title: Genetic architecture and adaptive significance of the selfing syndrome in Capsella.
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.
authors.affiliation: Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyv. 18D, SE-752 36 Uppsala, Sweden. Tanja.Slotte@ebc.uu.se
authors.forename: Tanja
authors.initials: T
authors.lastname: Slotte
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Hazzouri
authors.forename: David
authors.initials: D
authors.lastname: Stern
authors.forename: Peter
authors.initials: P
authors.lastname: Andolfatto
authors.forename: Stephen I
authors.initials: SI
authors.lastname: Wright
mesh_terms: D005075:Biological Evolution; D029687:Capsella / Q000033:anatomy & histology* / Q000235:genetics* / Q000502:physiology; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology; D005819:Genetic Markers; D005838:Genotype; D006824:Hybridization, Genetic; D058885:Multilocus Sequence Typing; D010641:Phenotype; D054817:Pollination; D016133:Polymerase Chain Reaction; D040641:Quantitative Trait Loci; D012098:Reproduction; D012641:Selection, Genetic; D057945:Self-Fertilization; D060436:Self-Incompatibility in Flowering Plants; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers