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| Breakthrough in primate cloning | Breakthrough in primate cloning |
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| Experts have for the first time created cloned embryos from adult monkeys - a technical breakthrough that could bring efficient human cloning a step closer. | Experts have for the first time created cloned embryos from adult monkeys - a technical breakthrough that could bring efficient human cloning a step closer. |
| A team in the US created dozens of cloned embryos from a 10-year-old male macaque, the journal Nature reports. | |
| This could make it easier to clone human embryos for use in research. | This could make it easier to clone human embryos for use in research. |
| And the approach might one day lead to treatments for diseases like diabetes and spinal cord injury, without fear of rejection by a patient's body. | |
| The American group was able to extract stem cells from some of the cloned monkey embryos, persuading them to develop into mature heart and nerve cells in the laboratory. | |
| Other scientists have welcomed news of the advance. Robin Lovell-Badge, a UK stem cell scientist at the National Institute for Medical Research in Mill Hill, near London, said: "Although this work has not been published yet, it is potentially significant. | |
| "There has been a worry that primates may prove to be difficult in terms of cloning." | "There has been a worry that primates may prove to be difficult in terms of cloning." |
| Medical promise | Medical promise |
| This would have been a huge setback for researchers working to develop new medical therapies based on embryonic stem cells. | |
| In cloning to obtain stem cells, DNA from an adult animal is inserted into an unfertilized egg that has had its own genetic material removed. The egg is then encouraged to grow into an early embryo, from which stem cells can be extracted. | |
| STEM CELLS Stem cells are master cells, obtained from early-stage human embryos, with potential to develop into any of the body's tissue typesThere are different types, but scientists believe the most useful stem cells come from the tissue of embryosThe copy pre-embryo created for therapeutic cloning is destroyed in the process These stem cells, and the tissue that develops from them, will be a genetic match to the source of the DNA. In this case, the male macaque monkey. | |
| Because stem cells can are the forerunners of all tissues in the body, scientists hope they might one day be able to use these progenitors to create transplant tissue that is genetically matched to patients with degenerative conditions such as diabetes without the fear of rejection by the body. | |
| Human cloning has been dogged by technical difficulties and controversies over faked research. | |
| In 2004, a South Korean team announced that it had created the first cloned human embryos and extracted stem cells from them. But the study was later retracted when it emerged the lead author Dr Hwang Woo-suk had fabricated his work. | |
| The only other published example of a human embryonic clone was created at Newcastle University. But the clones survived for only a few days and did not produce any stem cells. | The only other published example of a human embryonic clone was created at Newcastle University. But the clones survived for only a few days and did not produce any stem cells. |
| Human cloning clues | Human cloning clues |
| The technique used to generate the cloned macaque embryos is called somatic cell nuclear transfer (SCNT). This is the same basic procedure used to create Dolly the sheep and other cloned mammals. | The technique used to generate the cloned macaque embryos is called somatic cell nuclear transfer (SCNT). This is the same basic procedure used to create Dolly the sheep and other cloned mammals. |
| But lead author of the latest study, Dr Shoukhrat Mitalipov, has pioneered a novel way of handling the donor eggs during the cloning process. This technique does not use ultraviolet light or dyes, which appear to damage primate eggs. | |
| The macaque monkey is a standard animal in laboratory workIn a statement, Professor Alison Murdoch and Dr Mary Herbert, of the North-East England Stem Cell Institute (NESCI), said the work "provides the first convincing evidence that nuclear reprogramming is feasible in primates". | |
| They added: "This is a very exciting development which takes us several steps closer to the production of patient-specific stem cells to treat life-limiting conditions such as Parkinson's, motor neurone disease, Huntington's disease and cystic fibrosis. | |
| "By providing proof of principle in a primate model, Dr Mitalipov and his colleagues have made an important step towards realising the therapeutic potential of nuclear transfer in humans." | "By providing proof of principle in a primate model, Dr Mitalipov and his colleagues have made an important step towards realising the therapeutic potential of nuclear transfer in humans." |
| The scientists behind the latest work reportedly tried to implant about 100 cloned embryos into the wombs of around 50 surrogate female macaques. However, their efforts did not result in the birth of any offspring. | The scientists behind the latest work reportedly tried to implant about 100 cloned embryos into the wombs of around 50 surrogate female macaques. However, their efforts did not result in the birth of any offspring. |
| But one author of the study said this could be down to bad luck. For example, Dolly the sheep - the first clone of an adult mammal - was only created after 277 attempts. | But one author of the study said this could be down to bad luck. For example, Dolly the sheep - the first clone of an adult mammal - was only created after 277 attempts. |