Patterns of Expression of Messenger RNAs Encoding GDF9, BMP15, TGFBR1, BMPR1B, and BMPR2 During Follicular Development and Characterization of Ovarian Follicular Populations in Ewes Carrying the Woodlands FecX2W Mutation

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 t...