VOA标准英语2008年-Australian, US Scientists Bring Extinct Gene Ba(在线收听) |
By Phil Mercer Sydney 21 May 2008 Australian and U.S. scientists have successfully inserted a gene from the extinct Tasmanian tiger into a mouse embryo. They say the result has been bone and cartilage from the extinct marsupial developing inside the embryo. From Sydney, Phil Mercer reports. The last known Tasmanian tiger or thylacine, died in a Zoo in Australia's southern island state in 1936. The dog-sized marsupial carnivore was hunted to extinction early in the last century. The scientists extracted DNA - genetic material - from a 100-year-old specimen that had been preserved in a museum, and injected it into a mouse embryo. The nine-year project was the work of a joint research team from universities in Melbourne, Australia, and Texas in the United States. They watched as thylacine bone and cartilage began to grow in the embryo. Turning a museum relic into a living creature is currently not possible and those expecting the cloning of an entire animal from an extinct species are likely to be disappointed. But scientist Andrew Pask from the University of Melbourne says the results could lead to experiments that answer questions about the bodies of other extinct species. "So, any extinct species at all that has some intact DNA left, you can then use this technique to actually examine the function of the genes contained within that genome," Pask explained. "So, there is a lot of DNA available from mammoth and Neanderthal that you could potentially use this technique now to examine exactly how those genes may have functioned." This is the first time that DNA from an extinct species has been used to grow tissue and bone in a living animal. The technique could be used to reactivate individual genes from other long-lost creatures, including dinosaurs. Their genes could be transplanted into living animals to determine, for example, what their skin looked like or whether they were warm or cold blooded. There could also be practical applications for humans. The researchers on this project think their discoveries have the potential to create new cancer-fighting medicines. |
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