title: Thyroid hormone receptor-β gene expression in the brain of the frog Pelophylax esculentus: seasonal, hormonal and temperature regulation.
abstract: Thyroid hormone receptor-β (trβ) cDNA was identified in the adult of Pelophylax esculentus (previously: Rana esculenta), a seasonally breeding species, in order to detect spatial brain trβ expression, its levels through the seasons and in response to 6-n-propyl-2-thiouracil, T(4) and T(3) administrations as well as to thermal manipulations. The deduced amino acid sequence of P. esculentus trβ showed a high similarity to the homologous of other vertebrates. By in situ hybridization we found trβ mRNA signal in the anterior preoptic nucleus, the habenulae, the hypothalamic-pituitary region and the ependyma. Brain trβ transcript levels varied through the seasons, and they were well correlated with brain T(4) levels but only partially with T(3) levels. Experimentally-induced hypothyroidism decreased brain trβ expression. The administration of exogenous thyroid hormones increased brain trβ expression, with T(4) appearing more potent than T(3). The experiments of thermal manipulations further strengthen the hypothesis that T(4) is more effective than T(3) in brain trβ regulation. This study also shows that, as in other vertebrates, deiodinase enzymes could modulate trβ expression via thyroid hormone regulation.
authors: Dipartimento di Scienze della Vita, Seconda Università di Napoli, via Vivaldi 43, 81100 Caserta, Italy.
authors: Alessandra
authors: A
authors: Santillo
authors: Lavinia
authors: L
authors: Burrone
authors: Diana
authors: D
authors: Ferrara
authors: Sergio
authors: S
authors: Minucci
authors: Claudia
authors: C
authors: Pinelli
authors: Gabriella
authors: G
authors: Chieffi Baccari
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D011893:Rana esculenta / Q000378:metabolism*; D012621:Seasons; D013696:Temperature; D037042:Thyroid Hormone Receptors beta / Q000378:metabolism*; D013963:Thyroid Hormones / Q000494:pharmacology
chemical_list: D037042:Thyroid Hormone Receptors beta; D013963:Thyroid Hormones