Population genetics and forensic efficiency of 30 InDel markers in four Chinese ethnic groups residing in Sichuan

摘要

Sichuan Province is located at the transitional junction regions of the Qinghai-Tibet Plateau and the low-altitude plains. It also serves as the corridor of Sino-Tibetan-speaking population migration and expansion since neolithic expansion of Proto-Tibeto-Burman populations from Middle/Upper Yellow River during Majiayao period (3300-2000 BC). However, the population structure and the corresponding genetic diversity of forensic-related markers in this region remain unclear. Thus, we genotyped 30 insertion-deletion (InDel) markers in 444 samples from four ethnic groups (Han, Tibetan, Hui and Yi) from Sichuan Province using the Investigator'' DIPplex kit to explore the characteristics of population genetics and forensic genetic focuses. All the loci were found to be in Hardy-Weinberg Equilibrium (HWE) after applying a Bonferroni correction and no pairwise loci showed prominent linkage disequilibrium. The combined matching probability (CMP) and the combined power of discrimination (CPD) are larger than 1.8089 x 10(-11) and 0.99999999995, respectively. Principal component analysis, multi-dimensional scaling plots and Neighbour-Joining tree among 65 worldwide populations indicated that Sichuan Hui and Han are genetically dose to Hmong-Mien and Tai-Kadai-speaking populations, and Sichuan Tibetan and NI bear a strong genetic affinity with Tibeto-Burman-speaking populations. The model-based genetic structure further supports the genetic affinity between the studied populations and linguistically dose populations.