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The nucleotide sequence of a 2.4 kb Dral-EcoRV fragment of pColD-CA23 DNA was determined. The segment of DNA contained the colicin D structural gene (cda) and the colicin D immunity gene (cdi). From the nucleotide sequence it was deduced that colicin D had a molecular weight of 74,683 D and that the immunity protein had a molecular weight of 10,057 D. The(More)
Myxamebas of Polysphondylium violaceum were grown in liquid medium and processed for electron microscopy. Mitosis is characterized by a persistent nuclear envelope, ring-shaped extranuclear spindle pole bodies (SPBs), a central spindle spatially separated from the chromosomal microtubules, well-differentiated kinetochores, and dispersion of the nucleoli.(More)
Amebae of D. discoideum on coverslips were fixed in situ with glutaraldehyde and permeabilized with Triton X-100. Of six antibodies tested, only a monoclonal antibody to yeast tubulin consistently gave bright fluorescence. Counterstaining with DAPI facilitated the identification of interphase and mitotic stages. Most microtubules (MTs) in interphase amebae(More)
The antitubulin fungicide benomyl suppressed the linear growth of Neurospora crassa wild type strain St. Lawrence 74 at micromolar concentrations. The rate of germination of macroconidia was not affected. Macroconidia exposed to 1.7 microM benomyl for 5 h formed multiple germ tubes. When germlings incubated for 4 h were exposed to 1.7 microM benomyl for 3(More)
Actin and tubulins of Phytophthora infestans germlings were detected with monoclonal antibodies on Western blots of crude extracts separated by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The Mr of actin was approximately 43,000, whereas alpha- and beta-tubulin, which migrated as a single band, had an Mr of 53,000.(More)
Ten mitotic spindles from Dictyostelium discoideum have been studied by electron microscopy of serial sections. We have used computer graphics to track individual microtubules (MTs) in three dimensions and to compare seven spindles at different stages of anaphase and telophase. The central spindle of early anaphase is formed by the interdigitation of two(More)
We studied mitosis in vegetative amebae of Dictyostelium discoideum by phase-contrast microscopy of live and flat-embedded cells, by time-lapse microcinematography, and by electron microscopy of ultrathin sections. The mean time from early prophase to the end of cytokinesis was 10 min 32 s (range: 6 min 23 s to 15 min 40 s). The start of anaphase divided(More)
Expression of genes involved in nikkomycin production in Streptomyces tendae was investigated by two-dimensional gel electrophoresis of cellular proteins. Ten gene products (P1-P10) were identified that were synthesized when nikkomycin was produced; these proteins were not detected in non-producing mutants. N-terminal sequences of six of the 10 proteins(More)
We investigated the microtubule (MT) cytoskeleton and microtubule centers (MTC) in undifferentiated amoebae by indirect immunofluorescence with six monoclonal antitubulin antibodies, and by transmission electron microscopy and immunogold ultracytochemistry. Interphase amoebae of both species contain a distinct cytoplasmic complex of MTs, which is more(More)
Strain Bali I of Allomyces arbuscula is infected with a RNA virus; strain North Carolina is not. The virus appears to be avirulent, for strain Bali I showed no signs of pathogenicity. Virus aggregates occurred mostly in the cytoplasm during different stages of the gametophytic and sporophytic generations. Small intra-nuclear aggregates were found only in(More)