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Calcium influx, fertilisation potential and egg activation in Fucus serratus

Published online by Cambridge University Press:  26 September 2008

Stephen Roberts
Affiliation:
Marine Biological Association, Plymouth, UK
Colin Brownlee
Affiliation:
Marine Biological Association, Plymouth, UK

Summary

Fertilisation in the marine alga Fucus serratus is accompanied by increased influx of Ca2+ from the external medium. The onset of this increase, monitored with the Mn2+ fluorescence quench technique, corresponded with the depolarisation phase of the fertilisation potential. External Ca2+ was necessary for the onset of the fertilisation potential and the early activation events, including cell wall exocytosis. Removal of Ca2+ from, or addition of Sr2+ to, the external medium during the fertilisation potential reduced the magnitude of the depolarisation and prolonged its duration. While fertilisation potentials could not be elicited in the presence of 0.1 mM Ca2+, addition of Ba2+ in the presence of 0.1 mM Ca2+ allowed normal fertilisation potential and egg activation. Microinjection of ryanodine or cyclic guanosine 5'-monophosphate (cGMP) did not induce cytoplasmic Ca2+ elevation or egg activation. Inositol 1,4,5-triphosphate [Ins(l,4,5)P3] produced a transient elevation of cytoplasmic Ca2+, monitored using ratio photometry, but did not cause cell wall exocytosis except at the site of microinjection. The results demonstrate an essential role for Ca2+ influx during Fucus egg activation. The relative importance of influx and intracellular Ca2+ release in Fucus egg activation is discussed.

Type
Article
Copyright
Copyright © Cambridge University Press 1995

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References

Berridge, M.J. (1993). Inositol trisphosphate and calcium signalling. Nature 361, 315–25.CrossRefGoogle ScholarPubMed
Brawley, S.H. (1991). The fast block against polyspermy in fucoid algae is an electrical block. Dev. Biol. 144, 94106.Google Scholar
Brownlee, C. & Dale, B. (1990). Temporal and spatial correlation of fertilisation current, calcium waves and cytoplasmic contraction in eggs of Ciona intestinalis. Proc. R. Soc. Lond. B. 239, 321–8.Google Scholar
Buck, W.R., Rakow, T.L., & Shen, S.S. (1992). Synergistic release of calcium in sea urchin eggs by caffeine and ryanodine. Exp. Cell Res. 202, 5966.Google Scholar
Fasolata, C., Hoth, M., Matthews, G. & Penner, R. (1993). Ca2+ and Mn2+ influx through receptor-mediated activation of non-specific cation channels in mast cells. Proc. Natl. Acad. Sci USA 90, 3068–72.Google Scholar
Galione, A., Lee, H.C. & Busa, W.B. (1991). Ca2+-induced Ca2+ release in sea urchin egg homogenates: modulation by cyclic ADP-ribose. Science 253, 1143–6.Google Scholar
Galione, A., McDougall, A., Busa, W.B., Willmot, N., Gillot, I. & Whitaker, M. (1993). Redundant mechanisms of calcium-induced calcium release underlying calcium waves during fertilisation of sea urchin eggs. Science 261, 348–52.Google Scholar
Gilkey, J.C., Jaffe, L.F., Ridgeway, E.B. & Reynolds, G.T. (1978). A free calcium wave traverses the activating egg of medaka Oryzias latipes. J. Cell Biol. 76, 448–66.Google Scholar
Jaffe, L.F. (1983). Sources of calcium in egg activation: a review and hypothesis. Dev. Biol. 99, 265–76.Google Scholar
Jaffe, L.A., Gould-Somero, M. & Holland, L. (1979). Ionic mechanism of the fertilisation potential of the marine worm Urechis caupo (Echiura). J. Gen. Physiol. 73, 469–92.Google Scholar
Kass, E.N., Llopis, J., Duddy, S.K. & Orrenius, S. (1990). Receptor-operated calcium influx in rat hepatocytes. J. Biol. Chem. 265, 17486–92.CrossRefGoogle ScholarPubMed
Kwan, C.-Y. & Putney, J.W. (1990). Uptake and sequestration of divalent cations in resting and methacholinestimulated mouse lacrimal acinar cells. J. Biol. Chem. 265, 678–84.CrossRefGoogle ScholarPubMed
Luckhoff, A. & Clapham, D.E. (1992). Inositol 1,4,3,5-tetrakisphosphate activates and endothelial Ca2+-permeable chennel. Nature 355, 356–8.CrossRefGoogle Scholar
Marty, A. & Neher, E. (1985). Potassium channels in cultured bovine adrenal chromaffin cells. J. Physiol. (Lond.) 367, 117–41.CrossRefGoogle ScholarPubMed
Roberts, S.K., Berger, F. & Brownlee, C. (1993). The role of calcium in signal transduction following fertilisation in Fucus serratus. J. Exp. Biol. 184, 197212.Google Scholar
Roberts, S.K., Gillot, I. & Brownlee, C. (1994). Cytoplasmic calcium and fucus egg activation. Development 120, 155–63.CrossRefGoogle Scholar
Sage, O.S., Merritt, J.E., Hallam, T.R. & Rink, T.J. (1989). Receptor-mediated calcium entry in fura-2 loaded human platelets stimulated with ADP and thrombin. Biochem. J. 258, 923–6.Google Scholar
Sardet, C., Gillot, I., Ruscher, A., Payan, P. & DeRenzis, G. (1992). Ryanodine activates sea urchin eggs. Dev. Growth Differ. 34, 3742.Google Scholar
Taylor, A.R. & Brownlee, C. (1993). Calcium and potassium channels in the Fucus egg. Planta 189, 109–19.CrossRefGoogle Scholar
Whalley, T., McDougall, A., Crossley, I., Swann, K. & Whitaker, M. (1992). Internal calcium release and activation of sea urchin eggs by cGMP are independent of the phosphoinositide signalling pathway. Mol. Biol. Cell. 3, 373–83.Google Scholar