Abstract
Cleft lip with palate (CLP) is a common human birth defect with a complex unknown genetic cause. The "A" mouse has been used as an animal model for understanding the molecular pathogenesis of CLP. Our previous study performed genetic crosses using the A/WySn and C 3 H/He strains of mice. It was suggested that CLP due to cortisone exposure was recessively influenced by autosomal genetic factors. The purpose of the present study was to identify the candidate chromosome causing CLP in the A/WySn mice. We examined the individual genotype of 37 N2 backcross embryos with CLP using 82 polymorphic markers that were distributed throughout the autosomal chromosome. The genotypes of all 37 N2 backcross embryos with CLP were A (A, A/WySn) homozygous at D 11 Mit 10 [genotype ratio of A homozygous: A/C 3 H (C 3 H, C 3 H/He) heterozygous was 37: 0, X2>33.11, p< 0.00001], a highly significant linkage was obtained for chromosome 11. High linkage was also obtained at D 14 Mit 34 for chromosome 14 (genotype ratio of A homozygous: A/C 3 H heterozygous was 29: 8, X2=11.92, p< 0.001). These results suggest that the genetic candidate for CLP by cortisone exposure may involve on chromosome 11 and chromosome 14 in the A/WySn mice.
