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Effects of genotype on rates of substitution during experimental evolution
Author(s) -
Wong Alex,
Seguin Kimberley
Publication year - 2015
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/evo.12700
Subject(s) - biology , epistasis , mutation rate , genetics , fixation (population genetics) , genotype , mutation accumulation , mutation , genetic variation , population , molecular evolution , evolutionary biology , genome , gene , demography , sociology
Rates of molecular evolution may vary widely between populations, yet the causes of this variation are still incompletely understood. Genetic differences between populations may make an important contribution to variation in rates of evolution, owing to differences in fitness, population size, mutation rates, or in the distribution of fitness effects (DFEs) of available beneficial mutations. By whole genome sequencing of Escherichia coli populations experimentally evolved in the presence of a quinolone antibiotic, we found that rates of substitution varied by genotype, with evidence for a contribution from a genotype's starting fitness. Subsequent targeted sequencing showed that genotypes with high average substitution rates were more likely to undergo the simultaneous fixation of several mutations, consistent with theoretical models of multiple mutation dynamics. Moreover, patterns of substitution were indicative of epistatic relationships between known resistance mutations.