![]() ![]() Several loci causing BDMIs have been isolated from plant and animal species 3, 5. According to this model, novel alleles at one or more loci become fixed in separated populations, either due to genetic drift or selection, and produce detrimental consequences when combined in hybrid offspring after crossing 2. Such post-zygotic barriers to gene flow often result from the establishment of Bateson–Dobzhansky–Muller incompatibilities (BDMIs) 1, 2, 3, 4. Gene-flow barriers can act at the prezygotic stage, for example, by restricting the temporal overlap of the reproductive periods, or at the post-zygotic stage, by decreasing the fitness of hybrid progeny. Speciation proceeds by the establishment of barriers to gene-flow between different populations, ultimately resulting in reproductive isolation 1. Thus, by maintaining differentiated alleles at high frequencies, balancing selection on ancestral polymorphisms can facilitate establishing gene-flow barriers between derived populations through lineage sorting of the alternative alleles. grandiflora, and were divergently sorted into the derived C. Compatible and incompatible NPR1 haplotypes are maintained by balancing selection in C. rubella, while the incompatible NPR1 allele is frequent in the ancestral C. The incompatible RPP5 allele results from a mutation in C. rubella, and the more distantly related C. Here we show that NPR1 and RPP5 loci cause a genetic incompatibility between the incipient species Capsella grandiflora and C. Many such incompatibilities are polymorphic in plants, implying an important role for genetic drift or balancing selection in their origin and evolution. ![]() In the Bateson–Dobzhansky–Muller model of genetic incompatibilities post-zygotic gene-flow barriers arise by fixation of novel alleles at interacting loci in separated populations. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |