Effect of the Luteinizing Hormone Surge on the RNA Expression of Granulosa Cells During Final Maturation of the Bovine Follicle.
Bibliographic record
Abstract
During the mono-ovulatory estrus cycle, FSH and LH play an important role for growth, selection and dominance of the preovulatory follicle. The dominance of a follicle is characterized by the acquisition of luteinizing hormone (LH) receptors on granulosa cells (GC) and the transfer of its dependency for follicle-stimulating hormone (FSH) to LH. The LH surge induces profound changes in GC functions, which must be modified in a precise chronological order. These changes ultimately lead to the release of the matured oocyte during the follicular rupture at ovulation. On a transcriptional level, the gene expression cascades induced by this hormone, which lead to ovulation, are complex and still poorly understood. The objective of this study is to determine how the gene expression profile of GCs is modulated by the LH surge. The estrus of thirty animals were synchronized, they were then stimulated with FSH and finally the LH surge was induced by gonadotropin releasing hormone injection on day 14.5. Three different groups of GCs were collected by ovariectomy; (1) 2 h before the induction of the LH surge, (2) 6 h and (3) 22 h after the LH surge. The RNA of the different GC groups was extracted, amplified, labeled and hybridized on a microarray slide. A bovine oligonucleotide-spotted microarray (24K) was used to profile all known protein-encoding transcripts. The results obtained from the microarray data analysis showed that most transcripts were present in every type of GC studied. However, candidates were found to be preferentially expressed in only one of the GC states. Moreover, an unsupervised hierarchal clustering indicates that the overall GC expression of 2 h pre-LH and 6 h post LH correlate more closely than with the 22 h post LH, which is consistent with the endogenous ovarian physiological functions as GCs undergo extreme changes in order to achieve their luteal role. To understand the effect of LH on granulosa cell gene expression, transcripts fluctuating at the 6h post-LH stage were analyzed using pathway analysis software. Globally, the representation at 6 h post LH indicates that the follicles expresses genes involved in cell-to-cell interactions (like PTP4A3, THBS1, PPAP2B), in the inflammatory response (like B4GALT1, THBS1, TRAF3IP2) and in lipid metabolism modifications (like ACSL3, CYP51A1, FADS2). In conclusion, our goal is to put these follicular events in the context of oocyte developmental competence as it is gradually acquired during follicular growth and maximized during the last stages of follicular maturation. (poster)
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".