Genetic structure and admixture in urban populations of the Argentine North-West.
BACKGROUND
From the ethnic point of view, the Argentine North-West (ANW) constitutes one of the most noticeable areas in the country due to the cultural peculiarities that integrate it to the Andean world and the ethno-historical and demographic characteristics of how it became populated.


OBJECTIVE
The study analysed the genetic structure and diversity of the ANW urban populations, and the contribution of parental populations to its genetic pool.


METHODS
Previously reported data on allele frequencies of HLA-A and HLA-B loci of 1293 individuals from Jujuy, Salta, Tucumán, Santiago del Estero, Catamarca and La Rioja were used. Our estimates include: (a) genetic intra-population diversity; (b) genetic distances between populations; (c) linkage disequilibrium (LD); (d) admixture rates and genetic distances with respect to three parental populations (European, American Indian and African).


RESULTS
Low intra-population genetic differentiation and low genetic distances between populations were found. Differential LD distribution varied according to province, with 60% variance due to intra-population differences. The Spanish contribution (50%) predominated in ANW, followed by the American Indian (40%) and African (10%) contributions, and a marked inter-population heterogeneity of genetic admixture rates was observed. The shortest genetic distance was found in the American Indian parental population, and the longest in the African parental population.


CONCLUSIONS
Five hundred years after the Spanish conquest, urban populations at ANW that have probably been subject to the same evolutionary forces present low genetic diversity and a similar genetic structure. Genetic distances and admixture percentages observed agree with census and ethno-historical data on settlement in the region.
Alfaro
E L
EL
Instituto de Biología de la Altura, Universidad Nacional de Jujuy, Jujuy, Argentina. ealfaro@inbial.unju.edu.ar
Dipierri
J E
JE
Gutiérrez
N I
NI
Vullo
C M
CM
D001118:Argentina; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D006801:Humans; D007199:Indians, South American / Q000235:genetics*; D015810:Linkage Disequilibrium / Q000235:genetics; D008297:Male; D014505:Urban Population