High genetic differentiation between the M and S molecular forms of Anopheles gambiae in Africa.
BACKGROUND
Anopheles gambiae, a major vector of malaria, is widely distributed throughout sub-Saharan Africa. In an attempt to eliminate infective mosquitoes, researchers are trying to develop transgenic strains that are refractory to the Plasmodium parasite. Before any release of transgenic mosquitoes can be envisaged, we need an accurate picture of the differentiation between the two molecular forms of An. gambiae, termed M and S, which are of uncertain taxonomic status.


RESULTS
Insertion patterns of three transposable elements (TEs) were determined in populations from Benin, Burkina Faso, Cameroon, Ghana, Ivory Coast, Madagascar, Mali, Mozambique, Niger, and Tanzania, using Transposon Display, a TE-anchored strategy based on Amplified Fragment Length Polymorphism. The results reveal a clear differentiation between the M and S forms, whatever their geographical origin, suggesting an incipient speciation process.


CONCLUSIONS
Any attempt to control the transmission of malaria by An. gambiae using either conventional or novel technologies must take the M/S genetic differentiation into account. In addition, we localized three TE insertion sites that were present either in every individual or at a high frequency in the M molecular form. These sites were found to be located outside the chromosomal regions that are suspected of involvement in the speciation event between the two forms. This suggests that these chromosomal regions are either larger than previously thought, or there are additional differentiated genomic regions interspersed with undifferentiated regions.
Esnault
Caroline
C
Laboratoire de Biométrie et Biologie Evolutive (UMR 5558), CNRS, Université de Lyon, Université Lyon1, Villeurbanne, France.
Boulesteix
Matthieu
M
Duchemin
Jean Bernard
JB
Koffi
Alphonsine A
AA
Chandre
Fabrice
F
Dabiré
Roch
R
Robert
Vincent
V
Simard
Frédéric
F
Tripet
Frédéric
F
Donnelly
Martin J
MJ
Fontenille
Didier
D
Biémont
Christian
C
D000349:Africa; D000818:Animals; D030801:Animals, Genetically Modified; D000852:Anopheles / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D009033:Culicidae / Q000378:metabolism; D004251:DNA Transposable Elements; D008954:Models, Biological; D008957:Models, Genetic; D010802:Phylogeny; D010961:Plasmodium / Q000378:metabolism; D011110:Polymorphism, Genetic; D025341:Principal Component Analysis; D013045:Species Specificity; D019076:Transgenes
D004251:DNA Transposable Elements