HOST EFFECT AND STRAIN VARIABILITY OF TIC K-BORNE ENCEPHALITIS-VIRUS

The organism of arthropods and warm-blooded vertebrates as a habitat o f a virus determines the population genetic structure of tick-borne en cephalitis (TEE) virus strains. The pattern of hybridization by variab le zones of TEE genomes gradually changes in the course of intracerebr al passages of the virus in newborn white mice. During intracelomal pa ssages in Ixodidae hybridization alters as early as during the first p assage, both for variable and (in individual cases) conservative zones . Ixodid ticks should be regard ed as a mechanism maintaining the hete rogeneity of virus communities (strains and populations). Vertebrates and communities of dugout arthropods appear to be the mechanism reduci ng the effect of ecologic isolation of TEE strains.