CLONING AND EXPRESSION OF A THYROID-HORMONE RECEPTOR ALPHA-1 IN THE PERENNIBRANCHIATE AMPHIBIAN PROTEUS-ANGUINUS

We demonstrated the presence of thyroid hormone receptor alpha mRNAs i n tissues of the perennibranchiate amphibian Proteus anguinus, which i s insensitive to thyroid hormone. From P. anguinus muscle we cloned an d sequenced the 3' coding and untranslated region of a cDNA correspond ing to a thyroid hormone receptor alpha 1. Using cDNA-PCR and in situ hybridization, we showed a tissue-specific expression of thyroid hormo ne receptor alpha genes, which was not upregulated by thyroid hormone as opposed to that observed in the TH-sensitive species, Xenopus laevi s.