title: Investigation into length heteroplasmy in the mitochondrial DNA control region after treatment with bisulfite.
abstract: We report on a method to analyze length heteroplasmy within the human mitochondrial genome in which there are polycytosine [poly(C)] stretches. These poly(C) tracts induce heteroplasmy with the resultant inherent problems of accurate sequence designations. In this study, 20 samples that exhibited length heteroplasmy due to variation in the C-tracts within hypervariable region I (HVI) were treated with bisulfite, and one or more cytosine bases in these C-tracts were converted randomly to uracil. This resulted in an accurate sequence designation for nearly all samples. The only exceptions in which the DNA sequence could still not be determined occurred when there was total conversion, or a lack of conversion, of the cytosine bases. Replicate tests on the same samples showed that individual cytosine bases were randomly converted to uracil. This simple method was useful for investigating length heteroplasmy due to 16189C and 310C transitions in the mitochondrial-DNA control region. It is valuable for medical and forensic investigations.
authors.affiliation: Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
authors.forename: James Chun-I
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Forensic Science, Central Police University, Taoyuan 33304, Taiwan, ROC.
authors.forename: Li-Chin
authors.initials: LC
authors.lastname: Tsai
authors.affiliation: Department of Forensic Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC.
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Yu
authors.affiliation: Institute of Forensic Medicine, Ministry of Justice, New Taipei City, Taiwan, ROC.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Lin
authors.affiliation: School of Biological Sciences, Flinders University, Adelaide, Australia.
authors.forename: Adrian
authors.initials: A
authors.lastname: Linacre
authors.affiliation: Department of Forensic Science, Central Police University, Taoyuan 33304, Taiwan, ROC. Electronic address: mei@mail.cpu.edu.tw.
authors.forename: Hsing-Mei
authors.initials: HM
authors.lastname: Hsieh
mesh_terms: D004272:DNA, Mitochondrial / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA / Q000379:methods*; D013447:Sulfites / Q000737:chemistry*
chemical_list: D004272:DNA, Mitochondrial; D013447:Sulfites; C042345:hydrogen sulfite
keywords: C-tract; bisulfite treatment; control region; length heteroplasmy; mitochondrial DNA