Table 1.
Evolution of vitamin A-based light sensors (opsins) from bacteria to humans. The symbol # denotes the sensing of light by visual pigments for the circadian clock and pupillary reflex. Due to the tremendous diversity of opsins and space limitation, this table only depicts opsins that are representative of each kind. Opsin homologs (e.g., RGR in mammals) that function as light-dependent retinoid isomerases are not included.
| Kingdom | Species | Photoreceptor Cell or Structure | Physiological Functions | Photoreceptor Proteins | Retinal Chomophore |
|---|---|---|---|---|---|
| Animalia |
Homo sapiens Human |
Cones | High luminescence vision and color vision + # | Long-wave cone pigment | 11-cis retinal |
| Medium-wave cone pigment | |||||
| Short-wave cone pigment | |||||
| Rod | Low luminescence vision + # | Rhodopsin | |||
| Light-sensitive ganglion cell | Light-sensing for the circadian clock and papillary reflex (#) | Melanopsin | |||
|
Mus musculus Mouse |
Cones | High luminescence vision and color vision + # | Medium-wave cone pigment UV cone pigment |
11-cis retinal | |
| Rod | Low luminescence vision + # | Rhodopsin | |||
| Light-sensitive ganglion cell | Light-sensing for the circadian clock and papillary reflex (#) | Melanopsin | |||
|
Gallus gallus Chicken |
Cones | High luminescence vision and color vision + # | Long-wave cone pigment Medium-wave cone pigment Short-wave cone pigment UV cone pigment |
11-cis retinal | |
| Rod | Low luminescence vision + # | Rhodopsin | |||
| Light-sensitive ganglion cell | Light-sensing for the circadian clock and papillary reflex (#) | Melanopsin | |||
| pinealocyte | Regulation of pineal circadian cycle | Pinopsin | |||
|
Rana catesbeiana Frog |
Rod and cones of adult frog | Vision on land and in water | Visual pigments | 11-cis retinal | |
| Photosensitive melanophore | Light-dependent melanosome migration | Melanopsin | |||
| Rod and cones of tadpole | Vision in water | Visual pigments | 11-cis-3,4-dehydroretinal | ||
|
Watasenia scintillans Squid |
Retinal photoreceptors | Vision in water | Visual pigments | 11-cis-3,4-dehydroretinal | |
| 11-cis-4-hydroxyretinal | |||||
| 11-cis retinal | |||||
|
Drosophila melanogaster Fly |
R1 to R7 photoreceptors | Vision | Visual pigments | 11-cis-3-hydroxyretinal | |
| Plantae |
Chlamydomonas reinhardtii Green algea |
Eye spot | Phototactic response | Chlamyopsin | All-trans retinal |
| Photophobic response | |||||
| Monera |
Halobacterium halobium Bacteria |
Halobacterium halobium | Light-driven chloride pump | Halorhodopsin | All-trans retinal |
| Light-driven proton pump | Bacteriorhodopsin | ||||
| Phototactic response | Sensory rhodopsin I | ||||
| Photophobic response | Sensory rhodopsin II |