Chinese scientists report world’s first live birth of chimeric monkey

A team of Chinese scientists has confirmed the first live birth from a monkey containing a large number of cells derived from a monkey stem cell line. This paves the way for scientists to use chimeric primates to study human diseases.

The experiment showed that monkey stem cells, a cell type that can develop into many different cell types, can efficiently contribute to placental tissue beyond the embryo and germ cells.

The research team from the Center for Excellence in Brain Science and Intelligence Technology and the Guangzhou Institutes of Biomedicine and Health under the Chinese Academy of Sciences (CAS) bred the chimeric monkeys using crab-eating or long-tailed macaques.

They first established nine stem cell lines using cells removed from seven-day-old blastocyst embryos, and then placed the cell lines in culture to give them a better ability to differentiate into different cell types.

The stem cells were labeled with fluorescent protein to allow researchers to determine which tissues had grown from these stem cells in animals that developed and survived, according to the study recently published as a cover story in the journal Cell.

Finally, the team selected some stem cells to inject into early monkey embryos that were four to five days old and implanted them into female surrogate macaques, resulting in four aborted fetuses and six full-term living offspring.

In the living monkeys, the contribution of stem cells in the different tissue types averaged 67 percent across the 26 different tissue types tested.

In addition, a living chimeric monkey showed high stem cell contributions reaching up to 90 percent in some tissues, the study revealed.

Such a chimera using cells from two embryos had previously been demonstrated in rats and mice, but had not yet been realized in other species, including non-human primates.

This new research has practical implications for genetic engineering and species conservation, and could help scientists generate more precise monkey models for studying neurological diseases, said Liu Zhen, a CAS researcher and the paper’s corresponding author.