Cell-to-cell communication in differentiation of mycelial fungi.

Electric and ionic interactions in fungal hyphae under controlled environmental conditions were characterized. The interactions were shown to be local and genetically determined. The possibility of their regulation by the blue-violet light and the membrane potential gradient between the adjacent cells was demonstrated. Septal pores providing the intercellular communication in fungi share common functional features with animal gap junctions, plant plasmodesmata, and microplasmodesmata of cyanobacteria. Integration of cells in a structurally and functionally heterogeneous ensemble takes place via local intercellular interactions due to a nonuniform distribution of ionic pumps and secondary transport systems in the apical and proximal hyphal cells. Cell differentiation during the hyphal growth results from the redistribution of functions in apical cells populations. The loss of polarity by growing intercalary hyphal fragments and equalization of ionic gradients during the regeneration of mechanically damaged intrahyphal fragments may indicate the existence of different growth mechanisms in the mycelium. Synchronization of functions of individual hyphal compartments exhibiting considerable electrophysiological heterogeneity takes place during the blue-light signal transduction, which triggers the hyphal differentiation processes.