[Kinetoplast DNA of Crithidia oncopelti. Recognition of the principles of structural organization of minicircular DNA molecules].

The heterogeneity of the kinetoplast minicircular DNAs from Crithidia oncopelti was studied by electron microscopy and restriction analysis. The associate of kinetoplast DNA comprises five main classes of minicircles sizing 0.42, 0.51, 0.62, 0.78 and 0.83 microns. Examination of cleavage patterns revealed that each class of the minicircles is heterogeneous in base sequence, but there are restriction fragments of the same size common for all these classes. A model of structural arrangement of minicircles of Crithidia oncopelti was proposed. This model is based on the block structure of minicircular molecules. Each minicircle is composed of one variable block (V-block), 810 base pairs, and from 1 to 4 more conservative blocks (C-blocks) each containing 445 base pairs.