Polymorphism and Mutation of C-Stretch of the D-loop of Mitochondrial DNA.

Korean J Leg Med. 2005 May;29(1):33-46. Korean.

Department of Forensic Medicine, Chonnam National University Medical School, Korea. jtpark@chonnam.ac.kr

To investigate the polymorphism and mutation of the C-stretch of the D-loop in mitochondrial DNA in the maternal lineages in Koreans, Amp-FLP (amplified fragment length polymorphism), cloning and sequencing, and analysis of overlapped signals of the end of C-stretch after enlargement of Y axis of electropherogram were performed in 104 random objects and 63 families which are confirmed by STR analysis of autosome, Y chromosome, X chromosome and D-loop of mitochondrial DNA. Analysis of Amp-FLP and enlargement of Y axis of electropherogram are better than sequencing after cloning in the analysis of C-stretch. C- stretch 16183 has 15 genotypes, C-stretch 303 has 14 genotypes, C-stretch 568 has 6 genotypes, These results are useful for individual identification. However, mutation of C-stretch 16183, C-stretch 303, and C-stretch 568 were observed in 5 (7.9%), 7 (11.1%), and 1 (1.6%) cases among the 63 families. It means the C-stretch cannot be applied to analyze the genetic pattern in the maternal lineages. Conclusively, Amp-FLP and enelargement of Y axis of electropherogram are enough for analysis of C-stretch. Analysis of C-stretch is useful for individual identification and not in the study of maternal lineages.

Key Word : Mitochondrial DNA, D-loop, C-stretch, Polymorphism and Mutation, Maternal lineage