A Study On The Genetic Structrue Of The Northern Pinghua Han Population In Guangxi

The studies on the genetic structure of Han Chinese have been well performed. The Y chromosome and mtDNA data of all Han Chinese branches have been reported except Pinghua population, demonstrating a strong coherent genetic structure. As an old branch of Han, Pinghua people scatter in and around Guangxi Province, where Daic and Hmong-Mien take the predominance in population. The genetic structure of Pinghuas is then doubted to be exceptional. Here we studied 470 individuals (including 195 males) from Pinghua population and other surrounding ethnic groups (Zhuang, Kam, Mulam, Laka, and Mien) from five areas (Hezhou, Fuchuan, Luocheng, Jinxiu, and Wuxian) in the north of Guangxi Zhuang Autonomous Region of China. Both mtDNA and Y chromosome were typed in these samples. As a result, high frequencies of the Y chromosome haplogroup K, O~*, and O2a~*, which are the most frequent haplogroups in the southern aborigines, were found in Pinghua populations. Only Pinghua populations in Luocheng and Jinxiu maintain the Han frequent haplogroup O3a5. MtDNA lineages, B4a, B5a, M~*, F1a, M7b1, and N~* were found in Pinghua populations, exhibiting a pattern similar to the neighboring aboriginal populations, especially the Daic populations. Clustering analyses (dendrograms, principal component analyses, and networks) of Pinghua populations, the other Han branches, and other ethnic groups in East Asia indicated that Pinghua populations are much closer to the southern aborigines than to the other Han branches. Admixture analyses confirmed this result. In conclusion, we argued that Pinghua populations did not descend from Han Chinese, but from southern aborigines. The ancestral populations of Pinghua people were assimilated by Han Chinese in language, culture, and self-identification, therefore, became an exceptional branch of Han Chinese's coherent genetic structure.