Department of Military Medical Geography, Army Health Service Training Base, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
Health Department of the 957th Hospital of PLA, Ali, 859000, Tibet, China.
Sci Rep. 2020 Jun 29;10(1):10592. doi: 10.1038/s41598-020-67519-z.
High-altitude Tajiks (HA-Tajiks), Tibetans and Sherpas are three groups of high-altitude native people in China. The differences in the mtDNA genome between the three populations and the role of the mtDNA genome in the high-altitude adaptation of HA-Tajiks were seldom investigated. In this study, 80 HA-Tajiks were enrolled, and their whole mtDNA genomes were sequenced. The haplogroup of each subject was determined by comparison to the revised Cambridge Reference Sequence (rCRS). Ten additional populations from East Asia and Central Asia, including Tibetans and Sherpas, were selected as references. The top haplogroup was U, followed by H, T and J. Principle component analysis and genetic distance analysis indicated that HA-Tajiks showed a close relationship with Wakhi Tajiks, Pamiri Tajiks and Sarikoli Tajiks, indicating that they should be considered one nation scattered around the Pamirs. The difference in the mtDNA genome between HA-Tajiks and Sherpas was significantly greater than that between HA-Tajiks and Tibetans. Among the 13 genes related to the OXPHOS pathway encoded by the mtDNA genome, HA-Tajiks showed more significant differences in ND3 and CYTB compared to Tibetans. Compared to Sherpas, HA-Tajiks showed more significant differences in ND1, ND2, COX1, ATP8, ATP6, ND3, ND4L, ND4, ND5 and CYTB. The associated functional changes and underlying molecular mechanisms should be explored by molecular and biochemical investigations in further studies.
高海拔塔吉克人（HA-Tajiks）、藏族人和夏尔巴人是中国的三个高海拔原住民群体。这三个群体之间的 mtDNA 基因组差异以及 mtDNA 基因组在 HA-Tajiks 高原适应中的作用很少被研究。在这项研究中，我们招募了 80 名 HA-Tajiks，并对他们的全 mtDNA 基因组进行了测序。通过与修订后的剑桥参考序列（rCRS）进行比较，确定了每个受试者的单倍群。选择了东亚和中亚的另外 10 个群体作为参考，包括藏族人和夏尔巴人。最主要的单倍群是 U，其次是 H、T 和 J。主成分分析和遗传距离分析表明，HA-Tajiks 与瓦赫提吉克人、帕米尔吉克人和萨里科利吉克人关系密切，表明他们应该被视为散布在帕米尔高原的一个民族。HA-Tajiks 与夏尔巴人之间的 mtDNA 基因组差异明显大于 HA-Tajiks 与藏族人之间的差异。在 mtDNA 基因组编码的与 OXPHOS 途径相关的 13 个基因中，HA-Tajiks 在 ND3 和 CYTB 上与藏族人相比表现出更大的差异。与夏尔巴人相比，HA-Tajiks 在 ND1、ND2、COX1、ATP8、ATP6、ND3、ND4L、ND4、ND5 和 CYTB 上表现出更大的差异。在进一步的研究中，应该通过分子和生化研究来探索相关的功能变化和潜在的分子机制。
