Effects of leukemia inhibitory factor and insulin-like growth factor-I on the cell allocation and cryotolerance of bovine blastocysts

Abstract

The present study examined the developmental capacity and cryotolerance of cultured bovine embryos in defined media (synthetic oviduct fluid, SOF) supplemented with insulin-like growth factor I (IGF-I) and leukemia inhibitor factor (LIF). The objectives of the present study were: (1) to examine the effects IGF-I and LIF on bovine embryo development potential and (2) to investigate the cryotolerance and survivability of vitrified blastocysts obtained from embryos cultured in a defined media. We studied the development of bovine embryos produced in vitro and cultured (in four different treatments) until Day 7 after fertilization. In Experiment 1, zygotes were cultured to the blastocyst stage and differentially stained for determine the count of cells. In Experiment 2, zygotes were vitrified before staining. LIF alone or combined with IGF-I was significantly effective on in vitro bovine embryo development especially ratio to reach blastocyst. The cells for both ICM and TE decreased by the effect of freezing in all treatment groups in the Experiment 2 compared with Experiment 1. Interestingly, the LIF treatment showed fewest variations. In addition to this, for average number of ICM and TE cells, LIF treatment showed fewest variation compared with other treatments (ICM: 23.5 vs 19.5, TE: 53.6 vs 51). These results are the first to demonstrate that the addition of IGF-I along with LIF to the culture medium was found to be beneficial for bovine embryonic development based on cellular cryotolerance after vitrification.