Tuesday, November 4, 2008

Of Mice And Mammoths: Cloning after Death

Extinct is such a final word. It implies that, what ever the subject is, it's never going to come back. We will never see it again in it's natural habitat outside of Natural History museums, and we've come to accept that. While this may have been true a few years back, in today's society we don't like to think in terms of endings. We like to think in beginnings. 

In the lab of Teruhiko Wakayama, a Japanese geneticist, a mouse was frozen for 16 years, devoid of any cryo-protection, at -20 degrees Celsius. That's -4 degrees Fahrenheit, about the temperature of permafrost located on the upper boundary of the Arctic Shelf, which ranges from 0 to -2 degrees.

At this temperature it seemed impossible to harvest usable nuclei for cloning purposes. They assumed that all of the cells were dead, but with a newly developed cloning process, Wakayama's team was able to extract usable nuclei from the mice's neurons. These were then inserted into the embryos of healthy, living mice. The stem cells produced were then used to make healthy mice pups. Prior to this the record for frozen cells to still be eligible to cloning was only 350 days.

If it was possible to clone a 16 year old frozen mouse, couldn't the same process be used to clone a mammoth frozen in the Siberian Tundra? No tests have been done yet, but the idea if being tossed around to use this method on already extinct species. 

As with prior cloning experiments, the question of ethics comes up, but these are a little different. Technically, after being frozen that long the animal is long dead. By harvesting it's cells, not only are you playing God, but you're playing Frankenstein. It's still reanimating a dead animal, since the one created is genetically identical to the previously frozen mouse. We have to ask our selves if it's morally right to bring back what's dead, and will this be implemented on humans of social significance? The possibilities are endless, but so are the consequences. 



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