Results 131 to 140 of about 13,944 (183)

The acrosome reaction in boar spermatozoa*

Human Reproduction, 1988
In order to gain more insight into the molecular alterations of the acrosome, boar spermatozoa were incubated in a calcium-containing medium in the presence of the ionophore A23187. The time-course of the acrosome reaction was assessed by phase-contrast microscopy.
E, Töpfer-Petersen, A E, Friess, W B, Schill   +2 more
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The acrosome reaction in human spermatozoa

Biology of the Cell, 2000
During gamete interaction, sperm acrosome reaction (AR) induced by oocyte investment is a prerequisite event for the spermatozoa to pass through the zona pellucida (ZP), fuse with and penetrate the oocyte. Progesterone (P4), secreted by cumulus cells, is an important cofactor for the occurrence of this exocytosis event.
C, Patrat, C, Serres, P, Jouannet
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The ionophore‐induced acrosome reaction differs structurally from the spontaneous acrosome reaction

Journal of Experimental Zoology, 1992
AbstractThe ultrastructure of the spontaneous acrosome reaction in ram spermatozoa has been compared with that induced by the ionophore, A23187. The spontaneous event was dependent on incubation for 4 h, on the temperature, and on dilution. Apart from the more rapid occurrence of the ionophore‐induced event, the mean diameter and distribution of ...
P F, Watson, J M, Plummer, P S, Jones
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The Acrosome Reaction

1956
Publisher Summary The reaction of the acrosome holds a general significance in connection with the fertilization process. This chapter discusses the structural aspects of the acrosome reaction including groups of Echinoidea, Asteroidea, Holothuroidea, Ophiuroidea, and Mollusca—Pelecypoda, Gastropoda, and Annelida.
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[Acrosome reaction and fertilization].

Contraception, fertilite, sexualite (1992), 1994
The acrosome reaction that occurs after sperm capacitation, is an exocytotic event induced by a Ca++ influx. It plays an essential role during fertilization, by making spermatozoa able of penetrating the zona and capable of fusing with the egg plasma membrane. Zona pellucida is the natural inducer of the acrosome reaction. Binding of the sperm receptor
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The Acrosome Reaction

1977
No morphological change has been observed in mouse (Bryan, 1974) or rabbit (Bedford, 1969) spermatozoa lying free in the ampulla of the oviduct. However, as the spermatozoa pass through the cumulus oophorus the outer acrosomal membrane may invaginate to form membrane-bound vesicles within the acrosome followed by loss of the plasma membrane (Jones ...
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The Acrosome Reaction: A Historical Perspective

2016
Acrosome reaction is often referred to as acrosomal exocytosis, but it differs significantly from normal exocytosis. While the vesicle membrane initially holding excreting molecules remains on the cell surface during exocytosis, the outer acrosomal membrane and plasma membrane are lost by forming vesicles during acrosome reaction.
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Mammalian Sperm Acrosomal Enzymes and the Acrosome Reaction

1991
The sperm acrosome is an intracellular membrane-limited organelle that surrounds the anterior portion of the nucleus. It consists of an inner acrosomal membrane that is closely associated with the nucleus and is continuous with the outer acrosomal membrane. The acrosomal matrix proper is located between the two membranes.
L. J. D. Zaneveld, C. J. De Jonge
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Capacitation and the acrosome reaction in marsupial spermatozoa

Reproduction, Fertility and Development, 1996
Although yet to be established definitively, it appears that marsupial spermatozoa require a process of capacitation and that the mechanisms involved may be quite different between the Australian and American species. For Australian species, failure to induce this functional event in culture has meant that in vitro fertilization (IVF) is yet to be ...
K E, Mate, J C, Rodger
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Induced acrosome reactions as fertility predictor

Journal of Assisted Reproduction and Genetics, 1994
This study was conducted to determine the fertility predictive value of acrosome reaction rates and indices (induced minus control) of human spermatozoa. By comparison these outcomes with in vitro fertilization success. The effect of oocyte-cumulus complex exposure on the induction of the acrosome reaction was also analyzed.
K, Coetzee, J, Olmedo, C J, Lombard
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