Calcium-binding proteins and calcium-release channels in human maturing oocytes, pronuclear zygotes and early preimplantation embryos
Bibliographic record
Abstract
BACKGROUND: The study aim was to investigate the presence and localization of Ca2+-binding proteins and Ca2+-release receptor channels in human maturing oocytes, pronuclear zygotes and preimplantation embryos. METHODS: Immunocytochemical analysis, using specific antibodies against the proteins being studied, followed with confocal laser microscopy, was performed on human oocytes and embryos. RESULTS: Calreticulin and calsequestrin (the two major calcium storage proteins of somatic cells), two types of calcium release receptors, the inositol trisphosphate and ryanodine receptors (InsP(3)R-2, RyRs-1,2,3), and the molecular chaperone, calnexin, were identified in all investigated cell types. Calreticulin was predominant in the cell cortex and in the nuclear envelope, while calsequestrin was distributed throughout the entire cytoplasm. Generally, localization of the InsP(3)R-2 and RyRs was similar to that of calreticulin and calsequestrin respectively. Both types of receptor were enriched in the subplasmalemmal region of meiotic oocytes. In addition, the InsP(3)R was detected in the nuclear structures of oocytes and blastomeres. Calnexin distribution overlapped with that of calreticulin but appeared to be present in distinct subcompartments. CONCLUSIONS: Human oocytes and embryos express the calcium sequestration and release proteins in highly organized and developmentally regulated patterns. Fine-tuning of these proteins may play a crucial role in regulation of Ca2+ transience during oocyte maturation, fertilization and early embryo development.
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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".