INTERCELLULAR INTERACTIONS IN DIFFERENTIA TION OF MYCELIAL FUNGI

Electric and ionic interactions in fungal hyphae under controlled envi ronmental conditions were characterized. They were shown to be local a nd genetically determined. The possibility of their regulation by blue -violet light and the membrane potential gradient between the adjacent cells has been demonstrated. Septal pores providing the intercellular communication in fungi share common functional features with animal g ap junctions, plant plasmadesmata, and microplasmadesmata of cyanobact eria. Integration of cells in a structurally and functionally heteroge nous ensemble takes place via local intercellular interactions due to a nonuniform distribution of ionic pumps and secondary transport syste ms in the apical and proximal hyphal cells. Cell differentiation durin g the hyphal growth results from the redistribution of functions in th e apical cell populations. The loss of polarity by growing intercalary hyphal fragments and equilization of ionic gradients during regenerat ion of mechanically damaged intrahyphal fragments may indicate the exi stence of different growth mechanisms in the mycelium. Synchronization of functions of individual hyphal compartments exhibiting considerabl e electrophysiological heterogeneity takes place during the blue-light signal transduction, which triggers the hyphal differentiation proces ses.