Meeting Abstract

P3.25  Friday, Jan. 6  Cloning of the opsin gene in longtooth grouper (Epinephelus bruneus) MATSUMOTO, Taro*; ISHIBASHI, Yasunori; Kinki Univ, Nara, Japan; Kinki Univ, Nara, Japan ns_taro@nara.kindai.ac.jp

The visual systems of aquatic animals have adapted to various light environments, depending on the habitat. The longtooth grouper is a large reef-associated fish. We cloned opsin genes from the grouper to identify visual adaptations of this species to the light environment of its particular habitat. Three longtooth grouper fish aged 2 years (standard length [SL], 258–300 mm) were obtained from Shirahama Experiment Station, Fisheries Laboratory, Kinki University. The total RNA was extracted from the retina or whole body of the fish. Opsin genes were cloned using reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends-PCR (RACE-PCR). We found 4 types of opsin gene fragments including Rh1 (rhodopsin), SWS2 (blue sensitive), MWS (green sensitive), and LWS (yellow-red sensitive). The full-length open reading frame of Rh1 was 1059 bp. Our results suggest that the vision of the longtooth grouper is sensitive to blue through yellow-red light. This wide spectrum may be advantageous for the light environment from surface water to the sea bottom. We will investigate opsin expression in larvae (0–60 days after hatching) and in young fish (1 year old; SL, 220–235 mm).