Abstract: The objective of this study was to evaluate the effects of Percoll sedimentation treatment of porcine oocytes before In vitro Maturation (IVM) on the meiotic competence of the oocytes. Cumulus-oocyte Complexes (COCs) with uniform ooplasms and compact cumulus cells obtained from porcine ovaries were placed on the surface of Percoll solutions of various concentrations (5, 10, 15, 20 and 25%) in a petri dish. Only the COCs that settled in the dish within 3 min were transferred into maturation medium. At the end of the IVM culture, the nuclear status of the oocytes was assessed. The proportion of COCs that settled decreased with an increase in the concentration of the Percoll solution. When the COCs were treated with less than 10% Percoll solution, more than half the total number of COCs settled. In contrast, the proportion of COCs that settled was lower (p< 0.01) in the 20 and 25% Percoll solutions (12 and 1%, respectively) than in Percoll solutions with lower concentrations (49-90%). The proportion of oocytes that underwent germinal vesicle breakdown and reached metaphase II after the Percoll treatment and subsequent IVM culture did not differ among the 5, 10 and 15% Percoll solution groups. Moreover, it also did not differ from that of the control oocytes that were not treated with Percoll. In conclusion, the selection of oocytes by Percoll sedimentation treatment does not improve the rates of nuclear maturation of porcine oocytes and decreases the total number of COCs available for IVM culture.
Morteza Yavari , Akiko Fujii , Ryohei Shimizu , Aya Ito , Yukine Kaedei , Yasuhiro Morita , Fuminori Tanihara and Takeshige Otoi , 2007. Meiotic Competence of Porcine Oocytes after Percoll Sedimentation Treatment for Oocyte Selection . Journal of Animal and Veterinary Advances, 6: 1333-1336.