Mitochondrial Haplogroup U5b3: A Distant Echo of the Epipaleolithic in Italy and the Legacy of the Early Sardinians

Dipartimento di Genetica e Microbiologia, Università di Pavia, Pavia, Italy.
The American Journal of Human Genetics (Impact Factor: 10.93). 07/2009; 84(6):814-21. DOI: 10.1016/j.ajhg.2009.05.004
Source: PubMed


There are extensive data indicating that some glacial refuge zones of southern Europe (Franco-Cantabria, Balkans, and Ukraine) were major genetic sources for the human recolonization of the continent at the beginning of the Holocene. Intriguingly, there is no genetic evidence that the refuge area located in the Italian Peninsula contributed to this process. Here we show, through phylogeographic analyses of mitochondrial DNA (mtDNA) variation performed at the highest level of molecular resolution (52 entire mitochondrial genomes), that the most likely homeland for U5b3-a haplogroup present at a very low frequency across Europe-was the Italian Peninsula. In contrast to mtDNA haplogroups that expanded from other refugia, the Holocene expansion of haplogroup U5b3 toward the North was restricted by the Alps and occurred only along the Mediterranean coasts, mainly toward nearby Provence (southern France). From there, approximately 7,000-9,000 years ago, a subclade of this haplogroup moved to Sardinia, possibly as a result of the obsidian trade that linked the two regions, leaving a distinctive signature in the modern people of the island. This scenario strikingly matches the age, distribution, and postulated geographic source of a Sardinian Y chromosome haplogroup (I2a2-M26), a paradigmatic case in the European context of a founder event marking both female and male lineages.

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    • "ns . Mitochon - drial DNA variation is usually more stratified in populations owed to its low ( female ) effective population size compare to autosomes ( already commented in Salas et al . [ 2009 ] ) . Population sub - structure is very well documented in the literature on human population genetics , even at small and regional scales ( e . g . , [ Pala et al . , 2009 ; Catelli et al . , 2011 ; Gó mez - Carballa et al . , 2012 ; Marcheco - Teruel et al . , 2014 ] ) . On the other hand , the review of the literature carried out in the present study tentatively suggests that journals are generally more permissive with the methodology and the statistical procedures employed in case - control disease stu"
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