Light reception in Neurospora crassa as a model for studying signal transduction: a second, novel input pathway

• Applicant: Professorin Martha Merrow, Ph.D.
• Subject Area: Cell Biology
• Term: from 2003 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5404431

Previously, a single light input pathway was indicated in Neurospora, with photoreception by one or both of the WHITE COLLAR proteins. However, a bifurcated light input pathway can be demonstrated physiologically, and the Neurospora genome sequence indicates additional photoreceptor candidates. We have identifield a novel, 'alternative' light input pathway. The pathway that was previouly studied controls carotenogenesis. The alternative light input pathway regulates conidiaton, specifically with respect to 24 h light/dark cyles that might be involved in circadian or diurnal timing. The purpose of this proposal is to characterize this novel pathway genetically and physiologically. Experiments include use of reporter gene constructs in order to track light input by the alternative pathway, and a full description of the signature features of this heretofore undescribed light input system. Photoreception by both light pathways will be charactized by action spectra. Using this information, genetic strategies will be used to identify the novel photoreceptor molecule. In addition to serving as a simple model system to understand more complex light reception mechanisms, the description of these sensory input pathways is relevant to mechanisms used by numerous singal transduction pathways.

• DFG Programme: Research Grants