Development of dengue virus type 4 in BHK21 cells.

The development of dengue type 4 virus in BHK21 and Vero cells was observed by electron microscopy. In BHK21 cells, completed virions appeared in vacuoles after marked vacuolization of the cytoplasm. Budding of dengue virions from internal membranous structures was observed in some of these vacuoles. A new type of vesicles with a marginal, rosary-like arrangement of particles was observed associated with masses of electron-dense particles. These vesicles were suggested to be related to virus production and named "rosary bodies".