Wild mouse retrovirus-induced neurogenic paralysis in laboratory mice. I. Virus replication and expression in central nervous system.

Ecotropic wild mouse retrovirus (1504 M)-induced neurogenic paralytic disease has been studied in inbred strains of mice. The major criterion for the successful transmission of the disease in the laboratory strains of mice is inoculation of high titer ecotropic virus in FV-1n strains of mice at newborn stage (less than or equal to 1 day old), Hybridization studies using 1504 M viral cDNA as probe indicate that in nonparalyzed mice, the inoculated virus replicates primarily in spleen tissue, whereas virus replication is evident in both spleen and central nervous system (CNS) tissue of paralyzed mice. Our studies on virus gene expression indicate that both viral gag gene product p30 and env gene product gp70 are expressed in brain, spinal cord and spleen tissues of paralyzed mice. Together, these results indicate that inoculation of neurotropic wild mouse virus into FV-1n strains of newborn laboratory mice is necessary for the establishment of infection in CNS tissue leading to virus replication and expression and resulting in the paralytic disease.