Expression of cuticular protein genes, BmorCPG11 and BMWCP5 is differently regulated at the pre-pupal stage in wing discs of Bombyx mori.

Through BLAST search of the genomic database of Bombyx mori, we found a clone, BmorCPG11, which has only putative BR-C binding sites in the 2 kb upstream region. Both BmorCPG11 and BR-Z2 were expressed in the cephalic region of the epidermis, differently from BR-Z1 and BR-Z4. BR-Z2 transcripts increased by the addition of 20-hydroxyl-ecdysone (20E), which was slightly inhibited by cycloheximide. BmorCPG11 expression was also induced by the addition of 20E, which was inhibited by cycloheximide. Both BmorCPG11 and BR-Z2 were induced by the 20E pulse treatment, but they were inhibited by the addition of cycloheximide. Both genes showed similar expression pattern in wing discs during the developmental stage and in vitro ecdysone responsiveness, and both showed relatedness. The result of a reporter assay demonstrated the strong relatedness of BmorCPG11 and BR-Z2. The expression profiles of BmorCPG11 and BR-Z2 are different from those of BMWCP5 and βFTZ-F1. The present findings showed different regulation of cuticular protein genes by ecdysone-responsive transcription factors at the pre-pupal stage of wing discs of B. mori.