Fig. 4

Hormone-degrading enzymes in the midguts. a In the ecdysone metabolic pathway in insects [35, 60], ecdysone that is released from the prothoracic gland cells is either hydroxylated into 20E or metabolized into different intermediate products after oxidization in different tissues. b–c Expression of genes related to ecdysone degradation in the midgut from IV-3:12 h to V-1:0 h. The changes in expression of these genes differed between the two feeding stages according to qRT-PCR assay results. d Detection of ecdysone oxidase and 3-DE 3α-reductase in midguts by Western blot. Antibodies against B. mori ecdysone oxidase and 3-DE 3α-reductase were used for the Western blot assay [33]. Samples are midguts of larvae from IV-3:12 h to V-1:0 h. For each lane, approximately 10 μg was loaded. 3-DE 3α-reductase was observed at each time point. However, large amounts of ecdysone oxidase appeared at the middle time point. e The JH metabolic pathway in insects is based on previous descriptions [41]. f–h Expression of genes involved in JH metabolism in the midgut were assayed by qRT-PCR. These genes were identified in the microarray assay as described above (Fig. 2). These genes were generally up-regulated from the 4th molting stage to the feeding stage as assayed. Each column represents the mean of three independent measurements  ±  S.E.M