Developing a culture system for preantral follicles has important biotechnological implications due to the potential to produce a large number of oocytes for embryo production and transfer. To accomplish this goal, the present study was aimed to culture preantral follicles in the presence of different media, sera and FSH concentrations. Six-week-old preantral follicles (95 ± 5 µm) were cultured...

Background: This study was carried out to evaluate the pattern of reactive oxygen species (ROS) variations during in vitro oocyte maturation and embryo development in sheep, and to investigate whether embryo culture condition and the presence of cell-permeable superoxide dismutase mimetic [Manganese (III) meso-tetrakis (4-benzoic acid) porphyrin (MnTBAP)] can influence ROS pattern. Materials an...

During progesterone-induced meiotic maturation of Xenopus oocytes in vitro, 7 morphological stages were defined. Using cytological analysis, nuclear breakdown was divided into three stages. Stage 1 corresponded to basal germinal vesicle breakdown. Stage 2 was characterized by the advent and development of a fibrillar network formed by microtubules at the basal part of the nucleus. Below, a lame...

Keeping the intact germinal vesicle (GV) is essential for maintaining the capacity of mammals including human. It is maintained by very complex procedures along with folliculogenesis and is a critical step for getting competent oocyte. So far, a few mechanisms involved in folliculogenesis are known but GV arrest mechanisms are largely unrevealed. Cyclic AMP, a adenosine derived substance, have ...

Germinal vesicle breakdown (GVBD) of bovine oocytes was completely blocked by cycloheximide added to culture medium at concentrations of 1-20 micrograms/ml. Nevertheless, under such conditions a certain degree of chromatin condensation inside the germinal vesicle was observed. The inhibitory effect was not influenced by the presence or absence of cumulus cells and was fully reversible; but the ...