Decoding Maternal Genetic Background of Chinese Tujia Minority Ethnic Group through Extensive Mitochondrial Genome Analyses

Chong Chen¹Man Chen²Lintao Luo¹Ying Zhu¹Hongbing Chen¹Minzhu Zhao¹Yuhang Cao¹Yongguo Li¹Li Lan¹Chunmei Shen^3*Jianbo Li^1*

• ¹Chongqing Medical University, Chongqing, China
• ²Academy of Forensic Science Shanghai Key Laboratory of Forensic Medicine, Shanghai, China
• ³Southern Medical University Nanfang Hospital, Guangzhou, China

The Tujia ethnic group, belonging to the Tibeto-Burman linguistic family, primarily resides in the mountainous regions of central and southern China. Despite their substantial population size and rich historical background, the maternal genetic characteristics of the Tujia have been insufficiently studied, especially regarding the complete mitochondrial genome. In this study, we obtained 131 complete mitochondrial sequences from healthy, unrelated Tujia individuals in Chongqing utilizing MPS technology. To facilitate population genetic analyses, we selected 8,861 global modern individuals and 1,635 ancient individuals as references. Our findings revealed that the Chongqing Tujia exhibited significant representations of maternal haplotypes prevalent in East Asia, especially in southern East Asia. Bayesian and phylogenetic tree analyses indicated that the Tujia likely experienced several distinct population expansions during their formation. Additionally, for modern populations, the intimate matrilineal relationships between the Tujia and neighboring populations suggest that recent population admixture might be pivotal in shaping the genetic diversity observed in modern Tujia, such as that of the Han populations. Notably, the Tujia also evidently demonstrated genetic links to geographically distant populations, such as Austronesian populations. For ancient populations, the Tujia demonstrated notably close maternal genetic affinities with ancient populations from the Yellow River Basin, particularly during the Late Neolithic to Early Bronze Age. Finally, based on both modern and ancient population analyses, our findings suggested that the maternal genetic structure of the Chongqing Tujia might still carry imprints from Tibetan progenitors. This study provided a comprehensive understanding of the maternal lineage and genetic diversity of Chongqing Tujia, offering valuable data for research on the genetic diversity and evolutionary history of Chinese ethnic minorities.