Skip to main content
SpringerLink
Log in

Evidence for a four micron replication unit in CHO cells

  • Published:
Chromosoma Aims and scope Submit manuscript

Abstract

CHO cells in culture were synchronized by mitotic selection, allowed to reattach to plastic flasks, and reach S phase in the presence of fluorodeoxyuridine at concentrations known to completely block the synthesis of thymidylate. The cells were released from the block with 3H-thymidine for pulses of 4, 8, 12, 24 and 40 min and DNA fiber autoradiographs prepared. An analysis of the spacing between origins of replication indicates that sites are available at intervals of about 4 μm along most of the DNA. Chain growth proceeds at about 1,000 nucleotides per minute and some of the closely situated sites become continuous, labeled segments after 8–12 min. However, unlabeled segments are still present between the replicated segments after 40 min. The data may be interpreted as evidence for regularly spaced initiation sites which are available in CHO cells, even though only one in 10–15 of these may be utilized for initiation each cycle under normal growth conditions in these cultures.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Adegoke, J.A.: Programming of DNA synthesis and nature of DNA synthesized at different times in the S phase of the cell cycle of a eukaryotic system. Thesis, Florida State Univ. (1974)

  • Amaldi, F., Carnevalli, F., Leoni, L., Mariotti, D.: Replicon origins in Chinese hamster cell DNA. Exp. Cell Res. 74, 367–374 (1972)

    Google Scholar 

  • Blumenthal, A.B., Kriegstein, H.J., Hogness, D.S.: The units of DNA replication in Drosophila melanogaster chromosomes. Cold Spr. Harb. Symp. quant. Biol. 38, 205–223 (1974)

    Google Scholar 

  • Cairns, J.: Autoradiography of HeLa cell DNA. J. molec. Biol. 15, 372–373 (1966)

    Google Scholar 

  • Callan, H.G.: Replication of DNA in the chromosomes of eukaryotes. Proc. roy. Soc. B 181, 19–41 (1972)

    Google Scholar 

  • Ham, R.G.: An improved nutrient solution for diploid Chinese hamster and human cell lines. Exp. Cell Res. 29, 515–526 (1963)

    Google Scholar 

  • Hand, R., Tamm, I.: DNA replication: Direction and rate of chain growth in mammalian cells. J. Cell Biol. 58, 410–418 (1973)

    Google Scholar 

  • Hand, R., Tamm, I.: Initiation of DNA replication in mammalian cells and its inhibition by reovirus infection. J. molec. Biol. 82, 175–183 (1974)

    Google Scholar 

  • Hori, T.A., Lark, K.G.: Autoradiographic studies of the replication of satellite DNA in the kangaroo rat. J. molec. Biol. 88, 22–232 (1974)

    Google Scholar 

  • Hori, T.A., Lark, K.G.: Evidence for defined lengths of DNA replication units in satellite DNA from D. ordii. Nature (Lond.) 259, 504–505 (1976)

    Google Scholar 

  • Hozier, J.C., Wu, J.R., Taylor, J.H.: Eucaryotic DNA replication: Pattern of incorporation of pulse labels into replicons. J. Cell Biol. 63, 146a. (1974)

    Google Scholar 

  • Huberman, J.A., Riggs, A.D.: On the mechanism of DNA replication in mammalian chromosomes. J. molec. Biol. 32, 327–341 (1968)

    Google Scholar 

  • Kurek, M.P., Taylor, J.H.: Partial characterization of DNA fragments released from replicating hamster DNA. Exp. Cell Res. (in press)

  • Salzman, N.P., Fareed, G.C., Sebring, E.D., Thoren, M.M.: The mechanism of SV40 DNA replication. Cold Spr. Harb. Symp. quant. Biol. 38, 257–265 (1974)

    Google Scholar 

  • Taylor, J.H.: Asynchronous duplication of chromosomes in cultured cells of Chinese hamster. J. biophys. biochem. Cytol. 7, 455–464 (1960)

    Google Scholar 

  • Taylor, J.H., Adams, A.G., Kurek, M.P.: Replication of DNA in mammalian chromosomes. II. Kinetics of 3H-thymidine incorporation and the isolation and partial characterization of labeled subunits at the growing point. Chromosoma (Berl.) 41, 361–384 (1973)

    Google Scholar 

  • Taylor, J.H., Wu, M., Erickson, L.C., Kurek, M.P.: Replication of DNA in mammalian chromosomes. III. Size and RNA content of Okazaki fragments. Chromosoma (Berl.) 53, 175–189 (1975)

    Google Scholar 

  • Wilson, B.G.: DNA replication in the Amphibia. Chromosoma (Berl.) 51, 213–224 (1975)

    Google Scholar 

  • Wolstenholme, D.R.: Replicating DNA molecules from eggs of Drosophila melanogaster. Chromosoma (Berl.) 43, 1–18 (1973)

    Google Scholar 

Download references

Author information

Author notes

  1. John C. Hozier

    Present address: Max-Planck-Institut für Virusforschung, Spemannstraße 35, D-7400, Tübingen, Germany

Authors and Affiliations

  1. Institute of Molecular Biophysics, The Florida State University, 32306, Tallahassee, Florida, USA

    J. Herbert Taylor & John C. Hozier

Authors
  1. J. Herbert Taylor
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. John C. Hozier
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Taylor, J.H., Hozier, J.C. Evidence for a four micron replication unit in CHO cells. Chromosoma 57, 341–350 (1976). https://doi.org/10.1007/BF00332159

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00332159

Keywords

Search

Navigation