THE EFFECT OF RECOMBINANT HUMAN LEUKEMIA INHIBITORY FACTOR (rhLIF) ON IN VITRO DEVELOPMENT OF MOUSE 2-CELL EMBRYOS AND THEIR ISOLATED BLASTOMERES

Abstract

In this study effect of recombinant human leukemia inhibitory factor on invitro development of 2 cells embryos and isolated blastomeres derived from mouse 2 cell embryos were investigated. Female ICR mice that were between 8 to 10 weeks old received intraperitoneal injection of 7.5 IU of PMSG for super ovulation followed by intraperitoneal administration of 7.5 IU of HCG 48 hours later. The mice were then mated to mature ICR male mice and were checked for vaginal plugs after 13-14 hours. Mice were killed 46-48 hours after HCG injection by cervical dislocation, their oviducts were removed and flushing 2 cell embryos were collected. The zona pellucida of 2 cell embryos were removed by Acid Tyrod solution and blastomeres separated with oocyte preparation pipette and then all embryos and blastomeres were cultured in Potassium Simplex Optimized Medium (KSOM) +Aminoacid (AA) different amounts of rhLIF (500IU/ml, 1000IU/ml and 1500IU/ml). Some embryos and individual blastomere also were cultured without rhLIF as control group. All samples were cultured in an incubator at 370C with 0.05 CO2 for 120 hours. The rate of embryo and individual blastomeres which reached to 2 cell, 4 cell, 8 cell and 9-16 cell were the same in all groups. However in further developmental stages, morula and blastocyst between experimental and control groups were significantly different. Therefore it may be concluded that: cultivation of isolated blastomers up to the blastocyst stage with rhLIF has stimulatory effect on the preimplantation stage (morula and blastocyst) but it has no stimulatory and inhibitory effects when was added to culture media at the early cleavage stage.