photoreceptor, rhodopsin, retina, neurons, retinal, vasculature, visual cortex, opsin, zebrafish, chloroplasts, photopigment, macula, crystallin, axons, dpp, fovea, lucidum, porphyrins, organelles, glomeruli, neurone, proteins, morphogen, motor neuron, fluorescent dye, cavefish, oligodendrocytes, chromophore, forebrain, motoneurons, cells, planaria, superior colliculus, retinitis pigmentosa, glial, electrical conduction, neurites, substantia nigra, midbrain, spectrin, optic nerve, choroid, cilia, epicardium, mesoderm, planarians, sensory neuron, astrocytes, neuromuscular junction, melanocyte, achromatopsia, epithelial tissue, myelin, lymphatics, exocytosis, mitochondria, mesenchyme, stroma, fluorescence, nuclei, ciliary, crystalline lens, myelination, neurite, receptors, cochlea, peroxisome, ovules, cortex, pineal, auditory cortex, myelin sheath, enzyme, calmodulin, suppressor gene, binocular vision, testis, auxin, iridescence, luciferase, hindbrain, bistable, epithelial cell, tubules, fibroblasts, centrioles, dendrites, centromeres, epithelia, proteolysis, spermatogenesis, organogenesis, nucleolus, punctate, lymphocytes, acinar, choroid plexus, nephron, granulocytes, tissue, pineal gland, centrosomes, chromophores, myofibrils, nephrons, organs, afferent, loci, subunits, transporters, cytochromes, plastids, terminals, atoms, blastomeres, chromatophores, cortical, effectors, elements, exons