Experimental evolution and the dynamics of genomic mutation rate modifiers

• Published in: Heredity Vol. 113; no. 5; pp. 375 - 380
• Main Authors: Raynes, Y, Sniegowski, P D
• Format: Journal Article
• Language: English
• Published: England Springer Nature B.V 01.11.2014; Nature Publishing Group
• Subjects: Alleles; Escherichia coli - genetics; Evolution, Molecular; Evolutionary biology; Genetics; Genetics, Population; Genomics; Models, Genetic; Mutation; Mutation Rate; Natural populations; Population genetics; Review
• ISSN: 0018-067X; 1365-2540; 1365-2540
• DOI: 10.1038/hdy.2014.49

Because genes that affect mutation rates are themselves subject to mutation, mutation rates can be influenced by natural selection and other evolutionary forces. The population genetics of mutation rate modifier alleles has been a subject of theoretical interest for many decades. Here, we review experimental contributions to our understanding of mutation rate modifier dynamics. Numerous evolution experiments have shown that mutator alleles (modifiers that elevate the genomic mutation rate) can readily rise to high frequencies via genetic hitchhiking in non-recombining microbial populations. Whereas these results certainly provide an explanatory framework for observations of sporadically high mutation rates in pathogenic microbes and in cancer lineages, it is nonetheless true that most natural populations have very low mutation rates. This raises the interesting question of how mutator hitchhiking is suppressed or its phenotypic effect reversed in natural populations. Very little experimental work has addressed this question; with this in mind, we identify some promising areas for future experimental investigation.