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Live-cell Measurement of Odorant Receptor Activation Using a Real-time cAMP Assay
Published on: October 2, 2017
Oolemma receptors and oocyte activation.
Kenneth L White1, Barry J Pate, Benjamin R Sessions
1Animal, Dairy and Veterinary Sciences Department, and Center for Integrated BioSystems, Utah State University, Logan, UT 84322-4815, USA. ken.white@usu.edu
Systems Biology in Reproductive Medicine
|April 20, 2010
Summary
Sperm fertilization triggers calcium oscillations essential for oocyte activation. While the mouse model suggests a soluble factor, other mammals show complex pathways involving receptors and redundant processes for egg development.
Area of Science:
- Reproductive Biology
- Cellular Signaling
- Developmental Biology
Background:
- Sperm fertilization initiates intracellular calcium (Ca(2+)(i)) oscillations crucial for oocyte activation and development.
- The precise mechanisms of Ca(2+)(i) oscillation induction by sperm remain incompletely understood.
- Calcium ions play roles in cortical granule release and cell cycle regulation during oocyte activation.
Purpose of the Study:
- To explore the mechanisms by which sperm initiate intracellular calcium oscillations in mammalian oocytes.
- To compare existing models of oocyte activation, particularly the predominant mouse model, with emerging data from other mammalian systems.
- To investigate the complexity of oocyte activation pathways beyond the established phospholipase C (PLC) signaling cascade.
Main Methods:
- Review and synthesis of existing literature on sperm-induced oocyte activation.
- Analysis of hypotheses regarding sperm-oocyte interaction, including receptor-mediated pathways and soluble factors.
- Examination of evidence for alternative or redundant signaling pathways in both murine and non-murine oocytes.
Main Results:
- Two primary hypotheses for sperm-induced calcium oscillations exist: receptor-mediated activation of phospholipase C (PLC) and the delivery of a soluble factor (PLC-zeta).
- The mouse model predominantly supports the PLC-zeta hypothesis, involving phosphatidyl inositol (4,5)-bisphosphate (PIP2) hydrolysis to produce inositol trisphosphate (IP3).
- Emerging data from other mammals suggest more complex and potentially redundant oocyte activation pathways, possibly involving large, multimeric receptor complexes.
Conclusions:
- Oocyte activation by sperm is a highly intricate process involving multiple signaling pathways.
- The traditional mouse model may not fully represent the diversity of activation mechanisms across all mammals.
- Further research is needed to elucidate the complex interplay of factors and receptors involved in mammalian oocyte activation.
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