Chromosomal composition of the mouse strains used in this study based on precise chromosomal mapping. The RC strain CcS-11 contains a random set of ~12.5% genes from strain STS donor strain and 87.5% genes from strain BALB/c (background strain). Sex chromosomes are not shown in this figure (A). Survival of mice after s.c. inoculation of TBEV. Mice (n = 10 per group) were inoculated with 103 pfu of TBEV and observed for lethality (B). Survival of mice (BALB/c, n = 8; CcS-11, n = 9; STS, n = 7) after i.c. inoculation of 10 pfu of TBEV (C).