Tadpole skin dies autonomously in response to thyroid hormone at metamorphosis.
نویسندگان
چکیده
Transgenic tadpoles that express a dominant negative thyroid hormone (TH) receptor specifically in their skin undergo normal metamorphosis, with one exception: they retain a larval epidermis over the developing adult epithelium. TH-induced death of the tadpole epidermis is inhibited by the dominant negative TH receptor whereas the TH-induced response of the neighboring fibroblasts and the cells that form the adult skin occur normally. Therefore death of the tadpole skin is a direct and cell autonomous target of TH, and its protection has no detectable influence on TH-induced changes of other cell types.
منابع مشابه
Growth hormone is a weaker candidate than prolactin for the hormone responsible for the development of a larval-type feature in cultured bullfrog skin.
Prolactin (PRL) has, for some years, been considered to be the 'juvenile hormone' in amphibians. Recently, growth hormone (GH) has been proposed as another candidate, because in the larval stages the expression of the mRNA GH is high but it is downregulated in the climax stages of metamorphosis or following treatment with thyroid hormone. In the present study, we investigated whether GH promote...
متن کاملMolecular mechanisms of corticosteroid synergy with thyroid hormone during tadpole metamorphosis.
Corticosteroids (CS) act synergistically with thyroid hormone (TH) to accelerate amphibian metamorphosis. Earlier studies showed that CS increase nuclear 3,5,3'-triiodothyronine (T(3)) binding capacity in tadpole tail, and 5' deiodinase activity in tadpole tissues, increasing the generation of T(3) from thyroxine (T(4)). In the present study we investigated CS synergy with TH by analyzing expre...
متن کاملThe molecular basis of thyroid hormone-dependent central nervous system remodeling during amphibian metamorphosis.
Tadpole metamorphosis involves a coordinated series of changes in virtually every tissue of the body. This developmental process is induced by the single morphogen, thyroid hormone (TH). The amphibian central nervous system (CNS) is a primary target for TH, and it undergoes dramatic morphological and cytoarchitectural changes in response to the hormone. TH acts by regulating gene expression and...
متن کاملCrossregulation of the Thyroid Hormone and Corticosteroids in Amphibians and Fish: The Effects of Endocrine Disruption
Thyroid hormones are involved in many physiological processes, during growth, develop‐ ment, behaviour, stress. Their actions are mediated by TH receptors (TR-alpha and TR-beta), which are members of the nuclear receptor (NR) superfamily and function as ligand-activat‐ ed transcription factors. In amphibians, TR-alpha is expressed shortly after hatching and is maintained at a relatively constan...
متن کاملA Mechanism to Enhance Cellular Responsivity to Hormone Action: Krüppel-Like Factor 9 Promotes Thyroid Hormone Receptor-β Autoinduction During Postembryonic Brain Development.
Thyroid hormone (TH) receptor (TR)-β (trb) is induced by TH (autoinduced) in Xenopus tadpoles during metamorphosis. We previously showed that Krüppel-like factor 9 (Klf9) is rapidly induced by TH in the tadpole brain, associates in chromatin with the trb upstream region in a developmental stage and TH-dependent manner, and forced expression of Klf9 in the Xenopus laevis cell line XTC-2 accelera...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 100 4 شماره
صفحات -
تاریخ انتشار 2003