European Journal of Biotechnology and Bioscience

Authors
Md. Saheb Ali, Ahsanul Haque Swapon, Masamitsu Yamaguchi

Abstract
The study was conducted to clarify the expression patterns of Bombyx mori hypothetical cuticular protein genes, CPH1, CPH2 and CPH30 expressed in wing discs at pre-pupal stage. The expression of CPH1 and CPH2 was observed from the W3 early stage and peaked at pupation when the ecdysteroid titer declined. Whereas CPH30 transcripts increased gradually after the beginning of wandering and peaked at W3 late stage and then decreased rapidly from P0 when the ecdysteroid titer decreasing. CPH30 was induced by the ecdysone pulse, and its expression peaked 18h after transfer to a hormone free medium. CPH1 and CPH2 were also induced by the ecdysone pulse, and their expression peaked 24 h after transfer to a hormone free medium. The peak of CPH1 and CPH2 expression was observed later than that of CPH30 both in vivo and In vitro. Genes, CPH1, CPH2 and CPH30 transcripts were not observed after the 20E pulse treatment in the presence of cycloheximide. Transcripts of CPH30 increased by the addition of 20E in V4 wing discs. On contrary, transcripts of CPH1 and CPH2 were not observed after the addition of 20E in V4 wing discs which is different from the case of CPH30. The expression profiles of CPH1 and CPH2 are different from those of CPH30. The present findings suggested different regulation of hypothetical cuticular protein genes at the pre-pupal stage in wing discs of Bombyx mori.