Summary
The replication of F′ lac was studied in exponentially growing cultures of E. coli B/r. The cells were pulse induced for the synthesis of β-galactosidase and their DNA pulse labelled with 3H thymidine. The cells were then separated into age classes by centrifugation through a sucrose gradient in a zonal rotor. Plasmid replication was measured in each age fraction by three methods: the rate at which β-galactosidase could be induced, the amount of label incorporated into CCC plasmid DNA which had been separated from chromosomal DNA on agarose gels, and the amount of label incorporated into plasmid DNA which had been separated from chromosomal DNA by ultracentrifugation through CsCl-EtBr gradients. All these methods gave the same result, that replication of F′ lac occurs in cells of all ages and is not confined to a part of the cell cycle.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abbo, F.E., Pardee, A.B.: Synthesis of macromolecules in synchronously dividing bacteria. Biochim. biophys. Acta (Amst.) 39, 478–485 (1960)
Bachmann, B.J., Low, K.B., Taylor, A.L.: Recalibrated linkage map of Escherichia coli K12. Bact. Rev. 40, 116–166 (1976)
Beck, B.D., Park, J.T.: Activity of three murein hydrolases during the cell division cycle of Escherichia coli K12 as measured in toluenetreated cells. J. Bact. 126, 1250–1260 (1976)
Clark, D.J.: The regulation of DNA replication and cell division in Escherichia coli B/r. Cold Spr. Harb. Symp. quant. Biol. 33, 823–836 (1968)
Clewell, D.B., Helinski, D.R.: Supercoiled circular DNA-protein complexes in Escherichia coli: Purification and induced conversion to open circular DNA form. Proc. nat. Acad. Sci. (Wash.) 62, 1159–1166 (1969)
Cooper, S.: Relationship of F lac replication and chromosome replication. Proc. nat. Acad. Sci. (Wash.) 69, 2706–2710 (1972)
Cooper, S., Helmstetter, c.E.: Chromosome replication and the division cycle of Escherichia coli B/r. J. molec. Biol. 31, 519–540 (1968)
Davis, D.B., Helmstetter, C.E.: Control of F lac replication in Escherichia coli B/r. J. Bact. 114, 294–299 (1973)
Donachie, W.D.: Relationship between cell size and the time of initiation of DNA replication. Nature (Lond.) 219, 1077–1079 (1968)
Donachie, W.D., Masters, M.: Evidence for polarity of chromosome replication in F- strains of Eschericha coli. Genet. Res. 8, 119–124 (1966)
Finkelstein, M., Helmstetter, C.E.: Cell cycle analysis of F′ lac replication in Escherichia coli B/r. J. Bact. 132, 884–895 (1977)
Frame, R., Bishop, J.O.: The number of sex-factors per chromosome in Escherichia coli. Biochem. J. 121, 93–103 (1971)
Gustafsson, P., Nordström, K.: Selection and timing of replication of plasmids R1 drd19 and F′ lac in Escherichia coli. Plasmid 1, 187–203 (1978)
Helmstetter, C.E.: Rate of DNA synthesis during the division cycle of Escherichia coli B/r. J. molec. Biol. 24, 417–427 (1967)
Helmstetter, C.E., Pierucci, O.: Cell division during inhibition of DNA synthesis in Escherichia coli. J. Bact 95, 1627–1633 (1968)
Masters, M.: Origin and direction of replication of the chromosome of Escherichia coli B/r. Proc. nat. Acad. Sci. (Wash.) 65, 601–608 (1970)
Meyers, J.A., Sanchez, D., Elwell, L.P., Falkow, S.: Simple agarose gel electrophoresis method for the identification and characterization of plasmid DNA. J. Bact. 127, 1529–1537 (1976)
Moore, B.A.: Protein synthesis during the cell cycle of Escheria coli. Ph.D. Thesis, Edinburgh University (1976)
Nishi, A., Horiuchi, T.: β-galactosidase formation controlled by an episomal gene during the cell cycle of Escherichia coli. J. Biochem. (Tokyo) 60, 338–340 (1966)
Pritchard, R.H., Barth, P.T., Collins, J.: Control of DNA synthesis in bacteria. Symp. Soc. gen. Microbiol. 19, 263–297 (1969)
Pritchard, R.H., Chandler, M.G., Collins, J.: Independence of F replication and chromosome replication in Escherichia coli. Molec. gen. Genet. 138, 143–155 (1975)
Sharp, P.A., Sugden, J., Sambrook, J.: Detection of two restriction endonuclease activites in haemophilus parainfluenzae using analytical agarose ethidium bromide electrophoresis. Biochem. 12, 3055–3063 (1973)
Smith, T.F., Sadler, J.R.: The nature of lactose operator constitutive mutants. J. molec. Biol. 59, 273–305 (1971)
Thompson, R., Hughes, S., Broda, P.: Plasmid identification using specific endonucleases. Molec. gen. Genet. 133, 141–149 (1974)
Zeuthen, J., Pato, M.L.: Replication of the F′ lac sex factor in the cell cycle of Escherichia coli. Molec. gen. Genet. 111, 242–255 (1971)
Author information
Authors and Affiliations
Additional information
Communicated by Ch. Auerbach
Rights and permissions
About this article
Cite this article
Andresdottir, V., Masters, M. Evidence that F′ lac replicates asynchronously during the cell cycle of Escherichia coli B/r. Molec. Gen. Genet. 163, 205–212 (1978). https://doi.org/10.1007/BF00267411
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00267411