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Structural organization of actin in the sea urchin egg cortex: microvillar elongation in the absence of actin filament bundle formation.
Begg DA
,
Rebhun LI
,
Hyatt H
.
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We have investigated the relationship between the formation of actin filament bundles and the elongation of microvilli (MV) after fertilization in sea urchin eggs. In a previous study (1979, J Cell Biol. 83:241-248) we demonstrated that increased pH induced the formation of actin filaments in isolated sea urchin egg cortices with the concomitant elongation of MV. On the basis of these results we suggested that increased cytoplasmic pH after fertilization causes a reorganization of cortical actin, which in turn provides the force for MV elongation. To test this hypothesis, we compared the morphology of microvilli in eggs activated with and without the release of fertilization acid. Activation of eggs in normal sea water with the calcium ionophore A23187 causes the release of fertilization acid and the elongation of MV containing core bundles of actin filaments. Eggs activated with A23187 in NA(+)-free water do not undergo normal fertilization acid release but develop elongated, flaccid MV. These MV contain an irregular network of actin filaments rather than the parallel bundles of filaments found in normal MV. The addition of 40 mM NaCl to these eggs results in the release of H(+) and the concomitant conversion of flaccid MV to erect MV containing typical core bundles of actin filaments. Identical results are obtained when 10 mM NH(4)Cl is substituted for NaCl. The induction of cytoplasmic alkalinization in unactivated eggs with NH(4)Cl does not cause either MV elongation or the formation of actin filament bundles . These results suggest that: (a) the elongation of MV is stimulated by a rise in intracellular free Ca(++) concentration; (b) actin filament bundle formation is triggered by an increase in cytoplasmic pH; and (c) the formation of actin filament bundles is not necessary for MV elongation but is required to provide rigid support for MV.
Begg,
The visualization of actin filament polarity in thin sections. Evidence for the uniform polarity of membrane-associated filaments.
1978, Pubmed,
Echinobase
Begg,
The visualization of actin filament polarity in thin sections. Evidence for the uniform polarity of membrane-associated filaments.
1978,
Pubmed
,
Echinobase
Begg,
pH regulates the polymerization of actin in the sea urchin egg cortex.
1979,
Pubmed
,
Echinobase
Bryan,
Separation and interaction of the major components of sea urchin actin gel.
1978,
Pubmed
,
Echinobase
Burgess,
Polarized bundles of actin filaments within microvilli of fertilized sea urchin eggs.
1977,
Pubmed
,
Echinobase
Carron,
Relation of cytoplasmic alkalinization to microvillar elongation and microfilament formation in the sea urchin egg.
1982,
Pubmed
,
Echinobase
Chambers,
The activation of sea urchin eggs by the divalent ionophores A23187 and X-537A.
1974,
Pubmed
,
Echinobase
Chambers,
Non-propagated cortical reactions induced by the divalent ionophore A23187 in eggs of the sea urchin, Lytechinus variegatus.
1979,
Pubmed
,
Echinobase
Chambers,
Development of the structural components of the brush border in absorptive cells of the chick intestine.
1979,
Pubmed
Chandler,
Membrane fusion during secretion: cortical granule exocytosis in sex urchin eggs as studied by quick-freezing and freeze-fracture.
1979,
Pubmed
,
Echinobase
Chandler,
Postfertilization growth of microvilli in the sea urchin egg: new views from eggs that have been quick-frozen, freeze-fractured, and deeply etched.
1981,
Pubmed
,
Echinobase
Eddy,
Changes in the topography of the sea urchin egg after fertilization.
1976,
Pubmed
,
Echinobase
Epel,
Activation of an Na + -dependent amino acid transport system upon fertilization of sea urchin eggs.
1972,
Pubmed
,
Echinobase
Epel,
Mechanisms of activation of sperm and egg during fertilization of sea urchin gametes.
1978,
Pubmed
,
Echinobase
Epel,
An analysis of the partial metabolic derepression of sea urchin eggs by ammonia: the existence of independent pathways.
1974,
Pubmed
,
Echinobase
Grainger,
Intracellular pH controls protein synthesis rate in the sea urchine egg and early embryo.
1979,
Pubmed
,
Echinobase
Harris,
Cortical fibers in fertilized eggs of the sea urchin Strongylocentrotus purpuratus.
1968,
Pubmed
,
Echinobase
Hartwig,
Actin-binding protein promotes the bipolar and perpendicular branching of actin filaments.
1980,
Pubmed
Jaffe,
Fast block to polyspermy in sea urchin eggs is electrically mediated.
1976,
Pubmed
,
Echinobase
Jaffe,
Membrane potential of the unfertilized sea urchin egg.
1978,
Pubmed
,
Echinobase
Johnson,
Intracellular pH and activation of sea urchin eggs after fertilisation.
1976,
Pubmed
,
Echinobase
Johnson,
Intracellular pH of sea urchin eggs measured by the dimethyloxazolidinedione (DMO) method.
1981,
Pubmed
,
Echinobase
Otto,
Redistribution of actin and fascin in sea urchin eggs after fertilization.
1980,
Pubmed
,
Echinobase
Otto,
Formation of filopodia in coelomocytes: localization of fascin, a 58,000 dalton actin cross-linking protein.
1979,
Pubmed
,
Echinobase
Paul,
Formation of fertilization acid by sea urchin eggs does not require specific cations.
1975,
Pubmed
,
Echinobase
Schroeder,
Microvilli on sea urchin eggs: a second burst of elongation.
1978,
Pubmed
,
Echinobase
Schroeder,
Surface area change at fertilization: resorption of the mosaic membrane.
1979,
Pubmed
,
Echinobase
Shen,
Intracellular pH and the sodium requirement at fertilisation.
1979,
Pubmed
,
Echinobase
Shen,
Intracellular pH controls the development of new potassium conductance after fertilization of the sea urchin egg.
1980,
Pubmed
,
Echinobase
Shen,
Direct measurement of intracellular pH during metabolic derepression of the sea urchin egg.
1978,
Pubmed
,
Echinobase
Spiegel,
Microvilli in sea urchin eggs. Differences in their formation and type.
1977,
Pubmed
,
Echinobase
Steinhardt,
Bioelectric responses of the echinoderm egg to fertilization.
1971,
Pubmed
,
Echinobase
Steinhardt,
Development of K + -conductance and membrane potentials in unfertilized sea urchin eggs after exposure to NH 4 OH.
1973,
Pubmed
,
Echinobase
Steinhardt,
Activation of sea-urchin eggs by a calcium ionophore.
1974,
Pubmed
,
Echinobase
Tilney,
Polymerization of actin. IV. Role of Ca++ and H+ in the assembly of actin and in membrane fusion in the acrosomal reaction of echinoderm sperm.
1978,
Pubmed
,
Echinobase
Tilney,
The polymerization of actin: its role in the generation of the acrosomal process of certain echinoderm sperm.
1973,
Pubmed
,
Echinobase
Tilney,
Actin, microvilli, and the fertilization cone of sea urchin eggs.
1980,
Pubmed
,
Echinobase
Wilt,
The stimulation of cytoplasmic polyadenylylation in sea urchin eggs by ammonia.
1974,
Pubmed
,
Echinobase
Zucker,
Intracellular calcium release and the mechanisms of parthenogenetic activation of the sea urchin egg.
1978,
Pubmed
,
Echinobase