Carotenoid synthesis and phytoene synthase activity during mating of Blakeslea trispora

► Mating of wild type and mutants for high carotene synthesis. ► Correlation of in vitro incorporation of geranylgeranyl pyrophosphate. ► Levels of phytoene synthase correspond to the degree of carotenogenesis. ► Post-translational cleavage of the phytoene synthase/lycopene cylase fusion protein. ► Immuno detection of individual domains after sub-cellular fractionation.