Virus World

A method that provides cloned embryos with a healthy placenta could pave the way for more research involving the primates.  For the first time, a cloned rhesus monkey (Macaca mulatta) has lived into adulthood — surviving for more than two years so far. The feat, described today in Nature Communications1, marks the first successful cloning of the species. It was achieved using a slightly different approach from the conventional technique that was used to clone Dolly the sheep and other mammals, including long-tailed macaques (Macaca fascicularis), the first primates to be cloned. By replacing the placenta of the cloned embryo with that of embryos produced by an in vitro fertilization technique, scientists reduced developmental defects that can hinder embryo survival while using fewer embryos and surrogate mothers. The new technique could unlock possibilities for using cloned primates in drug testing and behavioural research. “We could produce a large number of genetically uniform monkeys that can be used for drug-efficacy tests,” says Mu-ming Poo, director of the Institute of Neuroscience in the Chinese Academy of Sciences in Shanghai.