title: Cloning of Cyc (Bmal1) homolog in Bombyx mori: structural analysis and tissue specific distributions.
abstract: Cycle (Bmal1) is one of the circadian clock genes and the key regulator of the circadian system in many organisms, encoding a bHLH-PAS transcription factor. In the present study, we cloned cycle homolog (BmCyc) in Bombyx mori. We performed polymerase chain reaction with degenerated primers deduced from the conserved amino acid sequences of mammalian BMAL1 and Drosophila CYCLE. Then the partial clone obtained was used as a probe for screening a cDNA library constructed from pupal brains of B. mori. BmCyc is 5703 nucleotides long and encodes 700 amino acid residues. The BmCYC has bHLH, PAS A and PAS B domains, and the sequence identities for these domains are 85, 60 and 50%, to Drosophila CYCLE (dCYC) and 69, 58 and 50%, to human BMAL1 (hBMAL1), respectively. The deduced amino acid sequence of BmCYC is 37% identical to that of dCYC and 28% to hBMAL1. Northern blot analysis demonstrates that BmCyc gene was expressed in all the tissues tested, which were head, fat body, silk glands, and midgut. Also no significant day, night time-specific difference in expression of BmCyc gene in the head was detected.
authors.affiliation: Division of Molecular Science, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan. 986d907n@y00.kobe-u.ac.jp
authors.forename: Elitza P
authors.initials: EP
authors.lastname: Markova
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ueda
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Katsutaka
authors.initials: K
authors.lastname: Oishi
authors.forename: Toru
authors.initials: T
authors.lastname: Shimada
authors.forename: Makio
authors.initials: M
authors.lastname: Takeda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D012831:Bombyx / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D015723:Gene Library; D019476:Insect Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D012333:RNA, Messenger; D014157:Transcription Factors