Apidologie 38 (2007) 141-155
DOI: 10.1051/apido:2007007

Gene flow within the M evolutionary lineage of Apis mellifera: role of the Pyrenees, isolation by distance and post-glacial re-colonization routes in the western Europe

Irati Miguel^a, Mikel Iriondo^a, Lionel Garnery^b, Walter S. Sheppard^c and Andone Estonba<sup>a

a</sup>  Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country, PO Box 644, 48080 Bilbao, Spain
^b  Laboratoire Population, Génétique et Évolution, CNRS, avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
^c  Department of Entomology, Washington State University, Pullman, WA 99164-6382, USA

(Received 30 December 2005 - Revised 28 July 2006 - Accepted 2 August 2006 - Published online 8 March 2007)

Abstract - We present a population genetic study focused on the two subspecies of the M evolutionary lineage, A. m. mellifera and A. m. iberiensis. Nuclear and mtDNA variation was analysed in 27 bee populations from the Iberian Peninsula, France and Belgium. Microsatellite data provides compelling evidence of a barrier to neutral gene flow at the Pyrenees. In addition, they suggest isolation by distance between populations of the M lineage. Mitochondrial data support the hypothesis that the Iberian Peninsula served as glacial refugia for the honeybees of western Europe. They show two paths of post-glacial re-colonization in the extremes of the Pyrenees and suggest that the western path was more significant in the post-glacial re-colonization process. Thus, we report here on three main factors for mellifera and iberiensis subspecies differentiation: the Pyrenean barrier, isolation by distance and the post-glacial re-colonization process.

Key words: honeybees / subspecies / mtDNA / microsatellite / population genetics

Corresponding author: ggbmimai@lg.ehu.es

© INRA, DIB-AGIB, EDP Sciences 2007