Brefeldin A Inhibits Circadian Remodeling of Chloroplast Structure in the Dinoflagellate <i>Gonyaulax</i>
Bibliographic record
Abstract
Circadian increases in the rate of carbon fixation in the dinoflagellate Gonyaulax are correlated with extensive plastid remodeling. One marker for this remodeling is mobilization of ribulose bisphosphate carboxylase/oxygenase (Rubisco) from the plastid periphery to plastid regions nearer the cell center called pyrenoids. Nuclear-encoded proteins such as Rubisco transit through the Golgi in dinoflagellates; hence, we blocked protein import into the plastids using Brefeldin A (BFA) to explore the mechanism for plastid remodeling. We find that pyrenoid formation normally occurs concurrently with increased Rubisco synthesis rates in vivo, and when BFA is given prior to the onset of Rubisco synthesis, pyrenoid formation is partially or completely inhibited by 0.1 or 0.3 microg/mL BFA, respectively. Rubisco synthesis itself is not affected, and BFA-treated cells accumulate Rubisco in novel structures we term BFA bodies. Interestingly, when given just after the onset of Rubisco synthesis, BFA delays but does not block Rubisco mobilization, suggesting that a timing signal for plastid remodeling is delivered to the organelles at the same time as newly synthesized Rubisco. BFA also inhibits the circadian increases in carbon fixation rates, supporting the hypothesis that the biochemical basis for this circadian rhythm may be Rubisco distribution within the plastid.
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) | 0.000 | 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) | 0.001 | 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".