Effects of the External Environment Factors on the Development of Mouse Two-Cell Embryo

Background: To investigate the development of two-cell mouse embryos in vitro at different external environment factors (osmolarity) and demonstrate if the embryo at early stage of development is sensitive to osmotic stress or not. Methods: A total of 173 mouse embryos were collected during the period of January 2018 until July 2018. One NMRI male mouse was caged with the female mice CD1 for natural mating. Th e female mice were flushed of the two-cell embryos from the oviduct after 24 hours. Th e mating was confirmed by the presence of a plug in the vagina (whitish gelatine substance in the vagina) next day. Th e osmolarity values were measured by advanced micro-osmometer. One-way ANOVA test was used to compare between different values of osmolarity. Results: The findings indicated that the increased osmotic pressure can significantly affect the rate of development. The developmental rate of two-cell mouse embryos was significantly decreased when cultured in 310 milliosmole and significantly increased in 280 milliosmoles as compared to the 260 milliosmole control group (9.52 ± 16.49, P < 0.001; 83.3 ± 28.7 to 76.29 ± 31.92, P < 0.001). Conclusion: The study has concluded that the osmotic pressure can affect the rate of development and it depends on the quality of environment. Th e data observed from the mouse embryos might also be helpful in humans and shed light on the effect towards human embryos.