Biomaterial Database

Deoxyribonucleic acid hybridization analysis of the defective bacteriophage carried by strain 15 of Escherichia coli. 1971

L J Grady, and D B Cowie, and W P Campbell

Evidence from several laboratories indicates that strain 15 of Escherichia coli is lysogenic for a defective phage. When lysates from induced cultures were centrifuged in CsCl, three bands were obtained. In order of decreasing density, these bands contained tailless particles, complete phages, and a second band of complete phages, in a ratio of 65.7:28.6:5.7. Reassociation rate measurements were used to establish that the molecular weights of the deoxyribonucleic acid (DNA) species from the phages in the first two bands are similar. A smaller genome is postulated in the complete phages from the minor band. Hybridization experiments revealed extensive homology between the DNA species from all three phage bands, thus suggesting that the complete and tailless particles are not different at the genetic level. The DNA from each phage band was also shown to hybridize almost completely with DNA from either E. coli 15T(-) or a reportedly cured derivative of 15T(-). In contrast, only about 25% of each phage DNA was able to react with DNA from E. coli strains B and K-12 C-600.

UI	MeSH Term	Description	Entries
D008242	Lysogeny	The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.	Integration, Prophage,Prophage Integration,Integrations, Prophage,Prophage Integrations
D008937	Mitomycins	A group of methylazirinopyrroloindolediones obtained from certain Streptomyces strains. They are very toxic antibiotics used as ANTINEOPLASTIC AGENTS in some solid tumors. PORFIROMYCIN and MITOMYCIN are the most useful members of the group.
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
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
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
D002876	Chromosomes, Bacterial	Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.	Bacterial Chromosome,Bacterial Chromosomes,Chromosome, Bacterial
D003090	Coliphages	Viruses whose host is Escherichia coli.	Escherichia coli Phages,Coliphage,Escherichia coli Phage,Phage, Escherichia coli,Phages, Escherichia coli
D003673	Defective Viruses	Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.	Incomplete Viruses,Defective Hybrids,Defective Hybrid,Defective Virus,Hybrid, Defective,Hybrids, Defective,Incomplete Virus,Virus, Defective,Virus, Incomplete,Viruses, Defective,Viruses, Incomplete
D004267	DNA Viruses	Viruses whose nucleic acid is DNA.	DNA Virus,Virus, DNA,Viruses, DNA