Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 01/1994 |
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<mark>Journal</mark> | Development |
Issue number | 1 |
Volume | 120 |
Number of pages | 9 |
Pages (from-to) | 155-163 |
Publication Status | Published |
<mark>Original language</mark> | English |
Eggs of the marine brown alga, Fucus serratus, exhibit small transient elevations of cytosolic Ca2+ of variable magnitude, corresponding to the onset of the fertilization potential. Microinjection of Ca2+ buffers (BAPTA (1-2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)) at concentrations sufficient to block any global fertilization-associated Ca-cyt(2+) elevation did not inhibit egg activation (monitored as exocytosis of cell wall) or subsequent development. However, egg activation could be inhibited with higher buffer concentrations. Br(2)BAPTA (K-d = 1.6 mu M) was a more effective inhibitor of egg activation than BAPTA (K-d = 0.17 mu M). Localized microinjection of Ca2+ produced only localized cell wall exocytosis at the injection site. Eggs injected with Br(2)BAPTA at intracellular concentrations, which blocked egg activation, exhibited prolonged fertilization potentials. Ca-45(2+) influx across the plasma membrane increased during fertilization. Our results show that a large transient global elevation of Ca-cyt(2+) is not necessary for Fucus egg activation but rather a localized elevation to micromolar levels results, at least in part, from increased Ca2+ influx across the plasma membrane. This is needed for early fertilization events, including the generation of the fertilization potential and cell wall secretion.