The honey bee (Apis mellifera) is naturally widespread throughout Africa, Europe, and Western Asia. Based on morphometric measurements, different subspecies have been identified and grouped into four major evolutionary branches: the A (Africa), M (Western Europe), C (South-Eastern Europe), and O (Middle East) branches. This classification was largely supported by mitochondrial studies, which revealed an additional fifth evolutionary branch, called Y (Yemenitica from Ethiopia; Franck et al., 2001).   

However, controversy still exists over the differentiation of the M branch and the North African A branch populations, and more specifically, over the relationship between the subspecies A. m. intermissa (A branch), A. m. mellifera (M branch from North-Western Europe), and A. m. iberiensis (M branch from Iberian Peninsula). Western Europe and North Africa are contact regions for the A, M, and C evolutionary branches.   

Wing shape analysis through geometric morphometrics does not reflect a clinal transition between the A. m. intermissa, A. m. iberiensis, and A. m. mellifera subspecies. On the contrary, they show a marked break between North African and Western European populations.   

Concerning the presence of African A mitotypes in A. m. iberiensis, the differences detected between Iberian and North African A mitotypes, together with the higher mitotype diversity in Iberia, suggest various introduction events of African mitotypes from different origins or an ancient introduction and subsequent differentiation.

Our results of wing shape and nuclear data did not detect this African influence, indicating that the hypothetical African genetic introgressions seem to have been diluted in the Iberian population.

Finally, our morphometric results assigned individuals to their correct evolutionary branch, even if they had an A lineage mitochondrial haplotype and European M branch nuclear alleles. For this reason, the geometric morphometric methodology applied in this study seems more appropriate than the analysis of mtDNA for the screening and identification of the Africanization process of Central and North American honeybee populations.

SEE:
Both geometric morphometric and microsatellite data consistently support the differentiation of the Apis mellifera M evolutionary branch.  Irati Miguel, et al  Apidologie copyright INRA/DIB-AGIB/EDP Sciences, 2010

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm