The optimization of aDNA extraction protocol and sex determination of Bronze Age individuals from Oylum Hoyuk (Kilis, Turkey)

Abstract

Oylum Hoyuk falls within the borders of the province of Kills, located in the southern part of Turkey. It is an important Bronze Age settlement dating back to 5500 BC. In this study, the sex of 36 individuals found in Oylum Hoyuk was examined using morphological and genetic methods. In the morphological method, sex was identified in 14 female and 13 male individuals. The remaining 8 individuals could not be identified due to the poor preservation of their skeletal remains. Genetic sex was determined with the amplification of sex-specific X, Y centromeric alphoid repeats and ZFX-ZYF gene regions of DNA, mostly extracted from teeth. Based on ZFX-ZYF gene regions, sex was successfully determined using the PCR-RFLP method. The amplification results of ZFX-ZYF gene regions were also tested by applying the PCR-RFLP method. The amplification of X, Y centromeric alphoid repeats was successful in 29 individuals, while sex determination based on ZFX-ZFY fragments was carried out in 22 individuals. The vast majority of the results determined by analysis of ancient DNA were consistent with the morphological method. However, these 2 methods produced slightly different results for 5 individuals. Finally, the results indicated that ancient DNA analysis is a reliable method for sex determination, especially in poorly preserved and fragmented skeletal remains.