(
2014-02-10)
Hajjar, Connie; Sampuda, Katherine M; Boyd, Lynn
Background: The process of fertilization involves a cell fusion event between the sperm and oocyte. Although
sperm contain mitochondria when they fuse with the oocyte, paternal mitochondrial genomes do not persist in
offspring and, thus, mitochondrial inheritance is maternal in most animals. Recent evidence suggests that paternal
mitochondria may be eliminated via autophagy after fertilization. In C. elegans, sperm-specific organelles called
membraneous organelles (MO) cluster together with paternal mitochondria immediately after fertilization. These
MOs but not the mitochondria become polyubiquitinated and associated with proteasomes. The current model for
the elimination of paternal mitochondria in C. elegans is that ubiquitination of the MOs induces the formation of
autophagosomes which also capture the mitochondria and cause their degradation.