title: KDR mutation, a genetic marker to assess events of introgression between the molecular M and S forms of Anopheles gambiae (Diptera: Culicidae) in the tropical savannah area of West Africa.
abstract: A sodium channel 'kdr'-type mutation was identified in the M form of Anopheles gambiae from Burkina Faso in the tropical savannah area belt. The molecular M form of An. gambiae is found at high frequencies in the flooded rice cultivation area of Kou Valley, where the insecticide selection pressure is limited. The spread of the mutation in the M population is an ongoing process, as it increased from a frequency of 0.006 in 1999 to 0.02 in 2000. The S molecular form occurs in sympatry in our study village, with the M form at a relatively low frequency. The common 'kdr' mutation was previously detected in this area in the S form, and has probably invaded the M population through genetic introgression. This impacts on the question of actual levels of gene flow between the two molecular forms in tropical savannah areas. A hybrid M/S individual was identified during the course of this study, which was homozygous for the 'kdr' mutation. Pyrethroid resistant An. gambiae were caught in October and November, which is the time of year that the molecular S form migrates into this area as rain-fed breeding sites in the cotton fields dry out.
authors.affiliation: Laboratoire de Parasitologie et d'Entomologie du Centre Muraz BP 390 Bobo-Dioulasso, Burkina Faso. a_diabate@hotmail.com
authors.forename: Abdoulaye
authors.initials: A
authors.lastname: Diabate
authors.forename: Thierry
authors.initials: T
authors.lastname: Baldet
authors.forename: Chandre
authors.initials: C
authors.lastname: Chandre
authors.forename: Koumbor Roch
authors.initials: KR
authors.lastname: Dabire
authors.forename: Pierre
authors.initials: P
authors.lastname: Kengne
authors.forename: Tinga Robert
authors.initials: TR
authors.lastname: Guiguemde
authors.forename: Frederic
authors.initials: F
authors.lastname: Simard
authors.forename: Pierre
authors.initials: P
authors.lastname: Guillet
authors.forename: Janet
authors.initials: J
authors.lastname: Hemingway
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Hougard
mesh_terms: D000354:Africa, Western; D000818:Animals; D000852:Anopheles / Q000145:classification / Q000235:genetics*; D002050:Burkina Faso; D005819:Genetic Markers; D005843:Geography; D009154:Mutation; D020033:Protein Isoforms / Q000235:genetics; D015222:Sodium Channels / Q000235:genetics*; D014329:Tropical Climate
chemical_list: D005819:Genetic Markers; D020033:Protein Isoforms; D015222:Sodium Channels