Behavioural properties of chick somitic mesoderm and lateral plate when explanted in vitro

Development ◽  
1980 ◽  
Vol 56 (1) ◽  
pp. 41-58
Author(s):  
Ruth Bellairs ◽  
P. A. Portch ◽  
E. J. Sanders
Keyword(s):  
Time Lapse ◽  
Lateral Plate Mesoderm ◽  
General Shape ◽  
Electron Microscopic ◽  
Lateral Plate ◽  
Plastic Substrates ◽  
Different Types ◽  
Somitic Mesoderm ◽  
Microscopic Techniques

Tissue culture, time-lapse cinematographic and electron microscopic techniques have been used to study the properties of chick mesoderm at several stages of differentiation. Lateral plate, unsegmented mesoderm (segmental plate), and newly formed somites were dissected from stage-12 embryos, whilst dermo-myotomes and sclerotomes were dissected from stage-18 embryos. Each type of mesoderm was found to exhibit a characteristic pattern of behaviour. The explants from the unsegmented mesoderm, from the newly formed somites and from the older embryos could be placed in a developmental sequence; with increasing differentiation they settled and spread on the substrate more readily, whether explanted as pieces of tissue or as individual cells, and it was concluded that this implied an increased adhesion to the substrate. Similarly, with increasing differentiation, the cells segmented at a faster rate. No significant differences could be discerned in the internal structure of the different types of cells, although differences in the general shape were apparent. The lateral plate mesoderm cells, which bear some resemblances to the unsegmented mesoderm cells in the embryo, also show some morphological resemblances to them in vitro. However, the lateral plate cells had a much greater success in attaching to glass or plastic substrates. They were also found to have the highest speed of locomotion of all the tissues studied, whereas the unsegmented had the lowest. It is concluded therefore, that although cells may look similar to one another morphologically, their behaviour may differ greatly, probably because they are already partially determined.

scholarly journals Motility of bile canaliculi in the living animal: implications for bile flow.

1991 ◽  
Vol 113 (5) ◽  
pp. 1069-1080 ◽  
Author(s):  
N Watanabe ◽  
N Tsukada ◽  
C R Smith ◽  
M J Phillips
Keyword(s):  
Bile Flow ◽  
Cytochalasin B ◽  
Time Lapse ◽  
Sodium Fluorescein ◽  
Branch Points ◽  
Bile Canaliculi ◽  
Enhanced Fluorescence ◽  
Microscopic Techniques

Modern fluorescence microscopic techniques were used to image the bile canalicular system in the intact rat liver, in vivo. By combining the use of sodium fluorescein secretion into bile, with digitally enhanced fluorescence microscopy and time-lapse video, it was possible to capture and record the canalicular motility events that accompany the secretion of bile in life. Active bile canalicular contractions were found predominantly in zone 1 (periportal) hepatocytes of the liver. The contractile movements were repetitive, forceful, and appeared unidirectional moving bile in a direction towards the portal bile ducts. Contractions were not seen in the network of canaliculi on the surface of the liver. Cytochalasin B administration resulted in reduced canalicular motility, progressive dilation of zone 1 canaliculi, and impairment of bile flow. Canalicular dilations invariably involved the branch points of the canalicular network. The findings add substantively to previous in vitro studies using couplets, and suggest that canalicular contractions contribute physiologically to bile flow in the liver.

scholarly journals Are cross-bridging structures involved in the bundle formation of intermediate filaments and the decrease in locomotion that accompany cell aging?

1985 ◽  
Vol 100 (5) ◽  
pp. 1466-1473 ◽  
Author(s):  
E Wang
Keyword(s):  
Intermediate Filaments ◽  
Electron Microscopic Examination ◽  
Time Lapse ◽  
Cell Aging ◽  
Electron Microscopic ◽  
Cell Locomotion ◽  
Wide Range ◽  
Filament Bundles ◽  
Large Filament

Five different fibroblast strains derived from donors of a wide range of ages were used for investigation of senescence-associated changes in the organization of intermediate filaments (IFs) and the activity of cell locomotion. Results of immunofluorescence microscopy demonstrate that, in large and flat in vitro aged fibroblasts, vimentin-containing IFs are distributed as unusually organized large bundles. Electron microscopic examination shows that these large bundles are indeed composed of filaments of 8-10 nm. Such a profile of large bundles is rarely seen in young fibroblasts whose IFs are usually interdispersed among microtubules. Within the large filament bundles of senescent fibroblasts, cross-bridge-like extensions are frequently observed along the individual IFs. Immunogold labeling with antibody to one of the cross-bridging proteins, p50, further illustrates the abundance of interfilament links within the IF bundles. The senescence-related increase in interfilament association was also supported by the results of co-precipitation between vimentin and an associated protein of 50,000 D. Time-lapse cinematographic studies of cell locomotion reveal that accompanying aging, fibroblasts have a significantly reduced ability to translocate across a solid substratum. These results led me to suggest that the increased interfilament links via cross-bridges may in part contribute to the mechanism that orchestrates the formation of large filament bundles. The presence of enormous bundles in the cytoplasm may physically impede the efficiency of locomotion for these nondividing cells.

In Vitro Studies of Microtubule Structures Using the Mac Mode AFM

1999 ◽  
Vol 5 (S2) ◽  
pp. 1006-1007
Author(s):  
J. Zhu ◽  
J. Hartman ◽  
R. Case ◽  
S. Rice ◽  
R. Vale
Keyword(s):  
Structural Unit ◽  
Electron Microscopic ◽  
Physiological Conditions ◽  
Atomic Force ◽  
Chromosome Separation ◽  
Cytoplasmic Microtubules ◽  
Dynamic Structures ◽  
Microscopic Techniques ◽  
Β Tubulin

Microtubules are long, hollow, stiff polymers that extend throughout the cytoplasm. They are involved in such diverse functions as governing the location of membrane-bounded organelles and chromosome separation during mitosis. The basic structural unit is tubulin, which is a heterodimer consisting of two closely related and tightly linked globular polypeptides called α and β-tubulin. Alternating α and β tubulin subunits form protofilaments, 13 of which bundle around a central core to form microtubule. The detailed structures of cytoplasmic microtubules have been studied extensively using various electron microscopic techniques. As microtubules are dynamic structures in constant transitions between growing and shrinking phases, it would be extremely interesting to investigate the structural organization of the subunit tubulin molecules in a buffer close to physiological conditions. With its high resolution and ability to image in fluid, atomic force microscope (AFM) makes it possible to study the biological structures in a native environment.

scholarly journals Human iPS-derived pre-epicardial cells direct cardiomyocyte aggregation expansion and organization in vitro

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Jie Tan ◽  
Jacques P. Guyette ◽  
Kenji Miki ◽  
Ling Xiao ◽  
Gurbani Kaur ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Spatial Organization ◽  
Three Dimensional ◽  
Calcium Handling ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Epicardial Cells ◽  
Tissue Organization ◽  
Cell Layers

AbstractEpicardial formation is necessary for normal myocardial morphogenesis. Here, we show that differentiating hiPSC-derived lateral plate mesoderm with BMP4, RA and VEGF (BVR) can generate a premature form of epicardial cells (termed pre-epicardial cells, PECs) expressing WT1, TBX18, SEMA3D, and SCX within 7 days. BVR stimulation after Wnt inhibition of LPM demonstrates co-differentiation and spatial organization of PECs and cardiomyocytes (CMs) in a single 2D culture. Co-culture consolidates CMs into dense aggregates, which then form a connected beating syncytium with enhanced contractility and calcium handling; while PECs become more mature with significant upregulation of UPK1B, ITGA4, and ALDH1A2 expressions. Our study also demonstrates that PECs secrete IGF2 and stimulate CM proliferation in co-culture. Three-dimensional PEC-CM spheroid co-cultures form outer smooth muscle cell layers on cardiac micro-tissues with organized internal luminal structures. These characteristics suggest PECs could play a key role in enhancing tissue organization within engineered cardiac constructs in vitro.

An Analysis of the Postgastrula Differentiation of the Hypomere

Development ◽  
1962 ◽  
Vol 10 (3) ◽  
pp. 293-314
Author(s):  
Cyril V. Finnegan
Keyword(s):  
Normal Development ◽  
Deep Layer ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Self Differentiation ◽  
Axial System ◽  
Require Information

Following its involution around the lateral lips of the blastopore, the potential hypomere (lateral plate mesoderm) of Urodeles undergoes a dorsal convergence, along with other portions of the mesoderm mantle and then, during neurulation, initiates an independent ventrad migration (Nieuwkoop, 1947). As the hypomere migrates ventrally, it becomes further removed from the influences shown by Yamada (1950) to emanate from the mid-dorsal axial system and its deep layer is in contact with a tissue (endoderm) which seems to be influential in the differentiation of this mesoderm (Bacon, 1945; Jacobson, 1960; Nieuwkoop, 1947, 1950; Finnegan, 1953, 1955, 1961a, 1961b). A further understanding of the postgastrula development of the trunk hypomere seemed to require information of the possible restriction, in time, of the competence of this mesoderm or, alternatively, its degree of self-differentiation within an embryonic system for in vitro observations may indicate histogenetic potencies unrelated to normal development (Finnegan, 1961a, 1961b).

Persistent myogenic capacity of the dermomyotome dorsomedial lip and restriction of myogenic competence

Development ◽  
2002 ◽  
Vol 129 (16) ◽  
pp. 3873-3885 ◽  
Author(s):  
Sara J. Venters ◽  
Charles P. Ordahl
Keyword(s):  
Primary Source ◽  
The Body ◽  
Paraxial Mesoderm ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Myogenic Potential ◽  
Epithelial Sheet ◽  
Mechanistic Basis ◽  
Somitic Mesoderm ◽  
Serial Transplantation

The dorsomedial lip (DML) of the somite dermomyotome is the source of cells for the early growth and morphogenesis of the epaxial primary myotome and the overlying dermomyotome epithelium. We have used quail-chick transplantation to investigate the mechanistic basis for DML activity. The ablated DML of chick wing-level somites was replaced with tissue fragments from various mesoderm regions of quail embryos and their capacity to form myotomal tissue assessed by confocal microscopy. Transplanted fragments from the epithelial sheet region of the dermomyotome exhibited full DML growth and morphogenetic capacity. Ventral somite fragments (sclerotome), head paraxial mesoderm or non-paraxial (lateral plate) mesoderm tested in this assay were each able to expand mitotically in concert with the surrounding paraxial mesoderm, although no myogenic potential was evident. When ablated DMLs were replaced with fragments of the dermomyotome ventrolateral lip of wing-level somites or pre-somitic mesoderm (segmental plate), myotome development was evident but was delayed or otherwise limited in some cases. Timed DML ablation-replacement experiments demonstrate that DML activity is progressive throughout the embryonic period (to at least E7) and its continued presence is necessary for the complete patterning of each myotome segment. The results of serial transplantation and BrdU pulse-chase experiments are most consistent with the conclusion that the DML consists of a self-renewing population of progenitor cells that are the primary source of cells driving the growth and morphogenesis of the myotome and dermomyotome in the epaxial domain of the body.

The control of pigment cell pattern formation in the California newt, Taricha torosa

Development ◽  
1986 ◽  
Vol 97 (1) ◽  
pp. 141-168
Author(s):  
R. P. Tucker ◽  
C. A. Erickson
Keyword(s):  
Neural Crest ◽  
Pigment Cell ◽  
Contact Inhibition ◽  
Pigment Cells ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Pronephric Duct ◽  
Taricha Torosa ◽  
Dorsal Stripe

Neural crest-derived pigment cells form species-specific patterns of pigmentation in amphibian embryos. We have characterized the appearance and changes in pigment cell distribution in the embryos of the California newt, Taricha torosa. Black melanophores first appear scattered over the surface of the somites intermingled with yellow xanthophores in stage 34/35 embryos. The melanophores then migrate either dorsally to form a dorsal stripe at the apex of the somites or ventrally along the intersomitic furrows to form a midbody stripe at the somite—lateral plate mesoderm border. Xanthophores remain between the two melanophore stripes and are also found in the dorsal fin and head. The formation of the dorsal stripe coincides with a change in melanophore tissue affinity from the surface of the somites to the subectodermal extracellular matrix (ECM). The latter substratum is the location of the cue used to organize the dorsal stripe. In addition, melanophores become elongate and highly arborized, which would allow them to extend to the region where the dorsal stripe forms. In contrast, xanthophores do not form long processes in vitro. This suggests that the ability of melanophores but not xanthophores to search for a cue at the apex of the somites may account in part for the segregation of these cells types. Melanophores and xanthophores are trapped to form the midbody stripe by the pronephric duct, which is located just beneath the ectoderm at the bases of the intersomitic furrows. Ablation of the duct prevents formation of the midbody stripe, although melanophores and xanthophores still fail to migrate ventrally over the lateral plate mesoderm. Melanophores grafted to the ventral midline fail to leave the confines of the donor tissue. This suggests that a factor in the lateral plate mesoderm in addition to the pronephric duct is inhibiting further ventral migration. There is no gross morphological difference in the organization of the subectodermal ECM dorsal and ventral to the pronephric duct as revealed by alcian blue, ruthenium red and staining with antibodies to fibronectin. We also conclude that the directed dispersal of the neural crest into the space between the somites and ectoderm is due to contact inhibition of cell movement, since T. torosa neural crest cells demonstrate contact inhibition in vitro and there are enough cells in the lateral migratory spaces to make contact events likely during dispersal.

The Function of the Basal Filaments in the Parietal Layer of Bowman's Capsule

1973 ◽  
Vol 51 (2) ◽  
pp. 53-60 ◽  
Author(s):  
W. A. Webber ◽  
W. T. Wong
Keyword(s):  
Cell Types ◽  
Electron Microscopic ◽  
Structural Framework ◽  
Renal Cortical Tissue ◽  
Attachment Mechanism ◽  
Relationship Of ◽  
Bowman's Capsule ◽  
Microscopic Techniques

A number of cell types in the nephron have been known for some time to contain basally located filaments demonstrable by a variety of both light and electron microscopic techniques.]t has been proposed that these filaments may provide a contractile mechanism which would have implications for the control of renal function. One site in which these filaments have been observed is in the parietal layer of Bowman's capsule. The present study was designed to see if contraction of this layer of cells could be demonstrated and if so whether the basal filaments appeared to play a role in the process. Renal cortical tissue was fixed both in vivo and in vitro in the presence and absence of histamine, adrenaline, and acetylcholine and examined by conventional electron microscopic techniques. Basal folding of the cell membrane was observed particularly in the adrenaline-treated tissue and was interpreted as reflecting a conformational change in the cell such as might be expected with contraction. The relationship of this folding, however, to the arrangement of the basal filaments was such as to suggest that contraction of the filaments was not responsible for the folding observed. Alternative roles for the fibrils either as a structural framework or as a component in an attachment mechanism of the cells to the underlying basement membrane were therefore proposed.

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