Alterations in the expression of certain midgut genes of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) larvae and midgut histopathology in response to Bacillus thuringiensis Cry1C toxin

Abstract Background Bacillus thuringiensis ( Bt ) utilization as a biological control agent is highly recommended due to its safety, specificity, and efficiency. Importance of the entomocidal Cry proteins secreted by dramatically increased subsequent genes transformation into number economic crops, rendering them protection against insect attack. In last decade, resistance transgenic crops gradually raised in several lepidopteran pests. A better understanding processing Cry1C toxin larval midgut pest species, cotton leaf worm, Spodoptera littoralis (Boisd.), very important characterize main regulatory elements tolerance. Results The present study aimed define factors that are involved tolerance toward through evaluating mRNA level trypsin (Try), aminopeptidase N (APN), alkaline phosphatase (ALP), cadherin (Cad), cytochrome P450 (CYP) both susceptible cry1C tolerant strains S. . Total RNAs were extracted from construct cDNAs. Quantitative real-time polymerase chain reaction (qPCR) showed significant upregulation CYP gene strain. contrast, levels expression Try, ALP, Cad significantly downregulated APN relative did not show differences between strains. Histologically, late third-instar larvae population vacuolization epithelium disruption peritrophic membrane striated boarder compared Conclusions Obtained data indicated relationship exposing alteration CYP, These results may be an evidence for roles development toxicity useful further illustrating