| chromosomal differentiation and adaptation to human environments in the anopheles gambiae complex. | speciation in the anopheles gambiae complex is reviewed and discussed with emphasis on the patterns of chromosomal differentiation, particularly at the intraspecific level. the significance of inversion polymorphism in gambiae and arabiensis (the two species of greatest medical importance) is evaluated with reference to recent field investigations carried out in nigeria. in both sibling species some of the inversions show clinical geographical changes in frequencies, with evident correlations wi ... | 1979 | 394408 |
| [the anopheles gambiae complex in guinea bissau]. | three species of the anopheles gambiae complex were identified in guinea bissau (west africa) by chromosomal analysis. they were an. melas, an. arabiensis and an. gambiae s.s. an melas was observed in coastal and insular zones of the study area as well as in areas where the rivers are tidal and brackish and bordered by mangroves. for this reason, the species occurs also in inland riverine localities such as farim and bissorà. an. arabiensis apparently occurs only in low numbers in a very limited ... | 1983 | 6543935 |
| control of endophagic anopheles mosquitoes and human malaria in guinea bissau, west africa by permethrin-treated bed nets. | we compared the anti-mosquito and antimalarial potentialities of placebo-treated versus permethrin-impregnated bed nets in north-western guinea bissau. baseline, pre-intervention entomological and parasitological data were collected during the rainy season of 1990 and bed nets were distributed shortly before the rainy season of 1991. pairs of 3 ethnically different villages were investigated. the villages in each pair were at least 2 km apart but belonged to the same ethnic group in an ecologica ... | 1994 | 7886749 |
| anopheles gambiae complex (diptera:culicidae) near bissau city, guinea bissau, west africa. | cytogenetic studies on mosquitoes collected inside bednets near bissau city confirmed the presence of anopheles melas theobald and an. gambiae giles sensu stricto, the latter species prevailing in rainy season samples (approximately 80% in average) and the former in dry season samples (> 90%). seasonal and ecogeographical variations in the frequency of species and chromosomal inversions were analyzed. the analysis of an. gambiae sensu stricto confirmed the existence of the bissau chromosomal for ... | 1996 | 8961643 |
| the palpal ratio method compared with pcr to distinguish between anopheles gambiae s.s. and a. melas from guinea bissau, west africa. | we compared the palpal ratio method with the polymerase chain reaction (pcr) to distinguish between anopheles gambiae s.s. and a. melas. at the end of the rainy season of 1995, female mosquitoes were collected indoors in the antula area of bissau, guinea bissau. a subsample of 354 mosquitoes were identified first with pcr and then with the palpal ratio method (study a). subsequently, another 195 mosquitoes were identified first with the palpal ratio method and then with pcr (study b). the highes ... | 1998 | 9707368 |
| distribution of the members of anopheles gambiae and pyrethroid knock-down resistance gene (kdr) in guinea-bissau, west africa. | an entomological survey conducted in 2002 in guinea bissau aimed i) to study the distribution of the members of anopheles gambiae giles complex (diptera: culicidae) throughout four ecological areas extended from mangrove to savannah ii) to evaluate the insecticide susceptibility status of these malaria vectors exposed to permethrin 0.75% and ddt4%, and finally iii) to investigate the occurrence and the spread of the leu-phe knock down resistance (kdr) gene associated with pyrethroid and ddt resi ... | 2008 | 18543705 |
| high levels of hybridization between molecular forms of anopheles gambiae from guinea bissau. | in the malaria vector anopheles gambiae giles sensu stricto, two molecular forms denoted m and s are considered units of incipient speciation within this species. very low hybrid frequencies and significant genetic differentiation have been found in sympatric m- and s-form populations. we studied the molecular form composition and the degree of genetic differentiation at 15 microsatellites in two samples of an. gambiae collected in two consecutive years from bissau, guinea bissau. high frequenci ... | 2008 | 19058629 |
| Asymmetric introgression between the M and S forms of the malaria vector, Anopheles gambiae, maintains divergence despite extensive hybridization. | The suggestion that genetic divergence can arise and/or be maintained in the face of gene flow has been contentious since first proposed. This controversy and a rarity of good examples have limited our understanding of this process. Partially reproductively isolated taxa have been highlighted as offering unique opportunities for identifying the mechanisms underlying divergence with gene flow. The African malaria vector, Anopheles gambiae s.s., is widely regarded as consisting of two sympatric fo ... | 2011 | 22059383 |
| Morphological Differentiation May Mediate Mate-Choice between Incipient Species of Anopheles gambiae s.s. | The M and S molecular forms of Anopheles gambiae s.s. have been considered incipient species for more than ten years, yet the mechanism underlying assortative mating of these incipient species has remained elusive. The discovery of the importance of harmonic convergence of wing beat frequency in mosquito mating and its relation to wing size have laid the foundation for exploring phenotypic divergence in wing size of wild populations of the two forms. In this study, wings from field collected mos ... | 2011 | 22132169 |