Biomaterial Database

Biochemical properties of endogenous rat C-type viruses. 1977

J Svec, and R Michalides

The cellular restriction to persistence of inducible C-type viruses of at least two rat strains can be overcome in actively in vitro replicating and/or spontaneously transforming rat embryo cells. Both, SD-RaLV and W-RaLV particles are morphologically and biochemically related to known oncorna viruses: They are of C-type, have an identical buoyant density of 1.15 g/cm3 in sucrose gradients and contain high-molecular-weight RNA. The RaLV-associated DNA polymerase exhibit both exogenous (polynucleotide-templated) and endogenous (viral RNA-templated) reactivity. The enzyme strongly preferred Mn++ over Mg++ ions (Mg++/Mn++ ratio of 0.04 to 0.07), with maximum reactivity at 0.1 mM MnCl2 concentration. The molecular hybridization experiments revealed the endogenous nature of the SD-RaLV and the W-RaLV. From the competition hybridization assay the number of proviral sequences could be calculated to be 84 per haploid cell genome. The role of endogenous rat viruses in the "spontaneous" in vitro transformation is discussed.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
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
D004259	DNA-Directed DNA Polymerase	DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair.	DNA Polymerase,DNA Polymerases,DNA-Dependent DNA Polymerases,DNA Polymerase N3,DNA Dependent DNA Polymerases,DNA Directed DNA Polymerase,DNA Polymerase, DNA-Directed,DNA Polymerases, DNA-Dependent,Polymerase N3, DNA,Polymerase, DNA,Polymerase, DNA-Directed DNA,Polymerases, DNA,Polymerases, DNA-Dependent DNA
D005814	Genes, Viral	The functional hereditary units of VIRUSES.	Viral Genes,Gene, Viral,Viral Gene
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
D001358	Avian Sarcoma Viruses	Group of alpharetroviruses (ALPHARETROVIRUS) producing sarcomata and other tumors in chickens and other fowl and also in pigeons, ducks, and RATS.	Avian Sarcoma Virus B77,Chicken Sarcoma Virus B77,Chicken Tumor 1 Virus,Fujinami sarcoma virus,Sarcoma Viruses, Avian,Avian Sarcoma Virus,Fujinami sarcoma viruses,Sarcoma Virus, Avian,Virus, Avian Sarcoma,Viruses, Avian Sarcoma,sarcoma virus, Fujinami,virus, Fujinami sarcoma,viruses, Fujinami sarcoma
D012190	Retroviridae	Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).	Leukemogenic Viruses,Leukoviruses,Oncornaviruses,Oncovirinae,Oncoviruses,Oncoviruses, Type C,RNA Tumor Viruses,Retroviruses,Type C Oncoviruses,C Oncovirus, Type,C Oncoviruses, Type,Leukemogenic Virus,Leukovirus,Oncornavirus,Oncovirus,Oncovirus, Type C,RNA Tumor Virus,Retrovirus,Tumor Virus, RNA,Tumor Viruses, RNA,Type C Oncovirus,Virus, Leukemogenic,Virus, RNA Tumor,Viruses, Leukemogenic,Viruses, RNA Tumor
D012367	RNA, Viral	Ribonucleic acid that makes up the genetic material of viruses.	Viral RNA