RT Journal Article T1 The liver of goldfish as a component of the circadian system: Integrating a network of signals A1 Sánchez Bretaño, Aída A1 Alonso Gómez, Ángel Luis A1 Delgado Saavedra, María Jesús A1 Isorna Alonso, Esther AB The circadian system drives daily physiological and behavioral rhythms that allow animals to anticipate cyclic environmental changes. The discovery of the known as ‘‘clock genes’’, which are very well conserved through vertebrate phylogeny, highlighted the molecular mechanism of circadian oscillators functioning, based on transcription and translation cycles (24 h) of such clock genes. Studies in goldfish have shown that the circadian system in this species is formed by a net of oscillators distributed at central and peripheral locations, as the retina, brain, gut and liver, among others. In this work we review the existing information about the hepatic oscillator in goldfish due to its relevance in metabolism, and its key role as target of a variety of humoral signals. Different input signals modify the molecular clockwork in the liver of goldfish. Among them, there are environmental cues (photocycle and feeding regime) and different encephalic and peripheral endogenous signals (orexin, ghrelin and glucocorticoids). Per clock genes seem to be a common target for different signals. Thus, this genes family might be important for shifting the hepatic oscillator. The physiological relevance of the crosstalking between metabolic and feeding-related hormones and the hepatic clock sets the stage for the hypothesis that these hormones could act as ‘‘internal zeitgebers’’ communicating oscillators in the goldfish circadian system. PB Academic Press SN 0016-6480, ESSN: 1095-6840 YR 2015 FD 2015-09 LK https://hdl.handle.net/20.500.14352/23302 UL https://hdl.handle.net/20.500.14352/23302 LA eng NO Ministerio de Economía y Competitividad (MINECO) DS Docta Complutense RD 3 may 2024