Ancestral proportions based on 22 autosomal STRs of an admixed population (Mestizos) from the Península of Yucatán, México

Abstract

Latin American populations trace their ancestry mainly to Post Columbian admixture among Native Americans (NA), Europeans, and Africans during nearly 500 years. Although historic and anthropological records suggest that the Peninsula of Yucatan (Southeast, Mexico) has as a large NA origin principally of Mayan ethnicity, they have been poorly studied with autosomal STRs. Thus, the ancestral proportion of Mestizos (admixed) from the Peninsula of Yucatan, was assessed by genotyping 687 subjects for 22 autosomal STRs (Powerplex Fusion system). STR databases from other Mexican Mestizos were included for the admixture analysis (North, West, and Center regions), Hispanic Americans, in addition to European, NA, and African genetic pools as ancestral references. The best fit of population clusters obtained with Structure (K = 5), suggests that Mestizos from the Southeast are principally composed by NA (64.9%), followed by European (33.7%) and African (1.3%) ancestries. This was the highest among the compared Mexican Mestizo populations (range: 51.5–64.3%) and Hispanics (32.9%). Conversely, the European ancestry in the southeast is the lowest among Mexican-Mestizos (range: 33.7–48.5%) and Hispanics (60.2%). Differences with previous reports based on lesser number of STRs could be explained by intrapopulation structure due to socioeconomic and educational factors, as has been previously described in Mexican-Mestizos. This particular ancestral landscape justifies the creation of local STR databases for human identification purposes in Mexico.