Glucocorticoid receptor activation following elevated oocyte cortisol content is associated with zygote activation, early embryo cell division, and IGF system gene responses in rainbow trout
Bibliographic record
Abstract
Increased in ovo cortisol content of rainbow trout oocytes from ~3·5 to ~5·0 ng.oocyte(-1) before fertilization enhances the growth of embryos and juveniles and changes the long-term expression pattern of IGF-related genes. This study used embryos reared from oocytes enriched with cortisol and the glucocorticoid receptor (GR) antagonist, RU486, to determine whether the growth-promoting actions of cortisol involve GR protein activation and modulation of gr expression. Whole-mount in situ immunohistofluorescence studies of zygotes showed that enhanced oocyte cortisol increased the immunofluorescent GR signal and activated the relocation of GR from a general distribution throughout the cytoplasm to an accumulation in the peri-nuclear cytoplasm. In ovo cortisol treatment increased the number of embryonic cells within 48-h post-fertilization, and RU486 partially suppressed this cortisol stimulation of cell duplication. In addition, there was complex interplay between the expression of gr and igf system-related genes spatiotemporally in the different treatment groups, suggesting a role for GR in the regulation of the expression of development. Taken together, these findings indicate an essential role for GR in the regulation of epigenomic events in very early embryos that promoted the long-term growth effects of the embryos and juvenile fish. Moreover, the pretreatment of the oocyte with RU486 had a significant suppressive effect on the maternal mRNA transcript number of gr and igf system-related genes in oocytes and very early stage embryos, suggesting an action of antagonist on the stability of the maternal transcriptome.
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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 | 0.001 |
| 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".