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Blocks to polyspermy in Chaetopterus.

Authors :
Eckberg WR
Anderson WA
Source :
The Journal of experimental zoology [J Exp Zool] 1985 Feb; Vol. 233 (2), pp. 253-60.
Publication Year :
1985

Abstract

Blocks to polyspermy may act either at the level of the egg plasma membrane to prevent gamete fusion or at the level of egg surface coats to prevent gamete attachment. The present study was undertaken to determine what type(s) of block(s) to polyspermy exist in Chaetopterus. The results showed the existence of both types. A rapid block acts at the plasma membrane level based on independence from detectable changes in the vitelline layer and is dependent on external sodium ions. A vitelline layer block had been predicted on morphological evidence and is supported here by demonstrating an increase in polyspermy following chemical disruption of the vitelline layer. However, the vitelline layer of the fertilized egg retained its ability to initiate the acrosome reaction in sperm and attach sperm which had undergone the acrosome reaction. The vitelline layer block resulted from the retraction of egg microvilli from the vitelline layer, and not from elevation of the vitelline layer per se. Thus the vitelline layer of the fertilized egg could be involved in preventing sperm penetration into the egg without being altered structurally or functionally.

Details

Language :
English
ISSN :
0022-104X
Volume :
233
Issue :
2
Database :
MEDLINE
Journal :
The Journal of experimental zoology
Publication Type :
Academic Journal
Accession number :
3919145
Full Text :
https://doi.org/10.1002/jez.1402330213