View Program - 2022 Population, Evolutionary, and Quantitative Genetics Conference

Mutations are the ultimate source of genetic variation, shaping and fueling evolution. We recently found that mutation rates are lower in gene bodies and essential genes in Arabidopsis thaliana. Analyses of synonymous mutations confirm that cryptic selection in mutation accumulation experiments are unlikely to explain these patterns. Instead, these observations support an emerging mechanistic understanding of epigenome-mediated mutation bias. Our findings, like those of others, suggest that the epigenome functions as a scaffold on which DNA repair processes interact. By leveraging the regulated distribution of particular histone modifications, functionally distinct regions of the genome receive more or less DNA repair, and thus less or more mutation, respectively. Here we examine how this mechanistic view fits in theoretical models of mutational modifiers showing that genetic drift imposes a significant constraint on the evolution of adaptive mutation biases. We also explore the evolutionary origins of adaptive mutation bias by examining natural diversity in specific mechanisms and patterns of mutation across diverse organisms.

Origins and evolution of epigenome-mediated mutation bias