Genetic Characterization of Indigenous Peoples from Oaxaca, Mexico, and Its Relation to Linguistic and Geographic Isolation

Abstract

We used 15 short tandem repeat (STR) loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, and FGA) to genetically characterize 361 individuals from 11 indigenous populations (Amuzgo, Chinanteco, Chontal, Huave, Mazateco, Mixe, Mixteco, Triqui, Zapoteco del Istmo, Zapoteco del Valle, and Zoque) from Oaxaca, Mexico. We also used previously published data from other Mexican peoples (Maya, Chol, Tepehua, Otomí, and Mestizos from northern and central Mexico) to delineate genetic relations, for a total of 541 individuals. Average heterozygosity (H) was lower in most populations from Oaxaca (range 0.687 in Zoque to 0.756 in Chontal) than values observed in Mestizo populations from Mexico (0.758 and 0.793 in central and northern Mestizo, respectively) but higher than values observed in other Amerindian populations from South America; the same relation was true for the number of alleles (n(a) ). We tested (using the software Structure) whether major geographic or linguistic barriers to gene flow existed among the populations of Oaxaca and found that the populations appeared to constitute one or two genetic groups, suggesting that neither geographic location nor linguistics had an effect on the genetic structure of these culturally and linguistically highly diverse indigenous peoples. Moreover, we found a low but statistically significant between-population differentiation. In addition, the genetic structure of Oaxacan populations did not fit an isolation-by-distance model. Finally, using AMOVA and a Bayesian clustering approach, we did not detect significant geographic or linguistic barriers to gene flow within Oaxaca. These results suggest that the indigenous communities of Oaxaca, although culturally isolated, can be genetically defined as a large, nearly panmictic population in which migration could be a more important population mechanism than genetic drift. Finally, compared with outgroups in Mexico (both indigenous peoples and Mestizos), three groups were apparent. Among them, only the Otomí population from Hidalgo has a different culture and language.

Importance of the geographic barriers to promote gene drift and avoid pre‐ and post‐Columbian gene flow in Mexican native groups: Evidence from forensic STR Loci

“…In general, this panorama is in agreement with the lack of differentiation described for Mesoamerica respect to Native American groups throughout the continent (Wang et al, ), and the high population density concomitant to the agricultural development (Fiedel, ; Cavalli‐Sforza et al, ). Similarly, this finding partially harmonizes with the elevated human mobility described between groups from Oaxaca (Quinto‐Cortés et al, ). Although our conclusions could be biased by the relatively high admixture level detected in Native groups from the Central region and Yucatan Peninsula (Fig.…”

“…Nevertheless, in Mexican Native groups the progress has been slower and only in recent years the number of studied populations has increased importantly. For instance, the 15 STRs highly used for human identification purposes have been characterized in Choles (Sánchez et al, ), Otomies and Huastecos (Barrot et al, ), Tepehuas (González‐Martín et al, ), Mayas, Purépechas and Triquis (Ibarra‐Rivera et al, ; Martínez‐Cortés et al, ), and 10 indigenous groups from Oaxaca (Quinto‐Cortés et al, ). More recently 9 and 10 Native American groups from the North and Northwest, as well as from the West, Center, and Southeast of Mexico were reported, respectively (Rangel‐Villalobos et al, ).…”

Weight status of indigenous youth in Oaxaca, southern Mexico: concordance of IOTF and WHO criteria

“…Although indigenous groups in Oaxaca are linguistically distinct and to some extent culturally isolated, data for 15 short tandem repeat loci among 11 of the indigenous groups indicated they were quite similar genetically (Quinto-Cortés et al, 2010). Studies of variation in mitochondrial DNA and autosomal satellite markers indicated Zapotec, Mixtec and Mixe as more closely related (as a cluster) compared to other populations in Mexico and Central America (Hunley & Healy, 2011;Torroni et al, 1994;Wang et al, 2007).…”

Thinness, overweight and obesity in indigenous youth in Oaxaca, 1970 and 2007

“…Although indigenous groups of Oaxaca are linguistically and to some extent culturally isolated, they are rather homogeneous genetically. 32 The Zapotec, Mixtec and Mixe also form a closely related genetic cluster distinguished from other populations in Mexico and Central America. [33][34][35] Other indigenous groups from Oaxaca were not represented in the latter analyses.…”