Fig. 3.

Light-dependent cAMP increase mediated by the opsin-based pigment. (A) A cAMP increase caused by light irradiation was observed in HEK293S cells transfected with the box jellyfish opsin cDNA (jellyfish opsin) but not in cells transfected with expression vector alone (mock). n = 3. As a control, the cAMP increase caused by the agonist isoprotenol (ISO) in HEK293S cells transfected with human β₂-adrenergic receptor cDNA was measured (n = 3). (B) Light-dependent cAMP increase in the box jellyfish eyes. The amounts of cAMP extracted from dark-adapted (Dark) and irradiated rhopalia containing eyes (Light) were compared (n = 3). Error bars represent SEM. (C) Immunofluorescence labeling of outer segments of the box jellyfish visual cells with the anti-adenylyl cyclase antibody (magenta). (Scale bar: 100 μm.)