THE TAU MUTATION AFFECTS TEMPERATURE COMPENSATION OF HAMSTER RETINAL CIRCADIAN OSCILLATORS

NEURAL retinas of the golden hamster (Mesocricetus auratus) express ci rcadian rhythms of melatonin synthesis when cultured in constant darkn ess. Retinas from wild-type hamsters synthesize melatonin with a perio d close to 24 h, while retinas obtained from hamsters homozygous for t he circadian mutation tall, which shortens the free-running period of the circadian activity rhythm by 4 h, synthesize melatonin with a peri od close to 20 h. The retinal circadian oscillators of both wild-type and tall mutant hamsters are temperature compensated; however, tempera ture compensation is adversely affected by the mutation. (C) 1998 Rapi d Science Ltd.