|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Wallaceville Animal Research Centre,3 AgResearch, Upper Hutt 5140, New Zealand
Molecular Biology Unit,4 AgResearch, Dunedin 9054, New Zealand
Invermay Agricultural Centre,5 AgResearch, Mosgiel 9053, New Zealand
School of Biological Sciences,6 Victoria University of Wellington, Wellington 6140, New Zealand
ABSTRACT
Woodlands sheep have a putative genetic mutation (FecX2W) that increases ovulation rate. At present, the identity of FecX2W is unknown. The trait does not appear to be due to the previously described mutations in bone morphogenetic protein 15 (BMP15), growth differentiation factor 9 (GDF9), or bone morphogenetic protein receptor type 1B (BMPR1B) that affect ovulation rate in sheep. Potentially, FecX2W could be an unidentified genetic mutation in BMP15 or in the closely related GDF9, which interacts with BMP15 to control ovarian function. Alternatively, FecX2W may affect ovulation rate by changing the expression patterns in the molecular pathways activated by genes known to regulate ovulation rate. The objectives of these experiments were to sequence the complete coding region of the BMP15 and GDF9 genes, determine the patterns of expression of mRNAs encoding GDF9, BMP15, TGFBR1, BMPR1B, and BMPR2 during follicular development, and characterize the follicular populations in ewes heterozygous for the Woodlands mutation and their wild-type contemporaries. No differences in the coding sequences of BMP15 or GDF9 genes were identified that were associated with enhanced ovulation rate. The expression patterns of GDF9 and BMPR2 mRNAs were not different between genotypes. However, expression of BMP15 mRNA was less in oocytes of FecX2W ewes in large preantral and antral follicles. Expression of ALK5 mRNA was significantly higher in the oocytes of FecX2W ewes, whereas expression of BMPR1B was decreased in both oocytes and granulosa cells of FecX2W ewes. FecX2W ewes also had increased numbers of antral follicles <1 mm in diameter. These follicles were smaller in average diameter, with the oocytes also being of a smaller mean diameter. Given that a mutation in BMP15 or BMPR1B results in increased ovulation rates in sheep, the differences in expression levels of BMP15 and BMPR1B may play a role in the increase in ovulation rate observed in Woodlands ewes with the FecX2W mutation.
follicle, gene regulation, ovary, transforming growth factor beta superfamily
1Supported by the Marsden Fund, administered by the Royal Society of New Zealand and the Foundation for Research Science and Technology, New Zealand. E.S.F. was supported by an Enterprise Scholarship.
Correspondence: 2Jenny Juengel, AgResearch, Wallaceville Animal Research Centre, Ward St., Upper Hutt 5140, New Zealand. FAX: 64 4 529 0380; e-mail: jenny.juengel{at}agresearch.co.nz
This article has been cited by other articles:
![]() |
F. Paradis, S. Novak, G. K Murdoch, M. K Dyck, W. T Dixon, and G. R Foxcroft Temporal regulation of BMP2, BMP6, BMP15, GDF9, BMPR1A, BMPR1B, BMPR2 and TGFBR1 mRNA expression in the oocyte, granulosa and theca cells of developing preovulatory follicles in the pig Reproduction, July 1, 2009; 138(1): 115 - 129. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Kanakkaparambil, R. Singh, D. Li, R. Webb, and K. D. Sinclair B-Vitamin and Homocysteine Status Determines Ovarian Response to Gonadotropin Treatment in Sheep Biol Reprod, April 1, 2009; 80(4): 743 - 752. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Lupton ASAS CENTENNIAL PAPER: Impacts of animal science research on United States sheep production and predictions for the future J Anim Sci, November 1, 2008; 86(11): 3252 - 3274. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |