Ultrastructural Localization of Cytomegalovirus DNA Synthesis in Infected Guinea-pig Cells

Abstract

SUMMARYUsing electron microscopic autoradiographic techniques, the uptake of [methyl-3H]thymidine into uninfected and guinea-pig cytomegalovirus (GPCMV)-infected guinea-pig embryo (GPE) fibroblast cells was investigated. In GPCMV-infected GPE cells, [methyl-3H]thymidine uptake into cellular DNA was inhibited prior to the onset of virus DNA synthesis as well as during the entire period of virus replication. Virus DNA synthesis increased slowly during the period of active virus replication, which usually lasted from 18 to 48 h post-infection. Only the electron-dense amorphous matrices and fibrillar structures in the nuclear inclusions were associated with the tritiated labels and thus contained virus DNA.

Replication of herpes-like viruses in haemocytes of adult flat oysters Ostrea angasi:an ultrastructural study

“…However, the ovoid fine granular inclusion does not closely resemble these components, and capsids have not been reported in close association with nucleolar components. The dark strands and rod-like configurations near the centre of nuclei resemble the early intranuclear inclusion (Cavallo et al 1981), and the bundles of electron-dense filaments (Fong 1982), of early CMV infections. The early intranuclear inclusion appears to develop into the coarse granular matrix (Cavallo et al 1981), seen here in March samples.…”

“…The early intranuclear inclusion appears to develop into the coarse granular matrix (Cavallo et al 1981), seen here in March samples. The bundles of electron-dense filaments also probably develop into the coarse granular matrix, as both are the site of viral DNA production (Fong 1982, Wolber et al 1988, in which case the early nuclear inclusion (Cavallo et al 1981) and bundles of electron-dense filaments (Fong 1982) are probably homologous. The strands and rodlike configurations of dark material seen here are probably also homologous.…”

Monoclonal Antibodies to Guinea-pig Cytomegalovirus: An Immunoelectron Microscopic Study

“…Ultrastructurally, nuclear inclusions in GPCMV-infected cells consist of several components such as electron-dense amorphous matrices, tubular structures, bundles of electron-dense fibrils and electron-dense granules (Fong et al, 1979;Fong, 1982). It might be interesting, from the standpoint of viral morphogenesis, to establish which components of the nuclear inclusion react with antibodies to the 50K polypeptide.…”

“…Considering the apparent increase in size of the structures as detected by indirect immunological reactions, the filamentous structures may correspond to the 10 nm fibrils of the inclusions. Fong (1982) demonstrated by electron microscopic autoradiography that virus DNA is present in both the electron-dense amorphous matrices and the fibrils.…”

“…The ultrastructural development of GPCMV-infected cells has been reported by Middelkamp et al (1967), Patrizi et al (1967), Fong et al (1979Fong et al ( , 1980 and Fong (1982). The nuclear inclusions in GPCMV-infected cells consist of a variable number of associated subunits: nucleocapsids, tubular structures, electron-dense fibrils and amorphous matrices (Fong et al, 1979(Fong et al, , 1980.…”