Three monkeys a genetic mishmash

For the first time, scientists have created primates whose cells carry one of several sets of genetic instructions instead of one consistent assemblage of DNA. The three rhesus monkeys are chimeras, conglomerates of cells from up to six genetically different embryos.

The scientists added embryonic stem cells engineered to carry a glowing protein to an early-stage embryo called a blastocyst. The blastocyst is a ball of cells; the outer part becomes the placenta and other supporting tissues, while embryonic stem cells inside give rise to the actual fetus.

To create the chimeric animals, the researchers had to take a step backward from the blastocyst stage to embryos at the four-cell stage of development. The researchers created the chimeric monkeys by fusing together up to six of those four-cell-stage embryos. The three monkeys, named Chimero, Roku (Japanese for six) and Hex (Greek for six), are all normal and healthy, the researchers report.

Because rhesus monkey stem cells behave so much like human embryonic stem cells, researchers think the findings can be extrapolated to human cells. “But it’s possible this is going to be rhesus monkey–specific,” Mitalipov says. To find out, he hopes to make other chimeric primates, possibly starting with marmosets.

Reference:Science News.org