title: Genes encoding two essential DNA replication activation proteins, Cdc6 and Mcm3, exhibit very different patterns of expression in the tobacco BY-2 cell cycle.
abstract: Very little is known about the expression patterns in plants of genes that encode proteins involved in the initiation of DNA replication. Partial cDNA sequences that encode Cdc6 and Mcm3 in tobacco have been isolated. The sequences were used as probes in northern blots which suggested that, in the cell cycle of synchronized tobacco BY-2 cells, expression of CDC6 is confined to late G(1) and S-phase whereas the expression of MCM3 is not confined to any particular cell cycle phase. These data were confirmed and extended by real-time PCR measurements of mRNA abundance through the cell cycle. CDC6 exhibits a very clear peak of expression in S-phase whereas MCM3, expressed at a much lower level than CDC6, is not cell-cycle-regulated. These patterns of cell cycle gene expression resemble those found in the fission yeast Schizosaccharomyces pombe rather than those in budding yeast or mammalian cells.
authors.affiliation: School of Biological Sciences, Washington Singer Laboratories, University of Exeter, Exeter EX4 4QG, UK.
authors.forename: Gerardas
authors.initials: G
authors.lastname: Dambrauskas
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Aves
authors.forename: John A
authors.initials: JA
authors.lastname: Bryant
authors.forename: Dennis
authors.initials: D
authors.lastname: Francis
authors.forename: Hilary J
authors.initials: HJ
authors.lastname: Rogers
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D004261:DNA Replication / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000166:cytology / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D005966:Glucuronidase