|Jung, S -|
|Bowers, S -|
|Willard, S -|
Submitted to: Journal of Animal and Veterinary Advances
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 22, 2009
Publication Date: September 1, 2009
Citation: Jung, S.Y., Bowers, S.D., Willard, S.T. 2009. Simulated Microgravity Influences Bovine Oocyte In Vitro Fertilization and Preimplantation Embryo Development. Journal of Animal and Veterinary Advances 8(9):1807-1814. Interpretive Summary: Bovine embryo culture in the laboratory is sometimes difficult, and efforts are being made to try and evaluate alternate environments to improve embryo fertilization rates and the culture environment for improved embryo production. Given the nature of the uterine environment, we chose to evaluate whether a simulated microgravity environment may be more suitable for embryo culture and developmental processes. In contrast, our results indicated that simulated microgravity environments in fact have a negative impact on bovine in vitro fertilization and pre-implantation embryo development. Therefore, alternate environments should be pursued regarding novel embryo culture systems, although the current results raises interesting questions concerning why microgravity-like environments may be deleterious to fertilization events and embryo development in general.
Technical Abstract: 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™ (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.