Aryl hydrocarbon receptors in the frog Xenopus laevis: two AhR1 paralogs exhibit low affinity for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

ABSTRACT: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent developmental toxicant in most vertebrates. However, frogs are relatively insensitive to TCDD toxicity, especially during early life stages. Toxicity of TCDD and related halogenated aromatic hydrocarbons is mediated by the aryl hydrocarbon receptor (AhR), and specific differences in properties of the AhR signaling pathway can underlie in TCDD toxicity in different species. This study investigated the role of AhR in frog TCDD insensitivity, using Xenopus laevis as a model system. X. laevis, a pseudotetraploid species, expresses two distinct AhR1 genes, AhR1alpha and AhR1beta. Sharing 86% amino acid identity, these likely represent distinct genes, both orthologous to mammalian AhR and paralogous to the AhR2 gene(s) in most fish. Both AhR

SUBMITTER: Lavine JA 

PROVIDER: S-EPMC1255970 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature