Studies on the Acrosome. Ii. Acrosome Reaction in Starfish Spermatozoa

Dan, Jean Clark; Kitahara, Ayao; Kohri, T

doi:10.2307/1538607

Cited by 89 publications

(62 citation statements)

References 4 publications

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“…It has also been unclear what regulates the acrosome reaction that spermatozoa must undergo in order to fertilize. In the invertebrates studied, the acrosome reaction is initiated by egg-coat substances which permit a calcium influx (Dan, 1954). There is no good evidence, however, that egg-derived factors must induce the acrosome reaction in eutherian mammals.…”

Section: Introductionmentioning

confidence: 99%

Influence of complement depletion on sperm function in the female rabbit

Bedford¹,

Witkin²

1983

Reproduction

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Section: Introductionmentioning

confidence: 99%

Influence of complement depletion on sperm function in the female rabbit

Bedford¹,

Witkin²

1983

Reproduction

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“…Even ff the strikingly more generous dimensions of the Mytilus acrosome are disregarded, its general construction bears little resemblance to that of either the sea urchin (1,8) or the starfish (6,9) acrosome. With the Hydroides acrosome (2), on the other hand, it has several characteristics in common.…”

Section: Discussionmentioning

confidence: 99%

THE ACROSOME REACTION IN MYTILUS EDULIS

Niijima

Dan

1965

The Journal of Cell Biology

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The intact acrosome of the Mytilus edulis spermatozoon consists of a conical vesicle, the basal side of which is deeply invaginated so that the whole vesicle forms a sheath around a very slender axial rod, about 2.7/z long, inserted in a tube passing through the nucleus. The annular base of the acrosomal vesical is filled with a homogeneous substance; the outer wall of the vesicle is lined with a somewhat irregular layer of a particulate substance interspersed with very fine tubular elements, and its lumen is nearly filled by a strand of material which extends from the inner tip of the invagination to the apex of the acrosome. The lumen of the invagination appears empty except for the rod and a delicate sleevelike structure which surrounds it. The plasma membrane of the sperm cell lies in immediate contact with the acrosomal membrane over its whole outer surface. In its general organization, this molluscan acrosome shows a rather close homology with that of the annelid Hydroides.

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“…However, once exocytosis of the acrosomal vesicle is induced by treatment of the sperm with the egg jelly in Ca 2+ -containing seawater, the subsequent fertilization steps can take place successfully even in Ca 2+ -free seawater [7]. The first detailed analysis of the AR in marine animals has been made by Dan et al [8]. She showed the effects of egg jelly-containing seawater on starfish spermatozoa.…”

Section: Mutual Activation Of Sperm and Egg At Fertilizationmentioning

confidence: 99%

Actin, more than just a housekeeping protein at the scene of fertilization

Santella

Chun

2011

Sci. China Life Sci.

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Since the first demonstration of sperm entry into the fertilized eggs of Mediterranean sea urchin Paracentrotus lividus by Hertwig (1876), enormous progress and insights have been made on this topic. However, the precise molecular mechanisms underlying fertilization are largely unknown. The two most dramatic changes taking place in the zygote immediately after fertilization are: (i) a sharp increase of intracellular Ca 2+ that initiates at the sperm interaction site and traverses the egg cytoplasm as a wave, and (ii) the concomitant dynamic rearrangement of the actin cytoskeleton. Traditionally, this has been studied most extensively in the sea urchin eggs, but another echinoderm, starfish, whose eggs are much bigger and transparent, has facilitated experimental approaches using microinjection and fluorescent imaging methodologies. Thus in starfish, it has been shown that the sperm-induced Ca 2+ increase in the fertilized egg can be recapitulated by several Ca 2+ -evoking second messengers, namely inositol 1,4,5-trisphosphate (InsP 3 ), cyclic ADP-ribose (cADPr) and nicotinic acid adenine dinucleotide phosphate (NAADP), which may play distinct roles in the generation and propagation of the Ca 2+ waves. Interestingly, it has also been found that the dynamic rearrangement of the actin cytoskeleton in the fertilized eggs plays pivotal roles in guiding monospermic sperm entry and in the fine modulation of the intracellular Ca 2+ signaling. As it is well known that Ca 2+ regulates the structure of the actin cytoskeleton, our finding that Ca 2+ signaling can be reciprocally affected by the state of the actin cytoskeleton raises an intriguing possibility that actin and Ca 2+ signaling may form a 'positive feedback loop' that accelerates the downstream events of fertilization. Perturbation of the cortical actin networks also inhibits cortical granules exocytosis. Polymerizing actin bundles also compose the 'acrosome process,' a tubular structure protruding from the head of fertilizing sperm. Hence, actin, which is one of the most strictly conserved proteins in eukaryotes, modulates almost all major aspects of fertilization. starfish, calcium, egg maturation, fertilization, PIP2, actin cytoskeleton, cofilin Citation:Santella L, Chun J T. Actin, more than just a housekeeping protein at the scene of fertilization.

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Studies on the Acrosome. Ii. Acrosome Reaction in Starfish Spermatozoa

Abstract: Kaiui Show more

Cited by 89 publications

References 4 publications

Influence of complement depletion on sperm function in the female rabbit

Influence of complement depletion on sperm function in the female rabbit

THE ACROSOME REACTION IN MYTILUS EDULIS

Actin, more than just a housekeeping protein at the scene of fertilization

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