Localization of zona pellucida glycoprotein 3 (pZP3) and integrin-beta-2 (ITGB2) in porcine oocytes cultured in vitro

摘要

It has been clearly demonstrated in several studies that zona pellucida is modificated during oogenesis and folliculogenesis, important stages of mammalian oocytes maturation. However, little is known to date about differential expression and various distributions of proteins involved in fertilization, e.g. zona pellucida glycoprotein 3 (pZP3), integrin-beta-2 (ITGB2) within the porcine oocytes. Since the morphology of the female gamete significantly influences the ability of oocytes for maturation and fertilization, this study aimed to investigate the distribution of pZP3 and ITGB2 in four morphologically different porcine oocytes using confocal microscopic observations.The porcine COC's were morphologically evaluated in a four graded scale with special relation to colorization of cytoplasm and cumulus cell layers, cultured in culture medium NCSU-23 for 44 h at 38 degrees C, and then subsequently fixed with anti-pZP3 and anti-ITGB2 antibodies, and analyzed using confocal microscopic observations.Consequently, we found that pZP3 protein was localized in oocytes graded as I and II in zona pellucida and cytoplasm. In oocytes graded as Ill and IV, pZP3 was distributed in the cytoplasm. Regarding the ITGB2, in oocytes graded as I the zona pellucida localization was observed. In the other grades of oocytes a strong cytoplasmic expression of ITGB2 was detected.In conclusion, the expression of both pZP3 and ITGB2 proteins as well as the differential distribution of these proteins within the female gamete are associated with the morphological type of porcine oocytes.