title: Glutamate-gated chloride channel subunit cDNA sequencing of Cochliomyia hominivorax (Diptera: Calliphoridae): cDNA variants and polymorphisms.
abstract: The New World screwworm (NWS) Cochliomyia hominivorax (Coquerel) is one of the major myiasis-causing flies that injures livestock and leads to losses of ~US$ 2.7 billions/year in the Neotropics. Ivermectin (IVM), a macrocyclic lactone (ML), is the most used preventive insecticide for this parasite and targets the glutamate-gated chloride (GLUCLα) channels. Several authors have associated altered GluClα homologues to MLs resistance in invertebrates, although studies about resistance in NWS are limited to other genes. Here, we aimed to characterise the NWS GluClα (ChGluClα) cDNA and to search for alterations associated with IVM resistance in NWS larvae from a bioassay. The open reading frame of the ChGluClα comprised 1,359 bp and encoded a sequence of 452 amino acids. The ChGluClα cDNAs of the bioassay larvae showed different sequences that could be splice variants, which agree with the occurrence of alternative splicing in GluClα homologues. In addition, we found cDNAs with premature stop codons and the K242R SNP, which occurred more frequently in the surviving larvae and was located close to mutation (L256F) involved in ML resistance. Although these alterations were in low frequency, the ChGluClα sequencing will allow further studies to find alterations in the gene of resistant natural populations.
authors.affiliation: Laboratory of Genetics and Animal Evolution, Department of Genetics, Evolution and Bioagents, Center of Molecular Biology and Genetic Engineering (CBMEG), University of Campinas, 6010, Campinas, SP, 13083-875, Brazil, bmml321@gmail.com.
authors.forename: Alberto Moura Mendes
authors.initials: AM
authors.lastname: Lopes
authors.forename: Renato Assis
authors.initials: RA
authors.lastname: de Carvalho
authors.forename: Ana Maria Lima
authors.initials: AM
authors.lastname: de Azeredo-Espin
mesh_terms: D000818:Animals; D001681:Biological Assay; D018118:Chloride Channels / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics*; D004175:Diptera / Q000235:genetics*; D019143:Evolution, Molecular; D007814:Larva; D011110:Polymorphism, Genetic / Q000235:genetics*; D021122:Protein Subunits / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018118:Chloride Channels; D018076:DNA, Complementary; D021122:Protein Subunits; C109777:glutamate-gated chloride channels