| Autor: |
Wright, Philip J., Green, Jonathan R., Callow, James A. |
| Předmět: |
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| Zdroj: |
Journal of Phycology; Aug95, Vol. 31 Issue 4, p584-591, 8p |
| Abstrakt: |
To explore the molecular basis of egg-sperm recognition in the brown alga, Fucus serratus L., we developed an in vitro binding assay involving egg plasma membrane vesicles (PMVs) and proteins contained in a KCl extract of sperm. Binding between the two components was measured using biotinylated PMVs followed by the addition of streptavidin conjugated to alkaline phosphatase and the appropriate substrate. Biotinylation did not affect the ability of egg PMVs to inhibit fertilization in a species-preferential manner. Biding of labeled egg PMVs to the sperm KCl extract was not species-specific. Protease treatment of the KCl extract abolished binding, whereas periodate had no effect, suggesting that sperm protein rather than carbohydrate was involved. Preincubation of the sperm extract with sulfated polysaccharides (e.g. fucoidan and ascophyllan) inhibited binding of egg plasma membranes. Sulfation seems to be important for this effect since desulfated fucoidan was far less effective at blacking binding. Polysaccharides which inhibited binding also inhibited fertilization. Overall, the results indicate that at least some aspects of binding between Fucus sperm and eggs are mediated by a protein(s) derived from sperm which recognizes sulfated glycoconjugates on the egg plasma membrane. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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