title: Field measurements of genotype by environment interaction for fitness caused by spontaneous mutations in Arabidopsis thaliana.
abstract: As the ultimate source of genetic diversity, spontaneous mutation is critical to the evolutionary process. The fitness effects of spontaneous mutations are almost always studied under controlled laboratory conditions rather than under the evolutionarily relevant conditions of the field. Of particular interest is the conditionality of new mutations-that is, is a new mutation harmful regardless of the environment in which it is found? In other words, what is the extent of genotype-environment interaction for spontaneous mutations? We studied the fitness effects of 25 generations of accumulated spontaneous mutations in Arabidopsis thaliana in two geographically widely separated field environments, in Michigan and Virginia. At both sites, mean total fitness of mutation accumulation lines exceeded that of the ancestors, contrary to the expected decrease in the mean due to new mutations but in accord with prior work on these MA lines. We observed genotype-environment interactions in the fitness effects of new mutations, such that the effects of mutations in Michigan were a poor predictor of their effects in Virginia and vice versa. In particular, mutational variance for fitness was much larger in Virginia compared to Michigan. This strong genotype-environment interaction would increase the amount of genetic variation maintained by mutation-selection balance.
authors.affiliation: Biology Department, Oberlin College, Oberlin, Ohio, 44074. aroles@oberlin.edu.|Kellogg Biological Station, Michigan State University, East Lansing, Michigan, 48824. aroles@oberlin.edu.|Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824. aroles@oberlin.edu.
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Roles
authors.affiliation: Department of Biology, College of Charleston, Charleston, South Carolina, 29401.|Department of Biology, University of Maryland, College Park, Maryland, 20742.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rutter
authors.affiliation: Department of Integrative Biology, Michigan State University, East Lansing, Michigan, 48824.|Department of Biology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: Dworkin
authors.affiliation: Department of Biology, University of Maryland, College Park, Maryland, 20742.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Fenster
authors.affiliation: Kellogg Biological Station, Michigan State University, East Lansing, Michigan, 48824.|Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824.
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Conner
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D059647:Gene-Environment Interaction; D056084:Genetic Fitness; D014644:Genetic Variation; D005838:Genotype; D000067552:Mutation Accumulation; D012641:Selection, Genetic
keywords: Crossing GEI; mutation accumulation; mutation-selection balance; variance GEI