48 EFFECT OF INSULIN-LIKE GROWTH FACTOR-1 SUPPLEMENT TO NCSU-23 MEDIUM ON PREIMPLANTATION DEVELOPMENT OF PORCINE EMBRYOS DERIVED FROM IN VITRO FERTILIZATION AND SOMATIC CELL NUCLEAR TRANSFER
S. Kim A , D.H. Nam A , Y.W. Jung A , H.S. Kim A , S.H. Lee A , G.S. Lee A , S.H. Hyun A , D.Y. Kim A , S.K. Kang A , B.C. Lee A and W.S. Hwang A BA Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151–742, South Korea;
B School of Agricultural Biotechnology, Seoul National University, Suwon 441–744, South Korea. email: bule618@hanmail.net
Reproduction, Fertility and Development 16(2) 146-146 https://doi.org/10.1071/RDv16n1Ab48
Submitted: 1 August 2003 Accepted: 1 October 2003 Published: 2 January 2004
Abstract
The developmental potential of in vitro production of embryos is affected by various factors, including the culture system, oocyte quality, the presence of serum, and embryo paracrine and autocrine growth factors. Insulin-like growth factor is a good stimulator of oocyte maturation and embryo development. The present study investigated the effect of insulin-like growth factor-I (IGF-I) supplement on the preimplantation development of porcine embryos derived from in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT). Developmental competence was evaluated by monitoring the numbers of 2-cell embryos and blastocysts at Days 2 and 7, respectively. The number of total cells and inner cell mass (ICM) cells in blastocysts were counted after differential staining at Day 7. All data were analyzed by ANOVA using a Generalized Linear Model (SAS). In Experiment 1, a total of 2,462 in vitro-matured oocytes (527, 458, 498, 481 and 498, respectively) were inseminated with frozen-thawed boar semen and subsequently cultured in North Carolina State University (NCSU)-23 medium supplemented with various concentrations of IGF-1 (0, 1, 10, 50 and 100 ng mL−1). As a result, significant model effects on the development to the 2-cell stage (P = 0.033) and to the blastocyst stage (P = 0.0067) were found, and more blastocysts (16.9, 16.6, 17.5, 21.8 and 14.7 %, respectively) were obtained in medium supplemented with 50 ng mL−1 of IGF-I. Moreover, increase in the total cell number (56.5, 53.2, 74.0, 76.4 and 58.4) and ICM (6.6, 5.8, 9.3, 9.4 and 6.1) cells was observed in IVF embryos cultured in NCSU-23 medium supplemented with 50 ng mL−1 IGF-1. In Experiment 2, porcine cloned embryos were produced by our standard protocol using fetal fibroblasts as donor cells (Hyun SH et al., 2003 Theriogenology 59, 1641–1649) and cultured in NCSU-23 supplemented with the same concentration of IGF-1 as Experiment 1. As a result, a total of 501 reconstructed oocytes (99, 98, 102, 99 and 96, respectively) were cultured and significant model effects on the development to the 2-cell stage (P = 0.0179) were found. More blastocysts (10.5, 11.2, 11.8, 20.8 and 10.1%) were produced when embryos were cultured in NCSU-23 medium supplemented with 50 ng mL−1, even though no statistical significance was found (P = 0.1182). Increases in the total cell number (42.7, 46.0, 45.9, 51.1 and 38.2) and ICM cells (3.8, 3.8, 5.6, 6.6 and 4.8, respectively) were observed in cloned embryos cultured in NCSU-23 medium supplemented with 50 ng mL−1 of IGF-I. In conclusion, the present study demonstrated that IGF-1 at the concentration of 50 ng mL−1 improves the development of preimplantion embryos derived from IVF and SCNT. This study was supported by the Advanced Backbone IT Technology Development (IMT 2000-C1-1).
