Скачать или смотреть It’s the EVE Genes?

After fertilization, the zygote inherits mitochondria almost exclusively from the mother, because paternal mitochondria are actively recognized and destroyed by the cell.
When the sperm enters the egg, it brings a tiny number of mitochondria in its midpiece. However, these paternal mitochondria are tagged for degradation. One main mechanism involves ubiquitination: before or shortly after fertilization, proteins on the surface of the sperm’s mitochondria are marked with ubiquitin molecules, which act as a signal for cellular disposal. Once inside the egg, the zygote’s cellular machinery detects these tags and directs the paternal mitochondria to degradation pathways.
Two key processes are thought to eliminate them:
Autophagy (specifically mitophagy): the sperm-derived mitochondria are engulfed by autophagosomes, then fused with lysosomes where they are broken down.
Proteasomal degradation: in some species, the ubiquitin-proteasome system dismantles sperm mitochondria directly.
This destruction ensures maternal inheritance of mitochondrial DNA (mtDNA). It prevents potential conflicts between two sets of mitochondria, reduces the risk of damaged paternal mtDNA being passed on (since sperm mitochondria undergo high metabolic stress during motility), and maintains evolutionary stability by keeping mitochondrial inheritance uniparental.

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