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Stephen H. Devoto - One of the best experts on this subject based on the ideXlab platform.
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The Development of Muscle Fiber Type Identity in Zebrafish
2009Co-Authors: Stephen H. DevotoAbstract:Cranial skeletal Muscles underlie breathing, eating, and eye movements. In most animals, at least two types of Muscle fibers underlie these critical functions: fast and Slow Muscle fibers. We describe here the anatomical distribution of Slow and fast twitch Muscle in the zebrafish (Danio rerio) head in the adult and at an early larval stage just after feeding has commenced. We found that all but one of the cranial Muscles examined contain both Slow and fast Muscle fibers, but the relative proportion of Slow Muscle in each varies considerably. As in the trunk, Slow Muscle fibers are found only in an anatomically restricted zone of each Muscle, usually on the periphery. The relative proportion of Slow and fast Muscle in each cranial Muscle changes markedly with development, with a pronounced decrease in the proportion of Slow Muscle with ontogeny. We discuss our results in relation to the functional roles of each Muscle in larval and adult life and compare findings among a variety of vertebrates.
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The development of Muscle fiber type identity in zebrafish cranial Muscles
Anatomy and Embryology, 2005Co-Authors: L. Patricia Hernandez, Sara E. Patterson, Stephen H. DevotoAbstract:Cranial skeletal Muscles underlie breathing, eating, and eye movements. In most animals, at least two types of Muscle fibers underlie these critical functions: fast and Slow Muscle fibers. We describe here the anatomical distribution of Slow and fast twitch Muscle in the zebrafish (Danio rerio) head in the adult and at an early larval stage just after feeding has commenced. We found that all but one of the cranial Muscles examined contain both Slow and fast Muscle fibers, but the relative proportion of Slow Muscle in each varies considerably. As in the trunk, Slow Muscle fibers are found only in an anatomically restricted zone of each Muscle, usually on the periphery. The relative proportion of Slow and fast Muscle in each cranial Muscle changes markedly with development, with a pronounced decrease in the proportion of Slow Muscle with ontogeny. We discuss our results in relation to the functional roles of each Muscle in larval and adult life and compare findings among a variety of vertebrates.
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Hedgehog signaling is required for commitment but not initial induction of Slow Muscle precursors
Developmental biology, 2004Co-Authors: Estelle Hirsinger, Stephen H. Devoto, Frank Stellabotte, Monte WesterfieldAbstract:In zebrafish, skeletal Muscle precursors can adopt at least three distinct fates: fast, non-pioneer Slow, or pioneer Slow Muscle fibers. Slow Muscle fibers develop from adaxial cells and depend on Hedgehog signaling. We analyzed when precursors become committed to their fates and the step(s) along their differentiation pathway affected by Hedgehog. Unexpectedly, we find that embryos deficient in Hedgehog signaling still contain postmitotic adaxial cells that differentiate into fast Muscle fibers instead of Slow. We show that by the onset of gastrulation, Slow and fast Muscle precursors are already spatially segregated but uncommitted to their fates until much later, in the segmental plate when Slow precursors become independent of Hedgehog. In contrast, pioneer and non-pioneer Slow Muscle precursors share a common lineage from the onset of gastrulation. Our results demonstrate that Slow Muscle precursors form independently of Hedgehog signaling and further provide direct evidence for a multipotent Muscle precursor population whose commitment to the Slow fate depends on Hedgehog at a late stage of development when postmitotic adaxial cells differentiate into Slow Muscle fibers.
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Distinct mechanisms regulate Slow-Muscle development
Current biology : CB, 2001Co-Authors: Michael J.f. Barresi, Joel A. D'angelo, L. Patricia Hernandez, Stephen H. DevotoAbstract:Vertebrate Muscle development begins with the patterning of the paraxial mesoderm by inductive signals from midline tissues [1, 2]. Subsequent myotome growth occurs by the addition of new Muscle fibers. We show that in zebrafish new Slow-Muscle fibers are first added at the end of the segmentation period in growth zones near the dorsal and ventral extremes of the myotome, and this Muscle growth continues into larval life. In marine teleosts, this mechanism of growth has been termed stratified hyperplasia [3]. We have tested whether these added fibers require an embryonic architecture of Muscle fibers to support their development and whether their fate is regulated by the same mechanisms that regulate embryonic Muscle fates. Although Hedgehog signaling is required for the specification of adaxial-derived Slow-Muscle fibers in the embryo [4, 5], we show that in the absence of Hh signaling, stratified hyperplastic growth of Slow Muscle occurs at the correct time and place, despite the complete absence of embryonic Slow-Muscle fibers to serve as a scaffold for addition of these new Slow-Muscle fibers. We conclude that Slow-Muscle-stratified hyperplasia begins after the segmentation period during embryonic development and continues during the larval period. Furthermore, the mechanisms specifying the identity of these new Slow-Muscle fibers are different from those specifying the identity of adaxial-derived embryonic Slow-Muscle fibers. We propose that the independence of early, embryonic patterning mechanisms from later patterning mechanisms may be necessary for growth.
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The zebrafish Slow-Muscle-omitted gene product is required for Hedgehog signal transduction and the development of Slow Muscle identity.
Development (Cambridge England), 2000Co-Authors: Michael J.f. Barresi, Heather L. Stickney, Stephen H. DevotoAbstract:Hedgehog proteins mediate many of the inductive interactions that determine cell fate during embryonic development. Hedgehog signaling has been shown to regulate Slow Muscle fiber type development. We report here that mutations in the zebrafish Slow-Muscle-omitted (smu) gene disrupt many developmental processes involving Hedgehog signaling. smu(-/-) embryos have a 99% reduction in the number of Slow Muscle fibers and a complete loss of Engrailed-expressing Muscle pioneers. In addition, mutant embryos have partial cyclopia, and defects in jaw cartilage, circulation and fin growth. The smu(-/-) phenotype is phenocopied by treatment of wild-type embryos with forskolin, which inhibits the response of cells to Hedgehog signaling by indirect activation of cAMP-dependent protein kinase (PKA). Overexpression of Sonic hedgehog (Shh) or dominant negative PKA (dnPKA) in wild-type embryos causes all somitic cells to develop into Slow Muscle fibers. Overexpression of Shh does not rescue Slow Muscle fiber development in smu(-/-) embryos, whereas overexpression of dnPKA does. Cell transplantation experiments confirm that smu function is required cell-autonomously within the Muscle precursors: wild-type Muscle cells rescue Slow Muscle fiber development in smu(-/-) embryos, whereas mutant Muscle cells cannot develop into Slow Muscle fibers in wild-type embryos. Slow Muscle fiber development in smu mutant embryos is also rescued by expression of rat Smoothened. Therefore, Hedgehog signaling through Slow-Muscle-omitted is necessary for Slow Muscle fiber type development. We propose that smu encodes a vital component in the Hedgehog response pathway.
K. W. Ranatunga - One of the best experts on this subject based on the ideXlab platform.
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The effects of ramp stretches on active contractions in intact mammalian fast and Slow Muscle fibres
Journal of Muscle Research & Cell Motility, 2001Co-Authors: G. Mutungi, K. W. RanatungaAbstract:The effects of a ramp stretch (amplitude < 6% Muscle fibre length ( L _0), speed < 13 L _0 s^−1) on twitch tension and twitch tension re-development were examined in intact mammalian (rat) fast and Slow Muscle fibre bundles. The experiments were done in vitro at 20°C and at an initial sarcomere length of 2.68 μm. In both fibre types, a stretch applied during the rising phase of the twitch response (including the time of stimulation) increased the re-developed twitch tension (15–35%). A stretch applied before the stimulus had little or no effect on the twitch myogram in fast Muscle fibres, but it increased the twitch tension (∼5%) in Slow Muscle fibres. A similar stretch had little or no effect on tetanic tension in either Muscle fibre type. In general, the results indicate that the contractile-activation mechanism may be stretch sensitive and this is particularly pronounced in Slow Muscle fibres. Recorded at a high sampling rate and examined at an appropriate time scale, the transitory tension response to a stretch rose in at least two phases; an initial rapid tension rise to a break (break point tension, P _1 ^a) followed by a Slower tension rise (apparent P _2 ^a) to a peak reached at the end of the stretch. Plotted against stretch velocity, P _1 ^a tension increased in direct proportion to stretch velocity (viscous-like) whereas, P _2 ^a tension (calculated as peak tension minus P _1 ^a tension) increased with stretch velocity to a plateau (visco-elastic). Examined at the peak of a twitch, P _1 ^a tension had a slope (viscosity coefficient) of 1.8 kNm^−2 per L _0 s^−1 in fast fibres and 4.7 kNm^−2 per L _0 s^−1 in Slow Muscle fibres. In the same preparations, P _2 ^a tension had a relaxation time of 8 ms in the fast Muscle fibres and 25 ms in the Slow Muscle fibres. The amplitudes of both tension components scaled with the instantaneous twitch tension in qualitatively the same way as the instantaneous fibre stiffness. These fast/Slow fibre type differences probably reflect differences in their cross-bridge kinetics.
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Sarcomere length changes during end-held (isometric) contractions in intact mammalian (rat) fast and Slow Muscle fibres
Journal of Muscle Research & Cell Motility, 2000Co-Authors: G. Mutungi, K. W. RanatungaAbstract:The sarcomere length change, within a 2 mm region, during end-held isometric contractions in intact rat fast and Slow Muscle fibre bundles was investigated at 20°C and an initial sarcomere length of 2.68 μm using He–Ne laser diffraction. In some experiments, the fibre segment displacement was monitored with markers (pieces of human hair) placed at regular intervals on the surface of the Muscle fibre bundles. The sarcomere length changes, monitored near the proximal end of the bundle (transducer end), during tetanic contractions were similar to those previously reported in frog Muscle fibres. Thus, throughout the tension plateau, sarcomere length remained constant (and shortened) but showed evidence of non-uniform sarcomere behaviour (further shortening) during the rapid tension relaxation phase. Such non-uniform behaviour was not seen during twitch contractions. During a twitch contraction, sarcomeres at the proximal end shortened rapidly at first and continued to shorten – or remained shortened – until the tension had relaxed to between 20–23% of its peak value before lengthening back to the original length. The maximum twitch sarcomere shortening (mean ± SEM) was 5.9 ± 0.2% ( n = 16) in fast and 5.4 ± 0.3% ( n = 14) in Slow fibre bundles at 20°C; sarcomere shortening near body temperature (∼35°C) was greater, 8.8 ± 0.2% ( n = 7) in fast and 8.1 ± 0.2% ( n = 5) in Slow fibre bundles. Increasing the initial sarcomere length of a preparation decreased the extent of sarcomere shortening and reducing the amount of sarcomere shortening, by sarcomere length clamping, markedly increased the peak twitch tension without significantly altering the twitch time course. When examined at different positions along Muscle fibres, a sarcomere shortening was observed along much of the fibre length in most preparations. However, in about a third of the preparations some sarcomere lengthening was recorded in the distal end, but its amplitude was too small to accommodate the fibre shortening elsewhere. Complementary data were obtained using the surface marker technique. The displacement was largest and in opposite – but fibre shortening – direction in the markers placed ∼0.5–1.0 mm away from the two tendon attachments; the markers placed at or near the centre of the fibre bundle showed the least amount of displacement. The findings suggest that the compliant region, where lengthening occurs, is at fibre ends, i.e. near myotendinous junction.
Shugo Watabe - One of the best experts on this subject based on the ideXlab platform.
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promoter analysis of the fish gene of Slow cardiac type myosin heavy chain implicated in specification of Muscle fiber types
Fish Physiology and Biochemistry, 2018Co-Authors: Shigeharu Kinoshita, Shuichi Asakawa, Saltuk Buğrahan Ceyhun, Bhuiyan Sharmin Siddique, Dadasaheb B. Akolkar, Shugo WatabeAbstract:Vertebrate skeletal Muscles consist of heterogeneous tissues containing various types of Muscle fibers, where specification of the fiber type is crucial for Muscle development. Fish are an attractive experimental model to study the mechanisms of such fiber type specification because of the separated localization of Slow and fast Muscles in the trunk myotome. We examined regulation of expression of the torafugu gene of Slow/cardiac-type myosin heavy chain, MYH M5 , and isolated an operational promoter in order to force its tissue-specific expression across different fish species via the transgenic approach in zebrafish and medaka. This promoter activity was observed in adaxial cell-derived superficial Slow Muscle fibers under the control of a hedgehog signal. We also uncovered coordinated expression of MYH M5 and Sox6b, which is an important transcriptional repressor for specification of Muscle fiber types and participates in hedgehog signaling. Sequence comparison in the 5′-flanking region identified three conserved regions, CSR1–CSR3, between torafugu MYH M5 and its zebrafish ortholog. Analysis of deletion mutants showed that CSR1 significantly stimulates gene expression in Slow Muscle fibers. In contrast, deletion of CSR3 resulted in ectopic expression of a reporter gene in fast Muscle fibers. CSR3 was found to contain a putative Sox family protein-binding site. These results indicate that the dual mechanism causing inhibition in fast Muscle fibers and activation in Slow Muscle fibers is essential for Slow Muscle fiber-specific gene expression in fish.
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Promoter analysis of the fish gene of Slow/cardiac-type myosin heavy chain implicated in specification of Muscle fiber types.
Fish Physiology and Biochemistry, 2018Co-Authors: Shigeharu Kinoshita, Shuichi Asakawa, Saltuk Buğrahan Ceyhun, Asaduzzamann, Bhuiyan Sharmin Siddique, Dadasaheb B. Akolkar, Shugo WatabeAbstract:Vertebrate skeletal Muscles consist of heterogeneous tissues containing various types of Muscle fibers, where specification of the fiber type is crucial for Muscle development. Fish are an attractive experimental model to study the mechanisms of such fiber type specification because of the separated localization of Slow and fast Muscles in the trunk myotome. We examined regulation of expression of the torafugu gene of Slow/cardiac-type myosin heavy chain, MYH M5 , and isolated an operational promoter in order to force its tissue-specific expression across different fish species via the transgenic approach in zebrafish and medaka. This promoter activity was observed in adaxial cell-derived superficial Slow Muscle fibers under the control of a hedgehog signal. We also uncovered coordinated expression of MYH M5 and Sox6b, which is an important transcriptional repressor for specification of Muscle fiber types and participates in hedgehog signaling. Sequence comparison in the 5′-flanking region identified three conserved regions, CSR1–CSR3, between torafugu MYH M5 and its zebrafish ortholog. Analysis of deletion mutants showed that CSR1 significantly stimulates gene expression in Slow Muscle fibers. In contrast, deletion of CSR3 resulted in ectopic expression of a reporter gene in fast Muscle fibers. CSR3 was found to contain a putative Sox family protein-binding site. These results indicate that the dual mechanism causing inhibition in fast Muscle fibers and activation in Slow Muscle fibers is essential for Slow Muscle fiber-specific gene expression in fish.
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Stimulatory and inhibitory mechanisms of Slow Muscle-specific myosin heavy chain gene expression in fish: Transient and transgenic analysis of torafugu MYHM86-2 promoter in zebrafish embryos
Experimental Cell Research, 2012Co-Authors: Asaduzzaman, Shigeharu Kinoshita, Sharmin Siddique Bhuiyan, Shuichi Asakawa, Shugo WatabeAbstract:Abstract The myosin heavy chain gene, MYH M86-2 , exhibited restricted expression in Slow Muscle fibers of torafugu embryos and larvae, suggesting its functional roles for embryonic and larval Muscle development. However, the transcriptional mechanisms involved in its expression are still ambiguous. The present study is the first extensive analysis of Slow Muscle-specific MYH M86-2 promoter in fish for identifying the cis- elements that are crucial for its expression. Combining both transient transfection and transgenic approaches, we demonstrated that the 2614 bp 5′-flanking sequences of MYH M86-2 contain a sufficient promoter activity to drive gene expression specific to superficial Slow Muscle fibers. By cyclopamine treatment, we also demonstrated that the differentiation of such superficial Slow Muscle fibers depends on hedgehog signaling activity. The deletion analyses defined an upstream fragment necessary for repressing ectopic MYH M86-2 expression in the fast Muscle fibers. The transcriptional mechanism that prevents MYH M86-2 expression in the fast Muscle fibers is mediated through Sox6 binding elements. We also demonstrated that Sox6 may function as a transcriptional repressor of MYH M86-2 expression. We further discovered that nuclear factor of activated T cells (NFAT) binding elements plays a key role and myocyte enhancer factor-2 (MEF2) binding elements participate in the transcriptional regulation of MYH M86-2 expression.
Tamio Hirabayashi - One of the best experts on this subject based on the ideXlab platform.
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Natural Occurrence of Fast- and Fast/Slow-Muscle Chimeric Fibers in the Expression of Troponin T Isoforms
Experimental cell research, 1997Co-Authors: Kazuto Nakada, Jun-ichi Miyazaki, Rie Saba, Tamio HirabayashiAbstract:Rhomboideus, one of the back Muscle tissues, and its single fibers were studied in chickens by immunostaining with antisera against fast- and Slow-Muscle-type troponin T isoforms. Nonuniform distribution of Slow-Muscle-type isoforms was for the first time detected in single fibers isolated from the Muscle, although fast-Muscle-type troponin T isoforms were distributed over the whole length of the fiber. Based on these observations, we conclude that fast- and fast/Slow-Muscle chimeric fibers exist in normal skeletal Muscle tissue and that the existence of chimeric fibers is direct evidence showing that myonuclei subjected to different determination in troponin T isoform expression can together form a single Muscle fiber.
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Cloning of Chicken Slow Muscle Troponin T and Its Sequence Comparison with That of Human
Biochemical and biophysical research communications, 1996Co-Authors: Izuru Yonemura, Tsuyoshi Watanabe, Masashi Kirinoki, Jun-ichi Miyazaki, Tamio HirabayashiAbstract:A full-length cDNA coding for chicken Slow Muscle troponin T (TnT) was for the first time isolated from a cDNA library of 10-day-old embryos, using an RT-PCR product of chicken Slow Muscle TnT. It showed about 60% homology for chicken fast and Slow Muscle TnTs and 75.2% for human Slow Muscle TnT. The 16 amino acid sequence found in the carboxyl terminus of human Slow Muscle TnT was absent in the chicken Slow Muscle TnT. The 5E-5A-7E sequence found in the amino terminal region of chicken Slow Muscle TnT was partly similar to the counterpart of human Slow Muscle TnT, but not to those of chicken fast and cardiac Muscle TnTs. With this report of chicken Slow Muscle TnT, cDNA information on chicken TnTs of all three striated Muscles was completed following those of human TnTs.
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Coexistence of Fast-Muscle-Type and Slow-Muscle-Type Troponin T Isoforms in Single Chimeric Muscle Fibers Induced by Muscle Transplantation
Experimental cell research, 1994Co-Authors: Y. Yao, Jun-ichi Miyazaki, Tamio HirabayashiAbstract:Regenerated Muscle fibers which appeared after transplantation of chicken Slow Muscle (anterior latissimus dorsi) into breast fast Muscle (pectoralis major) of the same animal were studied by two-dimensional SDS-polyacrylamide gel electrophoresis, immunoblotting, and immunostaining with antisera against fast-Muscle-type troponin T and Slow-Muscle-type troponin T. In the transplanted Muscle, degeneration of Muscle fibers was followed by regeneration of Slow Muscle, which was revealed by detecting Slow-Muscle-type troponin T with the antiserum. Furthermore, coexistence of fast-Muscle-type and Slow-Muscle-type troponin T isoforms in single chimeric Muscle fibers composed of partly fast and partly Slow fibers was observed in the regenerated Muscle. We suggested that the chimeric fibers were originated from the fusion of fast and Slow myoblasts during regeneration after Muscle transplantation and that two nuclei differently determined in troponin T expression were working independently in a single cell.
Simon M Hughes - One of the best experts on this subject based on the ideXlab platform.
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hedgehog regulation of superficial Slow Muscle fibres in xenopus and the evolution of tetrapod trunk myogenesis
Development, 2004Co-Authors: A Grimaldi, Gianluca Tettamanti, Benjamin L Martin, William Gaffield, Mary Elizabeth Pownall, Simon M HughesAbstract:In tetrapod phylogeny, the dramatic modifications of the trunk have received less attention than the more obvious evolution of limbs. In somites, several waves of Muscle precursors are induced by signals from nearby tissues. In both amniotes and fish, the earliest myogenesis requires secreted signals from the ventral midline carried by Hedgehog (Hh) proteins. To determine if this similarity represents evolutionary homology, we have examined myogenesis in Xenopus laevis, the major species from which insight into vertebrate mesoderm patterning has been derived. Xenopus embryos form two distinct kinds of Muscle cells analogous to the superficial Slow and medial fast Muscle fibres of zebrafish. As in zebrafish, Hh signalling is required for XMyf5 expression and generation of a first wave of early superficial Slow Muscle fibres in tail somites. Thus, Hh-dependent adaxial myogenesis is the likely ancestral condition of teleosts, amphibia and amniotes. Our evidence suggests that midline-derived cells migrate to the lateral somite surface and generate superficial Slow Muscle. This cell re-orientation contributes to the apparent rotation of Xenopus somites. Xenopus myogenesis in the trunk differs from that in the tail. In the trunk, the first wave of superficial Slow fibres is missing, suggesting that significant adaptation of the ancestral myogenic programme occurred during tetrapod trunk evolution. Although notochord is required for early medial XMyf5 expression, Hh signalling fails to drive these cells to Slow myogenesis. Later, both trunk and tail somites develop a second wave of Hh-independent Slow fibres. These fibres probably derive from an outer cell layer expressing the myogenic determination genes XMyf5, XMyoD and Pax3 in a pattern reminiscent of amniote dermomyotome. Thus, Xenopus somites have characteristics in common with both fish and amniotes that shed light on the evolution of somite differentiation. We propose a model for the evolutionary adaptation of myogenesis in the transition from fish to tetrapod trunk.
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Muscle differentiation: a gene for Slow Muscle?
Current biology : CB, 2004Co-Authors: Simon M HughesAbstract:Skeletal Muscle comes in two fundamental flavours, Slow and fast, which determine physiological performance. Zebrafish screens have provided a handle on the molecular mechanism driving Slow Muscle formation. The transcriptional repressor Blimp1 has now been shown to be required in embryonic Slow Muscle precursor cells.
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Notochord induction of zebrafish Slow Muscle mediated by Sonic hedgehog
Genes & development, 1997Co-Authors: Chris S. Blagden, Peter D. Currie, Philip W. Ingham, Simon M HughesAbstract:The patterning of vertebrate somitic Muscle is regulated by signals from neighboring tissues. We examined the generation of Slow and fast Muscle in zebrafish embryos and show that Sonic hedgehog (Shh) secreted from the notochord can induce Slow Muscle from medial cells of the somite. Slow Muscle derives from medial adaxial myoblasts that differentiate early, whereas fast Muscle arises later from a separate myoblast pool. Mutant fish lacking shh expression fail to form Slow Muscle but do form fast Muscle. Ectopic expression of shh, either in wild-type or mutant embryos, leads to ectopic Slow Muscle at the expense of fast. We suggest that Shh acts to induce myoblasts committed to Slow Muscle differentiation from uncommitted presomitic mesoderm.
