supplementary data for the paper "A Group of Segmented Viruses Evolved from Genome Segmentation and Cross-phylum Level Gene Transfer"

Metatranscriptomics have revolutionized our understanding of RNA virus evolution by revealing increased virus diversities and bridging gaps among known virus clades. However, studying the diversity and evolution of segmented viruses has been challenging due to limited whole genome information and low similarity of novel viral segments. We characterized Fusarium asiaticum vivivirus 1 (FaVvV1), a +ssRNA mycovirus with 10 RNA segments (S1 to S10, encoding VP1 to VP10), in phytopathogenic fungus Fusarium asiaticum. VP1 and VP2 are homologous to replication proteins of martellivirals, while VP3 and VP5 share homology with nuclear inclusion protein a and cylindrical inclusion helicase of potyvirids, respectively. FaVvV1 has a rod-shaped virion and VP8 functions as a structural protein resembling the helical capsid of potyvirids and closterovirids. Conservation and evolution of viviviruses were investigated by mining 23 published datasets, identifying 29 vivivirus-related viruses (vivivirids) with a total of 186 virus segments. VP1–VP3, VP5, and VP8 are conserved hallmark proteins of viviviruses. Phylogenetic and structural analyses suggest vivivirids evolved from multiple genome segmentations, gene/domain duplications, and horizontal gene transfer events from pisuviricots to martellivirals, highlighting the complexity of segmented virus evolution.