Molecular cloning and characterization of Bombyx mori CREB gene


  • ATF

    activating transcription factor


    basic region/leucine zipper


    cAMP response element binding protein of Bombyx mori


    CREB binding protein


    cAMP response element binding protein


    cAMP response element modulator


    diapause hormone


    darkness and low temperature condition


    light and warm temperature condition


    kinase-inducible domain


    polymerase chain reaction

    RT- PCR

    reverse-transcribed polymerase chain reaction


    suboesophageal ganglion


    untranslated region


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 exisits 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 processs of diapause induced by environmental factors. © 2009 Wiley Periodicals, Inc.