Balancing selection in the wild: testing population genetics theory of self-incompatibility in the rare species Brassica insularis.

ABSTRACT: Self-incompatibility (SI) systems are widespread mechanisms that prevent self-fertilization in angiosperms. They are generally encoded by one genome region containing several multiallelic genes, usually called the S-locus. They involve a recognition step between the pollen and the pistil component and pollen is rejected when it shares alleles with the pistil. The direct consequence is that rare alleles are favored, such that the S-alleles are subject to negative frequency-dependent selection. Several theoretical articles have predicted the specific patterns of polymorphism, compared to neutral loci, expected for such genes under balancing selection. For instance, many more alleles should be maintained and populations should be less differentiated than for neutral loci. However, empirical t

SUBMITTER: Glemin S 

PROVIDER: S-EPMC1456519 | biostudies-literature | 2005 Sep

REPOSITORIES: biostudies-literature