Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
Incubation of demembranated sperm chromatin in cytoplasmic extracts of unfertilized Xenopus laevis eggs resulted in nuclear envelope assembly, chromosome decondensation, and sperm pronuclear formation. In contrast, egg extracts made with EGTA-containing buffers induced the sperm chromatin to form chromosomes or irregularly shaped clumps of chromatin that were incorporated into bipolar or multipolar spindles. The 150,000 g supernatants of the EGTA extracts could not alone support these changes in incubated nuclei. However, these supernatants induced not only chromosome condensation and spindle formation, but also nuclear envelope breakdown when added to sperm pronuclei or isolated Xenopus liver or brain nuclei that were incubated in extracts made without EGTA. Similar changes were induced by partially purified preparations of maturation-promoting factor. The addition of calcium chloride to extracts containing condensed chromosomes and spindles caused dissolution of the spindles, decondensation of the chromosomes, and re-formation of interphase nuclei. These results indicate that nuclear envelope breakdown, chromosome condensation, and spindle assembly, as well as the regulation of these processes by Ca2+-sensitive cytoplasmic components, can be studied in vitro using extracts of amphibian eggs.
Bradford,
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.
1976, Pubmed
Bradford,
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding.
1976,
Pubmed Cuthbertson,
Free Ca2+ increases in exponential phases during mouse oocyte activation.
1981,
Pubmed Farzaneh,
A method for isolating uncontaminated nuclei from all stages of developing Xenopus laevis embryos.
1978,
Pubmed
,
Xenbase Gerhart,
Cell cycle dynamics of an M-phase-specific cytoplasmic factor in Xenopus laevis oocytes and eggs.
1984,
Pubmed
,
Xenbase Halleck,
Injected mitotic extracts induce condensation of interphase chromatin.
1984,
Pubmed
,
Xenbase Hepler,
Membranes in the mitotic apparatus: their structure and function.
1984,
Pubmed Kishimoto,
Generality of the action of various maturation-promoting factors.
1982,
Pubmed
,
Xenbase Lohka,
Effects of Ca2+ ions on the formation of metaphase chromosomes and sperm pronuclei in cell-free preparations from unactivated Rana pipiens eggs.
1984,
Pubmed
,
Xenbase Lohka,
Roles of cytosol and cytoplasmic particles in nuclear envelope assembly and sperm pronuclear formation in cell-free preparations from amphibian eggs.
1984,
Pubmed
,
Xenbase Lohka,
Formation in vitro of sperm pronuclei and mitotic chromosomes induced by amphibian ooplasmic components.
1983,
Pubmed
,
Xenbase Lohka,
The germinal vesicle material required for sperm pronuclear formation is located in the soluble fraction of egg cytoplasm.
1983,
Pubmed
,
Xenbase Masui,
Oocyte maturation.
1979,
Pubmed Masui,
Roles of divalent cations in maturation and activation of vertebrate oocytes.
1977,
Pubmed
,
Xenbase Masui,
Cytoplasmic control of nuclear behavior during meiotic maturation of frog oocytes.
1971,
Pubmed Meyerhof,
Ca and Mg control of cytostatic factors from Rana pipiens oocytes which cause metaphase and cleavage arrest.
1977,
Pubmed Miake-Lye,
Maturation-promoting factor induces nuclear envelope breakdown in cycloheximide-arrested embryos of Xenopus laevis.
1983,
Pubmed
,
Xenbase Nelkin,
Protein factor(s) from mitotic CHO cells induce meiotic maturation in Xenopus laevis oocytes.
1980,
Pubmed
,
Xenbase Newport,
Regulation of the cell cycle during early Xenopus development.
1984,
Pubmed
,
Xenbase Ridgway,
Free calcium increases explosively in activating medaka eggs.
1977,
Pubmed Smith,
The interaction of steroids with Rana pipiens Oocytes in the induction of maturation.
1971,
Pubmed Steinhardt,
Is calcium ionophore a universal activator for unfertilised eggs?
1974,
Pubmed
,
Xenbase Sunkara,
Mitotic factors from mammalian cells induce germinal vesicle breakdown and chromosome condensation in amphibian oocytes.
1979,
Pubmed
,
Xenbase Wasserman,
A cytoplasmic factor promoting oocyte maturation: its extraction and preliminary characterization.
1976,
Pubmed
,
Xenbase Weintraub,
[Demonstration of maturation promoting factor activity in Saccharomyces cerevisiae].
1982,
Pubmed
,
Xenbase Wu,
Partial purification and characterization of the maturation-promoting factor from eggs of Xenopus laevis.
1980,
Pubmed
,
Xenbase Ziegler,
Control of chromosome behavior in amphibian oocytes. I. The activity of maturing oocytes inducing chromosome condensation in transplanted brain nuclei.
1973,
Pubmed
