Researchers have created a hybrid embryo that primarily consists of mouse cells, but has adopted human cells as well. In the embryo image above, the green fluorescence indicates where human cells are packed into the blue fluorescent mouse cells. Researchers have garnered human stem cells, manipulated the stage in which stem cells existed, inserted them into the forming mouse embryo, and then became part of the mouse retina, liver, heart and many other organs. In addition, it was found that 0.1 to 4 percent of the mouse was made of the human cells. Of these human cells, the most abundant were found in the red blood cells of the mouse. Also, a few human stem cells were found on the mouse brain. There were no human stem cells that joined the mouse cells that would form sperm and egg. The most fascinating part of this research is how human stem cells will adapt to the host's rate of growth. Researchers identified human stem cells that matured in only 17 days whereas it would have taken significantly longer in a human host. This stem cell study raises a lot of hope and many possibilities. However, many scientists insist on repeating this study in other laboratories to eliminate some doubts.
Sanders, L. (2020, May 14). New hybrid embryos are the most thorough mixing of humans and mice yet. Retrieved from https://www.sciencenews.org/article/mouse-human-chimera-hybrid-embryos
Z. Hu et al. Transient inhibition of mTOR in human pluripotent stem cells enables robust formation of mouse-human chimeric embryos. Science Advances. Published May 13, 2020. doi: 10.1126/sciadv.aaz0298.