A SEX-LINKED ACE GENE, NOT LINKED TO INSENSITIVE ACETYLCHOLINESTERASE-MEDIATED INSECTICIDE RESISTANCE IN CULEX-PIPIENS

An acetylcholinesterase (AChE) gene, Ace.x, showing 93% identity of de duced amino acid sequence to Anopheles stephensi Ace has been cloned f rom a Culex pipiens strain homozygous for insensitive AChE (iAChE) med iated insecticide resistance, DNA sequence of genomic DNA clones ident ified exons 2-5, RFLP of six clones indicated four possible alleles, L inkage analysis located Ace.x to chromosome I, less than 0.8 centimorg ans from the sex locus, whereas the locus conferring resistance was 2. 0 centimorgans from plum-eye on chromosome II. Ace.1 coding for AChE1, which is associated with resistance, is therefore autosomal, We propo se that Ace.x is the recently postulated Ace,a coding for the biochemi cally distinct AChE2, which is not associated with resistance.