title: Toxicological, Biochemical, and Histopathological Analyses Demonstrating That Cry1C and Cry2A Are Not Toxic to Larvae of the Honeybee, Apis mellifera.
abstract: The honey bee, Apis mellifera, is commonly used as a test species for the regulatory risk assessment of insect-resistant genetically engineered (IRGE) plants. In the current study, a dietary exposure assay was developed, validated, and used to assess the potential toxicity of Cry1C and Cry2A proteins from Bacillus thuringiensis (Bt) to A. mellifera larvae; Cry1C and Cry2A are produced by different IRGE crops. The assay, which uses the soybean trypsin inhibitor (SBTI) as a positive control and bovine serum albumin (BSA) as a negative control, was used to measure the responses of A. mellifera larvae to high concentrations of Cry1C and Cry2A. Survival was reduced and development was delayed when larvae were fed SBTI (1 mg/g diet) but were unaffected when larvae were fed BSA (400 μg/g), Cry1C (50 μg/g), or Cry2A (400 μg/g). The enzymatic activities of A. mellifera larvae were not altered and their midgut brush border membranes (BBMs) were not damaged after being fed with diets containing BSA, Cry1C, or Cry2A; however, enzymatic activities were increased and BBMs were damaged when diets contained SBTI. The study confirms that Cry1C and Cry2A have no acute toxicity to A. mellifera larvae at concentrations >10 times higher than those detected in pollen from Bt plants.
authors.affiliation: †State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, People's Republic of China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Wang
authors.affiliation: †State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, People's Republic of China.
authors.forename: Yun-He
authors.initials: YH
authors.lastname: Li
authors.affiliation: ‡Department of Entomology, Michigan State University, East Lansing, Michigan, United States.
authors.forename: Zachary Y
authors.initials: ZY
authors.lastname: Huang
authors.affiliation: †State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, People's Republic of China.
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Chen
authors.affiliation: †State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, People's Republic of China.|§Agroscope, Institute for Sustainability Sciences ISS, 8046 Zurich, Switzerland.
authors.forename: Jörg
authors.initials: J
authors.lastname: Romeis
authors.affiliation: ∥Key Laboratory of Pollinating Insect Biology of Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing 100093, People's Republic of China.
authors.forename: Ping-Li
authors.initials: PL
authors.lastname: Dai
authors.affiliation: †State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, People's Republic of China.
authors.forename: Yu-Fa
authors.initials: YF
authors.lastname: Peng
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D001516:Bees / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development; D001681:Biological Assay; D004731:Endotoxins / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000633:toxicity*; D007814:Larva / Q000737:chemistry* / Q000187:drug effects / Q000254:growth & development
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: SBTI; environmental risk assessment; in vitro; nontarget effects; tier 1 study