Abstract
Sabah and Sarawak form East Malaysia on the island of Borneo. They are separated from West Malaysia (i.e., Peninsular Malaysia) by the South China Sea and home to diverse indigenous Austronesian speaking populations. In this study, we analysed 257 male blood samples belonging to Austronesian speaking Murut, Bajau, Kadazan-Dusun and Melanau population groups for 27 Y-chromosome short tandem repeat (Y-STR) loci using the Yfiler™ Plus Polymerase Chain Reaction (PCR) Amplification kit. Forensic parameters such as discrimination capacity and random match probability calculated based on the newly generated population datasets from four Borneo population groups show the reliability of the tested Y-STR loci for use in forensic casework analyses. Analysis of molecular variance (AMOVA) demonstrated that 89% of the genetic variation was found within populations and 11% between populations. All four Borneo population groups clustered together with other Austronesian speaking populations from Southeast Asia (e.g., Malays, Kedayan and Iban) in the middle of the principal coordinate analysis (PCoA) plot and were slightly separated from other indigenous Austronesian speaking populations (e.g., Paiwan and Puyuma) in Taiwan. We suggest that the observed clustering patterns may stem from the limited resolution of the Y-STR marker set, rather than reflecting long-term demographic processes or Austronesian expansion model inferred from linguistic and archaeological evidence. Future research requires larger sample size and data from other genetically uncharacterized indigenous populations in Sabah and Sarawak to achieve accurate ancestry and forensic parameter estimations.