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Mayer L W - - 1974
Five of six independent gonococcal isolates have been found to harbor a plasmid pool of covalently closed-circular deoxyribonucleic acid about 2.4 x 10(6) daltons in size. The plasmid species were 0.5-mol fraction of guanine plus cytosine and comprised 6 to 8% of the total gonococcal deoxyribonucleic acid equivalent, to approximately ...
Deutch C E - - 1974
To clarify the relationship between thymineless death and thymineless mutagenesis, the induction of arginine revertants of Escherichia coli TAU-bar by thymine starvation was examined in physiological terms. Induced revertants were detectable both on minimal medium lacking arginine and minimal medium supplemented with 1 mug of arginine per ml. Substantial thymineless ...
Campbell J L - - 1974
Direct assay for deoxyribonucleic acid polymerase II in extracts has been used to screen recombinants for the polB allele in Hfr x F(-) crosses, F-ductants in episome transfer, and transductants in generalized transduction by phage P1. The polB gene is located at 2 min on the Escherichia coli linkage map; ...
Inselburg J - - 1974
Cells colicinogenic for the colicin plasmids E1 or E2 (Col E1 and Col E2, respectively) were selected for a loss of colicin production after infection with bacteriophage Mu. Extrachromosomal deoxyribonucleic acid that was larger than the original colicin plasmids was found in such cells. A small insertion mutant in Col ...
Hopper A K - - 1974
The time course of synthesis and breakdown of various macromolecules has been compared for sporulating (a/alpha) and nonsporulating (a/a and alpha/alpha) yeast cells transferred to potassium acetate sporulation medium. Both types of cells incorporate label into ribonucleic acid and protein. The gel electrophoresis patterns of proteins synthesized in sporulation medium ...
Hang Y D - - 1974
Geotrichum candidum completely neutralized the acid brine and reduced its biochemical oxygen demand (BOD) by 88%. Yield of dry mycelium was 62 g per 100 g of BOD utilized.
Durkacz B W - - 1974
Induction of colicins E1 and E2 in Escherichia coli occurs when plasmid synthesis has been inhibited either by nalidixic acid or by lack of deoxyribonucleic acid polymerase I. Moreover, colicin E1 and E2 synthesis induced by mitomycin C and exposure to chloramphenicol is not associated with a large increase in ...
Leech R W - - 1974
Within the developing nervous system, there is a complex relationship between the accumulation of sudanophilic lipids in glial cells and gestational and postnatal age. Sudanophilic lipids accumulate to a small degree as a stage of normal premyelin lipogenesis, but large amounts of such accumulations may be considered abnormal. The dividing ...
Kahn P L - - 1973
Plasmid deoxyribonucleic acid from Escherichia coli harboring either the V colicinogenic factor (Col V) or the derivative fertility factor (Fv), (a non-colicin-producing fertility factor derived from Col V) were separated by cesium chloride-ethidium bromide centrifugation and examined by electron microscopy. Results indicate a deletion of 11 mum of deoxyribonucleic acid ...
Weiner R M - - 1973
The relationship between chromosome replication and morphogenesis in the budding bacterium Hyphomicrobium neptunium has been investigated. Nalidixic acid was found to completely inhibit deoxyribonucleic acid synthesis, but not ribonucleic acid synthesis. The antibiotic was bacteriostatic to the organism for the initial 5 h of exposure; thereafter it was bacteriocidal. Observation ...
Stewart C R - - 1973
When bacteriophage SP02 infects a Bacillus subtilis culture during or shortly after transformation, the frequency of transformants among the resulting lysogens is greatly reduced relative to that in the uninfected culture. The effect can occur after the deoxyribonucleic acid has been taken up and covalently attached to recipient deoxyribonucleic acid.
Rosenkranz H S - - 1973
Hydroxyurea, a potent inhibitor of deoxyribonucleic acid synthesis, inhibits the development of trachoma agent when applied at a concentration of 5 x 10(-2) M. At a lower concentration, 5 x 10(-4) M, hydroxyurea permits the development of the trachoma inclusion bodies and initial bodies, but arrests the formation of elementary ...
Michaels C A - - 1973
The effect of the antibiotic nalidixic acid on macromolecular metabolism in the yeast Saccharomyces cerevisiae has been studied. It was found that, upon the addition of nalidixic acid to a logarithmically growing culture, there is a transient inhibition of total cell ribonucleic acid, deoxyribonucleic acid, and protein synthesis, after which ...
Pemberton J M - - 1973
Using a variety of techniques, it has been established that the sex factor FP2 has a density of 1.717 g/cm(3) (corresponding to a guanine plus cytosine [G + C] content of 58%) and a mean circular contour length of 28.5 +/- 0.6 mum (corresponding to a molecular weight of 59 ...
Brunovskis I - - 1973
Electron microscopy examination of phiII-H deoxyribonucleic acid heteroduplexes, together with polyacrylamide gel electrophoretic analyses of phage ribonucleic acid species and proteins labeled in phiII or H-infected cells, demonstrates that Pasteurella pestis phage H is nearly identical to coliphage phiII.
George D - - 1972
Ultraviolet irradiation of Escherichia coli polA(-) cells reduces their capacity to support the growth of T4 phage. There is no additional loss of capacity observed in pol tsA(-)recA(-) double mutants at the nonpermissive temperature. The reversion frequency of a T4 rII mutant after ultraviolet irradiation is not changed by the ...
Lee H H - - 1972
A proteinaceous substance was detected in the liver of several animal species that inhibited the multiplication of certain deoxyribonucleic acid, but not ribonucleic acid, viruses. Preliminary experiments suggested that its site of action was not extracellular. It did not inhibit virus by interfering with adsorption to cells. It was suggested ...
Ballesta J P - - 1972
By using the M-band technique we have shown that portions of the membranes of Bacillus megaterium and Escherichia coli vary in their affinity for magnesium-Sarkosyl crystals and in phospholipid composition. The portion to which deoxyribonucleic acid is attached comprises as little as 4% of the total cell membrane, has a ...
Ou J T - - 1972
By means of both electron microscopy and plaque assay techniques, 10(-3)m Zn(2+) has been shown to reduce the adsorption rate of male-specific filamentous deoxyribonucleic acid bacteriophages to the tips of F pili. In contrast, 10(-3)m Zn(2+) did not affect the adsorption of male-specific ribonucleic acid phages to the sides of ...
Messer W - - 1972
Three processes necessary for the initiation of deoxyribonucleic acid replication have been separated in time in synchronously growing Escherichia coli B/r. One can be inhibited with 2 mug of chloramphenicol per ml and occurs about 20 min prior to initiation. A second step, occurring 5 to 10 min prior to ...
Lee L F - - 1972
Leukocytes recovered from birds inoculated with an oncogenic strain of Marek's disease virus synthesized deoxyribonucleic acid in vitro at a rate 7.9 times that of leukocytes from normal birds or birds inoculated with the nononcogenic herpesvirus of turkeys. A close relationship was observed between the level of in vitro deoxyribonucleic ...
Lin F H - - 1972
Maedi virus contains a ribonucleic acid (RNA) which can be resolved into three major components, namely, 62S, 33S, and 13S, by sucrose gradient centrifugation. The presence of RNA- and deoxyribonucleic acid (DNA)-dependent DNA polymerase in virions of maedi virus was demonstrated. The enzyme product could be converted into acid-soluble form ...
Martini A - - 1972
The deoxyribonucleic acid base composition (percent guanine + cytosine [GC]) was determined for 29 strains, representing 18 species of the genus Kluyveromyces. It was concluded that on the basis of GC content (47.4%) and other properties K. veronae occupies an uncertain position in the genus Kluyveromyces. The GC content of ...
Dubnau D - - 1972
A series of sheared donor-recipient complex samples were prepared from a competent Bacillus subtilis culture which had been transformed by using (3)H, (2)H-labeled deoxyribonucleic acid. Measurement of the molecular weights and buoyant densities of these samples led to the following conclusions. (i) The average size of the single-stranded donor segment ...
Knovicka J - - 1972
Long-tailed azotophages of two different serological groups have deoxyribonucleic acid species whose densities correspond to a molar percentage of guanine plus cytosine of 52 to 53. Similar measurements on the short-tailed phages gave values of 56 to 57 moles percent. The azotophages include representatives of the three morphological types classified ...
LaMontagne J R - - 1972
Bacteriophage TSP-1 was isolated from soil in a search for phage which would form plaques on Bacillus subtilis W168 at 53 C. It forms clear plaques only at temperatures from 50 to 55 C. Approximately 95% of the free phage adsorb after 2 min at 53 C. The lytic cycle ...
Skyring G W - - 1972
Guanine plus cytosine (GC) contents of the deoxyribonucleic acids of Desulfovibrio and Desulfotomaculum have been used as a basis for classification. Some of these data have been incorrectly calculated, resulting in errors of as much as 5% GC. This situation has been corrected by a reanalysis of existing data and ...
Rana R S - - 1972
When heat-activated spores of Bacillus cereus T (thy(-)) were germinated and grown in medium containing (3)H-thymidine, a significant amount of radioactivity was incorporated into ribonucleic acid and deoxyribonucleic acid (DNA). A method was developed to restrict the incorporation of radioactivity from (3)H-thymidine into DNA only. This was accomplished by labeling ...
Ralston E - - 1972
Evidence based on deoxyribonucleic acid homology supports the abandonment of the genus Hydrogenomonas. Pseudomonas facilis (formerly Hydrogenomonas facilis) is closely related to the nonautotrophic species P. delafieldii. P. facilis and Alcaligenes eutrophus (often called H. eutropha) are not related to each other or to other hydrogen bacteria and pseudomonads studied.
Tan K B - - 1972
Poxvirus has a deoxyribonucleic acid polymerase activity that remains associated with the virus despite repeated centrifugation through sucrose gradients. Highly purified poxvirus preparation can adsorb deoxyribonucleic acid polymerase from cytoplasmic extracts of cells containing such an activity. These results indicate that caution must be used in assuming that an enzyme ...
Dion A S - - 1971
Escherichia coli B infected by the DD mutant of T4, am N116, is stimulated to initiate deoxyribonucleic acid accumulation by 1 to 10 mm spermidine but not by 10 mm putrescine. The syntheses of putrescine and spermidine in cells infected by T4D and the mutant are similar, although slight differences ...
Rose J A - - 1971
The two complementary strand species of 5-bromodeoxyuridine-substituted, adenovirus-associated virus type 2 (AAV-2) deoxyribonucleic acid were preparatively separated in CsCl density gradients and further purified by sedimentation through 5 to 20% sucrose. The base composition of each strand species was determined, and it was found that the species banding at a ...
Bachrach U - - 1971
The efficiencies of the various methods used for phage concentration have been compared. The two-phase concentration method (with polyethylene glycol and dextran sulfate) gave maximal recoveries of infectivity for coliphages of the T-even and T-odd series and for ribonucleic acid phages and single-stranded deoxyribonucleic acid phages. Precipitation of phages by ...
Yu M C - - 1971
The ultrastructural changes in cerebellar encephalopathy induced by intravenous injection of poly I:C in young chickens were studied. The neuroglia and the small blood vessels showed the most severe injury. In the astroglia, initial alterations consisted of a mild cytoplasmic swelling whereas terminally, evagination of the outer nuclear membrane, formation ...
Leffler H R - - 1971
Chromatin isolated from soybean (Glycine max L., var. Wayne) hypocotyls was capable of catalyzing the polymerization of labeled deoxyribonucleoside triphosphate in the presence of the three other deoxyribonucleoside triphosphates into a trichloroacetic acid-insoluble product. This product was insensitive to base hydrolysis and ribonuclease, but was sensitive to acid hydrolysis and ...
Sedliaková M - - 1971
Changes in the resistance of cells of Escherichia coli B/r Hcr(+)thy(-)trp(-) to ultraviolet radiation were investigated after the following pretreatments: (i) amino acid starvation which, according to previous conclusions, enabled the cells to complete replication cycles of deoxyribonucleic acid (DNA); (ii) amino acid starvation during which the synthesis of DNA ...
Goldring E S - - 1971
A series of petite mutants of Saccharomyces cerevisiae, generated after treatment for various times with ethidium bromide, was isolated, and the mitochondrial deoxyribonucleic acid size for each member was estimated. It was found that, as the treatment time with ethidium bromide was increased, the mitochondrial deoxyribonucleic acid isolated from the ...
Hattman S - - 1971
The 6-methylaminopurine (MAP) content of P22 deoxyribonucleic acid has been analyzed as a function of the host specificity it carries. A 40 to 50% reduction in MAP level occurs as a result of growth in host cells defective in the ability to confer LT specificity.
Krisch H M - - 1971
Deoxyribonucleic acid replication and genetic recombination were investigated after infection of Escherichia coli with ligase-deficient rII bacteriophage T4D. The major observations are: (i) deoxyribonucleic acid synthesis is discontinuous, (ii) the discontinuities are more slowly repaired than in wild-type infection, (iii) host ligase is required for viability, and (iv) genetic recombination ...
Lachica R V - - 1971
Based on the metachromatic property of Toluidine Blue O, three, convenient agar-diffusion methods have been developed that enable detection of the nuclease of Staphylococcus aureus at concentrations as low as 0.005 mug/ml in agar and broth cultures. The interactions of agar and deoxyribonucleic acid with Toluidine Blue O are discussed.
Meyn R E - - 1971
Two mammalian cell lines, Chinese hamster ovary (CHO) which can recover colony-forming ability between fractionated doses of ultraviolet light (UV), and Chinese hamster B-14FAF28 which cannot recover, were tested for the ability to bypass UV-induced photoproducts in DNA during postirradiation DNA synthesis. The molecular weight distributions of newly synthesized DNA ...
Ramírez Martínez J R - - 1971
Details of the sequential morphological changes occurring during yeastlike to mycelial-form conversion of the dimorphic pathogen Paracoccidioides brasiliensis are described and illustrated by photomicrographs. Conversion of yeastlike to hyphal morphology was initiated by changing the temperature of incubation from 37 to 23 C. Production by the parent yeastlike cells of ...
Mullinix K P - - 1971
Exposure of growing cells to low levels of N-hydroxyurethan (approximately 0.05 m) resulted in loss of colony-forming ability. This was accompanied by degradation of cellular deoxyribonucleic acid. When the concentration of N-hydroxyurethan was increased to 0.2 m, bacteriostasis was the primary manifestation. The lethal action of the drug was prevented ...
Tyeryar F J - - 1970
The requirements and characteristics of Pasteurella novicida transformations in liquid suspensions were studied. Transformation frequencies of 0.1 to 0.3% were routinely obtained when recipient cells were harvested from 16-hr agar plates and higher than 1% when logarithmic-phase broth-grown cells were used. Calcium ions were essential for transformations. The deoxyribonucleic acid ...
Renger H C - - 1970
Cesium chloride centrifugation of DNA extracted from cells of blood strain Trypanosoma lewisi revealed a main band, rho = 1.707, a light satellite, rho = 1.699, and a heavy satellite, rho = 1.721. Culture strain T. lewisi DNA comprised only a main band, rho = 1.711, and a light satellite, ...
Throm E - - 1970
Yeast cells of mating type alpha excrete a sex factor which inhibits cell division and deoxyribonucleic acid replication but not ribonucleic acid or protein synthesis in cells of opposite mating type a.
Kennelly J J - - 1970
To estimate the duration of oocyte DNA synthesis 36, 3-day-old female rabbits received 3, 6, 9, 12, 15, or 18 injections of tritiated thymidine (thy-(3)H) at hourly intervals. The ovaries, removed at 1, 10, or 20 days after the first injection, were radioautographed. Counts made of the number of silver ...
Ciferri O - - 1970
A survey was made of the capacity of competent cells of Bacillus subtilis to take up synthetic polynucleotides. Polydeoxyribonucleotides but not polyribonucleotides are taken up by the cells. Both types of polynucleotide failed to compete with transforming deoxyribonucleic acid in the transformation assay whereas both stimulated amino acid incorporation. The ...
Ryan M F - - 1970
Two species of flour beetles, Tribolium confusum and Tribolium castaneum, respond to neutral pith disks impregnated with aqueous extracts of their pupae in such a way that the adults and larvae tend to select the extract of the other species. These findings have implications for the population ecology of Tribolium.
Chai N C - - 1970
We examined the gross nuclear morphology of Escherichia coli 15T(-) grown in different media with doubling times ranging from 22 to 270 min. In slowly growing cells, deoxyribonucleic acid synthesis was measured by autoradiography and shown to occur with greatest probability during the first two-thirds of the division cycle. In ...
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