Cryptochromes mutants

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. 

B osbash When we saw cryptochrome disappear within a few minutes of light exposure, we spent some time trying to make mutants to change the action spectrum. We failed. 

A second system contributing to light entrainment was elucidated by the identification of cryptochrome, a clock component. Characterization of a fly mutant, showed that they also take a longer time to re-entrain their... 

Van Gelder The Bmal mutant mice are hypoactive, but it is unclear whether this is secondary to skeletal problems. You can imagine that the signal would be pegged differently depending on where the clock is frozen in, say, a cryptochrome double mutant versus a Bmalmutant. 

Recently, a TREPR study of light-induced paramagnetic intermediates from wild-type cryptochrome DASH of the frog X. laevis was presented and the results were compared with those from a mutant protein (W324F) lacking the terminal tryptophan residue of the conserved putative electron-transfer chain [109] see Fig. 8. 

The Phytochrome Gene Family in Tomato Cryptochromes Family of Tomato Photomorphogenic Mutants of Tomato Photomorphogenic Responses in Different Phases... 

Weller, J.L. et al. Genetic dissection of blue-light sensing in tomato using mutants deficient in cryptochrome 1 and phytochromes A, B1 and B2, Plant /., 25, 427, 2001. 

FIGURE 138.3 Wheel-running actograms of cryptochrome and rd mutants. Animals were entrained to 12 h light 12 h dark cycles, followed by constant darkness at Day 19. Numbers on the Y axis indicate days numbers on the X axis indicate time of day. White bars indicate light, black bars indicate dark (top). (From Selby, C.P., et al., Proc. NatL Acad. Sci. USA, 97, 14697, 2000. With permission.)... 

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