title: Genetic dissection of testis weight in mice: quantitative trait locus analysis using F(2) intercrosses between strains with extreme testis weight, and association study using Y-consomic strains.
abstract: In the present study, dissection of genetic bases of testis weight in mice was performed. Autosomes and the X chromosome were searched using traditional quantitative trait locus (QTL) scans, and the Y chromosome was searched by association studies of Y-consomic strains. QTL analysis was performed in ♀DDD × ♂CBA F(2) mice; the inbred mouse DDD has the heaviest testes, whereas the inbred mouse CBA has the lightest testes. Two significant testis weight QTLs were identified on chromosomes 1 and X. A DDD allele was associated with increased and decreased testis weight at the locus on chromosomes 1 and X, respectively. In the reciprocal cross ♀CBA × ♂DDD F(2) mice, QTL on chromosome 1, and not on chromosome X, had a significant effect on testis weight. The DDD allele at the X-linked locus could not sustain testis weight in combination with the Y chromosome of the CBA strain. The Y chromosome per se had a significant effect on testis weight, i.e., DH-Chr Y(DDD) had significantly heavier testes than DH-Chr Y(CBA). On the basis of the results of Y-chromosome-wide association studies using 17 Y-consomic strains, variations in Uty, Usp9y, and Sry were significantly associated with testis weight. Thus, testis weight is a complex quantitative phenotype controlled by multiple genes on autosomes and sex chromosomes and their interactions.
authors.affiliation: National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. jsuto@affrc.go.jp
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Suto
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D018895:Microsatellite Repeats; D009929:Organ Size / Q000502:physiology*; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology*; D014960:X Chromosome / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics