Relaciones genéticas y patrones de estructura entre mestizos y etnias mexicanas revelados por marcadores el crmosoma y

Abstract

We analyzed 6 Y-STRs, and two binary loci (M3 and YAP) in Mexican and relevant worldwide populations. The paternal ancestry in western Mestizos was estimated: European (60-64%), Amerindian (25-21%), and African (~15%). A low but significant genetic heterogeneity was established between Mexican populations; it was three times greater among tribes than Mestizos (Fst= 9.3 vs. 3.1%). Inethnicgroups,it In ethnic groups, was due to the geographically isolated groups from the Sierra Madre (Huichols and Tarahumaras), and highest Amerindian ancestry in Mestizos from Mexico City regarding Jalisco and Chihuahua states. Two different Pre-Hispanic evolutionary processes were evident. In Mesoamerica, a higher migration rate (Nm = 24.76) was estimated, promoting genetic homogeneity. Conversely, geographically isolated groups presented lower migration rate (Nm= 10.27), and stronger genetic diffe-rentiation processes (i.e. genetic drift). Among Mexican ethnic groups, Huichols and Nahuas displayed the lowest and highest admixture level, respectively. Tarahu-maras were distinctive by a high frequency of Native-American Y-chromosomes, but without Q3 (i.e. Q-P36*, M242, etc.). In Purépechas, a special admixture process involving preferential integration of non-Purépecha women in their communities could explain contrary genetic evidences (autosomal vs. Y-chromosome) of admix-ture in this group.