Muscle Fiber Types: How Many and What Kind?

Brooke, Michael H.; Kaiser, Kenneth K.

doi:10.1001/archneur.1970.00480280083010

Cited by 1,971 publications

(1,044 citation statements)

References 15 publications

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“…As SDH is an integral component of the citric acid cycle, strongly positive fibres are classified as oxidative fibres. Another commonly cited histochemical staining method depends on the overall myosin adenosine triphosphatase (ATPase) activity in each fibre (Brooke and Kaiser, 1970;Bancroft and Gamble, 2002). Myosin ATPase activity originates from myosin heavy chain (MyHC), the principal sacromeric protein component of the thick myofilament.…”

Section: Fibre Types: Coordinated Isoform-specific Expressionmentioning

confidence: 99%

Key signalling factors and pathways in the molecular determination of skeletal muscle phenotype

Chang

2007

Animal

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The molecular basis and control of the biochemical and biophysical properties of skeletal muscle, regarded as muscle phenotype, are examined in terms of fibre number, fibre size and fibre types. A host of external factors or stimuli, such as ligand binding and contractile activity, are transduced in muscle into signalling pathways that lead to protein modifications and changes in gene expression which ultimately result in the establishment of the specified phenotype. In skeletal muscle, the key signalling cascades include the Ras-extracellular signal regulated kinase-mitogen activated protein kinase (Erk-MAPK), the phosphatidylinositol 3 0 -kinase (PI3K)-Akt1, p38 MAPK, and calcineurin pathways. The molecular effects of external factors on these pathways revealed complex interactions and functional overlap. A major challenge in the manipulation of muscle of farm animals lies in the identification of regulatory and target genes that could effect defined and desirable changes in muscle quality and quantity. To this end, recent advances in functional genomics that involve the use of micro-array technology and proteomics are increasingly breaking new ground in furthering our understanding of the molecular determinants of muscle phenotype.

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Section: Fibre Types: Coordinated Isoform-specific Expressionmentioning

confidence: 99%

Key signalling factors and pathways in the molecular determination of skeletal muscle phenotype

Chang

2007

Animal

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“…Among a number of systems advocated for classifying skeletal muscle fiber types, the classification scheme proposed by Brooke and Kaiser (1970) has gained wide acceptance (Burke, 1981;Dubowitz, 1985). This system is based on the myofibrillar ATPase (mATPase) reaction after preincubation at various pH values and differentiates muscle fibers into four types: I, IIA, IIB, and IIC.…”

Section: Fiber-type Classification For Cranial Musclesmentioning

confidence: 99%

Adult human mylohyoid muscle fibers express slow‐tonic, α‐cardiac, and developmental myosin heavy‐chain isoforms

Wang

et al. 2004

Anat. Rec.

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Some adult cranial muscles have been reported to contain unusual myosin heavy-chain (MHC) isoforms (i.e., slow-tonic, ␣-cardiac, embryonic, and neonatal), which exhibit distinct contractile properties. In this study, adult human mylohyoid (MH) muscles obtained from autopsies were investigated to detect the unusual MHC isoforms. For comparison, the biceps brachii and masseter muscles of the same subjects were also examined. Serial cross-sections from the muscles studied were incubated with a panel of isoform-specific anti-MHC monoclonal antibodies that distinguish major and unusual MHC isoforms. On average, the slow type I and fast type II MHC-containing fibers in the MH muscle accounted for 54% and 46% of the fibers, respectively. In contrast to limb and trunk muscles, the adult human MH muscle was characterized by a large proportion of hybrid fibers (85%) and a small percentage of pure fibers (15%; P Ͻ 0.01). Of the fast fiber types, the proportion of the type IIa MHC-containing fibers (92%) was much greater than that of the type IIx MHC-containing fibers (8%; P Ͻ 0.01). Our data demonstrated that the adult human MH fibers expressed the unusual MHC isoforms that were also identified in the masseter, but not in the biceps brachii. These isoforms were demonstrated by immunocytochemistry and confirmed by electrophoretic immunoblotting. Fiber-to-fiber comparisons showed that the unusual MHC isoforms were coexpressed with the major MHC isoforms (i.e., MHCI, IIa, and IIx), thus forming various major/unusual (or m/u) MHC hybrid fiber types. Interestingly, the unusual MHC isoforms were expressed in a fiber type-specific manner. The slow-tonic and ␣-cardiac MHC isoforms were coexpressed predominantly with slow type I MHC isoform, whereas the developmental MHC isoforms (i.e., embryonic and neonatal) coexisted primarily with fast type IIa MHC isoform. There were no MH fibers that expressed exclusively unusual MHC isoforms. Approximately 81% of the slow type I MHC-containing fibers expressed slow-tonic and ␣-cardiac MHC isoforms, whereas 80% of the fast type IIa MHC-containing fibers expressed neonatal MHC isoform. The m/u hybrid fibers (82% of the total fiber population) were found to constitute the predominant fiber types in the adult human MH muscle. At least seven m/u MHC hybrid fiber types were identified in the adult human MH muscle. The most common m/u hybrid fiber types were found to be the MHCI/slow-tonic/␣-cardiac and MHCIIa/neonatal, which accounted for 39% and 33% of the total fiber population, respectively. The multiplicity of MHC isoforms in the adult MH fibers is believed to be related to embryonic origin, innervation pattern, and unique functional requirements.

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“…Based only on the myosin ATPase activity (Brooke and Kaiser, 1970) used to characterize mammalian and avian fiber types, it is difficult to identify all the Xenopus fiber types. The fiber type terminology used for higher vertebrates (i.e., type IIB, IIA, IIX, and I fibers) also seems difficult to apply in the case of anuran muscles.…”

Section: Muscle Fiber Typesmentioning

confidence: 99%

Xenopusmuscle development: From primary to secondary myogenesis

Chanoine

Hardy

2002

Developmental Dynamics

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Xenopus myogenesis is characterized by specific features, different from those of mammalian and avian systems both at the cellular level and in gene expression patterns. During early embryogenesis, after the initial molecular signals inducing mesoderm, the myogenic determination factors XMyoD and XMyf-5 are activated in presomitic mesoderm in response to mesoderm-inducing factors. After these first inductions of the myogenic program, forming muscles in Xenopus can have different destinies, some of these resulting in cell death before adulthood. In particular, it is quite characteristic of this species that, during metamorphosis, the primary myotomal myofibers completely die and are progressively replaced by secondary "adult" multinucleated myofibers. This feature offers the unique opportunity to totally separate the molecular analysis of these two distinct types of myogenesis. The aim of this review is to summarize our knowledge on the cellular and molecular events as well as the epigenetic regulations involved in the construction of Xenopus muscles during development. Developmental Dynamics 226:12-23, 2003.

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Muscle Fiber Types: How Many and What Kind?

Abstract: (Fig 1 and 2)

Cited by 1,971 publications

References 15 publications

Key signalling factors and pathways in the molecular determination of skeletal muscle phenotype

Key signalling factors and pathways in the molecular determination of skeletal muscle phenotype

Adult human mylohyoid muscle fibers express slow‐tonic, α‐cardiac, and developmental myosin heavy‐chain isoforms

Xenopusmuscle development: From primary to secondary myogenesis

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