Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/26239
Title: Stability of Culex quinquefasciatus resistance to Bacillus sphaericus evaluated by molecular tools
Authors: Amorim, Liliane Barbosa
Barros, Rosineide Arruda de
Chalegre, Karlos Diogo de Melo
Oliveira, Cláudia Maria Fontes de
Regis, Lêda Narcisa
Silva-Filha, Maria Helena Neves Lobo
Affilliation: Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.
Abstract: Bacillus sphaericus binary toxin action on Culex quinquefasciatus larvae relies on the binding to Cqm1alpha-glucosidases, which act as midgut receptors. Resistance of two laboratory-selected colonies is associated with the allele cqm1(REC) that prevents Cqm1 expression as membrane-bound molecules. This study evaluated stability of resistance after the interruption of selection pressure and introduction of susceptible individuals in these colonies. Bioassays showed that frequency of resistant larvae did not decrease throughout 11 generations, under these conditions, and it was associated to a similar frequency of larvae lacking the Cqm1alpha-glucosidase receptor, detected by in gel enzymatic assays. Direct screening of the cqm1(REC) allele, by specific PCR, showed that its frequency remained stable throughout 11 generations. Parental resistant colony did not display biological costs regarding fecundity, fertility and pupal weight and data from susceptibility assays, enzymatic assays and PCR screening showed that cqm1(REC) was not disfavored in competition with the susceptible allele and persisted in the progenies, in the lack of selection pressure. Characterization of molecular basis of resistance is essential for developing diagnostic tools and data have relevant implication for the establishment of strategies for resistance management.
Keywords: Binary toxin
Cqm1
α-Glucosidade
Resistance allele
PCR
Fitness cost
keywords: Toxina binária
Cqm1
α-Glucosidade
Alelo de resistência
PCR
Custo de fitness
DeCS: Alelos
Animais
Bacilo / fisiologia
Culex / genética
Culex / imunologia
Culex / microbiologia
Fêmea
Interações Host-Pathogen
Imunidade Inata
Proteínas de Insetos / genética
Masculino
Reação em Cadeia da Polimerase
alfa-glucosidases / genética
Issue Date: 2010
Publisher: Elsevier
Citation: AMORIM, L. B. et al. Stability of Culex quinquefasciatus resistance to Bacillus sphaericus evaluated by molecular tools. Insect Biochemistry and Molecular Biology, v. 40, n. 4, p. 311–316, abr. 2010.
DOI: 10.1016/j.ibmb.2010.02.002
ISSN: 1879-0240
Copyright: restricted access
Appears in Collections:PE - IAM - Artigos de Periódicos

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