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.
This study aimed to describe the abundance and localization of BMP2, BMP6, BMP15, GDF9, BMPR1A, BMPR1B, BMPR2 and TGFBR1 mRNA during pig preovulatory follicular development and to evaluate their implication in improving follicular maturity in the preovulatory period preceding the second versus first post-weaning oestrus. Oocytes, granulosa (GC) and theca cells (TC) were recovered from antral follicles of primiparous sows at day 1, 2 and 4 after weaning and at day 14, 16 and 20 of their subsequent oestrous cycle. Real-time PCR analysis revealed that with the exception of BMP6 mRNA, which was absent in GC, all genes were expressed in every cell type. Although BMP6, BMP15 and GDF9 mRNA were most abundant in the oocyte, their expression remained relatively constant during follicular development. By contrast, receptor BMPR1B and TGFBR1 expressions in the GC and TC were temporally regulated. BMPR1B mRNA abundance was positively correlated with plasma oestradiol (E2) suggesting that its regulation by oestrogen may be implicated in normal folliculogenesis. Interestingly, the increase in BMPR1B mRNA and protein abundance during the periovulatory period in GC and TC suggests a role for bone morphogenetic protein (BMP) 15 in the ovulatory process. Finally, expression of these ligands and receptors was not associated with potential differences in follicle maturity observed during the second versus first post-weaning preovulatory follicular wave. In conclusion, our results clearly demonstrate the presence of a complex signalling system within the pig follicle involving the transforming growth factor-beta superfamily and their receptors, and provide evidence to support a role for BMP15 and BMPR1B during ovulation.
Paradis
Francois
F
Swine Reproduction-Development Program, Department of Agricultural, Food and Nutritional Science, 4-10 Agriculture-Forestry Centre, University of Alberta, Edmonton, Alberta T6G 2P5, Canada. fparadis@ualberta.ca
Novak
Susan
S
Murdoch
Gordon K
GK
Dyck
Michael K
MK
Dixon
Walter T
WT
Foxcroft
George R
GR
D000818:Animals; D015153:Blotting, Western; D055430:Bone Morphogenetic Protein 15 / Q000235:genetics* / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics* / Q000378:metabolism; D055418:Bone Morphogenetic Protein 6 / Q000235:genetics* / Q000378:metabolism; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000235:genetics* / Q000378:metabolism; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics* / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006107:Granulosa Cells / Q000378:metabolism*; D055429:Growth Differentiation Factor 9 / Q000235:genetics* / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D011863:Radioimmunoassay; D060888:Real-Time Polymerase Chain Reaction; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism; D046468:Sexual Development; D015398:Signal Transduction / Q000235:genetics; D013552:Swine / Q000235:genetics* / Q000378:metabolism; D013799:Theca Cells / Q000378:metabolism*; D013997:Time Factors
D055430:Bone Morphogenetic Protein 15; D055396:Bone Morphogenetic Protein 2; D055418:Bone Morphogenetic Protein 6; D055429:Growth Differentiation Factor 9; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D004958:Estradiol; D017346:Protein Serine-Threonine Kinases; D052005:Bone Morphogenetic Protein Receptors, Type I; D052006:Bone Morphogenetic Protein Receptors, Type II; D000077293:Receptor, Transforming Growth Factor-beta Type I