Structure and Development of Viruses as Observed in the Electron Microscope

Abstract

Western equine encephalomyelitis (WEE) virus is 40 to 55 m/z in diameter (1) and apparently contains nucleic acid of the ribose type (2, 3). Although electron microscopic examination of whole mounts of tissue cultures infected with a closely related agent (Eastern equine encephalomyelitis virus) has shown viral particles both within and on the surface of cells (4,5), no studies employing thin sections have been previously reported. The purpose of this communication is to illustrate and describe the manner in which WEE virus appears to differentiate within, and gain egress from, infected tissue culture cells as revealed in thin sections by the electron microscope. Similarities in development or release among WEE virus, influenza virus, herpes simplex virus, the virus associated with erythroblastosis of chickens, Rous sarcoma virus and a mouse mammary tumor agent will be discussed. Stable human amnionic cells:A stable line of human anauionic epithelium was kindly supplied by Dr. Katherine Sprnnt. Replicate cultures were prepared in Leighton tubes without coverslip% using Eagle's basal medium with 10 per cent horse serum. The cultures were inocu-* These studies were aided

The Application of Ferritin-Conjugated Antibody to Electron Microscopic Studies of Influenza Virus in Infected Cells

“…Although this phenomenon had been suspected in previous studies, it was hitherto not possible to obtain a sufficient number of serial sections to prove that the presumed vacuole did not represent a cross-section through an infolding of the undulant surface of the cell; but the absence of ferritin within the vacuole described herein reveals that it does not communicate with the extracellular space. The ability of influenza virus to differentiate at membranes both on the cellular surface and within the cytoplasm appears to be shared by Western equine encephalomyelitis virus (15). It should be emphasized, however, that in contrast to Western equine encephalomyelitis virus the occurrence of influenza virus within intracellular vacuoles is the exception rather than the rule.…”

Sensitivity of bluetongue virus to lipid solvents, trypsin and pH changes and its serological relationship to arboviruses

“…The sensitivity of arboviruses to lipid solvents and the finding that RNA can be extracted from these viruses only by the 'hot phenol' method (Wecker, 1959) suggest that lipids are contained in an envelope which protects the RNA. Electron micrographs of WEE virus (Morgan, Howe & Rose, 1961) and Sindbis virus (Mussgay & Rott, 1964) have also indicated the existence of such an envelope. Myxoviruses and viruses belonging to the herpes group, which also are sensitive to lipid solvents, are all known to possess an envelope.…”

Phylogeny and primary structure analysis of fiber shafts of all human adenovirus types for rational design of adenoviral gene-therapy vectors

“…The virus enters host cells by a process termed receptormediated endocytosis (Maxfield & McGraw, 2004) via clathrin-coated pits using dynamin-mediated endocytosis Morgan et al, 1969;Nemerow & Stewart, 1999;Wang et al, 1998). Cell entry is followed by an interaction with cytosolic molecular motors, which drive the capsid along microtubules (Mabit et al, 2002;Suomalainen et al, 2001) through the microtubuleorganizing centre to the nucleus (Kelkar et al, 2004).…”