Detection and response of the Neurospora crassa circadian clock to light and temperature

Circadian clocks are molecular timekeepers that provide organisms with a means to predict and prepare for environmental change. The filamentous fungus Neurospora crassa has provided an excellent model system in which the underlying molecular basis of circadian clocks has been elucidated. In Neurospora, and in other eukaryotes, circadian rhythmicity emerges from a network of positive and negative feedback regulation acting on clock genes and proteins. An essential attribute of the clock is that it can detect and respond to the daily cycle of light and dark and temperature change and integrate these environmental time cues to give an accurate depiction of the external day. In Neurospora many of the molecules that sense the daily changes in light and temperature are known. In this review we describe Neurospora’s clock mechanism and how it is tuned to the real world by light and temperature.