Viromic Insights into Gut RNA Virus Diversity Among Three Corvid Species.

As viromics advances, the diversity and ecological significance of RNA viruses in global ecosystems are gaining growing recognition. Nevertheless, studies on RNA viruses in wildlife, especially non-model avian species, are still relatively scarce. This study employed viral metagenomics to systematically characterize the gut RNA viromes of three widely distributed corvid species on the Qinghai-Tibet Plateau: the Red-billed chough (Pyrrhocorax pyrrhocorax), Daurian jackdaw (Coloeus dauuricus), and Rook (Corvus frugilegus). These three corvid species are closely associated with human-inhabited areas on the Qinghai-Tibet Plateau and display distinctive scavenging behaviors that may lower their exposure to environmental pathogens while concurrently elevating their risk of viral infection, rendering them key targets for viral surveillance and research into zoonotic disease transmission. The analysis annotated viral communities into 4 phyla and 8 classes, with Pisuviricota and Kitrinoviricota emerging as the predominant phyla in all samples. Alpha diversity analysis indicated no significant differences among groups, while beta diversity showed significant compositional differences. KEGG annotation revealed that enriched functional pathways were mainly concentrated in "Global and overview maps", "Drug resistance: antimicrobial", and "Biosynthesis of other secondary metabolites". Furthermore, 4 antibiotic resistance genes and 13 putative virulence factor genes were identified. Phylogenetic analysis further indicated that several identified viruses have the potential for cross-species transmission, underscoring the pivotal role of wild birds in viral ecosystems and disease spread. This study uncovered multi-faceted features of the gut RNA viromes in the three crow species, spanning structural, functional, and evolutionary dimensions. These results offer novel perspectives on the viromes of wild corvids and their potential contributions to viral emergence and dissemination in the Qinghai-Tibet Plateau ecosystem.