Related Experiment Videos
gamma-Glutamyl transpeptidase of spermatozoa may decrease oocyte glutathione content at fertilization in pigs
H Funahashi1, Z Machaty, R S Prather
1Department of Animal Science, University of Missouri, Columbia 65211, USA.
Molecular Reproduction and Development
|December 1, 1996
Summary
Sperm gamma-glutamyl transpeptidase (GGT) is present on boar spermatozoa and may limit male pronuclear formation. Microinjection of GGT into oocytes reduced glutathione levels and inhibited male pronuclear development, suggesting a role in fertilization.
Area of Science:
- Reproductive Biology
- Enzymology
- Cell Biology
Background:
- Gamma-glutamyl transpeptidase (GGT) is an enzyme found in various tissues, including spermatozoa.
- Its specific role in sperm function, particularly during fertilization, remains largely uncharacterized.
Purpose of the Study:
- To investigate the presence and localization of GGT in boar spermatozoa.
- To elucidate the potential role of GGT in porcine oocyte activation and male pronuclear formation.
Main Methods:
- Histochemical staining was used to detect GGT in boar spermatozoa.
- In vitro matured porcine oocytes were microinjected with GGT, GTP-gamma-S, or a control solution.
- Oocyte activation, glutathione (GSH and GSSG) content, and male pronuclear formation post-insemination were assessed.
Main Results:
- GGT was localized to the midpiece and acrosome regions of boar spermatozoa.
- Microinjection of GGT into oocytes significantly decreased total GSH and GSSG content.
- GGT injection did not affect oocyte activation but significantly inhibited male pronuclear formation after insemination.
Conclusions:
- Spermatozoal GGT is present on the sperm surface.
- Oocyte GGT content of GSH and GSSG is reduced by GGT microinjection.
- Sperm GGT may act as a limiting factor for male pronuclear formation in polyspermic porcine oocytes.