Representative samples of gene clusters based on microarray data. Several clusters included genes that are up-regulated (A) or down-regulated (B) in pupae, or induced (C) or repressed (D) by feeding. Lines connect expression levels for each gene but are not meant to imply a linear change between biological states. Expression values are processed, normalized, and log2-transformed microarray data for whole juvenile stages or midguts and fat bodies of adults. See Additional file 3: Table S3 for gene names.