title: Identification and characterization of the DNA replication origin recognition complex gene family in the silkworm Bombyx mori.
abstract: The ORC (origin recognition complex) binds to the DNA replication origin and recruits other replication factors to form the pre-replication complex. The cDNA and genomic sequences of all six subunits of ORC in Bombyx mori (BmORC1-6) were determined by RACE (rapid amplification of cDNA ends) and bioinformatic analysis. The conserved domains were identified in BmOrc1p-6p and the C-terminal of BmOrc6p features a short sequence that may be specific for Lepidoptera. As in other organisms, each of the six BmORC subunits had evolved individually from ancestral genes in early eukaryotes. During embryo development, the six genes were co-regulated, but different ratios of the abundance of mRNAs were observed in 13 tissues of the fifth instar day-6 larvae. Infection by BmNPV (B. mori nucleopolyhedrovirus) initially decreased and then increased the abundance of BmORC. We suggest that some of the BmOrc proteins may have additional functions and that BmOrc proteins participate in the replication of BmNPV.
authors.forename: Hui-Peng
authors.initials: HP
authors.lastname: Yang
authors.affiliation: *The Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 10081, People's Republic of China.
authors.forename: Su-Juan
authors.initials: SJ
authors.lastname: Luo
authors.affiliation: *The Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 10081, People's Republic of China.
authors.forename: Yi-Nü
authors.initials: YN
authors.lastname: Li
authors.affiliation: †Institute of Biochemistry, Zhejiang Sci-Tech University, Hangzhou, Zhejiang Province 310018, People's Republic of China.
authors.forename: Yao-Zhou
authors.initials: YZ
authors.lastname: Zhang
authors.affiliation: *The Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 10081, People's Republic of China.
authors.forename: Zhi-Fang
authors.initials: ZF
authors.lastname: Zhang
mesh_terms: D000818:Animals; D012831:Bombyx / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004261:DNA Replication; D047108:Embryonic Development / Q000235:genetics; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007304:Insect Viruses / Q000235:genetics; D007814:Larva / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018741:Replication Origin; D017422:Sequence Analysis, DNA
chemical_list: D019476:Insect Proteins; D021122:Protein Subunits; D012333:RNA, Messenger