title: Genetic dissection of hybrid incompatibilities between Drosophila simulans and D. mauritiana. II. Mapping hybrid male sterility loci on the third chromosome.
abstract: Hybrid male sterility (HMS) is a rapidly evolving mechanism of reproductive isolation in Drosophila. Here we report a genetic analysis of HMS in third-chromosome segments of Drosophila mauritiana that were introgressed into a D. simulans background. Qualitative genetic mapping was used to localize 10 loci on 3R and a quantitative trait locus (QTL) procedure (multiple-interval mapping) was used to identify 19 loci on the entire chromosome. These genetic incompatibilities often show dominance and complex patterns of epistasis. Most of the HMS loci have relatively small effects and generally at least two or three of them are required to produce complete sterility. Only one small region of the third chromosome of D. mauritiana by itself causes a high level of infertility when introgressed into D. simulans. By comparison with previous studies of the X chromosome, we infer that HMS loci are only approximately 40% as dense on this autosome as they are on the X chromosome. These results are consistent with the gradual evolution of hybrid incompatibilities as a by-product of genetic divergence in allopatric populations.
authors.affiliation: DCMB and Department of Zoology, Duke University, Durham, NC 27708, USA. ytao@oeb.harvard.edu
authors.forename: Yun
authors.initials: Y
authors.lastname: Tao
authors.forename: Zhao-Bang
authors.initials: ZB
authors.lastname: Zeng
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Hartl
authors.forename: Cathy C
authors.initials: CC
authors.lastname: Laurie
mesh_terms: D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D015415:Biomarkers; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics*; D003433:Crosses, Genetic; D004330:Drosophila / Q000235:genetics*; D004843:Epistasis, Genetic; D005799:Genes, Dominant; D014644:Genetic Variation; D006824:Hybridization, Genetic; D007248:Infertility, Male / Q000235:genetics*; D008126:Lod Score; D008297:Male; D040641:Quantitative Trait Loci; D011995:Recombination, Genetic; D012737:Sex Factors; D013045:Species Specificity; D014960:X Chromosome; D014998:Y Chromosome
chemical_list: D015415:Biomarkers