Maternal admixture and population structure in Mexican–Mestizos based on mtDNA haplogroups

Abstract

The maternal ancestry (mtDNA) has important applications in different research fields, such as evolution, epidemiology, identification, and human population history. This is particularly interesting in Mestizos, which constitute the main population in Mexico (∼93%) resulting from post-Columbian admixture between Spaniards, Amerindians, and African slaves, principally. Consequently, we conducted minisequencing analysis (SNaPshot) of 11 mitochondrial single-nucleotide polymorphisms in 742 Mestizos of 10 populations from different regions in Mexico. The predominant maternal ancestry was Native American (92.9%), including Haplogroups A, B, C, and D (47, 23.7, 15.9, and 6.2%, respectively). Conversely, European and African ancestries were less frequent (5.3 and 1.9%, respectively). The main characteristics of the maternal lineages observed in Mexican-Mestizos comprised the following: 1) contrasting geographic gradient of Haplogroups A and C; 2) increase of European lineages toward the Northwest; 3) low or absent, but homogeneous, African ancestry throughout the Mexican territory; 4) maternal lineages in Mestizos roughly represent the genetic makeup of the surrounding Amerindian groups, particularly toward the Southeast, but not in the North and West; 5) continuity over time of the geographic distribution of Amerindian lineages in Mayas; and 6) low but significant maternal population structure (FST = 2.8%; P = 0.0000). The average ancestry obtained from uniparental systems (mtDNA and Y-chromosome) in Mexican-Mestizos was correlated with previous ancestry estimates based on autosomal systems (genome-wide single-nucleotide polymorphisms and short tandem repeats). Finally, the comparison of paternal and maternal lineages provided additional information concerning the gender bias admixture, mating patterns, and population structure in Mestizos throughout the Mexican territory.

Genetic structure and forensic parameters of 38 Indels for human identification purposes in eight Mexican populations

“…The results described above, showing that Mexico is genetically sub-structured in three main geographic regions, will allow to forensic geneticists selecting the correct database to interpret DNA profiles based on these 38 Indels in the remaining 24 Mexican-Mestizo populations not previously studied for this HID system. The population structure of Mexican-Mestizos is in agreement with previous reports that describe a contrasting ancestry gradient of two major origins [6,8,9,17,18]: the European that increases toward the Northwest and, conversely, the Amerindian that intensifies toward the Center and Southeast regions of the Mexican territory. This pattern was previously related to the Pre-Hispanic demography of Mesoamerica [6,7].…”

“…This pattern was previously related to the Pre-Hispanic demography of Mesoamerica [6,7]. Moreover, the lower genetic diversity and higher differentiation of the Mestizos from Chiapas can be probably explained by an increased Amerindian ancestry, received from the large number of surrounding Native American groups inhabiting the territory, which was described in a report based on mtDNA haplogroups [9], and in a recent genome wide SNP study [7].…”

“…The uneven admixture process throughout the country has generated a complex population structure in Mestizos, which has been related to the Pre-Hispanic Mesoamerican demography [6,7]. An asymmetric admixture was also described in Mexican-Mestizos due to a predominant paternal European (Y-chromosome) and maternal Amerindian (mtDNA) contributions, which also depicts differences all through the Mexican territory [8,9]. Therefore, the setup of population databases is a complex task to get reliable estimations of DNA profile frequencies in this country.…”

Evidence for Central Asian Origin of the p.Val27Ile Variant in the GJB2 Gene

“…Censo de Población y Vivienda 2010, http://cuentame.inegi.org.mx), of them, 93% were mestizos, (resulting from post-Columbian admixture between Amerindians, Spaniards, and Africans, principally) [33]. The origin of the nuclear DNA from current Mexican mestizo population has been estimated to be 55.3% Amerindian (Native American), 42.2% European, 3.3% African, and 1.2% East Asian (Philippines).…”

A Mitochondrial Haplogroup Is Associated with Decreased Longevity in a Historic New World Population

“…Unfortunately, haplogroup and longevity studies have been limited to a small number of populations, predominantly Chinese (Cai et al, 2009;Feng et al, 2011;Lv et al, 2010;Yang et al, 2012), Japanese (Nishigaki et al, 2010), and European (Courtenay et al, 2012;Dominguez-Garrido et al, 2009;Guney et al, 2014;Pinos et al, 2012) [see (Castri et al, 2009) for older citations] and have only worked with living subjects. It is striking that even though there is a large literature reporting Amerindian haplogroups (Carvajal-Carmona et al, 2003;Gomez-Carballa et al, 2012;Kashani et al, 2012;Kolman & Bermingham, 1997;Martinez-Cortes et al, 2013;Mizuno et al, 2014;Rickards, Martinez-Labarga, Lum, De Stefano, & Cann, 1999;Sandoval et al, 2009;Sans, Figueiro, & Hidalgo, 2012;Santos, Ward, & Barrantes, 1994), no study before us has determined if haplogroup affects longevity in an Amerindian-derived population. A cross-cultural and biocultural approach to the study of the link between longevity and mtDNA haplogroups demands the inclusion of diverse populations.…”