The Effect of Hypoxia Condition on NMRI Mouse Two-cell Embryo Development

Many factors can influence the quality of embryos produced in vitro. Oxygen concentration is one of these environment parameters which at its high level can induce the production of reactive oxygen species (ROS. causing detrimental effects on embryo. Previous observations have shown that pronuclear stage is the critical time of embryo development, which is affected by oxygen toxicity more than other stages, so that destructive impacts of oxygen may disappear, when in vitro culture initiates from next stages. In this regard, the present study was conducted to compare the effects of two oxygen concentration, atmospheric (20% O2) and hypoxic (5% O2. on development of 2-cell embryos to the blastocyst stage. 2-cell embryos were divided randomly into 2 groups including: hypoxic and atmospheric groups, and were cultured to the blastocyst stage under mentioned conditions. Finally, the blastocysts quality was evaluated in terms of blastocyst formation, hatching rate, cell number and implantation rate after embryo transfer. The results showed a significant increase in the blastocyst formation, hatching and implantation rates in the hypoxic group compared to atmospheric one (P