title: Molecular cloning and expression of long-wavelength-sensitive cone opsin in the brain of a tropical damselfish.
abstract: Ovarian development of the sapphire devil, Chrysiptera cyanea, exhibits photoperiodism and is stimulated under long-day conditions. Previous studies suggest that red light is more effective than green and blue lights for inducing ovarian development. In addition, the extra-retinal photoreception involved in the ovarian development is suggested in this species. The present study aimed to clone the red-light-sensitive cone opsin (sdLWS) of this species, to demonstrate its expression in the brain, and to confirm the effectiveness of red light on the initiation of ovarian development. A phylogenetic analysis revealed that sdLWS belongs to the long-wavelength-sensitive opsin (LWS opsin) group, showing high identity (77-92%) with the LWS opsin of other fishes. RT-PCR showed that sdLWS is expressed in the eye, brain, and ovary. In situ hybridization indicated that sdLWS is expressed in the third ventricle periventricular area in the anterior hypothalamus. Exposing fish to long-day conditions of red light resulted in the appearance of vitellogenic oocytes in the ovary and an increase in the gonadosomatic index within 2weeks, suggesting that fish immediately undergo oocyte development under red light conditions. These results indicate that sdLWS is a possible candidate of deep brain photoreceptor molecule involved in photoperiodic ovarian development in the sapphire devil.
authors.affiliation: Graduate School of Engineering and science, University of the Ryukyus, Senbaru, Nishihara, Okinawa, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Mohammad Abu Jafor
authors.initials: MA
authors.lastname: Bapary
authors.forename: Syugo
authors.initials: S
authors.lastname: Igarashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Imamura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sawada
authors.forename: Mio
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Sung-Pyo
authors.initials: SP
authors.lastname: Hur
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takemura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm; D003001:Cloning, Molecular; D055358:Cone Opsins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008027:Light; D008969:Molecular Sequence Data; D009865:Oocytes / Q000254:growth & development* / Q000502:physiology; D010473:Perciformes / Q000235:genetics / Q000378:metabolism*; D010786:Photoreceptor Cells / Q000378:metabolism; D010802:Phylogeny
chemical_list: D055358:Cone Opsins