The maternal legacy of Basques in northern navarre: New insights into the mitochondrial DNA diversity of the Franco‐Cantabrian area

Abstract

Autochthonous Basques are thought to be a trace from the human population contraction that occurred during the Last Glacial Maximum, based mainly on the salient frequencies and coalescence ages registered for haplogroups V, H1, and H3 of mitochondrial DNA in current Basque populations. However, variability of the maternal lineages still remains relatively unexplored in an important fraction of the Iberian Basque community. In this study, mitochondrial DNA diversity in Navarre (North Spain) was addressed for the first time. To that end, HVS-I and HVS-II sequences from 110 individuals were examined to identify the most relevant lineages, including analysis of coding region SNPs for the refinement of haplogroup assignment. We found a prominent frequency of subhaplogroup J1c (11.8%) in Navarre, coinciding with previous studies on Basques. Subhaplogroup H2a5, a putative autochthonous Basque lineage, was also observed in Navarre, pointing to a common origin of current Basque geographical groups. In contrast to other Basque subpopulations, comparative analyses at Iberian and European scales revealed a relevant frequency of subhaplogroup H3 (10.9%) and a frequency peak for U5b (15.5%) in Navarre. Furthermore, we observed low frequencies for maternal lineages HV0 and H1 in Navarre relative to other northern Iberian populations. All these findings might be indicative of intense genetic drift episodes generated by population fragmentation in the area of the Franco-Cantabrian refuge until recent times, which could have promoted genetic microdifferentiation between the different Basque subpopulations.

Echoes from Sepharad: signatures on the maternal gene pool of crypto-Jewish descendants

“…69 It also appears with rather high frequencies in Croatia, 70 western Eurasia 71 and the Basque country. 50,72 All U2e individuals in this study belong to the U2e1a1 sub-clade. A high frequency of haplogroup U2 was found in the Braganc¸a Jews (7.0%), whereas in Portugal it only reaches a frequency of 1.3%, being found absent in the Braganc¸a district.…”

“…48 However, the low gene and nucleotide diversities found in this region and in Northern Africa, compared with the ones found in North-Central Europe, seem to exclude Eastern Europe as a possible focus of expansion. 49,50 In the Iberian Peninsula, HV0 is a rare haplogroup, found at low frequencies in NW Spain, Zamora (4.7%), 51 a Spanish province geographically close to Braganc¸a. Because of a lack of resolution, it is not possible to differentiate haplogroup V inside HV0 in the Portuguese population.…”

Ancient mitochondrial lineages support the prehistoric maternal root of Basques in Northern Iberian Peninsula

“…Strikingly, with the exception of T2b, whose frequency peak is located in the North of Italy, 33 subhaplogroups H1 and U5b reach their highest frequencies in the North of the Iberian Peninsula, specifically in the region where the Franco-Cantabrian refuge was settled during the Upper Palaeolithic. 8,34,35 Two subhaplogroups found in Santimamiñe, U5a2a and U3a, are scarce in prehistoric remains and virtually absent in current European populations. However, these haplogroups of the samples S.12N and S.16G are of great interest because they are the most ancient evidence of the presence of subhaplogroups U5a2a and U3a found to date in Western Europe (Supplementary Appendix).…”

“…15,16 This haplotype has been found with a remarkable frequency among numerous populations of the North of the Iberian Peninsula, especially in the Basque area, or in populations of Basque ancestry. 15,35,41,42 In this population sample of Busturialdea 18 individuals (11.39%) were classified into H1j1 subhaplogroup by the analysis of the coding region polymorphism T4733C.…”

Mitochondrial diversity patterns and the Magdalenian resettlement of Europe: new insights from the edge of the Franco-Cantabrian refuge

“…28 These have to be paired with extensive sampling efforts to have a chance of identifying the historic and demographic processes behind the distribution of mtDNA lineages. 29 On that basis, one of the most understudied regions of the peninsula is the Principality of Asturias, which is located precisely in the western edge of the Franco-Cantabrian refuge (Figure 1). …”