During each reproductive cycle, a preovulatory surge of gonadotropins induces meiotic maturation of the oocyte in the preovulatory follicle followed by ovulation. Although gonadotropins stimulate cAMP production in somatic cells of the follicle, a decrease in intra-oocyte cAMP levels is required for resumption of meiosis in oocytes. Based on the observed compartmentalization of the cAMP-degradi...

Background: In vitro maturation (IVM) of oocytes reduces the costs and averts the side-effects of gonadotropin stimulation for in vitro fertilization (IVF). Reliable IVM is an intellectual, scientific and clinical challenge with a number of potential applications. Objective: The effect of hCG was evaluated on the timing and regulation of in vitro ovulation for the Syrian mice oocytes in the pre...

The primary objective of this study was to compare expression of maternal transcripts in bovine oocyte populations with differential developmental competence: oocytes from prepubertal and pubertal animals; and oocytes from small (3-4 mm) and large (6-10 mm) follicles from pubertal animals. All transcripts were examined in oocytes prior to and after in vitro maturation (IVM). Genes were selected...

Background: In vitro culture of ovarian follicles may preserve fertility in women with premature ovarian failure due to cancer .It seems that creation a condition that could maintain cellular communications and supports growth of follicles to produce mature oocytes appear to be essential. Nitric oxide (NO) has been recently shown to act with a dual action in mouse oocyte meiotic maturation depe...

Monitoring of individual follicles during the menstrual cycle demonstrates in a non-invasive way the changes in their number and position during the early and the late follicular phase and the luteal phase. The differences in relations between the follicles near the dominant follicle can be demonstrated with the same technique using 3D reconstruction of the ovary. Recognition of the follicle gr...

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Prostaglandins are local transient hormones that mediate a wide variety of biological events, including reproduction. The study of prostaglandin biology in a genetically tractable invertebrate model organism has been limited by the lack of clearly identified prostaglandin-mediated biological processes and prostaglandin metabolic genes, particularly analogs of cyclooxygenase (COX), the rate-limi...

Most organisms modulate their reproductive activity responding to day length by the nocturnal release of melatonin by the pineal gland. This hormone is also responsible for synchronizing reproduction with specific external environment stimuli in order to optimize reproductive success.The aim of this study was to establish the effect of melatonin on zebrafish reproduction.Adult females were dail...

BACKGROUND Although unsaturated fatty acids such as eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (ARA, C20:4n-6), collectively known as the highly unsaturated fatty acids (HUFA), play pivotal roles in vertebrate reproduction, very little is known about their synthesis in the ovary. The zebrafish (Danio rerio) display capability to synthesize a...

OBJECTIVES It was aimed to investigate the effects of different doses of follicle stimulating hormone (FSH) and activin A on the growth and maturation of preantral mouse follicles during the in vitro culture. METHODS Preantral follicles (90-100 microm in diameter) were harvested from 6-8 week-old Syrian mice and cultured in TCM199 culture medium for 6 days to see the effect of FSH and Activin...