The influence of control group reproduction on the statistical power of the Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT)

Flynn, Kevin; Swintek, Joe; Johnson, Rodney D.

doi:10.1016/j.ecoenv.2016.10.024

Cited by 3 publications

(5 citation statements)

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“…The fecundity data from some of the earlier tests had relatively high variance. With only 6 breeding replicates per treatment, the statistical power for detecting significant changes in fecundity was quite low . Minor modifications of the protocol were implemented to increase the statistical power of the protocol by increasing baseline fecundity and reducing the variance in egg production.…”

Section: Resultsmentioning

confidence: 99%

“…To determine the number of replicates preferred, a power analysis was performed using the reproductive performance of control fish from several of the tests . The fecundity data had several characteristics that complicated the simple straightforward calculations of statistical power.…”

Section: Resultsmentioning

confidence: 99%

“…In reproductive assessments, mean fecundity was lower (22 ± 3 eggs/female/day) at 24 °C than the fecundity observed at 25 ° C (36 ± 3 eggs/female/day). These gains in reproductive performance have large impacts on the statistical power of this endpoint simply by increasing the measureable effect size . Because of this, temperatures lower than 24 °C were deemed unacceptable.…”

Section: Resultsmentioning

confidence: 99%

“…The recommended temperature of 25 °C for the MEOGRT balances the competing objectives of maximizing fecundity while minimizing the chances of XX males induced by temperature. In addition, because the prevalence of this phenomenon is strain dependent, efforts at the USEPA Mid‐Continent Ecology Division to increase fecundity of the medaka culture by crossing separate lineages have serendipitously reduced the occurrence of XX males to levels less than 1%.…”

Section: Resultsmentioning

confidence: 99%

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Summary of the development the US Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT) using data from 9 multigenerational medaka tests

Flynn

Lothenbach

Whiteman

et al. 2017

Enviro Toxic and Chemistry

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In response to various legislative mandates, the US Environmental Protection Agency (USEPA) formed its Endocrine Disruptor Screening Program (EDSP), which in turn, formed the basis of a tiered testing strategy to determine the potential of pesticides, commercial chemicals, and environmental contaminants to disrupt the endocrine system. The first tier of tests is intended to detect the potential for endocrine disruption mediated through estrogen, androgen, or thyroid pathways, whereas the second tier is intended to further characterize the effects on these pathways and to establish a dose-response relationship for adverse effects. One of these tier 2 tests, the Medaka Extended One Generation Reproduction Test (MEOGRT), was developed by the USEPA for the EDSP and, in collaboration with the Japanese Ministry of the Environment, for the Guidelines for the Testing of Chemicals of the Organisation for Economic Co-operation and Development (OECD). The MEOGRT protocol was iteratively modified based on knowledge gained after the successful completion of 9 tests with variations in test protocols. The present study describes both the final MEOGRT protocol that has been published by the USEPA and the OECD, and the iterations that provided valuable insights into nuances of the protocol. The various tests include exposure to 17β-estradiol, 4-t-octylphenol, o,p'- dichlorodiphenyltrichloroethane, 4-chloro-3-methylphenol, tamoxifen, 17β-trenbolone, vinclozolin, and prochloraz. Environ Toxicol Chem 2017;36:3387-3403. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Summary of the development the US Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT) using data from 9 multigenerational medaka tests

Flynn

Lothenbach

Whiteman

et al. 2017

Enviro Toxic and Chemistry

Self Cite

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“…Briefly, F0 generation exposure was initiated to breeding pairs aged 12 wpf (age 12–16 wpf is recommended ) in a 2‐L glass chamber. The MEOGRT protocol adopted a 2:1 experimental design (i.e., 12 and 6 replicate breeding pairs per control and the NP exposure group were used in F0) based on statistical power analysis . Breeding pairs were fed A. nauplii twice a day (approximately 60 mg/fish/d).…”

Section: Methodsmentioning

confidence: 99%

Medaka extended one‐generation reproduction test evaluating 4‐nonylphenol

Watanabe

Horie

Takanobu

et al. 2017

Enviro Toxic and Chemistry

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The medaka extended one-generation test (MEOGRT) was developed as a multigenerational toxicity test for chemicals, particularly endocrine-disrupting chemicals. Briefly, 3 generations of Japanese medaka (Oryzias latipes) are exposed to a chemical over a 20-wk period: 3 wk in the parental generation (F0), 15 wk in the first generation (F1), and 2 wk in the second generation (F2). The present study reports the first MEOGRT results concerning branched isomer mixtures of 4-nonylphenol (NP). Adult F0 medaka exposed to NP at 5 actual concentrations (1.27, 2.95, 9.81, 27.8, 89.4 µg/L) were unaffected in terms of reproduction, although vitellogenin in the male liver was increased dose-dependently at concentration of 2.95 µg/L and higher. In F1, in contrast, total egg (fecundity), fertile egg, and fertility decreased as NP increased; lowest-observed-effect concentrations (LOECs) for total egg, fertile egg, and fertility were 1.27, 1.27, 27.8 µg/L, respectively. In F1, but not in F0, secondary sex characteristics (i.e., anal fin papillae in males) were suppressed at 27.8 µg/L NP. Vitellogenin induction in adult male fish was slightly weaker in F1 than it was in F0, however. Gonadal sex abnormality and sex reversal occurred at 27.8 and 89.4 µg/L NP in F1 subadults. At 89.4 µg/L NP, all genotypic F1 males in breeding pairs had female phenotype, and some even demonstrated spawning. Concentrations of NP lower than 89.4 µg/L did not affect F2 survival or hatching. The highest detected NP level in environmental freshwater in Japan was approximately a half of the LOEC (1.27 µg/L for F1 fecundity); in other countries, however, environmental concentrations above the LOEC are reported, suggesting that NP may be affecting fish populations. Environ Toxicol Chem 2017;36:3254-3266. © 2017 SETAC.

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The effects of continuous diazinon exposure on growth and reproduction in Japanese medaka using a modified Medaka Extended One Generation Reproduction Test (MEOGRT)

Flynn

Lothenbach

Whiteman

et al. 2018

Ecotoxicology and Environmental Safety

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The influence of control group reproduction on the statistical power of the Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT)

Cited by 3 publications

References 10 publications

Summary of the development the US Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT) using data from 9 multigenerational medaka tests

Summary of the development the US Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT) using data from 9 multigenerational medaka tests

Medaka extended one‐generation reproduction test evaluating 4‐nonylphenol

The effects of continuous diazinon exposure on growth and reproduction in Japanese medaka using a modified Medaka Extended One Generation Reproduction Test (MEOGRT)

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