Mitochondrial DNA Reveals the Trace of the Ancient Settlers of a Violently Devastated Late Bronze and Iron Ages Village

<div><p>La Hoya (Alava, Basque Country) was one of the most important villages of the Late Bronze and Iron Ages of the north of the Iberian Peninsula, until it was violently devastated around the 4th century and abandoned in the 3rd century B.C. Archaeological evidences suggest that descendants from La Hoya placed their new settlement in a nearby hill, which gave rise to the current village of Laguardia. In this study, we have traced the genetic imprints of the extinct inhabitants of La Hoya through the analysis of maternal lineages. In particular, we have analyzed the mitochondrial DNA (mtDNA) control region of 41 human remains recovered from the archaeological site for comparison with a sample of 51 individuals from the geographically close present-day population of Laguardia, as well as 56 individuals of the general population of the province of Alava, where the archaeological site and Laguardia village are located. MtDNA haplotypes were successfully obtained in 25 out of 41 ancient samples, and 14 different haplotypes were identified. The major mtDNA subhaplogroups observed in La Hoya were H1, H3, J1 and U5, which show a distinctive frequency pattern in the autochthonous populations of the north of the Iberian Peninsula. Approximate Bayesian Computation analysis was performed to test the most likely model for the local demographic history. The results did not sustain a genealogical continuity between Laguardia and La Hoya at the haplotype level, although factors such as sampling effects, recent admixture events, and genetic bottlenecks need to be considered. Likewise, the highly similar subhaplogroup composition detected between La Hoya and Laguardia and Alava populations do not allow us to reject a maternal genetic continuity in the human groups of the area since at least the Iron Age to present times. Broader analyses, based on a larger collection of samples and genetic markers, would be required to study fine-scale population events in these human groups.</p></div

MtDNA haplogroup composition of Laguardia (LG) and Alava (AL) population sample sets.

<p>R0* includes H and HV lineages except for H1, H3, and HV0.</p

Enlarged view of the Basque Country and its provinces with the location of the village of Laguardia and La Hoya archaeological site (distance 1 km).

<p>Enlarged view of the Basque Country and its provinces with the location of the village of Laguardia and La Hoya archaeological site (distance 1 km).</p

Summary of diversity parameters for 51 mtDNA CR (16024–576) sequences from Laguardia and 56 from Alava region.

<p>Insertions at 16193, 309, and 573 were ignored for all calculations.</p

Principal Component Analysis (PCA) based on haplogroup frequencies of La Hoya archaeological samples (LH) and other historic and prehistoric populations from the literature.

<p>Neolithic: Los Cascajos, Navarre (LC); Paternanbidea, Navarre (PA); Camí de Can Grau, Barcelona (C1); San Juan Ante Portam Latinam, Basque Country (SJ). Chalcolitchic: Pico Ramos, Basque Country (PR); Longar, Navarre (LO); El Mirador Cave, Atapuerca (AT). Pre-Roman: Girona, Catalonia (C2). Post-Roman: Aldaieta, Basque Country (AL).</p

Haplogroups identified in the sample set of La Hoya.

<p>N = number of individuals.</p

Genetic polymorphisms of 17 X-STR loci in two Tunisian populations from Sousse and Makthar

Tunisia has a complex demographic history of migrations from within Africa, Europe, and the Middle East. However, only one population study based on X-STR markers has been reported so far. To investigate the genetic polymorphisms of 17 X-STRs in two Tunisian populations from the cities of Sousse and Makthar, and to reveal the genetic relationships with other reference populations. A total of 194 unrelated healthy individuals were analysed for 17 X-STR markers. Our results indicate that DXS6809 is the most polymorphic locus, whereas DXS6807 is the least informative marker in the populations of Sousse and Makthar. In addition, forensic statistical parameters, such as the power of discrimination in males and females, as well as the mean of exclusion in duos and trios, reveal that the panel of 17 X-STRs is highly informative and useful in different forensic applications. Overall, pairwise genetic distances (Fst) and non-metric MDS plots demonstrate clustering of different populations according to their geographic locations and their historical relationships. Overall, the study of X-STR markers of the Tunisian populations can help to promote the establishment of a forensic DNA reference database in Tunisia and provide reference for future anthropological research.</p

Different Evolutionary History for Basque Diaspora Populations in USA and Argentina Unveiled by Mitochondrial DNA Analysis

<div><p>The Basque Diaspora in Western USA and Argentina represents two populations which have maintained strong Basque cultural and social roots in a completely different geographic context. Hence, they provide an exceptional opportunity to study the maternal genetic legacy from the ancestral Basque population and assess the degree of genetic introgression from the host populations in two of the largest Basque communities outside the Basque Country. For this purpose, we analyzed the complete mitochondrial DNA control region of Basque descendants living in Western USA (n = 175) and in Argentina (n = 194). The Diaspora populations studied here displayed a genetic diversity in their European maternal input which was similar to that of the Basque source populations, indicating that not important founder effects would have occurred. Actually, the genetic legacy of the Basque population still prevailed in their present-day maternal pools, by means of a haplogroup distribution similar to the source population characterized by the presence of autochthonous Basque lineages, such as U5b1f1a and J1c5c1. However, introgression of non-Basque lineages, mostly Native American, has been observed in the Diaspora populations, particularly in Argentina, where the quick assimilation of the newcomers would have favored a wider admixture with host populations. In contrast, a longer isolation of the Diaspora groups in USA, because of language and cultural differences, would have limited the introgression of local lineages. This study reveals important differences in the maternal evolutionary histories of these Basque Diaspora populations, which have to be taken into consideration in forensic and medical genetic studies.</p></div

PCA based on mtDNA haplogroup frequencies in Basque Diaspora and European populations.

<p>Haplogroups and subhaplogroups included in the PCA biplot are R0 (including H subhaplogroups), HV0, J*, J1, J2, T*, T1, T2, U*, U1, U2, U3, U4, U5, U5a, U5b, U6, U7, U8, K, I, X, W, N, M, L, A, B, C, D, and others. Populations included are as follows: Basque Diaspora populations (in red) from USA (USA-DDV and USA-DDA) and Argentina (ARG-DDV and ARG-DDA), Basque populations from Spain (BAS) and France (BAF),France (FRA), Germany (GER), Italy (ITA), Portugal (POR), and Spain (non-Basque included) (SPA).</p

Distribution of Eurasian, Native American and African lineages in the Basque Diaspora populations.

<p>Geographical origin of samples is indicated by a number, Boise (1), Reno (2), and Chino (3) from USA, and Buenos Aires province (4) from Argentina. Adapted from Wikimedia Commons (<a href="https://commons.wikimedia.org/wiki/File:America-blank-map-01.svg" target="_blank">https://commons.wikimedia.org/wiki/File:America-blank-map-01.svg</a>); photo of Blank Politic Map of Americas by DavoO, under the Creative Commons Attribution License (CCAL) CC BY 3.0.</p