Degradation of paternal mitochondria via mitophagy

In most sexually reproducing organisms, mitochondrial DNA (mtDNA) is inherited maternally. In this review, we summarise recent knowledge on how paternal mitochondria and their mtDNA are selectively eliminated from embryos. Studies based on Caenorhabditis elegans have revealed that paternal mitochondria and their mtDNA are selectively degraded in embryos via mitophagy. Thus, mitophagy functions as the mechanisms of maternal inheritance of mtDNA. The mitophagy of paternal mitochondria is conserved in other species, and the underlying molecular mechanisms have begun to be elucidated. In addition to mitophagy, autophagy-independent digestion of paternal mtDNA before and after fertilization serves as another mechanism for maternal inheritance of mtDNA. Maternal inheritance of mtDNA is strictly controlled via multistep mechanisms. These studies also demonstrate a physiological role of mitophagy during animal development.