Regulation of Fibroblast Growth Factor 22 and Fibroblast Growth Factor Receptor 1b in Bovine Antral Follicles.
Bibliographic record
Abstract
Fibroblast growth factors (FGF) are grouped into several FGF families according to structural and functional properties, and play a number of different physiological roles including regulation of folliculogenesis. Two of the three members of the FGF7 family (FGF7, 10 and 22) were previously assessed in the follicle; FGF7 and 10 were principally located in theca cells (TC) and inhibited estradiol production from granulosa cells (GC). FGF10 expression was lowest in atretic follicles and was negatively correlated with estradiol secretion in transitional and healthy follicles, whereas FGF7 expression appears not to be developmentally regulated in the follicle. This family acts through receptors FGFR2B, which is principally expressed by GC of healthy estrogenic follicles, and FGFR1B. The first aim of this study was to determine the spatial and temporal patterns of FGF22 and FGFR1B mRNA expression in bovine antral follicles. As FGF22 and FGFR1B expression was altered by follicle status, we then used culture studies to assess regulation of gene expression by gonadotropins and IGF1 in GC and TC. Antral follicles greater than 5mm in diameter were dissected from abattoir ovaries, GC and TC separated and total RNA extracted. Estradiol (E) and progesterone (P) concentrations of the follicular fluid were measured by RIA and follicles were grouped according to E:P ratios of <0.01 (atretic, n=15), 0.01-1 (transitional, n=13) and >1 (healthy, n=15). Cumulus-oocyte complexes (COCs) were aspirated from morphologically healthy follicles grouped by size (1-3, 3.1 to 6, 6.1 to 8 and >8mm; n=4); oocytes and cumulus cells were separated and total RNA extracted from pools of each cell type obtained from 20 COCs. Effects of FSH and IGF1 on GC gene expression and effects of LH on TC gene expression were tested; GC and TC from small follicles (2-5 mm) were cultured in serum-free medium with either FSH (0, 0.05, 0.1, 0.5 or 1 ng/ml), IGF1 analog (0, 5, 10, 50 or 100ng/ml) or LH (0, 1, 10, or 100 ng/ml). Expression of FGF22 and FGFR1B mRNA was assessed by real time RT-PCR using bovine-specific primers and GAPDH, PP1A and H2AFZ as endogenous controls. Relative expression was determined by the Pfaffl equation. FGF22 and FGFR1B mRNA was detected in TC, GC and cumulus cells but not in oocytes. Expression of both target genes was higher in atretic follicles compared with transitional and healthy follicles (P< 0.01), and did not vary with follicle size in cumulus cells. In GC, IGF1 inhibited FGF22 and FGFR1B expression at 5 and 10ng/ml, respectively (P<0.05), but FSH did not alter mRNA abundance. In TC, LH increased FGFR1B expression at 100 ng/ml (P=0.01), but did not change FGF22 expression. In conclusion, expression of both FGF22 ligand and receptor is increased in atretic follicles and is inhibited by IGF1 in GC from healthy follicles. Unlike the other members of the FGF7 family, FGF22 appears to play a specific role in the control of follicle atresia through activation of FGFR1B. Supported by FAPESP. (poster)
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".