The genetic composition of Argentina prior to the massive immigration era: insights from matrilineages of extant criollos in central-western Argentina

MOTTI J M B; RODENAK B; MUZZIO M; RAMALLO V; SANTOS M R; CASTRO C; ALFARO E L; DIPIERRI J E; SCHEIBLE M; SAUNIER J L; IRWIN J A; COBLE M D; BAILLIET G; BRAVI CM

Buenos Aires

Congreso; 23 rd World Congress International Society for Forensic Genetics; 2009

International Society for Forensic Genetics

Introduction and AimsMassive transatlantic immigration at the end of the 19th and in the first half of the 20th centuries,mostly from Europe and the Middle East, significantly modified the human genetic landscape ofArgentina. In an attempt to analyze the genetic composition of the country prior to this radicalchange, mtDNA control region sequences from individuals self-described as criollos from the cities of San Juan and La Rioja in central-west Argentina were obtained.Materials and MethodsBlood or saliva samples and genealogical info were obtained from voluntary participants at public hospitals in the cities of San Juan (N=112) and La Rioja (N=244). A subset of those individuals who stated no known alochtonous ancestry for their maternal line were selected as a proxy for the middle-19th century population of the area. MtDNA complete control region sequences were obtained and assigned to major continental clades in N=82 individuals from La Rioja and N=83 from San Juan.Results and DiscussionA high proportion of maternal lineages of Native American ancestry (>86 %) was found in bothpopulations, as well as similar inputs stemming from West Eurasia (LR=8,5%, SJ=9,6%), andsub-saharan Africa (LR=3,7%, SJ=3,6%). It is interesting to remark the relatively high ratio ofAfrican lineages in the alochtonous fraction. Differences were noted in the Native American share: higher frequencies of haplogroup D1 and lower frequencies for haplogroups A2, B2 and C1b were present in La Rioja while D4h3 and C4 lineages were restricted to San Juan.