Ploidy reduction in <i>Saccharomyces cerevisiae</i>
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Large-scale transitions in genome size from tetraploid to diploid were observed during a previous 1800-generation evolution experiment in Saccharomyces cerevisiae. Whether the transitions occurred via a one-step process (tetraploid to diploid) or through multiple steps (through ploidy intermediates) remained unclear. To provide insight into the mechanism involved, we investigated whether triploid-sized cells sampled from the previous experiment could also undergo ploidy loss. A batch culture experiment was conducted for approximately 200 generations, starting from four triploid-sized colonies and one contemporaneous tetraploid-sized colony. Ploidy reduction towards diploidy was observed in both triploid and tetraploid lines. Comparative genomic hybridization indicated the presence of aneuploidy in both the founder and the evolved colonies. The specific aneuploidies involved suggest that chromosome loss was not haphazard but that nearly full sets of chromosomes were lost at once, with some additional chromosome mis-segregation events. These results suggest the existence of a mitotic mechanism allowing the elimination of an entire set of chromosomes in S. cerevisiae, thereby reducing the ploidy level.
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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 | 0.001 | 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) | 0.000 | 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 it