An ace-1 gene duplication resorbs the fitness cost associated with resistance in Anopheles gambiae, the main malaria mosquito

Benoît S Assogba (1, 2, 3) , Luc Djogbénou (2, 3) , Pascal Milesi (1) , Arnaud Berthomieu (1) , Julie Perez (1) , Diego Ayala (4, 5) , Fabrice Chandre (6, 5) , Michel Makoutodé (2) , Pierrick Labbe (1) , Mylène Weill (1)

1 UMR ISEM - Institut des Sciences de l'Evolution de Montpellier
2 UAC - Université d’Abomey-Calavi = University of Abomey Calavi
3 IRSP - Institut Régional de Santé Publique Comlan Alfred Quenum [Ouidah]
4 MIVEGEC-DEEVA - Diversity, ecology, evolution & Adaptation of arthropod vectors
5 IRD - Institut de Recherche pour le Développement
6 MIVEGEC-VCG - Vector Control Group

Widespread resistance to pyrethroids threatens malaria control in Africa. Consequently, several countries switched to carbamates and organophophates insecticides for indoor residual spraying. However, a mutation in the ace-1 gene conferring resistance to these compounds (ace-1 R allele), is already present. Furthermore, a duplicated allele (ace-1 D) recently appeared; characterizing its selective advantage is mandatory to evaluate the threat. Our data revealed that a unique duplication event, pairing a susceptible and a resistant copy of the ace-1 gene spread through West Africa. Further investigations revealed that, while ace-1 D confers less resistance than ace-1 R , the high fitness cost associated with ace-1 R is almost completely suppressed by the duplication for all traits studied. ace-1 duplication thus represents a permanent heterozygote phenotype, selected, and thus spreading, due to the mosaic nature of mosquito control. It provides malaria mosquito with a new evolutionary path that could hamper resistance management.

Domaines: Evolution [q-bio.PE]; Génétique des populations [q-bio.PE]; Génétique animale

Benoît S Assogba, Luc Djogbénou, Pascal Milesi, Arnaud Berthomieu, Julie Perez, et al.. An ace-1 gene duplication resorbs the fitness cost associated with resistance in Anopheles gambiae, the main malaria mosquito. Scientific Reports, 2015, 5 (1), pp.14529. ⟨10.1038/srep14529⟩. ⟨hal-01938129⟩