scholarly journals Connectin filaments in stretched skinned fibers of frog skeletal muscle.

1984 ◽  
Vol 99 (4) ◽  
pp. 1391-1397 ◽  
Author(s):  
K Maruyama ◽  
H Sawada ◽  
S Kimura ◽  
K Ohashi ◽  
H Higuchi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Electron Microscopic ◽  
Thin Filaments ◽  
Thin Sections ◽  
Cytoskeletal Structure ◽  
Present Information ◽  
Sds Page ◽  
Myosin Filaments ◽  
Elastic Protein ◽  
Passive Stretch

Indirect immunofluorescence microscopy of highly stretched skinned frog semi-tendinous muscle fibers revealed that connectin, an elastic protein of muscle, is located in the gap between actin and myosin filaments and also in the region of myosin filaments except in their centers. Electron microscopic observations showed that there were easily recognizable filaments extending from the myosin filaments to the I band region and to Z lines in the myofibrils treated with antiserum against connectin. In thin sections prepared with tannic acid, very thin filaments connected myosin filaments to actin filaments. These filaments were also observed in myofibrils extracted with a modified Hasselbach-Schneider solution (0.6 M KCl, 0.1 M phosphate buffer, pH 6.5, 2 mM ATP, 2 mM MgCl2, and 1 mM EGTA) and with 0.6 M Kl. SDS PAGE revealed that connectin (also called titin) remained in extracted myofibrils. We suggest that connectin filaments play an important role in the generation of tension upon passive stretch. A scheme of the cytoskeletal structure of myofibrils of vertebrate skeletal muscle is presented on the basis of our present information of connectin and intermediate filaments.

scholarly journals In situ reconstitution of myosin filaments within the myosin-extracted myofibril in cultured skeletal muscle cells.

1982 ◽  
Vol 92 (2) ◽  
pp. 324-332 ◽  
Author(s):  
M Taniguchi ◽  
H Ishikawa
Keyword(s):  
Skeletal Muscle ◽  
Salt Solution ◽  
Muscle Cells ◽  
High Salt ◽  
Skeletal Muscle Cells ◽  
Thin Filaments ◽  
Skeletal Muscle Myosin ◽  
Myosin Filaments ◽  
Glycerinated Muscle

We studied the in situ reconstitution of myosin filaments within the myosin-extracted myofibrils in cultured chick embryo skeletal muscle cells using the electron microscope and polarization microscope. Myosin was first extracted from the myofibrils in glycerinated muscle cells with a high-salt solution containing 0.6 M KCl. When rabbit skeletal muscle myosin was added to the myosin-extracted cells in the high-salt solution, thin filaments in the ghost myofibrils were bound with myosin to form arrowhead complexes. Subsequent dilution of KCl in the myosin solution to 0.1 M resulted in the formation of thick myosin filaments within the myofibrils, increasing the birefringence of the myofibrils. When Mg-ATP was added such myosin-reassembled myofibrils were induced either to form supercontraction bands or to restore the sarcomeric arrangement of thick and thin filaments. Under the polarization microscope, vibrational movement of the myofibrils was seen transiently upon addition of Mg-ATP, often resulting in a regular arrangement of myofibrils in register. These myofibrils, with reconstituted myosin filaments, structurally and functionally resembled the native myofibrils. The findings are discussed with special reference to the myofibril formation in developing muscle cells.

Electron-microscopic structure of denervated skeletal muscle

1969 ◽  
Vol 174 (1035) ◽  
pp. 253-269 ◽  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibres ◽  
Microscopic Structure ◽  
Sectional Area ◽  
Rat Diaphragm ◽  
Denervated Muscle ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Myosin Filaments ◽  
Filament Spacing

(1) An electron-microscopic study was made of normal and denervated muscle fibres in the rat diaphragm. (2) Early after denervation muscle fibres become hypertrophic. The cross-sectional area of the fibres and the number of myofibrils within them are increased. Since filament spacing is not significantly altered, it is concluded that during hypertrophy the number of actin and myosin filaments is increased. (3) A few weeks after denervation the muscle fibres are greatly reduced in size. This atrophy is mainly a consequence of two processes: fragmentation of the muscle fibre, with subsequent degeneration of the fragments; and disintegration of myofilaments.

scholarly journals Extensibility of the myofilaments in vertebrate skeletal muscle as revealed by stretching rigor muscle fibers.

1983 ◽  
Vol 81 (4) ◽  
pp. 531-546 ◽  
Author(s):  
S Suzuki ◽  
H Sugi
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Psoas Muscle ◽  
Thick Filament ◽  
Force Extension ◽  
Electron Microscopic ◽  
Thin Filaments ◽  
Extension Curve ◽  
Electron Microscopic Data ◽  
Vertebrate Skeletal Muscle

The extensibility of the myofilaments in vertebrate skeletal muscle was studied by stretching glycerinated rabbit psoas muscle fibers in rigor state and examining the resulting extension of sarcomere structures under an electron microscope. Although stretches applied to rigor fibers produced a successive yielding of the weakest sarcomeres, the length of the remaining intact sarcomeres in many myofibrils was fairly uniform, being definitely longer than the sarcomeres in the control, nonstretched part of rigor fibers. The stretch-induced increase in sarcomere length was found to be taken up by the extension of the H zone and the I band, whereas the amount of overlap between the thick and thin filaments did not change appreciably with stretches of 10-20%. The thick filament extension in the H zone was localized in the bare regions, whereas the thin filament extension in the I band appeared to take place uniformly along the filament length. No marked increase in the Z-line width was observed even with stretches of 20-30%. These results clearly demonstrate the extensibility of the thick and thin filaments. The possible contribution of the myofilament compliance to the series elastic component (SEC) in vertebrate skeletal muscle fibers is discussed on the basis of the electron microscopic data and the force-extension curve of the SEC in rigor fibers.

scholarly journals Connectin filaments link thick filaments and Z lines in frog skeletal muscle as revealed by immunoelectron microscopy.

1985 ◽  
Vol 101 (6) ◽  
pp. 2167-2172 ◽  
Author(s):  
K Maruyama ◽  
T Yoshioka ◽  
H Higuchi ◽  
K Ohashi ◽  
S Kimura ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Microscopic Study ◽  
Immunoelectron Microscopy ◽  
Striated Muscle ◽  
Polyclonal Antibodies ◽  
Frog Skeletal Muscle ◽  
Junction Region ◽  
Thick Filaments ◽  
Myosin Filaments ◽  
Elastic Protein

In an earlier study connectin, an elastic protein of striated muscle, was found to be associated with "gap filaments" originating from the thick filaments in the myofibril, but it was not clear whether it extends to Z lines or not (Maruyama, K., H. Sawada, S. Kimura, K. Ohashi, H. Higuchi, and Y. Umazume, 1984, J. Cell Biol., 99:1391-1397). In the present immunoelectron microscopic study using polyclonal antibodies against native connectin, we have concluded that the connectin structures are directly linked to Z lines from the thick (myosin) filaments in myofibrils of skinned fibers of frog skeletal muscle. There were five distinct antibody-binding stripes in each half of the A band and two stripes in the A-I junction region. Deposits of antibodies were recognized in I bands and Z lines. We suggest that connectin filaments run alongside the thick filaments, starting from a region approximately 0.15 micron from the center of the A band.

scholarly journals MITOSIS AND INTERMEDIATE-SIZED FILAMENTS IN DEVELOPING SKELETAL MUSCLE

1968 ◽  
Vol 38 (3) ◽  
pp. 538-555 ◽  
Author(s):  
H. Ishikawa ◽  
R. Bischoff ◽  
H. Holtzer
Keyword(s):  
Skeletal Muscle ◽  
Chick Embryos ◽  
Myogenic Cells ◽  
Thin Filaments ◽  
New Class ◽  
Single Section ◽  
Myosin Filaments ◽  
Obvious Association ◽  
Mitotic Inhibitors ◽  
Cells Cultured

A new class of filaments intermediate in diameter between actin and myosin filaments has been demonstrated in skeletal muscle cells cultured from chick embryos. These filaments, which account for the majority of free filaments, average 100 A in diameter. They may run for more than 2 µ in a single section and can be distinguished in size and appearance from the thick and thin filaments assembled into myofibrils. The 100-A filaments are seen scattered throughout the sarcoplasm at all stages of development and show no obvious association with the myofibrils. The 100-A filaments are particularly conspicuous in myotubes fragmented by the mitotic inhibitors, colchicine and Colcemid. In addition, filaments similar in size and appearance to those found in myotubes are present in fibroblasts, chondrocytes, and proliferating mononucleated myoblasts. The 100-A filaments are present in cells arrested in metaphase by mitotic inhibitors. Definitive thick (about 150 A) or thin (about 60 A) myofilaments are not found in skeletal myogenic cells arrested in metaphase. Myogenic cells arrested in metaphase do not bind fluorescein-labeled antibody directed against myosin or actin. For these reasons, it is concluded that not all "thin" filaments in myogenic cells are uniquely associated with myogenesis.

scholarly journals Interactions between actin and myosin filaments in skeletal muscle visualized in frozen-hydrated thin sections

1989 ◽  
Vol 55 (4) ◽  
pp. 713-724 ◽  
Author(s):  
B.L. Trus ◽  
A.C. Steven ◽  
A.W. McDowall ◽  
M. Unser ◽  
J. Dubochet ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Thin Sections ◽  
Myosin Filaments

Force Modulation Elasticity Mapping of Plastic-embedded, Thin-sectioned Skeletal Muscle

2001 ◽  
Vol 7 (1) ◽  
pp. 32-38
Author(s):  
Boris B. Akhremitchev ◽  
Henry G. Brown ◽  
Scott R. Graner ◽  
Gilbert C. Walker
Keyword(s):  
Skeletal Muscle ◽  
Atomic Force Microscopy ◽  
Biological Material ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Force Microscopy ◽  
Force Modulation ◽  
Atomic Force ◽  
The Difference ◽  
Microscopic Techniques

AbstractWe have been researching the capability of atomic force microscopy to reveal nontopographic properties of tissue embedded in plastic and sectioned with standard electron microscopic techniques. We present topography and elasticity maps of plastic-embedded, thin sections of muscle tissue. The images show topography correlated with the normal repeating structure of the sarcomere. Elasticity mapping using force modulation revealed contrast between the actin- and myosin-rich areas. We attribute the observed contrast in elasticity to the difference in local concentrations of biological material in embedding plastic.

Myofilament overlap in swimming carp. I. Myofilament lengths of red and white muscle

1991 ◽  
Vol 260 (2) ◽  
pp. C283-C288 ◽  
Author(s):  
A. A. Sosnicki ◽  
K. E. Loesser ◽  
L. C. Rome
Keyword(s):  
Actin Filaments ◽  
Sarcomere Length ◽  
White Muscle ◽  
Frog Muscle ◽  
Myosin Filament ◽  
Thin Filaments ◽  
Thin Sections ◽  
Myosin Filaments ◽  
Tension Curve ◽  
Red And White Muscles

To assess myofilament overlap during locomotion, we estimated the length of myosin and actin filaments in axial red and white muscle of carp. Myosin filament lengths were 1.52 +/- 0.009 and 1.50 +/- 0.037 micron (means +/- SD) in the red and white muscle, respectively, as measured from thin sections. After correction for shrinkage (using the troponin-based 385-A axial periodicity), thin filaments were 0.96 +/- 0.009 and 0.97 +/- 0.023 micron in the red and white muscles, respectively. Filaments were also isolated from the white muscle and negatively stained. Myosin filaments were 1.56 +/- 0.025 microns, and actin filaments were 0.99 +/- 0.024 micron in length. The data from thin sections and isolated filaments agreed within 2% for actin and 4% for myosin filaments. The number of actin filament periods (24 for the red and white muscle) and the length of the filaments are the same as in frog. This suggests that the classic sarcomere length-tension curve of frog muscle may be used to estimate the functional properties of carp red and white muscle.

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

1973 ◽  
Vol 31 ◽  
pp. 574-575
Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy
Keyword(s):  
Cellular Localization ◽  
Direct Evidence ◽  
Azotobacter Vinelandii ◽  
Intracellular Localization ◽  
Protein Component ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fe Protein ◽  
Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

Sign in / Sign up

Export Citation Format

Share Document