Journal of Comparative Physiology B

, Volume 182, Issue 5, pp 673–685

Cloning, tissue expression pattern and daily rhythms of Period1, Period2, and Clock transcripts in the flatfish Senegalese sole, Solea senegalensis

  • Águeda J. Martín-Robles
  • David Whitmore
  • Francisco Javier Sánchez-Vázquez
  • Carlos Pendón
  • José A. Muñoz-Cueto
Original Paper

DOI: 10.1007/s00360-012-0653-z

Cite this article as:
Martín-Robles, Á.J., Whitmore, D., Sánchez-Vázquez, F.J. et al. J Comp Physiol B (2012) 182: 673. doi:10.1007/s00360-012-0653-z

Abstract

An extensive network of endogenous oscillators governs vertebrate circadian rhythmicity. At the molecular level, they are composed of a set of clock genes that participate in transcriptional–translational feedback loops to control their own expression and that of downstream output genes. These clocks are synchronized with the environment, although entrainment by external periodic cues remains little explored in fish. In this work, partial cDNA sequences of clock genes representing both positive (Clock) and negative (Period1, Period2) elements of the molecular feedback loops were obtained from the nocturnal flatfish Senegalese sole, a relevant species for aquaculture and chronobiology. All of the above genes exhibited high identities with their respective teleost clock genes, and Per–Arnt–Sim or basic helix–loop–helix binding domains were recognized in their primary structure. They showed a widespread distribution through the animal body and some of them displayed daily mRNA rhythms in central (retina, optic tectum, diencephalon, and cerebellum) and peripheral (liver) tissues. These rhythms were most robust in retina and liver, exhibiting marked Period1 and Clock daily oscillations in transcript levels as revealed by ANOVA and cosinor analysis. Interestingly, expression profiles were inverted in retina and optic tectum compared to liver. Such differences suggest the existence of tissue-dependent zeitgebers for clock gene expression in this species (i.e., light for retina and optic tectum and feeding time for liver). This study provides novel insight into the location of the molecular clocks (central vs. peripheral) and their different phasing and synchronization pathways, which contributes to better understand the teleost circadian systems and its plasticity.

Keywords

Clock genes Fish Central nervous system Liver Light Feeding 

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Águeda J. Martín-Robles
    • 1
    • 2
    • 3
  • David Whitmore
    • 4
  • Francisco Javier Sánchez-Vázquez
    • 5
  • Carlos Pendón
    • 2
  • José A. Muñoz-Cueto
    • 1
    • 3
  1. 1.Departamento de Biología, Facultad de Ciencias del Mar y AmbientalesUniversidad de CádizPuerto RealSpain
  2. 2.Departamento de Biomedicina, Biotecnología y Salud Pública, Facultad de CienciasUniversidad de CádizPuerto RealSpain
  3. 3.CACYTMAR, Institutos de InvestigaciónPuerto RealSpain
  4. 4.Department of Cell and Developmental Biology, Centre for Cell and Molecular DynamicsUniversity College of LondonLondonUK
  5. 5.Departamento de Fisiología, Facultad de BiologíaUniversidad de MurciaMurciaSpain