Related Experiment Videos
Coexpression of gap junction proteins in the cumulus-oocyte complex
G Valdimarsson1, P A De Sousa, G M Kidder
1Department of Zoology, University of Western Ontario, London, Canada.
Molecular Reproduction and Development
|September 1, 1993
Summary
Connexin 32 (Cx32) and connexin 43 (Cx43) are present in mouse oocytes and cumulus cells, forming gap junctions between cumulus cells. Cx32 mRNA levels decrease after hCG stimulation, suggesting a role in oocyte-cumulus communication.
Area of Science:
- Cell Biology
- Reproductive Biology
- Molecular Biology
Background:
- Connexins form gap junctions, crucial for intercellular communication.
- Previous studies indicated connexins 32 and 43 in mouse zygotes.
- These connexins may mediate oocyte-cumulus granulosa cell coupling during oogenesis.
Purpose of the Study:
- To investigate the presence and role of connexins 32 and 43 in the cumulus-oocyte complex (COC).
- To analyze connexin expression and localization in oocytes and cumulus cells.
Main Methods:
- Reverse transcription-polymerase chain reaction (RT-PCR) to detect connexin transcripts.
- Immunocytochemistry with confocal microscopy to visualize connexin proteins.
- Analysis of COC from PMSG-primed and hCG-stimulated mice.
Main Results:
- Both connexin32 (Cx32) and connexin43 (Cx43) transcripts were found in oocytes and cumulus cells.
- Cx32 mRNA significantly decreased in oocytes post-hCG stimulation.
- Cx32 and Cx43 were localized to gap junction-like structures between cumulus cells, but not definitively in oocyte gap junctions.
Conclusions:
- Connexins 32 and 43 are expressed in the mouse COC, with Cx43 predominantly in cumulus cell gap junctions.
- Cx32 expression in oocytes is dynamically regulated by hCG, suggesting a role in oocyte-cumulus communication.
- Oocyte Cx32 is not incorporated into gap junctions during early post-fertilization development.