Elsevier

Developmental Biology

Volume 37, Issue 1, March 1974, Pages 117-132
Developmental Biology

5-Bromodeoxyuridine inhibition of differentiation. Kinetics of inhibition and reversal in myoblasts

https://doi.org/10.1016/0012-1606(74)90173-0Get rights and content

Abstract

This paper describes experiments on the kinetics of inhibition of muscle differentiation in vitro in the presence of 5-bromodeoxyuridine (BrdUrd) and the recovery phenomena that occur when such inhibited cells are permitted growth in normal medium. The studies consist of a quantitation of cell fusion in the presence of the analog and during recovery in its absence coupled with simultaneous studies on changes in buoyant density of cellular DNA. We find that if myoblasts are exposed to BrdUrd during the last doubling before cell fusion would normally occur, most cells do not differentiate, but as many as 18% of the cells can fuse in spite of the incorporation of BrdUrd into their nuclei. These nuclei contain approximately the amount of BrdUrd expected for a full round of DNA synthesis. Studies on the rate of recovery of inhibition of cell fusion following one generation in BrdUrd reveal that after one doubling of inhibited cells in the presence of normal medium. fusion reaches about 50% of the control value; after two doublings it reaches 75% of control value; and after 2.5 doublings of reversal, recovery is essentially complete. We find that both the degree of inhibition after approximately one round of BrdUrd incorporation and the rate of cell differentiation after two generations of reversal are consistent with a model which assumes that BrdUrd “sensitivity” resides on single pair of chromosomes and that inhibition occurs in a dominant fashion if approximately 30% or more of the thymidine is replaced by BrdUrd in the readout strand of either chromosome.

References (35)

  • B.M. Paterson et al.

    Myosin synthesis in cultures of differentiating chicken embryo skeletal muscle

    Develop. Biol

    (1972)
  • R. Rownd

    The buoyant density of 5-bromouracil labeled DNA

    Biochim. Biophys. Acta

    (1967)
  • A. Shainberg et al.

    Alterations of enzymatic activities during muscle differentiation in vitro

    Develop. Biol

    (1971)
  • H. Weintraub et al.

    Identification of a developmental program using bromodeoxyuridine

    J. Mol. Biol

    (1972)
  • J. Abbott et al.

    The loss of phenotypic traits by differentiated cells. V. The effects of 5-bromodeoxyuridine on cloned chondrocytes

  • R. Bischoff et al.

    Inhibition of myoblast fusion after one round of DNA synthesis in 5-bromodeoxyuridine

    J. Cell Biol

    (1970)
  • J.R. Coleman et al.

    Muscle differentiation and macromolecular synthesis

    J. Cell. Physiol

    (1968)
  • Cited by (0)

    This work was supported by Grant no. GB 36058 from the National Science Foundation

    1

    Present Address: Department of Biological Sciences, University of Maryland Baltimore Country, 5401 Wilkens Avenue, Baltimore, Maryland 21228.

    View full text