title: Disruption of genetic interaction between two autosomal regions and the X chromosome causes reproductive isolation between mouse strains derived from different subspecies.
abstract: Reproductive isolation that initiates speciation is likely caused by incompatibility among multiple loci in organisms belonging to genetically diverging populations. Laboratory C57BL/6J mice, which predominantly originated from Mus musculus domesticus, and a MSM/Ms strain derived from Japanese wild mice (M. m. molossinus, genetically close to M. m. musculus) are reproductively isolated. Their F1 hybrids are fertile, but successive intercrosses result in sterility. A consomic strain, C57BL/6J-ChrX(MSM), which carries the X chromosome of MSM/Ms in the C57BL/6J background, shows male sterility, suggesting a genetic incompatibility of the MSM/Ms X chromosome and other C57BL/6J chromosome(s). In this study, we conducted genomewide linkage analysis and subsequent QTL analysis using the sperm shape anomaly that is the major cause of the sterility of the C57BL/6J-ChrX(MSM) males. These analyses successfully detected significant QTL on chromosomes 1 and 11 that interact with the X chromosome. The introduction of MSM/Ms chromosomes 1 and 11 into the C57BL/6J-ChrX(MSM) background failed to restore the sperm-head shape, but did partially restore fertility. This result suggests that this genetic interaction may play a crucial role in the reproductive isolation between the two strains. A detailed analysis of the male sterility by intracytoplasmic sperm injection and zona-free in vitro fertilization demonstrated that the C57BL/6J-ChrX(MSM) spermatozoa have a defect in penetration through the zona pellucida of eggs.
authors.affiliation: Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Toranomon, Tokyo, Japan 105-0001.
authors.forename: Ayako
authors.initials: A
authors.lastname: Oka
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Aoto
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Totsuka
authors.forename: Riichi
authors.initials: R
authors.lastname: Takahashi
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Ueda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Mita
authors.forename: Noriko
authors.initials: N
authors.lastname: Sakurai-Yamatani
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuriki
authors.forename: Nobuo
authors.initials: N
authors.lastname: Takagi
authors.forename: Kazuo
authors.initials: K
authors.lastname: Moriwaki
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiroishi
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D005307:Fertilization in Vitro; D008040:Genetic Linkage; D005838:Genotype; D006824:Hybridization, Genetic; D007178:Inbreeding; D008297:Male; D051379:Mice / Q000145:classification* / Q000235:genetics; D008810:Mice, Inbred C57BL; D040641:Quantitative Trait Loci; D012098:Reproduction; D013737:Testis / Q000502:physiology*; D014960:X Chromosome; D014998:Y Chromosome / Q000235:genetics