title: A coleopteran cadherin fragment synergizes toxicity of Bacillus thuringiensis toxins Cry3Aa, Cry3Bb, and Cry8Ca against lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae).
abstract: The lesser mealworm, Alphitobius diaperinus, is a serious cosmopolitan pest of commercial poultry facilities because of its involvement in structural damage to poultry houses, reduction in feed conversion efficiency, and transfer of avian and human pathogens. Cry3Aa, Cry3Bb, and Cry8Ca insecticidal proteins of Bacillus thuringiensis are used to control coleopteran larvae. Cadherins localized in the midgut epithelium function as receptors for Cry toxins in lepidopteran, coleopteran, and dipteran insects. Previously, we demonstrated that the truncated cadherin (DvCad1) from Diabrotica virgifera virgifera, which consists of the C-terminal cadherin repeats (CR) 8-10 and expressed in Escherichia coli, enhanced Cry3Aa and Cry3Bb toxicity against several coleopteran species. Here we report that the DvCad1-CR8-10 enhances Cry3Aa, Cry3Bb, and Cry8Ca toxicity to lesser mealworm. Previously, by an enzyme linked immunosorbent microplate assay, we demonstrated that the DvCad1-CR8-10 binds activated-Cry3Aa (11.8 nM), -Cry3Bb (1.4nM), and now report that CR8-10 binds activated-Cry8Ca (5.7 nM) toxin. The extent of Cry toxins enhancement by DvCad1-CR8-10, which ranged from 3.30- to 5.93-fold, may have practical application for lesser mealworm control in preventing avian and human pathogen transfer in poultry facilities.
authors.affiliation: Department of Entomology, University of Georgia, Athens, GA 30602-2603, United States.
authors.forename: Youngjin
authors.initials: Y
authors.lastname: Park
authors.affiliation: Department of Entomology, University of Georgia, Athens, GA 30602-2603, United States.
authors.forename: Gang
authors.initials: G
authors.lastname: Hua
authors.affiliation: Department of Entomology, University of Georgia, Athens, GA 30602-2603, United States.
authors.forename: Milton D
authors.initials: MD
authors.lastname: Taylor
authors.affiliation: Department of Entomology, University of Georgia, Athens, GA 30602-2603, United States; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602-2603, United States. Electronic address: adang@uga.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Adang
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D001517:Coleoptera; D004731:Endotoxins / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000633:toxicity*; D019476:Insect Proteins / Q000378:metabolism / Q000633:toxicity*; D010572:Pest Control, Biological / Q000379:methods*; D013712:Tenebrio / Q000187:drug effects
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; C507666:Cry3Bbl endotoxin, Bacillus thuringiensis; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Bacillus thuringiensis; Cadherin; Cry toxin; Lesser mealworm; Synergists