Fitness selection in human pluripotent stem cells and interspecies chimeras: Implications for human development and regenerative medicine

A small number of pluripotent cells within early embryo gives rise to all in the adult body, including germ cells. Hence, any mutations occurring cell population are at risk being propagated their daughter and could lead congenital defects or embryonic lethality pose a transmitted future generations. The observation that genetic errors relatively common preimplantation embryos, but levels reduce as development progresses, suggests existence mechanisms for clearance aberrant, unfit damaged Although human embryogenesis is largely experimentally inaccessible, stem (PSC) lines can be derived either from inner mass (ICM) blastocyst by reprogramming somatic into an cell-like state. PSCs retain ability differentiate type vitro and, hence, they represent unique powerful tool studying otherwise intractable stages development. advent has also opened up possibility developing regenerative medicine therapies, through PSC differentiation creating interspecies chimeras organ replacement. Here, we discuss emerging evidence selection populations vivo highlight implications understanding this phenomenon medicine.