Molecular evidence predicts aryl hydrocarbon receptor ligand insensitivity in the peregrine falcon (Falco peregrines)

• Published in: European Journal of Wildlife Research
• Main Authors: Fujisawa, Nozomi, Ikenaka, Yoshinori, Kim, Eun-Young, Lee, Jin-Seon, Iwata, Hisato, Ishizuka, Mayumi
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer-Verlag
• Subjects: Avian; Dioxin; Raptor; Falcon; Aryl hydrocarbon receptor; 488; peregrine falcon
• Online Access: http://hdl.handle.net/2115/51759; https://doi.org/10.1007/s10344-011-0559-1

Some wild populations of fish-eating birds and raptors are exposed to high concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds such as other 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and coplanar polychlorinated biphenyls, resulting in accumulation in their tissues. It has been demonstrated that TCDD-like chemicals cause toxic effects via aryl hydrocarbon receptor (AHR)-mediated signaling pathways. The aim of this study was to characterize the AHR from the peregrine falcon (Falco peregrines) to predict its sensitivity to TCDD-like chemicals. The AHR1, AHR2, and AHR nuclear translocator (ARNT) 1 of the peregrine falcon are more similar in amino acid sequence to avian species less sensitive to TCDD-like chemicals such as the cormorant (95%) than to more sensitive species such as the chicken (90%). From the amino acid sequence, it is likely that the ligand-binding affinity of peregrine falcon AHR1 and AHR2 would be very low compared with the chicken or other sensitive species, and it was actually proved by an in vitro reporter gene assay. We concluded that the peregrine falcon, one of raptor species, may be relatively resistant to TCDD-like chemicals.