Embryotropic effect of insulin-like growth factor (IGF)-I and its receptor on development of porcine preimplantation embryos produced by in vitro fertilization and somatic cell nuclear transfer

作者：Kim S; Lee GS; Lee SH; Kim HS; Jeong YW; Kim JH; Kang SK^*; Lee BC; Hwang WS

来源：Molecular Reproduction and Development, 2005, 72(1): 88-97.

DOI：10.1002/mrd.20327

• IGF-I
• IGF-I receptor
• porcine
• IVF
• SCNT

Insulin-like growth factor (IGF)-l is a receptor-mediated autocrine/paracrine growth/survival factor for mammalian embryo development. The present study investigated the temporal expression and regulation of porcine IGF-l receptor (IGF-IR) mRNA and the role of IGF-l on development of porcine in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos. As assessed by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), the level of IGF-IR mRNA expression was high in unfertilized oocytes, 2-cell and 4-cell embryos and gradually decreased in 8-cell embryos, morulae, and blastocysts in both IVF and SCNT series. The IVF or SCNT embryos were cultured with 0, 1, 10, 50, or 100 ng/ml IGF-l for 168 hr. Supplementing with 50 ng/ml IGF-l increased blastocyst formation and the number of cells in inner cell masses (ICMs) in both IVF and SCNT embryos. In a second experiment, more blastocysts were obtained when IVF or SCNT embryos were cultured for the first 48 hr or for the entire 168 hr with 50 ng/ml IGF-l compared to culturing without IGF-l for 48 hr or with IGF-l for the last 120 hr or without IGF-l for the entire 168 hr. Treating IVF or SCNT embryos with 50 ng/ml IGF-l significantly up-regulated IGF-IR mRNA compared to untreated control embryos. In conclusion, the present study demonstrated that IGF-IR mRNA is expressed in porcine IVF and SCNT embryos, and that IGF-l improved the developmental competence of IVF and SCNT embryos through its specific receptors.

• 出版日期2005-9