MLL1 is required for PAX7 expression and satellite cell self-renewal in mice
Bibliographic record
Abstract
PAX7 is a paired-homeobox transcription factor that specifies the myogenic identity of muscle stem cells and acts as a nodal factor by stimulating proliferation while inhibiting differentiation. We previously found that PAX7 recruits the H3K4 methyltransferases MLL1/2 to epigenetically activate target genes. Here we report that in the absence of Mll1, myoblasts exhibit reduced H3K4me3 at both Pax7 and Myf5 promoters and reduced Pax7 and Myf5 expression. Mll1-deficient myoblasts fail to proliferate but retain their differentiation potential, while deletion of Mll2 had no discernable effect. Re-expression of PAX7 in committed Mll1 cKO myoblasts restored H3K4me3 enrichment at the Myf5 promoter and Myf5 expression. Deletion of Mll1 in satellite cells reduced satellite cell proliferation and self-renewal, and significantly impaired skeletal muscle regeneration. Pax7 expression was unaffected in quiescent satellite cells but was markedly downregulated following satellite cell activation. Therefore, MLL1 is required for PAX7 expression and satellite cell function in vivo. Furthermore, PAX7, but not MLL1, is required for Myf5 transcriptional activation in committed myoblasts.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.003 |
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".