In mosquitoes, arboviruses (arthropod borne viruses) transmission depends on three key steps: infection of the midgut after a blood meal, dissemination to secondary tissues, and ultimately transmission to a new host (Wu et al, 2019). Among these, dissemination remains the least understood stage, as the mechanisms underlying viral escape from the midgut are still largely unknown. Recent discoveries in Drosophila have unveiled the remarkable capacity of a subgroup of LTR retrotransposons to move from somatic tissues to the germline through a mechanism reminiscent of viral cell–cell fusion (Voichek et al., 2025). This process is mediated by sORF2, a short transmembrane protein encoded by the retrotransposon, functionally analogous to the FAST fusogens of non‑enveloped RNA viruses and harboring a predicted N‑terminal glycine myristoylation motif known to promote membrane targeting (Wang et al., 2021). Strikingly, Aedes mosquitoes display the highest diversity of sORF2‑encoding transposable elements (TEs) among insects, with Ae. aegypti alone containing more than 33 sORF2-TE families and 3,308 distinct sORF2 blast hits in its genome.
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