Y-chromosome DNA haplotypes in Basques

One Y-specific DNA polymorphism (p49/TaqI) was studied in a sample of 97 French Basques and compared with those found in 7 other French, Iberian, and Italian populations. A particularly high frequency (72.2%) of Y-haplotype XV was observed in Basques, compared to values (mean of 41%) obtained in other Western Europeans. Basques were also characterized by virtual absence, or presence at a low level, of the South or Near Eastern haplotypes XII, VII, and VIII. Considered together, these results confirm that Basques are a very ancient European population which has had little previous contact with the Neolithics.     

Digital dermatoglyphics in the Basque population: univariate and multivariate comparison with other Spanish populations

We have analyzed dermatoglyphic finger patterns in a Spanish Basque population (841 males and 911 females). Bimanual and sexual comparisons have been carried out by means of contingency analysis. The results in the Basque population are compared with those of other Spanish populations, based on univariate (chi 2 contingency test and Student's t-test) and multivariate (principal components analyses) statistical methods. Bilateral distribution asymmetry and sexual dimorphism were observed in the Basque sample. The results of the chi 2 test for pattern types in males and females show statistically significant differences between the Basques and other Spanish populations, with the exception of the males from El Bierzo. Comparing populations with regard to the Pattern Intensity Index, the differences observed are much lower; therefore, this confirms what other authors have suggested regarding the limited usefulness of indexes in populational comparisons. In the Caucasian variation range of pattern types, Basques are located in the high part with regard to arches, in the low part with regard to whorls and radial loops, and in an intermediate part in relation to ulnar loops and overall pattern intensity. Results of the multivariate comparisons show which populations are more or less distant from the Basque population and which variables are significant in contributing to these population relationships.     

DNA polymorphisms detect ancient barriers to gene flow in Basques

This work features the first district-by-district analysis of all provinces in the Iberian Peninsula with an autochthonous Basque population, and indicates the existence of genetic heterogeneity. The populations cluster in three groups arising from processes of genetic drift which probably occurred in pre-Mesolithic times, and were probably those which repopulated the southern areas of the Basque Country after the Last Glacial Maximum. It seems that from that period onwards, the population settled in three major groups (West Basques, Central Basques, and East Basques), along geographical axes which appear substantial in the maintaining of each population unit. This genetic structure is probably reflected in other aspects such as the existence of ancient tribes and the dialects of the Basque language, the boundaries of which may be related at origin and which are quite similar to those detected in this work. Our results indicate that the populations of the Basque Country are genetically close to other neighboring populations, such as that of Aragon, which may indicate an outgoing gene flow from the Basque area down the River Ebro towards the Mediterranean seaboard. While our short tandem repeat data suggest that population structure within the Basques dates back to the Mesolithic, our findings are also consistent with the hypothesis that patterns of modern European genetic diversity have been shaped mainly during the Neolithic.     

Genetic hematology of french basques: recent data about this peculiar pyrenean people

The Basques demonstrate marked specificities regarding language, genetics and culture among all European populations. They live at the Western end of the Pyrenees along the Atlantic Ocean and are thought to represent the descendants of the Upper-Palaeolithic men. We have investigated French Basques for several genetic hematology markers including hemotypology (ABO and Rhesus groups) and inherited diseases such as genetic hemochromatosis (iron overload mainly related to the C282Y mutation), factor V Leiden (the most important inherited prothrombotic risk factor among Europeans) and coagulation factors deficiency. We found that this population has vonserved its peculiar hemotypology profile described many decades ago but with interprovince heterogeneity. The C282Y mutation was less prevalent than in European neighbouring populations and we noted a quasi-absence of factor V Leiden. In contrast, an unusual high frequency of factor XI deficiency (a rare coagulation condition worldwide) was evidenced and associated with the still unpublished Cys38Arg mutation, this finding being suggestive of a founder effect. Our results, interpreted in the view of population genetics, could contribute to a better understanding of the history of the Basque people.     

Genetic Structure of the French Red Squirrel Populations: Implication for Conservation

The decline of the red squirrel (Sciurus vulgaris) in several European countries due to the introduction of the American grey squirrel (S. carolinensis) and the predicted arrival of the grey squirrel in France in the near future has lead to the development of a preventative conservation project in this country. In this study, we conducted an extensive survey of mitochondrial DNA variation in French red squirrels using a fragment of the mitochondrial D-loop and we compared the results with previously published data from other European populations. Our main aims were: (1) to determine whether genetically differentiated populations, which could represent prioritized units for conservation purposes, were present in France and (2) to determine whether the French population, which is currently largely undisturbed, could provide information on the postglacial recolonization history of the species. We found that French D-loop haplotypes show almost no tendency to cluster by geographic origin, be it region or country, suggesting that French red squirrels have not been isolated from other populations during an evolutionarily significant period and that they do not constitute an Evolutionary Significant Unit. The French red squirrels showed strong signals of population expansion, the opposite to what is observed in most other European populations, making them of particular interest to study the postglacial expansion history of the species.     

Properdin factor B polymorphism in continental Italy and Sardinia

Summary A sample of healthy unrelated individuals (882 from Continental Italy and Sicily, and 139 from Sardinia) were typed for HLA and Bf polymorphisms. Bf gene frequencies in Continental Italy and Sicily show an intermediate position among European populations, with Lapps on one side and Basques on the other side; while a very peculiar pattern is observed among Sardinians, with an impressive similarity with French Basques and with the highest F1 gene frequency so far observed. The HLA: Bf gametic associations in Italy and Sardinia are also reported, which confirm the different ethnic background of these populations.This work was supported by Centro di Immunogenetica ed Istocompatibilità, C.N.R., Torino, Italy and by a grant of Ministero Pubblica Istruzione (M.P.I., Cap. 8551/1980).     

Distinct invasion sources of common ragweed <Emphasis Type="Italic">(Ambrosia artemisiifolia)</Emphasis> in Eastern and Western Europe

The common ragweed (Ambrosia artemisiifolia L.; Asteraceae) is a North American native that is invading Eurasia. Besides its economic impact on crop yield, it presents a major health problem because of its highly allergenic pollen. The plant was imported inadvertently to Europe in the eighteenth century and has become invasive in several countries. By analyzing French and North American populations, it was previously shown that French populations were best described as a mixture of native sources and that range expansion in France probably involved sequential bottlenecks. Here, our aim was to determine whether Eastern European populations of A. artemisiifolia originated from the previously established French populations or from independent trans-Atlantic colonization events. We used nuclear microsatellite markers to elucidate the relationships among populations from Eastern and Western Europe in relation to populations from a broad survey across the native North American range. We found that A. artemisiifolia from Eastern Europe did not originate from the earlier established French populations but rather represents multiple independent introductions from other sources, or introductions from a not yet identified highly diverse native population. Eastern European populations show comparable amounts of genetic variability as do previously characterized French and North American populations, but analyses of population structure clearly distinguish the two European groups. This suggests separate introductions in Eastern and Western Europe as well as divergent sources for these two invasions, possibly as a result of distinct rules for trade and exchange for Eastern Europe during most of the twentieth century.     

A genome-wide survey does not show the genetic distinctiveness of Basques

Basques are a cultural isolate, and, according to mainly allele frequencies of classical polymorphisms, also a genetic isolate. We investigated the differentiation of Spanish Basques from the rest of Iberian populations by means of a dense, genome-wide SNP array. We found that F _ST distances between Spanish Basques and other populations were similar to those between pairs of non-Basque populations. The same result is found in a PCA of individuals, showing a general distinction between Iberians and other South Europeans independently of being Basques. Pathogen-mediated natural selection may be responsible for the high differentiation previously reported for Basques at very specific genes such as ABO, RH, and HLA. Thus, Basques cannot be considered a genetic outlier under a general genome scope and interpretations on their origin may have to be revised.     

Mitochondrial DNA in Basque descendants from the city of Trinidad, Uruguay: Uruguayan- or Basque-like population?

Like other countries in the Americas, during its colonization Uruguay was the recipient of immigrants from several ethnic groups from Europe, as well as of enslaved Africans. After its independence in 1830, Basques were the first group of Europeans to arrive in the country. In this paper, we aim to contribute to the understanding of the process of integration of these migratory waves into the Uruguayan society. For that purpose, individuals of Basque origin from the city of Trinidad, Uruguay, were chosen to participate in this study. Particularly, we wanted to determine if Basque descendants in Uruguay remained relatively isolated or if they mixed with other ethnic groups. Mitochondrial DNA (mtDNA) of 60 self-identified Basque descendants, taken from a larger sample of subjects with Basque ancestors, was analyzed. The origin of mtDNA haplogroups was 77.8% European, 20.4% Amerindian, and 1.8% African, showing similar frequencies to other Uruguayan regions. Very few sequences showed a clear Basque origin, although other sources such as the Canary Islands are likely. Moreover, genetic distances clearly show that Basque descendants are genetically closer to other Uruguayan groups than to European populations, including Basques. It is possible to conclude that Basques and their descendants in the region of Trinidad did not remain isolated and that their marriage behavior was similar to that of other Uruguayan populations. However, to have a more accurate picture of the way Basques intermarried with other populations in Uruguay, new analyses are needed that take into account paternal lineages as well as biparental genetic markers.     

The Basques according to polymorphic Alu insertions

Polymorphic Alu insertions provide a set of DNA markers of interest in human population genetics. Approximately 1000-2000 of these insertions have not reached fixation within the human genome. Each one of these polymorphic loci most probably resulted from a unique insertional event, and therefore all individuals possessing the insertion are related by descent not just state. In addition, the direction of mutational change is toward the gain of the Alu element at a particular locus. Therefore, the improved knowledge of both the ancestral state and the direction of mutational change greatly facilitates the analysis of population relationships. As a result, Alu insertion polymorphisms represent a significant tool for population genetic studies. In this study, polymorphic Alu insertions have been employed to ascertain phylogenetic relationships among Basque groups and worldwide populations. The Basques are considered to be a geographic isolate with a unique language and customs. They may be direct descendants of Cro-Magnon enclaves from the upper Paleolithic (38,000 to 10,000 years). The Basques are distributed among narrow valleys in northeastern Spain with little migration between them until recently. This characteristic may have had an effect on allelic frequency distributions. With the aim of studying this possible effect, we have analyzed six autosomal polymorphic Alu loci from four different sites within the Spanish Basque region in order to ascertain any genetic heterogeneity among the Basques. The results are consistent with a lack of homogeneity among these four autochthonous Basque groups.     

Twenty nuclear DNA polymorphisms in a Moroccan population: a comparison with seven other human populations

A south central Moroccan sample was analyzed for 20 nuclear DNA polymorphisms (restriction fragment length polymorphisms). The population was chosen on the basis of available information on its history, making it suitable for comparisons with data from other European populations. The markers analyzed have been studied previously in several human groups from different continents, and data on African and European samples have been compared to evaluate the genetic affinity of the studied sample with other populations, especially with two Spanish groups: Basques and Andalusians. Heterozygosity levels showed intermediate values between the African and European groups and higher than those found so far in an African group for the studied markers. Genetic distances closely matched geographical relationships through neighbor-joining tree and correspondence analysis, the Moroccans being closer to the European groups than the sub-Saharan Africans included in the analysis. Allele distributions revealed specific population associations with large weight of several alleles in the differentiation of some groups. Gene flow from sub-Saharan Africa appears to be relevant in understanding the differentiation of present Moroccan populations.     

Evidence of Pre-Roman Tribal Genetic Structure in Basques from Uniparentally Inherited Markers

Basque people have received considerable attention from anthropologists, geneticists, and linguists during the last century due to the singularity of their language and to other cultural and biological characteristics. Despite the multidisciplinary efforts performed to address the questions of the origin, uniqueness, and heterogeneity of Basques, the genetic studies performed up to now have suffered from a weak study design where populations are not analyzed in an adequate geographic and population context. To address the former questions and to overcome these design limitations, we have analyzed the uniparentally inherited markers (Y chromosome and mitochondrial DNA) of ～900 individuals from 18 populations, including those where Basque is currently spoken and populations from adjacent regions where Basque might have been spoken in historical times. Our results indicate that Basque-speaking populations fall within the genetic Western European gene pool, that they are similar to geographically surrounding non-Basque populations, and also that their genetic uniqueness is based on a lower amount of external influences compared with other Iberians and French populations. Our data suggest that the genetic heterogeneity and structure observed in the Basque region result from pre-Roman tribal structure related to geography and might be linked to the increased complexity of emerging societies during the Bronze Age. The rough overlap of the pre-Roman tribe location and the current dialect limits support the notion that the environmental diversity in the region has played a recurrent role in cultural differentiation and ethnogenesis at different time periods.     

Georgian and kurd mtDNA sequence analysis shows a lack of correlation between languages and female genetic lineages

Mitochondrial DNA sequences from Georgians and Kurds were analyzed in order to test the possible correlation between female lineages and languages in these two neighboring West Eurasian groups. Mitochondrial sequence pools in both populations are very similar despite their different linguistic and prehistoric backgrounds. Both populations present mtDNA lineages that clearly belong to the European gene pool, as shown by 1) similar nucleotide and sequence diversities; 2) a large number of sequences shared with the rest of European samples; 3) nonsignificant genetic distances; and 4) classification of the present lineages into the major European mtDNA haplogroups already described. The outlier position of the populations from the Caucasus according to classical genetic markers is not recognized in the present Georgian mtDNA sequence pool. This result suggests that the differentiation of mtDNA sequences in West Eurasia and the outlier features of Caucasian populations should be attributed to different processes. Moreover, the putative linguistic relationship between Caucasian groups and the Basques, another outlier population within Europe for classical genetic markers, is not detected by the analysis of mtDNA sequences.     

A FERM-adjacent (FA) region defines a subset of the 4.1 superfamily and is a potential regulator of FERM domain function

Background

It is customary, in population genetics studies, to consider Basques as the direct descendants of the Paleolithic Europeans. However, until now there has been no irrefutable genetic proof to support this supposition. Even studies based on mitochondrial DNA (mtDNA), an ideal molecule for constructing datable maternal genealogies, have failed to achieve this. It could be that incoming gene flow has replaced the Basque ancient lineages but it could also be that these lineages have not been detected due to a lack of resolution of the Basque mtDNA genealogies. To assess this possibility we analyzed here the mtDNA of a large sample of autochthonous Basques using mtDNA genomic sequencing for those lineages that could not be unequivocally classified by diagnostic RFLP analysis and control region (HVSI and HVSII) sequencing.

Results

We show that Basques have the most ancestral phylogeny in Europe for the rare mitochondrial subhaplogroup U8a. Divergence times situate the Basque origin of this lineage in the Upper Palaeolithic. Most probably, their primitive founders came from West Asia. The lack of U8a lineages in Africa points to an European and not a North African route of entrance. Phylogeographic analysis suggest that U8a had two expansion periods in Europe, the first, from a south-western area including the Iberian peninsula and Mediterranean France before 30,000 years ago, and the second, from Central Europe around 15,000–10,000 years ago.

Conclusion

It has been demonstrated, for the first time, that Basques show the oldest lineages in Europe for subhaplogroup U8a. Coalescence times for these lineages suggest their presence in the Basque country since the Upper Paleolithic. The European U8 phylogeography is congruent with the supposition that Basques could have participated in demographic re-expansions to repopulate central Europe in the last interglacial periods.     

The Basques: review of population genetics and Mendelian disorders

The Basques live at the western end of the Pyrenees along the Atlantic Ocean and are thought to represent the descendants of a pre-Neolithic people. They demonstrate marked specificities regarding language and genetics among the European populations. We review the published data on the population genetics and Mendelian disorders of the Basques. An atypical distribution in some blood group polymorphisms (ABO, Rhesus, and Duffy) was first found in this population. Subsequently, additional characteristics have been described with regard to proteins (enzymes and immunoglobulins) and the HLA system. The advent of molecular biology methods in the 1990s allowed further insights into Basque population genetics based mainly on Y-chromosome and mitochondrial DNA. In addition, the Basques demonstrate peculiarities regarding the distribution of various inherited diseases (i.e., unusual frequencies or founding effects). Taken together, these data support the idea of an ancient and still relatively unmixed population subjected to genetic drift.     

THE ORIGIN OF WEST EUROPEAN SUBSPECIES OF HONEYBEES (APIS MELLIFERA): NEW INSIGHTS FROM MICROSATELLITE AND MITOCHONDRIAL DATA

Apis mellifera is composed of three evolutionary branches including mainly African (branch A), western and northern European (branch M), and southeastern European (branch C) populations. The existence of morphological clines extending from the equator to the Polar Circle through Morocco and Spain raised the hypothesis that the branch M originated in Africa. Mitochondrial DNA analysis revealed that branches A and M were characterized by highly diverged lineages implying very remote links between both branches. It also revealed that mtDNA haplotypes from lineages A coexisted with haplotypes M in the Iberian Peninsula and formed a south-north frequency cline, suggesting that this area could be a secondary contact zone between the two branches. By analyzing 11 populations sampled along a France-Spain/Portugal-Morocco-Guinea transect at 8 microsatellite loci and the DraI RFLP of the COI-COII mtDNA marker, we show that Iberian populations do not present any trace of “africanization” and are very similar to French populations when considering microsatellite markers. Therefore, the Iberian Peninsula is not a transition area. The higher haplotype A variability observed in Spanish and Portuguese samples compared to that found in Africa is explained by a higher mutation rate and multiple and recent introductions. Selection appears to be the best explanation to the morphological and allozymic clines and to the diffusion and maintenance of African haplotypes in Spain and Portugal.     

The Expanded mtDNA Phylogeny of the Franco-Cantabrian Region Upholds the Pre-Neolithic Genetic Substrate of Basques

The European genetic landscape has been shaped by several human migrations occurred since Paleolithic times. The accumulation of archaeological records and the concordance of different lines of genetic evidence during the last two decades have triggered an interesting debate concerning the role of ancient settlers from the Franco-Cantabrian region in the postglacial resettlement of Europe. Among the Franco-Cantabrian populations, Basques are regarded as one of the oldest and more intriguing human groups of Europe. Recent data on complete mitochondrial DNA genomes focused on macrohaplogroup R0 revealed that Basques harbor some autochthonous lineages, suggesting a genetic continuity since pre-Neolithic times. However, excluding haplogroup H, the most representative lineage of macrohaplogroup R0, the majority of maternal lineages of this area remains virtually unexplored, so that further refinement of the mtDNA phylogeny based on analyses at the highest level of resolution is crucial for a better understanding of the European prehistory. We thus explored the maternal ancestry of 548 autochthonous individuals from various Franco-Cantabrian populations and sequenced 76 mitogenomes of the most representative lineages. Interestingly, we identified three mtDNA haplogroups, U5b1f, J1c5c1 and V22, that proved to be representative of Franco-Cantabria, notably of the Basque population. The seclusion and diversity of these female genetic lineages support a local origin in the Franco-Cantabrian area during the Mesolithic of southwestern Europe, ∼10,000 years before present (YBP), with signals of expansions at ∼3,500 YBP. These findings provide robust evidence of a partial genetic continuity between contemporary autochthonous populations from the Franco-Cantabrian region, specifically the Basques, and Paleolithic/Mesolithic hunter-gatherer groups. Furthermore, our results raise the current proportion (≈15%) of the Franco-Cantabrian maternal gene pool with a putative pre-Neolithic origin to ≈35%, further supporting the notion of a predominant Paleolithic genetic substrate in extant European populations.     

Microsatellite genetic variation reveals extensive introgression between wild and introduced stocks, and a new evolutionary unit in French pike Esox lucius L.

The genetic variability of 11 French pike Esox lucius populations from rivers or extensive aquaculture ponds was analysed using seven microsatellite markers. The fish stocking of eastern European pike in French rivers is widespread, so five supplementary populations from this region were also analysed. Genetic variability within the French population was small, and similar to that previously found in Europe for this species. French populations from stocked rivers and extensive farms formed a genetically homogeneous group, and did not diverge from most eastern European samples, which may reflect either ancestral polymorphism or a complete introgression of French populations by introduced stocks. Bayesian analysis of the admixture between populations enabled identification of the French populations that were likely to be affected by introduced stocks (of local or foreign origin). Three genetically distinct evolutionary branches were identified: continental Europe, Danube basin, and south‐western France. The last is a new finding in the species which needs to be further explored by comparisons with wild populations at other sites.