Fine structure of the myotendinous junction and ?terminal coupling? in the skeletal muscle of the lamprey,Lampetra japonica

1975 ◽  
Vol 182 (3) ◽  
pp. 321-337 ◽  
Author(s):  
Taisuke Nakao
Keyword(s):  
Skeletal Muscle ◽  
Fine Structure ◽  
Myotendinous Junction ◽  
Lampetra Japonica

Rapid and reciprocal regulation of tenascin-C and tenascin-Y expression by loading of skeletal muscle

2000 ◽  
Vol 113 (20) ◽  
pp. 3583-3591 ◽  
Author(s):  
M. Fluck ◽  
V. Tunc-Civelek ◽  
M. Chiquet
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Matrix ◽  
Tensile Stress ◽  
Muscle Fibers ◽  
Myotendinous Junction ◽  
Left Wing ◽  
C Protein ◽  
Tenascin C ◽  
Mrna Induction

Tenascin-C and tenascin-Y are two structurally related extracellular matrix glycoproteins that in many tissues show a complementary expression pattern. Tenascin-C and the fibril-associated minor collagen XII are expressed in tissues bearing high tensile stress and are located in normal skeletal muscle, predominantly at the myotendinous junction that links muscle fibers to tendon. In contrast, tenascin-Y is strongly expressed in the endomysium surrounding single myofibers, and in the perimysial sheath around fiber bundles. We previously showed that tenascin-C and collagen XII expression in primary fibroblasts is regulated by changes in tensile stress. Here we have tested the hypothesis that the expression of tenascin-C, tenascin-Y and collagen XII in skeletal muscle connective tissue is differentially modulated by mechanical stress in vivo. Chicken anterior latissimus dorsi muscle (ALD) was mechanically stressed by applying a load to the left wing. Within 36 hours of loading, expression of tenascin-C protein was ectopically induced in the endomysium along the surface of single muscle fibers throughout the ALD, whereas tenascin-Y protein expression was barely affected. Expression of tenascin-C protein stayed elevated after 7 days of loading whereas tenascin-Y protein was reduced. Northern blot analysis revealed that tenascin-C mRNA was induced in ALD within 4 hours of loading while tenascin-Y mRNA was reduced within the same period. In situ hybridization indicated that tenascin-C mRNA induction after 4 hours of loading was uniform throughout the ALD muscle in endomysial fibroblasts. In contrast, the level of tenascin-Y mRNA expression in endomysium appeared reduced within 4 hours of loading. Tenascin-C mRNA and protein induction after 4–10 hours of loading did not correlate with signs of macrophage infiltration. Tenascin-C protein decreased again with removal of the load and nearly disappeared after 5 days. Furthermore, loading was also found to induce expression of collagen XII mRNA and protein, but to a markedly lower level, with slower kinetics and only partial reversibility. The results suggest that mechanical loading directly and reciprocally controls the expression of extracellular matrix proteins of the tenascin family in skeletal muscle.

Fine Structure of Aging Skeletal Muscle

1981 ◽  
pp. 333-346 ◽  
Author(s):  
S. A. Shafiq ◽  
S. Lewis ◽  
B. Leung ◽  
H. S. Schutta
Keyword(s):  
Skeletal Muscle ◽  
Fine Structure

scholarly journals The myotendinous junction marker collagen XXII enables zebrafish postural control learning and optimal swimming performance through its force transmission activity

2021 ◽  
Author(s):  
Marilyne Malbouyres ◽  
Alexandre Guiraud ◽  
Christel Lefrancois ◽  
Melanie Salamito ◽  
Pauline Nauroy ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Swimming Performance ◽  
Muscle Performance ◽  
Myotendinous Junction ◽  
Force Transmission ◽  
Skeletal Muscle Function ◽  
Gene Ablation ◽  
Class 1 ◽  
Control Learning ◽  
Degrees Of Severity

Although the myotendinous junction (MTJ) is essential for skeletal muscle integrity, its contribution to skeletal muscle function remains largely unknown. Here, we show that CRISPR-Cas9-mediated gene ablation of the MTJ marker col22a1 in zebrafish identifies two distinctive phenotypic classes: class 1 individuals reach adulthood with no overt muscle phenotype while class 2 display severe movement impairment and eventually dye before metamorphosis. Yet mutants that are unequally affected are all found to display defective force transmission attributed to a loss of ultrastructural integrity of the MTJ and myosepta, though with distinct degrees of severity. The behavior-related consequences of the resulting muscle weakness similarly reveal variable phenotypic expressivity. Movement impairment at the critical stage of swimming postural learning eventually causes class 2 larval death by compromising food intake while intensive exercise is required to uncover a decline in muscle performance in class 1 adults. By confronting MTJ gene expression compensation and structural, functional and behavioral insights of MTJ dysfunction, our work unravels variable expressivity of col22a1 mutant phenotype. This study also underscores COL22A1 as a candidate gene for myopathies associated with dysfunctional force transmission and anticipates a phenotypically heterogeneous disease.

scholarly journals Single-nucleus RNA-seq identifies transcriptional heterogeneity in multinucleated skeletal myofibers

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael J. Petrany ◽  
Casey O. Swoboda ◽  
Chengyi Sun ◽  
Kashish Chetal ◽  
Xiaoting Chen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Neuromuscular Junction ◽  
Postnatal Development ◽  
Rna Sequencing ◽  
Cell Types ◽  
Myotendinous Junction ◽  
Rna Seq ◽  
Muscle Biology ◽  
Single Nucleus ◽  
Aging Muscle

AbstractWhile the majority of cells contain a single nucleus, cell types such as trophoblasts, osteoclasts, and skeletal myofibers require multinucleation. One advantage of multinucleation can be the assignment of distinct functions to different nuclei, but comprehensive interrogation of transcriptional heterogeneity within multinucleated tissues has been challenging due to the presence of a shared cytoplasm. Here, we utilized single-nucleus RNA-sequencing (snRNA-seq) to determine the extent of transcriptional diversity within multinucleated skeletal myofibers. Nuclei from mouse skeletal muscle were profiled across the lifespan, which revealed the presence of distinct myonuclear populations emerging in postnatal development as well as aging muscle. Our datasets also provided a platform for discovery of genes associated with rare specialized regions of the muscle cell, including markers of the myotendinous junction and functionally validated factors expressed at the neuromuscular junction. These findings reveal that myonuclei within syncytial muscle fibers possess distinct transcriptional profiles that regulate muscle biology.

scholarly journals The subcellular distribution of dystrophin in mouse skeletal, cardiac, and smooth muscle.

1991 ◽  
Vol 115 (2) ◽  
pp. 411-421 ◽  
Author(s):  
T J Byers ◽  
L M Kunkel ◽  
S C Watkins
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Plasma Membrane ◽  
Cardiac Muscle ◽  
Striated Muscle ◽  
Adherens Junctions ◽  
Myotendinous Junction ◽  
Elevated Concentration ◽  
Western Blots ◽  
Functional Roles

We use a highly specific and sensitive antibody to further characterize the distribution of dystrophin in skeletal, cardiac, and smooth muscle. No evidence for localization other than at the cell surface is apparent in skeletal muscle and no 427-kD dystrophin labeling was detected in sciatic nerve. An elevated concentration of dystrophin appears at the myotendinous junction and the neuromuscular junction, labeling in the latter being more intense specifically in the troughs of the synaptic folds. In cardiac muscle the distribution of dystrophin is limited to the surface plasma membrane but is notably absent from the membrane that overlays adherens junctions of the intercalated disks. In smooth muscle, the plasma membrane labeling is considerably less abundant than in cardiac or skeletal muscle and is found in areas of membrane underlain by membranous vesicles. As in cardiac muscle, smooth muscle dystrophin seems to be excluded from membrane above densities that mark adherens junctions. Dystrophin appears as a doublet on Western blots of skeletal and cardiac muscle, and as a single band of lower abundance in smooth muscle that corresponds most closely in molecular weight to the upper band of the striated muscle doublet. The lower band of the doublet in striated muscle appears to lack a portion of the carboxyl terminus and may represent a dystrophin isoform. Isoform differences and the presence of dystrophin on different specialized membrane surfaces imply multiple functional roles for the dystrophin protein.

Fine structure and lectin histochemistry of the apical surface of the free neuromast of Lampetra japonica

1994 ◽  
Vol 276 (2) ◽  
pp. 245-252
Author(s):  
Yukio Katori ◽  
Tomonori Takasaka ◽  
Makoto Ishikawa ◽  
Akira Tonosaki
Keyword(s):  
Fine Structure ◽  
Lectin Histochemistry ◽  
Apical Surface ◽  
Lampetra Japonica

The Fine structure of mammalian skeletal muscle

1949 ◽  
Vol 84 (2) ◽  
pp. 175-200 ◽  
Author(s):  
Daniel C. Pease ◽  
Richard F. Baker
Keyword(s):  
Skeletal Muscle ◽  
Fine Structure ◽  
Mammalian Skeletal Muscle
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