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Overview of Our Zebrafish Facility and Research With Larval Zebrafish (Danio rerio)
Citation:
Hedge, J. Overview of Our Zebrafish Facility and Research With Larval Zebrafish (Danio rerio). University of Washington, School of Medicine Department of Comparative Medicine, Veterinary Residents Seminar Series, Seattle, Washington, May 14, 2020. https://doi.org/10.23645/epacomptox.12290648
Impact/Purpose:
The Environmental Protection Agency (EPA) in Research Triangle Park’s (RTP) Zebrafish Research Facility consists of a network of recirculating housing rack systems which house the zebrafish breeding colony used primarily to produce embryos for developmental neurotoxicology research. All research conducted in the facility is approved by the EPA-RTP Institutional Animal Care and Use Committee (IACUC) and the facility is accredited by the Assessment and Accreditation of Laboratory Animal Care (AAALAC) International. Environmental parameters and water quality are carefully maintained within target ranges and biosecurity is well controlled through approved operating procedures and emergency plans. In an effort to screen and prioritize chemicals for developmental neurotoxicology, the EPA is utilizing non-mammalian models and higher throughput testing approaches including zebrafish larval assays and behavioral endpoints. These results illustrate the importance of morphological assessment and reporting in zebrafish larval locomotor behavior testing, because variables such as swim bladder inflation status or minor dysmorphology could have profound effects. There are many intrinsic factors that can affect the results of chemical exposures which should be monitored, reported, and controlled for sound science.
Description:
The Environmental Protection Agency (EPA) in Research Triangle Park’s (RTP) Zebrafish Research Facility consists of a network of recirculating housing rack systems which house the zebrafish breeding colony used primarily to produce embryos for developmental neurotoxicology research. All research conducted in the facility is approved by the EPA-RTP Institutional Animal Care and Use Committee (IACUC) and the facility is accredited by the Assessment and Accreditation of Laboratory Animal Care (AAALAC) International. Environmental parameters and water quality are carefully maintained within target ranges and biosecurity is well controlled through approved operating procedures and emergency plans. In an effort to screen and prioritize chemicals for developmental neurotoxicology, the EPA is utilizing non-mammalian models and higher throughput testing approaches including zebrafish larval assays and behavioral endpoints. Previous research elucidating the effects on larval locomotor behavior in response to time after the lights come on, light intensity, and typical responses to a representative organophosphate pesticide in using these behavioral tests is reviewed. With behavioral testing, careful consideration of intrinsic and extrinsic experimental confounders is essential. Morphological assessment is one such confounder that could have dramatic effects on behavior yet is rarely addressed adequately in publications. A study of ~1600 control zebrafish larvae was examined. On day 6 of development, larval behavior was assessed using a 40 minutes light and dark phase locomotor test. After testing, larvae were assessed for survival, hatching status, and dysmorphology (e.g., edema, spinal curvature and swim bladder non-inflation). Results demonstrate that normal larvae with inflated swim bladders showed 3X more activity in the light phase as normal larvae with uninflated swim bladders, showing that swim bladder status profoundly affects activity. Conversely, when comparing normal larvae with uninflated swim bladders versus abnormal larvae with uninflated swim bladders, normal larvae with uninflated swim bladders showed 4.5X more activity as abnormal larvae with uninflated swim bladders, demonstrating dysmorphology itself affects behavior. These results illustrate the importance of morphological assessment and reporting in zebrafish larval locomotor behavior testing, because variables such as swim bladder inflation status or minor dysmorphology could have profound effects. There are many intrinsic factors that can affect the results of chemical exposures which should be monitored, reported, and controlled for sound science. This abstract does not necessarily reflect official USEPA policy.
URLs/Downloads:
DOI: Overview of Our Zebrafish Facility and Research With Larval Zebrafish (Danio rerio)
HEDGE_ZEBRAFISH_UWASH_MAY14_2020_SEMINAR.PDF (PDF, NA pp, 4629.675 KB, about PDF)