Document Type : Original Article
Anatomy Department, Tehran University of Medical Sciences Faculty of Medicine, Tehran, Iran
Introduction: To improve the development of embryo in vitro several attempts have been made, including the application of leukemia inhibitory factor (LIF). This factor plays an important role in embryo development and has been shown to enhance in vitro development rate in sheep and mice. There is controversy regarding the effect of LIF on the different stages of embryo development. The aim of this study was to investigate the effect of rhLIF on development of 2-cell mouse embryo.
Material and Methods: Female ICR mice aged 8 to 10 weeks received intraperitoneal injection of 7.5 IU of pregnant mare serum gonadotropin (PMSG) for superovulation. This was followed by intraperitoneal administration of 7.5 IU of Human Chorionic Gonadotropin (HCG) 48 hours later. The mice were then mated with mature ICR male mice and were checked for vaginal plaque 13-14 hours later. Mice were killed 46-48 hours after HCG injection by cervical dislocation. After removing oviducts two cell embryos were collected by flushing technique and cultured in KSOM medium with different dosage of LIF (1500 IU/ml, 1000IU/ml , 500IU/ml). Also some embryos were cultured without LIF as control. All embryos were cultured in an incubator at 37ْc with %5 co2 for 120 hours. Embryo development was evaluated daily by obserunig the marphology using an invert microscope. Development of the embryos were recorded 24,48, 72, 96 and 120 hours later.
Results: The rate of embryos reaching four cell, 8 cell and 6-9 cell stages were the same in all groups. But in further developmental stages such a compacted morula, blastocyst and hatching blastocyst statistically significant differences were seen between case and control groups.
Conclusion: The recombinant human leukemia inhibitory factor (rhLIF) could be effective to improve in vitro development of mouse embryo.