Résumé
The primary Afrotropical malaria mosquito vector Anopheles gambiae sensu
stricto has a complex population structure. In western Africa, this
species is split into two molecular forms and displays local and regional
variation in chromosomal arrangements and behaviours. To investigate
patterns of macro-geographic population substructure, 25 An. gambiae
samples from 12 African countries were genotyped at 13 microsatellite
loci. This analysis detected the presence of additional population
structuring, with the M-form being subdivided into distinct west, central
and southern African genetic clusters. These clusters are coincident with
the central African rainforest belt and northern and southern savannah
biomes, which suggests restrictions to gene flow associated with the
transition between these biomes. By contrast geographically patterned
population substructure appears much weaker within the S-form.