scholarly journals Human ZP4 is not sufficient for taxon-specific sperm recognition of the zona pellucida in transgenic mice

Reproduction ◽  
2011 ◽  
Vol 141 (3) ◽  
pp. 313-319 ◽  
Author(s):  
Belinda Yauger ◽  
Nathan A Boggs ◽  
Jurrien Dean
Keyword(s):  
Transgenic Mice ◽  
Zona Pellucida ◽  
Molecular Basis ◽  
Human Sperm ◽  
Protein Isoforms ◽  
Egg Recognition ◽  
Sperm Binding ◽  
Human Fertilization ◽  
Gamete Recognition ◽  
Mouse Eggs

The molecular basis of human fertilization remains enigmatic. Mouse models are often used to study sperm–egg recognition, but the mouse zona pellucida surrounding ovulated eggs contains three proteins (ZP1, ZP2, and ZP3) whereas the human zona contains four (ZP1, ZP2, ZP3, and ZP4). Human sperm are fastidious and recognize human but not mouse eggs. Transgenic mouse lines were established to ascertain whether human ZP4 is the sole determinant of human sperm binding. Human ZP4 expressed in transgenic mice had a molecular mass similar to the range of native protein isoforms and was incorporated into the extracellular zona matrix. Transgenic females were fertile with normal litter sizes. Mouse sperm readily recognized transgenic ovulated eggs, but human sperm did not. We conclude that human ZP4 is not sufficient to support human sperm binding to the zona pellucida in transgenic mice and that other zona proteins may be needed for human gamete recognition.

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 Human sperm bind to the N-terminal domain of ZP2 in humanized zonae pellucidae in transgenic mice

2012 ◽  
Vol 197 (7) ◽  
pp. 897-905 ◽  
Author(s):  
Boris Baibakov ◽  
Nathan A. Boggs ◽  
Belinda Yauger ◽  
Galina Baibakov ◽  
Jurrien Dean
Keyword(s):  
Zona Pellucida ◽  
Human Sperm ◽  
Binding Assays ◽  
Terminal Domain ◽  
Sperm Binding ◽  
Gamete Recognition ◽  
Recombinant Peptides ◽  
Sperm Penetration ◽  
Mouse Eggs

Fertilization requires taxon-specific gamete recognition, and human sperm do not bind to zonae pellucidae (ZP1–3) surrounding mouse eggs. Using transgenesis to replace endogenous mouse proteins with human homologues, gain-of-function sperm-binding assays were established to evaluate human gamete recognition. Human sperm bound only to zonae pellucidae containing human ZP2, either alone or coexpressed with other human zona proteins. Binding to the humanized matrix was a dominant effect that resulted in human sperm penetration of the zona pellucida and accumulation in the perivitelline space, where they were unable to fuse with mouse eggs. Using recombinant peptides, the site of gamete recognition was located to a defined domain in the N terminus of ZP2. These results provide experimental evidence for the role of ZP2 in mediating sperm binding to the zona pellucida and support a model in which human sperm–egg recognition is dependent on an N-terminal domain of ZP2, which is degraded after fertilization to provide a definitive block to polyspermy.

Human ZP3 restores fertility in Zp3 null mice without affecting order-specific sperm binding

Development ◽  
1998 ◽  
Vol 125 (13) ◽  
pp. 2415-2424 ◽  
Author(s):  
T.L. Rankin ◽  
Z.B. Tong ◽  
P.E. Castle ◽  
E. Lee ◽  
R. Gore-Langton ◽  
...  
Keyword(s):  
Zona Pellucida ◽  
Molecular Basis ◽  
Human Sperm ◽  
Apparent Mass ◽  
Sperm Binding ◽  
Mammalian Fertilization ◽  
Vitro Data ◽  
In Vitro Data

The mammalian zona pellucida surrounding ovulated eggs mediates sperm binding at fertilization, provides a postfertilization block to polyspermy, and facilitates passage of pre-implantation embryos down the oviduct. Although the three zona proteins (ZP1, ZP2, ZP3) are well conserved, mammalian fertilization is relatively specific and human sperm do not bind to the mouse zona pellucida. There are considerable in vitro data that ZP3 acts as a primary sperm adhesion molecule in mice and, by analogy, a similar role has been postulated for human ZP3. Genetically altered mice lacking ZP3 (Zp3(tm/tm)) do not form a zona pellucida and are infertile. To rescue this phenotype, transgenic mice expressing human ZP3 (67% identical to mouse ZP3) were produced and bred with Zp3(tm/tm) null mice. The resultant human ZP3 rescue females had chimeric zonae pellucidae composed of mouse ZP1, mouse ZP2 and human ZP3. Human ZP3 expressed in mouse oocytes had an apparent mass (64 kDa) indistinguishable from native human ZP3 and distinct from mouse ZP3 (83 kDa). Despite the presence of human ZP3, human sperm did not bind to the chimeric zona pellucida, and notwithstanding the absence of mouse ZP3, mouse sperm bound to ovulated eggs in vitro and fertility was restored in vivo. These data have implications regarding the molecular basis of mouse and human sperm binding to their respective zonae pellucidae.

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 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.

scholarly journals Insights into the molecular basis of sperm–egg recognition in mammals

Reproduction ◽  
2004 ◽  
Vol 127 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Tanya Hoodbhoy ◽  
Jurrien Dean
Keyword(s):  
Zona Pellucida ◽  
Three Dimensional ◽  
Explanatory Models ◽  
Dimensional Structure ◽  
Side Chain ◽  
Egg Recognition ◽  
Three Dimensional Structure ◽  
Sperm Binding ◽  
Single Protein

The zona pellucida surrounding the egg and pre-implantation embryo is required for in vivo fertility and early development. Explanatory models of sperm–egg recognition need to take into account the ability of sperm to bind to ovulated eggs, but not to two-cell embryos. For the last two decades, investigators have sought to identify an individual protein or carbohydrate side chain as the ‘sperm receptor’. However, recent genetic data in mice are more consistent with the three-dimensional structure of the zona pellucida, rather than a single protein (or carbohydrate), determining sperm binding. The mouse and human zonae pellucidae contain three glycoproteins (ZP1, ZP2, ZP3) and, following fertilization, ZP2 is proteolytically cleaved. The replacement of endogenous mouse proteins with human ZP2, ZP3 or both does not alter taxon specificity of sperm binding or prevent fertility. Surprisingly, human ZP2 is not cleaved following fertilization and intact ZP2 correlates with persistent sperm binding to two-cell embryos. Taken together, these data support a model in which the cleavage status of ZP2 modulates the three-dimensional structure of the zona pellucida and determines whether sperm bind (uncleaved) or do not (cleaved).

Molecular Basis of Human Sperm-Zona pellucida Interaction

2000 ◽  
Vol 168 (1-2) ◽  
pp. 58-64 ◽  
Author(s):  
Sergio Oehninger
Keyword(s):  
Zona Pellucida ◽  
Molecular Basis ◽  
Human Sperm
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