You are here:
Validation of a Fish Short-term Reproduction Assay
Citation:
MEILLER, J., G. T. ANKLEY, A. CHEEK, C. GRIM, R. HALL, K. M. JENSEN, I. R. SCHULTZ, AND L. TOUART. Validation of a Fish Short-term Reproduction Assay. Presented at SETAC Annual Meeting, Tampa, FL, November 18 - 22, 2008.
Impact/Purpose:
The Fish Short-term Reproduction Assay is an in vivo assay conducted with fathead minnows and is designed to detect changes in spawning, gross morphology, histopathology, and specific biochemical endpoints that reflect disturbances in the hypothalamic-pituitary-gonadal (HPG) axis.
Description:
The Fish Short-term Reproduction Assay is an in vivo assay conducted with fathead minnows and is designed to detect changes in spawning, gross morphology, histopathology, and specific biochemical endpoints that reflect disturbances in the hypothalamic-pituitary-gonadal (HPG) axis. This assay has undergone a rigorous validation process in order to be proposed as one of the assays in the Tier 1 screening battery of the Endocrine Disruptor Screening Program at the U.S. Environmental Protection Agency. Tier 1 assays are intended to provide evidence that suggests certain endocrine-regulated processes may be sufficiently perturbed to warrant more definitive testing. The validation process used was based on the principles developed by the U.S. Interagency Coordinating Committee for the Validation of Alternative Methods (ICCVAM) and the Organization for Economic Co-operation and Development (OECD). The core endpoints in the assay include survival, behavior, fecundity and fertilization success, appearance and secondary sex characteristics, gonad histology, and biochemical endpoints measuring sex steroids (estradiol and testosterone) and the egg yolk precursor protein vitellogenin. Some endpoints are highly diagnostic (e.g., vitellogenin induction in males, male nuptial tubercle formation in females), and may assist in identifying specific cellular mechanisms of action; others are less diagnostic of direct endocrine mechanisms of action, but collectively this suite of endpoints allows inferences to be made with regard to possible endocrine disturbances and thus provides guidance for further testing. The reproducibility of this assay has been broadly demonstrated using a number of representative endocrine-active chemicals across geographically diverse laboratories. In the final stages of the validation process for this assay, a peer review panel was asked to comment on the clarity of the assay’s purpose and the assay test protocol with regard to the objective, measured endpoints, strengths and limitations, reproducibility, and performance criteria. The outcome of peer review and recommendations regarding the assay will also be discussed.