title: Anatomical distribution and daily profile of gper1b gene expression in brain and peripheral structures of goldfish (Carassius auratus).
abstract: The functional organization of the circadian system and the location of the main circadian oscillators vary through phylogeny. Present study investigates by in situ hybridization the anatomical location of the clock gene gPer1b in forebrain and midbrain, pituitary, and in two peripheral locations, the anterior intestine and liver, in a teleost fish, the goldfish (Carassius auratus). Moreover, the daily expression profiles of this gene were also studied by quantitative Real Time-PCR. Goldfish were maintained under a 12L-12D photoperiod and fed daily at 2 h after lights were switched on. A wide distribution of gPer1b mRNA in goldfish brain and pituitary was found in telencephalon, some hypothalamic nuclei (including the homologous to mammalian SCN), habenular nucleus, optic tectum, cerebellum and torus longitudinalis. Moreover, gPer1b expression was observed, for the first time in teleosts, in the pituitary, liver and anterior intestine. Day/night differences in gper1b mRNA abundance were found by in situ hybridization, with higher signal at nighttime that correlates with the results obtained by RT-PCR, where a rhythmic gPer1b expression was found in all tissues with acrophases at the end of the night. Amplitudes of gper1b rhythms vary among tissues, being higher in liver and intestine than in the brain, maybe because different cues entrain clocks in these locations. These results support the existence of functional clocks in many central and peripheral locations in goldfish coordinated, ticking at the same time.
authors.affiliation: a Departamento de Fisiología (Fisiología Animal II) , Facultad de Biología, Universidad Complutense de Madrid , Madrid , Spain and.
authors.forename: Aída
authors.initials: A
authors.lastname: Sánchez-Bretaño
authors.forename: Marie-M
authors.initials: MM
authors.lastname: Gueguen
authors.forename: Joel
authors.initials: J
authors.lastname: Cano-Nicolau
authors.forename: Olivier
authors.initials: O
authors.lastname: Kah
authors.forename: Ángel L
authors.initials: ÁL
authors.lastname: Alonso-Gómez
authors.forename: María J
authors.initials: MJ
authors.lastname: Delgado
authors.forename: Esther
authors.initials: E
authors.lastname: Isorna
mesh_terms: D000818:Animals; D001683:Biological Clocks; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm; D003001:Cloning, Molecular; D005260:Female; D005786:Gene Expression Regulation; D006054:Goldfish / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D007413:Intestinal Mucosa / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D056950:Period Circadian Proteins / Q000235:genetics* / Q000378:metabolism*; D017440:Photoperiod; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D056950:Period Circadian Proteins; D012333:RNA, Messenger
keywords: Brain; circadian system; clock gene; in situ hybridization; intestine; liver; pituitary