On the coupling between DNA replication and mitosis
- 1 February 1989
- journal article
- Published by The Company of Biologists in Journal of Cell Science
- Vol. 1989 (Supplement) , 149-160
- https://doi.org/10.1242/jcs.1989.supplement_12.13
Abstract
The rapid, early cell divisions in Xenopus laevis embryos are driven by an inflexible oscillator that is not influenced by the state of the DNA. In contrast, mitosis in somatic cells can be prevented by blocking replication or by damaging the DNA through irradiation. We have investigated the transition from the rapid, early cell cycle to the slower, more somatic-like cell cycle that occurs after division twelve in developing Xenopus embryos, a stage called the mid-blastula transition (MBT). When aphidicolin, an inhibitor of DNA synthesis, was added to embryos just post-fertilization, the embryos continued to divide despite incomplete replication. Also, embryos incubated with aphidicolin from early times did not slow their cell cycles after division twelve as control embryos did, indicating a connection between the accumulation of DNA and the post-MBT timing of the cell cycle. However, incubation with hydroxyurea, an inhibitor of ribonucleotide reductase, resulted in an S phase arrest when the pools of dNTPs became depleted after division twelve. These experiments showed that the embryos had acquired the ability to arrest in S phase some time after the early divisions and before division thirteen. The acquisition of the ability to arrest in S phase did not depend upon new transcription. These experiments suggested that the number of nuclei present could be responsible for the extension of the cell cycle observed after the MBT. To investigate this, we added increasing concentrations of nuclei to an in vitro cell cycle system. We have shown that at high concentrations of nuclei the in vitro cycle is extended.Keywords
This publication has 29 references indexed in Scilit:
- Purification of MPF from starfish: Identification as the H1 histone kinase p34cdc2 and a possible mechanism for its periodic activationCell, 1989
- Unraveling of mitotic control mechanismsCell, 1988
- cdc2 is a component of the M phase-specific histone H1 kinase: Evidence for identity with MPFCell, 1988
- Role of nuclear material in the early cell cycle of xenopus embryosCell, 1988
- Cell cycle control by the nucleo-cytoplasmic ratio in early Drosophila developmentCell, 1986
- Spontaneous formation of nucleus-like structures around bacteriophage DNA microinjected into Xenopus eggsPublished by Elsevier ,1983
- A major developmental transition in early xenopus embryos: II. control of the onset of transcriptionCell, 1982
- A major developmental transition in early xenopus embryos: I. characterization and timing of cellular changes at the midblastula stageCell, 1982
- Control of cell division and cell differentiation by deoxynucleotides in the early embryo of Xenopus laevisCell Differentiation, 1975
- An investigation of the capacity for cleavage and differentiation in Rana pipiens eggs lacking “functional” chromosomesJournal of Experimental Zoology, 1951