The Natural History of Mutations: Quantifying Mutation Parameters in the Wild with Arabidopsis thaliana Mutation Accumulation Lines

Charles B. Fenster

University of Maryland, USA, cfenster@umd.edu

Mutation is the original source of genetic variation and organismal diversity, yet its precise contribution to evolution remains a fundamental problem in biology. From repeated field assays of survival and reproduction, we quantify the combined effects on fitness of spontaneous mutations in Arabidopsis thaliana, using the mutation accumulation line approach. We demonstrate that the effects are beneficial, deleterious, or neutral depending on the environmental context. We also were able to document specific mutations in some lines, some bearing mutations disrupting known loci, which differ strongly in fitness from the founder or premutation genotype. The effects of mutations varies across environments, for example, a line with a major deletion spanning a transcription factor gene expressed lower fitness than the founder undermost conditions but exceeded the founder’s fitness in one environment. The large contribution of genotype by environment interaction (G X E) to mutation effects on fitness implies spatial and/or temporal variation in selection on new mutations and could contribute to the maintenance of standing genetic variation.

(talk in English)

Recent publications:

Rutter, M., A. Roles, J. Conner, R. Shaw, F. Shaw, K. Schneeberger, S. Ossowski, D. Weigel and C. B. Fenster.  2012. Brief Communication: Fitness of Arabidopsis thaliana mutation accumulation lines whose spontaneous mutations are known. Evolution, 66: 2335- 2339.

Stearns, F. W.G and C. B. Fenster. 2013. Evidence for parallel adaptation to climate from natural populations of Arabidopsis thaliana. Ecology and Evolution, doi: 10.1002/ece3.622.