Allelic Genealogies in Sporophytic Self-Incompatibility Systems in Plants

Corresponding author: Mikkel H. Schierup, Institute of Cell, Animal and Population Biology (ICAPB), University of Edinburgh, Ashworth Laboratory, King’s Bldgs., W. Mains Rd., Edinburgh EH9 3JT, United Kingdom., mikkel.schierup{at}biology.aau.dk (E-mail).

Communicating editor: M. K. UYENOYAMA

Expectations for the time scale and structure of allelic genealogies in finite populations are formed under three models of sporophytic self-incompatibility. The models differ in the dominance interactions among the alleles that determine the self-incompatibility phenotype: In the SSIcod model, alleles act codominantly in both pollen and style, in the SSIdom model, alleles form a dominance hierarchy, and in SSIdomcod, alleles are codominant in the style and show a dominance hierarchy in the pollen. Coalescence times of alleles rarely differ more than threefold from those under gametophytic self-incompatibility, and transspecific polymorphism is therefore expected to be equally common. The previously reported directional turnover process of alleles in the SSIdomcod model results in coalescence times lower and substitution rates higher than those in the other models. The SSIdom model assumes strong asymmetries in allelic action, and the most recessive extant allele is likely to be the most recent common ancestor. Despite these asymmetries, the expected shape of the allele genealogies does not deviate markedly from the shape of a neutral gene genealogy. The application of the results to sequence surveys of alleles, including interspecific comparisons, is discussed.

This article has been cited by other articles:

				J. Vieira, E. Teles, R. A. M. Santos, and C. P. Vieira Recombination at Prunus S-Locus Region SLFL1 Gene Genetics, September 1, 2008; 180(1): 483 - 491. [Abstract] [Full Text] [PDF]

				E. Kamau, B. Charlesworth, and D. Charlesworth Linkage Disequilibrium and Recombination Rate Estimates in the Self-Incompatibility Region of Arabidopsis lyrata Genetics, August 1, 2007; 176(4): 2357 - 2369. [Abstract] [Full Text] [PDF]

				J. Hagenblad, J. Bechsgaard, and D. Charlesworth Linkage Disequilibrium Between Incompatibility Locus Region Genes in the Plant Arabidopsis lyrata Genetics, June 1, 2006; 173(2): 1057 - 1073. [Abstract] [Full Text] [PDF]

				M. H. Schierup, J. S. Bechsgaard, L. H. Nielsen, and F. B. Christiansen Selection at Work in Self-Incompatible Arabidopsis lyrata: Mating Patterns in a Natural Population Genetics, January 1, 2006; 172(1): 477 - 484. [Abstract] [Full Text] [PDF]

				J. M. Cork and M. D. Purugganan High-Diversity Genes in the Arabidopsis Genome Genetics, August 1, 2005; 170(4): 1897 - 1911. [Abstract] [Full Text] [PDF]

				N. L. Prigoda, A. Nassuth, and B. K. Mable Phenotypic and Genotypic Expression of Self-incompatibility Haplotypes in Arabidopsis lyrata Suggests Unique Origin of Alleles in Different Dominance Classes Mol. Biol. Evol., July 1, 2005; 22(7): 1609 - 1620. [Abstract] [Full Text] [PDF]

				N. Takebayashi, E. Newbigin, and M. K. Uyenoyama Maximum-Likelihood Estimation of Rates of Recombination Within Mating-Type Regions Genetics, August 1, 2004; 167(4): 2097 - 2109. [Abstract] [Full Text] [PDF]

				M. H. Schierup, A. M. Mikkelsen, and J. Hein Recombination, Balancing Selection and Phylogenies in MHC and Self-Incompatibility Genes Genetics, December 1, 2001; 159(4): 1833 - 1844. [Abstract] [Full Text] [PDF]

				M. H. Schierup, B. K. Mable, P. Awadalla, and D. Charlesworth Identification and Characterization of a Polymorphic Receptor Kinase Gene Linked to the Self-Incompatibility Locus of Arabidopsis lyrata Genetics, May 1, 2001; 158(1): 387 - 399. [Abstract] [Full Text]

				M. H. Schierup and J. Hein Consequences of Recombination on Traditional Phylogenetic Analysis Genetics, October 1, 2000; 156(2): 879 - 891. [Abstract] [Full Text]

				M. K. Uyenoyama Evolutionary Dynamics of Self-Incompatibility Alleles in Brassica Genetics, September 1, 2000; 156(1): 351 - 359. [Abstract] [Full Text]

				G. May, F. Shaw, H. Badrane, and X. Vekemans The signature of balancing selection: Fungal mating compatibility gene evolution PNAS, August 3, 1999; 96(16): 9172 - 9177. [Abstract] [Full Text] [PDF]

				H. Shiba, M. Iwano, T. Entani, K. Ishimoto, H. Shimosato, F.-S. Che, Y. Satta, A. Ito, Y. Takada, M. Watanabe, et al. The Dominance of Alleles Controlling Self-Incompatibility in Brassica Pollen Is Regulated at the RNA Level PLANT CELL, February 1, 2002; 14(2): 491 - 504. [Abstract] [Full Text] [PDF]