Biomaterial Database

Temperature-dependent formation of dimers and oligomers of mitochondrial DNA in cells transformed by a thermosensitive mutant of Rous sarcoma virus. 1973

M M Nass

In chick-embryo fibroblasts infected by T5, a temperature-sensitive mutant of Schmidt-Ruppin Rous sarcoma virus, the level of catenated dimeric and oligomeric mitochondrial DNA is temperature-dependent and correlates with the phenotypic manifestation of transformation. At the permissive temperature (36 degrees ), where transformation is expressed, the 2- to 3-fold elevated level characteristic of cells transformed by the wild-type Rous sarcoma virus was observed, but at the nonpermissive temperature (41 degrees ), at which cells appear normal and behave normally, the oligomer level was characteristic of uninfected cells. Temperature shifts from 41 to 36 degrees and vice versa resulted in phenotypic reversion and reversals of the respective levels of multiple-length DNA. Cellular growth rates were not altered. Treatment of control cells with cycloheximide resulted in a 5-fold increase of oligomeric DNA, whereas exposure to 9-beta-D-arabinofuranosyladenine had little effect. With both inhibitors, nuclear but not mitochondrial DNA synthesis was inhibited. The possible relation of formation of oligomeric mitochondrial DNA to alterations in the mitochondrial membranes of transformed cells and to inhibition of protein synthesis in the cytoplasm is discussed.

UI	MeSH Term	Description	Entries
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
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D009705	Nucleosides	Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Nucleoside,Nucleoside Analog,Nucleoside Analogs,Analog, Nucleoside,Analogs, Nucleoside
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002471	Cell Transformation, Neoplastic	Cell changes manifested by escape from control mechanisms, increased growth potential, alterations in the cell surface, karyotypic abnormalities, morphological and biochemical deviations from the norm, and other attributes conferring the ability to invade, metastasize, and kill.	Neoplastic Transformation, Cell,Neoplastic Cell Transformation,Transformation, Neoplastic Cell,Tumorigenic Transformation,Cell Neoplastic Transformation,Cell Neoplastic Transformations,Cell Transformations, Neoplastic,Neoplastic Cell Transformations,Neoplastic Transformations, Cell,Transformation, Cell Neoplastic,Transformation, Tumorigenic,Transformations, Cell Neoplastic,Transformations, Neoplastic Cell,Transformations, Tumorigenic,Tumorigenic Transformations
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D003513	Cycloheximide	Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.	Actidione,Cicloheximide
D004272	DNA, Mitochondrial	Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.	Mitochondrial DNA,mtDNA
D004273	DNA, Neoplasm	DNA present in neoplastic tissue.	Neoplasm DNA