Translator Disclaimer
1 March 2002 Connexin43 in Rat Oocytes: Developmental Modulation of Its Phosphorylation
Irit Granot, Edna Bechor, Amihai Barash, Nava Dekel
Author Affiliations +

It is well established that the 43-kDa connexin (Cx43) is predominantly expressed by ovarian somatic cells, whereas the identity of the connexins contributed by the oocyte to form gap junctions with its neighboring cells is not fully elucidated. Our study aimed to examine oocytes for the expression and regulation of Cx43 throughout oogenesis. Growing and fully grown rat oocytes that were meiotically incompetent and competent, respectively, were examined. Fully grown oocytes were analyzed either before or after reinitiation of meiosis as well as at the second meiotic metaphase. Immunofluorescent analysis of zona pellucida-free oocytes using conventional and confocal microscopy demonstrated a characteristic pattern of punctuated staining of Cx43 on the oolema. Immunogold electron microscopy localized Cx43 to the oocyte surface and the microvillar processes. Reverse transcriptase-polymerase chain reaction and Western blot analysis revealed similar amounts of Cx43 gene and protein in oocytes of different developmental stages. However, a relative increase in the phosphorylated forms of the protein was observed in fully grown oocytes that had completed their maturation. Our findings demonstrate that rat oocytes express a developmentally regulated Cx43. They further suggest that homotypic gap junctions that consist of Cx43 may be present between rat oocytes and their adjacent cumulus cells.

Irit Granot, Edna Bechor, Amihai Barash, and Nava Dekel "Connexin43 in Rat Oocytes: Developmental Modulation of Its Phosphorylation," Biology of Reproduction 66(3), 568-573, (1 March 2002).
Received: 13 June 2001; Accepted: 1 October 2001; Published: 1 March 2002

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top