The two macaque monkeys, named Zhong Zhong and Hua Hua after the Mandarin words for the Chinese nation and people, were born after the researchers used an updated version of SCNT (somatic cell nuclear transfer), where DNA from the cell to be cloned is inserted into an egg cell with no DNA.
Sciences, Shanghai, China used improved microscopy techniques in addition to chemically treating the DNA to overcome the hurdles experienced by other groups trying to clone monkeys using SCNT, publishing their results in Cell. Zhong Zhong and Hua Hua are not the first monkeys to be cloned, however.
Unlike Dolly, who was the first animal to be cloned from an adult cell, Zhong Zhong and Hua Hua were cloned from fetalcells, which are considered to be easier to clone than adult cells. The team did conduct cloning experiments using adult monkey cells, resulting in the births of another two monkeys
