Population structure of the malaria vector Anopheles moucheti in the equatorial forest region of Africa

Christophe Antonio-Nkondjio¹ , Cyrille Ndo¹^,3 , Pierre Kengne² , Louis Mukwaya⁴ , Parfait Awono-Ambene¹ , Didier Fontenille² and Frédéric Simard¹^,2

¹Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la Lutte contre les Endémies en Afrique Centrale (OCEAC), P.O. Box 288, Yaoundé, Cameroon

²Laboratoire de lutte contre les Insectes Nuisibles, Institut de Recherche pour le Développement (IRD), UR 016, 911, avenue Agropolis, P.O. Box 64501, 34394 Montpellier cedex 5, France

³Faculty of Sciences, University of Yaoundé I, P.O. Box 337, Yaoundé, Cameroon

⁴Entomology Division, Uganda Virus Research Institute, P.O. Box 49, Entebbe, Uganda

author email corresponding author email

Malaria Journal 2008, 7:120doi:10.1186/1475-2875-7-120


Published:	4 July 2008

Abstract

Background

Anopheles moucheti is a major malaria vector in forested areas of Africa. However, despite its important epidemiological role, it remains poorly known and insufficiently studied. Here, levels of genetic differentiation were estimated between different A. moucheti populations sampled throughout its distribution range in Central Africa.

Methods

Polymorphism at ten microsatellite markers was compared in mosquitoes sampled in Cameroon, the Democratic Republic of Congo and an island on Lake Victoria in Uganda. Microsatellite data were used to estimate genetic diversity within populations, their relative long-term effective population size, and the level of genetic differentiation between them.

Results

All specimens collected in Tsakalakuku (Democratic Republic of Congo) were identified as A. m. bervoetsi while other samples consisted of A. m. moucheti. Successful amplification was obtained at all microsatellite loci within all A. m. moucheti samples while only six loci amplified in A. m. bervoetsi. Allelic richness and heterozygosity were high for all populations except the island population of Uganda and A. m. bervoetsi. High levels of genetic differentiation were recorded between A. m. bervoetsi and each A. m. moucheti sample as well as between the island population of A. m. moucheti and mainland populations. Significant isolation by distance was evidenced between mainland populations.

Conclusion

High levels of genetic differentiation supports complete speciation of A. m. bervoetsi which should henceforth be recognized as a full species and named A. bervoetsi. Isolation by distance is the main force driving differentiation between mainland populations of A. m. moucheti. Genetically and geographically isolated populations exist on Lake Victoria islands, which might serve as relevant field sites for evaluation of innovative vector control strategies.