Department of Molecular Biology and Genetics, School of Biomedicine, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia.
Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, Republic of Korea.
Biomed Res Int. 2020 Aug 11;2020:2585324. doi: 10.1155/2020/2585324. eCollection 2020.
This study reports the use of real-time PCR to identify the SNP rs1545397 in the intron region on the OCA2 gene from ancient and degraded DNA isolated from ancient human bones from Mongolia, Korea, and Uzbekistan. This SNP is a marker for skin pigmentation. LightCycler-based probes (HybProbes) were designed. A LightCycler (version 2.0) system was used for the real-time PCR.
The results of the real-time PCRs of three different genotypes of SNP rs1545397 were compared with those of the direct sequencing. Melting curve analysis was used for genotype determination. Three genotypes were distinguished: the homozygous T (T/T) SNP type formed a distinct melting peak at 53.3 ± 0.14°C, the homozygous A (A/A) SNP type formed a distinct melting peak at 57.8 ± 0.12°C, and the heterozygous A/T SNP type formed two distinct melting peaks at 53.3 ± 0.17°C and 57.8 ± 0.15°C. Mongolian aDNA samples tested in this study carried all three types of the SNP (A/T, A/A, and T/T) with no distinctly predominant type observed. In contrast, Korean aDNA samples carried the Asian genotype (T/T), while the Uzbekistan aDNA samples carried the European genotype (A/A) more often than the Asian genotype (T/T).
Human Mongolian aDNA samples had A/T, A/A, and T/T SNP rs1545397 with no distinct predominant genotype. When combined with the archeological and aDNA studies of other coupling morphologies with aDNA, our results infer that Mongolia's prehistoric population had considerable heterogeneity of skin color and morphological traits and that in the Neolithic period, a Eurasian or mixed population inhabited the western part of Mongolia.
本研究报告了使用实时 PCR 从蒙古、韩国和乌兹别克斯坦的古代人类骨骼中分离出的降解 DNA 中鉴定 OCA2 基因内含子区域 SNP rs1545397 的方法。该 SNP 是皮肤色素沉着的标志物。设计了基于 LightCycler 的探针（HybProbes）。使用 LightCycler（版本 2.0）系统进行实时 PCR。
三种不同基因型 SNP rs1545397 的实时 PCR 结果与直接测序的结果进行了比较。使用熔解曲线分析进行基因型确定。区分了三种基因型：纯合 T（T/T）SNP 类型在 53.3 ± 0.14°C 形成明显的熔解峰，纯合 A（A/A）SNP 类型在 57.8 ± 0.12°C 形成明显的熔解峰，杂合 A/T SNP 类型在 53.3 ± 0.17°C 和 57.8 ± 0.15°C 形成两个明显的熔解峰。本研究中测试的蒙古古代 DNA 样本携带 SNP 的所有三种类型（A/T、A/A 和 T/T），没有观察到明显占主导地位的类型。相比之下，韩国古代 DNA 样本携带亚洲基因型（T/T），而乌兹别克斯坦古代 DNA 样本携带欧洲基因型（A/A）的频率高于亚洲基因型（T/T）。
人类蒙古古代 DNA 样本具有 SNP rs1545397 的 A/T、A/A 和 T/T，没有明显占主导地位的基因型。当与其他与古代 DNA 结合的耦合形态的考古学和古代 DNA 研究相结合时，我们的结果推断蒙古史前人口的皮肤颜色和形态特征具有相当大的异质性，并且在新石器时代，欧亚或混合人口居住在蒙古西部。
