Influence of tick-borne encephalitis and West Nile viruses on the chromosomes of pig kidney cells.

Changes of the mitotic index (MI) were studied in pig kidney (PS) cells infected either with tick-borne encephalitis (TBE) virus strains Hypr and Ir-32, or with West Nile (WN) virus prototype strain, strains K-99 and E-13. The cell division was arrested by the infection (metaphase barrier). The effect of TBE virus strains was manifested by the appearance of lagging chromosomes while the action of WN virus strains by colchicine--like metaphases. The prototype TBE virus strain Hypr affected the chromosomes and mitotic apparatus of PS cells less markedly than did the freshly isolated Ir-32 strain.