Diverse developmental programs of Xenopus laevis metamorphosis are inhibited by a dominant negative thyroid hormone receptor

Metamorphosis of anuran tadpoles is controlled by thyroid hormone (TH). Her e we demonstrate that transgenic Xenopus laevis tadpoles expressing a domin ant negative form of TH receptor-a are resistant to a wide variety of the m etamorphic changes induced by TH. This result confirms that TH receptors me diate both early and late developmental programs of metamorphosis as divers e as growth in the brain, limb buds, nose and Meckel's cartilage, remodelin g of the intestine, and death and resorption of the gills and tail.