title: Allelic-specific expression in relation to Bombyx mori resistance to Bt toxin.
abstract: Understanding the mechanism of Bt resistance is one of the key elements of the effective application of Bt in pest control. The lepidopteran model insect, the silkworm, demonstrates qualities that make it an ideal species to use in achieving this understanding. We screened 45 strains of silkworm (Bombyx mori) using a Cry1Ab toxin variant. The sensitivity levels of the strains varied over a wide range. A resistant strain (P50) and a phylogenetically related susceptible strain (Dazao) were selected to profile the expressions of 12 Bt resistance-related genes. The SNPs in these genes were detected based on EST analysis and were validated by allelic-specific PCR. A comparison of allelic-specific expression between P50 and Dazao showed that the transcript levels of heterozygous genes containing two alleles rather than an imbalanced allelic expression contribute more to the resistance of P50 against Bt. The responses of the allelic-specific expression to Bt in hybrid larvae were then investigated. The results showed that the gene expression pattern of an ATP-binding cassette transporter C2 (ABCC2) and an aminopeptidase N (APN3), changed in an allelic-specific manner, with the increase of the resistant allele expression correlated with larval survival. The results suggest that a trans-regulatory mechanism in ABCC2 and APN3 allelic-specific expression is involved in the insect's response to the Bt toxin. The potential role of allelic-specific gene regulation in insect resistance to Bt toxins is discussed.
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Sericultural Research Institute, Jiangsu University of Science and Technology, Zhengjiang 212018, Jiangsu, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhengjiang 212018, Jiangsu, China.
authors.forename: Muwang
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Iftakher
authors.initials: I
authors.lastname: Islam
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Lang
authors.initials: L
authors.lastname: You
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yueqiang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ling
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Baosheng
authors.initials: B
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: tananjiang@sippe.ac.cn.
authors.forename: Anjiang
authors.initials: A
authors.lastname: Tan
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000483:Alleles; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D012831:Bombyx / Q000187:drug effects* / Q000235:genetics*; D018826:CD13 Antigens; D004731:Endotoxins / Q000494:pharmacology*; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000494:pharmacology*; D007305:Insecticide Resistance / Q000235:genetics; D007814:Larva / Q000187:drug effects; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide
chemical_list: D018528:ATP-Binding Cassette Transporters; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D018826:CD13 Antigens
keywords: Allelic-specific expression; Bombyx mori; Bt toxin; Insect resistance; SNPs; trans-regulatory