Production and Characterization of a Subtractive cDNA Library and Quantitative PCR Analysis of Choristoneura fumiferana Genes Differentially Expressed in Response to Bacillus thuringiensis Cry1Ab Toxin Exposure

Bacillus thuringiensis is a biological control agent for Choristoneura fumiferana, exerting its lethal effect primarily through the production of crystal proteins. There is concern about the impact of Cry toxins on non-target species, especially in terms of sublethal effects. By understanding the transcriptional response of C. fumiferana larvae to a sublethal dose of Cry1Ab toxin, we can proceed to assess whether genes showing altered transcriptional profiles can be used as universal Cry toxin stress markers for non-target insects. To this end, a suppression subtraction hybridization library was created and differential mRNA expression of selected clones was measured using a quantitative polymerase chain reaction (Q-PCR) technique