Forensic characteristics and genetic affinity analyses of Xinjiang Mongolian group using a novel six fluorescent dye-labeled typing system including 41 Y-STRs and 3 Y-InDels

Abstract

Background: Y-chromosomal genetic marker haplotypes of individuals can define the paternal kinship or genealogies to which they belong and further provide clues for forensic individual identifications. Studying the genetic structure of the Mongolian group will help to bring to light the Mongolian ethnic origin, and explicate the genetic affinities among the studied and compared populations. Some forensic scientists have studied the genetic background of the Mongolian group based on different molecular genetic markers. These studies were of very great reference significance for the Mongolian group genetic research, whereas the investigation of Y-STR haplotype data in the Xinjiang Mongolian group is still insufficient.

Methods: Genetic characteristics of 182 unrelated healthy male Mongolian individuals were revealed by 41 Y-chromosomal short tandem repeat and 3 insertion/deletion molecular genetic markers. Furthermore, analyses of molecular variance programs, multi-dimensional scaling plots, and phylogenetic tree reconstructions were operated to explore the genetic relationships of the Xinjiang Mongolian group with comparative 23 populations from China and 33 populations from worldwide nations.

Results: The genetic diversity values ranged from 0.0641 (rs771783753) to 0.9502 (DYF387S1). A total of 165 distinct haplotypes were identified, of which 150 (90.91%) were unique. The discrimination capacity, match probability, and haplotype diversity of 44 loci were 0.9066, 0.0067, and 0.9988, respectively. Additionally, the Mongolian group had the most intimate relationship with Gansu Dongxiang (R_ST = 0.0165), followed by HulunBuir Mongolian (R_ST = 0.0187), Inner Mongolia Daur (R_ST = 0.0202) as well as other three minority ethnic groups from the Xinjiang region (R_ST < 0.05) in all compared Chinese populations, and clustered together with the majority of Asian populations in a worldwide scale.

Conclusions: Consequently, the 44 loci could be well applied in forensic applications of the Mongolian group. The haplotypes available in here made new contributions to the existing population genetic information and would be of great value in population studies.

Keywords: Mongolian ethnic minority; Y-chromosome STR; forensic genetics; population genetic analysis.