Molecular Genetic Study of Dental Caries Susceptibility in Mice

The purpose of this study was to identify the major candidate chromosome influencing susceptibility to dental caries in mice and to detect the region that contains it. Genetic factors affecting dental caries in mice were examined using two inbred strains of mice, C57BL/6J and C3H/HeJ, and these genetic crosses were inoculated with Streptococcus mutans serotype c (1.0 x 109 CFU/mouse). The caries scores for C3H/HeJ and C57BL/6J were 3.1±2.6 and 39.8±12.6 (Mean±S.D.), respectively. The mean caries score of the F1 hybrids was 17.6 ±13.2 (Mean±S.D.) which was in the range 1 to 46. The caries scores of F2 [(C57BL x C3H) x (C57BL x C3H)] mice had an extensive range from 0 to 68. These findings suggested that some genes play roles in caries development.Based on our results with the genetic crosses, we used F2 intercross mice to investigate candidate chromosomal linkages using DNA pooling methods and obtained a valuable linkage on chromosomes 2 and 17. Thus, we concluded that one of the candidate genes controlling the genetic difference for the dental caries promoting ability between C3H/HeJ and C57BL/6J might be located on chromosomes 2 and 17.