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The zinc finger transcription factor Krox-24 (NGFI-A, Egr-1) is encoded by an immediate-early serum response gene expressed in various physiological situations and tissues. To investigate its function, we have created a null allele. Mice homozygous for the mutation have a reduced body size, and both males and females are sterile. These phenotypes were(More)
Evidence from mouse mutants indicates that the Kit gene encoding KIT, a receptor present on the oocyte and theca cells, and the Mgf gene encoding KIT LIGAND, the ligand of KIT, are important regulators of oogenesis and folliculogenesis. Recently, in vitro cultures of fetal gonads, of follicles and of oocytes have identified specific targets for the KIT-KIT(More)
Paracrine regulations between the oocyte and granulosa cells are likely to be key regulators of early folliculogenesis. Evidence obtained from genetic mutants as well as in vivo experiments suggest that Kit and Kit Ligand (KL) may regulate early follicular morphogenesis and function. In this study, we used in vitro culture of intact mouse follicles to(More)
Freezing ovarian cortex is a new option to preserve the fertility of young patients undergoing cancer treatment or in women facing premature menopause. However, the best way to use this banked tissue remains unclear. The function of heterotopic and orthotopic autografts of frozen-thawed ovarian cortex of sheep was compared in the present study. Fresh and(More)
The aim of this study was to assess whether human dominant follicular fluid has the ability to modulate aromatase activity and/or granulosa cell proliferation. Dominant follicular fluid was obtained by laparoscopy before the luteinizing hormone surge in naturally cycling women while granulosa cells used in the tests were obtained from in-vitro fertilization(More)
The paper presents an update of our 1993 model of ovarian follicular development in ruminants, based on knowledge gained from the past 15 years of research. The model addresses the sequence of events from follicular formation in fetal life, through the successive waves of follicular growth and atresia, culminating with the emergence of ovulatory follicles(More)
The endocrine and ovarian effects of hypophysectomy (n = 5) and gonadotrophin-releasing hormone (GnRH) antagonist administration (Antarelix) (n = 5) were studied in gilts by comparison with control animals (n = 6). All gilts were given Regumate (20 mg/d for 18 d). The last day of Regumate was day 0. Hypophysectomy and initiation of Antarelix administration(More)
To investigate the factors contributing to the different ovulation rates observed in two strains of sheep (Booroola 5.2, Merino 1.2), in-vivo monitoring of follicular kinetics followed by histological examination of both ovaries was performed during the late luteal and follicular phases. Ewes of both strains were either ovariectomized at Day 13, or had the(More)
Prolific breeds of sheep (Romanov, Finn and Booroola Romanov crosses heterozygous for the Booroola gene (F+) were compared with breeds of lower prolificacy (Ile-de-France, Finn X Scottish Blackface, Merino X Blackface and Booroola X Romanov not carrying a copy of Booroola gene (++] by in-vivo monitoring of follicular kinetics by ink labelling during the(More)