Document Type : Original Article
Department Of Animal Sciences , Faculty Of life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
School of pharmacy and Bioengineering , Keele University, ST58G, UK
Objective: In vitro maturation (IVM) and cryopreservation of oocytes are two important parts of assisted reproductive technology (ART), but their efficacy is low. This study aimed to improve the quality of in vitro vitrified-warmed maturated oocytes using granulosa cell conditioned medium (GCCM).
Materials and Methods: In the experimental study, fresh/non-vitrified and vitrified-warmed mouse germinal vesicle (GV)
oocytes (as F and V) were in vitro maturated using basal medium (BM) and also BM supplemented with 50% GCCM as treated groups (GM), and categorized as FBM, FGM, VBM and VGM groups, respectively. The rate of successful IVM (MII oocyte formation), mitochondrial membrane potential and the viability of MII oocytes were determined using inverted microscopy, JC-1 and trypan blue staining. Then, the rate of in vitro fertilization (IVF) and subsequent two-cell embryo formation was calculated. Finally, the expression levels of Oct4, Sox2, Cdk-2, Gdf9, Integrin beta1 and Igf2 were analyzed using real-time polymerase chain reaction (PCR) in MII oocytes and two-cell embryos.
Results: These analyses showed that GCCM significantly increased the IVM rate, oocyte meiotic resumption and mitochondrial membrane potential (P<0.05). In addition, the rate of IVF and two-cell embryo formation was significantly
higher in FGM and VGM compared to FBM and VBM (P<0.05). Interestingly, GCCM significantly affected the expression
of the studied genes.
Conclusion: Our findings suggest that GCCM might be useful for improving the efficiency of IVM and the subsequent