[DNA-dependent RNA polymerases from loach embryos. General characteristics of cell-free RNA-synthesizing systems of different complexities].

The RNA-polymerase activity was solubilized and partially purified from embryo homogenates and from the nuclei and cytoplasm of developing loach (Misgurnus fossilis) embryos. In all preparations studied the two main forms of RNA-polymerase, i. e. form I responsible for rRNA synthesis and form II responsible for DNA-like RNA synthesis, were detected. The effects of various ions, ionic strength and alpha-amanitine on the activities of these two forms of RNA-polymerases in cell-free systems of different complexities were studied. The conditions for differential manifestation of activities of forms I and II in isolated embryo nuclei were found. It was demonstrated that the alpha-amanitine test is not a universal one for determination of RNA-polymerase I and II ratios in non-purified enzyme systems.