EFFECT OF TCM-199 AND SYNTHETIC OVIDUCTAL FLUID (SOF) MEDIUM AND CYSTEAMINE SUPPLEMENTATION TO IN VITRO MATURATION MEDIA ON MATURATION, CLEAVAGE RATE AND SUBSEQUENT EMBRYONIC DEVELOPMENT OF BUFFALO OOCYTES

The present study has been undertaken to study the effect of TCM-199 and synthetic oviductal fl uid (SOF) medium and the infl uence of cysteamine (100 μM) supplementation to IVM medium on maturation, cleavage and subsequent embryonic development of buffalo oocytes. In the present study it was observed that buffalo oocytes showed no signifi cant variation in the percent of cumulus cell expansion when matured in TCM199 and SOF media. The mean percent of cleavage rate and subsequent development to morula in buffalo oocytes matured in TCM-199 and SOF media were 28.06 + 2.19, 10.20 + 0.91 and 28.99 + 0.66, 10.65 + 0.40, respectively. There was no signifi cant difference with regard to cleavage rate and subsequent development to morula when buffalo oocytes were matured in TCM-199 and SOF media. The percentage of oocytes that developed to morulae was signifi cantly higher for oocytes matured in TCM-199 medium containing cysteamine (14.56 + 1.06 vs 10.20 + 0.91) and in SOF medium supplemented with 100 μM of cysteamine (13.97 + 0.80 vs 10.65 + 0.40) compared to their respective controls whereas the cysteamine supplementation to the IVM (TCM-199) medium of buffalo oocytes insignifi cantly increased the cleavage rate when compared with control (33.54 + 1.54 vs 28.06 + 2.19) and subsequent development of cleaved embryos to the morula stage (43.40 + 2.48 vs 36.36 + 1.65). The cysteamine supplementation to the SOF as IVM medium of buffalo oocytes also insignifi cantly increased the cleavage rate when compared with control (33.09 + 1.08 vs 28.99 + 0.66) and subsequent development of embryos to the morula stage (42.22 + 3.12 vs 36.73 + 1.12). Even though the effect of cysteamine supplementation to IVM was insignifi cantly higher with regard to cleavage rate and development of early embryos to morulae, the percentage of oocytes that developed to morulae was signifi cantly higher for oocytes matured in TCM-199 medium containing cysteamine (14.56 + 1.06 vs 10.20 + 0.91) and in SOF medium supplemented with 100 μM of cysteamine (13.97 + 0.80 vs 10.65 + 0.40) compared to their respective controls, which could be attributed to cumulative effect (positive infl uence) of cysteamine on both the fertilization process and early embryonic development. The benefi cial effect of cysteamine on embryo development might be mediated by an increase in glutathione (GSH) synthesis. Increased oxidative stress appears to be a major factor impairing in vitro mammalian embryo development. The oocytes and embryos of buffaloes are more sensitive to oxidative stress because of their higher lipid content which may be a cause of (species-specifi c) developmental block to embryo development. The effect of EFFECT OF TCM-199 AND SYNTHETIC OVIDUCTAL FLUID (SOF) MEDIUM AND CYSTEAMINE SUPPLEMENTATION TO IN VITRO MATURATION MEDIA ON MATURATION, CLEAVAGE RATE AND SUBSEQUENT EMBRYONIC DEVELOPMENT OF BUFFALO OOCYTES Ch. Srinivasa Prasad*, A. Palanisamy, V.S. Gomathy, S. Satheshkumar, A. Thangavel and G. Dhinakar Raj Centralized Embryo Biotechnology Unit, Tamila Nadu Veterinary and Animal Sciences University, Chennai, India, *E-mail: spchigurupati@rediffmail.com, spchigurupati@gmail.com Buffalo Bulletin (September 2013) Vol.32 No.3 Buffalo Bulletin (September 2013) Vol.32 No.3 183 oxidative stress could be attenuated by effi cient antioxidants such as GSH which scavenge reactive oxygen species (ROS). Embryos are capable of synthesizing GSH after the activation of the embryonic genome and the eight-cell block may be correlated to low intracytoplasmic concentration of GSH. Adequate amounts of GSH need to be synthesized during in vitro maturation of oocytes in order to support development up to the stage at which embryos acquire the biosynthetic ability.