Sperm Glycosidase as a Plausible Mediator of Sperm Binding to the Vitelline Envelope in Ascidians

1986 ◽  
pp. 251-260 ◽  
Author(s):  
Motonori Hoshi
Keyword(s):  
Sperm Binding ◽  
Vitelline Envelope

Immunohistochemical localisation of gp69/64 molecules in Xenopus egg envelopes in relation to their sperm binding activity

Zygote ◽  
2002 ◽  
Vol 10 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Hideo Kubo ◽  
Masaharu Kotani ◽  
Hidenori Suzuki ◽  
Norio Yoshizaki
Keyword(s):  
Monoclonal Antibody ◽  
Distribution Pattern ◽  
Fold Increase ◽  
Binding Activity ◽  
Animal Pole ◽  
Sperm Binding ◽  
Vegetal Pole ◽  
Xenopus Egg ◽  
Vitelline Envelope ◽  
Many Particles

A monoclonal antibody (6964M) was generated against the envelope component gp69/64 of Xenopus laevis eggs. On indirect immunofluorescence using this antibody, the positive reaction was seen on the surface of both vitelline envelope (VE) and coelomic envelope (CE). On immunoelectron microscopy, gp69/64 was preferentially distributed on the thick bundles forming the edge of the tunnel openings on CE, and this distribution pattern was fundamentally inherited by VE. Counting the number of immunogold particles indicated that VE has about twice as many particles as CE, with a 3-4 times higher density at the animal pole than vegetal pole. The number of sperm bound to CE was small, being approximately one-twentieth of the number of sperm bound to VE. An extremely small number of sperm (< 2 per animal hemisphere) was found to bind to VE* of activated eggs as a background. The sperm binding to CE was inhibited by pretreatment of the envelopes with 6964M or in the presence of purified gp69/64 from VE on insemination, confirming that sperm binding is mediated by gp69/64 exposed on the CE surface. In spite of at most a 2-fold increase in the amount of exposed gp69/64, the sperm binding increased about 20-fold upon CE-to-VE conversion, suggesting that the increase in the amount of exposed gp69/64 is itself insufficient to explain the increase in the number of bound sperm.

Participation of the 39-kDa glycoprotein (gp39) of the vitelline envelope of Bufo arenarum eggs in sperm–egg interaction

Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 159-171 ◽  
Author(s):  
Daniel Barrera ◽  
Ricardo J. Llanos ◽  
Dora C. Miceli
Keyword(s):  
Binding Capacity ◽  
Polyclonal Antibodies ◽  
Fertilization Rate ◽  
Sperm Head ◽  
Binding Assays ◽  
Sperm Binding ◽  
Sds Page ◽  
Bufo Arenarum ◽  
Pars Recta ◽  
Vitelline Envelope

SummaryThe acquisition of egg fertilizability in Bufo arenarum takes place during the oviductal transit and during this process the extracellular coelomic envelope (CE) of the eggs is converted into the vitelline envelope (VE). It has been stated that one of the necessary events leading to a fertilizable state is the proteolytic cleavage of CE glycoproteins in the oviductal pars recta by oviductin, a serine protease. Consequently, there is a marked increase in the relative quantity of glycoproteins with 39 (gp39) and 42 kDa (gp42) in the VE. In the present study, sperm–VE binding assays using heat-solubilized biotin-conjugated VE glycoproteins revealed that both gp39 and gp42 have sperm binding capacity. According to this result, our study was focused on gp39, a glycoprotein that we have previously reported as a homologue of mammalian ZPC. For this purpose, rabbit polyclonal antibodies against gp39 were generated at our laboratory. The specificity of the antibodies was confirmed with western blot of VE glycoproteins separated on SDS-PAGE. Immunohistochemical and immunoelectron studies showed gp39 distributed throughout the width of the VE. In addition, immunofluorescence assays probed that gp39 bound to the sperm head. Finally, as an approach to elucidate the possible involvement of gp39 in fertilization, inhibition assays showed that pretreatment of eggs with antibodies against gp39 generated a significant decrease in the fertilization rate. Therefore, our findings suggest that gp39, which is modified by oviductal action, participates as a VE glycoprotein ligand for sperm in Bufo arenarum fertilization.

scholarly journals Gamete Interactions in Xenopus laevis: Identification of Sperm Binding Glycoproteins in the Egg Vitelline Envelope

1997 ◽  
Vol 136 (5) ◽  
pp. 1099-1108 ◽  
Author(s):  
Jingdong Tian ◽  
Hui Gong ◽  
Gerald H. Thomsen ◽  
William J. Lennarz
Keyword(s):  
Xenopus Laevis ◽  
Critical Role ◽  
Initial Step ◽  
Binding Activity ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Agarose Beads ◽  
Sperm Binding ◽  
Gamete Interactions ◽  
Vitelline Envelope

A quantitative assay was developed to study the interaction of Xenopus laevis sperm and eggs. Using this assay it was found that sperm bound in approximately equal numbers to the surface of both hemispheres of the unfertilized egg, but not to the surface of the fertilized egg. To understand the molecular basis of sperm binding to the egg vitelline envelope (VE), a competition assay was used and it was found that solubilized total VE proteins inhibited sperm-egg binding in a concentration-dependent manner. Individual VE proteins were then isolated and tested for their ability to inhibit sperm binding. Of the seven proteins in the VE, two related glycoproteins, gp69 and gp64, inhibited sperm-egg binding. Polyclonal antibody was prepared that specifically recognized gp69 and gp64. This gp69/64 specific antibody bound to the VE surface and blocked sperm binding, as well as fertilization. Moreover, agarose beads coated with gp69/64 showed high sperm binding activity, while beads coated with other VE proteins bound few sperm. Treatment of unfertilized eggs with crude collagenase resulted in proteolytic modification of only the gp69/64 components of the VE, and this modification abolished sperm-egg binding. Small glycopeptides generated by Pronase digestion of gp69/64 also inhibited sperm-egg binding and this inhibition was abolished by treatment of the glycopeptides with periodate. Based on these observations, we conclude that the gp69/64 glycoproteins in the egg vitelline envelope mediate sperm-egg binding, an initial step in Xenopus fertilization, and that the oligosaccharide chains of these glycoproteins may play a critical role in this process.

Egg jelly of the newt,Cynops pyrrhogaster contains a factor essential for sperm binding to the vitelline envelope

2007 ◽  
Vol 307A (6) ◽  
pp. 301-311 ◽  
Author(s):  
Wataru Hiyoshi ◽  
Takayuki Sasaki ◽  
Eriko Takayama-Watanabe ◽  
Hiroyuki Takai ◽  
Akihiko Watanabe ◽  
...  
Keyword(s):  
Cynops Pyrrhogaster ◽  
Sperm Binding ◽  
Vitelline Envelope ◽  
Egg Jelly

Differences between antigenic determinants of pig and cat zona pellucida proteins

Reproduction ◽  
2000 ◽  
pp. 15-23 ◽  
Author(s):  
K Jewgenow ◽  
M Rohleder ◽  
I Wegner
Keyword(s):  
In Vitro Fertilization ◽  
Zona Pellucida ◽  
Antigenic Determinants ◽  
Vitro Fertilization ◽  
Contraceptive Vaccine ◽  
Sperm Binding ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Dose Dependent

Despite many efforts, the control of reproduction in feral cat populations is still a problem in urban regions around the world. Immunocontraception is a promising approach; thus the present study examined the suitability of the widely used pig zona pellucida proteins (pZP) for contraception in feral domestic cats. Purified zona pellucida proteins obtained from pig and cat ovaries were used to produce highly specific antisera in rabbits. Antibodies against pZP raised in rabbits or lions were not effective inhibitors of either in vitro sperm binding (cat spermatozoa to cat oocytes) or in vitro fertilization in cats, whereas antibodies against feline zona pellucida proteins (fZP) raised in rabbits showed a dose-dependent inhibition of in vitro fertilization. Immunoelectrophoresis, ELISA and immunohistology of ovaries confirmed these results, showing crossreactivity of anti-fZP sera to fZP and to a lesser extent to pZP, but no interaction of anti-pZP sera with fZP. It is concluded that cat and pig zonae pellucidae express a very small number of shared antigenic determinants, making the use of pZP vaccine in cats questionable. A contraceptive vaccine based on feline zona pellucida determinants will be a better choice for the control of reproduction in feral cats if immunogenity can be achieved.

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