Electron optic aspects of a murine cytomegalovirus strain grown in R1 mouse kidney cell cultures.

The electron microscopic study of a mouse kidney cell line (R1) infected with a murine cytomegalovirus strain isolated from a micromammal captured in the area of endemic Balkan nephropathy demonstrated the presence of multiple types of virus particles, in different phases of replication. Nucleocapsids with a partially or almost totally empty centre were predominant. The small number of particles with an electron-dense core and double envelope points to a low yield of mature infectant particles.