Development of a short-term reproductive endocrine bioassay using steroid hormone and vitellogenin end points in the estuarine mummichog (<i>Fundulus heteroclitus</i>)
Bibliographic record
Abstract
We have developed a short-term gonadal recrudescence test with the estuarine mummichog (Fundulus heteroclitus) and determined endocrine end points sensitive to a strong estrogen agonist (ethynylestradiol; EE2) and an antiestrogen (ZM 189,154; ZM) at concentrations of 0 to 1,000 ng/L in three separate experiments. A protocol was developed to ensure a year-round supply of recrudescing fish. A protocol for determining steroid production (testosterone and 11-ketotestosterone [11-KT] in incubated testes tissue and testosterone and 17-estradiol [E2] in incubated prematurational follicles) was optimized. Recrudescing fish (males, gonadosomatic index = 2%; females = 10%) were exposed to graded doses of EE2 or ZM for 7 to 15 d using a static daily-renewal protocol. At high EE2 (>250 ng/L), the effect on males was depression of androgen steroidogenesis and plasma steroid levels. In females, high EE2 depressed gonadal production and circulating E2 levels; however, EE2 concentrations <100 ng/L caused increased gonadal production and plasma E2. Low ZM (<100 ng/L) had little effect on male and female fish, while higher concentrations (>250 ng/L) increased E2 and 11-KT production while decreasing plasma 11-KT and E2 (1,000 ng/L only). Male and female plasma vitellogenin responded in a concentration-dependent fashion to EE2 with no effect by ZM. The low observable effect concentrations for the endocrine parameters were 1 ng/L for EE2 and 250 ng/L for ZM. The bioassay and results encompassing the environmentally relevant exposure range (1-100 ng/L) will be useful for assessing effects of endocrine-active contaminants in estuarine environments.
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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 | 0.001 |
| 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 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".