Conserved but mechanistically diverse piRNA defence against endogenous retroviruses in insects - PubMed
3 hours ago
- #retrotransposons
- #insect evolution
- #piRNA defense
- The study investigates the conservation and mechanistic diversity of Piwi-interacting RNA (piRNA)-mediated defense against envelope-carrying gypsy LTR retrotransposons across insects.
- Research shows that multiple insect species, including mosquitoes, stingless bees, and crickets, produce piRNAs targeting gypsy elements in ovarian somatic cells, indicating a persistent evolutionary arms race spanning over 400 million years.
- In Aedes aegypti, ovarian somatic cells express the same piRNA clusters used in other somatic tissues to target RNA viruses, suggesting a shared origin between anti-viral and anti-retrotransposon defenses.
- Lineage-specific differences in piRNA biogenesis pathways are observed: slicing-independent phasing dominates in dipterans, ping-pong amplification in bees, and slicing-dependent phasing in crickets.
- The findings imply that distinct piRNA pathways have independently evolved at different times to silence the same class of retrotransposons during insect evolution.