title: cDNA cloning of an aryl hydrocarbon receptor from Baikal seals (Phoca sibirica).
abstract: Species differences in sensitivity to related planar halogenated aromatic hydrocarbons (PHAH) add significant uncertainty in assessing the ecological risk to aquatic mammals. To investigate mechanisms of PHAH sensitivity in aquatic mammals, we cloned and sequenced the cDNA of Baikal seal aryl hydrocarbon receptor (AHR), an intracellular protein that initiates PHAH-mediated effects. The Baikal seal AHR cDNA has an open reading frame of 843 amino acid residues with a predicted molecular mass of 94.6 kDa. Comparison of AHR amino acid sequences indicated a high degree of sequence conservation (98%) between Baikal and harbor seals. The high conservation of AHRs between Baikal and harbor seals indicates that these seals express AHR proteins closely related structurally. In our previous report (Kim & Hahn, 2002), the dioxin-binding affinity of the harbor seal AHR was at least as high as that of the AHR from a dioxin-sensitive strain of mice, suggesting that this seal species may be sensitive to PHAH effects. This implies that Baikal seal may also be sensitive to dioxin effects.
authors.affiliation: Environmental Chemistry and Ecotoxicology, Center for Marine Environmental Studies, Ehime University, Matsuyama, Japan. eykim@agr.ehime-u.ac.jp
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Mark E
authors.initials: ME
authors.lastname: Hahn
authors.forename: Hisato
authors.initials: H
authors.lastname: Iwata
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Tanabe
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Miyazaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D004147:Dioxins / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics*; D018570:Risk Assessment; D046048:Seals, Earless / Q000235:genetics* / Q000502:physiology; D017422:Sequence Analysis, DNA; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D004147:Dioxins; D011084:Polycyclic Aromatic Hydrocarbons; D018336:Receptors, Aryl Hydrocarbon; D014874:Water Pollutants, Chemical