional response in another living organism," said research leader Andrew Pask of the University of Melbourne.

The last known Tasmanian tiger, which took its name from the Australian island and the stripes on its back, died in captivity in the Hobart Zoo in 1936, having been hunted to extinction in the wild in the early 1900s.

Some thylacine pups and adult tissues were preserved in alcohol, however, and the research team used specimens from the Museum Victoria in Melbourne.

"The research team isolated DNA from 100 year old ethanol fixed specimens," the scientists said in a statement.

"After authenticating this DNA as truly thylacine, it was inserted into mouse embryos and its function examined.

"The thylacine DNA was resurrected, showing a function in the developing mouse cartilage, which will later form the bone."

The results were due to be released in the international scientific journal PLoS ONE later Tuesday.

"This research has enormous potential for many applications including the development of new biomedicines and gaining a better understanding of the biology of extinct animals," said co-researcher Richard Behringer of the University of Texas.

At a time when extinction rates are increasing at an alarming rate the discovery is critical, said senior author Marilyn Renfree of the University of Melbourne.

"For those species that have already become extinct, our method shows that access to their genetic biodiversity may not be completely lost," she said. - theage

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