IN VITRO INTERACTION OF MOUSE HEPATITIS VIRUS AND MACROPHAGES FROM GENETICALLY RESISTANT MICE : II. BIOLOGICAL CHARACTERIZATION OF A VARIANT VIRUS MHV(C(3)H) ISOLATED FROM STOCKS OF MHV(PRI)

Shif, Ilan; Bang, Frederik B.

The genetics of RNA viruses are at present poorly understood. Among animal viruses the outstanding work on influenza initiated by Hirst (12) has indicated that a number of complex interactions occur whereby this virus, which has many affinities for the nucleus of the host cell, may undergo genetic recombination and may also produce a number of differing variants when large amounts of virus are inoculated on cells. In favor of a host-dependent step in the emergence of the variant MHV(C~H) is the fact that the variant appeared much more frequently in C~H cells which remained continually exposed to air than it did in C~H cells which were covered by an agar overlay. Subsequent unpublished work on this same system by Lavelle et al. has demonstrated that the environment of the C~H cultures has a marked effect on the susceptibility of the resistant C,~H cells.