Genome Ploidy

  • Nancy J. Trun


Traditionally, ploidy (euploidy) has been defined in eukaryotic cells. A cell containing only one homologue of each chromosome is haploid. Cells containing two homologues of each chromosome are diploid; three homologues, triploid, and so on. By this convention, most bacteria in general, and E. coli in particular, contain one homologue of their single chromosome and are considered to be haploid. However, when the differences in the cell cycles of eukaryotes and prokaryotes are considered, this distinction becomes less clear.


Cell Cycle Daughter Cell Replication Fork Replication Time Chromosome Replication 
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  1. Bialkowska-Hobrzanska, H., and D. T. Denhardt. 1984. The rep mutation. VII. Cloning and analysis of the functional rep gene of Escherichia coli K-12. Gene 28:93–102.PubMedCrossRefGoogle Scholar
  2. Campbell, J. L., and N. Kleckner. 1990. E. coli oriC and the dnaA gene promoter are sequestered from Dam methyltransferase following the passage of the chromosomal replication fork. Cell 62:967–979.PubMedCrossRefGoogle Scholar
  3. Cooper, S., and C. E. Helmstetter. 1968. Chromosome replication and the division cycle of Escherichia coli B/r. J. Mol. Biol. 31:519–540.PubMedCrossRefGoogle Scholar
  4. Donachie, W. D., and A. C. Robinson. 1987. Cell division: Parameters values and the process. In Escherichia coli and Salmonella typhimurium. Cellular and molecular biology. pp. 1578–1593. F. C. Neidhardt, ed. American Society for Microbiology, Washington, D.C.Google Scholar
  5. Hartwell, L. H., and T. A. Weinert. 1989. Checkpoints: Controls that ensure the order of cell cycle events. Science 246:629–634.PubMedCrossRefGoogle Scholar
  6. Helmstetter, C. E. 1987. Timing of synthetic activities in the cell cycle. In Escherichia coli and Salmonella typhimurium. Cellular and Molecular Biology, F. C. Neidhardt, ed., pp. 1594–1605. American Society for Microbiology, Washington, D.C.Google Scholar
  7. Helmstetter, C. E., and S. Cooper. 1968. DNA synthesis during the division cycle of rapidly growing Escherichia coli B/r. J. Mol. Biol. 31:507–518.PubMedCrossRefGoogle Scholar
  8. Kjeldgaard, N. O., O. Maaloe, and M. Schaechter. 1958. The transition between different physiological states during balanced growth of Salmonella typhimurium. J. Gen. Microbiol. 19:607.PubMedGoogle Scholar
  9. Kubitschek, H. E., and C. N. Newman. 1978. Chromosome replication during the division cycle in slowly growing, steady-state cultures of three Escherichia coli B/r strains. J. Bacteriol. 136:179–190.PubMedGoogle Scholar
  10. Lane, H. E., and D. T. Denhardt. 1975. The rep mutation. IV. Slower movement of replication forks in Escherichia coli rep strains. J. Mol. Biol. 97:99–112.PubMedCrossRefGoogle Scholar
  11. LeBowitz, J. H., and R. McMacken. 1986. The Escherichia coli DnaB replication protein is a DNA helicase. J. Biol. Chem. 261:4738–4748.PubMedGoogle Scholar
  12. Lederberg, J., and E. L. Tatum. 1946. Gene recombination in Escherichia coli. Nature 158:558.PubMedCrossRefGoogle Scholar
  13. Levine, A., S. Autret, and S. J. Seror. 1995. A checkpoint involving RTP, the replication terminator protein, arrests replication downstream of the origin during the Stringent Response in Bacillus subtilis. Mol. Microbiol. 15:287–295.PubMedCrossRefGoogle Scholar
  14. Maaloe, O. 1960. The nucleic acids and the control of bacterial growth. In Society for General Microbiology Symposium: Bacterial Genetics: Society for General Microbiology, pp. 272–293.Google Scholar
  15. Maaloe, O., and N. O. Kjeldgaard. 1966. Control of Macromolecular Synthesis (New York: W. A. Benjamin).Google Scholar
  16. Maldonado, R., A. Garzon, D. Dean, and J. Casadesus. 1992. Gene dosage analysis in Azotobacter vinelandii. Genetics 132:869–878.PubMedGoogle Scholar
  17. Maldonado, R., J. Jimenez, and J. Casadesus. 1994. Changes in ploidy during the Azotobacter vinelandii growth cycle. J. Bacteriol. 176:3911–3919.PubMedGoogle Scholar
  18. Murray, A. W., and M. W. Kirschner. 1989. Dominoes and clocks: The union of two views of the cell cycle. Science 246:614–621.PubMedCrossRefGoogle Scholar
  19. Pardee, A. B. 1989. G1 events and regulation of cell proliferation. Science 246:603–608.PubMedCrossRefGoogle Scholar
  20. Sadoff, H. L., B. Shimei, and S. Ellis. 1979. Characterization of Azotobacter vinelandii deoxyribonucleic acid and folded chromosomes. J. Bacteriol. 138:871–877.PubMedGoogle Scholar
  21. Skarstad, K., H. B. Steen, and E. Boye. 1983. Cell cycle parameters of slowly growing Escherichia coli B/r studied by flow cytometry. J. Bacteriol. 154:656–662.PubMedGoogle Scholar
  22. Taucher-Scholz, G., M. Abdel-Monem, and H. Hoffman-Berling. 1983. Functions of DNA helicases in Escherichia coli. In UCLA Symposia on Molecular and Cellular Biology: Mechanisms of DNA replication and recombination, pp. 1–12. N. Cozzarelli, ed. Liss, New York.Google Scholar
  23. Wong, I., M. Amaratunga, and T. M. Lohman. 1993. Heterodimer formation between Escherichia coli Rep and UvrD proteins. J. Biol. Chem. 268:20386–20391.PubMedGoogle Scholar

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© Springer Science+Business Media New York 1998

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  • Nancy J. Trun

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