The paper describes comperatively aspects of oogenesis and folliculogenesis, oocyte and follicular growth in cattle and pigs. Moreover, gonadotropin dependent regulatory processes of the wave like pattern of follicular growth are discussed in both species as well as functional and morphological changes during oocyte maturation. Finally, time dependent processes after oecurrence of spontaneous o...

Estrogen biosynthesis and proteolysis are both important processes involved in ovarian follicular development, which may be influenced by cytochrome P450 (CYP)-dependent fatty acid metabolites. However, CYP-dependent lipid metabolism has not been characterized with respect to follicular maturation in vivo. Therefore, follicular fluid was collected in the hours before and after the LH surge in p...

the interaction between molecular biology and embryology made an extensive progress in the research on gametogenesis, fertilization and early embryogenesis in mice. in this article, molecules involving in meiotic maturation and apoptosis of oocytes, sperm-oocyte interactions and early cleavage of fertilized embryos in mice are described including our recent following experiments. 1) phosphatidy...

Gonadotropin-inhibitory hormone (GnIH), an RFamide peptide, has been found to inhibit pituitary LH secretion in avian and mammalian species. The gene encoding a putative receptor for GnIH (GnIHR) was recently identified in the chicken and Japanese quail brain and pituitary gland. GnIHR appears to be a seven-transmembrane protein belonging to a family of G-protein-coupled receptors. In the prese...

Background: Polycystic ovary syndrome (PCOS) is a common cause of infertility often responsive to treatment with oral ovulation induction agents. PCOS patients are typically characterized by producing an increased number of oocytes that they are often of poor quality, leading to lower fertilization, cleavage and implantation rates. Recently data involve functional associations between endocrine...

This study examined effects on the developmental competence of pig oocytes after somatic cell nuclear transfer (SCNT) or parthenogenetic activation (PA) of : 1) co-culturing of oocytes with follicular shell pieces (FSP) during in vitro maturation (IVM); 2) different durations of maturation; and 3) defined maturation medium supplemented with polyvinyl alcohol (PVA; control), pig follicular fluid...

In hens, the ovarian follicles committed to ovulation are arranged in an ordered follicular hierarchy. In standard broiler breeders hens genetically selected for high growth rate the reproductive function is clearly dysfunctional. Feed restriction is needed during reproductive development to limit the formation of excessive numbers of ovarian yellow follicles arranged in multiple hierarchies. T...

BACKGROUND New data suggests that endothelial cells (ECs) elaborate essential "angiocrine factors". The aim of this study is to investigate the role of activated ovarian endothelial cells in early in-vitro follicular development. METHODS Mouse ovarian ECs were isolated using magnetic cell sorting or by FACS and cultured in serum free media. After a constitutive activation of the Akt pathway w...

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 µm 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 a. ...

In vitro culture of human ovarian tissue the following cryopreservation is proposed for follicular development. There are no techniques that guarantee successful maturation of the follicles within the excised tissue. The viability of cultured human ovarian tissue improved by adding some growth factors to the culture media. The efficiency of vitrification as the cryopreservation method for human...