This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Nuttinck, F. Articles by Grimard, B. Search for Related Content PubMed PubMed Citation Articles by Nuttinck, F. Articles by Grimard, B.

Expression of genes involved in prostaglandin E₂ and progesterone production in bovine cumulus–oocyte complexes during in vitro maturation and fertilization

ENVA, UMR 1198, Biologie du Développement et Reproduction, 7 av du Général De Gaulle, Maisons-Alfort F-94704, France¹ INRA, UMR 1198, Biologie du Développement et Reproduction, Jouy-en-Josas F-78350, France² UNCEIA, Union Nationale des Coopératives d'Elevage et d'Insémination Artificielle, Recherche et Développement, Maisons-Alfort F-94704, France

Correspondence should be addressed to F Nuttinck; Email: fabienne.nuttinck{at}jouy.inra.fr

Prostaglandin E₂ (PGE₂) and progesterone appear to be critical mediators of cumulus expansion and the resumption of oocyte meiosis. The aim of this study was to identify the types of prostaglandin E synthase (PTGES) expressed in the bovine cumulus–oocyte complex (COC), to characterize their temporal expression during the periconceptional interval using an in vitro model of maturation (IVM) and fertilization (IVF), and to compare their expression with the level of steroidogenic gene expression. Real-time RT-PCR analysis revealed that enzymes related to the PGE₂ biosynthesis pathway were mainly expressed during IVM. Transcripts encoding PTGES1–3 were detected in bovine COCs. Only the expression of PTGES1 significantly increased during IVM whereas that of PTGES2 and PTGES3 remained unchanged. The induction of PTGES1 expression paralleled the induction of prostaglandin G/H synthase-2 (PTGS2) expression and the amounts of PGE₂ secreted by maturing COCs. Concomitantly, cholesterol side chain cleavage cytochrome P450 expression was significantly upregulated in maturing COCs and the high level of expression persisted in fertilized COCs. The expression of the StAR protein remained constant during IVM and then decreased significantly during IVF. Expression of the progesterone catabolic-related enzyme, 20-hydroxysteroid dehydrogenase significantly decreased throughout the periconceptional interval. This was associated with a rising level of progesterone released by COCs in the culture media. In conclusion, our results suggest that the periconceptional differentiation of the bovine COC includes the transient induction of PGE₂ biosynthetic activity via the PTGS2/PTGES1 pathway during the maturation period and the increasing ability to produce progesterone from the immature to the fertilized stages.