Changes in thymine pool equilibration times during the S phase of mammalian cells

Journal Article · Mon Jan 01 04:00:00 EST 1979 · Exp. Cell Res.; (United States)

DOI:https://doi.org/10.1016/0014-4827(79)90540-8· OSTI ID:5372694

Mattern, M R; Kapp, L N

The thymine precursor pool equilibration times for DNA labelled with (/sup 3/H)thymidine during various parts of S were determined for Chinese hamster ovary (CHO) cells and for the human cell lines HeLa S3 (aneuploid) and E-11 fibroblasts (diploid). Pool equilibration times reached maximum and minimum values at characteristic parts of S in CHO nd E-11 cells, as determined by plotting the specific activity of nascent DNA as a function of pulse-labelling times. Renaturation kinetics of nascent DNA in CHO cells had indicated previously that a class of moderately repeated nucleotide sequences had a shorter thymine pool equilibration time than other sequences, leading to their overproduction during labelling of cells with thymidine for times shorter than the pool equilibration time. In the present experiments, the replication of these sequences occurred during those parts of S in which the thymine pool equilibration times for total nascent DNA labelling were shortest. In HeLa cells, the variation in pool equilibration time was less than in CHO and E-11 cells, and renaturation kinetics revealed no overproduction of moderately repeated nucleotide sequences at any time during S. Thus, one kind of order may characterize DNA replication in CHO cells and diploid human fibroblasts but not in HeLa cells.

• Research Organization: Univ. of California, San Francisco
• OSTI ID: 5372694
• Journal Information: Exp. Cell Res.; (United States), Journal Name: Exp. Cell Res.; (United States) Vol. 120; ISSN ECREA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CULTURES
CELL CYCLE
COMPARATIVE EVALUATIONS
CONNECTIVE TISSUE CELLS
DNA
FIBROBLASTS
HAMSTERS
HELA CELLS
HETEROCYCLIC COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MAN
NUCLEI
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PRIMATES
PYRIMIDINES
RADIOISOTOPES
REACTION KINETICS
RIBOSIDES
RODENTS
SOMATIC CELLS
THYMIDINE
THYMINE
TIME DEPENDENCE
TRITIUM
URACILS
VERTEBRATES
YEARS LIVING RADIOISOTOPES