Understanding the mechanisms underlying the origin of new species is a fundamental goal of evolutionary biology. In many organisms, the formation of new species depends upon the development of barriers to reproduction. The proposed research will determine the genetic details underlying reproductive barriers between two species of house mice, Mus musculus and Mus domesticus. Previous experiments have shown reproduction between these species produces sterile hybrid males and that some of the genes causing sterility are on the X chromosome. The primary goal of this study is to identify the specific genes on the X chromosome that result in hybrid male sterility. Laboratory breeding experiments will be used to determine which regions of the X chromosome cause hybrid male sterility. Publicly available genome data will be used to identify genes within these regions that are candidates for male sterility. Genetic variation at these genes will be surveyed in natural populations of house mice to determine if they are involved in reproductive isolation in nature.
Little is known about the genetic basis of reproductive isolation among most species in nature. Thus, the proposed research offers a unique opportunity to determine the genetic basis of speciation in an important model system and will lay the groundwork for the first time identifying specific genes involved in speciation in a mammal.
