Gamete Biology

Effect of Insulin-Like Growth Factor-I During Preantral Follicular Culture on Steroidogenesis, In Vitro Oocyte Maturation, and Embryo Development in Mice

Abstract
Insulin-like Growth Factor-I (IGF-I) is involved in the regulation of ovarian follicular development and has been shown to potentiate the FSH-responsiveness of granulosa cells from preantral follicles. The aim of the present study was to investigate the effect of IGF-I during preantral follicular culture on steroidogenesis, subsequent oocyte maturation, fertilization and embryo development in mice. Preantral follicles were isolated mechanically and cultured during 12 days in a simplified culture medium supplemented with 1% fetal calf serum, r- FSH, transferring and selenium. In these conditions, follicles were able to grow and to produce oocytes that could be matured and fertilized. The first experiment analyzed the effect of different concentrations of IGF-I (0, 10, 50 or 100 ng/ml) added to the culture medium on the follicular survival, steroidogenesis and the oocyte maturation process. The presence of IGF-I during follicular growth increased the secretion of estradiol, but had no effect on the subsequent oocyte survival and maturation rates. In the second experiment, IGF-I (0 or 50 ng/ml) was added to the culture medium during follicular growth, oocyte maturation or both, and subsequent oocyte fertilization and embryo development rates were evaluated. Oocyte fertilization rates were comparable in the presence or the absence of IGF-I. However, the blastocyst development rate was enhanced after follicular culture in the presence of IGF-I. Moreover, the total cell number of the blastocysts observed after differential labelling staining was also higher when follicles were cultured or matured in the presence of IGF-I.

Key words: Ovary • Developmental biology • Follicle • In vitro fertilization • Insulin-like growth factor receptor

This article has been cited by other articles:

				O. Lacham-Kaplan, H. Chy, and A. Trounson Testicular Cell Conditioned Medium Supports Differentiation of Embryonic Stem Cells into Ovarian Structures Containing Oocytes Stem Cells, February 1, 2006; 24(2): 266 - 273. [Abstract] [Full Text] [PDF]

				I Demeestere, J Centner, C Gervy, Y Englert, and A Delbaere Impact of various endocrine and paracrine factors on in vitro culture of preantral follicles in rodents Reproduction, August 1, 2005; 130(2): 147 - 156. [Abstract] [Full Text] [PDF]

				A. S. Chang, A. N. Dale, and K. H. Moley Maternal Diabetes Adversely Affects Preovulatory Oocyte Maturation, Development, and Granulosa Cell Apoptosis Endocrinology, May 1, 2005; 146(5): 2445 - 2453. [Abstract] [Full Text] [PDF]