Mitochondrial endonuclease G mediates breakdown of paternal mitochondria upon fertilization

Abstract

Eliminating paternal mitochondria During fertilization, the oocyte and sperm each bring their mitochondria to the union. Shortly afterward, the paternal mitochondria are degraded, and only the maternal mitochondria are conveyed to the progeny. Zhou et al. observed that the integrity of the inner membrane of paternal mitochondria is compromised, which apparently marks them for degradation (see the Perspective by van der Bliek). Autophagy commences by mitochondrial endonuclease G relocating from the intermembrane space into the matrix and subsequently degrading the paternal mitochondrial DNA. Any delay in this process increases embryonic lethality. Science , this issue p. 394 ; see also p. 351