부산대학교 도서관

The in vitrodevelopmental abilities of porcine oocytes are generally increasing steadily at a similar ratio to those of in vivoembryos. However, it has been suggested that the in vitroculture system for the development of porcine embryos is not optimal. In this study, we investigated the effect of 2 oxygen concentrations (5 and 20%) on porcine embryo development during in vitromaturation and in vitroculture and analyzed differences in gene expression of resulting blastocysts. Oocytes were recovered by aspiration of slaughterhouse ovaries and then matured in tissue culture medium (TCM) 199 supplemented with 10% porcine follicular fluid (pFF), epidermal growth factor (EGF), insulin, pyruvate, cystine, and gonadotropin. Matured oocytes were then activated parthenogenetically, cultured in PZM-3 media for 7 days. In vitromaturation (M group) of oocytes was carried out under two oxygen concentration (5 and 20%) in terms of nuclear maturation (polar body extrusion; Exp. 1). The developmental differences between 5% oxygen culture group and 20% oxygen culture group during in vitroculture (C group) of embryos after parthenogenetic activation was investigated in terms of first cleavage and blastocyst formation (Exp. 2). RelativemRNA abundance of multiple genes in blastocysts was analyzed for transcript abundance of genes related with metabolism (GLUT1, LDHA), oxidative response (MnSOD, GPX1), apoptosis (BAX, Bcl2), and developmental competence (CCNB1, IGF2R; Exp. 3). The results show there were no significant differences in maturation rate between 2 oxygen concentrations during in vitromaturation (83 v.86%). It was thought that cumulus cells surrounding oocytes might have attenuated oxidative stress, but number of resulting blastocysts were (P<0.05) increased in 5% IVC group when compared with 20% IVC group (18.67 v.14.09%, respectively). Moreover, the M20C5 group (23.01%) had a beneficial effect on in vitroculture compared with M5C5 (14.32%), M5C20 (10.30%), and M20C20 (17.88%) groups. Total cell numbers were not significantly different among groups. According tomRNA abundance data of multiple genes, each group altered the expression of genes in various patterns. Therefore, it could be concluded that high oxygen tension during in vitromaturation and low oxygen tension during in vitroculture might alter the expression of multiple genes related to oocyte competence and improve (P<0.05) embryo development, but not blastocyst quality. This study was supported by MKE (#2009-67-10033839, #2009-67-10033805), NRF (#M10625030005-508-10N25), BK21 for Veterinary Science, IPET (#109023-05-1-CG000), and Hanhwa L&C. [ABSTRACT FROM AUTHOR]