LAUSR

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% to 98,1%), except for BUE (43%), being B2 the most prevalent (42,6% to 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% to 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% to 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.