Simulated Microgravity Influences Bovine Oocyte in vitro Fertilization and Preimplantation Embryo Development

The aim of this study was to investigate, whether in vitro fertilization and preimplantation embryos exposed to a simulated microgravity environment in vitro would improve, or be deleterious to their fertilization and embryonic development. A Rotating Cell Culture System(TM) (RCCS) bioreactor with a High Aspect Ratio Vessel (HARV) was used to simulate a microgravity environment. In vitro Fertilization (IVF) and Culture (IVC) were conducted in standard microdrop culture method conditions (Control) and simulated microgravity conditions; HARV rotated at 34 rpm (high speed) and at 3.7 rpm (Low speed) on a horizontal axis. Embryonic development rates were determined during IVF (experiment 1), during IVC at presumptive zygote stage (experiment 2) and IVC at 2-8 cell stages of embryo development (experiment 3). For IVF studies (experiment 1), 77.3% of bovine oocytes were fertilized in the Control group; however, bovine oocytes and sperm fertilization did not occur in high and low speed groups. Moreover, none of the presumptive zygotes (experiment 2) and 2-8 cell stage embryos (experiment 3) cultured in high and low speed groups were able to develop to the further stages. These results indicate that simulated microgravity environments have a negative impact on bovine In vitro fertilization and preimplantation embryo development.