title: Drosophila wee1 has an essential role in the nuclear divisions of early embryogenesis.
abstract: In Drosophila, the maternally expressed mei-41 and grp genes are required for successful execution of the nuclear division cycles of early embryogenesis. In fission yeast, genes encoding similar kinases (rad3 and chk1, respectively) are components of a cell cycle checkpoint that delays mitosis by inhibitory phosphorylation of Cdk1. We have identified mutations in a gene encoding a Cdk1 inhibitory kinase, Drosophila wee1 (Dwee1). Like mei-41 and grp, Dwee1 is zygotically dispensable but is required maternally for completing the embryonic nuclear cycles. The arrest phenotype of Dwee1 mutants, as well as genetic interactions between Dwee1, grp, and mei-41 mutations, suggest that Dwee1 is functioning in the same regulatory pathway as these genes. These findings imply that inhibitory phosphorylation of Cdk1 by Dwee1 is required for proper regulation of the early syncytial cycles of embryogenesis.
authors.affiliation: Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Price
authors.forename: S
authors.initials: S
authors.lastname: Rabinovitch
authors.forename: P H
authors.initials: PH
authors.lastname: O'Farrell
authors.forename: S D
authors.initials: SD
authors.lastname: Campbell
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000502:physiology; D000071877:Checkpoint Kinase 1; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D029721:Drosophila Proteins; D005260:Female; D017344:Genes, Insect; D008297:Male; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D029702:Schizosaccharomyces pombe Proteins; C068689:wee1 protein, S pombe; D011505:Protein-Tyrosine Kinases; D000071877:Checkpoint Kinase 1; C000605877:grp protein, Drosophila