Neither Maternal nor Zygotic <i>med-1/med-2</i> Genes Play a Major Role in Specifying the <i>Caenorhabditis elegans</i> Endoderm
Bibliographic record
Abstract
The med-1 and med-2 genes encode small, highly similar proteins related to GATA-type transcription factors and have been proposed as necessary for specification of both the mesoderm and the endoderm of Caenorhabditis elegans. However, we have previously presented evidence that neither maternal nor zygotic expression of the med-1/2 genes is necessary to specify the C. elegans endoderm. Contradicting our conclusions, a recent report presented evidence, based on presumed transgene-induced cosuppression, that the med-1/2 genes do indeed show an endoderm-specifying maternal effect. In this article, we reinvestigate med-2(-); med-1(-) embryos using a med-2- specific null allele instead of the chromosomal deficiences used previously and confirm our previous results: the large majority (approximately 84%) of med-2(-); med-1(-) embryos express gut granules. We also reinvestigate the possibility of a maternal med-1/2 effect by direct injection of med dsRNA into sensitized (med-deficient) hermaphrodites using the standard protocol known to be effective in ablating maternal transcripts, but again find no evidence for any significant maternal med-1/2 effect. We do, however, show that expression of gut granules in med-1/2-deficient embryos is exquisitely sensitive to RNAi against the vacuolar ATPase-encoding unc-32 gene [present on the same multicopy med-1(+)-containing transgenic balancer used in support of the maternal med-1/2 effect]. We thus suggest that the experimental evidence for a maternal med-1/2 effect should be reexamined and may instead reflect cosuppression caused by multiple transgenic unc-32 sequences, not med sequences.
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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 | 0.000 |
| 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 | 0.001 | 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".