title: Thyroid Hormone Signaling in the Mouse Retina.
abstract: Thyroid hormone is a crucial regulator of gene expression in the developing and adult retina. Here we sought to map sites of thyroid hormone signaling at the cellular level using the transgenic FINDT3 reporter mouse model in which neurons express β-galactosidase (β-gal) under the control of a hybrid Gal4-TRα receptor when triiodothyronine (T3) and cofactors of thyroid receptor signaling are present. In the adult retina, nearly all neurons of the ganglion cell layer (GCL, ganglion cells and displaced amacrine cells) showed strong β-gal labeling. In the inner nuclear layer (INL), a minority of glycineric and GABAergic amacrine cells showed β-gal labeling, whereas the majority of amacrine cells were unlabeled. At the level of amacrine types, β-gal labeling was found in a large proportion of the glycinergic AII amacrines, but only in a small proportion of the cholinergic/GABAergic 'starburst' amacrines. At postnatal day 10, there also was a high density of strongly β-gal-labeled neurons in the GCL, but only few amacrine cells were labeled in the INL. There was no labeling of bipolar cells, horizontal cells and Müller glia cells at both stages. Most surprisingly, the photoreceptor somata in the outer nuclear layer also showed no β-gal label, although thyroid hormone is known to control cone opsin expression. This is the first record of thyroid hormone signaling in the inner retina of an adult mammal. We hypothesize that T3 levels in photoreceptors are below the detection threshold of the reporter system. The topographical distribution of β-gal-positive cells in the GCL follows the overall neuron distribution in that layer, with more T3-signaling cells in the ventral than the dorsal half-retina.
authors.affiliation: Max Planck Institute for Brain Research, Max-von-Laue-Str., Frankfurt, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Arbogast
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon CEDEX 07, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Flamant
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon CEDEX 07, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Godement
authors.affiliation: VetCore/Imaging, University of Veterinary Medicine, Veterinärplatz 1, Vienna, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Glösmann
authors.affiliation: Max Planck Institute for Brain Research, Max-von-Laue-Str., Frankfurt, Germany.|Ernst Strüngmann Institute for Neuroscience, Deutschordenstr.,Frankfurt, Germany.
authors.forename: Leo
authors.identifier: http://orcid.org/0000-0002-8141-0911
authors.initials: L
authors.lastname: Peichl
mesh_terms: D000818:Animals; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000378:metabolism; D012160:Retina / Q000378:metabolism*; D015398:Signal Transduction; D013963:Thyroid Hormones / Q000378:metabolism*; D014284:Triiodothyronine / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D013963:Thyroid Hormones; D014284:Triiodothyronine; D001616:beta-Galactosidase