scholarly journals Sperm Proteasomes Degrade Sperm Receptor on the Egg Zona Pellucida during Mammalian Fertilization

PLoS ONE ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. e17256 ◽  
Author(s):  
Shawn W. Zimmerman ◽  
Gaurishankar Manandhar ◽  
Young-Joo Yi ◽  
Satish K. Gupta ◽  
Miriam Sutovsky ◽  
...  
Development ◽  
1990 ◽  
Vol 108 (1) ◽  
pp. 1-17 ◽  
Author(s):  
P.M. Wassarman

Complementary molecules on the surface of eggs and sperm are responsible for species-specific interactions between gametes during fertilization in both plants and animals. In this essay, several aspects of current research on the mouse egg receptor for sperm, a zona pellucida glycoprotein called ZP3, are addressed. These include the structure, synthesis, and functions of the sperm receptor during oogenesis and fertilization in mice. Several conclusions are drawn from available information. These include (I) ZP3 is a member of a unique class of glycoproteins found exclusively in the extracellular coat (zona pellucida) of mammalian eggs. (II) ZP3 gene expression is an example of oocyte-specific and, therefore, sex-specific gene expression during mammalian development. (III) ZP3 is a structural glycoprotein involved in assembly of the egg extracellular coat during mammalian oogenesis. (IV) ZP3 is a sperm receptor involved in carbohydrate-mediated gamete recognition and adhesion during mammalian fertilization. (V) ZP3 is an inducer of sperm exocytosis (acrosome reaction) during mammalian fertilization. (VI) ZP3 participates in the secondary block to polyspermy following fertilization in mammals. (VII) The extracellular coat of other mammalian eggs contains a glycoprotein that is functionally analogous to mouse ZP3. The unique nature, highly restricted expression, and multiple roles of ZP3 during mammalian development make this glycoprotein a particularly attractive subject for investigation at both the cellular and molecular levels.


2021 ◽  
Author(s):  
Sarah Herberg ◽  
Yoshitaka Fujihara ◽  
Andreas Blaha ◽  
Karin Panser ◽  
Kiyonari Kobayashi ◽  
...  

Fertilization is the fundamental process that initiates the development of a new individual in all sexually reproducing species. Despite its importance, our understanding of the molecular players that govern mammalian sperm-egg interaction is incomplete, partly because many of the essential factors found in non-mammalian species do not have obvious mammalian homologs. We have recently identified the Ly6/uPAR protein Bouncer as a new, essential fertilization factor in zebrafish (Herberg et al., 2018). Here, we show that Bouncer's homolog in mammals, SPACA4, is also required for efficient fertilization in mice. In contrast to fish, where Bouncer is expressed specifically in the egg, SPACA4 is expressed exclusively in the testis. Male knockout mice are severely sub-fertile, and sperm lacking SPACA4 fail to fertilize wild-type eggs in vitro. Interestingly, removal of the zona pellucida rescues the fertilization defect of Spaca4-deficient sperm in vitro, indicating that SPACA4 is not required for the interaction of sperm and the oolemma but rather of sperm and zona pellucida. Our work identifies SPACA4 as an important sperm protein necessary for zona pellucida penetration during mammalian fertilization.


2014 ◽  
Vol 205 (6) ◽  
pp. 801-809 ◽  
Author(s):  
Matteo A. Avella ◽  
Boris Baibakov ◽  
Jurrien Dean

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.


1996 ◽  
Vol 134 (3) ◽  
pp. 637-645 ◽  
Author(s):  
C Arnoult ◽  
Y Zeng ◽  
H M Florman

The sperm acrosome reaction is a Ca(2+)-dependent secretory event required for fertilization. Adhesion to the egg's zona pellucida promotes Ca2+ influx through voltage-sensitive channels, thereby initiating secretion. We used potentiometric fluorescent probes to determine the role of sperm membrane potential in regulating Ca2+ entry. ZP3, the glycoprotein agonist of the zona pellucida, depolarizes sperm membranes by activating a pertussis toxin-insensitive mechanism with the characteristics of a poorly selective cation channel. ZP3 also activates a pertussis toxin-sensitive pathway that produces a transient rise in internal pH. The concerted effects of depolarization and alkalinization open voltage-sensitive Ca2+ channels. These observations suggest that mammalian sperm utilize membrane potential-dependent signal transduction mechanisms and that a depolarization pathway is an upstream transducing element coupling adhesion to secretion during fertilization.


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