Circadian rhythms in filamentous fungi

摘要

This review focuses upon circadian rhythmicity in the fungi; in particular circadian rhythmicity in one of the best-studied model systems, the Neurospora clock. Consideration will also be given to the limited number of true circadian rhythms that have been detected in other filamentous fungi. Many fungi display non-circadian rhythms (Ingold, 1971; Lysek, 1978, 1984), which are not discussed in detail. Suffice to say that the output rhythms of most fungi probably reflect direct changes in the environment, triggering immediate developmental or physiological responses. Reactions to light are the most prevalent, although tempera-ture also causes rhythmicity. Non-circadian rhythms may also arise from self-sustaining metabolic cycles. Examples of the latter may include the formation of concentric zones or archimedean spirals of conidia by Nectria cinnabarina (Bourret et al., 1969), the sporulation of Leptosphaeria controlled by oscillations in the asparagine–pyruvate path-way (Jerebzoff & Jerebzoff-Quintin, 1982) and the 'hormonal' triggering of hyphal growth rhythms in Ascobolus immersus and Podospora anserina (Chevaugeon & Nguyen Van, 1969).