title: Timing the Drosophila Mid-Blastula Transition: A Cell Cycle-Centered View.
abstract: At the mid-blastula transition (MBT), externally developing embryos refocus from increasing cell number to elaboration of the body plan. Studies in Drosophila reveal a sequence of changes in regulators of Cyclin:Cdk1 that increasingly restricts the activity of this cell cycle kinase to slow cell cycles during early embryogenesis. By reviewing these events, we provide an outline of the mechanisms slowing the cell cycle at and around the time of MBT. The perspectives developed should provide a guiding paradigm for the study of other MBT changes as the embryo transits from maternal control to a regulatory program centered on the expression of zygotic genes.
authors.affiliation: Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA 94158, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Yuan
authors.affiliation: Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA 94158, USA.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Seller
authors.affiliation: Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA 94158, USA.
authors.forename: Antony W
authors.initials: AW
authors.lastname: Shermoen
authors.affiliation: Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA 94158, USA. Electronic address: ofarrell@cgl.ucsf.edu.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: O'Farrell
mesh_terms: D000818:Animals; D036703:Blastula / Q000254:growth & development; D016203:CDC2 Protein Kinase / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics; D016213:Cyclins / Q000235:genetics*; D004330:Drosophila / Q000235:genetics / Q000254:growth & development; D029721:Drosophila Proteins; D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*
chemical_list: D016213:Cyclins; D029721:Drosophila Proteins; D016203:CDC2 Protein Kinase; C000601753:Cdk1 protein, Drosophila
keywords: Cdc25; DNA replication; S phase checkpoint; cyclin:Cdk1; mid-blastula transition (MBT)