Evaluation of forensic and anthropological potential of D9S1120 in mestizos and Amerindian populations from Mexico

Abstract

Aim: To carry out a deeper forensic and anthropological evaluation of the short tandem repeat (STR) D9S1120 in five Mestizo populations and eight Amerindian groups from Mexico. Methods: We amplified the STR D9S1120 based on primers and conditions described by Phillips et al, followed by capillary electrophoresis in the genetic analyzer ABI Prism 310. Genotypes were analyzed with the GeneMapper ID software. In each population we estimated statistical parameters of forensic importance and Hardy-Weinberg equilibrium. Heterozygosity and FST-values were compared with those previously obtained with nine STRs of the Combined DNA Index System (CODIS-STRs). Results: Amerindian and Mestizo populations showed high frequencies of the allele 9 and 16, respectively. Population structure analysis (AMOVA) showed a significant differentiation between Amerindian groups (FST = 2.81%; P < 0.0001), larger than between Mestizos (FST = 0.44%; P = 0.187). D9S1120 showed less genetic diversity but better population differentiation estimates than CODIS-STRs between Amerindian groups and between Amerindians and Mestizos, but not between Mestizo groups. Conclusion: This study evaluated the ability of D9S1120 to be used for human identification purposes and demonstrated its anthropological potential to differentiate Mestizos and Amerindian populations.