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G Kahl

Publications and source records attributed to G Kahl.

63 records · Page 4Linked to original sources
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Plant DNA fingerprinting with radioactive and digoxigenated oligonucleotide probes complementary to simple repetitive DNA sequences.

The existence of hypervariable DNA sequences in nuclear genomes, and the use of appropriate "fingerprinting" probes to detect them, has gained widespread scientific interest, and also led to multiple applications in diverse areas. Two years ago, the new technique of "DNA fingerprinting" was also introduced into the analysis and characterization of plant genomes, initially by using human or M13 minisatellites as probes. In the present article, we demonstrate the applicability for plant DNA fingerprinting of oligonucleotide probes specific for simple repetitive DNA sequences. We show that various levels of intra- and interspecific polymorphisms can be detected; the information to be gained depends on the optimal combination of probe and species. Variety-specific patterns were obtained in several cases. Some probes revealed variability between individuals. Somatic variability was not observed. Different DNA isolation and purification procedures were tested in order to introduce a fast and easy-to-perform isolation method suitable for a large variety of plant species. Nonradioactive fingerprinting was performed using digoxigenated oligonucleotides as probes. Banding patterns obtained with radioactive and digoxigenin-based labeling techniques proved to be of similar quality.

Base Sequence↗
PubMedDate not supplied

Activation of chromatin-bound DNA-dependent RNA polymerase (E.C. 2.7.7.6.) in plant storage tissue slices.

The synthesis of RNA by chromatin-bound RNA polymerase (E.C. 2.7.7.6.) from white potato tubers proceeds at a low rate, which is enhanced after slicing the tissue, however. Concomitantly DNA template availability as measured with saturating amounts of Escherichia coli polymerase is diminished drastically. Nearest neighbor frequency analysis proved that the RNA synthesized on chromatin of intact tubers is different from that synthesized on chromatin of sliced tissue. The RNA polymerase of white potato tubers is dependent on all four ribonucleoside triphosphates and a divalent metal ion such as Mg2+ or Mn2+ and totally inhibited by the presence of pyrophosphate. Actinomycin D blocks the formation of the RNA product, which could be shown to be a heteropolymer by nearest neighbour frequency technique. The Km of the chromatin-bound enzyme with regard to ATP, GTP, CTP and UTP was 5.1 X 10(-5) M, 1.6X10(-5) M, 0.9X10(-5) M and 0.45X10(-5) M/l respectively. alpha-amanitin inhibits the overall activity to about 50%, which indicates the presence of equal amounts of polymerase I and polymerase II.

Chromatin↗