| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Regular Article |
a Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison, Wisconsin 53706
b The Eutherian Foundation, Cross Plains, Wisconsin 53528
Follicle diameter deviation during follicular waves in cattle begins with a reduction in growth rates of developing subordinate follicles, in contrast to the maintenance of a constant growth rate by a developing dominant follicle. In experiment 1, the temporal changes encompassing deviation in concentrations of follicular fluid factors relative to one another in the three largest follicles (F1, F2, and F3) were studied. Follicular fluid samples were collected when F1 reached diameter ranges of 7.0–7.9, 8.0–8.9, 9.0–9.9, and 10.0–10.9 mm (n = 12 per range). The first increase (P < 0.05) in the difference between F1 and F2 for estradiol occurred at the 8.0- to 8.9-mm range, which was one range earlier than for diameter (P < 0.05). Free insulin-like growth factor (IGF)-1 concentrations in F1 were similar among diameter ranges, but concentrations in F1 were higher (P < 0.05) than in F2 for each range except 7.0–7.9 mm. Concentrations of free IGF-1 in F2 decreased (P < 0.05). No significant differences were detected in concentrations of progesterone, androstenedione, total inhibin, and inhibin-A. Averaged over follicles, inhibin-B decreased (P < 0.05) between the 8.0- to 8.9- and 10.0- to 10.9-mm ranges, and activin-A increased (P < 0.05) between the 7.0- to 7.9- and 9.0- to 9.9-mm ranges. However, no differences were found among follicles. In experiment 2, changes associated with the development of dominance by F2 were studied using ablation of F1 at the beginning of expected deviation (F1, 8.5 mm; Hour 0) as the reference point. Follicular fluid factors were compared at Hour 12 between F2 of a control group (F1 intact; n = 10) and an ablated group (F1 ablated; n = 10). Diameter (P < 0.02), estradiol (P < 0.001), free IGF-1 (P < 0.002), and progesterone (P < 0.003) were greater and IGF-binding protein-2 was lower (P < 0.01) in F2 of the ablated group at Hour 12. No differences were detected in concentrations of androstenedione, total inhibin, and inhibin-A. The results of the two experiments indicated, on a temporal basis, that intrafollicular changes in estradiol and the IGF system, but not in the inhibin/activin system, could account for a reported greater FSH responsiveness by the future dominant follicle than by the future subordinate follicles by the beginning of diameter deviation in cattle.
1 Supported by the University of Wisconsin, Madison, and by Equiservices Publishing and The Eutherian Foundation, Cross Plains, Wisconsin.
2 Correspondence: O.J. Ginther, Department of Animal Health and Biomedical Sciences, 1656 Linden Drive, University of Wisconsin-Madison, Madison, WI 53706. FAX: 608 262 7420; ojg{at}ahabs.wisc.edu
This article has been cited by other articles:
|
|
 |
|
  M Mihm, P J Baker, L M Fleming, A M Monteiro, and P J O'Shaughnessy Differentiation of the bovine dominant follicle from the cohort upregulates mRNA expression for new tissue development genes Reproduction, February 1, 2008; 135(2): 253 - 265. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. T. Grazul-Bilska, C. Navanukraw, M. L. Johnson, K. A. Vonnahme, S. P. Ford, L. P. Reynolds, and D. A. Redmer Vascularity and expression of angiogenic factors in bovine dominant follicles of the first follicular wave J Anim Sci, August 1, 2007; 85(8): 1914 - 1922. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M A Beg and O J Ginther Follicle selection in cattle and horses: role of intrafollicular factors. Reproduction, September 1, 2006; 132(3): 365 - 377. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O J Ginther, E L Gastal, M O Gastal, and M A Beg In vivo effects of pregnancy-associated plasma protein-A, activin-A and vascular endothelial growth factor on other follicular-fluid factors during follicle deviation in mares Reproduction, April 1, 2005; 129(4): 489 - 496. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T.J. Acosta, E.L. Gastal, M.O. Gastal, M.A. Beg, and O.J. Ginther Differential Blood Flow Changes Between the Future Dominant and Subordinate Follicles Precede Diameter Changes During Follicle Selection in Mares Biol Reprod, August 1, 2004; 71(2): 502 - 507. [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]
|
|
|
|
|
|
O.J. Ginther, D.R. Bergfelt, M.A. Beg, C. Meira, and K. Kot In Vivo Effects of an Intrafollicular Injection of Insulin-Like Growth Factor 1 on the Mechanism of Follicle Deviation in Heifers and Mares Biol Reprod, January 1, 2004; 70(1): 99 - 105. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Sisco, L. J. Hagemann, A. N. Shelling, and P. L. Pfeffer Isolation of Genes Differentially Expressed in Dominant and Subordinate Bovine Follicles Endocrinology, September 1, 2003; 144(9): 3904 - 3913. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. M. Rivera and J. E. Fortune Proteolysis of Insulin-Like Growth Factor Binding Proteins -4 and -5 in Bovine Follicular Fluid: Implications for Ovarian Follicular Selection and Dominance Endocrinology, July 1, 2003; 144(7): 2977 - 2987. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K.I. Parker, D.M. Robertson, N.P. Groome, and K.L. Macmillan Plasma Concentrations of Inhibin A and Follicle-Stimulating Hormone Differ Between Cows with Two or Three Waves of Ovarian Follicular Development in a Single Estrous Cycle Biol Reprod, March 1, 2003; 68(3): 822 - 828. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O.J. Ginther, M.A. Beg, K. Kot, C. Meira, and D.R. Bergfelt Associated and Independent Comparisons Between the Two Largest Follicles Preceding Follicle Deviation in Cattle Biol Reprod, February 1, 2003; 68(2): 524 - 529. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O.J. Ginther, C. Meira, M.A. Beg, and D.R. Bergfelt Follicle and Endocrine Dynamics During Experimental Follicle Deviation in Mares Biol Reprod, September 1, 2002; 67(3): 862 - 867. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O.J. Ginther, M.A. Beg, D.R. Bergfelt, and K. Kot Activin A, Estradiol, and Free Insulin-Like Growth Factor I in Follicular Fluid Preceding the Experimental Assumption of Follicle Dominance in Cattle Biol Reprod, July 1, 2002; 67(1): 14 - 19. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
