Journal of Animal Science, Vol 73, Issue 4 1152-1163, Copyright © 1995 by American Society of Animal Science

JOURNAL ARTICLE

Serum hormones, follicular fluid steroids, insulin-like growth factors and their binding proteins, and ovarian IGF mRNA in sheep with different ovulation rates

L. J. Spicer, S. E. Echternkamp, E. A. Wong, D. T. Hamilton and R. K. Vernon
Department of Animal Science, Oklahoma State University, Stillwater 74078, USA.

Ovulation rate, serum hormone concentrations, follicular fluid (FFL) concentrations of steroids and IGF, IGF binding protein (IGFBP) activity in FFL, and follicular IGF-I and -II mRNA were compared during the follicular phase among five genotypes of ewes: Finn (F), Composite III (C), 1/2 Booroola Merino (B) x 1/2 F (B x F), 1/2 F x 1/2 C (F x C), 1/2 B x 1/2 C (B x C). Composite III ewes were a Columbia x Suffolk x Hampshire crossbred. Ovulation rates for F (n = 7), C (n = 5), B x F (n = 6), F x C (n = 3), and B x C (n = 8) ewes were 3.1, 1.6, 3.8, 2.9, and 2.9 (Pooled SEM = .5), respectively. Concentrations of IGF-I in FFL were 53% greater (P < .05) in large (> or = 4.1 mm) than in small (< 4.1 mm) follicles but did not differ (P > .10) among genotypes. In contrast, FFL IGF-II concentrations were greater (P < .05) in B x C and B x F ewes than in C or F x C ewes but did not differ between small and large follicles. Ligand blotting revealed that IGFBP activity of three species (34, 27 to 29, and 24 kDa) were lower (P < .05) in FFL of large than in FFL of small follicles but did not differ (P < .10) among genotypes. Follicular wall IGF-I mRNA and IGF-II mRNA was detected in 5 and 32% of the samples from preovulatory follicles, respectively, using reverse transcriptase-PCR and ethidiumbromide staining. Ovarian IGF-I mRNA levels, assessed by Northern analysis, in B x F and B x C ewes were greater (P < .05) than those in C ewes; ovarian IGF-I mRNA levels in F and F x C ewes were intermediate and did not differ (P > .10) from those in C ewes. Small follicles from B x C and B x F ewes had severalfold greater (P < .05) estradiol concentrations than those from F or C ewes, whereas large follicles from B x F ewes had twice (P < .05) the estradiol concentrations of follicles from F or C ewes. Progesterone in FFL did not differ among genotypes. Serum LH, FSH, inhibin, IGF-I, and progesterone did not differ (P > .10) among genotypes.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				K. Hayashi, K. D Carpenter, T. H Welsh Jr, R. C Burghardt, L. J Spicer, and T. E Spencer The IGF system in the neonatal ovine uterus Reproduction, March 1, 2005; 129(3): 337 - 347. [Abstract] [Full Text] [PDF]

				M Munoz-Gutierrez, D Blache, G B Martin, and R J Scaramuzzi Ovarian follicular expression of mRNA encoding the type I IGF receptor and IGF-binding protein-2 in sheep following five days of nutritional supplementation with glucose, glucosamine or lupins Reproduction, December 1, 2004; 128(6): 747 - 756. [Abstract] [Full Text] [PDF]

				L. J. Spicer Proteolytic Degradation of Insulin-Like Growth Factor Binding Proteins by Ovarian Follicles: A Control Mechanism for Selection of Dominant Follicles Biol Reprod, May 1, 2004; 70(5): 1223 - 1230. [Abstract] [Full Text] [PDF]

				S. E. Echternkamp, A. J. Roberts, D. D. Lunstra, T. Wise, and L. J. Spicer Ovarian follicular development in cattle selected for twin ovulations and births J Anim Sci, February 1, 2004; 82(2): 459 - 471. [Abstract] [Full Text] [PDF]

				T. R. Davidson, C. S. Chamberlain, T. S. Bridges, and L. J. Spicer Effect of Follicle Size on In Vitro Production of Steroids and Insulin-Like Growth Factor (IGF)-I, IGF-II, and the IGF-Binding Proteins by Equine Ovarian Granulosa Cells Biol Reprod, June 1, 2002; 66(6): 1640 - 1648. [Abstract] [Full Text] [PDF]

				G. Carneiro, P. Lorenzo, C. Pimentel, L. Pegoraro, M. Bertolini, B. Ball, G. Anderson, and I. Liu Influence of Insulin-Like Growth Factor-I and Its Interaction with Gonadotropins, Estradiol, and Fetal Calf Serum on In Vitro Maturation and Parthenogenic Development in Equine Oocytes Biol Reprod, March 1, 2001; 65(3): 899 - 905. [Abstract] [Full Text] [PDF]

				D. Monniaux, P. Monget, C. Pisselet, J. Fontaine, and J.M. Elsen Consequences of the Presence of the Booroola F Gene on the Intraovarian Insulin-Like Growth Factor System and Terminal Follicular Maturation in Merinos d'Arles Ewes Biol Reprod, October 1, 2000; 63(4): 1205 - 1213. [Abstract] [Full Text]

				M. T. Spicer, B. J. Stoecker, T. Chen, and L. J. Spicer Maternal and Fetal Insulin-Like Growth Factor System and Embryonic Survival During Pregnancy in Rats: Interaction between Dietary Chromium and Diabetes J. Nutr., December 1, 1998; 128(12): 2341 - 2347. [Abstract] [Full Text]