Importance of the<i>icmN</i>gene in the growth of<i>Legionella pneumophila</i>in amoebic cells at low temperature
Bibliographic record
Abstract
Legionella pneumophila grows in amoebae and has achieved the ability to grow at various temperatures, although the mechanisms controlling this ability remain poorly understood. The Icm/Dot type IVB secretion system is composed of more than 25 proteins and is known to be essential for intracellular growth. The role of the icmN gene in intracellular multiplication and the effects of culture temperatures on it are not precisely understood. We conducted our investigation using an icmN mutant made by gene replacement mutagenesis. Intracellular growth of the mutant was impaired both in mammalian macrophages and amoeba at 37 °C. In particular, intracellular growth in amoebae was completely impaired at 25 °C. It was found that genes from icmN to icmC formed an operon, i.e., icmN, -M, -L, -E, -G, -C,, and the promoter activity of the icmN operon was stronger at 25 than at 37 °C. It was suggested that icmM and its downstream genes had a secondary promoter that enables icmN mutant grow in amoebae at lower temperatures and macrophages at 37 °C. These results show that the icmN promoter has a low temperature inducible nature, and gene products of the icmN operon require high expression for bacterial proliferation at low temperatures within amoeba.
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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 | 0.000 |
| 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 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".