Molecular cloning and characterization of Bombyx mori CREB gene

Abstract

The cAMP response element binding protein (CREB), as one of the best characterized stimulus-induced transcription factors, plays critical roles in activating transcription of target genes in response to a variety of environmental stimuli. To characterize this important molecule in the silkworm, Bombyx mori, we cloned a full-length cDNA of CREB gene from B. mori brains by using RACE-PCR. The sequence of B. mori CREB (named BmCREB1) gene contains a 88 bp 5' UTR, a 783 bp open reading frame (ORF) encoding 261 amino acids and a 348 bp 3' UTR. The deduced BmCREB amino acid sequence has 56.7% and 37.2% homology with CREB from Apis mellifera carnica and Drosophila melanogaster, respectively. The primary structure of the deduced BmCREB1 protein contains a kinase-inducible domain (KID) and a basic region/leucine zipper (bZIP) dimerization domain which exists in all CREB family members. Genomic analysis showed there are 9 exons and 5 introns in B. mori CREB genome sequences. We identified three different isoforms of BmCREB (BmCREB1, BmCREB2 and BmCREB3) through alternative splicing in C terminal. In addition, the expression of BmCREB in different developmental stages was investigated by using quantitative real-time PCR in both diapause and non-diapause type of B. mori bivoltine race (Dazao). BmCREB transcripts showed two peaks in embryonic stage and pupal stage in both types of bivoltine race. However, consistently higher expression of BmCREB was found throughout the developmental stages in the diapause type than in the non-diapause type. These results suggest that BmCREB is involved in the process of diapause induced by environmental factors.

CREB expression in the brains of two closely related parasitic wasp species that differ in long‐term memory formation

“…, 2002). Recently 3 CREB isoforms were described from the brains of the silk moth Bombyx mori caterpillars, and also in this species a single CREB gene was found (Song et al. , 2009).…”

Variations of hydrogen peroxide and catalase expression in Bombyx eggs during diapause initiation and termination

“…The diapause dynamics in this strain are completely controlled by the incubation conditions experienced during maternal embryogenesis. Diapause eggs were obtained as described by Morita et al (2003) and Song et al (2009). Eggs were incubated at 251C under continuous light throughout embryogenesis.…”

Silkmoth chorion gene regulation revisited: promoter architecture as a key player

“…It would not be surprising if the silkmoth C/EBP gene reacted similarly to prostaglandin and was autoregulated by C/EBP and CREB. The silkmoth CREB orthologue produces three isoforms with expression peaks after pupation (Song et al. , 2009), and a typical cAMP response element (TGACGTCA) has been identified in the C/EBP proximal promoter sequence (A. Papantonis and R. Lecanidou, unpubl.…”