Inferring the genetic structure of Northwestern Argentina by uniparental SNP typing

Abstract

The genetic background of South American populations is the result of four major genetic admixture events. To investigate the maternal and paternal lineages, we analyzed mitochondrial DNA (mt-DNA): A2, B2, C, D1; and Y-chromosome (Y-DNA) haplogroups (hg): R1b1b2, Q1a3a, G2a, I, J2, E1b1b, based on SNP typing by real time PCR and high-resolution melting analysis. Individuals from Northwestern Argentina (NWA) (n = 187) were studied and compared with Buenos Aires Metropolitan Area´s inhabitants (BUE) (n = 107) and recently arrived immigrants from Bolivia (BOL) (n = 100), Paraguay (PAR) (n = 54) and Peru (PER) (n = 52). Native American (NA) mt-DNA hgs were the most frequent in all regions (89,8%?98,1%), except for BUE (43%), being B2 the most prevalent (42,6%?58% versus 8,4% in BUE). Regarding Y-DNA hg, a greater contribution of the non-Native American (non-NA) lineage was found in all populations (61,5%?99%), except for BOL (32,7%). Moreover, the most frequent hg observed were R1b1b2 (50% PAR, 46,6% BUE, 30,2% NWA) and Q1a3a (67,3% BOL, 38,5% PER). A high percentage of NA mt-DNA/non-NA Y-DNA was represented (53,8%?63,5%), excepting BUE (41,7%) and BOL (26,9%). Data obtained is consistent with historical information underscoring the complex genetic ancestry of melting pot countries. The results offer additional tools for forensic investigation; molecular epidemiological and anthropological studies.