Project description:This microarray was used to monitor gene expression in early third-instar larvae of Bt-susceptible O. nubilalis after 6-h feeding on diet with or without Bacillus thuringiensis (Bt) Cry1Ab protoxin.We identified 174 transcripts, for which the expression was changed more than 2-fold in the gut of the larvae fed Cry1Ab protoxin (p<0.05), representing 80 down-regulated and 94 up-regulated transcripts. Among 174 differentially expressed transcripts, 13 transcripts putatively encode proteins that are potentially involved in Bt toxicity, and these transcripts include eight serine proteases, three aminopeptidases, one alkaline phosphatase, and one cadherin.