cell wall, crosslinking, EDAC, homothallism, hyphal surface,
mucoralean fungi, sexual differentiation
Zygomycetes as well as many other fungi from different taxonomic groups develop sexual structures predominantly in the aerial mycelium. Interaction between complementary mating types requires communication via volatile substances as well as contact formation at the cell surface. In order to study the biochemical basis of contact formation, we developed a versatile and generally applicable biochemical tool, allowing targeted modification of surface components by covalent coupling to substances with known physical, chemical or enzymatic properties. After modification, the influence of these substances on sexual development is followed microscopically. The technique is based on controlled spraying of substances to developing hyphae under mild conditions that do not disturb the developmental program. In addition to simply covering hyphal surfaces, ligands can be coupled covalently with any substance, containing either amino- or carboxyl-groups, by carbodiimide (EDAC) mediated crosslinking. This technique does not inhibit fungal growth or development. In the experiments, stimulatory as well as inhibitory effects on sexual differentiation have been observed.