GENETIC ARCHITECTURE AND ADAPTIVE SIGNIFICANCE OF THE SELFING SYNDROME IN CAPSELLA

Authors

  • Tanja Slotte,

    1. Department of Evolutionary Biology, Evolutionary Biology Centre (EBC), Uppsala University, Norbyv. 18D, SE-752 36 Uppsala, Sweden
    2. Department of Ecology and Evolutionary Biology, University of Toronto
    3. E-mail: Tanja.Slotte@ebc.uu.se
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  • Khaled M. Hazzouri,

    1. Department of Ecology and Evolutionary Biology, University of Toronto
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  • David Stern,

    1. Department of Ecology and Evolutionary Biology, Princeton University
    2. Howard Hughes Medical Institute, Princeton University
    3. Janelia Farm Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147
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  • Peter Andolfatto,

    1. Department of Ecology and Evolutionary Biology, Princeton University
    2. Lewis-Sigler Institute for Integrative Genomics, Princeton University
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  • Stephen I. Wright

    1. Department of Ecology and Evolutionary Biology, University of Toronto
    2. Centre for the Analysis of Genome Evolution and Function (CAGEF), University of Toronto
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  • These authors contributed equally to this work. [Correction make to the authors' affiliations after online publication March 3, 2012.]

Abstract

The transition from outcrossing to predominant self-fertilization is one of the most common evolutionary transitions in flowering plants. This shift is often accompanied by a suite of changes in floral and reproductive characters termed the selfing syndrome. Here, we characterize the genetic architecture and evolutionary forces underlying evolution of the selfing syndrome in Capsella rubella following its recent divergence from the outcrossing ancestor C. grandiflora. We conduct genotyping by multiplexed shotgun sequencing and map floral and reproductive traits in a large (N= 550) F2 population. Our results suggest that in contrast to previous studies of the selfing syndrome, changes at a few loci, some with major effects, have shaped the evolution of the selfing syndrome in Capsella. The directionality of QTL effects, as well as population genetic patterns of polymorphism and divergence at 318 loci, is consistent with a history of directional selection on the selfing syndrome. Our study is an important step toward characterizing the genetic basis and evolutionary forces underlying the evolution of the selfing syndrome in a genetically accessible model system.

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