Electron Microscopy of Chick Fibroblasts Infected by Defective Rous Sarcoma Virus and Its Helper

Although the natural host of the Rous sarcoma virus (RSV) is the chicken, many strains of the virus have induced tumors in various mammals. Recently, a New World monkey, the marmoset (Saquinus sp.), was added to the list of animals susceptible to RSV oncogenesis (1). This report deals with a unique membranous cytoplasmic structure found in cells from two intracerebral and four subcutaneous tumors which developed following neonatal inoculation with the Schmidt-Ruppin strain of RSV.

Section: Discussionmentioning

confidence: 54%

Section: Discussionmentioning

confidence: 60%

Unique Cytoplasmic Membranes in Rous Sarcoma Virus-Induced Tumors of a Subhuman Primate

Smith

Deinhardt

1968

“…The morphology of the cultured chick embryo fibroblasts has been described by other investigators (51,52) . However, these observations were related to ultrastructural changes associated with viral infections .…”

Section: The Morphology Of Cells In Thin Sectionsmentioning

confidence: 86%

The Distribution, Ultrastructure, and Chemistry of Microfilaments in Cultured Chick Embryo Fibroblasts

Perdue

1973

132

The distribution, ultrastructure, and chemistry of microfilaments in cultured chick embryo fibroblasts were studied by thin sectioning of flat-embedded untreated and glycerol-extracted cells, histochemical and immunological electron microscopic procedures, and the negative staining of cells cultured on electron microscopic grids . In these cultured cells, the microfilaments are arranged into thick bundles that are disposed longitudinally and in looser arrangements in the fusiform-shaped cells . In the latter case, they are concentrated along the margins of the flattened cell, on the dorsal surface, and particularly at the ends of the cell and its ventral surface, where contact is made with the plastic dish or with other cells . Extracellular filaments, presumably originating from within the cell, are found at these points of contact . The microfilaments are composed in part of an actin-like protein .These filaments are between 70 and 90 A in diameter, they are stable in 50 0]0 glycerol, they have an endogenous ATPase (myosin-like?) associated with them, they bind rabbit muscle heavy meromyosin, and they specifically bind antibody directed against isolated actin-like protein . In the cultured chick embryo fibroblasts, the microfilaments are essential for the establishment and maintenance of form, and they are probably critical elements for adhesion and motility . The microfilaments might also serve as stabilizers of intramembranous particle fluidity .

“…AL have been reported from a wide variety of animal cell types including germ cells and embryonic cells, adult somatic cells, and some tumor and cancer cells, and have been reviewed extensively (10,33) and more briefly (4,11). An increase in the amount of AL in virus-infected animal cells, both in vivo and in vitro, has been documented (1,12,13,20,21,22,24). AL have also been induced to form in cells treated with a variety of chemical stimuli (2,15,16).…”

mentioning

confidence: 99%

Annulate lamellae in phloem cells of virus-infected Sonchus plants.

Steinkamp¹,

Hoefert²

1977

The occurrence of annulate lamellae (AL) in differentiating phloem of Sonchus oleraceus (Compositae) singly infected with sowthistle yellow vein virus (SYVV) and doubly infected with a combination of SYVV and beet yellow stunt virus is documented by electron microscopy. Cell types in which AL were found were immature sieve elements and phloem parenchyma cells. AL were found only in cells that also contained SYVV particles although a direct association between the virus and AL was not apparent. The substructure of the AL and the relationships between the AL and the nuclear envelope and endoplasmic reticulum are similar to those reported in other descriptions of this organelle in the literature. This report appears to be the first one concerning the association of AL with a plant virus disease.Annulate lameilae (AL) are subceilular organelles that are structurally similar to both the nuclear envelope and the endoplasmic reticulum (ER). AL cisternae, containing definitive pore complexes similar to those of the nuclear envelope, are found either singly or in parallel stacks, usually in the perinuclear cytoplasm but sometimes elsewhere in the cytoplasm or within the nucleus itself. AL have been reported from a wide variety of animal cell types including germ cells and embryonic cells, adult somatic cells, and some tumor and cancer cells, and have been reviewed extensively (10, 33) and more briefly (4, 11). An increase in the amount of AL in virus-infected animal cells, both in vivo and in vitro, has been documented (1,12,13,20,21,22,24). AL have also been induced to form in cells treated with a variety of chemical stimuli (2,15,16).Only a few reports of AL in plant cells have been published. Kessel (10), in the addendum of his review, states that Skvarla saw AL in developing pollen of Canna, but these observations were not published. The earliest documented report of AL in plant cells appears to be that of Gianordoli (8), who described their structure, origin, and formation in the peripheral cytoplasm of the central cell of the gymnosperm Sciadopitys verticillata