1. ¹Centre de Recherche, Hôpital Sainte-Justine, Montreal, Quebec, Canada
2. ²Department of Neurology, University of Crete, School of Health Sciences, Heraklion, Crete, Greece
3. ³Centre Hospitalier Régional et Universitaire, Nantes, France
4. ⁴Département de Pédiatrie, Université de Montréal, Montreal, Quebec, Canada
5. ⁵Institute of Human Genetics, Polish Academy of Science, Poznan, Poland

Correspondence: Dr D Labuda, Centre de Recherche, Hôpital Sainte-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec, Canada H3T 1C5. Tel: +1 514 345 4931 ext 3586/3286; Fax: +1 514 345 4731 E-mail: damian.labuda@umontreal.ca

Received 2 May 2003; Revised 4 July 2003; Accepted 4 September 2003; Published online 15 October 2003.

Abstract

Within Europe, classical genetic markers, nuclear autosomal and Y-chromosome DNA polymorphisms display an east–west frequency gradient. This has been taken as evidence for the westward migration of Neolithic farmers from the Middle East. In contrast, most studies of mtDNA variation in Europe and the Middle East have not revealed clinal distributions. Here we report an analysis of dys44 haplotypes, consisting of 35 polymorphisms on an 8 kb segment of the dystrophin gene on Xp21, in a sample of 1203 Eurasian chromosomes. Our results do not show a significant genetic structure in Europe, though when Middle Eastern samples are included a very low but significant genetic structure, rooted in Middle Eastern heterogeneity, is observed. This structure was not correlated to either geography or language, indicating that neither of these factors are a barrier to gene flow within Europe and/or the Middle East. Spatial autocorrelation analysis did not show clinal variation from the Middle East to Europe, though an underlying and ancient east–west cline across the Eurasian continent was detected. Clines provide a strong signal of ancient major population migration(s), and we suggest that the observed cline likely resulted from an ancient, bifurcating migration out of Africa that influenced the colonizing of Europe, Asia and the Americas. Our study reveals that, in addition to settlements from the Near East, Europe has been influenced by other major population movements, such as expansion(s) from Asia, as well as by recent gene flow from within Europe and the Middle East.