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Sauer, K., Knoblich, J.A., Richardson, H., Lehner, C.F. (1995). Distinct modes of cyclin E/cdc2c kinase regulation and S-phase control in mitotic and endoreduplication cycles of Drosophila embryogenesis.  Genes Dev. 9(11): 1327--1339.
FlyBase ID
FBrf0082560
Publication Type
Research paper
Abstract

Drosophila cyclin E (DmcycE) is required in embryos for S phase of mitotic and endoreduplication cycles. Here, we describe regulatory differences characteristic for these two cell cycle types. While DmcycE transcript levels decline in DmcycE mutant cells programmed for mitotic proliferation, they are maintained and no longer restricted to transient pulses in DmcycE mutant cells programmed for endoreduplication. Moreover, DmcycE expression in endoreduplicating cells is down-regulated by ectopic expression of a heat-inducible cyclin E transgene. DmcycE expression in endoreduplicating tissues, therefore, is restricted by a negative feedback to the transient pulse triggering entry into S-phase. Conversely, during mitotic cycles, where S phase entry is not only dependent on cyclin E but also on progression through M phase, cyclin E and associated Dmcdc2c kinase activity are present throughout the cell cycle. Reinitiation of DNA replication during the G2 phase of the mitotic cell cycle, therefore, is prevented by cyclin E/Dmcdc2c kinase-independent regulation. Observations in cyclin A mutants implicate G2 cyclins in this regulation. Our results suggest molecular explanations for the different rules governing S phase during mitotic and endoreduplication cycles.

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    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Genes Dev.
    Title
    Genes & Development
    Publication Year
    1987-
    ISBN/ISSN
    0890-9369
    Data From Reference
    Aberrations (3)
    Alleles (9)
    Balancers (3)
    Genes (8)
    Insertions (1)
    Transgenic Constructs (3)