Transposable element repression using piRNAs, and its relevance to endogenous viral elements (EVEs) and immunity in insects

Alexandra Cerqueira de Araujo (1) , Elisabeth Huguet (1) , Elisabeth A Herniou (1) , Jean-Michel Drezen (1) , Thibaut Josse (1)

1 IRBI - Institut de recherche sur la biologie de l'insecte UMR7261

The piRNA system controls transposable element (TE) mobility by transcriptional gene silencing and post-transcriptional gene silencing. Dispersed in insect genomes, piRNA clusters contain TE copies, from which they produce piRNAs (specific small RNAs). These piRNAs can both target the nascent transcripts produced by active TE copies and directly repress them by heterochromatinization. They can also target mature transcripts and cleave them following amplification by the socalled 'ping-pong' loop mechanism. Moreover, piRNA clusters contain endogenous viral elements (EVEs), from which they produce piRNAs. The current idea is that these piRNAs could participate in the antiviral response against exogenous viral infection. In this review, we show that among insects, to date, this antiviral response by the piRNA system appears mainly restricted to mosquitoes, but this could be due to the focus of most studies on arboviruses.

Domains: Life Sciences [q-bio]; Animal biology; Invertebrate Zoology; Life Sciences [q-bio]; Immunology; Innate immunity; Life Sciences [q-bio]; Biochemistry, Molecular Biology; Genomics [q-bio.GN]

Alexandra Cerqueira de Araujo, Elisabeth Huguet, Elisabeth A Herniou, Jean-Michel Drezen, Thibaut Josse. Transposable element repression using piRNAs, and its relevance to endogenous viral elements (EVEs) and immunity in insects. Current Opinion in Insect Science, 2022, 50, pp.100876. ⟨10.1016/j.cois.2022.100876⟩. ⟨hal-03867197⟩