Disruption of MEF2 activity in cardiomyoblasts inhibits cardiomyogenesis
Bibliographic record
Abstract
Myocyte enhancer factors (MEF2s) bind to muscle-specific promoters and activate transcription. Drosophila Mef2 is essential for Drosophila heart development, however, neither MEF2C nor MEF2B are essential for the early stages of murine cardiomyogenesis. Although Mef2c-null mice were defective in the later stages of heart morphogenesis, differentiation of cardiomyocytes still occurred. Since there are four isoforms of MEF2 factors (MEF2A, MEF2B, MEF2C and MEF2D), the ability of cells to differentiate may have been confounded by genetic redundancy. To eliminate this variable, the effect of a dominant-negative MEF2 mutant (MEF2C/EnR) during cardiomyogenesis was examined in transgenic mice and P19 cells. Targeting the expression of MEF2C/EnR to cardiomyoblasts using an Nkx2-5 enhancer in the P19 system resulted in the loss of both cardiomyocyte development and the expression of GATA4, BMP4, Nkx2-5 and MEF2C. In transiently transgenic mice, MEF2C/EnR expression resulted in embryos that lacked heart structures and exhibited defective differentiation. Our results show that MEF2C, or genes containing MEF2 DNA-binding sites, is required for the efficient differentiation of cardiomyoblasts into cardiomyocytes, suggesting conservation in the role of MEF2 from Drosophila to mammals.
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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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".