MOLECULAR MAPPING OF INSECTICIDE RESISTANCE GENES IN THE YELLOW-FEVERMOSQUITO (AEDES-AEGYPTI)

Several loci conferring insecticide resistance in the yellow fever mos quito (Aedes aegypti) have previously been mapped by simple recombinat ional mapping. Here we describe correlation of these resistance phenot ypes with molecular gene probes for insecticide target sites by RFLP m apping. The para sodium channel gene homologue and the GABA receptor g ene Resistance to dieldrin map to the same genome regions as the DDT/p yrethroid and cyclodiene resistance loci, respectively. Although the a cetylcholinesterase (target site of organophosphorus and carbamate ins ecticides) gene Ace does not map to any known resistance locus, it map s very close to the sex-determining locus. We discuss the possibilitie s that, if identified, Ace-mediated resistance in A.aegypti will be se x linked or that, as suggested for anopheline mosquitoes, two independ ent Ace loci may exist, one of which is autosomal. These results suppo rt the importance of target site insensitivity as an insecticide resis tance mechanism in mosquitoes.