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This Article Full Text Full Text (PDF) All Versions of this Article: 68/5/1934    most recent biolreprod.102.011452v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend 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 Comizzoli, P. Articles by Renard, J.P. Search for Related Content PubMed PubMed Citation Articles by Comizzoli, P. Articles by Renard, J.P. Agricola Articles by Comizzoli, P. Articles by Renard, J.P.

Up-Regulation of Glucose Metabolism During Male Pronucleus Formation Determines the Early Onset of the S Phase in Bovine Zygotes¹

Institut National de la Recherche Agronomique,³ Biologie du Développement et Biotechnologie, 78352 Jouy-en-Josas, France Clinic of Sterility, Department of Obstetrics and Gynecology,⁴ University Hospital of Geneva, 1211 Geneva 14, Switzerland and Department of Obstetrics and Gynecology,⁵ Yale University School of Medicine, New Haven, Connecticut 06510

After in vitro fertilization with spermatozoa from bulls with high in vitro fertility, a beneficial paternal effect is manifested during the G1 phase of the first cell cycle. This benefit determines an earlier onset of the first S phase, and then a successful morula-blastocyst transition 7 days later. We hypothesized that the origin of the paternal effect could be a shift of the metabolism of the fertilized oocyte, because in mice, sperm decondensation is responsible for a dramatic increase in glucose metabolism. In this study we investigated the interaction between both pronuclei and compared glycolysis and pentose phosphate pathway (PPP) activities in bovine oocytes fertilized with spermatozoa from bulls of high or low fertility. Here we demonstrate that male pronucleus formation is necessary for the onset of the S phase in the female pronucleus, and that the component promoting an early S phase in both pronuclei is metabolic and linked to an up-regulation of the PPP during the male pronucleus formation. This long-lasting paternal effect is more evidence of the important role of epigenetic control during early embryo development.

¹ Supported by grant CT 98-4339 from the European Union (directorate general VI, program FAIR, "embryonic origin of health and welfare in cattle and sheep"). Part of this study was also supported by grant 32-55693.98 from the Fonds National Suisse de la Recherche Scientifique. P.C. was supported by grant 97298 035 from the Conseil Régional de la Région Centre.

² Correspondence: J.P. Renard, INRA, Biologie du Développement et Biotechnologie, 78352 Jouy-en-Josas, France. FAX: 33 1 34 65 26 77; renard{at}jouy.inra.fr