GSBS Student Publications

Title

DNA-replication checkpoint control at the Drosophila midblastula transition

Publication Date

1997-07-03

UMMS Affiliation

Graduate School of Biomedical Sciences; Program in Molecular Medicine

Document Type

Article

Disciplines

Life Sciences | Medicine and Health Sciences

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.

DOI of Published Version

10.1038/40439

Source

Nature. 1997 Jul 3;388(6637):93-7. Link to article on publisher's site

Journal/Book/Conference Title

Nature

Related Resources

Link to Article in PubMed

PubMed ID

9214509

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