(Nature) – Scientists have created an infant ‘chimaeric’ monkey by injecting a monkey embryo with stem cells from a genetically distinct donor embryo. The resulting animal is the first live-born chimaeric primate to have a high proportion of cells originating from donor stem cells. The finding, reported today in Cell, opens the door to using chimaeric monkeys, which are more biologically similar to humans than are chimaeric rats and mice, for studying human diseases and developing treatments, says stem-cell biologist Miguel Esteban at the University of Chinese Academy of Sciences in Guangzhou, a co-author of the study. (Read More)