DNA BASE COMPOSITION OF CYTOPHAGA MARINOFLAVA N. SP. DETERMINED BY BUOYANT DENSITY MEASUREMENTS IN CESIUM CHLORIDE

1966 ◽  
Vol 12 (6) ◽  
pp. 1099-1103 ◽  
Author(s):  
R. R. Colwell ◽  
R. V. Citarella ◽  
P. K. Chen
Keyword(s):  
Nucleic Acid ◽  
Base Composition ◽  
Marine Bacterium ◽  
Deoxyribonucleic Acid ◽  
Buoyant Density ◽  
Cesium Chloride ◽  
Dna Base Composition ◽  
Density Measurements ◽  
Dna Base ◽  
Relationship Of

A marine bacterium, NCMB 397, host strain for bacteriophages NCMB 384 and 385, has been subjected to taxonoinic analysis. Overall base composition of the highly purified deoxyribonucleic acid was determined and found to be 37 moles % guanine + cytosine. The phenetic and nucleic acid data suggest significant relationship of this strain and members of the genus Cytophaga. A description of Cytophaga marinoflava n. sp. is presented.

DNA base composition and the taxonomy of the Oomycetes

1972 ◽  
Vol 18 (7) ◽  
pp. 963-968 ◽  
Author(s):  
Beverley R. Green ◽  
Michael W. Dick
Keyword(s):  
Base Composition ◽  
Gradient Centrifugation ◽  
Cesium Chloride ◽  
Generic Level ◽  
Dna Base Composition ◽  
Composition Data ◽  
General Base ◽  
Dna Base ◽  
Cscl Gradient

The DNA base compositions of seven members of the Saprolegniaceae were determined by cesium chloride (CsCl) gradient centrifugation. In general, base composition data correlated with morphological classification, but in several cases it indicated the necessity for revisions. In particular, Achlya inflata (eccentric group) was 42% guanine–cytosine (GC), while A. racemosa, A. sparrowii, and A. colorata (racemose group) were 51–52% GC.Two isolates of Saprolegnia diclina and one of S. parasitica were 58–59% GC and all contained 10–20% of a lighter density satellite DNA.Analysis of thermal denaturation curves by a modification of De Ley's method (J. Theoret. Biol. 22: 89 (1969)) showed that as little as 7.4% GC difference represents a large difference in DNA sequence homology. Therefore, base composition data by itself can provide a rigorous aid to the classification of the oomycetous fungi at the generic level.

scholarly journals Lifestyle and DNA base composition in polychaetes

2016 ◽  
Vol 48 (12) ◽  
pp. 883-888
Author(s):  
Andrea Tarallo ◽  
Maria Cristina Gambi ◽  
Giuseppe D'Onofrio
Keyword(s):  
Metabolic Rate ◽  
Base Composition ◽  
Gc Content ◽  
Active Lifestyle ◽  
Dna Base Composition ◽  
Polychaete Species ◽  
Dna Base ◽  
Biased Gene Conversion ◽  
Relationship Of ◽  
Genomic Gc Content

A comparative analysis of polychaete species, classified as motile and low-motile forms, highlighted that the former were characterized not only by a higher metabolic rate (MR), but also by a higher genomic GC content. The fluctuation of both variables was not affected by the phylogenetic relationship of the species. Thus, present results further support that a very active lifestyle affects MR and GC at the same time, showing an unexpected similarity between invertebrates and vertebrates. In teleosts, indeed, a similar pattern has been also observed in comparisons of migratory and nonmigratory species. A cause-effect link between MR and GC has not yet been proved, but the fact that the two variables are significantly linked in all the organisms so far analyzed is, most probably, of relevant biological and evolutionary meaning. The present results fit very well within the frame of the metabolic rate hypothesis proposed to explain the DNA base composition variability among organisms. On the contrary, the thermostability hypothesis was not supported. At present, no data about the recombination rate in polychaetes were available to test the biased gene conversion (BGC hypothesis).

DNA BASE COMPOSITION OF SOME FREE-LIVING NEMATODE SPECIES

1969 ◽  
Vol 11 (4) ◽  
pp. 993-1000 ◽  
Author(s):  
R. Behme ◽  
J. Pasternak
Keyword(s):  
Refractive Index ◽  
Base Composition ◽  
Buoyant Density ◽  
Gc Content ◽  
Nematode Species ◽  
Refractive Index Gradient ◽  
Free Living ◽  
Dna Base Composition ◽  
Dna Base ◽  
Dnase Treatment

The mean base compositions (% GC) of DNA samples from five free-living nematodes were determined by CsCl equilibrium buoyant-density centrifugation and thermal denaturation studies. Both methods gave similar results indicating that there is no extensive replacement of the usual bases in nematode DNA. From the ultracentrifugation studies the % GC content of the DNA of Caenorhabditis briggsae (Dougherty and Nigon, 1949) Dougherty, 1953, Turbatrix aceti (Müller, 1783) Peters, 1927, Rhabditis (Rhabditis) anomala Hertwig, 1922 (Dougherty 1955), Panagrellus redivivus (Linn, 1767) T. Goodey, 1945, and Panagrellus silusiae (de Man, 1913) T. Goodey, 1945 was 36, 40, 42, 44 and 44, respectively.The sample of DNA from T. aceti showed two distinct ultraviolet absorbing bands in a CsCl gradient. The band at 1.688 g/cm3 proved to be a polysaccharide. It gave a distinctive refractive index pattern when viewed with the schlieren optical system, was insensitive to DNase treatment and was removed by a-amylase treatment. On the other hand, the material banding at 1.699 g/cm3 was shown to be DNA. This band produced no disturbance in the refractive index gradient. It was not altered by a-amylase treatment, but it was DNase sensitive.Since P. redivivus and P. silusiae were found to have the same DNA base composition their ability to interbreed was examined. These two forms were cross-fertile and the offspring were fully fertile.

Properties of a D-quinovosamine-producing Achromobacter

1968 ◽  
Vol 14 (2) ◽  
pp. 165-171 ◽  
Author(s):  
R. R. Colwell ◽  
E. J. Smith ◽  
G. B. Chapman
Keyword(s):  
Deoxyribonucleic Acid ◽  
Buoyant Density ◽  
Cesium Chloride ◽  
Wall Structure ◽  
Gram Negative Bacteria ◽  
Negative Bacterium ◽  
Acid Base ◽  
Gram Negative ◽  
Density Measurements ◽  
Ultrathin Sections

The bacterial mucopolysaccharide of a Gram-negative bacterium, Georgetown strain COC-21, includes a hexosamine component, D-quinovosamine. The bacterium has been identified and classified as Achromobacter georgiopolitanum n. sp. and a description of the organism is given. The overall deoxyribonucleic acid base composition, determined by buoyant density measurements in cesium chloride, is 41 moles %. Electron micrographs of ultrathin sections reveal a double-layered cell wall structure typical of the Gram-negative bacteria.

Deoxyribonucleic acid base composition of isolates of Rhizobium japonicum

1969 ◽  
Vol 15 (5) ◽  
pp. 490-493 ◽  
Author(s):  
Gerald H. Elkan
Keyword(s):  
Statistical Analysis ◽  
Base Composition ◽  
Deoxyribonucleic Acid ◽  
Genetic Relatedness ◽  
The Other ◽  
Rhizobium Japonicum ◽  
Acid Base ◽  
Dna Base Composition ◽  
Dna Base ◽  
Mole Percentage

The DNA base composition (expressed as mean molar percentages of guanine and cytosine) of 25 strains of Rhizobium japonicum was determined to study the genetic relatedness of these strains. The mole percentage GC ranged from 61.47 to 64.09. Statistical analysis of the DNA base ratios of the 25 isolates revealed that 16 of these differed significantly in GC ratios from some of the other strains.

Deoxyribonucleic acid relationships among members of the genus Aeromonas

1979 ◽  
Vol 25 (5) ◽  
pp. 579-586 ◽  
Author(s):  
Jan I. MacInnes ◽  
Trevor J. Trust ◽  
Jorge H. Crosa
Keyword(s):  
Aeromonas Hydrophila ◽  
Base Composition ◽  
Deoxyribonucleic Acid ◽  
Single Species ◽  
Aeromonas Salmonicida ◽  
Dna Duplexes ◽  
Dna Base Composition ◽  
Homology Groups ◽  
Dna Base ◽  
Significant Divergence

Polynucleotide sequences among 24 motile and 11 non-motile aeromonads were studied by analysis of deoxyribonucleic acid – deoxyribonucleic acid (DNA–DNA) duplexes with endonuclease S1. In addition, DNA base composition (mole % guanine and cytosine (G + C) and relative genome sizes were determined for selected strains. Large variations in genome size were found and % GC ranged from 57.1 to 62.9%. On the basis of the strains examined, the Genus Aeromonas consists of two genotypically legitimate groups: a diverse group of motile aeromonads, and the genetically more homogeneous non-motile aeromonads, comprising the species Aeromonas salmonicida. Internal homology groups could not be demonstrated within the motile aeromonads, and significant divergence in related sequences was indicated. This diverse motile group forms the single species Aeromonas hydrophila.

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