Identification of alpha-cardiac myosin heavy chain mRNA and protein in extraocular muscle of the adult rabbit

Rushbrook, Julie Ivory; Weiss, Carlos O.; Ko, Kyung Ae; Feuerman, Miriam H.; Carleton, S; Ing, A.; Jacoby, J.

doi:10.1007/bf00121157

Cited by 50 publications

(39 citation statements)

References 41 publications

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“…We are the first to show that the human masseter fibers also contain MHC-ton that coexists with type IIa MHC isoform. The MHC-␣ is coexpressed with type I MHC isoform in the MH muscle (present study), diaphragm (Hamalainen and Pette, 1997), masseter (Bredman et al, 1991;Kwa et al, 1995), and extraocular muscles (Rushbrook et al, 1994), or with type IIa MHC isoform in masseter (Kwa et al, 1995;present study). In contrast, the MHC-neo coexist with IIa and IIx MHC isoforms in the MH muscle (present study), or with type I MHC (Butler-Browne et al, 1988; present study), type IIx MHC (present study), and type IIA, IIB, and IIC fibers (Butler-Browne et al, 1988) in masseter.…”

Section: Hybrid Fiber Typessupporting

confidence: 54%

“…We termed the fibers with multiple major MHC isoforms as the major/major (or m/m) MHC hybrid fibers. Since the unusual MHC isoforms (MHC-ton, MHC-␣, MHC-emb, and MHC-neo) were generally coexpressed with the major adult MHCs (Mascarello et al, 1982;Schiaffino et al, 1988;Bredman et al, 1991;Rushbrook et al, 1994;Kwa et al, 1995;Hamalainen and Pette, 1997;Korfage et al, 2000; present study), we termed these fibers as the major/unusual (or m/u) MHC hybrid fibers.…”

Section: Mhc-based Muscle Fiber Typingmentioning

confidence: 88%

“…The ␣-cardiac MHC isoform, which is normally expressed in the atrium of the heart, is known to be present in various amounts in some specialized skeletal muscles such as diaphragm (Hamalainen and Pette, 1997), extraocular muscles (Wieczorec et al, 1985;Pedrosa-Domellof et al, 1992;Rushbrook et al, 1994;Rubinstein and Hoh, 2000), and masseter (Bredman et al, 1991;PedrosaDomellof et al, 1992;Stal et al, 1994;Kwa et al, 1995;Korfage et al, 2000) and in the muscle spindles (Michel et al, 1996).…”

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confidence: 99%

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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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Section: Hybrid Fiber Typessupporting

confidence: 54%

Section: Mhc-based Muscle Fiber Typingmentioning

confidence: 88%

mentioning

confidence: 99%

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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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“…For example, human and rabbit masticatory muscles retain cardiac -myosin heavy chain expression (Bredman et al, 1991), as do EOMs in rabbits (Rushbrook et al, 1994). However, cardiac -myosin heavy chain is not expressed in the jaw muscles of the rat (Kawai et al, 2009).…”

Section: Neck Muscles: a Transition Zonementioning

confidence: 99%

An eye on the head: the development and evolution of craniofacial muscles

Kuratani²,

2011

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SummarySkeletal muscles exert diverse functions, enabling both crushing with great force and movement with exquisite precision. A remarkably distinct repertoire of genes and ontological features characterise this tissue, and recent evidence has shown that skeletal muscles of the head, the craniofacial muscles, are evolutionarily, morphologically and molecularly distinct from those of the trunk. Here, we review the molecular basis of craniofacial muscle development and discuss how this process is different to trunk and limb muscle development. Through evolutionary comparisons of primitive chordates (such as amphioxus) and jawless vertebrates (such as lampreys) with jawed vertebrates, we also provide some clues as to how this dichotomy arose.

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“…MHC protein is a product of a multigene family. At present, nine isoforms are identified as skeletal muscle MHC isoforms at both the protein and mRNA levels; MHCemb (embryonic), MHCneo (neonatal), MHCI (MHCI,3), MHCIIa, MHCIIx (or MHCIId), MHCIIb, MHCeo (extraocular), MHCm (masticatory or mandibular), and MHCa (a-cardiac-like) [19,62,69,94]. Among them, the major isoforms in adult skeletal muscles are MHCI, MHCIIa, and MHCIIb.…”

Section: Mhc Isoform Of Muscle Fibermentioning

confidence: 99%