Cheating death at the dawn of life: Developmental control of apoptotic repression in the preimplantation embryo

► The mammalian embryo is resistant to pro-apoptotic signals early in development. ► Early in development, mitochondria are resistant to depolarization. ► Also, epigenetic modifications make the DNA inaccessible to DNases. ► Subsequently, changes in BCL2 family proteins allow mitochondrial depolarization. ► In addition, loss of epigenetic modifications makes the DNA susceptible to DNases.