Earlier this year, at the Chinese Academy of Science, two macaque monkeys, Zhong Zhong and Hua Hua, became the first two primates to be successfully cloned using somatic cell nuclear transfer. Some might recall that this type of cloning gained its fame in the scientific community with its first successful subject, Dolly the Sheep. Somatic cell nuclear transfer, as its name infers, works by transferring the nucleus from a mature body cell into an egg cell that lacks a nucleus. Thus, the body cell DNA is rewritten by the egg cell, and therefore returns it to its embryonic state. This rewritten embryonic cell, basically becomes a blank slate, so to speak, that can then become any cell in the body.
But why haven’t any organism so genetically close to humans, like the macaques, been successfully cloned like this before? Well according to the Mu-ming Poo, the director of the Institute of Neuroscience at the Chinese Academy of Sciences in Shanghai, the main reason primate cloning has been unsuccessful in the past, was due to a failure to reprogram the somatic DNA by the egg. This failure to reprogram the DNA is believed to be caused by an inability to unwind certain sections of the DNA that are very tightly wrapped around the somatic cells histones. To combat this and produce the successful clones found in this experiment, the researchers added specialized molecules designed to loosened these sections of DNA before its reprograming. This breakthrough in cloning ability, will have significant implications on future disease and drug testing programs, as it could make the monkeys, which are already good genetic analogs to humans, even better test subjects, by removing any influence genetic variation between individuals might have on the trial results.
For the article this information was gathered from use https://www.sciencenews.org/article/baby-macaques-primates-clones-dolly-sheep?mode=topic&context=88&tgt=nr
And for more information on somatic cell nuclear transfer cloning use this link https://www.sciencedaily.com/terms/somatic_cell_nuclear_transfer.htm