Chinese scientists have made an intriguing breakthrough in the world of biomedicine by creating a genetically distinct long-tailed macaque, marked by remarkable green eyes and glowing yellow fingertips, through the fusion of pluripotent stem cells from two fertilized eggs of different genetic makeup.
A Unique Chimera
The macaque stands out as the most mixed or chimeric, a term denoting an organism derived from more than two parents. This unique blend is confirmed by the presence of cells and tissues from two separate stem cell lines in various body parts such as the brain, heart, kidney, liver, gastrointestinal tract, testes, and sperm cells. Staggering differences are seen among 26 tissue types in the contributions of extra donated stem cells, with the numbers ranging from 21% to 92%. The brain displays the highest percentage.
Past and Present
Comparisons with previous studies reveal quite an advancement. Earlier experiments produced liveborn and subsequently terminated monkey chimeric fetuses, wherein the offspring showed only a minimal presence of donor cells, between 0.1 and 4.5 percent. The current chimeric monkey demonstrates significantly higher statistics, albeit its life span was limited to ten days.
Implications and Potential
Such an experiment holds promise to pave the way for more accurate monkey models for researching neurological diseases among other areas of biomedicine. While there are ethical concerns to consider, proponents maintain that the potential benefits of precise models for testing diseases and therapies justify the efforts.
Looking forward, the use of genetically edited donor stem cells could allow for testing certain disease outcomes in monkey models. The accuracy of these models is likely to increase parallel to the contribution of the donor stem cells.
A Brief History of Chimera
Tracing the history of chimeric monkeys, 2012 saw the birth of the first live specimens. However, the donor cells contributing to their tissues were at a significantly low percentage, barely around 4 percent.
The creation of the new chimeric monkey involved injecting pluripotent stem cells (labelled with green fluorescent protein) into week-old monkey blastocyst embryos. This process resulted in six live births, with only one monkey showing stem-cell-derived tissue in various body regions. The process still has some way to go in terms of efficiency, a factor possibly influenced by the methods used for culturing the stem cells or embryos in the laboratory.
Contribution to Stem Cell Research
This groundbreaking research could prove instrumental in helping scientists gain a deeper understanding of the early stages of stem cell differentiation in primates. The study presents compelling evidence that naive monkey pluripotent stem cells have the potential to differentiate into all the various tissues that make up a monkey's body.