Acetylation of histone H4 in complex structural transitions of spermiogenic chromatin
Bibliographic record
Abstract
In spermiogenic nuclei of the cephalopod mollusc Sepia officinalis histones are replaced by a precursor-protamine molecule, which is later converted into protamine. Simultaneously, spermiogenic chromatin undergoes a complex structural change. Somatic-like chromatin belonging to the earliest spermatid is progressively reorganized into: (a) granules of 20 nm diameter, (b) fibres of 30-35 nm, and (c) fibres of 40-50 nm. In the final phases of spermiogenesis these fibres of 40-50 nm join to form larger structures of condensed chromatin, and lastly, the uniformly packed chromatin in the sperm nucleus. Using specific antibodies for mono- and hyperacetylated forms of histone H4, in this work we show that the first structural remodelling of chromatin (from somatic-like organization into 20 nm granules) is given concomitantly with a massive mono-acetylation of H4 (acetylation in lysine 12), whereas the structural remodelling from 30-35 to 40-50 nm fibres is produced simultaneously with hyperacetylation of H4 and the nuclear removal of histones.
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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".