Mechanisms of calcium sequestration by isolated Malpighian tubules of the house cricket <i>Acheta domesticus</i>
Bibliographic record
Abstract
Abstract Hemolymph calcium homeostasis in insects is achieved by the Malpighian tubules, primarily by sequestering excess Ca 2+ within internal calcium stores (Ca‐rich granules) most often located within type I (principal) tubule cells. Using both the scanning ion‐selective electrode technique and the Ramsay secretion assay this study provides the first measurements of basolateral and transepithelial Ca 2+ fluxes across the Malpighian tubules of an Orthopteran insect, the house cricket Acheta domesticus . Ca 2+ transport was specific to midtubule segments, where 97% of the Ca 2+ entering the tubule is sequestered within intracellular calcium stores and the remaining 3% is secreted into the lumen. Antagonists of voltage‐gated (L‐type) calcium channels decreased Ca 2+ influx ≥fivefold in adenosine 3′,5′‐cyclic monophosphate (cAMP)‐stimulated tubules, suggesting basolateral Ca 2+ influx is facilitated by voltage‐gated Ca 2+ channels. Increasing fluid secretion through manipulation of intracellular levels of cAMP or Ca 2+ had opposite effects on tubule Ca 2+ transport. The adenylyl cyclase‐cAMP‐PKA pathway promotes Ca 2+ sequestration whereas both 5‐hydroxytryptamine and thapsigargin inhibited sequestration. Our results suggest that the midtubules of Acheta domesticus are dynamic calcium stores, which maintain hemolymph calcium concentration by manipulating rates of Ca 2+ sequestration through stimulatory (cAMP) and inhibitory (Ca 2+ ) regulatory pathways.
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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 | 0.003 |
| 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".