Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Scientific Reports - Nature art. 14529 [12 p.] AFRIQUE SUBSAHARIENNE 2015 fdi:010065360 ENG Scientific Reports - Nature 2045-2322 ISI:000362179300001 10.1038/srep14529 https://www.documentation.ird.fr/hor/fdi:010065360 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-10/010065360.pdf 5 Horizon (IRD) 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. 052 UR226 / UR224 Bénin