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  • Hydra mutant  (2)
  • In situ hybridization  (2)
  • Inorganic Chemistry  (2)
Materialart
Erscheinungszeitraum
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 183 (1977), S. 193-206 
    ISSN: 1432-041X
    Schlagwort(e): Hydra mutant ; Morphogenetic substances ; Head formation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A mutant ofHydra attenuata is analysed, theaberrant, which is distinct from the wild type in having a smaller head with fewer tentacles and only half the number of head-specific cells. The rate of head and foot regeneration and the doubling time are slower inaberrants than in normal hydra. The lower head-forming potential is paralleled by a reduced concentration of head-specific morphogens: compared to the wild type, in theaberrant the concentration of head activator is reduced to 70% in the head and to 50% in the body, the concentration of head inhibitor is reduced to 50% in the head and to 80% in the body. Theaberrant is more sensitive (3 times) to added head activator and less sensitive (〉5 times) to added head inhibitor than the wild type. The slower rate of foot regeneration is paralleled by a lower content of foot-specific morphogens: compared to the wild type, in theaberrant the foot activator is reduced to 40% and the foot inhibitor to 70%.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 183 (1977), S. 207-214 
    ISSN: 1432-041X
    Schlagwort(e): Hydra mutant ; Morphogenetic substances ; Bud formation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Non-budding mutants ofChlorohydra viridissima regenerate heads 6 h faster thanHydra attenuata and the number of tentacles per head is higher. The polarity in pieces from the gastric region is the more labile, the smaller the pieces are. In regenerates heads and tentacles form much more frequently than feet, giving rise to bipolar or multiheaded structures. Buds very seldom form under normal conditions, but they occasionally occur in regenerating animals with two cut surfaces. The higher head-forming potential in the mutant is paralleled by a higher head-activator concentration (20-fold in head, 4-fold in body), than inHydra attenuata, which is not accompanied by an equivalent increase in head-inhibitor concentration (1.4-fold in head, 2-fold in body). The foot-activator concentration is slightly reduced (1.3-fold), the foot-inhibitor concentration is higher (1.6-fold) than inH. attenuata. The mutant is extremely insensitive to head activator, relatively insensitive to head inhibitor and foot inhibitor, but sensitive to foot activator.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-2242
    Schlagwort(e): rDNA sites ; Centromeric repetitive DNA ; Telomere ; In situ hybridization ; Southern hybridization ; Ag-NOR ; Cowpea ; Physical maps
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A knowledge of genome organization is important for understanding how genomes function and evolve, and provide information likely to be useful in plant breeding programmes involving hybridization and genetic manipulation. Molecular techniques, including in situ hybridization, molecular cloning and DNA sequencing, are proving valuable tools to investigate the structure, organization, and diversity of chromosomes in agricultural crops. Heterologous labelled 18 s-5.8 s-25 s (pTa71) and 5 s rDNAs (pTa794) were used for in situ hybridization on Vigna unguiculata (L.) Walp. chromosomes. Hybridization with 18 s-5.8 s-25 s rRNA gene probes occurred at the same chromosomal sites which were positive to the CMA fluorochrome. Silver staining of nucleolar-organizing regions indicated that all the rDNA sites detected using the 18 s-5.8 s-25 s rRNA gene probe possessed active genes. Degenerate telomeric repeats gave hybridization signals at the telomeres of most chromosomes and no intercalary sites were detected at metaphase; the sequences appear to have no preferential distribution in interphase nuclei. A repetitive DraI family from V. unguiculata was cloned (pVuKB1) and characterized. The DraI repeat is 488 nucleotides long, AT rich (74%), and hybridized on all chromosomes in the centromeric areas. The presence of this sequence family was investigated by Southern hybridization in different Vigna species and other Leguminoseae. It was only detected in V. unguiculata, and hence represents a species-specific DNA sequence.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 244 (1994), S. 420-425 
    ISSN: 1617-4623
    Schlagwort(e): Pennisetum glaucum ; Satellite DNA ; In situ hybridization ; Centromeric heterochromatin ; Methylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A HaeIIl monomer of a repetitive DNA family from Pennisetum glaucum (L.) R. Br. cv. Massue has been cloned and characterized. The repeat is 137 bp long and is organized in head-to-tail orientation in tandem arrays. The HaeIII monomer contains 55% A+T residues. The distribution of this highly repetitive sequence in different Pennisetum species and in other cereals was investigated. The HaeIII satellite is present in all Pennisetum species investigated but absent from other genera examined. In situ hybridization revealed a centromeric localization of this sequence on all seven chromosome pairs and indicated chromosome-specific differences in copy number. Methylation was investigated by comparative restriction enzyme analysis (Msp/HpaII) which showed a greater extent of methylation of the internal C of the enzyme recognition site 5′-CCGG. A South-Western analysis, using an anti-methylcytosine antibody to examine the methylation status in P. glaucum confirmed that the sequence is not highly methylated.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 185 (1929), S. 107-129 
    ISSN: 0863-1786
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 0044-2313
    Schlagwort(e): Transition metal substituted phosphaalkenes ; isophosphaalkyne complex ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Transition Metal Substituted Acylphosphanes and Phosphaalkenes. 17. Synthesis and Structure of the μ-Isophosphaalkyne Complexes [(η5-C5H5)2(CO)2Fe2(μ-CO)(μ-C=PC6H2R3)] (R = Me, iPr, tBu).Condensation of (η5-C5H5)2(CO)2Fe2(μ-CO)(μ-CSMe)}+SO3CF3- (6) with 2,4,6-R3C6H2PH(SiMe3) (7) (a: R = Me, b: R = iPr, c: R = tBu) affords the complexes (η5-C5H5)2(CO)2Fe2(μ-CO)(η-C=PC6H2R3-2,4,6) (9 a-c) with edge-bridging isophosphaalkyne ligands as confirmed by the x-ray structure analysis of 9 a.
    Notizen: Die Kondensation des μ-Carbinkomplexes {(η5-C5H5)2(CO)2Fe2(μ-CO)(μ-CSMe)}+SO3CF3- (6) mit den Phosphanen 2,4,6-R3C6H2PH(SiMe3) (7) (a: R = Me, b: R = iPr, c: R = tBu) liefert die Komplexe (η5-C5H5)2(CO)2Fe2(μ-CO)(η-C=PC6H2R3-2,4,6) 9a-c, die die neuartigen Isophosphaalkine C≡P-Aryl als Brückenliganden tragen. Von 9 a wurde eine Röntgenstrukturanalyse durchgeführt.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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