Circadian timekeeping in hamster mutants - PROJECT ABSTRACT Aberrant light exposure disrupts daily rhythms in humans and is linked to many diseases. This is a serious public health concern because light at night impacts up to 80% of Americans. Further, polymorphisms in circadian genes alter sleep and responses to light, which produces high personal and societal burdens. Despite many gains in the field, a major gap remains in understanding how changes in molecular clock function translate into phenotype and pathology. One obstacle is the common use of mouse models that lack systemic cues present in humans and other mammals (e.g., melatonin). The Syrian hamster is a melatonin- competent rodent with an impressive repertoire of circadian and photoperiodic responses to light. Having developed the first circadian reporter in a hamster model, here we will investigate circadian timekeeping at the central and systems-level in this informative species. Further, we will leverage well-characterized mutations present in the hamster that affect circadian clock function, photoentrainment, and physiology. This work will lay the essential foundations to use this animal model to gain a more holistic understanding circadian and photoperiodic processes that impact health.
