Myosin isoforms, muscle fiber types, and transitions

  title={Myosin isoforms, muscle fiber types, and transitions},
  author={Dirk Pette and Robert S. Staron},
  journal={Microscopy Research and Technique},
  • D. Pette, R. Staron
  • Published 15 September 2000
  • Biology
  • Microscopy Research and Technique
Skeletal muscle is an extremely heterogeneous tissue composed of a variety of fast and slow fiber types and subtypes. Moreover, muscle fibers are versatile entities capable of adjusting their phenotypic properties in response to altered functional demands. Major differences between muscle fiber types relate to their myosin complement, i.e., isoforms of myosin light and heavy chains. Myosin heavy chain (MHC) isoforms appear to represent the most appropriate markers for fiber type delineation. On… 

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Contractile protein content reflects myosin heavy-chain isoform gene expression.

Data show differences in MyHC gene expression across various porcine muscles and suggest that expression of these genes is reflective of the type of myosin contained within the muscle.

Mouse transgenic lines that selectively label type I, type IIa, and types IIX+B skeletal muscle fibers

Transgenic mouse lines in which Type I, Type IIA, and Type IIX+B fibers can be selectively labeled with distinguishable fluorophores are generated and used for motor unit reconstruction and live imaging of nerve‐dependent alterations in fiber type.

Coupled expression of troponin T and troponin I isoforms in single skeletal muscle fibers correlates with contractility.

Results demonstrate distinct but coordinated regulation of troponin and myosin isoform expression in skeletal muscle and their contribution to the contractile properties of muscle.

Hybrid fibres under slow-to-fast transformations: expression is of myosin heavy and light chains in rat soleus muscle

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Transitions of muscle fiber phenotypic profiles

This brief review summarizes the current understanding of the delineation of fiber types, modulations of their phenotypic profiles as induced under various conditions, and potential mechanisms involved in these transitions.

The continuum of hybrid IIX/IIB fibers in normal mouse muscles: MHC isoform proportions and spatial distribution within single fibers.

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Advanced Fiber Type-Specific Protein Profiles Derived from Adult Murine Skeletal Muscle

A protocol was established in which myosin heavy chain isoform immunolabeled muscle fibers were laser microdissected and separately investigated by mass spectrometry to develop advanced proteomic profiles of all murine skeletal muscle fiber types, revealing unique fiber type protein profiles.

Skeletal muscule fiber types in C57BL6J mice

The aim of this study was to examine the fiber composition of the soleus (SOL), extensor digitorum longus (EDL), tibialis anterior (TA) and gastrocnemius (GAS) muscles of C57BL6J mice using histochemical and biochemical methods.



Patterns of myosin isoforms in mammalian skeletal muscle fibres

The present article attempts to combine existing information on the distribution of fast and slow myosin isoforms in histochemically distinct muscle fibres to create a spectrum of fibre types.

Mammalian skeletal muscle fiber type transitions.

Two functionally distinct myosin heavy chain isoforms in slow skeletal muscle fibres

Coordinate changes of myosin light and heavy chain isoforms during forced fiber type transitions in rabbit muscle.

In conclusion, fiber type specific programs that normally coordinate the expression of myofibrillar protein isoforms seem to be maintained during fiber type transitions, giving rise to the appearance of hybrid fibers under the conditions of forced fiber type conversion.

Myosin isoforms in mammalian skeletal muscle.

Skeletal muscles of different mammalian species contain four major myosin heavy-chain (MHC) isoforms: the "slow" or beta-MHC and the three "fast" IIa-, IIx-, and IIb-MHCs; and three major myosin

Variations in contractile properties of rabbit single muscle fibres in relation to troponin T isoforms and myosin light chains.

It appears that different isoforms of troponin T are responsible for a slightly higher Ca2+ sensitivity of tension development in the high‐velocity fibres compared to the intermediate fibres, and a much greater diversity exists among single fibres from adult mammalian skeletal muscle than previously recognized.

Molecular diversity of myofibrillar proteins: gene regulation and functional significance.

The pattern of isogene expression varies during muscle development in relation to the different origin of myogenic cells and primary/secondary fiber generations and is affected by neural and hormonal influences.

Expression of myosin heavy chain isoforms in stimulated fast and slow rat muscles

The expression of 4 myosin heavy chain (MHC) isoforms was analyzed in the rat soleus (SOL) and extensor digitorum longus (EDL) muscles after denervation and chronic electric stimulation and coexistence of different MHC types in the same fiber was frequently observed in stimulated muscles.

Force‐velocity relations and myosin heavy chain isoform compositions of skinned fibres from rat skeletal muscle.

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