Initial steps of myogenesis in somites are independent of influence from axial structures

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3073-3082 ◽  
Author(s):  
E. Bober ◽  
B. Brand-Saberi ◽  
C. Ebensperger ◽  
J. Wilting ◽  
R. Balling ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Neural Tube ◽  
Cell Lineage ◽  
Subsequent Development ◽  
Paraxial Mesoderm ◽  
Surgical Removal ◽  
Axial Muscles ◽  
Muscle Formation ◽  
Vertebrate Embryos ◽  
Myotomal Muscle

Formation of paraxial muscles in vertebrate embryos depends upon interactions between early somites and the neural tube and notochord. Removal of both axial structures results in a complete loss of epaxial myotomal muscle, whereas hypaxial and limb muscles develop normally. We report that chicken embryos, after surgical removal of the neural tube at the level of the unsegmented paraxial mesoderm, start to develop myotomal cells that express transcripts for the muscle-specific regulators MyoD and myogenin. These cells also make desmin, indicating that the initial steps of axial skeletal muscle formation can occur in the absence of the neural tube. However, a few days following the extirpation, the expression of MyoD and myogenin transcripts gradually disappears, and becomes almost undetectable after 4 days. From these observations we conclude that the neural tube is not required for the generation of the skeletal muscle cell lineage, but may support the survival or maitenance of further differentiation of the myotomal cell compartment. Notochord transplanted medially or laterally to the unsegmented paraxial mesoderm leads to a ventralization of axial structures but does not entirely prevent the early appearance of myoblasts expressing MyoD transcripts. However, the additional notochord inhibits subsequent development and maturation of myotomes. Taken together, our data suggest that neural tube promotes, and notochord inhibits, the process of myogenesis in axial muscles at a developmental step following the initial expression of myogenic bHLH regulators.

Differential activation of Myf5 and MyoD by different Wnts in explants of mouse paraxial mesoderm and the later activation of myogenesis in the absence of Myf5

Development ◽  
1998 ◽  
Vol 125 (21) ◽  
pp. 4155-4162 ◽  
Author(s):  
S. Tajbakhsh ◽  
U. Borello ◽  
E. Vivarelli ◽  
R. Kelly ◽  
J. Papkoff ◽  
...  
Keyword(s):  
Neural Tube ◽  
Muscle Development ◽  
Early Embryo ◽  
Paraxial Mesoderm ◽  
Dorsal Neural Tube ◽  
Muscle Formation ◽  
Correct Pattern ◽  
Dorsal Ectoderm ◽  
Dependent Pathway

Activation of myogenesis in newly formed somites is dependent upon signals derived from neighboring tissues, namely axial structures (neural tube and notochord) and dorsal ectoderm. In explants of paraxial mesoderm from mouse embryos, axial structures preferentially activate myogenesis through a Myf5-dependent pathway and dorsal ectoderm preferentially through a MyoD-dependent pathway. Here we report that cells expressing Wnt1 will preferentially activate Myf5 while cells expressing Wnt7a will preferentially activate MyoD. Wnt1 is expressed in the dorsal neural tube and Wnt7a in dorsal ectoderm in the early embryo, therefore both can potentially act in vivo to activate Myf5 and MyoD, respectively. Wnt4, Wnt5a and Wnt6 exert an intermediate effect activating both Myf5 and MyoD equivalently in paraxial mesoderm. Sonic Hedgehog synergises with both Wnt1 and Wnt7a in explants from E8.5 paraxial mesoderm but not in explants from E9.5 embryos. Signaling through different myogenic pathways may explain the rescue of muscle formation in Myf5 null embryos, which do not form an early myotome but later develop both epaxial and hypaxial musculature. Explants of unsegmented paraxial mesoderm contain myogenic precursors capable of expressing MyoD in response to signaling from a neural tube isolated from E10.5 embryos, the developmental stage when MyoD is present throughout the embryo. Myogenic cells cannot activate MyoD in response to signaling from a less mature neural tube. Together these data suggest that different Wnt molecules can activate myogenesis through different pathways such that commitment of myogenic precursors is precisely regulated in space and time to achieve the correct pattern of skeletal muscle development.

Pax3 functions in cell survival and in pax7 regulation

Development ◽  
1999 ◽  
Vol 126 (8) ◽  
pp. 1665-1674 ◽  
Author(s):  
A.G. Borycki ◽  
J. Li ◽  
F. Jin ◽  
C.P. Emerson ◽  
J.A. Epstein
Keyword(s):  
Cell Survival ◽  
Neural Tube ◽  
Muscle Development ◽  
Paraxial Mesoderm ◽  
Wild Type ◽  
Presomitic Mesoderm ◽  
Surface Ectoderm ◽  
Dorsal Neural Tube ◽  
Vertebrate Embryos ◽  
Somitic Mesoderm

In developing vertebrate embryos, Pax3 is expressed in the neural tube and in the paraxial mesoderm that gives rise to skeletal muscles. Pax3 mutants develop muscular and neural tube defects; furthermore, Pax3 is essential for the proper activation of the myogenic determination factor gene, MyoD, during early muscle development and PAX3 chromosomal translocations result in muscle tumors, providing evidence that Pax3 has diverse functions in myogenesis. To investigate the specific functions of Pax3 in development, we have examined cell survival and gene expression in presomitic mesoderm, somites and neural tube of developing wild-type and Pax3 mutant (Splotch) mouse embryos. Disruption of Pax3 expression by antisense oligonucleotides significantly impairs MyoD activation by signals from neural tube/notochord and surface ectoderm in cultured presomitic mesoderm (PSM), and is accompanied by a marked increase in programmed cell death. In Pax3 mutant (Splotch) embryos, MyoD is activated normally in the hypaxial somite, but MyoD-expressing cells are disorganized and apoptosis is prevalent in newly formed somites, but not in the neural tube or mature somites. In neural tube and somite regions where cell survival is maintained, the closely related Pax7 gene is upregulated, and its expression becomes expanded into the dorsal neural tube and somites, where Pax3 would normally be expressed. These results establish that Pax3 has complementary functions in MyoD activation and inhibition of apoptosis in the somitic mesoderm and in repression of Pax7 during neural tube and somite development.

scholarly journals A cell lineage analysis of segmentation in the chick embryo

Development ◽  
1988 ◽  
Vol 104 (Supplement) ◽  
pp. 231-244 ◽  
Author(s):  
Claudio D. Stern ◽  
Scott E. Fraser ◽  
Roger J. Keynes ◽  
Dennis R. N. Primmett
Keyword(s):  
Cell Division ◽  
Chick Embryo ◽  
Neural Tube ◽  
Single Cells ◽  
Cell Lineage ◽  
Subsequent Development ◽  
Ventral Horn ◽  
Cell Division Cycle ◽  
Lateral Plate ◽  
Somite Formation

We have studied the lineage history of the progenitors of the somite mesoderm and of the neural tube in the chick embryo by injecting single cells with the fluorescent tracer, rhodamine-lysine-dextran. We find that, although single cells within the segmental plate give rise to discrete clones in the somites to which they contribute, neither the somites nor their component parts (sclerotome, dermatome, myotome or their rostral and caudal halves) are `compartments' in the sense defined in insects. Cells in the rostral two thirds or so of the segmental plate contribute only to somite tissue and divide about every 10 h, while those in the caudal portions of this structure contribute both to the somites and to intermediate and lateral plate mesoderm derivatives. In the neural tube, the descendants of individual prospective ventral horn cells remain together within the horn, with a cycle time of 10 h. We have also investigated the role of the cell division cycle in the formation and subsequent development of somites. A single treatment of 2-day chick embryos with heat shock or a variety of drugs that affect the cell cycle all produce repeated anomalies in the pattern of somites and vertebrae that develop subsequent to the treatment. The interval between anomalies is 6-7 somites (or a multiple of this distance), which corresponds to 10 h. This interval is identical to that measured for the cell division cycle. Given that cell division synchrony is seen in the presomitic mesoderm, we suggest that the cell division cycle plays a role in somite formation. Finally, we consider the mechanisms responsible for regionalization of derivatives of the somite, and conclude that it is likely that both cell interactions and cell lineage history are important in the determination of cell fates.

scholarly journals HIRA stabilizes skeletal muscle lineage identity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joana Esteves de Lima ◽  
Reem Bou Akar ◽  
Léo Machado ◽  
Yuefeng Li ◽  
Bernadette Drayton-Libotte ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Lineage ◽  
Promoter Regions ◽  
Cell Fates ◽  
Regulatory Regions ◽  
Muscle Stem Cells ◽  
Adult Mice ◽  
H3k4me3 Mark ◽  
Muscle Genes ◽  
Muscle Gene

AbstractThe epigenetic mechanisms coordinating the maintenance of adult cellular lineages and the inhibition of alternative cell fates remain poorly understood. Here we show that targeted ablation of the histone chaperone HIRA in myogenic cells leads to extensive transcriptional modifications, consistent with a role in maintaining skeletal muscle cellular identity. We demonstrate that conditional ablation of HIRA in muscle stem cells of adult mice compromises their capacity to regenerate and self-renew, leading to tissue repair failure. Chromatin analysis of Hira-deficient cells show a significant reduction of histone variant H3.3 deposition and H3K27ac modification at regulatory regions of muscle genes. Additionally, we find that genes from alternative lineages are ectopically expressed in Hira-mutant cells via MLL1/MLL2-mediated increase of H3K4me3 mark at silent promoter regions. Therefore, we conclude that HIRA sustains the chromatin landscape governing muscle cell lineage identity via incorporation of H3.3 at muscle gene regulatory regions, while preventing the expression of alternative lineage genes.

Myogenesis in paraxial mesoderm: preferential induction by dorsal neural tube and by cells expressing Wnt-1

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3675-3686 ◽  
Author(s):  
H.M. Stern ◽  
A.M. Brown ◽  
S.D. Hauschka
Keyword(s):  
Neural Tube ◽  
Muscle Development ◽  
Paraxial Mesoderm ◽  
Myogenic Response ◽  
Dorsal Neural Tube ◽  
Ventral Neural Tube ◽  
Myogenic Induction ◽  
Inductive Activity

Previous studies have demonstrated that the neural tube/notochord complex is required for skeletal muscle development within somites. In order to explore the localization of myogenic inducing signals within the neural tube, dorsal or ventral neural tube halves were cultured in contact with single somites or pieces of segmental plate mesoderm. Somites and segmental plates cultured with the dorsal half of the neural tube exhibited 70% and 85% myogenic response rates, as determined by immunostaining for myosin heavy chain. This response was slightly lower than the 100% response to whole neural tube/notochord, but was much greater than the 30% and 10% myogenic response to ventral neural tube with and without notochord. These results demonstrate that the dorsal neural tube emits a potent myogenic inducing signal which accounts for most of the inductive activity of whole neural tube/notochord. However, a role for ventral neural tube/notochord in somite myogenic induction was clearly evident from the larger number of myogenic cells induced when both dorsal neural tube and ventral neural tube/notochord were present. To address the role of a specific dorsal neural tube factor in somite myogenic induction, we tested the ability of Wnt-1-expressing fibroblasts to promote paraxial mesoderm myogenesis in vitro. We found that cells expressing Wnt-1 induced a small number of somite and segmental plate cells to undergo myogenesis. This finding is consistent with the localized dorsal neural tube inductive activity described above, but since the ventral neural tube/notochord also possesses myogenic inductive capacity yet does not express Wnt-1, additional inductive factors are likely involved.

Cell-autonomous shift from axial to paraxial mesodermal development in zebrafish floating head mutants

Development ◽  
1995 ◽  
Vol 121 (12) ◽  
pp. 4257-4264 ◽  
Author(s):  
M.E. Halpern ◽  
C. Thisse ◽  
R.K. Ho ◽  
B. Thisse ◽  
B. Riggleman ◽  
...  
Keyword(s):  
Neural Tube ◽  
Single Cells ◽  
Floor Plate ◽  
Paraxial Mesoderm ◽  
Wild Type ◽  
Genetic Mosaics ◽  
Essential Step ◽  
Ventral Neural Tube ◽  
Mesodermal Development

Zebrafish floating head mutant embryos lack notochord and develop somitic muscle in its place. This may result from incorrect specification of the notochord domain at gastrulation, or from respecification of notochord progenitors to form muscle. In genetic mosaics, floating head acts cell autonomously. Transplanted wild-type cells differentiate into notochord in mutant hosts; however, cells from floating head mutant donors produce muscle rather than notochord in wild-type hosts. Consistent with respecification, markers of axial mesoderm are initially expressed in floating head mutant gastrulas, but expression does not persist. Axial cells also inappropriately express markers of paraxial mesoderm. Thus, single cells in the mutant midline transiently co-express genes that are normally specific to either axial or paraxial mesoderm. Since floating head mutants produce some floor plate in the ventral neural tube, midline mesoderm may also retain early signaling capabilities. Our results suggest that wild-type floating head provides an essential step in maintaining, rather than initiating, development of notochord-forming axial mesoderm.

scholarly journals Mechanism and Functions of Identified miRNAs in Poultry Skeletal Muscle Development – A Review

2019 ◽  
Vol 19 (4) ◽  
pp. 887-904
Author(s):  
Asiamah Amponsah Collins ◽  
Kun Zou ◽  
Zhang Li ◽  
Su Ying
Keyword(s):  
Skeletal Muscle ◽  
Candidate Genes ◽  
Skeletal Muscles ◽  
Muscle Development ◽  
Muscle Growth ◽  
Skeletal Muscle Development ◽  
Single Nucleotide ◽  
Complex Processes ◽  
Muscle Formation ◽  
Gene Regulatory

AbstractDevelopment of the skeletal muscle goes through several complex processes regulated by numerous genetic factors. Although much efforts have been made to understand the mechanisms involved in increased muscle yield, little work is done about the miRNAs and candidate genes that are involved in the skeletal muscle development in poultry. Comprehensive research of candidate genes and single nucleotide related to poultry muscle growth is yet to be experimentally unraveled. However, over a few periods, studies in miRNA have disclosed that they actively participate in muscle formation, differentiation, and determination in poultry. Specifically, miR-1, miR-133, and miR-206 influence tissue development, and they are highly expressed in the skeletal muscles. Candidate genes such as CEBPB, MUSTN1, MSTN, IGF1, FOXO3, mTOR, and NFKB1, have also been identified to express in the poultry skeletal muscles development. However, further researches, analysis, and comprehensive studies should be made on the various miRNAs and gene regulatory factors that influence the skeletal muscle development in poultry. The objective of this review is to summarize recent knowledge in miRNAs and their mode of action as well as transcription and candidate genes identified to regulate poultry skeletal muscle development.

Identification of tissues and patterning events required for distinct steps in early migration of zebrafish primordial germ cells

Development ◽  
1999 ◽  
Vol 126 (23) ◽  
pp. 5295-5307 ◽  
Author(s):  
G. Weidinger ◽  
U. Wolke ◽  
M. Koprunner ◽  
M. Klinger ◽  
E. Raz
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Paraxial Mesoderm ◽  
Molecular Characteristics ◽  
Dorsoventral Patterning ◽  
Wild Type ◽  
Migration Process ◽  
Early Migration ◽  
Somatic Tissues

In many organisms, the primordial germ cells have to migrate from the position where they are specified towards the developing gonad where they generate gametes. Extensive studies of the migration of primordial germ cells in Drosophila, mouse, chick and Xenopus have identified somatic tissues important for this process and demonstrated a role for specific molecules in directing the cells towards their target. In zebrafish, a unique situation is found in that the primordial germ cells, as marked by expression of vasa mRNA, are specified in random positions relative to the future embryonic axis. Hence, the migrating cells have to navigate towards their destination from various starting positions that differ among individual embryos. Here, we present a detailed description of the migration of the primordial germ cells during the first 24 hours of wild-type zebrafish embryonic development. We define six distinct steps of migration bringing the primordial germ cells from their random positions before gastrulation to form two cell clusters on either side of the midline by the end of the first day of development. To obtain information on the origin of the positional cues provided to the germ cells by somatic tissues during their migration, we analyzed the migration pattern in mutants, including spadetail, swirl, chordino, floating head, cloche, knypek and no isthmus. In mutants with defects in axial structures, paraxial mesoderm or dorsoventral patterning, we find that certain steps of the migration process are specifically affected. We show that the paraxial mesoderm is important for providing proper anteroposterior information to the migrating primordial germ cells and that these cells can respond to changes in the global dorsoventral coordinates. In certain mutants, we observe accumulation of ectopic cells in different regions of the embryo. These ectopic cells can retain both morphological and molecular characteristics of primordial germ cells, suggesting that, in zebrafish at the early stages tested, the vasa-expressing cells are committed to the germ cell lineage.

Hoxd10 induction and regionalization in the developing lumbosacral spinal cord

Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2255-2268 ◽  
Author(s):  
Cynthia Lance-Jones ◽  
Natalia Omelchenko ◽  
Anya Bailis ◽  
Stephen Lynch ◽  
Kamal Sharma
Keyword(s):  
Spinal Cord ◽  
Neural Tube ◽  
Neural Tube Closure ◽  
Paraxial Mesoderm ◽  
Lumbosacral Region ◽  
Environmental Signals ◽  
Lumbosacral Spinal Cord ◽  
Column Formation ◽  
Lim Proteins ◽  
High Level

We have used Hoxd10 expression as a primary marker of the lumbosacral region to examine the early programming of regional characteristics within the posterior spinal cord of the chick embryo. Hoxd10 is uniquely expressed at a high level in the lumbosacral cord, from the earliest stages of motor column formation through stages of motoneuron axon outgrowth. To define the time period when this gene pattern is determined, we assessed Hoxd10 expression after transposition of lumbosacral and thoracic segments at early neural tube stages. We present evidence that there is an early prepattern for Hoxd10 expression in the lumbosacral neural tube; a prepattern that is established at or before stages of neural tube closure. Cells within more posterior lumbosacral segments have a greater ability to develop high level Hoxd10 expression than the most anterior lumbosacral segments or thoracic segments. During subsequent neural tube stages, this prepattern is amplified and stabilized by environmental signals such that all lumbosacral segments acquire the ability to develop high levels of Hoxd10, independent of their axial environment. Results from experiments in which posterior neural segments and/or paraxial mesoderm segments were placed at different axial levels suggest that signals setting Hoxd10 expression form a decreasing posterior-to-anterior gradient. Our experiments do not, however, implicate adjacent paraxial mesoderm as the only source of graded signals. We suggest, instead, that signals from more posterior embryonic regions influence Hoxd10 expression after the early establishment of a regional prepattern. Concurrent analyses of patterns of LIM proteins and motor column organization after experimental surgeries suggest that the programming of these characteristics follows similar rules.

The control of rostrocaudal pattern in the developing spinal cord: specification of motor neuron subtype identity is initiated by signals from paraxial mesoderm

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 969-982 ◽  
Author(s):  
M. Ensini ◽  
T.N. Tsuchida ◽  
H.G. Belting ◽  
T.M. Jessell
Keyword(s):  
Spinal Cord ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Neural Tube ◽  
Motor Behavior ◽  
Neural Tube Closure ◽  
Paraxial Mesoderm ◽  
Homeodomain Protein ◽  
Mesodermal Cell ◽  
Developing Spinal Cord

The generation of distinct classes of motor neurons is an early step in the control of vertebrate motor behavior. To study the interactions that control the generation of motor neuron subclasses in the developing avian spinal cord we performed in vivo grafting studies in which either the neural tube or flanking mesoderm were displaced between thoracic and brachial levels. The positional identity of neural tube cells and motor neuron subtype identity was assessed by Hox and LIM homeodomain protein expression. Our results show that the rostrocaudal identity of neural cells is plastic at the time of neural tube closure and is sensitive to positionally restricted signals from the paraxial mesoderm. Such paraxial mesodermal signals appear to control the rostrocaudal identity of neural tube cells and the columnar subtype identity of motor neurons. These results suggest that the generation of motor neuron subtypes in the developing spinal cord involves the integration of distinct rostrocaudal and dorsoventral patterning signals that derive, respectively, from paraxial and axial mesodermal cell groups.

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