Scientists Made a Mouse Embryos That’s 4% Human– the Highest Level of Human Cells in an Animal Yet

May 25, 2020

(CNN) – Scientists have created a mouse embryo that’s part human — 4% to be exact. The hybrid is what scientists call a human-animal chimera, a single organism that’s made up of two different sets of cells — in this case, a mouse embryo that has both mouse cells and human cells. This human-mouse chimera has by far the highest number of human cells ever recorded in an animal, according to researchers. Their experiment suggests that many types of human cells can be generated in mouse embryos, and at a much faster rate than in human embryos.