Frankenscience has taken a new twist with the first live birth of a “chimeric” monkey.
Scientists from China reported the “long-sought” birth of a male primate containing a high proportion of cells derived from a monkey stem cell line.
Images showing the green fluorescence signals in different body parts of the three-day-old animal.
The contribution of stem cells in different tissue types ranged from 21 percent to 92 percent, according to the Chinese team.
The “chimeric” monkey is composed of cells that originated from two genetically distinct embryos of the same species of monkey, according to research published in the journal Cell.
The process has previously been achieved in rats and mice but, until now, has not been possible in other species, including non-human primates.
Study leader Dr. Zhen Liu, of the Chinese Academy of Sciences (CAS), said: “This is a long-sought goal in the field.
“This research not only has implications for understanding naive pluripotency in other primates, including humans, but it also has relevant practical implications for genetic engineering and species conservation.
“Specifically, this work could help us to generate more precise monkey models for studying neurological diseases as well as for other biomedicine studies.”
The primates used in the study were cynomolgus monkeys, also known as crab-eating or long-tailed macaques.
The Chinese team first established nine stem cell lines using cells removed from seven-day-old blastocyst embryos.
They then placed the cell lines in culture to give them an enhanced ability to differentiate into different cell types.
The team performed several different tests on the cells to confirm that they were pluripotent – having the ability to differentiate into all of the cell types needed to create a live animal.
The stem cells were also labeled with a green fluorescent protein so the scientists could determine which tissues had grown out of the stem cells in any animals that developed and survived.
They finally selected a particular subset of stem cells to inject into monkey embryos that were four or five days old.
The embryos were implanted into female macaques, resulting in 12 pregnancies and six live births.
The analysis confirmed that one monkey that was born alive and one fetus that was miscarried were substantially “chimeric” – containing cells that grew out of the stem cells throughout their bodies. Both were male.
The Chinese team used the green fluorescent protein label to determine which tissues contained cells derived from the injected stem cells.
They also used gene sequencing and other tests to confirm the presence of stem-cell-derived tissue across different organs.
The tissue types they tested that contained the stem-cell-derived cells included the brain, heart, kidney, liver, and gastrointestinal tract.
In the live monkey, the contribution of the stem cells in the different tissue types ranged from 21 percent to 92 percent, with an average of 67 percent across 26 different types of tissue that were tested. The numbers were lower in the monkey fetus.
The Chinese team also confirmed the presence of stem-cell-derived cells in the testes and in cells that eventually develop into sperm cells In both animals.
Corresponding author Dr. Miguel Esteban, of BGI Research and CAS, said: “In this study, we have provided strong evidence that naive monkey pluripotent stem cells possess the capability of differentiating in vivo into all the various tissues composing a monkey body.
“This study deepens our understanding of the developmental potential of pluripotent stem cells in primate species.”
“This work helps us to better understand naive pluripotency in primate cells.”
Co-corresponding author Dr. Qiang Sun, of CAS, added: “In the future, we will try to increase the efficiency of this method for generating chimeric monkeys by optimizing the culture conditions for the stem cells, the cultures for the blastocysts where the stem cells are inserted, or both.”
The Chinese team also plans to further explore the mechanisms that underlie the survival of the embryos in the host animals, which they say will help “improve the efficiency” of chimera generation.
Produced in association with SWNS Talker
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