Biomaterial Database

AtT20 pituitary tumour cells contain mouse mammary tumour virus and intracisternal A-type particles in addition to murine leukemia virus. 1985

J Tooze, and S Tooze, and H Haisma, and J Hilgers

By electron microscopy and immunocytochemistry we have examined the retroviruses endogenous to AtT20 D16V cells, a cloned line of murine pituitary tumour cells. In addition to the C-type retrovirus particles related to Rauscher murine leukemia virus (MuLV) previously reported to bud from these cells we observed cytoplasmic A-type particles and intracisternal A-type particles (IAP). In the cytoplasm the A-type particles occur in large clusters often associated with sheets of material with a fine structure resembling the shells of the particles. At the plasma membrane individual A-type particles bud to give rise to extracellular virions. The IAP are restricted to the rough endoplasmic reticulum (RER) into which they bud: they are not transported out of the RER to the Golgi apparatus and beyond. We describe a new monoclonal antibody (designated 83E7) which is specific for an epitope of the major core protein (MTVp27) of mouse mammary tumour virus (MMTV). Using immunogold labelling procedures we have specifically labelled both the A-type particles and the associated sheets of material with this antibody. We conclude that the A-type particles and the virions they give rise to are MMTV. The sheets of material must also at least in part be made up of the major core protein of MMTV or its precursor polypeptide. AtT20 cells, therefore, contain endogenous MuLV and MMTV as well as IAP.

UI	MeSH Term	Description	Entries
D007426	Genes, Intracisternal A-Particle	Genes of IAP elements (a family of retrovirus-like genetic elements) which code for virus-like particles (IAPs) found regularly in rodent early embryos. ("Intracisternal" refers to the cisternae of the endoplasmic reticulum.) Under certain circumstances, such as DNA hypomethylation they are transcribed. Their transcripts are found in a variety of neoplasms, including plasmacytomas, neuroblastoma, rhabdomyosarcomas, teratocarcinomas, and colon carcinomas.	IAP Elements,Intracisternal A-Particle Elements,Intracisternal A-Particle Genes,Gene, Intracisternal A Particle,A-Particle Element, Intracisternal,A-Particle Elements, Intracisternal,A-Particle Gene, Intracisternal,A-Particle Genes, Intracisternal,Element, IAP,Element, Intracisternal A-Particle,Elements, IAP,Elements, Intracisternal A-Particle,Gene, Intracisternal A-Particle,Genes, Intracisternal A Particle,IAP Element,Intracisternal A Particle Elements,Intracisternal A Particle Genes,Intracisternal A-Particle Element,Intracisternal A-Particle Gene
D008324	Mammary Tumor Virus, Mouse	The type species of BETARETROVIRUS commonly latent in mice. It causes mammary adenocarcinoma in a genetically susceptible strain of mice when the appropriate hormonal influences operate.	Bittner Virus,Mammary Cancer Virus,Mouse mammary tumor virus,Mammary Tumor Viruses, Mouse
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010911	Pituitary Neoplasms	Neoplasms which arise from or metastasize to the PITUITARY GLAND. The majority of pituitary neoplasms are adenomas, which are divided into non-secreting and secreting forms. Hormone producing forms are further classified by the type of hormone they secrete. Pituitary adenomas may also be characterized by their staining properties (see ADENOMA, BASOPHIL; ADENOMA, ACIDOPHIL; and ADENOMA, CHROMOPHOBE). Pituitary tumors may compress adjacent structures, including the HYPOTHALAMUS, several CRANIAL NERVES, and the OPTIC CHIASM. Chiasmal compression may result in bitemporal HEMIANOPSIA.	Pituitary Cancer,Cancer of Pituitary,Cancer of the Pituitary,Pituitary Adenoma,Pituitary Carcinoma,Pituitary Tumors,Adenoma, Pituitary,Adenomas, Pituitary,Cancer, Pituitary,Cancers, Pituitary,Carcinoma, Pituitary,Carcinomas, Pituitary,Neoplasm, Pituitary,Neoplasms, Pituitary,Pituitary Adenomas,Pituitary Cancers,Pituitary Carcinomas,Pituitary Neoplasm,Pituitary Tumor,Tumor, Pituitary,Tumors, Pituitary
D011519	Proto-Oncogenes	Normal cellular genes homologous to viral oncogenes. The products of proto-oncogenes are important regulators of biological processes and appear to be involved in the events that serve to maintain the ordered procession through the cell cycle. Proto-oncogenes have names of the form c-onc.	Proto-Oncogene,Proto Oncogene,Proto Oncogenes
D011925	Rauscher Virus	A strain of MURINE LEUKEMIA VIRUS associated with mouse tumors similar to those caused by the FRIEND MURINE LEUKEMIA VIRUS. It is a replication-competent murine leukemia virus. It can act as a helper virus when complexing with a defective transforming component, RAUSCHER SPLEEN FOCUS-FORMING VIRUS.	Rauscher leukemia virus,Rauscher leukemia viruses,Virus, Rauscher,leukemia viruses, Rauscher
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003034	Coated Pits, Cell-Membrane	Specialized regions of the cell membrane composed of pits coated with a bristle covering made of the protein CLATHRIN. These pits are the entry route for macromolecules bound by cell surface receptors. The pits are then internalized into the cytoplasm to form the COATED VESICLES.	Bristle-Coated Pits,Cell-Membrane Coated Pits,Bristle Coated Pits,Bristle-Coated Pit,Cell Membrane Coated Pits,Cell-Membrane Coated Pit,Coated Pit, Cell-Membrane,Coated Pits, Cell Membrane,Pit, Bristle-Coated,Pit, Cell-Membrane Coated,Pits, Bristle-Coated,Pits, Cell-Membrane Coated
D005455	Fluorescent Antibody Technique	Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.	Antinuclear Antibody Test, Fluorescent,Coon's Technique,Fluorescent Antinuclear Antibody Test,Fluorescent Protein Tracing,Immunofluorescence Technique,Coon's Technic,Fluorescent Antibody Technic,Immunofluorescence,Immunofluorescence Technic,Antibody Technic, Fluorescent,Antibody Technics, Fluorescent,Antibody Technique, Fluorescent,Antibody Techniques, Fluorescent,Coon Technic,Coon Technique,Coons Technic,Coons Technique,Fluorescent Antibody Technics,Fluorescent Antibody Techniques,Fluorescent Protein Tracings,Immunofluorescence Technics,Immunofluorescence Techniques,Protein Tracing, Fluorescent,Protein Tracings, Fluorescent,Technic, Coon's,Technic, Fluorescent Antibody,Technic, Immunofluorescence,Technics, Fluorescent Antibody,Technics, Immunofluorescence,Technique, Coon's,Technique, Fluorescent Antibody,Technique, Immunofluorescence,Techniques, Fluorescent Antibody,Techniques, Immunofluorescence,Tracing, Fluorescent Protein,Tracings, Fluorescent Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia