INFORMATION-ENERGETIC MODULE AS THE FUNCT IONAL UNIT OF THE NEUROSPORA-CRASSA POLARIZED GROWTH

Growth features of Neurospora crassa mycelium have been studied. Cutti ng of the N. crassa hypha into 0.1-1-mm fragments completely arrested the growth of 0.1-0.3-mm apical fragments. Longer apical fragments con tinued to grow in the apical direction without any delay. The rate of the apical fragment elongation was higher than 4 mu m/min. The contras t to the apical fragments, the basal fragments began to grow after a t en-minute delay and in the opposite directions simultaneously. The elo ngation rate of 0.1-0.3-mm basal fragments was 1-3 mu m/min. The elong ation rates both of the basal and apical fragments increased steadily in the process of growth and were higher than 5 mu m/min for the fragm ents of 0.8 mm and longer. The branching patterns were also determined . The ratio of full hyphal length (including all branches) to the numb er of tips does not differ for the fragments possessing from 1 to 45 t ips. In our experiments this ratio (<<hyphal growth unit>>) was always lesser than the electrical cable space constance characterizing the N . crassa hyphae (0.7 mm). The combined analysis of the experimental da ta and theoretical considerations on the electric and energetic interc ellular coupling allow us to conclude that growing hyphal 0.6-0.8-mm f ragment is a functionally independent information-energetic module pos sessing all the components required for the polarized growth. The expe rimental model developed can be used for detailed studying the laws of the interactions between materials and driving forces during polarize d growth.