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Activation of Sea Urchin Eggs by Inositol Phosphates is Independent of External Calcium

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Journal Biochem J
Specialty Biochemistry
Date 1988 May 15
PMID 3421904
Citations 22
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Abstract

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; (c) in calcium-free seawater, increasing the volume of inositol trisphosphate solution injected decreased the extent of egg activation; (d) eggs in calcium-free sea water are more easily damaged by microinjection; microinjection of larger volumes increased leakage from eggs pre-loaded with fluorescent dye. We conclude that inositol phosphates do not require external calcium ions to activate sea urchin eggs. This is entirely consistent with their role as internal messengers at fertilization. The increased damage caused to eggs in calcium-free seawater injected with large volumes may allow the EGTA present in the seawater to enter the egg and chelate any calcium released by the inositol phosphates. This may explain the discrepancy between this and earlier reports.

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References
1.
Steinhardt R, Epel D . Activation of sea-urchin eggs by a calcium ionophore. Proc Natl Acad Sci U S A. 1974; 71(5):1915-9. PMC: 388353. DOI: 10.1073/pnas.71.5.1915. View

2.
Azarnia R, CHAMBERS E . The role of divalent cations in activation of the sea urchin egg. I. Effect of fertilization on divalent cation content. J Exp Zool. 1976; 198(1):65-77. DOI: 10.1002/jez.1401980109. View

3.
Steinhardt R, Zucker R, Schatten G . Intracellular calcium release at fertilization in the sea urchin egg. Dev Biol. 1977; 58(1):185-96. PMC: 4351706. DOI: 10.1016/0012-1606(77)90084-7. View

4.
Putney Jr J . Muscarinic, alpha-adrenergic and peptide receptors regulate the same calcium influx sites in the parotid gland. J Physiol. 1977; 268(1):139-49. PMC: 1283657. DOI: 10.1113/jphysiol.1977.sp011851. View

5.
Baker P, Whitaker M . Influence of ATP and calcium on the cortical reaction in sea urchin eggs. Nature. 1978; 276(5687):513-5. DOI: 10.1038/276513a0. View