Publications des scientifiques de l'IRD

Ayala Diego, Fontaine M. C., Cohuet Anna, Fontenille Didier, Vitalis R., Simard Frédéric. (2011). Chromosomal inversions, natural selection and adaptation in the malaria vector Anopheles funestus. Molecular Biology and Evolution, 28 (1), p. 745-758. ISSN 0737-4038.

Titre du document
Chromosomal inversions, natural selection and adaptation in the malaria vector Anopheles funestus
Année de publication
2011
Type de document
Article référencé dans le Web of Science WOS:000285418600070
Auteurs
Ayala Diego, Fontaine M. C., Cohuet Anna, Fontenille Didier, Vitalis R., Simard Frédéric
Source
Molecular Biology and Evolution, 2011, 28 (1), p. 745-758 ISSN 0737-4038
Chromosomal polymorphisms, such as inversions, are presumably involved in the rapid adaptation of populations to local environmental conditions. Reduced recombination between alternative arrangements in heterozygotes may protect sets of locally adapted genes, promoting ecological divergence and potentially leading to reproductive isolation and speciation. Through a comparative analysis of chromosomal inversions and microsatellite marker polymorphisms, we hereby present biological evidence that strengthens this view in the mosquito Anopheles funestus s.s, one of the most important and widespread malaria vectors in Africa. Specimens were collected across a wide range of geographical, ecological, and climatic conditions in Cameroon. We observed a sharp contrast between population structure measured at neutral microsatellite markers and at chromosomal inversions. Microsatellite data detected only a weak signal for population structuring among geographical zones (F-ST < 0.013, P < 0.01). By contrast, strong differentiation among ecological zones was revealed by chromosomal inversions (F-ST > 0.190, P < 0.01). Using standardized estimates of F-ST, we show that inversions behave at odds with neutral expectations strongly suggesting a role of environmental selection in shaping their distribution. We further demonstrate through canonical correspondence analysis that heterogeneity in eco-geographical variables measured at specimen sampling sites explained 89% of chromosomal variance in A. funestus. These results are in agreement with a role of chromosomal inversions in ecotypic adaptation in this species. We argue that this widespread mosquito represents an interesting model system for the study of chromosomal speciation mechanisms and should provide ample opportunity for comparative studies on the evolution of reproductive isolation and speciation in major human malaria vectors.
Plan de classement
Entomologie médicale / Parasitologie / Virologie [052]
Description Géographique
CAMEROUN
Localisation
Fonds IRD [F B010080119]
Identifiant IRD
fdi:010080119
Contact