DNA-replication checkpoint control at the Drosophila midblastula transition
TLDR
This article showed that mutations in the grapes (grp) checkpoint 1 kinase homologue in Drosophila block the morphological and biochemical changes that accompany the midblastula transition, leading to a continuation of the maternal cell-cycle programme, and disrupt DNA-replication checkpoint control of cell cycle progression.Abstract:
Embryogenesis is typically initiated by a series of rapid mitotic divisions that are under maternal genetic control. The switch to zygotic control of embryogenesis at the midblastula transition is accompanied by significant increases in cell-cycle length and gene transcription, and changes in embryo morphology. Here we show that mutations in the grapes (grp) checkpoint 1 kinase homologue in Drosophila block the morphological and biochemical changes that accompany the midblastula transition, lead to a continuation of the maternal cell-cycle programme, and disrupt DNA-replication checkpoint control of cell-cycle progression. The timing of the midblastula transition is controlled by the ratio of nuclei to cytoplasm (the nucleocytoplasmic ratio), suggesting that this developmental transition is triggered by titration of a maternal factor by the increasing mass of nuclear material that accumulates during the rapid embryonic mitoses. Our observations support a model for cell-cycle control at the midblastula transition in which titration of a maternal component of the DNA-replication machinery slows DNA synthesis and induces a checkpoint-dependent delay in cell-cycle progression. This delay may allow both completion of S phase and transcription of genes that initiate the switch to zygotic control of embryogenesis.read more
Citations
More filters
Journal ArticleDOI
Cyclin A and B functions in the early Drosophila embryo.
TL;DR: Observations support the hypothesis that cyclin B regulates cytoskeletal changes while cyclin A regulates the nuclear cycles, and speculate that a balance of cyclins is necessary for proper coordination during these embryonic cycles.
Book ChapterDOI
Anterior-posterior patterning in the Drosophila embryo
TL;DR: A general review of the cascade of transcription factor interactions that defines the anterior-posterior body plan of the Drosophila embryo and a comprehensive description of the segmentation gene hierarchy.
Journal ArticleDOI
Sedimentation studies reveal a direct role of phosphorylation in Smad3:Smad4 homo- and hetero-trimerization.
TL;DR: Analytical ultracentrifuge studies on Smad3 and Smad4 protein constructs are presented to clarify the model of homo- and hetero-oligomerization and the role of phosphorylation in the activation process.
Journal ArticleDOI
Requirement for highly efficient pre-mRNA splicing during Drosophila early embryonic development
Leonardo G. Guilgur,Leonardo G. Guilgur,Pedro Prudêncio,Pedro Prudêncio,Daniel Sobral,Denisa Liszekova,André Rosa,Rui Gonçalo Martinho,Rui Gonçalo Martinho +8 more
TL;DR: These findings demonstrate for the first time the existence of a developmental pre-requisite for highly efficient splicing during Drosophila early embryonic development and suggest in highly proliferative tissues a need for coordination between cell cycle and gene architecture to ensure correct gene expression and avoid abnormally processed transcripts.
Journal ArticleDOI
Posttranslational Control of Cdc25 Degradation Terminates Drosophila’s Early Cell-Cycle Program
TL;DR: It is shown that the two Drosophila Cdc25 homologs, String and Twine, differ in their dynamics and that, contrary to current models, their downregulations are not controlled by mRNA degradation but through different posttranslational mechanisms.
References
More filters
Journal ArticleDOI
A non-radioactive in situ hybridization method for the localization of specific RNAs in Drosophila embryos reveals translational control of the segmentation gene hunchback.
Diethard Tautz,Christine Pfeifle +1 more
TL;DR: A non-radioactive in situ hybridization technique for the localization of RNA in whole mount Drosophila embryos and revealed translational control of the maternally derived hb mRNA, which was difficult to detect by conventional techniques.
Journal ArticleDOI
Cell Cycle Checkpoints: Preventing an Identity Crisis
TL;DR: Signal transduction pathways that transmit checkpoint signals in response to DNA damage, replication blocks, and spindle damage are revealed, underscoring the conservation of cell cycle regulatory machinery.
Journal ArticleDOI
A major developmental transition in early xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage
TL;DR: The Xenopus embryo undergoes 12 rapid synchronous cleavages followed by a period of slower asynchronous divisions more typical of somatic cells, termed the midblastula transition (MBT), which shows that at the MBT the blastomeres become motile and transcriptionally active for the first time.
Journal ArticleDOI
Studies of nuclear and cytoplasmic behaviour during the five mitotic cycles that precede gastrulation in Drosophila embryogenesis
V.E. Foe,B.M. Alberts +1 more
TL;DR: Using differential interference contrast optics, combined with cinematography, the morphological changes that the living, syncytial embryo undergoes from stage 10 through 14 of Drosophila embryogenesis, that is just prior to and during formation of the cellular blastoderm are studied.