Effect of Protein Additives on in vitro Maturation of Egyptian Sheep Oocytes with Reference to Seasonal Variation Effects on Yield and Quality of Oocytes

The present study was designed to investigate the effect of supplementing of protein additives (PA) in forms of 10% ovine amniotic fluid (OAF), 10% fetal bovine serum (FBS) and 10% sheep serum (SS), individually to culture media (TCM-199 or RPMI-1640) on in vitro nuclear maturation (IVM) of sheep oocytes. In addition, the effect of seasonal variations on the yield and quality of recovered sheep oocytes was also evaluated. Sheep ovaries were collected from local slaughterhouse. Cumulus-oocytes complexes (COCs) and denuded oocytes (DOs) were aspirated and matured in culture media (TCM-199 or RPMI -1640) for 26-29h at 39°C under 5% CO2 in air and 95% humidity. The results showed that the supplementation of protein additives (PA) in forms of OAF, FBS or SS to culture media (TCM-199 or RPMI-1640) are required for IVM of sheep oocytes. The supplementing of PA to culture media was more efficacious in TCM-199 than RPMI-1640 for IVM of oocytes. The COCs were more response for PA than denuded oocytes. The spring was the best season for recovery of COCs which have a worthy competence to be matured in vitro. In conclusion, the study demonstrated the importance of PA with the suitable culture media during the proper season for IVM of sheep oocytes as an abundant source for production of transgenics and cloning. [Journal of American Science 2010;6(10):588-599]. (ISSN: 1545-1003).