RACE TO CLONE SCOTS PANDAS
Dolly the sheep scientists lead world attempt to save species – with DNA taken from Sunshine and Sweetie
SCIENTISTS have taken a dramatic first step towards cloning Scotland’s pair of giant pandas.
Tian Tian and Yang Guang, the pandas at Edinburgh Zoo, have failed to mate despite several attempts to encourage them to have cubs naturally.
Now a team of international scientists – including the embryologist who helped create the world’s first cloned mammal, Dolly the sheep – has conducted pioneering research that paves the way for the animals to be cloned.
The scientists took tissue samples from the bears’ mouths, then managed for the first time to isolate the ‘building-block’ cells which are the vital first stage of the cloning process.
Last night, Roslin Embryology director Dr Bill Ritchie, who is involved with the groundbreaking project, said the breakthrough was ‘the first step’ to cloning the endangered animals. He added: ‘This is a step in bringing back an endangered species or helping to preserve them.’
The discovery is a potential game-changer for conservationists attempting to revive giant panda numbers and could transform the fate of the popular animal.
Tian Tian and Yang Guang, known as Sweetie and Sunshine in Britain, are the only giant pandas in the UK and since their arrival in 2011 there have been high hopes that the
From Page One pair will produce cubs. But female pandas are fertile only once a year and so far attempts by zookeepers to encourage them to mate have failed.
This year, Tian Tian was artificially inseminated, but lost the cub during pregnancy. Now the possibility of cloning is being investigated by experts from the Royal Zoological Society of Scotland, Roslin Embryology, the School of Biological and Biomedical Sciences at Durham University and the China Conservation and Research Centre For The Giant Panda.
They have now updated the scientific community on their progress in the international journal PLOS One, revealing that cell samples were taken from ‘surplus’ tissue from biopsies performed on the pandas during checks to assess their genetic health.
Zoo staff first anaesthetised the animals with dart guns before performing the biopsies by taking samples from the ‘buccal mucosa’ or lining of the cheeks, an area which is quick to heal – a quality that can be exploited in cloning.
From the cheek tissue the scientists isolated ‘multipotent progenitor cells’, a type of building-block stem cell that can transform into other tissues.
Crucially, they could transform these cells, under variable conditions, into the different types used by the body to create the central nervous system, connective tissue, bone and fat. The discovery that such versatile cells exist in the cheeks of pandas could pave the way for cloning the animals. This is crucial because finding suitable cells for cloning in animals is extremely difficult – and compounded when the species is so rare.
But there are many more questions to be answered before scientists attempt to begin the cloning process by injecting the extracted stem cells into unfertilised eggs, then implanting the eggs into a surrogate mother.
Conservationists are unlikely to allow any of the world’s existing giant pandas to be used in reproductive experiments, which means the egg of another related species, such as a black bear or grizzly bear, might have to be used as a host mother for a live cloned panda cub.
The two pandas in Scotland remain the property of the Chinese government and are only ‘rented’ by Edinburgh Zoo. If scientists do manage to clone a panda, the clones will still belong to China.
Meanwhile, more research is required to gain a better understanding of the properties of multipotent progenitor cells.
Dr Ritchie, a former Roslin Institute embryologist who helped create Dolly the sheep, said: ‘The idea was whether we could actually get some cells from the pandas; could we grow them and actually get things started? The fact that you can grow cells is actually a step on the way. The fact you have got them to grow and do various things means they may be a source in the future for a cloning project.
‘People are wary about cloning and would rather go with the conventional methods of reproduction, but pandas are strange animals, a bit of an anomaly because of their lifestyle.
‘This is a step in bringing back an endangered species or helping to preserve them in some way. This is the first step.’
Reproductive cloning, the process of producing offspring using cells from an existing animal, has a huge failure rate and also poses ethical concerns. But some scientists believe it could be a way to ensure endangered wildlife species do not become extinct. There are only 1,864 giant pandas alive in the wild and fewer than 300 in captivity.
The research scientists’ report states: ‘Since the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest.
‘However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process and the dearth of usable tissues from these rare animals.’
The team also attempted to cultivate the cells from the abdominal skin of two other species of animals, a red panda and an Asiatic lion that had been put down on welfare grounds, but these attempts were unsuccessful.
Since Dolly’s birth in 1996, a number of other species have also been cloned, including mice, cows and goats. Now interest is growing in using the technology to preserve species at risk of extinction.
Last night Dr Iain Valentine, director of the Giant Panda Project at Edinburgh Zoo, said the zoo itself had no plans to clone the pandas but that it would be up to scientists in the future to carry out ways of conserving the species using the stored genetic material.
He added: ‘This work is part and parcel of why the pandas are in Edinburgh, where we have lots of great scientists. It’s important to have another way of conserving the species.’