title: Molecular cloning, tissue distribution and daily expression of cry1 and cry2 clock genes in European seabass (Dicentrarchus labrax).
abstract: Biological rhythms are driven by circadian oscillators, which are ultimately controlled by the cyclic expression of clock genes. Cryptochromes (CRY), blue light photoreceptors, belong to the negative elements of the transcriptional feedback loop into the molecular clock. This paper describes the cloning and characterization of two cryptochromes (cry1 and 2) in European seabass, which is considered an interesting chronobiology model due to its dual (diurnal/nocturnal) behavior. The cloned cDNA fragments encoded for two proteins of 567 and 668 amino acids, which included the FAD-binding and the DNA-photolyase domains. Moreover, both proteins had a high homology with cryptochrome proteins (Cry) of other teleost fish. These cry1 and 2 genes were expressed in several tissues of seabass (brain, liver, heart, retina, muscle, spleen, gill and intestine). In addition, the daily expression of cry1 was rhythmic in brain, heart and liver with the acrophase around ZT 03:15 h (after the onset of lights). Similarly, the cry2 daily expression was rhythmic in liver, peaking at ZT 03:28 h, whereas in brain the acrophase was at ZT 11:08 h (shortly prior to the offset of lights). These findings provide new elements to help understanding the functioning of the molecular clock of seabass.
authors: Department of Physiology, Faculty of Biology, Regional Campus of International Excellence Campus Mare Nostrum, University of Murcia, 30100, Murcia, Spain. adelpozo@um.es
authors: Ana
authors: A
authors: del Pozo
authors: Luisa M
authors: LM
authors: Vera
authors: Jose Antonio
authors: JA
authors: Sánchez
authors: Francisco Javier
authors: FJ
authors: Sánchez-Vázquez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass / Q000235:genetics* / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002940:Circadian Rhythm; D003001:Cloning, Molecular; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D005786:Gene Expression Regulation; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D017434:Protein Structure, Tertiary
chemical_list: D056931:Cryptochromes; D029941:Fish Proteins