Table 1.

Changes of gene expression in brain and fat body of diapausing pupae compared with expression levels in nondiapausing pupae

	Genes examined	Down-regulation in diapause	Up-regulation in diapause	Equivalent
Brain	60	16 (27%)	16 (27%)	28 (47%)
Fat body	55	33 (60%)	4 (7%)	18 (33%)

Four cDNA libraries constructed from brains and fat body of H. armigera yielded 3,586 genes. RT-PCR was used to monitor expression in 60 selected genes from the brain and 55 selected genes from the fat body. Genes were categorized as being down- or up-regulated in diapause or showing equivalent levels of expression. A 1.5-fold difference in expression was defined as the cutoff for differential expression.