Transition of nuclear proteins and chromatin structure in spermiogenesis of <i>Sepia officinalis</i>
Bibliographic record
Abstract
During spermiogenesis of Sepia officinalis histones are directly substituted by a molecule of precursor protamine, which is later transformed into the protamine through a deletion of the amino terminal end. In the present work, it is shown that the pattern of spermiogenic chromatin condensation consists of a phase of "patterning" and a phase of "condensation." In the phase of patterning, three structural remodelings are produced in the chromatin structure: [somatic-like chromatin --> 18 nm granules --> 25 nm fibers --> 44 nm fibers]. The first remodeling of the chromatin into granules of 18 nm takes place without the entrance of specific proteins in the spermiogenic nuclei. The second remodeling [granules of 18 nm --> fibers of 25 nm] is due to the entrance of the precursor protamine and its interaction with the DNA-histone complex. The third remodeling [fibers of 25 nm --> fibers of 44 nm] occurs simultaneously with the disappearance of histones from the chromatin. In the phase of condensation, the fibers of 44 nm coalesce among themselves to form progressively larger aggregates of chromatin. In this phase there are no substantial variations in the nuclear proteins, so that the condensation of the chromatin must respond to posttranscriptional changes of the precursor protamine (dephosphorylation, deletion of the amino-terminal end).
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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".