Cloning of SWS1 gene and expression of five opsin genes in larval flounder Paralichthys olivaceus

Abstract:

Fish perceive light intensity and wavelength mainly through visual opsins. The 1 317 bp full-length SWS1 cDNA sequence of Paralichthys olivaceuswas first cloned in this research containing 1 077 bp length ORF, encoding 358 amino acid of cone opsin. It indicated that the larval flounder have the potential ability to perceive ultraviolet rays. In addition, qRT-PCR showed that the related expression of rod opsin RH1 and SWS1 had no significant changes. While the related expression of cone opsin genes RH2 and SWS2 was significantly enhanced from first hatched larvae to 13th day after hatching(DAH) larvae; LWS gene was significantly enhanced from DAH6, and then descend to DAH13 slowly. In eyes, furthermore, RNA whole mount in situ hybridization revealed that the signals of opsin genes were mainly expressed in the peripheral retina and crystal and SWS2 expressed later than other opsin genes. Unexpectedly, the expressions of opsin genes were found in skin, fins, gills, intestine and other tissues extensively.