Temporal sequence and spatial distribution of early events of fertilization in single sea urchin eggs
| Autor: | S J Wieland, G.T. Reynolds, Daniel P. Kiehart, A. Eisen |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Cytoplasm
Time Factors chemistry.chemical_element Calcium Exocytosis Membrane Potentials Arbacia punctulata Human fertilization biology.animal Botany Animals Sea urchin Ovum Lytechinus variegatus biology Cortical granule exocytosis Depolarization Articles Cell Biology NAD biology.organism_classification Spectrometry Fluorescence chemistry Fertilization Sea Urchins Luminescent Measurements embryonic structures Biophysics Female Oxidation-Reduction NADP |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.99.5.1647 |
| Popis: | Measurements and observations of five early events of fertilization, singly and in pairs, from single sea urchin eggs have revealed the precise temporal sequence and spatial distribution of these events. In the Arbacia punctulata egg, a wave of surface contraction occurs coincident with membrane depolarization (t = 0). These two earliest events are followed by the onset of a rapid, propagated increase in cytoplasmic-free calcium at approximately 23 s as measured by calcium-aequorin luminescence. The luminescence reaches its peak value by 40 s after the membrane depolarization. The luminescence remains uniformly elevated for some time before its decay over several minutes. The onset of an increase in the pyridine nucleotide (NAD(P)H) fluorescence follows the membrane depolarization at approximately 51 s. The fertilization membrane begins its elevation in a wave-like fashion coincidentally with the increase in NAD(P)H fluorescence. Similar results are observed in the Lytechinus variegatus egg. The results suggest that while the increase in cytoplasmic-free calcium may be important for many changes occurring in the egg, the elevated-free calcium is not directly responsible for the propagated wave of cortical granule exocytosis. |
| Databáze: | OpenAIRE |
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