Evolutionary landscape of mosquito viral integrations

摘要: The sequenced genome of the arboviral vector mosquito, Aedes albopictus, is replete with repetitive DNA and it harbors an unusually large number endogenous viral sequences, collectively called Nonretroviral Integrated RNA Virus Sequences (NIRVS). NIRVS are enriched both within protein-coding gene exons PIWI-interacting (piRNA) clusters, where they encode piRNAs. Based on these features, have been proposed to function as novel mosquito antiviral immune factors. However, relative importance contributions different functional elements their mechanisms action remain open questions. We apply analytical approach that intersects computational, evolutionary molecular methods identify most likely affecting immunity. Using this strategy, we show a highly dynamic component Ae. albopictus repeatome, which nevertheless maintains core set seemingly oldest similarity Rhabdoviruses. Population-level polymorphism varies depending whether occur in intergenic regions, piRNA clusters or part exons. from differentially widespread diverse populations but conserved at sequence level. This consistent hypothesis act analogously fragments transposable contribute piRNA-based Among exons, AlbRha52 AlbRha12 hallmarks domestication fixed across populations, stably expressed, polymorphic level fast-evolving genes. Overall results support immunity, potentially through modes action.