title: Influence of antral follicle size on oocyte characteristics and embryo development in the bovine.
abstract: The developmental competence of bovine oocytes isolated from antral follicles of different sizes was assessed in three European laboratories (Belgium, UCL; Denmark, DIAS; France, INRA). Using the same protocol for in vitro production of embryos, the oocytes isolated from follicles with a diameter > or = 6 mm always gave a higher blastocyst rate than oocytes from follicles < 4 mm (UCL: 42% versus 14%, DIAS: 50% versus 35%, INRA: 39% versus 22%; P < 0.05). Blastocyst cell number was not affected by follicle size. Several parameters were investigated for these oocytes. The energy metabolism of cumulus-oocyte-complexes and of denuded oocytes was assessed by the oxygen and pyruvate uptake and by lactate release both at the beginning and the end of the maturation. No effect of follicle size could be detected but lactate release increased after maturation. The global profile of transcripts, the pattern of protein neosynthesis and the kinetics of meiosis resumption were not affected by follicle size. The developmental kinetics of derived embryos was also analysed. Whatever the follicle size, viable embryos had a shorter first and third embryonic cell cycle. Among the viable embryos, the size of the follicle interfered with the fourth cell cycle duration. A higher percentage of blastocysts issued from large follicle presented a short fourth cell cycle (9h) (35% versus 6%; P < 0.05). Beside, blastocysts derived from small follicles had a delayed cavitation and expansion. Thereby, a higher developmental competence for oocytes from follicle > or = 6 mm versus < 4 mm was demonstrated in three laboratories although no differences could be displayed directly at the oocyte level.
authors.affiliation: Institut des Sciences de la Vie, Unité des Sciences Vétérinaires, Université Catholique de Louvain (UCL), Place Croix du Sud 5 Bte 10, B-1348 Louvain-la-Neuve, Belgium. lequarre@vete.ucl.ac.be
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Lequarre
authors.forename: Céline
authors.initials: C
authors.lastname: Vigneron
authors.forename: Fabrice
authors.initials: F
authors.lastname: Ribaucour
authors.forename: Peter
authors.initials: P
authors.lastname: Holm
authors.forename: Isabelle
authors.initials: I
authors.lastname: Donnay
authors.forename: Rozenn
authors.initials: R
authors.lastname: Dalbiès-Tran
authors.forename: Henrik
authors.initials: H
authors.lastname: Callesen
authors.forename: Pascal
authors.initials: P
authors.lastname: Mermillod
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002417:Cattle / Q000196:embryology / Q000502:physiology*; D002453:Cell Cycle; D004622:Embryo, Mammalian / Q000166:cytology; D047108:Embryonic Development; D005260:Female; D020869:Gene Expression Profiling; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000033:anatomy & histology* / Q000502:physiology; D010101:Oxygen Consumption; D014176:Protein Biosynthesis; D019289:Pyruvic Acid / Q000378:metabolism; D013997:Time Factors
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid