The way sheep Dolly cloned.
These monkeys, whose names are Zhong Zhong and Hua Hua, were born eight and six weeks ago, respectively.
The Chinese team managed to make small changes in this advanced SCNT method and finally work for the primates. But it was not easy to do.
Qiang Sun, senior writer of the study, says: "We have tried a few different methods, but only one has worked. We have had a lot of failures until we find a successful monkey cloning method. "The embryo division method is done by dividing the embryo as the name suggests. Naturally the only single twin at the bottom is formed in this way. This method is often used in assisted reproduction in farm animals. However, no more than four siblings (four) genetically identical can be created.
Conversely, to clone using SCNT, you need to replace what an egg cell attracts with a somatic cell nucleus. This somatic cell nucleus contains the DNA of another individual. This technology has become quite accessible since Dolly. Chinese researchers even made robots that helped clone pigs.
Although SCNT can produce more numbers than identical genetically identical animals according to the embryo division method, it has been tried to clone cheeked monkeys with this method beforehand, and the embryos have shown a tendency not to reach the fertilization stage.
The Chinese team led the previous study to show that preventing epigenetic changes in DNA (chemical changes affecting how certain sequences are expressed) increased the likelihood of survival of other cloned embryos.
Genetically identical ape populations will be an important area of research.