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Investigating genetic diversity in admixed populations from Ecuador
Author(s) -
FloresEspinoza Rodrigo,
PazCruz Elius,
RuizPozo Viviana A.,
LopezCarrera Marcelo,
CabreraAndrade Alejandro,
Gusmão Leonor,
Burgos German
Publication year - 2021
Publication title -
american journal of physical anthropology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.146
H-Index - 119
eISSN - 1096-8644
pISSN - 0002-9483
DOI - 10.1002/ajpa.24341
Subject(s) - population , gene flow , demography , genetic admixture , geography , amazon rainforest , biology , genetic diversity , ancestry informative marker , allele frequency , ecology , genetics , allele , gene , sociology
Objectives According to demographic history, Ecuador has experienced shifts in its Native American populations caused by European colonization and the African slave trade. The continuous admixture events among Europeans, Native Americans, and Africans occurred differently in each region of the country, producing a stratified population. Thus, the aim of this study was to investigate the level of genetic substructure in the Ecuadorian Mestizo population. Materials and methods A total of 377 male and 209 female samples were genotyped for two sets of X‐chromosomal markers (32 X‐Indels and 12 X‐STRs). Population analyses performed included Hardy–Weinberg equilibrium tests, LD analysis, PCA, pairwise F ST s, and AMOVA. Results Significant levels of LD were observed between markers separated by distances of less than 1 cM, as well as between markers separated by distances varying from 10.891 to 163.53 cM. Among Ecuadorian regions, Amazonia showed the highest average R 2 value. Discussion When X‐chromosomal and autosomal differentiation values were compared, a sex‐biased admixture between European men and Native American and African women was revealed, as well as between African men and Native American women. Moreover, a distinct Native American ancestry was discernible in the Amazonian population, in addition to sex‐biased gene flow between Amazonia and the Andes and Pacific coast regions. Overall, these results underline the importance of integrating X chromosome information to achieve a more comprehensive view of the genetic and demographic histories of South American admixed populations.