Investigating genetic diversity in admixed populations from Ecuador

Abstract

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 FSTs, 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 R2 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.

Population-Specific Distribution of TPMT Deficiency Variants and Ancestry Proportions in Ecuadorian Ethnic Groups: Towards Personalized Medicine

“…57 Within the studied ethnic groups, the MEZ population exhibits a intricate genetic structure resulting from varying admixture patterns involving European, African, and Native American populations. [58][59][60][61] These findings, coupled with the F ST divergence analysis, substantiate the heterogeneity of the studied population and emphasize that the significant genetic variability observed among Ecuadorian ethnic groups not only underscores cultural distinctions but also underscores genetic diversity. 62 The TPMT variants we have described offer a comprehensive genetic characterization of the studied ethnic groups, particularly considering the allele distribution within the MEZ, IND, and AFE groups.…”

Estimations of Mutation Rates Depend on Population Allele Frequency Distribution: The Case of Autosomal Microsatellites

“…Microsatellites (or short tandem repeats (STRs)) have been widely used in a wide range of scientific fields, such as population and forensic genetics, anthropology, and evolution; see, for example, [ 1 , 2 , 3 ]. For most of these usages, a critical parameter is required: the (germinal) mutation rate, that is, the frequency of errors in replicating DNA when producing a gamete.…”

Genetic Variability in the E6/E7 Region of Human Papillomavirus 16 in Women from Ecuador

“…The higher prevalence of HPV16 lineage D may be related to factors such as the ethnic composition of the population. This suggests the possibility that the distribution of this lineage in the littoral region may be related to historical links and migrations within the country, and it deserves future studies including human genetic markers [ 34 ].…”