The first chimera monkey is born, with cells from two embryos


By John

The first chimera monkey was born in China, obtained by combining cells derived from two distinct embryos of the same species. It is the first time that such a result has been achieved in primates, thanks to a technique that in the future could help the conservation of species and the production of more targeted animal models to study many human diseases, including neurological ones.

The authors of the study, led by Zhen Liu of the Chinese Academy of Sciences, announced this in the journal Cell.

The researchers took some stem cells from a cynomolgus macaque embryo on the seventh day of development and put them in culture to obtain nine lines of pluripotent stem cells (i.e. capable of differentiating into all the cell types necessary to create a whole animal).

After a series of tests they chose some of these stem cells, marked them with a fluorescent dye and injected them into other embryos of the same species on the fourth or fifth day of development. The chimera embryos were then implanted into a female macaque, resulting in 12 pregnancies and six live-born pups.

Genetic analyzes confirmed that a macaque born alive and an aborted fetus were in effect chimeras, with cells in various parts of the body that had differentiated from the injected fluorescent stem cells. Their presence has been documented in the heart, brain, kidneys, liver and gastrointestinal tract.

In live puppy tissues, the contribution of labeled stem cells varies from 21% to 92%, with an average value of 67% calculated on the 26 tissues analyzed. Lower numbers were instead detected in the aborted fetus. In both specimens, the presence of cells derived from fluorescent stem cells was confirmed both in the testicles and in the cells that give rise to spermatozoa.