Gene Expression Response of the Spruce Budworm, Choristoneura fumiferana, after Exposure to Various Doses of Bacillus thuringiensis Cry1Ab Toxin Using Microarray Technology

In order to gain more insight into the response of the North American lepidopteran forest pest Choristoneura fumiferana to the Cry1Ab toxin of Bacillus thuringiensis, linearly amplified mRNA was synthesized from midguts of healthy and infected insects exposed to various sublethal doses of this toxin. Fluorescently labeled cDNAs obtained from the mRNA were hybridized onto a custom DNA microarray chip containing 1091 clones isolated from a subtractive library between toxin-fed and control insects. Our results show that genes implicated in various metabolic functions were specifically enhanced or repressed when susceptible larvae were exposed to sublethal doses of toxin.