Pakistan Veterinary Journal (Apr 2011)
Effect of Somatic Cell Types and Culture Medium on in vitro Maturation, Fertilization and Early Development Capability of Buffalo Oocytes
Abstract
This study was designed to evaluate the efficacy of different somatic cell types and media in supporting in vitro maturation (IVM), in vitro fertilization (IVF) and early embryonic development competence of buffalo follicular oocytes. Cumulus oocyte complexes were collected for maturation from follicles (>6mm) of buffalo ovaries collected at the local abattoir. Oocytes were co-cultured in tissue culture medium (TCM-199) with either granulosa cells, cumulus cells, or buffalo oviductal epithelial cells (BOEC) @ 3x106 cells/ml or in TCM-199 without helper cells (control) at 39°C and 5%CO2 in humidified air. Fresh semen was prepared in modified Ca++ free Tyrode medium. Fertilization was carried out in four types of media: i) Tyrode lactate albumin pyruvate (TALP), ii) TALP+BOEC, iii) modified Ca++ free Tyrode and iv) modified Ca++ free Tyrode+BOEC. Fertilized oocytes were cultured for early embryonic development in TCM-199 with and without BOEC. Higher maturation rates were observed in the granulosa (84.24%) and cumulus cells (83.44%) than BOEC co culture system (73.37%). Highest fertilization rate was obtained in modified Ca++ free Tyrode with BOEC co culture (70.42%), followed by modified Ca++ free Tyrode alone (63.77%), TALP with BOEC (36.92%) and TALP alone (10.94%). Development of early embryos (8-cell stage) improved in TCM-199 with BOEC co culture than TCM-199 alone. From the results of this study, it can be concluded that addition of somatic cells (granulosa cells, cumulus cells) results in higher maturation rates of buffalo follicular oocytes than BOEC co culture system, while fertilization rate improved in modified Ca++ free Tyrode with and without BOEC. Addition of BOEC to TCM-199 improved the developmental capacity of early embryo.
