biostudies-literatureUnknown42(2)Yang YThe study of mutational processes in somatic genomes has gained recent momentum, uncovering a wide array of endogenous and exogenous factors associated with somatic changes. However, the overall landscape of mutational processes in germline mutations across the tree of life and associated evolutionary driving forces are rather unclear. In this study, we analyzed mutational processes in single-stranded RNA (ssRNA) viruses which are known to jump between different hosts with divergent exogenous environments. We found that mutational spectra in different ssRNA viruses differ significantly and are mainly associated with their genetic divergence. Surprisingly, host environments contribute much less significantly to the mutational spectrum, challenging the prevailing view that the exogenous cellMolecular biology and evolutionmsaf009https://www.ebi.ac.uk/biostudies/studies/S-EPMC11796089biostudies-literatureAn Expanding Universe of Mutational Signatures and Its Rapid Evolution in Single-Stranded RNA Viruses.PMC11796089Yang YXu MMa LLiu MZhai WZhang XQu YHuang YSWu FChen TfalseAn Expanding Universe of Mutational Signatures and Its Rapid Evolution in Single-Stranded RNA Viruses.The study of mutational processes in somatic genomes has gained recent momentum, uncovering a wide array of endogenous and exogenous factors associated with somatic changes. However, the overall landscape of mutational processes in germline mutations across the tree of life and associated evolutionary driving forces are rather unclear. In this study, we analyzed mutational processes in single-stranded RNA (ssRNA) viruses which are known to jump between different hosts with divergent exogenous environments. We found that mutational spectra in different ssRNA viruses differ significantly and are mainly associated with their genetic divergence. Surprisingly, host environments contribute much less significantly to the mutational spectrum, challenging the prevailing view that the exogenous cell2025-01-01T00:00:00Z2025 Feb2026-06-02T04:15:16.384Z2025-04-19T21:13:35.99ZS-EPMC117960893982331010.1093/molbev/msaf009