A view of the maternal inheritance of Espírito Santo populations: The contrast between the admixed and Pomeranian descent groups

Maternal ancestry and lineages diversity of the Santander population from Colombia

Santander, located in the Andean region of Colombia, is one of the 32 departments of the country. Its population was shaped by intercontinental admixture between autochthonous native Americans, European settlers, and African slaves. To establish forensic databases of haplotype frequencies, the evaluation of population substructure is crucial to capture the genetic diversity in admixed populations. Total control region mitochondrial deoxyribonucleic acid haplotypes were determined for 204 individuals born in the seven provinces across the department. The maternal native heritage is highly preserved in Santander genetic background, with 90% of the haplotypes belonging to haplogroups inside A2, B4, C1, and D. Most native lineages are found broadly across the American continent, while some sub-branches are concentrated in Central America and north South America. Subtle European (6%) and African (4%) input was detected. In pairwise comparisons between provinces, relatively high FST values were found in some cases, although not statistically significant. Nonetheless, when provinces were grouped according to the principal component analysis results, significant differences were detected between groups. The database on mitochondrial deoxyribonucleic acid control region haplotype frequencies established here can be further used for populational and forensic purposes.

Population analysis of complete mitogenomes for 334 samples from El Salvador

The use of mitochondrial DNA (mtDNA) in the field of forensic genetics is widely spread mainly due to its advantages when identifying highly degraded samples. In this sense, massive parallel sequencing has made the analysis of the whole mitogenome more accessible, noticeably increasing the informativeness of mtDNA haplotypes. The civil war (1980-1992) in El Salvador caused many deaths and disappearances (including children) all across the country and the economic and social instability after the war forced many people to emigration. For this reason, different organizations have collected DNA samples from relatives with the aim of identifying missing people. Thus, we present a dataset containing 334 complete mitogenomes from the Salvadoran general population. To the best of our knowledge, this is the first publication of a nationwide forensic-quality complete mitogenome database of any Latin American country. We found 293 different haplotypes, with a random match probability of 0.0041 and 26.6 mean pairwise differences, which is similar to other Latin American populations, and which represent a marked improvement from the values obtained with just control region sequences. These haplotypes belong to 54 different haplogroups, being 91% of them of Native American origin. Over a third (35.9%) of the individuals carried at least a heteroplasmic site (excluding length heteroplasmies). Ultimately, the present database aims to represent mtDNA haplotype diversity in the general Salvadoran populations as a basis for the identification of people that disappeared during or after the civil war.

The Ancestry of Eastern Paraguay: A Typical South American Profile with a Unique Pattern of Admixture

Immigrants from diverse origins have arrived in Paraguay and produced important demographic changes in a territory initially inhabited by indigenous Guarani. Few studies have been performed to estimate the proportion of Native ancestry that is still preserved in Paraguay and the role of females and males in admixture processes. Therefore, 548 individuals from eastern Paraguay were genotyped for three marker sets: mtDNA, Y-SNPs and autosomal AIM-InDels. A genetic homogeneity was found between departments for each set of markers, supported by the demographic data collected, which showed that only 43% of the individuals have the same birthplace as their parents. The results show a sex-biased intermarriage, with higher maternal than paternal Native American ancestry. Within the native mtDNA lineages in Paraguay (87.2% of the total), most haplogroups have a broad distribution across the subcontinent, and only few are concentrated around the Paraná River basin. The frequency distribution of the European paternal lineages in Paraguay (92.2% of the total) showed a major contribution from the Iberian region. In addition to the remaining legacy of the colonial period, the joint analysis of the different types of markers included in this study revealed the impact of post-war migrations on the current genetic background of Paraguay.

Mutational data and population profiling of 23 Y-STRs in three Brazilian populations

Y-chromosomal STRs are important markers in forensic genetics, due to some peculiar characteristics. The absence of recombination makes them a useful tool to infer kinship in complex cases involving distant paternal relatives, or to infer paternal bio-geographic ancestry. The presence of a single copy, being transmitted from father to son, allow tracing mutational events in Y-STRs without ambiguity. For the statistical interpretation of forensic evidences based on Y-STR profiles, it is necessary to have estimates on both mutation rates and haplotype frequencies. In this work, 407 father-son duos from São Paulo and Rio de Janeiro states and 204 unrelated individuals from Manaus were analyzed. Haplotype frequencies and mutation rates for the Y-STRs from the PowerPlex Y23 commercial kit were estimated. Thirty-six mutations were observed in 15 of the 22 Y-STRs analyzed, for an average mutation rate of 3.84 × 10^-3 (95 % CI 2.69 × 10^-3 to 5.32 × 10^-3). All mutations in GAAA repeats occurred in alleles with 13 or more uninterrupted units. Mutations in GATA repeats were observed in alleles with 9-17 uninterrupted units. An analysis carried out in different father's age groups showed an increase of 2.48 times the mutation rate in the age group of 40-50 years, when compared to the 20-30 age group, in agreement with the described for autosomal STRs. A high haplotype diversity was found in the three Brazilian populations. Pairwise genetic distance analysis (F_ST) showed no significant differences between the three populations in this study, which were also close to populations with strong European influence. The highest distances among the Brazilian populations were with São Gabriel da Cachoeira, which has a high Native American ancestry.