Effects of insulin-like growth factor 1, leukemia inhibitory factor, and basic fibroblast growth factor on goat oocyte maturation and early embryonic development in vitro

Abstract

In this study, we investigated the effects of insulin-like growth factor 1 (IGF-1), leukemia inhibitory factor (LIF), and basic fibroblast growth factor (bFGF) on the in vitro maturation of goat oocytes and early embryonic development of in vitro-fertilized (IVF) oocytes. We also aimed to prepare an efficient in vitro maturation culture system for goat oocytes as a technical basis for improving both the quality of goat oocytes and the efficiency of embryo production in vitro. The experimental results revealed that the addition of bFGF (40 ng/mL), LIF (20 ng/mL), and IGF-1 (20 ng/mL) to the maturation medium improved the maturation rate of goat oocytes. Compared with the control group, the in vitro maturation rate of oocytes (83.0% vs. 70.93%, P < 0.05) and the development rate of IVF blastocysts (45.88% vs. 35.81%, P < 0.05) in the bFGF, LIF, and IGF-1 (FLI) group were significantly increased. The total number of developing blastocysts (114.40 vs. 83.20, P < 0.05) and the ratio of inner cell mass cells (39.50 vs. 25.33, P < 0.05) were also significantly higher in the FLI group than in the control group. Evaluation of maternal gene expression revealed that FLI could significantly increase the expression levels of DNMT1, ZAR1, and NLRP5 and cumulus cell expansion genes PTX3, TNFAIP6, PTGS2, and HAS2 in mature oocytes (P < 0.01). We indirectly proved that bFGF, LIF, and IGF-1 support goat oocyte maturation and early embryonic development. In summary, this study established a reliable and efficient in vitro goat oocyte maturation culture system using bFGF, LIF, and IGF-1. The results of this study can serve as a technical basis for improving the quality of goat oocytes matured in vitro, potential of early embryonic development, IVF of goat embryos, and in vitro production of other livestock.