Relevance of LIF and EGF on Mouse Preimplantation Embryo Development

Objective: recent evidence suggests that leukemia inhibitory factor (l1f), a member ofinterleukin-6 family, has biological actions on preimplantation embryo development alsoit is established that epidermal growth factor (egf), a strong mitosis-promoting agent,improves the preimplantation embryo development by increasing the cell metabolism andproliferation. the purpose of the present study is to investigate the effects of these factors,alone and in combination together, on preimplantation and development of the embryo.materials and methods: six to eight weeks old nmri mice were super ovulated by injectionof 10lu pmsg and 10lu hcg, then the mated mice were killed 46 hours later. theiroviducts were flushed, two-cell embryos collected and divided randomly to the four groupsas following: control, treatment 1 (l1f), treatment 2 (egf), treatment 3 (l1f+egf). in eachgroup, the embryos were cultured in an incubator at 3rc with 5% co and 90% humidityfor 72hrs. the state of embryo development was evaluated in 24,3~,48,60 and 72hrsfollowing the embryos cultures. by the end of the cultures, cell apoptosis was studiedby the terminal deoxynucleotidyl transferas-mediated dutp nick end-labeling (tunel)technique.results: significant difference was detected in the rate of hatching in the l1f and l1f+egfgroups. this difference was also seen in the rate of blastocyst formation after 36hrs(p(less than)0.05) and in the average of the total cell number (p(less than)0.05) after 72hrs. in comparison tothe apoptotic index, there was no significant difference between the control and treatmentgroups.conclusion: the findings in this study show a beneficial effect of l1f and egf on theblastocyst formation, hatching and its total cell numbers in vitro.