The evolution of selfing in Arabidopsis thaliana.
Unlike most of its close relatives, Arabidopsis thaliana is capable of self-pollination. In other members of the mustard family, outcrossing is ensured by the complex self-incompatibility (S) locus,which harbors multiple diverged specificity haplotypes that effectively prevent selfing. We investigated the role of the S locus in the evolution of and transition to selfing in A. thaliana. We found that the S locus of A. thaliana harbored considerable diversity, which is an apparent remnant of polymorphism in the outcrossing ancestor. Thus, the fixation of a single inactivated S-locus allele cannot have been a key step in the transition to selfing. An analysis of the genome-wide pattern of linkage disequilibrium suggests that selfing most likely evolved roughly a million years ago or more.
Tang
Chunlao
C
Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
Toomajian
Christopher
C
Sherman-Broyles
Susan
S
Plagnol
Vincent
V
Guo
Ya-Long
YL
Hu
Tina T
TT
Clark
Richard M
RM
Nasrallah
June B
JB
Weigel
Detlef
D
Nordborg
Magnus
M
D000483:Alleles; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics*; D005075:Biological Evolution; D022202:Chromosomes, Artificial, Bacterial; D017343:Genes, Plant; D040961:Genetic Drift; D006239:Haplotypes; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011494:Protein Kinases / Q000235:genetics*; D011544:Pseudogenes; D012098:Reproduction / Q000502:physiology
D029681:Arabidopsis Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; C522572:S-locus cysteine rich protein, Arabidopsis; D011494:Protein Kinases; C079832:S-receptor kinase