Cytoskeletal elements in insect sensilla

Little is known about the temporal expression of extracellular matrix components (ECM) and its receptors during development of the heart. Recent reports have shown that ECM components undergo both qualitative and quantitative changes during development, and it is believed that ECM components are important in the regulation of cell migration and cell:cell and cell:ECM recognition and adhesion.Integrins are transmembrane glycoproteins which bind several ECM components on their external face and cytoskeletal elements on the cytoplasmic face. Laminin is a basement membrane component which has been recognized as an important site for cell adhesion. Both the integrins and laminin are expressed early in development and continue to be expressed in the adult heart. With their documented roles in cell recognition, and cell:cell and cell:ECM migration and adhesion these proteins appear to be important components in development of the heart, and their temporal expression may play a pivotal role in morphogenesis and myofibrillogenesis of the heart.

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SEM of non-coated hepatocellular cytoskeleton of perfused livers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111641 ◽

1984 ◽

Vol 42 ◽

pp. 306-307

Author(s):

S.W. French ◽

N.C. Benson ◽

C. Davis-Scibienski

Keyword(s):

Ambient Temperature ◽

Critical Point ◽

Protease Inhibitors ◽

Metal Deposition ◽

Heat Damage ◽

Detergent Extraction ◽

Cytoskeletal Elements ◽

Triton X ◽

Excised Tissue

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.

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Alzheimer's Paired Helical Filaments Contain Insoluble Cytoskeletal Elements

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100120370 ◽

1985 ◽

Vol 43 ◽

pp. 748-751

Author(s):

P. Gambetti ◽

G. Perry ◽

L. Autillo-Gambetti

Keyword(s):

Paired Helical Filaments ◽

Microscope Level ◽

Antigenic Determinants ◽

Light Microscope Level ◽

Neuronal Cytoskeleton ◽

Ionic Detergent ◽

Associated Proteins ◽

Pathologic Lesions ◽

10 Nm Filaments ◽

Cytoskeletal Elements

Neurofibrillary tangles (NFT) are one of the major pathologic lesions of Alzheimer's disease. These neuronal inclusions are predominantly composed of paired helical filaments (PHF), which consist of two 10 nm filaments winding around each other with an approximately 80 nm periodicity. Besides PHF, NFT comprise also 15 nm filaments, 10 nm filaments which are probably neurofilaments, microtubules and granular material. At variance with the neuronal cytoskeleton, PHF are insoluble in ionic detergent.Studies at the light microscope level have shown that NFT have unique antigenic determinants as well as determinants in common with elements of the normal neuronal cytoskeleton such as neurofilaments and microtubule-associated proteins. The present study uses immunocytochemistry and cytochemistry at the electron microscope level to assess which NFT component contains these determinants and whether these antigenic determinants are soluble in an ionic detergent.

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Three-Dimensional Subcellular Organization of Hepatocytes in Intact Liver: Simultaneous Visualization of Cytoskeletal and Membrane Markers by Confocal Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163903 ◽

1996 ◽

Vol 54 ◽

pp. 288-289

Author(s):

Greg V. Martin ◽

Ann L. Hubbard

Keyword(s):

Three Dimensional ◽

Integral Membrane Proteins ◽

Polarized Secretion ◽

Microscope Images ◽

Computer Aided ◽

Intracellular Organelles ◽

Cytoskeletal Elements ◽

Simultaneous Visualization

The microtubule (MT) cytoskeleton is necessary for many of the polarized functions of hepatocytes. Among the functions dependent on the MT-based cytoskeleton are polarized secretion of proteins, delivery of endocytosed material to lysosomes, and transcytosis of integral plasma membrane (PM) proteins. Although microtubules have been shown to be crucial to the establishment and maintenance of functional and structural polarization in the hepatocyte, little is known about the architecture of the hepatocyte MT cytoskeleton in vivo, particularly with regard to its relationship to PM domains and membranous organelles. Using an in situ extraction technique that preserves both microtubules and cellular membranes, we have developed a protocol for immunofluorescent co-localization of cytoskeletal elements and integral membrane proteins within 20 µm cryosections of fixed rat liver. Computer-aided 3D reconstruction of multi-spectral confocal microscope images was used to visualize the spatial relationships among the MT cytoskeleton, PM domains and intracellular organelles.

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Laser scanning confocal microscopic analysis of cytoskeletal and nuclear reorganization in live Drosophila embryos

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146710 ◽

1993 ◽

Vol 51 ◽

pp. 174-175

Author(s):

William Theurkauf

Keyword(s):

Laser Scanning ◽

Microscopic Analysis ◽

Large Cell ◽

Early Embryo ◽

Drosophila Embryo ◽

Cortical Actin ◽

Nuclear Reorganization ◽

Cytoskeletal Elements ◽

Microtubule Structure ◽

Drosophila Embryos

Cell division in eucaryotes depends on coordinated changes in nuclear and cytoskeletal components. In Drosophila melanogaster embryos, the first 13 nuclear divisions occur without cytokinesis. During the final four divisions, nuclei divide in a uniform monolayer at the surface of the embryo. These surface divisions are accompanied by dramatic changes in cortical actin and microtubule structure (Karr and Alberts, 1986), and inhibitor studies indicate that these changes are essential to orderly mitosis (Zalokar and Erk, 1976). Because the early embryo is syncytial, fluorescent probes introduced by microinjection are incorporated in structures associated with all of the nuclei in the blastoderm. In addition, the nuclei divide synchronously every 10 to 20 min. These characteristics make the syncytial blastoderm embryo an excellent system for the analysis of mitotic reorganization of both nuclear and cytoskeletal elements. However, the Drosophila embryo is a large cell, and resolution of cytoskeletal filaments and nuclear structure is hampered by out-of focus signal.

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