Effects of Genetic Background on Response to Selection in Experimental Populations of Arabidopsis thaliana

Corresponding author: Mark C. Ungerer, North Carolina State University, Raleigh, NC 27695., mcungere{at}unity.ncsu.edu (E-mail)

Communicating editor: J. B. WALSH

The extent to which genetic background can influence allelic fitness is poorly understood, despite having important evolutionary consequences. Using experimental populations of Arabidopsis thaliana and map-based population genetic data, we examined a multigeneration response to selection in populations with differentiated genetic backgrounds. Replicated experimental populations of A. thaliana with genetic backgrounds derived from ecotypes Landsberg and Niederzenz were subjected to strong viability and fertility selection by growing individuals from each population at high density for three generations in a growth chamber. Patterns of genome-wide selection were evaluated by examining deviations from expected frequencies of mapped molecular markers. Estimates of selection coefficients for individual genomic regions ranged from near 0 to 0.685. Genomic regions demonstrating the strongest response to selection most often were selected similarly in both genetic backgrounds. The selection response of several weakly selected regions, however, appeared to be sensitive to genetic background, but only one region showed evidence of positive selection in one background and negative selection in another. These results are most consistent with models of adaptive evolution in which allelic fitnesses are not strongly influenced by genetic background and only infrequently change in sign due to variation at other loci.

This article has been cited by other articles:

				S. Rogers and L Bernatchez The Genetic Architecture of Ecological Speciation and the Association with Signatures of Selection in Natural Lake Whitefish (Coregonus sp. Salmonidae) Species Pairs Mol. Biol. Evol., June 1, 2007; 24(6): 1423 - 1438. [Abstract] [Full Text] [PDF]

				N. C. Kane and L. H. Rieseberg Selective Sweeps Reveal Candidate Genes for Adaptation to Drought and Salt Tolerance in Common Sunflower, Helianthus annuus Genetics, April 1, 2007; 175(4): 1823 - 1834. [Abstract] [Full Text] [PDF]

				A. E. Kwitek, H. J. Jacob, J. E. Baker, M. R. Dwinell, H. V. Forster, A. S. Greene, M. P. Kunert, J. H. Lombard, D. L. Mattson, K. A. Pritchard Jr., et al. BN phenome: detailed characterization of the cardiovascular, renal, and pulmonary systems of the sequenced rat Physiol Genomics, April 13, 2006; 25(2): 303 - 313. [Abstract] [Full Text] [PDF]

				R. L. Malmberg, S. Held, A. Waits, and R. Mauricio Epistasis for Fitness-Related Quantitative Traits in Arabidopsis thaliana Grown in the Field and in the Greenhouse Genetics, December 1, 2005; 171(4): 2013 - 2027. [Abstract] [Full Text] [PDF]

				C. C. Spencer and D. E. L. Promislow Age-Specific Changes in Epistatic Effects on Mortality Rate in Drosophila melanogaster J. Hered., September 1, 2005; 96(5): 513 - 521. [Abstract] [Full Text] [PDF]

				R. C. Fuller, C. F. Baer, and J. Travis How and When Selection Experiments Might Actually be Useful Integr. Comp. Biol., June 1, 2005; 45(3): 391 - 404. [Abstract] [Full Text] [PDF]

				H. S. Callahan Using Artificial Selection to Understand Plastic Plant Phenotypes Integr. Comp. Biol., June 1, 2005; 45(3): 475 - 485. [Abstract] [Full Text] [PDF]