Genetic reconstruction and phylogenetic analysis by 193 Y-SNPs and 27 Y-STRs in a Chinese Yi ethnic group

Yi is the seventh-largest ethnic group in China and features mountainous regional characteristics. The Liangshan Yi Autonomous Prefecture is the largest Yi agglomeration with isolated geographical conditions, profoundly impeding genetic communication. Here, we investigated 427 unrelated males of Liangshan from 193 Y-chromosome single nucleotide polymorphisms (Y-SNPs) and 27 Y-chromosome short tandem repeats (Y-STRs) to reveal the genetic structure and paternal phylogeny of the group. The haplogroup diversity reached 0.9169 with 46 different subhaplogroups by 193 Y-SNPs, and the haplotype diversity reached 0.9999 by 27 Y-STR loci. Multidimensional scaling (MDS), N-J tree, and Network were constructed to decipher and visualize the genetic relations between Yi and worldwide groups. Our results revealed: (1) the Network by Y-STRs and Y-SNPs showed the haplogroup D1a1a-M15 in the Liangshan Yi population was a ramification of Tibetan groups' expansion from west to east on the plateau; (2) the haplogroup distribution and the mismatch mutation analysis indicated the haplogroup O2a2b1a1a1a4a2-Z25929 of Liangshan Yi derived from manifold Southeast Asian immigrants; (3) a high-resolution Y-SNPs panel is vital to depict accurate paternal derivations and build an integrated and refining genetic structure of ethnic groups.

Automated summary

The genetic structure and paternal lineage of the Yi ethnic group in Liangshan were investigated using Y-chromosome SNPs and STRs, revealing connections to Tibetan groups' expansion and Southeast Asian immigrants. High-resolution Y-SNPs panels are crucial for accurately depicting paternal derivations and refining the genetic structure of ethnic groups.