title: Direct Gamete Sequencing Reveals No Evidence for Segregation Distortion in House Mouse Hybrids.
abstract: Understanding the molecular basis of species formation is an important goal in evolutionary genetics, and Dobzhansky-Muller incompatibilities are thought to be a common source of postzygotic reproductive isolation between closely related lineages. However, the evolutionary forces that lead to the accumulation of such incompatibilities between diverging taxa are poorly understood. Segregation distorters are believed to be an important source of Dobzhansky-Muller incompatibilities between hybridizing species of Drosophila as well as hybridizing crop plants, but it remains unclear if these selfish genetic elements contribute to reproductive isolation in other taxa. Here, we collected viable sperm from first-generation hybrid male progeny of Mus musculus castaneus and M. m. domesticus, two subspecies of rodent in the earliest stages of speciation. We then genotyped millions of single nucleotide polymorphisms in these gamete pools and tested for a skew in the frequency of parental alleles across the genome. We show that segregation distorters are not measurable contributors to observed infertility in these hybrid males, despite sufficient statistical power to detect even weak segregation distortion with our novel method. Thus, reduced hybrid male fertility in crosses between these nascent species is attributable to other evolutionary forces.
authors.affiliation: Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Russell
authors.initials: R
authors.lastname: Corbett-Detig
authors.affiliation: Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America; Howard Hughes Medical Institute, Department of Molecular & Cellular Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Emily
authors.initials: E
authors.lastname: Jacobs-Palmer
authors.affiliation: Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hartl
authors.affiliation: Department of Organismic & Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America; Howard Hughes Medical Institute, Department of Molecular & Cellular Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Hopi
authors.initials: H
authors.lastname: Hoekstra
mesh_terms: D000818:Animals; D005854:Germ Cells; D006824:Hybridization, Genetic; D007248:Infertility, Male / Q000235:genetics; D008297:Male; D051379:Mice; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci; D060047:Reproductive Isolation