Several ways have been proposed on how it could be done. For example, inseminating an Asian elephant cow with a reconstructed mammoth sperm and subsequent absorptive breeding. A more effective and modern idea is the CRISPR method that is favourised by a number of scientists today. To put it simply, CRISPR is about cutting (splicing) a DNA strand (in this case, an Asian elephant's) at the loci where it differs from the template (mammoth) and to exchange the original base pairs with the ancient ones to create an ever increasingly mammoth-like functional DNA strand.
Renomed geneticist George M. Church and his lab at the Harvard University are involved in a project that tries to genetically reconstruct a mammoth on long-term sight this way. Now they managed to splice ancient mammoth genes into the genome of an Asian elephant and the ancient genes did indeed show normal function in the A. elephant cells. Allegedly these genes are involved in typical mammoth characteristics, such as subcutaneous fat, small ears and hair growth, but I don't know how reliable that claim is. The results have not been published in a peer-reviewed paper yet because there is more work to do, Church says.
Something similar has already been achieved with a gene of the Thylacine responsible for cartilage formation. Go here for the paper.
Does this bring us closer to seeing a living woolly mammoth again? Not necessarily. But at least it has been shown that it is possible to insert some mammoth genes into the genome of an extant elephant and to have them working normally. Of course it will be possible to create a full mammoth genome this way, as long it is fully resolved, but there are still practical issues, such as using a female elephant as a surrogate and perhaps also epigenetics. We have to be patient.
Further read:
http://www.telegraph.co.uk/news/science/science-news/11488404/Woolly-mammoth-could-roam-again-as-extinct-DNA-merged-with-elephant.html
http://www.iflscience.com/plants-and-animals/scientists-successfully-insert-woolly-mammoth-dna-elephant-genome
http://www.popsci.com/woolly-mammoth-dna-brought-life-elephant-cells
http://www.popsci.com/scitech/article/2009-06/shark-factory
For more article on cloning extinct animals, go here:
- Clong as a chance for the Wisent?
- Extinct species/subspecies that could be revived through cloning
- Complete genome of an aurochs sequenced
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ReplyDeleteThere is no reason we couldn't use CRISPR to expedite or assist projects breeding back the aurochs and quaggas. Very exciting technology. I'm also excited for its potential to genetically rescue low diversity animals like wisent.
ReplyDeleteMaybe its less a problem of technology than of interest. Wisent, quagga and aurochs are simply not nearly as popular and sensational as a woolly mammoth would be. I sent my wisent concept to the Long Now foundation, which is probably the most down to earth and most practical idea on restoring or rescuing species using genetics, but recieved no answer because they and also G. Church and his lab are focusing totally on the mammoth for now. What a pity.
DeleteWhat about soon-to-be-extinct species, such as Javan rhinoceros, Sumatran rhinoceros or Javan leopard? They should be both easy to clone and more importantly, there is a place for them in world as it is now, unlike mammoth.
ReplyDeleteOn yeah, the lack of sensational value (though leopard kittens are cute...).
Its indeed a pity that genetic rescuing/reconstruction does not focus on critically endangered species. As to the Sumatran rhinoceros, I don't know if cloning rhinos is that easy. I guess it would be rather expensive, take a long time and is very laborious. F.e. you would have to take blood or tissue samples from all living Java rhinos (which are about 50 and non of them in captivity), let alone the problems of cloning in general.
DeleteIt would be more practical to catch a number of those rhinos, or perhaps all of them, and do an extensive breeding program in the classical way, I think.