Activation of Sea-Urchin Eggs by a Calcium Ionophore
نویسندگان
چکیده
منابع مشابه
Activation of sea urchin eggs by inositol phosphates is independent of external calcium.
We investigated the contribution of external calcium ions to inositol phosphate-induced exocytosis in sea urchin eggs. We show that: (a) inositol phosphates activate eggs of the sea urchin species Lytechinus pictus and Lytechinus variegatus independently of external calcium ions; (b) the magnitude and duration of the inositol phosphate induced calcium changes are independent of external calcium...
متن کاملPhosphoprotein inhibition of calcium-stimulated exocytosis in sea urchin eggs
We have investigated the role of protein phosphorylation in the control of exocytosis in sea urchin eggs by treating eggs with a thio-analogue of ATP. ATP gamma S (adenosine 5'-O-3-thiotriphosphate) is a compound which can be used as a phosphoryl donor by protein kinases, leading to irreversible protein thiophosphorylation (Gratecos, D., and E.H. Fischer. 1974. Biochem. Biophys. Res. Commun. 58...
متن کاملUltrastructural localization of calcium in unfertilized sea-urchin eggs.
The pyroantimonate technique was employed to identify the binding sites for calcium in unfertilized Arbacia punctulata and Strongylocentrotus purpuratus eggs. Since antimony is non-specific and binds with a variety of cations, the indentification of calcium was established by specific chelation with ethyleneglycol tetra-acetic acid (EGTA) and X-ray microprobe analysis. Antimony deposits were ob...
متن کاملPrevention of the cortical reaction in fertilized sea urchin eggs by injection of calcium-chelating ligands.
Eggs from the sea urchin, Lytechinus pictus, were injected with either EGTA or EDTA, and were subsequently fertilized. EGTA prevented cortical vesicle discharge and formation of the fertilization membrane. EDTA had either no effect, or sometimes retarded the elevation of the fertilization membrane, or reduced the percentage of eggs with elevated membranes. Theoretical considerations lead to est...
متن کاملAction of Colcemid in Sea Urchin Eggs
The effects of Colcemid, the deacetyl-N-methyl derivative of colchicine, on the eggs of Arbacia punctulata were investigated. Colcemid in concentrations of 2.7 x 10(-5)M or greater blocks syngamy (the fusion of the pronuclei) in these eggs. Although a tenfold decrease in concentration of Colcemid usually permits the pronuclei to fuse, the subsequent division is blocked. In the sea urchin egg, t...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1974
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.71.5.1915