Involvement of connexin 43 in meiotic maturation of bovine oocytes.

Details

Serval ID
serval:BIB_5B02E16C7BDA
Type
Article: article from journal or magazin.
Collection
Publications
Title
Involvement of connexin 43 in meiotic maturation of bovine oocytes.
Journal
Reproduction
Author(s)
Vozzi C., Formenton A., Chanson A., Senn A., Sahli R., Shaw P., Nicod P., Germond M., Haefliger J.A.
ISSN
1470-1626 (Print)
ISSN-L
1470-1626
Publication state
Published
Issued date
2001
Volume
122
Number
4
Pages
619-628
Language
english
Abstract
In ovarian follicles, cumulus cells provide the oocyte with small molecules that permit growth and control maturation. These nutrients reach the germinal cell through gap junction channels, which are present between the cumulus cells and the oocyte, and between the cumulus cells. In this study the involvement of intercellular communication mediated by gap junction channels on oocyte maturation of in vitro cultured bovine cumulus-oocyte complexes (COCs) was investigated. The stages of oocyte maturation were determined by Hoechst 33342 staining, which showed that 90% of COCs placed in the maturation medium for 24 h progress to the metaphase II stage. Bovine COC gap junction communication was disrupted initially using n-alkanols, which inhibit any passage through gap junctions. In the presence of 1-heptanol (3 mmol l(-1)) or octanol (3.0 mmol l(-1) and 0.3 mmol l(-1)), only 29% of the COCs reached metaphase II. Removal of the uncoupling agent was associated with restoration of oocyte maturation, indicating that treatment with n-alkanols was neither cytotoxic nor irreversible. Concentrations of connexin 43 (Cx43), the major gap junction protein expressed in the COCs, were decreased specifically using a recombinant adenovirus expressing the antisense Cx43 cDNA (Ad-asCx43). The efficacy of adenoviral infection was > 95% in cumulus cells evaluated after infection with recombinant adenoviruses expressing the green fluorescence protein. RT-PCR performed on total RNA isolated from Ad-asCx43-infected COCs showed that the rat Cx43 cDNA was transcribed. Western blot analysis revealed a three-fold decrease in Cx43 expression in COCs expressing the antisense RNA for Cx43. Injection of cumulus cells with Lucifer yellow demonstrated further that the resulting lower amount of Cx43 in infected COCs is associated with a two-fold decrease in the extent of coupling between cumulus cells. In addition, oocyte maturation was decreased by 50% in the infected COC cultures. These results indicate that Cx43-mediated communication between cumulus cells plays a crucial role in maturation of bovine oocytes.
Keywords
Adenoviridae/genetics, Animals, Blotting, Western, Cattle, Cell Culture Techniques, Connexin 43/genetics, Connexin 43/physiology, Female, Genetic Vectors/administration & dosage, Heptanol/pharmacology, Isoquinolines/diagnostic use, Meiosis, Oocytes/metabolism, Oogenesis/drug effects, RNA, Antisense/administration & dosage, Rats, Reverse Transcriptase Polymerase Chain Reaction, Transfection
Pubmed
Web of science
Open Access
Yes
Create date
25/01/2008 14:48
Last modification date
20/08/2019 15:13
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