Cryptochromes retinal

Cryptochromes and inner retinal non-visual irradiance detection... 

The decreased behavioural photoresponsiveness in cryptochrome-mutant mice is somewhat difficult to interpret since these mice also lack free-running circadian rhythms. Therefore, one is measuring masking, not circadian responses. Although masking is also preserved in retinal-degenerate animals (Mrosovsky et al 2000), the neural and molecular mechanisms of masking are not as well understood as those of circadian rhythms. 

Retinal-degenerate mice lacking cryptochromes show markedly decreased behavioural photoresponses and pupillary responses, while non-degenerate mice lacking cryptochromes show intact photic signalling... 

Mice lacking cryptochromes and ocular retinal show no photic induction of immediate early genes in the SCN... 

Albus H, Bonnefont X, Chaves I et al 2002 Cryptochrome-deficient mice lack circadian electrical activity in the suprachiasmatic nuclei. Curr Biol 12 1130—1133 Balsalobre A, Brown SA, Marcacci L et al 2000 Resetting of circadian time in peripheral tissues by glucocorticoid signaling. Science 289 2344—2347 Berson DM, Dunn FA, Takao M 2002 Phototransduction by retinal ganghon cells that set the circadian clock. Science 295 1070—1073... 

Fig. 3. Examples of natural photoantenna chromophores (2) 5,10-methenyltetrahydrofolate (MTHF), a blue light photoreceptor pigment present in photolyase and some cryptochromes (3) Pheophytin a, the primary electron acceptor in cyanobacterial oxygenic photosynthesis. (4) 11-cis-retinal, which is involved as sensory photoreceptor component in the opsin-based visual process of animals and (5) the p-hydroxy-benzylidene-imidazolinone chromophore (HBDI) of the green fluorescent protein from bioluminescent marine species.

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