The genetic landscape of South African males: A Y-STR perspective

Abstract

The profiles of 2188 SA males obtained with 10 Y-STR highly informative markers were analyzed for their information content for forensic and population studies. The samples comprised a total of 16 populations, represented by Bantu-speaking groups, KhoeSan descendants, out-of-Africa descendants and admixed groups. The country hosts approximately 58 million inhabitants, 80% native and the remaining with ancestry external to Africa and admixed. The forensic parameters indicated high levels of diversity in all populations and lower in the Nguni, who showed elevated number of repeated haplotypes, thus displaying the lowest DC values. Population comparative analysis with MDS showed concordant results with the historical record. Non-hierarchical and hierarchical AMOVA over ethnolinguistic groups and administrative divisions showed significant variation in all cases, with higher differences due to ethnicity than to geopolitical subdivision. The haplotypes were further analyzed by hierarchical kmeans clustering. The identified clusters differed in their relative contribution to the gene pool of the 16 analyzed populations. Geostatistical analysis of the clusters evidenced areas of higher density for some clusters in correspondence with language, while other clusters were more homogeneously distributed. In addition, a few rare microvariants were identified with very restricted geographic occurrence. The results emphasize the forensic value of a highly informative set of markers in a country with high genetic diversity and complex population history.