July 31, 2013
Dolly The Sheep Creator Discusses Woolly Mammoth Clone
Lee Rannals for redOrbit.com - Your Universe Online
Ian Wilmut, creator of Dolly the sheep, says that woolly mammoth stem cells may be the way to go in order to bring the ancient behemoths back to life.Wilmut, Emeritus Professor at the MRC Center for Regenerative Medicine at University of Edinburgh, wrote in The Conversation about his thoughts on how we could bring woolly mammoths back from extinction. The professor is best known for cloning Dolly, the first mammal to be cloned from an adult somatic cell.
The scientist wrote that the same methods used to create Dolly would not work for recreating a mammoth. However, he said there are other ways in which it would be "biologically interesting to work with viable mammoth cells if they can be found."
"In order for a Dolly-like clone to be born it is necessary to have females of a closely related species to provide unfertilized eggs, and, if cloned embryos are produced, to carry the pregnancies. Cloning depends on having two cells," Wilmut wrote. "One is an egg recovered from an animal around the time when usually she would be mated."
He said there would need to be several hundred to a thousand eggs to allow an opportunity to optimize the cloning techniques. One suggestion is to use eggs from elephants; but as Wilmut pointed out it is not appropriate to try and obtain 500 eggs from a mammal that is becoming extinct. Instead, he says it could be possible to obtain a few mature elephant eggs and transplant them into mice, which could yield a considerable amount of eggs.
The chances of cells found in mammoths in the frozen Siberian landscape being viable would increase if bones could be recovered from the lowest possible temperature. Wilmut said cells will degenerate rapidly as the temperature lowers to the point that snow and ice melts; so even those at the coldest temperature could become useless as they thaw.
Cells found in warmer temperatures could be gradually warmed up, enabling the nuclei to be transferred directly into eggs.
According to Wilmut, scientists would need to introduce the mammoth nucleus into an egg immediately, by injecting the contents of the damaged cell into the egg. If this results in embryo development, then it would need to be transferred to surrogate mothers to develop through pregnancy. Embryo transfer is carried out in fewer than a dozen species, and the elephant is not one of them.
Wilmut said there is biological uncertainty about the availability of viable cells, and that several complex techniques would need to be developed in order to bring mammoths back.
"There is no guarantee that these techniques are even biologically possible. There may be unknown differences between species that would prevent the procedures that we developed in sheep being successful in mammoths," the scientist wrote.
However, despite the uncertainties of this technique, Ian offered up another method using stem cells.
"They would provide extraordinary opportunities to compare mammoth cells with those of elephants. This knowledge would be of fundamental biological interest. It would enable us to begin to answer groundbreaking questions," Wilmut said.
Stem cells could help scientists determine whether male mammoth sperm could be used to fertilize eggs of an elephant, which could lead to a hybrid animal.
With all the possibilities still open to scientists, Wilmut says it is necessary to consider the welfare of the animal, such as the environment for it to live, as well as setting up social interactions with other elephants, mammoths or hybrids.
"So while unlikely at present, the development of some form of mammoth creature or hybrid might be possible in the longer term, the research of which could lead to major biological discoveries and advances," he concluded. "All in all, research to produce mammoth stem cells would be the appropriate choice, and extraordinarily scientifically rewarding, should it be possible to find viable mammoth cells."