#32 · Genomics

Modelling selection on weakly deleterious mutations across genomes and viruses

The common thread is explicit, equation-based modelling that links mutation-scale fitness effects to genome- and population-level outcomes. A preprint infers mutation fitness effects under strong genetic linkage, validated on simulated sequences and applied to 10,000 E. coli genomic sites. A second preprint compares molecular-modeling folding energies and substitution models for predicting phiX174 viability from a large G-protein mutant library. A published study proposes that slightly deleterious mutations attenuate HIV-1 severity and can explain the long-term trajectory of virulence evolution in a pathogen that has evolved an intermediate virulence maximising transmission. The organisms differ, so the shared element is methodological rather than taxonomic. What is new is the quantitative treatment of linkage, biophysical stability, and selection on weakly deleterious variants within mechanistic frameworks.