Interplay mechanisms between progesterone and endocannabinoid receptors in regulating bull sperm capacitation and acrosome reaction
Bibliographic record
Abstract
After ejaculation, sperm show a limited capacity for transcription and translation. In the oviduct, most of the signalling in sperm is nongenomic and is mediated through membrane receptors. Studies have shown that the cation channel of sperm (CatSper), cAMP, cGMP, protein kinases, and tyrosine phosphorylation are involved in the nongenomic signalling of progesterone (P4) in sperm. However, it is not known whether there is an interplay between P4 and cannabinoid receptors 1 and 2 (CB1 and CB2), transient receptor potential vanilloid 1 (TRPV1), CatSper channels, cAMP, inositol trisphosphate receptor (IP3R), and mitogen-activated protein kinase (MAPK); these potential regulators are involved in the regulation of capacitation and the acrosome reaction. In the present study, selective blockers of CB1, CB2, TRPV1, CatSper channels, cAMP, protein kinase A (PKA), IP3R, and MAPK were used to identify their involvement in P4-mediated bull sperm capacitation and the acrosome reaction. Selective blocking of any one of the molecules caused a significant reduction in P4 signalling (p < 0.05). Interestingly, blocking these molecules in combination followed by treatment with P4 resulted in the complete absence of capacitation and the acrosome reaction. Blocking a single receptor was not able to eliminate the P4-induced capacitation and the acrosome reaction. In addition to the CB1 and CB2 receptors, there may be other signalling pathways that mediate P4 signalling. In conclusion, P4 signalling exhibited interplay with the cannabinoid receptors. The regulation of sperm capacitation and the acrosome reaction also involved cAMP, PKA, l-type and T-type calcium channels, TRPV1, inositol trisphosphate, and MAPK.
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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 | 0.000 |
| 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) | 0.000 | 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".