Egg yolk enhances the receptiveness of zona pellucida to sperm binding

1994 ◽  
Vol 11 (7) ◽  
pp. 332-334
Author(s):  
Deborah E. Johnson ◽  
Wendy J. Holmgren ◽  
Rajasingam S. Jeyendran
Keyword(s):  
Zona Pellucida ◽  
Egg Yolk ◽  
Sperm Binding

80 TREATING BOAR SPERM WITH CHOLESTEROL IMPROVES CRYOSURVIVAL

2011 ◽  
Vol 23 (1) ◽  
pp. 145
Author(s):  
E. A. Moraes ◽  
C. A. A. Torres ◽  
J. K. Graham ◽  
P. L. Romualdo ◽  
P. S. Lopes
Keyword(s):  
Liquid Nitrogen ◽  
Zona Pellucida ◽  
Lipid Composition ◽  
Plasma Membranes ◽  
Egg Yolk ◽  
Glass Container ◽  
Epifluorescence Microscopy ◽  
Freezing And Thawing ◽  
Sperm Binding ◽  
Boar Sperm

Altering the lipid composition of plasma membranes not only affects the ability of sperm to capacitate and acrosome react, but also affects the way sperm respond to cryopreservation. When cyclodextrins are preloaded with cholesterol to form cholesterol-loaded-cyclodextrin (CLC) and then incubated with bull sperm before cryopreservation, higher percentages of motile and viable cells are recovered after freezing and thawing compared with control sperm. The amount of cholesterol in a membrane is important for maintaining its integrity during cryopreservation, and CLC alters the lipid composition of sperm, affecting their cryosurvival. This study evaluated the effect of adding cholesterol to boar sperm on cryosurvival rates and the ability of cryopreserved sperm to bind to the zona pellucida. Methyl-β-cyclodextrin was loaded with cholesterol as follows: 0.45 mL of cholesterol (200 mg mL–1 in chloroform) was added to 1 g of methyl-β-cyclodextrin dissolved in 2 mL of methanol, and the solution was stirred until clear. The mixture was poured into a glass dish and the solvents removed using a stream of nitrogen gas. The resulting crystals were allowed to dry for an additional 24 h, at which time they were removed from the dish and stored in a glass container at 22°C. A working solution of the cholesterol-loaded cyclodextrin was prepared by adding 50 mg of CLC to 1 mL TALP at 37°C and mixing the solution briefly using a vortex mixer. Ejaculates from each of 8 boars were collected, diluted 1:1 in BTS® (Minitub, Brazil), and maintained for 2 h at room temperature. The ejaculates were then cooled to 15°C over 60 min. The ejaculates were then centrifuged at 400 × g for 10 min (at 15°C), the supernatant was discarded, and the sperm were suspended to 120 × 106 cells in cooled diluent (80 mL of lactose solution 11%, 20 mL of egg yolk). The sperm were divided into 2 treatments (T): T1 = control and T2 = 1.5 mg of CLC mL–1. The samples incubated for 15 min at 15°C, after which they were cooled to 5°C over 90 min and diluted 1:1 (v:v) with Freeze diluent (2.5 mL of lactose solution 11%, 6 mL of glycerol, and 1.5 mL of Orvus-es-Paste). The sperm were then packaged into 0.5-mL French straws and frozen in static liquid nitrogen vapor (4.5 cm above the liquid nitrogen) for 20 min before being plunged into liquid nitrogen for storage. Straws were thawed and the efficiency of the sperm to bind to both the chicken egg perivitelline membrane (EPM) and porcine zona pellucida (PZP) were determined using epifluorescence microscopy. The post-thaw motility and binding efficiency of sperm to salt-stored EPM and PZP were analysed by analysis of variance. Boar sperm treated with CLC maintained higher post-thaw motility than control sperm (47 and 34%, respectively; P < 0.05) and had higher numbers of sperm binding to the PZP and EPM (101 sperm/EPM and 166 sperm/PZP) than control samples (77 sperm/EPM and 65 sperm/PZP; P < 0.05). In addition, sperm were easier to visualise on the EPM than the porcine zona pellucida. Adding CLC to boar sperm before cryopreservation increased the number of sperm surviving cryopreservation. Fapemig, CNPq, and CAPES from Brazil.

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.

Sperm binding to the human zona pellucida and calcium influx in response to GnRH and progesterone

Andrologia ◽  
2002 ◽  
Vol 34 (5) ◽  
pp. 301-307 ◽  
Author(s):  
P. Morales ◽  
E. Pizarro ◽  
M. Kong ◽  
C. Pasten
Keyword(s):  
Zona Pellucida ◽  
Calcium Influx ◽  
Sperm Binding

Characterization of Human Sperm Binding to Homologous Recombinant Zona Pellucida Proteins

2011 ◽  
Vol 18 (9) ◽  
pp. 876-885 ◽  
Author(s):  
Mayel Chirinos ◽  
Cecilia Cariño ◽  
María Elena González-González ◽  
Ernesto Arreola ◽  
Rodrigo Reveles ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Human Sperm ◽  
Sperm Binding

scholarly journals A single domain of the ZP2 zona pellucida protein mediates gamete recognition in mice and humans

2014 ◽  
Vol 205 (6) ◽  
pp. 801-809 ◽  
Author(s):  
Matteo A. Avella ◽  
Boris Baibakov ◽  
Jurrien Dean
Keyword(s):  
Transgenic Mice ◽  
Zona Pellucida ◽  
Human Sperm ◽  
Recombinant Peptide ◽  
Genetic Ablation ◽  
Sperm Binding ◽  
Gamete Recognition ◽  
Mammalian Fertilization ◽  
Human And Mouse

The extracellular zona pellucida surrounds ovulated eggs and mediates gamete recognition that is essential for mammalian fertilization. Zonae matrices contain three (mouse) or four (human) glycoproteins (ZP1–4), but which protein binds sperm remains controversial. A defining characteristic of an essential zona ligand is sterility after genetic ablation. We have established transgenic mice expressing human ZP4 that form zonae pellucidae in the absence of mouse or human ZP2. Neither mouse nor human sperm bound to these ovulated eggs, and these female mice were sterile after in vivo insemination or natural mating. The same phenotype was observed with truncated ZP2 that lacks a restricted domain within ZP251–149. Chimeric human/mouse ZP2 isoforms expressed in transgenic mice and recombinant peptide bead assays confirmed that this region accounts for the taxon specificity observed in human–mouse gamete recognition. These observations in transgenic mice document that the ZP251–149 sperm-binding domain is necessary for human and mouse gamete recognition and penetration through the zona pellucida.

scholarly journals The molecular basis of mouse sperm–zona pellucida binding: a still unresolved issue in developmental biology

Reproduction ◽  
2011 ◽  
Vol 142 (3) ◽  
pp. 377-381 ◽  
Author(s):  
Gary F Clark
Keyword(s):  
Zona Pellucida ◽  
Molecular Basis ◽  
Three Dimensional ◽  
Inhibitory Effect ◽  
Specific Model ◽  
Cell Stage ◽  
Sperm Binding ◽  
Potent Inhibitory Effect ◽  
Alternate Model ◽  
Sperm Plasma Membrane

During murine fertilization, sperm bind to the specialized extracellular matrix of the egg, known as the zona pellucida (ZP). This matrix is composed of three major glycoproteins designated ZP1, ZP2, and ZP3. Three models for sperm–ZP binding are now under consideration. The domain-specific model posits that adhesion relies primarily on interactions between N-glycans located within the C-terminal domain of ZP3 and a lectin-like egg-binding protein in the sperm plasma membrane. However, this model does not explain recent results obtained in studies with ZP2mut mice. In the supramolecular structure model, sperm bind to a three-dimensional zona matrix that depends on the cleavage status of ZP2. This paradigm does not explain the potent inhibitory effect of specific carbohydrate sequences or a C-terminal glycopeptide (gp55) derived from ZP3. Recently, O-glycans linked at Thr155 and Thr162 of ZP3 were implicated as potential ligands that mediate initial sperm–ZP binding. This novel model will be reviewed. A major challenge is to develop an alternate model for sperm–ZP binding that fits as much of the data as possible. Such a model is presented in this review. This paradigm could explain how the inability to cleave ZP2mut in ZP2mut mice could result in continued sperm binding to two-cell stage embryos without the formation of a supramolecular binding complex. These novel insights should guide future experiments that will eventually determine the molecular basis underlying gamete binding in the mouse and other eutherian mammals.

Functional interactions between sulphated polysaccharides and proacrosin: implications in sperm binding and digestion of zona pellucida

Zygote ◽  
1999 ◽  
Vol 7 (2) ◽  
pp. 105-111 ◽  
Author(s):  
R. D. Moreno ◽  
M. Hoshi ◽  
C. Barros
Keyword(s):  
Zona Pellucida ◽  
Active Site ◽  
Acrosome Reaction ◽  
Penetration Rate ◽  
Limited Proteolysis ◽  
Sulphated Polysaccharides ◽  
Functional Interactions ◽  
Sperm Binding ◽  
Sperm Penetration ◽  
Sperm Acrosome Reaction

Acrosin is a serine protease located within mammalian acrosome as inactive proacrosin. Sulphated polymers bind to proacrosin and acrosin, to a domain different from the active site. Upon binding, these polymers induce proacrosin activation and some of them, such as fucoidan, inhibit sperm binding to the zona pellucida. In this work we have studied the interaction of solubilised zona pellucida glycoproteins (ZPGs), heparin and ARIS (Acrosome Reaction Inducing Substance of Starfish) with boar and human acrosin. We have found that ARIS, solubilised ZPGs and fucoidan, but not heparin, inhibit the binding of the monoclonal antibody against human acrosin C5F10 to boar or human proacrosin. These results suggest that fucoidan, solubilised ZPGs and ARIS bind to a related domain on the proacrosin surface. Moreover, ARIS was able to induce human proacrosin activation. On the other hand, neither ARIS nor heparin from porcine intestinal mucosa or bovine lung induced hamster sperm acrosome reaction or sperm motility. Recent data showed that acrosin is involved in dispersal of the acrosomal matrix after acrosome reaction. Thus, the control of the ZPG glycan chains over proacrosin activation may regulate both sperm penetration rate and limited proteolysis of zona pellucida proteins.

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