THE FINE STRUCTURE OF CYTOPLASMIC INCLUSIONS AND VIRUS PARTICLES OF BOVINE PAPULAR STOMATITIS

The fine structures of cytoplasmic inclusions and VirUS particles of bovine papular stomatitis (B. P. S.) of one case were described. Two types of cytoplasmic inclusions, such as basophilic and eosinophilic inclusions, were observed in the epithelial cells. The former inclusions consisted of viroplasm and aggregates of a large number of virus particles which showed various developmental stages. The latter inclusions showed no evidence of virus particles and were subdivided into electron pale granular and highly opaque matrixes. In the viroplasm, granular amorphous or core-like electron opaque structures (immature forms of virus particles) were enclosed by a shell which consisted of a unit membrane covered with a dense layer formed by subunits. The granular structures appeared to develop into a mature virus particle inside of a shell and finally the shell seemed to disappear