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Phosphopeptide Analysis of Rodent Epididymal Spermatozoa
Published on: December 30, 2014
How is plasminogen/plasmin system contributing to regulate sperm entry into the oocyte?
Luis A Grullón1, Joaquín Gadea, Irene Mondéjar
1Department of Physiology, Faculty of Veterinary, Regional Campus of International Excellence Campus Mare Nostrum, University of Murcia, Murcia, Spain.
Reproductive Sciences (Thousand Oaks, Calif.)
|February 20, 2013
Summary
Plasminogen in the oviduct reduces sperm penetration by detaching bound sperm, not by altering sperm function or zona pellucida resistance. The fertilizing sperm likely activates plasminogen to facilitate this process.
Area of Science:
- Reproductive Biology
- Gamete Interaction
- Fertilization Mechanisms
Background:
- Plasminogen is found in the oviduct, zona pellucida (ZP), and oolemma.
- Plasminogen reduces sperm penetration during in vitro fertilization in pigs and cows.
- The mechanism of plasminogen's inhibitory effect on sperm penetration is not fully understood.
Purpose of the Study:
- To investigate how plasminogen reduces sperm penetration of the oocyte.
- To determine if plasminogen affects ZP resistance to enzymatic digestion.
- To assess plasminogen's impact on sperm functionality and sperm-ZP binding.
Main Methods:
- In vitro fertilization experiments in pigs and cows.
- Assessment of ZP resistance to enzymatic digestion.
- Evaluation of sperm viability, motility, acrosome reaction, and membrane lipid disorder.
- Analysis of sperm-ZP binding before and after sperm-ZP interaction.
Main Results:
- Plasminogen/plasmin system does not induce ZP hardening or decrease sperm functionality.
- Plasminogen significantly reduces sperm-ZP binding, detaching over 50% of bound sperm.
- The mechanism involves plasmin detaching additional spermatozoa from the ZP.
Conclusions:
- Plasminogen regulates sperm entry into the oocyte primarily by reducing sperm-zona pellucida binding.
- Fertilizing sperm may activate plasminogen to plasmin on the oocyte surface.
- Plasmin then detaches superfluous bound sperm, potentially facilitating fertilization.
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