Effect of Bovine Leukemia Inhibitory Factor on Hatching and Numbers of Inner Cell Mass and Trophectoderm of Bovine Intact and Biopsied Blastocysts

The effect of bovine leukemia inhibitory factor (bLIF) on hatching and numbers of inner cell mass (ICM) and trophectoderm (TE) of bovine intact and biopsied blastocysts was examined. Experiment 1: bovine blastocysts produced in vitro were cultured with 0, 2, 10, 25, 50 and 100ng/ml of bLIF. The hatching rate of blastocysts cultured with varied concentrations of bLIF was significantly higher than that of the blastocysts cultured without bLIF. The numbers of TE cells of surviving blastocysts cultured in medium with bLIF significantly increased compared with that cultured without bLIF. However, there were no differences in the numbers of ICM cells. Experiment 2: bovine blastocysts were biopsied and the remaining embryos were cultured for 72h with 10ng/ml of bLIF. There were no differences in survival rates of blastocysts in cultures with or without bLIF. The number of TE cells of biopsied blastocysts cultured with bLIF significantly increased compared in culture with that without bLIF. However, there were no differences in the numbers of ICM cells. These results indicate that bLIF acts on the hatching process and increases the number of TE cells.