Composição genética de populações do Sudeste Asiático: análise dos principais haplogrupos da região e contribuição para o entendimento das teorias das rotas de migração

Abstract

The genetic characterization of a population is extremely important, as it allows to know the history/evolution of a given country/continent, as well as the demographics of different ethnic subgroups present in certain regions. Population Genetics research has focused mainly on European regions, with Asia being underrepresented, despite being the largest and most populous continent. The present work aimed to deepen the knowledge of the genetic composition of two Southeast Asian countries, Vietnam and the Philippines, contributing to the phylogenetic study of the region and, consequently, to the understanding of the migration route theories in Southeast Asia. To this end, a first analysis of the genetic structure of both populations was performed regarding their paternal lineages. Therefore, 318 Vietnamese and 120 Filipino samples were randomly selected from male subjects. For these samples, DNA extraction and genotyping with specific Y chromosome markers (Y-SNP and Y-STR, which differ in mutation rate) were performed. Thus, it was possible to evaluate population differentiation at different time scales. Concerning Vietnamese populations, larger differences were observed between populations of the same region than between populations from different regions, indicating a weak correlation between Geography and Genetics. However, when ethnicity criteria were used, there was a genetic differentiation of the ethnic groups, which proved to be the best criterion for grouping subpopulations of Vietnam. Of the nine ethnic groups in Vietnam included in this study, Mong proved to be the most differentiated, presenting significant genetic differences with the remaining ethnic groups. In the Philippines, a small genetic distance was observed between the three main island groups (Luzon, Mindanao and Visayas), which was not significant. The results obtained in this study demonstrated that there is a great genetic diversity among individuals from the same region and a small differentiation between populations from different geographic regions. The data obtained for the Vietnamese and Philippine populations were further compared with those of other Southeast Asian populations, for which data from the same genetic markers were available. The results obtained are consistent with the existence of two migration routes on the continent of Southeast Asia, which branched close to Paskistan and followed one to the north and one to the south. On the islands of Southeast Asia, the results also suggest the existence of two routes: one going from Taiwan to Indonesia and another going in the opposite direction.