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K Sampson - One of the best experts on this subject based on the ideXlab platform.

  • Phallacidin stains the kinetochore region in the mitotic spindle of the green algae Oedogonium spp.
    Protoplasma, 2020
    Co-Authors: K Sampson, Jeremy D. Pickett-heaps
    Abstract:

    We found previously that in living cells ofOedogonium cardiacum andO. donnellii, mitosis is blocked by the drug cytochalasin D (CD). We now report on the staining observed in these spindles with fluorescently actin-labeling reagents, particularly Bodipy FL Phallacidin. Normal mitotic cells exhibited spots of staining associated with chromosomes; frequently the spots appeared in pairs during prometaphase-metaphase. During later anaphase and telophase, the staining was confined to the region between chromosomes and poles. The texture of the staining appeared to be somewhat dispersed by CD treatment but it was still present, particularly after shorter (

  • Phallacidin stains the mitotic spindle of the diatom pinnularia spp
    Cell Biology International, 2004
    Co-Authors: K Sampson
    Abstract:

    Mitotic spindles of the diatom Pinnularia viritiformis stained with the fluorescent actin-labelling reagent bodipyPhallacidin revealed actin among the chromosomes and extending along the spindle to the poles. This is the first report of actin's presence within spindles of this ecologically important group of organisms. Since diatom mitoses have a number of marked differences compared to that of many other eukaryotes (Int Rev Cytol 128 (1991) 63; Cell 14 (1978) 455), the present observations substantially extend the diversity of mitotic spindle types in which there is evidence of spindle actin.

  • Phallacidin stains the kinetochore region in the mitotic spindle of the green algaeOedogonium spp.
    Protoplasma, 2001
    Co-Authors: K Sampson, Jeremy D. Pickett-heaps
    Abstract:

    We found previously that in living cells of Oedogonium cardiacum and O. donnellii , mitosis is blocked by the drug cytochalasin D (CD). We now report on the staining observed in these spindles with fluorescently actin-labeling reagents, particularly Bodipy FL Phallacidin. Normal mitotic cells exhibited spots of staining associated with chromosomes; frequently the spots appeared in pairs during prometaphase-metaphase. During later anaphase and telophase, the staining was confined to the region between chromosomes and poles. The texture of the staining appeared to be somewhat dispersed by CD treatment but it was still present, particularly after shorter (

  • Phallacidin stains the kinetochore region in the mitotic spindle of the green algae oedogonium spp
    Protoplasma, 2001
    Co-Authors: K Sampson, J D Pickettheaps
    Abstract:

    We found previously that in living cells ofOedogonium cardiacum andO. donnellii, mitosis is blocked by the drug cytochalasin D (CD). We now report on the staining observed in these spindles with fluorescently actin-labeling reagents, particularly Bodipy FL Phallacidin. Normal mitotic cells exhibited spots of staining associated with chromosomes; frequently the spots appeared in pairs during prometaphase-metaphase. During later anaphase and telophase, the staining was confined to the region between chromosomes and poles. The texture of the staining appeared to be somewhat dispersed by CD treatment but it was still present, particularly after shorter (<2 h) exposure. Electron microscopy of CD-treated cells revealed numerous spindle microtubules (MTs); many kinetochores had MTs associated with them, often laterally and some even terminating in the kinetochore as normal, but the usual bundle of kinetochore MTs was never present. As treatment with CD became prolonged, the kinetochores became shrunken and sunk into the chromosomes. These results support the possibility that actin is present in the kinetochore ofOedogonium spp. The previous observations on living cells suggest that it is a functional component of the kinetochore-MT complex involved in the correct attachment of chromosomes to the spindle.

D Todorov - One of the best experts on this subject based on the ideXlab platform.

Jeremy D. Pickett-heaps - One of the best experts on this subject based on the ideXlab platform.

  • Phallacidin stains the kinetochore region in the mitotic spindle of the green algae Oedogonium spp.
    Protoplasma, 2020
    Co-Authors: K Sampson, Jeremy D. Pickett-heaps
    Abstract:

    We found previously that in living cells ofOedogonium cardiacum andO. donnellii, mitosis is blocked by the drug cytochalasin D (CD). We now report on the staining observed in these spindles with fluorescently actin-labeling reagents, particularly Bodipy FL Phallacidin. Normal mitotic cells exhibited spots of staining associated with chromosomes; frequently the spots appeared in pairs during prometaphase-metaphase. During later anaphase and telophase, the staining was confined to the region between chromosomes and poles. The texture of the staining appeared to be somewhat dispersed by CD treatment but it was still present, particularly after shorter (

  • Phallacidin stains the kinetochore region in the mitotic spindle of the green algaeOedogonium spp.
    Protoplasma, 2001
    Co-Authors: K Sampson, Jeremy D. Pickett-heaps
    Abstract:

    We found previously that in living cells of Oedogonium cardiacum and O. donnellii , mitosis is blocked by the drug cytochalasin D (CD). We now report on the staining observed in these spindles with fluorescently actin-labeling reagents, particularly Bodipy FL Phallacidin. Normal mitotic cells exhibited spots of staining associated with chromosomes; frequently the spots appeared in pairs during prometaphase-metaphase. During later anaphase and telophase, the staining was confined to the region between chromosomes and poles. The texture of the staining appeared to be somewhat dispersed by CD treatment but it was still present, particularly after shorter (

Zhivko Zhelev - One of the best experts on this subject based on the ideXlab platform.

W W Webbt - One of the best experts on this subject based on the ideXlab platform.

  • Fluorescence staining of the actin cytoskeleton in living cells with 7-nitrobenz-2-oxa- 1 ,3-diazole-Phallacidin (Phallacidin/phalloidin/immunofluorescence/cytoplasmic streaming/Chara australis)
    2020
    Co-Authors: Larry S Barak, R Rogers, Eugene A Nothnagelt, W W Webbt
    Abstract:

    An active fluorescent derivative of the actin- binding mushroom toxin Phallacidin has been synthesized. Convenient methods were developed to stain actin cytoskeletal structures in living and fixed cultured animal cells and actively streaming algal cells. Actin binding specificity was demon- strated by competitive binding experiments and comparative staining of well-known structures. Large populations of living animal cells in culture were readily stained by using a relatively mild lysolecithin permeabilization procedure facilitated by the small molecular size of the label. Actin in animal cells was stained in stress fibers, ruffles, the cellular geodome, and in diffuse appearing distributions apparently associated with the plasma membrane. Staining of actin cables in algae with ni- trobenzoxadiazole (NBD)Phallacidin did not inhibit cytoplas- mic streaming. NBD-Phallacidin provides a convenient actin- specific fluorescent label for cellular cytoskeletal structures with promise for use in studies of actin dynamics in living sys- tems. To pographical fluorescence microscopy images of the major features of the cellular cytoskeleton have advanced our knowledge of cytoskeletal structures during the last few years. Labeling of fixed cells by indirect immunofluorescence with antiactin antibodies (1, 2) or by fluorescent heavy meromyosin (3) has been used to study microfilaments and their relationship with other cytoskeletal components. More recently, microin- jection of fluorescent actin has been used to study these struc- tures in living cells (4-6). Here we report the development and application of an al- ternative fluorescent marker for cellular F-actin. It is applicable to living cells and thereby offers potential for observing the dynamics of cellular processes. We first outline the synthesis of the fluorescent derivative of Phallacidin. Next we demon- strate its specificity and applicability by three illustrative studies. In the first, images of the actin cytoskeleton of fixed tissue culture fibroblasts provide familiar structures for con- formation of specificity and quality of staining. Second, pre- liminary observations of living animal cells in culture confirm the practicability of incorporating the actin marker into living functioning cells by simple permeabilization procedures and suggest some of the possibilities for observing the dynamics of cytoskeletal processes. Third, we present an application in which the actin filaments associated with the rotational cyto- plasmic streaming in the alga Chara australis are observed without inhibition of streaming in perfused living cells. We sought a fluorescent marker for actin that could be in- troduced conveniently into large populations of living cells,

  • fluorescence staining of the actin cytoskeleton in living cells with 7 nitrobenz 2 oxa 1 3 diazole Phallacidin Phallacidin phalloidin immunofluorescence cytoplasmic streaming chara australis
    2016
    Co-Authors: Larry S Barak, R Rogers, Eugene A Nothnagelt, W W Webbt
    Abstract:

    An active fluorescent derivative of the actin- binding mushroom toxin Phallacidin has been synthesized. Convenient methods were developed to stain actin cytoskeletal structures in living and fixed cultured animal cells and actively streaming algal cells. Actin binding specificity was demon- strated by competitive binding experiments and comparative staining of well-known structures. Large populations of living animal cells in culture were readily stained by using a relatively mild lysolecithin permeabilization procedure facilitated by the small molecular size of the label. Actin in animal cells was stained in stress fibers, ruffles, the cellular geodome, and in diffuse appearing distributions apparently associated with the plasma membrane. Staining of actin cables in algae with ni- trobenzoxadiazole (NBD)Phallacidin did not inhibit cytoplas- mic streaming. NBD-Phallacidin provides a convenient actin- specific fluorescent label for cellular cytoskeletal structures with promise for use in studies of actin dynamics in living sys- tems. To pographical fluorescence microscopy images of the major features of the cellular cytoskeleton have advanced our knowledge of cytoskeletal structures during the last few years. Labeling of fixed cells by indirect immunofluorescence with antiactin antibodies (1, 2) or by fluorescent heavy meromyosin (3) has been used to study microfilaments and their relationship with other cytoskeletal components. More recently, microin- jection of fluorescent actin has been used to study these struc- tures in living cells (4-6). Here we report the development and application of an al- ternative fluorescent marker for cellular F-actin. It is applicable to living cells and thereby offers potential for observing the dynamics of cellular processes. We first outline the synthesis of the fluorescent derivative of Phallacidin. Next we demon- strate its specificity and applicability by three illustrative studies. In the first, images of the actin cytoskeleton of fixed tissue culture fibroblasts provide familiar structures for con- formation of specificity and quality of staining. Second, pre- liminary observations of living animal cells in culture confirm the practicability of incorporating the actin marker into living functioning cells by simple permeabilization procedures and suggest some of the possibilities for observing the dynamics of cytoskeletal processes. Third, we present an application in which the actin filaments associated with the rotational cyto- plasmic streaming in the alga Chara australis are observed without inhibition of streaming in perfused living cells. We sought a fluorescent marker for actin that could be in- troduced conveniently into large populations of living cells,