Mapping and Phenotype information for this QTL, its variants and associated markers
Genetic loci affecting mandible size and shape were mapped using 190 mice from a (C57BL/6JJcl x KK-A<y>/TaJcl)F2 intercross. Of the F2 population, 97 animals had the A<y>/a genotype and 93 animals had the a/a genotype. Thirteen measurements taken from the right mandible and 3 principal components were assessed in experimental animals 6-7 months of age. Parental strain KK-A<y>/TaJcl displays increased values across most of the 13 mandible measurements compared to parental strain C57BL/6JJcl. The A<y> allele increases mandible size in KK animals compared to the a allele. A panel of 100 polymorphic markers was used for linkage analysis.
Significant linkage to principal component 3 (PC3) mapped to two positions on mouse Chromosome 12 in the combined F2 population. Mssq11 (mandible size and shape QTL 11) is located at 13 cM near D12Mit136 (LOD=5.2) and Mssq12 (mandible size and shape QTL 13) is located at 38 cM near D12Mit158. KK-derived alleles at both QTL confer increased PC3 values for mandible size. This locus also displays suggestive linkage to PC3 in the A<y>/a F2 group (LOD=2.5). Gsc (52 cM) is a possible candidate gene for Mssq12.