Manganese inhibits spontaneous nuclear maturation in bovine cumulus-enclosed oocytes
Bibliographic record
Abstract
The objective of this work was to examine the effects of manganese concentration on nuclear maturation of bovine cumulus-enclosed (CEO) and denuded oocytes cultured for 7 h or 22 h. Following culture, oocytes were then fixed and stained for assessment of nuclear maturation stage. The addition of MnCl2 significantly suppressed nuclear maturation after 7h of culture (15, 69, 84 and 70% of oocytes were still at the germinal vesicle stage after culture with 0, 50 μM, 0.5 mM and 5mM MnCl2, respectively; P < 0.001). However, MnCl2 was without significant effect on denuded oocytes cultured for 7 h. When CEO and denuded oocytes were cultured with manganese for 22 h, the percentages of mature oocytes were reduced (96 , 20, 15, 3% and 80, 39, 53 and 16% for CEO and denuded oocytes cultured with 0, 50 μM, 0.5 mM and 5 mM MnCl2, respectively; P < 0.0005). The inhibitory effect of 50 μM MnCl2 was transient and reversible because it did not maintain oocytes in meiotic arrest after 22 h of culture. In addition, 72% of the CEO cultured with 50 μM MnCl2 for 7 h and subsequently cultured without manganese for 18 h were mature. The concentration of manganese (6 ± 1 μM) in follicular fluid (as determined by atomic absorption spectrophotometry) was below inhibitory concentrations. In conclusion, manganese inhibited germinal vesicle breakdown in bovine CEO; however, only the effect of the lowest concentration tested (50 μM) was reversible. Key words: Bovine, oocyte, meiosis, manganese, follicular fluid
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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".