Pigment mutations associated with altered circadian rhythms in mice.

Mammalian albinism is known to alter neural pathways, reduce retinal pigment, and affect diverse behaviors. Mammalian circadian rhythms have been shown to depend on visual pathways, respond to light intensity and regulate many behaviors. Here we show that mice homozygous for the recessive albino or pinkeye-dilute mutations display shorter circadian rhythms than pigmented controls. We conclude that these pigment loci, or closely linked loci, influence the expression of circadian rhythms in mice.