Thyroid hormone signalling in early amphibian development

Abstract

Event Abstract Back to Event Thyroid hormone signalling in early amphibian development Barbara A. Demeneix1* 1 Museum Nationale d'Histoire Naturelle/ Centre National de Recherche Scientifique, Dept Regulations and Development, France The roles of thyroid hormones in postembryonic vertebrate development are amply characterized. Metamorphosis in anuran amphibians is one of the most striking examples of thyroid hormone effects in development, closely paralleled by similar thyroid hormone-dependent developmental transitions in other vertebrates, including the perinatal period in mammals. Gudernatsch’s observations on thyroid gland activation of metamorphosis were carried out in Prague in 1911 and published in 1912. Intriguingly, it was also in Prague in 1912 that Kafka's first version of his novel 'Metamorphosis' was edited. More than fifty years later in 1977, Leloup and Buscaglia working in the Natural history Museum in Paris, demonstrated the key role of T3 in amphibian metamorphosis. However, the actions of thyroid hormones in early, embryonic development are still a matter of debate. Recent data show numerous components of thyroid hormone signaling to be present in eggs and embryos of many species, raising the possibilities that either thyroid hormones functionally regulate target genes and key processes in early development. Using the free-living Xenopus embryo we have shown that not only thyroid hormone receptors (TRs) and the thyroid hormones, T4 and T3, but also deiodinases are found during early embryogenesis, well before the formation of the larval thyroid gland. These observations argue for ligand-dependent and/or ligand-independent actions of TRs during this period. To examine the effects of thyroid hormones in govering different processes in early development we took a candidate gene approach, identifying a number of genes regulated by thyroid hormone in embryos, notably in the brain. Given these arguments for active, endogenous T3 signaling in early embryonic brain, we next investigated the actions of the flame retardant TBBPA, known to alter TH signaling in other systems, on gene expression in early amphibian development. We conclude first, that TH signalling is functional during organogenesis, and second, that early neurogenesis in amphibians is a potential window for endocrine disruption. Acknowledgements Acknowledgments: Supported by EU projects Cascade, Crescendo Keywords: endocrine disruption, metamorphosis, Neurogenesis, thyroid Conference: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology, Ann Arbor, United States, 11 Jul - 13 Jul, 2011. Presentation Type: Plenary Topic: Hormones and development Citation: Demeneix BA (2011). Thyroid hormone signalling in early amphibian development. Front. Endocrinol. Conference Abstract: ISAREN 2011: 7th International Symposium on Amphibian and Reptilian Endocrinology and Neurobiology. doi: 10.3389/conf.fendo.2011.03.00009 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Prof. Barbara A Demeneix, Museum Nationale d'Histoire Naturelle/ Centre National de Recherche Scientifique, Dept Regulations and Development, Paris, 75321 cedex 5, France, bdem@mnhn.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Barbara A Demeneix Google Barbara A Demeneix Google Scholar Barbara A Demeneix PubMed Barbara A Demeneix Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.