Wang Hongdan, Chen Man, Chen Chong, Fang Yating, Cui Wei, Lei Fanzhang, Zhu Bofeng
Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, China.
Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China.
Front Genet. 2022 Feb 23;13:729514. doi: 10.3389/fgene.2022.729514. eCollection 2022.
The mitochondrial DNA (mtDNA) has been used to trace population evolution and apply to forensic identification due to the characteristics including lack of recombination, higher copy number and matrilineal inheritance comparing with nuclear genome DNA. In this study, mtDNA control region sequences of 91 Kirgiz individuals from the Northwest region of China were sequenced to identify genetic polymorphisms and gain insight into the genetic background of the Kirgiz ethnic group. MtDNA control region sequences of Kirgiz individuals presented relatively high genetic polymorphisms. The 1,122 bp sequences of mtDNA control region could differ among unrelated Kirgiz individuals, which suggested the mtDNA control region sequences have a good maternal pedigree tracing capability among different Kirgiz individuals. The neutrality test, mismatch distribution, Bayesian phylogenetic inference, Bayesian skyline analysis, and the median network analyses showed that the Kirgiz group might occurred population expansion, and the expansion could be observed at about ∼53.41 kilo years ago (kya) when ancestries of modern humans began to thrive in Eurasia. The pairwise population comparisons, principal component analyses, and median network analyses were performed based on haplogroup frequencies or mtDNA control region sequences of 5,886 individuals from the Kirgiz group and the 48 reference populations all over the world. And the most homologous haplotypes were found between Kirgiz individuals and the East Asian individuals, which indicated that the Kirgiz group might have gene exchanges with the East Asian populations.
线粒体DNA（mtDNA）因其具有缺乏重组、拷贝数较高以及母系遗传等与核基因组DNA相比的特点，已被用于追踪种群进化并应用于法医学鉴定。在本研究中，对来自中国西北地区的91名柯尔克孜族个体的mtDNA控制区序列进行了测序，以鉴定遗传多态性并深入了解柯尔克孜族的遗传背景。柯尔克孜族个体的mtDNA控制区序列呈现出相对较高的遗传多态性。mtDNA控制区的1122bp序列在无关的柯尔克孜族个体之间可能存在差异，这表明mtDNA控制区序列在不同柯尔克孜族个体中具有良好的母系谱系追踪能力。中性检验、错配分布、贝叶斯系统发育推断、贝叶斯天际线分析和中位数网络分析表明，柯尔克孜族群体可能经历了种群扩张，这种扩张大约发生在距今约53.41千年前（kya），当时现代人类的祖先开始在欧亚大陆繁荣发展。基于柯尔克孜族群体的5886名个体以及来自世界各地的48个参考群体的单倍群频率或mtDNA控制区序列进行了成对种群比较、主成分分析和中位数网络分析。并且在柯尔克孜族个体和东亚个体之间发现了最同源的单倍型，这表明柯尔克孜族群体可能与东亚人群发生了基因交流。
