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.
Mssq1 (mandible size and shape QTL 1) mapped to mouse Chromosome 1 in association with two mandible measurements. The nearest linked marker to Mssq1 is D1Mit10 (56.6 cM). KK-derived alleles confer increased mandible size at Mssq1 in the combined F2 population (A<y>/a and a/a). Manln1 (48 cM) is a previously identified QTL overlapping with the Mssq1 interval. An interactinglocus was identified on mouse Chromosome 11 near D11Mit212 (50 cM) and is named Mssq20 (mandible size and shape QTL 20). Homozygosity for C57BL/6JJcl-derived alleles at Mssq1 in conjunction with heterozygous alleles at Mssq20 confer significantly decreased mandible size. This interaction reaches statistical significance value of LOD=3.7.