Modulation of bovine sperm signalling pathways: correlation between intracellular parameters and sperm capacitation and acrosome exocytosis
Bibliographic record
Abstract
In the present study, the viability, intracellular pH (pHi), cAMP ([cAMP]i), calcium concentration and protein phosphotyrosine content were evaluated in relation to the acrosomal and capacitation status of freshly ejaculated bull spermatozoa. These parameters were evaluated before and after incubation with the capacitation inducer heparin, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), the phosphotyrosyl-protein phosphatase inhibitors phenylarsine oxide (PAO) and sodium orthovanadate, and hydrogen peroxide. The results obtained were integrated to address the physiological interactions between the different signalling events affecting sperm capacitation and acrosome reaction. As expected, heparin promoted the expression of the 'B' pattern of chlortetracycline binding, increased pHi, [cAMP]i and the phosphotyrosine content of sperm proteins. The effects of heparin were enhanced by IBMX. Both PAO and sodium orthovanadate stimulated protein phosphotyrosine content and acrosomal exocytosis, although only PAO affected pH, Ca2+ and cAMP levels. Intracellular pH was increased while both Ca2+ and [cAMP]i were decreased. Physiological concentrations of H2O2 increased [cAMP]i and promoted acrosomal exocytosis. A significant positive correlation was found between sperm capacitation, protein phosphotyrosine content and stored Ca2+ concentration, whereas the acrosome reaction was correlated with pHi and Ca2+ concentration. This study presents the first global analysis of the major elements individually described during sperm capacitation and acrosome reaction signalling pathways, supported by statistical correlations.
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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".