scholarly journals Mechanical strain can increase segment number in live chick embryos

2017 ◽  
Author(s):  
Ben K. A. Nelemans ◽  
Manuel Schmitz ◽  
Hannan Tahir ◽  
Roeland M. H. Merks ◽  
Theodoor H. Smit
Keyword(s):  
Mechanical Strain ◽  
Self Organization ◽  
Chick Embryos ◽  
Border Cells ◽  
Cellular Potts Model ◽  
Mechanical Environment ◽  
Physical Cues ◽  
Species Specific ◽  
Mechanical Stretching ◽  
Somitic Mesoderm

AbstractPhysical cues, experienced during early embryonic development, can influence species-specific vertebral numbers. Here we show that mechanical stretching of live chicken embryos can induce the formation of additional somites and thereby modify early segmental patterning. Stretching deforms the somites, and results in a cellular reorganization that forms stable daughter somites. Cells from the somite core thereby undergo mesenchymal-to-epithelial transitions (MET), thus meeting the geometrical demand for more border cells. Using a Cellular Potts Model, we suggest that this MET occurs through lateral induction by the existing epithelial cells. Our results indicate that self-organizing properties of the somitic mesoderm generate phenotypic plasticity that allows it to cope with variations in the mechanical environment. This plasticity may provide a novel mechanism for explaining how vertebral numbers in species may have increased during evolution. Additionally, by preventing the formation of transitional vertebrae, these self-organization qualities of somites may be selectively advantageous.

Density-dependent and species-specific effects on self-organization modulate the resistance of mussel bed ecosystems to hydrodynamic stress

2021 ◽  
Author(s):  
Gerardo I. Zardi ◽  
Katy Rebecca Nicastro ◽  
Christopher D. McQuaid ◽  
Monique de Jager ◽  
Johan van de Koppel ◽  
...  
Keyword(s):  
Self Organization ◽  
Mussel Bed ◽  
Hydrodynamic Stress ◽  
Density Dependent ◽  
Specific Effects ◽  
Species Specific

scholarly journals Porous Geometry Guided Micro-mechanical Environment Within Scaffolds for Cell Mechanobiology Study in Bone Tissue Engineering

2021 ◽  
Vol 9 ◽  
Author(s):  
Feihu Zhao ◽  
Yi Xiong ◽  
Keita Ito ◽  
Bert van Rietbergen ◽  
Sandra Hofmann
Keyword(s):  
Porous Scaffold ◽  
Mechanical Strain ◽  
Three Dimensional ◽  
Pore Geometry ◽  
Cell Physiology ◽  
Porous Scaffolds ◽  
Mechanical Environment ◽  
Functional Features ◽  
Future Work

Mechanobiology research is for understanding the role of mechanics in cell physiology and pathology. It will have implications for studying bone physiology and pathology and to guide the strategy for regenerating both the structural and functional features of bone. Mechanobiological studies in vitro apply a dynamic micro-mechanical environment to cells via bioreactors. Porous scaffolds are commonly used for housing the cells in a three-dimensional (3D) culturing environment. Such scaffolds usually have different pore geometries (e.g. with different pore shapes, pore dimensions and porosities). These pore geometries can affect the internal micro-mechanical environment that the cells experience when loaded in the bioreactor. Therefore, to adjust the applied micro-mechanical environment on cells, researchers can tune either the applied load and/or the design of the scaffold pore geometries. This review will provide information on how the micro-mechanical environment (e.g. fluid-induced wall shear stress and mechanical strain) is affected by various scaffold pore geometries within different bioreactors. It shall allow researchers to estimate/quantify the micro-mechanical environment according to the already known pore geometry information, or to find a suitable pore geometry according to the desirable micro-mechanical environment to be applied. Finally, as future work, artificial intelligent – assisted techniques, which can achieve an automatic design of solid porous scaffold geometry for tuning/optimising the micro-mechanical environment are suggested.

Rôle du mésoderme somitique dans le développement du plumage dorsal chez l'embryon de Poulet

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 343-366
Author(s):  
Par Annick Mauger
Keyword(s):  
Early Stage ◽  
Cervical Region ◽  
Lumbar Region ◽  
Chick Embryos ◽  
A Chain ◽  
Normal Differentiation ◽  
Time Of Operation ◽  
Somitic Mesoderm ◽  
Axial Organs

The role of somitic mesoderm in the development of dorsal plumage in chick embryos. II. Regionalisation. Transplantation and inversion experiments were performed on the somitic mesoderm of 2- to 2·5-day chick embryos in order to study the role of regional and axial determinations in the development of the dorsal plumage. The transposition of a piece of somitic mesoderm from the posterior cervical region (where the spinal pteryla is narrow) to the thoraco-lumbar region (where it is wide) leads to a local and unilateral narrowing of the spinal pteryla at the operation site. Conversely, the transposition of somitic mesoderm from the thoraco-lumbar region to the posterior cervical region results in a local and unilateral widening of the spinal pteryla. Consequently at the time of operation the segmented or not yet segmented somitic mesoderm is already determined to give rise to a definite transverse level of the spinal pteryla. The inversion of the cephalo-caudal polarity of a piece of somitic mesoderm without the ectodermal covering, or of a portion of the axial organs deprived of the overlying ectoderm has no effect on the orientation of feather filaments and feather rows. In contrast, the inversion of the cephalo-caudal polarity of a portion of the axial organs together with the overlying ectoderm results in the development of feathers growing in a cephalad direction and feather chevrons opening towards the head of the embryo. The inversion of the dorso-ventral polarity of a piece of somitic mesoderm does not prevent the normal differentiation of feathers in the operated region. The inversion of the medio-lateral polarity of a piece of unsegmented somitic mesoderm has little effect on the development of the spinal pteryla. On the contrary, the medio-lateral inversion of a chain of somites precludes the formation of the feathers at the level of operation. The somitic mesoderm, even when segmented, is endowed with extensive regulative capacity of its axes, except for the medio-lateral polarity, which is fixed irreversibly at the time of segmentation. The regional determination of the feather-forming somitic mesoderm is acquired at an early stage, at any rate before segmentation. However, at a given transverse level of the cephalo-caudal axis, the somitic cells remain totipotent as concerns their histo-genetic destiny (dermatome, myotome, or sclerotome) until after the onset of segmentation.

Formation of Wrinkle Patterns on Porous Elastomeric Membrane and Their Fabrication of Hierarchical Architectures

2008 ◽  
Vol 1129 ◽  
Author(s):  
Yue Cui ◽  
Shu Yang
Keyword(s):  
Cell Attachment ◽  
Mechanical Strain ◽  
Crystal Formation ◽  
Plasma Oxidation ◽  
Oxidation Condition ◽  
Uv Curable ◽  
Replica Molding ◽  
Hierarchical Architectures ◽  
Elastomeric Membrane ◽  
Mechanical Stretching

AbstractWe report the formation of wrinkle patterns on porous elastomeric membrane and their fabrication of hierarchical architectures through mechanical stretching and replica molding. The technique builds upon a buckling instability of a stiff layer supported by a porous elastomeric membrane which was induced by surface plasma oxidation of the pre-stretched porous elastomer followed by removal of the applied mechanical strain to form wrinkle patterns, and replica molding of the deformed features on the porous membrane into epoxy to form hierarchical architectures through casting the UV-curable epoxy prepolymer and UV curing. We find that due to the existence of micropores on the membrane, the formation of wrinkle patterns is different from that formed on a continuous elastomeric film, and by varying the applied mechanical stretching strain condition and plasma oxidation condition, the wrinkle patterns could be either confined by the micropores on the membrane to exhibit a wavelength equal to its pitch or form wrinkles with much large wavelength compared with that formed on a continuous elastomeric film. Therefore, the micropillar arrays fabricated by replica molding could stand on different types of wrinkle patterns to form different hierarchical architectures. The method we illustrate here offers a simple and cost-effective approach to fabricate various hierarchical structures, and provides possibilities for potential applications in various fields, such as microfluidics, micro- and nanofabrication of complex structures, crystal formation, cell attachment, superhydrophobicity and dry adhesion.

Effects of Mechanical Strain on Structural and Actin-Binding Proteins in Neuroblasts

2009 ◽  
Author(s):  
Szu-Yuan Chou ◽  
Chao-Min Cheng ◽  
Yi-Wen Lin ◽  
Chih-Cheng Chen ◽  
Philip R. LeDuc
Keyword(s):  
Sensory Neurons ◽  
Mechanical Stimulation ◽  
Binding Proteins ◽  
Mechanical Strain ◽  
Actin Binding ◽  
Potential Capacity ◽  
Static Mechanical ◽  
Animal Growth ◽  
Mechanical Stretching ◽  
Insight Into

Mechanical stimulation affects the functioning and outgrowth of neurons and has the potential capacity for regeneration. Mechanoreceptors in sensory neurons act as a conduit to respond to pain and touch while neurites experience mechanical stimulation during the process of animal growth. To understand mechanotransduction in neural outgrowth, we used a custom fabricated device to investigate the effects of static mechanical stretching while examining molecular connections such as advillin and actin. Our results have the potential of providing greater understanding of mechanotransduction in neuroblasts, as well as providing insight into mechanical approaches that might be used in increasing neural outgrowth.

Determination of somite cells: independence of cell differentiation and morphogenesis

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 15-28 ◽  
Author(s):  
H. Aoyama ◽  
K. Asamoto
Keyword(s):  
Cell Differentiation ◽  
Dorsal Root ◽  
Vertebral Column ◽  
The Other ◽  
Chick Embryos ◽  
Dorsoventral Axis ◽  
Motor Nerves ◽  
Rostrocaudal Axis ◽  
Somitic Mesoderm

Somites are mesodermal structures which appear transiently in vertebrates in the course of their development. Cells situated ventromedially in a somite differentiate into the sclerotome, which gives rise to cartilage, while the other part of the somite differentiates into dermomyotome which gives rise to muscle and dermis. The sclerotome is further divided into a rostral half, where neural crest cells settle and motor nerves grow, and a caudal half. To find out when these axes are determined and how they rule later development, especially the morphogenesis of cartilage derived from the somites, we transplanted the newly formed three caudal somites of 2.5-day-old quail embryos into chick embryos of about the same age, with reversal of some axes. The results were summarized as follows. (1) When transplantation reversed only the dorsoventral axis, one day after the operation the two caudal somites gave rise to normal dermomyotomes and sclerotomes, while the most rostral somite gave rise to a sclerotome abnormally situated just beneath ectoderm. These results suggest that the dorsoventral axis was not determined when the somites were formed, but began to be determined about three hours after their formation. (2) When the transplantation reversed only the rostrocaudal axis, two days after the operation the rudiments of dorsal root ganglia were formed at the caudal (originally rostral) halves of the transplanted sclerotomes. The rostrocaudal axis of the somites had therefore been determined when the somites were formed. (3) When the transplantation reversed both the dorsoventral and the rostrocaudal axes, two days after the operation, sclerotomes derived from the prospective dermomyotomal region of the somites were shown to keep their original rostrocaudal axis, judging from the position of the rudiments of ganglia. Combined with results 1 and 2, this suggested that the fate of the sclerotomal cells along the rostrocaudal axis was determined previously and independently of the determination of somite cell differentiation into dermomyotome and sclerotome. (4) In the 9.5-day-old chimeric embryos with rostrocaudally reversed somites, the morphology of vertebrae and ribs derived from the explanted somites were reversed along the rostrocaudal axis. The morphology of cartilage derived from the somites was shown to be determined intrinsically in the somites by the time these were formed from the segmental plate. The rostrocaudal pattern of the vertebral column is therefore controlled by factors intrinsic to the somitic mesoderm, and not by interactions between this mesoderm and the notochord and/or neural tube, arising after segmentation.

Hox-4 gene expression in mouse/chicken heterospecific grafts of signalling regions to limb buds reveals similarities in patterning mechanisms

Development ◽  
1992 ◽  
Vol 115 (2) ◽  
pp. 553-560 ◽  
Author(s):  
J.C. Izpisua-Belmonte ◽  
J.M. Brown ◽  
A. Crawley ◽  
D. Duboule ◽  
C. Tickle
Keyword(s):  
Gene Expression ◽  
Gene Network ◽  
Primitive Streak ◽  
Mouse Embryos ◽  
Limb Bud ◽  
Chick Embryos ◽  
Mouse Limb ◽  
Mouse Cells ◽  
Species Specific ◽  
Genital Tubercle

The products of Hox-4 genes appear to encode position in developing vertebrate limbs. In chick embryos, a number of different signalling regions when grafted to wing buds lead to duplicated digit patterns. We grafted tissue from the equivalent regions in mouse embryos to chick wing buds and assayed expression of Hox-4 genes in both the mouse cells in the grafts and in the chick cells in the responding limb bud using species specific probes. Tissue from the mouse limb polarizing region and anterior primitive streak respecify anterior chick limb bud cells to give posterior structures and lead to activation of all the genes in the complex. Mouse neural tube and genital tubercle grafts, which give much less extensive changes in pattern, do not activate 5′-located Hox-4 genes. Analysis of expression of Hox-4 genes in mouse cells in the grafted signalling regions reveals no relationship between expression of these genes and strength of their signalling activity. Endogenous signals in the chick limb bud activate Hox-4 genes in grafts of mouse anterior limb cells when placed posteriorly and in grafts of mouse anterior primitive streak tissue. The activation of the same gene network by different signalling regions points to a similarity in patterning mechanisms along the axes of the vertebrate body.

Tissue interactions in the organization and maintenance of the muscle pattern in the chick limb

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 199-215
Author(s):  
Annick Mauger ◽  
Madeleine Kieny ◽  
Ihsan Hedayat ◽  
Paul F. Goetinck
Keyword(s):  
Chick Embryos ◽  
Limb Muscle ◽  
Collagen Biosynthesis ◽  
In Ovo ◽  
Avian Embryos ◽  
Tissue Interactions ◽  
Pattern Development ◽  
Somitic Mesoderm ◽  
Putative Mutant ◽  
Muscular Dysgenesis

Recent investigations on a hereditary muscular dysgenesis (cn/cn) in the chicken (Kieny, Mauger, Hedayat & Goetinck, 1983) have suggested that limb muscle pattern development and subsequent maintenance are two independent steps in the formation of the musculature. The respective activities or muscle cells and connective tissue cells in the ontogeny of the musculature have been investigated in avian embryos 1) by in ovo administration of drugs interfering with collagen biosynthesis, and 2) by heterogenetic somite-exchange experiments between normal and mutant embryos. None of the drugs administered to the chick embryo caused any disturbance of muscle pattern formation or maintenance whether treatment occurred before (5 days) or after (7·5 days) the muscle splitting period. Heterogenetic implantations were performed at 2 days of incubation either at the leg or at the wing level. Somitic mesoderm from non-mutant quail embryo was grafted to replace a piece of somitic mesoderm in putative mutant (cn/cn) chick embryos. The introduction of normal myogenic cells into a mutant leg or wing led to a normally patterned musculature, which demonstrates that the muscular dysgenesis cn/cn results from a defect of the somitic myogenic cell line.

scholarly journals Limb-somite relationship: effect of removal of somitic mesoderm on the wing musculature

Development ◽  
1978 ◽  
Vol 43 (1) ◽  
pp. 263-278
Author(s):  
Alain Chevallier ◽  
Madeleine Kieny ◽  
Annick Mauger
Keyword(s):  
The Other ◽  
Chick Embryos ◽  
Forearm Muscles ◽  
X Irradiation ◽  
Both Bones ◽  
Somitic Mesoderm

The aim of this study is to test the ability of the intrinsic wing musculature to develop in the absence of somitic mesoderm. The experiments were performed on 2- to 2.5-day chick embryos either by replacing the somitic mesoderm adjacent to the wing field with a piece of 9-day chick embryonic midgut or by destroying, through local X-irradiation, not only the somitic mesoderm of the wing level, but also at least three somites (or presumptive somites) anterior and/or three presumptive somites posterior to the wing level. The replacement of somitic tissue scarcely affected the organogenesis of the forearm musculature, at least when both bones were present. In the other experiments, radio-destruction severely impaired the development of the forearm muscles, which were seldom all present and in most cases were entirely missing. The absence of a given muscle involves the simultaneous absence of the corresponding tendons. The possible origins of the muscles that formed despite the removal of the somitic mesoderm are discussed.

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