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Biomedical subjects

F R Katterman

Publications and source records attributed to F R Katterman.

17 recordsLinked to original sources
PubMed1986

Cytokinin activity induced by thidiazuron.

The diphenylurea derivative thidiazuron induces a variety of cytokinin responses. Levels above 5 x 10(-9) molar and 4 x 10(-7) molar stimulate maximum soybean callus growth and radish cotyledon expansion, respectively. A wider range of dose response related effects follows thidiazuron induced tobacco plant regeneration. Analysis of soybean callus extracts strongly suggests that thidiazuron treatment creates an accumulation and/or synthesis of purine cytokinins, able to induce the growth, expansion and regeneration, mentioned above.

Journal Article↗
PubMed1983

An effective method of DNA isolation from the mature leaves of Gossypium species that contain large amounts of phenolic terpenoids and tannins.

Purified and unstained nuclei were isolated from the leaves of several Gossypium species (diploid and tetraploid) by means of a citrate buffer (pH 5.0), Triton X-100 (5%), and a reducing sugar (1M glucose). DNA, previously unobtainable, was then extracted from the nuclei by conventional means. Comparisons of final DNA yield were made between three methods of purification: namely, the standardized ribonuclease procedure, hydroxyapatite chromatography and equilibrium density centrifugation in cesium chloride. The latter method produce the lowest, yet purest, yield of DNA for renaturation studies in Gossypium.

Cell Nucleus↗
PubMed1976

Analysis of repetitive DNA in three species of Gossypium.

The rate of reassociation of denatured DNA was determined for two selected diploid species, Gossypium thurberi (D genome) and G. arboreum (A genome), and one allotetraploid species, G. hirsutum (AD genome). The relative genome size and DNA content of the chromosomes of the diploids were A greater than D. Renaturation curves indicated that the differences in genome sizes were due primarily to the repetitive DNA content.

Chromosomes↗
PubMed1976

Mechanism of nuclear DNA replication in radicles of germinating cotton.

The mechanism of nuclear DNA replication in radicles of germinating cotton (Gossypium barbadense) was investigated. Pulse-labeling with [(3)H]thymidine indicates that replication intermediates are of small molecular weight (4-10S) and behave as if single-stranded. Prolonged labeling indicates that intermediates are of discrete size, suggesting a mechanism of discontinuous replication. Electron microscopy of nuclear DNA demonstrates a complex architecture which may include "eye forms" and "forks" similar to those reported in prokaryotes and animal systems. The possible universality of DNA replication mechanisms is discussed.

Journal Article↗
PubMed1975

Storage and metabolism of poly(adenylic acid)-mRNA in germinating cotton seeds.

When the RNA from both the nucleus and polysomes of germinated cotton seeds were fractionated on poly(U)-cellulose columns it was found that both contained poly(A)-RNA. In ungerminated seeds most of the poly(A)-RNA is located in the nucleus of the cell. 3'-Deoxyadenosine was found to inhibit the synthesis of both nuclear and polysomal poly(A) by 75% in germinated seeds, but had little or no effect on protein synthesis during the first 6 hr of germination. After this time 3'-deoxyadenosine had a pronounced inhibitory effect on protein synthesis presumably due to the inhibition of poly(A) addition to newly synthesized mRNA.

Base Sequence↗
PubMed1975

Chromatin and DNA synthesis associated with nuclear membrane in germinating cotton.

The synthesis of nuclear DNA and possible attachment sites of chromatin in the cells of cotton (Gossypium barbadense) radicles during germination was investigated. Biochemical analysis of nuclear membrane fragments or Sarkosyl-magnesium-membrane complexes indicates that the DNA, including newly replicated DNA, is attached to the nuclear membranes during periods of active synthesis. Electron micrographs of nuclear membrane fragments indicate a physical association between chromatin fibers and the membranes. The attachment site appears to be proteinaceous, since the chromatin is released by protein degradative enzymes as evidenced by biochemical techniques and electron microscopic observations. Short-term labeling results in incorporation into a membrane-associated product indistinguishable from the bulk of nuclear DNA. DNA polymerase activity is also associated with nuclear membrane preparations in which [3H]thymidine triphosphate is incorporated into an acid-insoluble. DNase-sensitive product.

Cell Membrane↗
PubMed1975

Nucleic Acid Metabolism during Germination of Pima Cotton (Gossypium barbadense).

The nucleic acid metabolism in long staple Pima cotton (Gossypium barbadense L.) was examined during the first 48 hours of germination at 34 C. Specific activity analysis of pulselabeled nucleic acids indicated that the first significant incorporation of precursors into DNA occurs at approximately 18 hours when the radicles are emerging with a peak of incorporation occurring at 36 hours. Specific activity of total RNA also indicate peak values at 18 hours and 36 hours of germination. Sucrose gradient analysis of pulse-labeled RNA indicated that the synthesis of ribosomal RNA reached a maximum value during the 18-hour period and that there was a shift in transcriptional products during the 30- to 36-hour interval. The extraction of the RNA from pulse-chase studies and from labeled polyribosomes suggest that a significant portion of the RNA synthesized at 36 hours appears to be messenger RNA and at 18 hours is ribosomal RNA. These distinct patterns of metabolism during germination provide a background for studying nucleic acid metabolism during chilling damage.

Journal Article↗
PubMed1966

RNA composition in cotton.

Nucleotide compositions of soluble (sRNA), whole-cell, and in one instance particulate and nonparticulate, RNA of embryos, cotyledons (dark and light-grown), leaves, stems, and roots of Gossypium hirsutum were compared. Evidence of substantial differences in the overall compositions of the RNAs was not obtained. However, a tendency for some plant parts to differ, particularly in sRNA composition, and that of the cotyledons (including particulate and nonparticulate RNA) to change during the formation of chlorophyll, was indicated by small but statistically significant shifts in certain nucleotide components.

Journal Article↗