| the pyrethroid knock-down resistance gene in the anopheles gambiae complex in mali and further indication of incipient speciation within an. gambiae s.s. | in mali the anopheles gambiae complex consists of an. arabiensis and mopti, savanna and bamako chromosomal forms of an. gambiae s.s. previous chromosomal data suggests a complete reproductive isolation among these forms. sequence analysis of rdna regions led to the characterization of two molecular forms of an. gambiae, named m-form and s-form, which in mali correspond to mopti and to savanna/bamako, respectively, while it has failed so far to show any molecular difference between savanna and ba ... | 2003 | 12752657 |
| spatial distribution of the chromosomal forms of anopheles gambiae in mali. | maps of the distribution of malaria vectors are useful tools for stratification of malaria risk and for selective vector control strategies. although the distribution of members of the anopheles gambiae complex is well documented in africa, a continuous map of the spatial distribution of the chromosomal forms of an. gambiae s.s. is not yet available at country level to support control efforts. | 2008 | 18847463 |
| molecular identification of sympatric chromosomal forms of anopheles gambiae and further evidence of their reproductive isolation. | three chromosomal forms of anopheles gambiae s.s., designated as bamako, mopti and savanna, were studied for diagnostic pcr assays based on the analysis of the x-linked ribosomal dna (rdna). the study was performed on a 1.3 kb fragment containing part of the 28s coding region and part of the intergenic spacer region. the amplified material was cut with fourteen restriction enzymes to detect restriction fragment length polymorphisms (rflps). the enzymes tru9i and hhai produced patterns of dna ban ... | 1997 | 9359579 |
| pcr-based karyotyping of anopheles gambiae inversion 2rj identifies the bamako chromosomal form. | the malaria vector anopheles gambiae is polymorphic for chromosomal inversions on the right arm of chromosome 2 that segregate nonrandomly between assortatively mating populations in west africa. one such inversion, 2rj, is associated with the bamako chromosomal form endemic to southern mali and northern guinea conakry near the niger river. although it exploits a unique ecology and both molecular and chromosomal data suggest reduced gene flow between bamako and other a. gambiae populations, no m ... | 2007 | 17908310 |
| [presence and risk of transmission of wuchereria bancrofti is a reality in rural mali: the case of the town of bariambani in the cirle of kati]. | previous studies on lymphatic filariasis in mali showed high infection rate in rural area. this study was aimed to find wuchereria bancrofti microfilaria in human peripheral blood and larvae in vectors. for that purpose we carried out an entomological, clinical and parasitological study in banambani a village located at 25 km from bamako the capital city. the parasitological and clinical study was a single cross sectional study including night blood thick smear and physical examination. the ento ... | 2006 | 17390523 |
| longitudinal survey of knockdown resistance to pyrethroid (kdr) in mali, west africa, and evidence of its emergence in the bamako form of anopheles gambiae s.s. | studies aimed at monitoring the spread of knockdown resistance to pyrethroids (kdr) in time and space are particularly useful for detecting barriers to gene flow among the chromosomal and molecular forms of anopheles gambiae. we used a recently developed polymerase chain reaction assay to estimate changes in kdr frequency that occurred in several mixed-form populations from mali, west africa, in the past decade. we found that the kdr allele significantly increased in frequency in most population ... | 2007 | 17255234 |
| genetic differentiation between the bamako and savanna chromosomal forms of anopheles gambiae as indicated by amplified fragment length polymorphism analysis. | the main vector of malaria in sub-saharan africa, anopheles gambiae, is subdivided into five chromosomal forms. three of them (i.e., bamako, savanna, and mopti) are found in sympatry in mali, where mopti can be distinguished from the other two forms based on differences in the ribosomal dna locus. however, no molecular markers are available to distinguish bamako from savanna. we examined the banding patterns of 139 amplified fragment length polymorphism primer combinations in an attempt to ident ... | 2006 | 16606999 |
| multilevel analyses of genetic differentiation in anopheles gambiae s.s. reveal patterns of gene flow important for malaria-fighting mosquito projects. | malaria control projects based on the introduction and spread of transgenes into mosquito populations depend on the extent of isolation between those populations. on the basis of the distribution of paracentric inversions, anopheles gambiae has been subdivided into five subspecific chromosomal forms. estimating gene flow between and within these forms of an. gambiae presents a number of challenges. we compared patterns of genetic divergence (f(st)) between sympatric populations of the bamako and ... | 2005 | 15677750 |
| a high malaria reinfection rate in children and young adults living under a low entomological inoculation rate in a periurban area of bamako, mali. | in areas of intense malaria parasite transmission, preliminary studies of the rate of reinfection after curative therapy suggest that small sample size studies of vaccine efficacy are feasible. however, the effect of transmission rate, which may vary considerably between transmission seasons, on reinfection rate has not been assessed in areas of mesoendemicity with seasonal transmission. to address this question, the plasmodium falciparum reinfection rate after curative therapy was measured in s ... | 2002 | 12139226 |
| the distribution and inversion polymorphism of chromosomally recognized taxa of the anopheles gambiae complex in mali, west africa. | data from polytene chromosome studies on the anopheles gambiae complex in mali were reviewed. the banding pattern was successfully scored in 17,705 specimens from 76 sampling sites representing the main ecological strata of the country. two members of the complex, namely an. arabiensis and an. gambiae, were found widespread and frequently sympatric, with the latter prevalent in most localities. population genetic analysis of the inversion polymorphisms indicated the existence of panmictic condit ... | 1998 | 10645562 |
| gametocyte infectivity by direct mosquito feeds in an area of seasonal malaria transmission: implications for bancoumana, mali as a transmission-blocking vaccine site. | infectivity of gametocytemic volunteers living in bancoumana, a village 60 km from bamako, mali, was determined by direct feeds of laboratory-reared anopheles gambiae s. l. gametocytemic adolescents (10-18 years old) were as infectious to mosquitoes as younger volunteers and appear to be a more suitable population for testing transmission-blocking efficacy as compared with adults (> 18 years old). to begin to validate the membrane-feeding assay, sera collected from these same volunteers were sub ... | 1998 | 9749648 |
| mark-release-recapture experiments with anopheles gambiae s.l. in banambani village, mali, to determine population size and structure. | mark-release-recapture experiments with anopheles gambiae s.l. were performed during the wet seasons of 1993 and 1994 in banambani, mali. all recaptured mosquitoes were identified to species by pcr analysis and, when possible, by chromosomal analysis to chromosomal form. two species of the an. gambiae complex were present: an. gambiae s.s. and an. arabiensis; their ratio differed greatly from one year to the next. three chromosomal forms of an. gambiae s.s. were found--bamako, savanna and mopti. ... | 1998 | 9513942 |
| evaluation and optimization of membrane feeding compared to direct feeding as an assay for infectivity. | malaria parasite infectivity to mosquitoes has been measured in a variety of ways and setting, includind direct feeds of and/or membrane feeding blood collected from randomly selected or gametocytemic volunteers. anopheles gambiae s.l is the main vector responsible of plasmodium falciparum transmission in bancoumana and represents about 90% of the laboratory findings, whereas plasmodium malariae and plasmodium ovale together represent only 10%. | 2008 | 19055715 |
| a test of the chromosomal theory of ecotypic speciation in anopheles gambiae. | the role of chromosomal inversions in speciation has long been of interest to evolutionists. recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated with ecotypes that mate assortatively. here, we consider the potential role of paracentric inversions in promoting speciation in a. gambiae via "ecotyp ... | 2008 | 18287019 |
| malaria transmission in relation to rice cultivation in the irrigated sahel of mali. | seven cross-sectional entomological surveys were carried out from september 1995 to february 1998 in three irrigated rice growing villages and three villages without irrigated agriculture in the area surrounding niono, located 350km north-east of bamako, mali. the transmission pattern differed markedly between the two zones. in the irrigated zone, the transmission of malaria was fairly constant over the seasons at a low level. in the non-irrigated zone, transmission was mostly below detection le ... | 2004 | 14732237 |