The coalescent with partial selfing and balancing selection: an application of structured coalescent processes

摘要

As a demonstration of a generally applicable technique, a theorem based on separation of time scales in the structured coalescent is used to extend results for the coalescent process with balancing selection to allow partial selfing. The resulting model behaves like the random-mating one, but with different rates of coalescence and recombination. This result has important implications for attempts to locate selectively maintained polymorphisms. Such polymorphisms can in principle be detected through their effect on the pattern of polymorphism in the genomic region surrounding the site under selection, however this is not practically feasible unless the effected region is sufficiently large. An implication of the present results is that the region is expected to be much larger in partially selfing organisms than in outcrossing ones, suggesting that studies attempting to locate selectively maintained polymorphisms should utilize selfing organisms.