[Chromatin morphology and cytokinesis in pleurocapsalean cyanobacteria].

By means of differential interference contrast (DIC) and fluorescence microscopy, chromatin morphology and cytokinesis have been described in the cyanobacterium Pleurocapsa sp. CALU 1126 capable of multiple fission (multiple reproduction of the mother cell, the macrocyte, with formation of unique reproductive cells, the baeocytes). Two kinds of chromatin behavior have been revealed in the cell cycle: 1) the formation of numerous chromatin areas before their compartmentalization by multiple fission; 2) chromatin condensation in the phase of binary fission, and chromatin decondensation in growth period. The cytokinetic essence of multiple fission has been shown to consist of successive binary fissions of the macrocyte, while in between the mother cells (pre-baeocytes) do not grow.