We review here what is known about the population structure and evolutionary dynamics of members of the Anopheles gambiae complex with emphasis on the situation in West Africa. First, the importance of the 2nd chromosome inversion polymorphism is demonstrated especially in adaptation to levels of aridity, a major environmental variable in Africa. This affects the distribution of karyotypes on both a macro- and micro-geographic scale as well as temporally Such differentiation leads to karyotypes being differentially effective transmitters of malaria and differentially susceptible to indoor residual spraying of insecticides. Second, we review the evidence that cryptic taxa, especially in An. gambiae s.s., exist. This observation stems from both karyotype studies and molecular studies. it is abundantly clear that West African populations of An. gambiae s.s. are often not panmictic units, with premating factors evidently acting to maintain distinct genetic forms. Third, we review phylogenetic studies that have revealed the presence of introgression between the two most important vectors. An. gambiae and An. arabiensis. This is most evident for the 2nd chromosome inversions. This interpretation of phylogenetic data is consistent with a direct laboratory study indicating inversions in this chromosome are stably maintained in backcrossed populations. All of this information has led to the view that members of the An. gambiae complex are highly variable with an abundance of adaptive genetic variation. This presents a significant challenge to vector control programs designed to reduce malaria in sub-Saharan Africa.
Population structure, speciation, and introgression in the Anopheles gambiae complex / J. R., Powell; Petrarca, Vincenzo; DELLA TORRE, Alessandra; A., Caccone; COLUZZI BARTOCCIONI, Caio Mario. - In: PARASSITOLOGIA. - ISSN 0048-2951. - STAMPA. - 41:1-3(1999), pp. 101-113. (Intervento presentato al convegno Malariology Centenary Conference on the Malaria Challenge After One Hundred Years of Malariology tenutosi a ROME, ITALY nel NOV 16-19, 1998).
Population structure, speciation, and introgression in the Anopheles gambiae complex
PETRARCA, Vincenzo;DELLA TORRE, Alessandra;COLUZZI BARTOCCIONI, Caio Mario
1999
Abstract
We review here what is known about the population structure and evolutionary dynamics of members of the Anopheles gambiae complex with emphasis on the situation in West Africa. First, the importance of the 2nd chromosome inversion polymorphism is demonstrated especially in adaptation to levels of aridity, a major environmental variable in Africa. This affects the distribution of karyotypes on both a macro- and micro-geographic scale as well as temporally Such differentiation leads to karyotypes being differentially effective transmitters of malaria and differentially susceptible to indoor residual spraying of insecticides. Second, we review the evidence that cryptic taxa, especially in An. gambiae s.s., exist. This observation stems from both karyotype studies and molecular studies. it is abundantly clear that West African populations of An. gambiae s.s. are often not panmictic units, with premating factors evidently acting to maintain distinct genetic forms. Third, we review phylogenetic studies that have revealed the presence of introgression between the two most important vectors. An. gambiae and An. arabiensis. This is most evident for the 2nd chromosome inversions. This interpretation of phylogenetic data is consistent with a direct laboratory study indicating inversions in this chromosome are stably maintained in backcrossed populations. All of this information has led to the view that members of the An. gambiae complex are highly variable with an abundance of adaptive genetic variation. This presents a significant challenge to vector control programs designed to reduce malaria in sub-Saharan Africa.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.