GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

PMID:7706401

From GONUTS
Jump to: navigation, search
Citation

Chen, X, Reynolds, ER, Ranganayakulu, G and O'Donnell, JM (1994) A maternal product of the Punch locus of Drosophila melanogaster is required for precellular blastoderm nuclear divisions. J. Cell. Sci. 107 ( Pt 12):3501-13

Abstract

The Punch locus of Drosophila melanogaster encodes the pteridine biosynthesis enzyme guanosine triphosphate cyclohydrolase. One class of Punch mutants is defective for a maternal function that results in embryonic death. We demonstrate here that the embryos exhibit nuclear division defects during the precellular blastoderm stage of development. These defects include abnormal nuclear distribution, mitotic asynchrony, and persisting chromatin bridges. Daughter nuclei that do not complete chromosome separation nevertheless initiate new interphase and mitotic cycles. As a result, interconnected mitotic figures are observed. Mitotic spindles and nuclear envelopes appear essentially normal. A mutant phenocopy was induced in wild-type embryos by treatment with the guanosine triphosphate cyclohydrolase inhibitor, 2,4-diamino-6-hydroxypyrimidine, at a very early cleavage stage. Furthermore, an inhibitor of a terminal step in pteridine biosynthesis produced an identical phenotype. Immunolocalization experiments define expression of Punch protein in nurse cells during oogenesis. The protein is packaged into granules as it is transported into the oocyte cytoplasm. As syncytial blastoderm nuclear divisions proceed, Punch protein levels decrease and disappear by cellularization. Defects in the expression of the protein in Punch maternal effect mutants correlate well with the early phenotypes. These results show that a Punch product is directly involved in early nuclear divisions and suggest a possible role in chromosome separation.

Links

PubMed

Keywords

Animals; Blastoderm/pathology; Cell Division; Cell Nucleus/pathology; Cell Nucleus/ultrastructure; Drosophila melanogaster/embryology; Female; GTP Cyclohydrolase/antagonists & inhibitors; GTP Cyclohydrolase/genetics; GTP Cyclohydrolase/metabolism; Genes, Insect/genetics; Hypoxanthines/pharmacology; Microscopy, Fluorescence; Microscopy, Immunoelectron; Microtubules/ultrastructure; Mutation; Nuclear Envelope/ultrastructure; Oogenesis/physiology; Ovum/metabolism; Phenotype; Pteridines/metabolism

Significance

Annotations

Gene product Qualifier GO ID GO term name Evidence Code with/from Aspect Notes Status


See also

References

See Help:References for how to manage references in GONUTS.