| Autor: |
Pesce E; Laboratoire WatchFrog S.A., 1 Rue Pierre Fontaine, 91000 Évry, France.; UMR 7221 Physiologie Moléculaire et Adaptation, CNRS, Muséum National d'Histoire Naturelle, CP32, 7 rue Cuvier, 75005 Paris, France., Garde M; Laboratoire WatchFrog S.A., 1 Rue Pierre Fontaine, 91000 Évry, France., Rigolet M; UMR 7221 Physiologie Moléculaire et Adaptation, CNRS, Muséum National d'Histoire Naturelle, CP32, 7 rue Cuvier, 75005 Paris, France., Tindall AJ; Laboratoire WatchFrog S.A., 1 Rue Pierre Fontaine, 91000 Évry, France., Lemkine GF; Laboratoire WatchFrog S.A., 1 Rue Pierre Fontaine, 91000 Évry, France., Baumann LA; University of Heidelberg, Centre for Organismal Studies, Aquatic Ecology and Toxicology, Im Neuenheimer Feld 504, 69120 Heidelberg, Germany.; Vrije Universiteit Amsterdam, Amsterdam Institute for Life and Environment, Section Environmental Health & Toxicology, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands., Sachs LM; UMR 7221 Physiologie Moléculaire et Adaptation, CNRS, Muséum National d'Histoire Naturelle, CP32, 7 rue Cuvier, 75005 Paris, France., Du Pasquier D; Laboratoire WatchFrog S.A., 1 Rue Pierre Fontaine, 91000 Évry, France. |
| Abstrakt: |
Identifying endocrine disrupting chemicals in order to limit their usage is a priority and required according to the European Regulation. There are no Organization for Economic Co-operation and Development (OECD) test guidelines based on fish available for the detection of Thyroid axis Active Chemicals (TACs). This study aimed to fill this gap by developing an assay at eleuthero-embryonic life stages in a novel medaka ( Oryzias latipes ) transgenic line. This transgenic line expresses green fluorescent protein (GFP) in thyrocytes, under the control of the medaka thyroglobulin gene promoter. The fluorescence expressed in the thyrocytes is inversely proportional to the thyroid axis activity. When exposed for 72 h to activators (triiodothyronine (T 3 ) and thyroxine (T 4 )) or inhibitors (6- N -propylthiouracil (PTU), Tetrabromobisphenol A (TBBPA)) of the thyroid axis, the thyrocytes can change their size and express lower or higher levels of fluorescence, respectively. This reflects the regulation of thyroglobulin by the negative feedback loop of the Hypothalamic-Pituitary-Thyroid axis. T 3 , T 4 , PTU, and TBBPA induced fluorescence changes with the lowest observable effect concentrations (LOECs) of 5 μg/L, 1 μg/L, 8 mg/L, and 5 mg/L, respectively. This promising tool could be used as a rapid screening assay and also to help decipher the mechanisms by which TACs can disrupt the thyroid axis in medaka. |
