A complex genetic basis to X-linked hybrid male sterility between two species of house mice.
The X chromosome plays a central role in the evolution of reproductive isolation, but few studies have examined the genetic basis of X-linked incompatibilities during the early stages of speciation. We report the results of a large experiment focused on the reciprocal introgression of the X chromosome between two species of house mice, Mus musculus and M. domesticus. Introgression of the M. musculus X chromosome into a wild-derived M. domesticus genetic background produced male-limited sterility, qualitatively consistent with previous experiments using classic inbred strains to represent M. domesticus. The genetic basis of sterility involved a minimum of four X-linked factors. The phenotypic effects of major sterility QTL were largely additive and resulted in complete sterility when combined. No sterility factors were uncovered on the M. domesticus X chromosome. Overall, these results revealed a complex and asymmetric genetic basis to X-linked hybrid male sterility during the early stages of speciation in mice. Combined with data from previous studies, we identify one relatively narrow interval on the M. musculus X chromosome involved in hybrid male sterility. Only a handful of spermatogenic genes are within this region, including one of the most rapidly evolving genes on the mouse X chromosome.
Good
Jeffrey M
JM
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA.
Dean
Matthew D
MD
Nachman
Michael W
MW
D000818:Animals; D003433:Crosses, Genetic; D005298:Fertility; D050172:Genes, X-Linked; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D005838:Genotype; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D051379:Mice; D008957:Models, Genetic; D010641:Phenotype; D040641:Quantitative Trait Loci; D013045:Species Specificity; D013076:Sperm Count; D013737:Testis / Q000502:physiology; D014960:X Chromosome / Q000378:metabolism