Genetic origin of Kadai-speaking Gelong people on Hainan island viewed from Y chromosomes.

The government of China defined 56 official ethnicities for the ethnic groups in China for political purposes; however, there are many more than 56 ethnic groups. Therefore, similar groups must be pooled for registry, and the so-called ethnicity identification is an important official mission in China. Here, we showed how genetics can help in the ethnicity identification for the Gelong people on Hainan Island. The Gelong speak a Kadai language whose other speakers (officially of the Gelao ethnicity) are all far in the southwest of China. Being registered as a Han ethnicity, the Gelong lost all the benefits assigned to the minorities. Y-chromosome typing was performed in a sample of 78 individuals. Twenty single nucleotide polymorphisms (SNPs) and seven short tandem repeats (STRs) were typed and eight haplogroups were detected, among which haplogroup O1a* was the most dominant. Compared with the Y haplogroups of the populations in south China, the Gelong were found to be closest to the Gelao and the Hlai using principal components (PCs) analysis, dendrogram clustering and STR networks. The genetic similarity between the Gelong and the Hlai may have resulted from the gene flow during thousands of years of neighboring history on Hainan Island, whereas the similarity between the Gelong and the Gelao may have resulted from their common ancestry because there is less possibility of gene flow over such a far distance. As both linguistic and genetic evidence support the similarity between the Gelong and the Gelao, we suggest that the Gelong register as Gelao for their official ethnicity. However, this identification is invalid until it is accepted by the Gelong people themselves and the Hainan government.

Paternal genetic structure of Hainan aborigines isolated at the entrance to East Asia.

BACKGROUND: At the southern entrance to East Asia, early population migration has affected most of the Y-chromosome variations of East Asians. METHODOLOGY/PRINCIPAL FINDINGS: To assess the isolated genetic structure of Hainan Island and the original genetic structure at the southern entrance, we studied the Y chromosome diversity of 405 Hainan Island aborigines from all the six populations, who have little influence of the recent mainland population relocations and admixtures. Here we report that haplogroups O1a* and O2a* are dominant among Hainan aborigines. In addition, the frequency of the mainland dominant haplogroup O3 is quite low among these aborigines, indicating that they have lived rather isolated. Clustering analyses suggests that the Hainan aborigines have been segregated since about 20 thousand years ago, after two dominant haplogroups entered East Asia (31 to 36 thousand years ago). CONCLUSIONS/SIGNIFICANCE: Our results suggest that Hainan aborigines have been isolated at the entrance to East Asia for about 20 thousand years, whose distinctive genetic characteristics could be used as important controls in many population genetic studies.

[Detection of deletional determinants of alpha-thalassemia in Li people in Hainan province by a single tube multiplex polymerase chain reaction method].

OBJECTIVE: To develop a single tube multiplex polymerase chain reaction technique (mPCR) and use it to screen 3 deletional alpha-globin genes, namely -alpha(3.7), -alpha(4.2) (single gene deletion), and --SEA (South East Asia double gene deletion) in the Li people in Hainan province. METHODS: Based on previously developed 3 separate PCR methods used to detect the -alpha(3.7), -alpha(4.2), --SEA respectively, a single tube mPCR was investigated, optimized, and used to detect the genotypes of 40 samples from well-known alpha-thalassemia patients and 116 non-relative individuals of Li nationality in Hainan province. RESULTS: The results of the 40 samples detected by mPCR were the same as those by the 3 separate PCR Methods. Among the 116 sample, the combined incidence of -alpha(3.7) and -alpha(4.2) was found to be as high as 38.0%, and the -alpha(4.2) genotype was more frequent than the -alpha(3.7) genotype in the Li people. No --(SEA) deletion was found in the Li people. CONCLUSION: The mPCR technique shows a good sensitivity and specificity. The Hainan Li people has the highest incidence of -alpha(3.7) and -alpha(4.2) among Chinese.

[Y-chromosome-specific microsatellite variation in Li ethnic groups of Hainan Island, China].

OBJECTIVE: The study was conducted to reveal the distribution of genetic polymorphism of four Y chromosome specific short tandem repeat (Y-specific STR) loci in Li ethnic groups in Hainan Island, China. METHODS: Four tetranucleotide STR loci were simultaneously amplified with fluorescently labeled primers, and genotypes were determined with an automated DNA sequencer. RESULTS: Among 230 unrelated males, the alleles at the four Y-specific STR loci were composed of some complex repeat structure. 4,5,4,5 alleles were observed in loci DYS3891, DYS390, DYS391, DYS393 respectively. A set of human allele ladders for the typing of the four Y-specific STRs was obtained in Li ethnic population. Gene diversity index (D) and haplotype diversity data were estimated for the four Y-STRs. CONCLUSION: The preliminary study indicates a reference population for detecting male migration events and should be useful in population genetics and forensic applications.

[Polymorphism analysis for DYS19 and DYS287 of three Li populations in Haina Island, China].

The distribution of Y-chromosome specific microsatellite DYS19, in 289 males of three ethnic populations in Hainan Island was studied with the method of PCR followed by denatured polyacrylamide gel electrophoresis and silver staining. The three ethnic populations are Bendi Li, Qi Li and Ha Li. The results showed that four alleles (190bp, 194bp, 198bp, 202bp designated as alleles B, C, D and E respectively), were observed in DYS19, the frequency ranged from 0.660-0.854, and was predominant in three Li subgroups. The pairwise comparison with Fisher's Exact test reveals that there exists significant difference (P<0.01) in DYS19 phenotype distribution between Qi Li and Ha Li populations. The polymorphism of the Y-chromosome specific Alu insert sequence DYS287 was investigated also in three Li populations. The results demonstrated that with 150 bp product in all Bendi-Li, Qi-li and Ha-li, YAP element is absent. The preliminary study provides reference populations for detecting male migration events and for reconstructing paternal history.