Hypervariable region structure and polymorphism of mtDNA from dental pulp and a family analysis

Abstract

Nucleotide sequences of the hypervariable region in the D-loop of mitochondrial DNA (mtDNA) were analyzed using DNA extracted from 140 old dental pulp samples. These sequences were compared with the sequence reported by Anderson et al. Nucleotide substitution in the HV1 region was identified at 77 positions. A C-to-T transition at position 16223 (C16223T) was most frequently detected (77.9%). Fourteen types of C-stretch sequence patterns were detected and the same sequence as Anderson had the highest frequency (57.9%). In the HV2 region, base transitions were identified at 56 positions. A263G was identified in all samples. Seven types of C-stretch were detected, but none had the same sequence as Anderson. In the HV3 region, base transitions were identified at 21 positions. T489C was most frequently identified (64.3%). Five types of C-stretch were detected, and the same sequence as Anderson accounted for 92.9%. The 140 samples were classified into 128 kinds by the sequence patterns of the HV region. Next, using the blood and oral mucosa epithelium from 23 subjects comprising four generations in a family line, the hereditary relationship of mtDNA was examined. All mtDNA types of the first-generation mother were infallibly inherited by the fourth generation.