Final oocyte maturation

Thorsen, A. and H.J. Fyhn. Final oocyte maturation in vivo and in vitro in marine fishes with pelagic eggs yolk protein hydrolysis and free amino acid content. J. Fish. Biol. 48 1195-1209, 1996. 

Bovine in vitro maturation assay blVM Successful achievement of the maturation-stage metaphase II (completion of meiosis up to metaphase II) Oocyte final maturation... 

The matured oocytes were visually judged on the basis of their external characteristics (e.g. expansion of the cumulus cells and presence of smaller and darker oocytes), as indicators of degree of maturity. The selected oocytes were then placed in a culture Petri-dish containing TALP-hepes medium, washed two times in TALP-hepes and one time in Fert-Talp medium. 15-20 oocytes were transferred into the 50p.l droplet of Fert-Talp media that was supplemented with caffeine and Heparin. Then a final volume of the prepared semen, containing 1-2 x 10 sperm cells/ml, was added to the 50pl droplet containing the matured oocytes. The in-vitro fertilization was performed in media supplemented with 20 pg of heparin/mL and 6 mg/mL of fatty Iree-acid BSA fraction, covered with mineral oil for 18 h in a humidified atmosphere of 5% CO2 and at 39 C in air. 

Like urofollitropin, it is marketed for enhancing the development of multiple follicles that can then be induced to ovulate, via hCG administration, so that the oocytes can be collected for IVF. It also is used in treating women who wish to become pregnant and are anovulatory because of polycystic ovary syndrome, in whom it can enhance follicle maturation before hCG administration for final ovulation. All commercial products can be administered by SC injection. The RFF notation signifies Revised Formulation Female, and the RFF Pen notation indicates a prefilled, ready-to-use device designed to make self administration easier. 

Goetz, F. W., 1983, Hormonal control of oocyte final maturation and ovulation in fishes, Fish Physiology, Vol. IXB, Behavior and Fertility Control, W. S. Hoar, D. J. Randall, and E. M. Donaldson, eds.. 

The brief discussion above serves to point out the potential importance to early development of the several events associated with maturation in vertebrates. The present review summarizes experiments carried out over the last several years on the nature and regulation of these events in amphibians. This chapter is divided into three general sections. First, several descriptive aspects of the maturational period will be discussed, including information concerned with the existence and distribution of morphogenetic substances present in the GV and cytoplasm of ovarian and maturing oocytes. The second part is concerned with macromolecular synthesis during maturation and its possible role in early development. Finally, there will be a discussion of current data relating to the mechanism by which hormones induce the processes of maturation. 

Azadirachtin, applied topically to final-instar larvae of lepidopteran insects, affects oogenesis and reproductive maturation in subsequent female moths (74). Moths obtained from such treated larvae developed fewer mature oocytes, possibly as a result of interference of azadirachtin with vitellogenin synthesis and/or its uptake by developing oocytes. Larval treatments also cause decreased viability of emerging larvae from affected eggs. 

Ghosh, S. Thomas, P. 1995. Antagonistic effects of xenobiotics on steroid-induced final maturation of Atlantic croaker oocytes in vitro. Marine Environmental Research, v.39, p. 159-163. 

---