THE EFFECT OF CHANGES IN CULTURE MEDIA, pH AND TEMPERATURE ON IN VITRO FERTILIZATION AND PREIMPLANTATION EMBRYONIC DEVELOPMENT OF MICE

The present study was conducted to investigate the effect of different types of culture media, degrees of temperature of culture medium and wide range of pH within culture medium on the percentages of in vitro fertilization of mouse oocytes and embryonic development. Nine hundred and twenty four oocytes were recovered from eighty one superovulated mice. Groups of mature oocytes were incubated with active spermatozoa within different culture media (Ham’s F-10, Medi-Cult. IVF, TCM-199, Earl’s + TCM-199 and RPMI-1640) at different degrees of temperature (36, 37, 38 and 39), as well as, the pH of culture medium was changed (range: 6.9-8.1) in 5% CO2 for 18-20 hour. Percentages of in vitro fertilization and abnormal embryonic development were assessed. The best results for IVF and normal embryonic development were achieved with RPMI-1640 medium at temperature 37 oC and acidity (7.3-7.4) of medium. However, best results for in vitro development of mouse embryos were obtained by using TCM-199 medium and Ham’s F-10 medium at temperature 36 oC and acidity (7.3-7.4). In conclusion, the mouse spermatozoa and oocytes are highly sensitive to changes in the environmental conditions. In addition, conditions of culture medium and its selection are may be the main limited factor for improvement in vitro fertilization and embryonic development in mice. Further biochemical and molecular studies are recommended to assess the effect of culture medium on content of RNA and protein synthesis of different stages of mouse embryo.