Photoresponses of Phycomyces. The sensory pathway of Phycomyces link the blue-light stimulus (left) with the responses (right): sporangiophore (fruiting body) growth, phototropism and photomecism; inhibition of microphore development; stimulation of macrophores development; stimulation of carotene biosynthesis. The flow of information is hindered by mutations at the genes given in italic or by lack of beta-carotene. Mutants were isolated for their deffective phototropism (mad), carotenogenesis (car), photocarotenogenesis (pic), and photoinhibition of microphorogenesis (pim). Details can be found in Corrochano and Cerdá-Olmedo, "Sex, light and carotenes: the development of Phycomyces". Trends in Genetics 8, 268-274 (1992).