Genetic variation for postzygotic reproductive isolation between Caenorhabditis briggsae and Caenorhabditis sp. 9.

摘要: The process of speciation is key to the origins biodiversity, and yet Caenorhabditis nematode model system has contributed little this topic. Genetic studies in genus are now feasible, owing crosses between recently discovered sp. 9 well-known C. briggsae producing fertile F(1) hybrid females. We dissected patterns postzygotic reproductive isolation these species by crossing eight isogenic strains reciprocally with six 9. determined that overall robust across genetic backgrounds. However, we also quantified significant heritable variation within each for interspecific incompatibilities total adult progeny, egg-to-adult viability, percentage male progeny. This demonstrates intraspecific incompatibility occurs despite extensive, albeit incomplete, isolation. Therefore, emerging general phenomenon variable not restricted highly interfertile, early-stage incipient species, but applies latest stages process. Furthermore, confirm Haldane's rule demonstrate strongly asymmetric parent-of-origin effects (Darwin's corollary) consistently manifest more extremely when hermaphroditic serves as maternal parent. These findings highlight an understanding genetics