X-chromosomal STRs for genetic composition analysis of Guizhou Dong group and its phylogenetic relationships with other reference populations

Abstract

Background

X-chromosomes show a specific genetic mode, which makes genetic markers on the X-chromosome play crucial roles in forensic research and human evolution. Dong group, one of 55 minority groups in China, live in Guizhou, Guangxi, and Hunan provinces. Even though some genetic data of Y chromosomal short tandem repeats (STRs) and autosomal insertion/deletion polymorphism (InDels) in Dong groups have been reported, there is little research about X-STRs in the Dong group.

Aim

Purposes of this study are to investigate allelic distributions and forensic statistical parameters of 19 X-STRs in the Guizhou Dong group, and explore the genetic composition of the Guizhou Dong group and its phylogenetic relationships with other reference populations.

Subjects and methods

Five hundred and seven Dongs (272 males and 235 females) living in Guizhou province were typed using the AGCU X19 STR kit. Allelic frequencies and forensic parameters of 19 X-STRs in the Guizhou Dong group were calculated. Population genetic analyses of Guizhou Dong and another 17 reference populations were conducted using D_A genetic distances, phylogenetic tree, principal component analysis, and multidimensional scaling.

Results

A total of 230 alleles of 19 X-STRs were identified in all Dongs. The frequencies of 19 loci ranged from 0.0013 to 0.6838. The values for cumulative power of discrimination in males (PDM), cumulative power of discrimination in females (PDF), and four different kinds of mean exclusion chance (MEC_Kruger, MEC_Kishida, MEC_Desmarais, and MEC_Desmarais_du) for the 19 X-STRs in all individuals were 0.999999999999761, 0.9999999999999999999993951, 0.999999964841617, 0.999999999997261, 0.999999999997297, and 0.999999993623172, respectively. Besides, genetic polymorphisms of seven linkage clusters ranged from 0.9381 to 0.9963. In addition, these seven groups showed high polymorphism information content (PIC), PDM, PDF, MEC_Kruger, MEC_Kishida, MEC_Desmarais, and MEC_Desmarais_duo. Population genetic analyses of Guizhou Dong and another 17 reference populations showed that the Guizhou Dong group had close genetic relationships with surrounding Tai–Kadai-speaking, Hmong-Mien-speaking, and Han groups.

Conclusion

Nineteen X-STRs displayed high genetic diversities and could be employed for forensic personal identification and paternity analysis in the Guizhou Dong group. Close genetic affinities between Guizhou Dong and surrounding populations were observed based on the 19 X-STRs in 17 reference populations.

Keywords:

• Guizhou Dong
• X-STR
• genetic affinity
• population genetics
• forensic research

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by the Guizhou Scientific Support Project, Qian Science Support ([2021] General 448); Shanghai Key Lab of Forensic Medicine, Key Lab of Forensic Science, Ministry of Justice, China (Academy of Forensic Science) (Open Project KF202009); Guizhou Province Education Department, Characteristic Region Project (Qian Education KY No. [2021]065); Guizhou “Hundred” High-level Innovative Talent Project (Qian Science Platform Talents [2020]6012); Guizhou Scientific Support Project (Qian Science Support [2020]4Y057); Guizhou Science Project (Qian Science Foundation [2020]1Y353); Guizhou Scientific Support Project (Qian Science Support [2019]2825); Guizhou Scientific Cultivation Project (Qian Science Platform Talent [2018]5779-X); Guizhou Engineering Technology Research Centre Project (Qian High-Tech of Development and Reform Commission NO. [2016] 1345); Guizhou Innovation training program for college students ([2019]5200903).