title: Catbirds are the New Chickens: High Sensitivity to a Dioxin-like Compound in a Wildlife Species.
abstract: Dioxins and dioxin-like compounds (DLCs) are highly toxic and persistent global pollutants with extremely large differences in sensitivity across taxonomic groups. The chicken has long been considered uniquely sensitive to DLCs among avian species; but DLC toxicity in nondomesticated birds is largely untested, and the relevance of the chicken as an ecological model is uncertain. New approaches that use genotyping of the AHR1 ligand binding domain to screen for DLC sensitivity among avian species predicted that the gray catbird, a relevant wildlife species, is also highly sensitive. We tested this prediction using egg injections of a dioxin-like PCB (PCB-126) and found that the catbird is at least as sensitive as the chicken to DLCs, based on both embryotoxicity and mRNA induction of phase I metabolizing enzymes (CYP1A4/5). This study is the first to confirm that there are wildlife species as sensitive as the chicken and demonstrates how using predictive genotyping methods and targeted bioassays can focus toxicity assessments on ecologically relevant species.
authors.affiliation: Science and Technology Branch, Environment and Climate Change Canada , 5421 Robertson Road, Delta, British Columbia V4K 3N2, Canada.
authors.forename: Margaret L
authors.identifier: http://orcid.org/0000-0002-4217-619X
authors.initials: ML
authors.lastname: Eng
authors.affiliation: Science and Technology Branch, Environment and Climate Change Canada , 5421 Robertson Road, Delta, British Columbia V4K 3N2, Canada.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Bishop
authors.affiliation: Science and Technology Branch, Environment and Climate Change Canada , 1125 Colonel By Drive, Raven Road, Ottawa, Ontario K1A 0H3, Canada.
authors.forename: Doug
authors.identifier: http://orcid.org/0000-0003-2915-4989
authors.initials: D
authors.lastname: Crump
authors.affiliation: Science and Technology Branch, Environment and Climate Change Canada , 1125 Colonel By Drive, Raven Road, Ottawa, Ontario K1A 0H3, Canada.
authors.forename: Stephanie P
authors.initials: SP
authors.lastname: Jones
authors.affiliation: Department of Biological Sciences, Simon Fraser University , 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Tony D
authors.initials: TD
authors.lastname: Williams
authors.affiliation: Great Lakes Institute for Environmental Research, University of Windsor , 401 Sunset Avenue, Windsor, Ontario N9B 3P4, Canada.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Drouillard
authors.affiliation: Science and Technology Branch, Environment and Climate Change Canada , 5421 Robertson Road, Delta, British Columbia V4K 3N2, Canada.|Department of Biological Sciences, Simon Fraser University , 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: John E
authors.initials: JE
authors.lastname: Elliott
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000378:metabolism; D002645:Chickens / Q000378:metabolism*; D004147:Dioxins / Q000378:metabolism*; D005838:Genotype; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism
chemical_list: D004147:Dioxins; D018336:Receptors, Aryl Hydrocarbon