Experiment
Genetic loci associated with sperm quality were mapped using 12 CBXE/EXCB recombinant inbred (RI) strains derived from KE and CBA/Kw parental strains. Male animals were phenotyped at 3-7 months of age for four parameters of sperm quality. Genome scan wasperformed using 187 polymorphic markers. Parental strain KE displays increased testis weight, increased percentage of abnormal sperm head morphology, increased frequency of slightly bent sperm tails, and decreased frequency of broken sperm tails comparedto parental strain CBA/Kw.
Linkage to abnormal sperm head morphology mapped to mouse Chromosome 11 between D11Mit310 (24 cM, 54 Mb) and D11Mit242 (31 cM, 69 Mb) with LRS=19.5. This locus is named Spqq1 (sperm quality QTL 1). Potential candidate genes mapping near Sppq1 include Kif3a (29.5 cM), Sparc (29.9 cM), Tekt3, Hist3h2ba, Hist3h2bb, Hist3h2a, and Aurkb (40 cM).
Spqq2 (sperm quality QTL 2) mapped to mouse Chromosome 6 between 34 Mb and 45 Mb. Peak linkage occurs at D6Mit268 (15.6 cM) with LRS=18.9. This locus is linked to abnormal sperm head morphology. Hipk2 and Casp2 (20.5 cM) are potential candidate genes located in this interval.
Body mass in males mapped to mouse Chromosome 18 between 66.9 Mb and 74.9 Mb. This locus is named Mbmq1 (male body mass QTL 1). Peak linkage occurs at D18Mit153 (47 cM) with LRS=24.9. Potential candidate genes mapping to the Mbm1 interval include Lipg, Acaa2 (45 cM), Stard6 (44 cM), Mc4r, and Cidea. Interestingly, Mc4r knockout mice are obese.
Analysis Tools