January 19, 2005

Y-chromosome variation in Azores (II)

Following a very recent paper on Y-chromosomal variation in the Azores, a new study deals with the subject of difference in different islands of the Azores, reflecting different patterns of settlement. Unfortunately, as the authors acknowledge, the level of phylogenetic resolution used by this study is insuficient to resolve the fraction of origin of the population from Portugal, other European countries, Jews, North and Sub-Saharan Africans.

Ann Hum Genet (Online Early)

Analysis of Y-chromosome Variability and its Comparison with mtDNA Variability Reveals Different Demographic Histories Between Islands in the Azores Archipelago (Portugal)

R. Montiel et al.

Summary

We determined the Y-chromosomal composition of the population of the Azores Islands (Portugal), by analyzing 20 binary polymorphisms located in the non-recombining portion of the Y-chromosome (NRY), in 185 unrelated individuals from the three groups of islands forming the Archipelago (Eastern, Central and Western). Similar to that described for other Portuguese samples, the most frequent haplogroups were R1(xR1b3f) (55.1%), E(xE3a) (13%) and J (8.6%). Principal components analysis revealed a Western European profile for the Azorean population. No significant differences between Azores and mainland Portugal were observed. However, the haplogroup distribution across the three groups of islands was not similar (P<0.003). The Western group presented differences in the frequencies of haplogroups R1, E(xE3a) and I1b2 (27.3%, 22.7% and 13.6%, respectively) when compared to the other two groups. An assessment of the NRY variability, and its comparison with mitochondrial DNA (mtDNA) variability, was further evidence of the differential composition of males during the settlement of the three groups of islands, contrary to what has been previously deduced for the female settlers using mtDNA data.

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1 comment:

Dutra said...

The Western islands of the Azores were colonized originally by the Flemish while looking for silver. This is the origin of the i1 component.