The Ong Be language-speaking population in Hainan Island: genetic diversity, phylogenetic characteristics and reflections on ethnicity.

The Ong Be language-speaking population (Lingao population) settled in the north-central coast of Hainan Island and has attracted little attention because of its small population size (about five hundred thousand) as well as its relative geographical isolation in linguistics, anthropology, and forensic genetics. The Lingao population selected "Han Chinese" as its ethnic component around the founding period of the PRC. Hence, we used the Goldeneye™ DNA ID System 20A (including 13 CODIS core loci and 6 expanded CODIS loci) to obtain Lingao population genotypes and to enable the publishing of relative forensic parameters; further, this data will allow the evaluation of the Lingao ethnic component from different perspectives. Genetic differences between the Lingao population and Han Chinese populations from north and south administrative divisions of China as well as genetic distinctions among official ethnic groups were also investigated by the principal component analysis (PCA). The phylogenic tree was investigated by the unweighted pair-group method with arithmetic averages (UPGMA). We analysed the genetic polymorphisms of 19 autosomal STR loci in 821 individuals from the Lingao population and observed a total of 269 alleles at 19 autosomal STR loci, with the corresponding allelic frequencies ranging from 0.0006 to 0.5780. The combined power of discrimination (CPD) and combined power of exclusion (CPE) for the 19 autosomal STR loci were 0.99999999999999999999998569 and 0.999999989, respectively. No evidence of deviation from the Hardy-Weinberg equilibrium (HWE) was identified and no linkage disequilibrium (LD) was observed. The results demonstrated that the Goldeneye™ DNA ID System 20A had highly genetic diversities in the 19 STR loci in the Lingao population for forensic applications. In addition, the Lingao population had relatively close genetic relationships with Guangxi Han and Hainan Li populations compared to other populations. However, from a historical and linguistic perspective, "Han Chinese" is probably not an accurate description of the Lingao population. In conclusion, it is neither accurate or appropriate to classify the Ong Be language-speaking population as "Han Chinese" for multiple reasons. The present study can increase our understanding of the genetic relationships between the Lingao population and other Chinese groups. Nonetheless, further genetic studies are still needed to explore the mysteries of the Ong Be language-speaking population.