title: Sheep mitochondrial heteroplasmy arises from tandem motifs and unspecific PCR amplification.
abstract: The mitochondrial DNA control region (D-loop) is a widely used molecular marker in evolutionary and phylogeographic research. However, the occurrence of heteroplasmy of the D-loop region within individuals has rarely been investigated. In this study, a total of 85 Chinese sheep were used to amplify a partial D-loop region, and 15 heteroplasmic animals (17.64%) were identified. A comparative analysis of the PCR amplification and cloning of the D-loop sequences from the heteroplasmic samples revealed most of the sequencing profile from the heteroplasmic regions started at the beginning of a 75-bp random repeat motif. In addition, a total of 22 nonsyngeneic sequences with a D-loop were found in 61 of the clones obtained from the 4 random heteroplasmic and 3 homozygote animals, and their genomic locations were compared for homology. In summary, the D-Loop sequencing profiles appear to be heteroplasmic and could arise from tandem repeat motifs and unspecific replication during PCR amplification; however, they are not likely due to the presence of multiple mitochondrial genomes within an individual.
authors.affiliation: a College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivore, Chongqing Engineering Research Center for Herbivores Resource Protection and Utilization , Southwest University , Chongqing , China.
authors.forename: Guang-Xin
authors.initials: GX
authors.lastname: E
authors.affiliation: a College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivore, Chongqing Engineering Research Center for Herbivores Resource Protection and Utilization , Southwest University , Chongqing , China.
authors.forename: Yong-Ju
authors.identifier: 0000-0001-9256-8856
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: a College of Animal Science and Technology, Chongqing Key Laboratory of Forage & Herbivore, Chongqing Engineering Research Center for Herbivores Resource Protection and Utilization , Southwest University , Chongqing , China.
authors.forename: Yong-Fu
authors.initials: YF
authors.lastname: Huang
mesh_terms: D000818:Animals; D014644:Genetic Variation; D054629:Genome, Mitochondrial; D008928:Mitochondria / Q000235:genetics*; D010802:Phylogeny; D012045:Regulatory Sequences, Nucleic Acid; D012756:Sheep / Q000235:genetics*; D020080:Tandem Repeat Sequences
keywords: Chinese sheep; Heteroplasmy; mtDNA control region; tandem repeats