First monkey born with embryonic stem cells from more than one genetic origin

Scientists in China have reported the birth of the first chimeric monkey derived from embryonic stem cell lines.

The experiment is described in Thursday’s issue of the scientific journal Cell and, according to scientists, allows for the creation of more accurate monkey models for studying neurological diseases.

So far, the methodology used has only been tested on rats.

The experiment used Javanese monkeys, also known as long-tailed monkeys and commonly used in biomedical research.

Researchers at the Chinese Academy of Sciences have created nine stem cell lines (cells with the ability to give rise to specialized cells) using cells taken from seven-day-old blastocysts (embryonic cells).

They subsequently placed the cell lines in culture to increase their ability to differentiate into other cells and performed a series of tests to confirm whether they had the ability to differentiate into the cell types needed to create a living animal.

The stem cells were labeled with green fluorescent protein so scientists could determine what tissues grew from them into animals that developed and survived.

Finally, the team selected a specific subset of stem cells to inject into the monkeys’ morulae (four- to five-day-old monkey embryos), which were implanted into adult females, resulting in 12 pregnancies and six live births of the monkeys.

According to the work described in the journal Cell, the live-born monkey and the (spontaneously aborted) fetus were essentially chimeric—they had tissues or groups of cells with different genetic origins.

In both fetal and offspring monkeys, both males, the researchers confirmed through genetic sequencing and fluorescent protein testing that the brain, heart, kidneys, liver and testes contained cells derived from embryonic stem cells.