Support is requested for a preparative ultracentrifuge, liquid scintillation counter and an, autoclave. This equipment is urgently needed for biochemical studies of photoresponses in two eukaryotic microorganisms, the fungus Phycomyces blakesleeanus and the alga Chlamydomonas reinhardtii. In Phycomyces, blue light controls several response, including phototropism, light growth responses, carotene synthesis, and sporangiophore development. The blue-light photoreceptors in Phycomyces and in many other plants and fungi remain to be identified. The availablity of well characterized mutants, provides a strategy for biochemical isolation of photoreceptors and other molecules involved in photosensory transduction processes. In Chlamydomonas, phototaxis and carotene synthesis employ a rhodopsin photoreceptor. This rhodopsin, however, has yet to be purified in sufficient quantity for spectroscopic analysis. The increasing level of biochemistry work in the two biophysics research groups requires that appropriate equipment be available within the physics building, instead of only in the biology building across campus. The ultracentrifuge is required for cell fractionation, in particular membrane fractionation. The liquid scintillation counter will be used for receptor binding studies and for tracing signaling pathways using radioactively labeled probes. The autoclave will be used for sterilization of rowth media and apparatus.
