volution of dominance in sporophytic self-incompatibility systems: I. Genetic load and coevolution of levels of dominance in pollen and pistil - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Evolution - International Journal of Organic Evolution Année : 2009

volution of dominance in sporophytic self-incompatibility systems: I. Genetic load and coevolution of levels of dominance in pollen and pistil

Résumé

Recent theoretical advances have suggested that various forms of balancing selection may promote the evolution of dominance through an increase of the proportion of heterozygote genotypes. We test whether dominance can evolve in the sporophytic selfincompatibility (SSI) system in plants. SSI prevents mating between individuals expressing identical SI phenotypes by recognition of pollen by pistils, which avoids selfing and inbreeding depression. SI phenotypes depend on a complex network of dominance relationships between alleles at the self-incompatibility locus (S-locus). Empirical studies suggest that these relationships are not random, but the exact evolutionary processes shaping these relationships remain unclear.We investigate the expected patterns of dominance under the hypothesis that dominance is a direct target of natural selection.We follow the fate of a mutant allele at the S-locus whose dominance relationships are changed but whose specificity remains unaltered. We show that strict codominance is not evolutionarily stable in SSI, and that inbreeding depression due to deleterious mutations linked or unlinked to the S-locus exerts strong constraints on changes in relative levels of dominance in pollen and pistil. Our results provide a general adaptive explanation for most patterns of dominance relationships empirically observed in natural plant populations.
Fichier non déposé

Dates et versions

hal-00382437 , version 1 (07-05-2009)

Identifiants

  • HAL Id : hal-00382437 , version 1

Citer

V. Llaurens, S. Billiard, Vincent Castric, X. Vekemans. volution of dominance in sporophytic self-incompatibility systems: I. Genetic load and coevolution of levels of dominance in pollen and pistil. Evolution - International Journal of Organic Evolution, 2009, 63, pp.2427-2437. ⟨hal-00382437⟩

Collections

CNRS
28 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More