A live-born baby crab macaque in China is the first monkey to be composed of stem cells from two genetically distinct embryos of the same species, something that had only been achieved in rats and mice. The monkey, which lived 10 days before being euthanized, was created by combining stem cells from a cynomolgus monkey with a genetically distinct embryo from the same monkey species.
According to researchers, this is the first live birth of a primate chimera created with stem cells. A proof-of-concept study detailing the research, published Thursday in the scientific journal Cell, highlights that the monkey was “substantially chimeric” in that it contained a variable but relatively high proportion of cells that grew from stem cells throughout its body.
Zhen Liu, lead author of the research at the Chinese Academy of Sciences, adds: “In particular, this work, from the first monkey, could help us to generate more accurate monkey models for the study of neurological diseases, as well as for other biomedical studies,” he says.
The First Living Chimeric Monkey Created in a Laboratory
The monkeys used in the study were crab macaques, a common primate in biomedical research. The researchers first established nine stem cell lines, using cells taken from 7-day-old embryos. They then placed them in culture to give them a greater ability to differentiate into different cell types for the first monkey.
They also performed a series of tests on the cells to confirm that they were pluripotent, and the stem cells were labeled with a green fluorescent protein so that they could determine which tissues had grown from them in any animal that developed and survived.
Ultimately, they selected a particular subset of stem cells to inject into early embryos that were between 4 and 5 days old. These were implanted into female macaques, resulting in twelve pregnancies and six live births. The analysis confirmed that one live-born monkey and one aborted fetus were substantially chimeric, containing cells that grew from stem cells throughout their bodies. Both males.
Green Tags to Differentiate Tissues in the First Monkey
To determine which tissues contained cells derived from the injected stem cells, the scientists used green tags through fluorescent proteins. They also used gene sequencing and other tests to confirm their presence in different organs of the first monkey.
The tissue types they tested that contained the stem cell-derived cells included the brain, heart, kidneys, liver, and gastrointestinal tract. In the living monkey, the contribution of stem cells in the different tissue types ranged from 21% to 92%, with an average of 67% across the 26 tissue types tested. The figures were lower in the monkey fetus.
In both animals, the presence of stem cell-derived cells was also confirmed in the testes and in the cells that eventually became sperm. The researchers also plan to further explore the mechanisms underlying embryo survival in animal hosts, which they say will help improve the efficiency of chimera generation.
This story was written in Spanish by Perla Vallejo in Ecoosfera
