Today's Messages

Please join the Biology Department and the Great Lakes Center for the seminar “The genomic basis and molecular mechanisms of speciation,” presented by Dr. Yasir Ahmed-Braimah on Monday, April 27, at 3:00 p.m. in SAMC 151. 

Research Seminar Abstract: The process of speciation is driven by the gradual accumulation of reproductive isolating barriers between diverging lineages. Our lab uses several species in the Drosophila genus to dissect the molecular genetic mechanisms of reproductive incompatibilities between species. In this seminar, I will present our work on the evolution of postmating, prezygotic incompatibilities (gametic incompatibilities). In the Drosophila virilis group, gametic incompatibilities evolve rapidly between closely related species. Previous work revealed rapidly evolving interspecific fertilization defects that result from inadequate sperm use even though sperm transfer appears unperturbed. We use a combination of ‘omic technologies and classical genetics to identify the genetic mechanism of this fertilization barrier and show that several features of the male reproductive proteome diverge rapidly between species. Furthermore, we map the genetic locus underlying the female component and show that the mechanism of the incompatibility is likely based on muscular control of the female reproductive tract and improper maintenance of sperm in storage. Our work shows that subtle interactions between maternal and paternal reproductive proteins are key determinants of postcopulatory reproductive interactions, which are subject to intense postcopulatory sexual selection and may drive rapid speciation.