scholarly journals Placozoan fiber cells: mediators of innate immunity and participants in wound healing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tatiana D. Mayorova ◽  
Katherine Hammar ◽  
Jae H. Jung ◽  
Maria A. Aronova ◽  
Guofeng Zhang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Three Dimensional ◽  
Cell Types ◽  
Marine Animals ◽  
Thin Sections ◽  
Fiber Cells ◽  
Trichoplax Adhaerens ◽  
Multiple Processes ◽  
Representative Member

AbstractPlacozoa is a phylum of non-bilaterian marine animals. These small, flat organisms adhere to the substrate via their densely ciliated ventral epithelium, which mediates mucociliary locomotion and nutrient uptake. They have only six morphological cell types, including one, fiber cells, for which functional data is lacking. Fiber cells are non-epithelial cells with multiple processes. We used electron and light microscopic approaches to unravel the roles of fiber cells in Trichoplax adhaerens, a representative member of the phylum. Three-dimensional reconstructions of serial sections of Trichoplax showed that each fiber cell is in contact with several other cells. Examination of fiber cells in thin sections and observations of live dissociated fiber cells demonstrated that they phagocytose cell debris and bacteria. In situ hybridization confirmed that fiber cells express genes involved in phagocytic activity. Fiber cells also are involved in wound healing as evidenced from microsurgery experiments. Based on these observations we conclude that fiber cells are multi-purpose macrophage-like cells. Macrophage-like cells have been described in Porifera, Ctenophora, and Cnidaria and are widespread among Bilateria, but our study is the first to show that Placozoa possesses this cell type. The phylogenetic distribution of macrophage-like cells suggests that they appeared early in metazoan evolution.

scholarly journals Hematopoiesis in 3 dimensions: human and murine bone marrow architecture visualized by confocal microscopy

Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. e41-e55 ◽  
Author(s):  
Tomoiku Takaku ◽  
Daniela Malide ◽  
Jichun Chen ◽  
Rodrigo T. Calado ◽  
Sachiko Kajigaya ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Three Dimensional ◽  
Cell Types ◽  
Bone Marrow Tissue ◽  
Murine Bone Marrow ◽  
3 Dimensional ◽  
Vascular Structures ◽  
Bone Structures ◽  
Surrounding Bone

AbstractIn many animals, blood cell production occurs in the bone marrow. Hematopoiesis is complex, requiring self-renewing and pluripotent stem cells, differentiated progenitor and precursor cells, and supportive stroma, adipose tissue, vascular structures, and extracellular matrix. Although imaging is a vital tool in hematology research, the 3-dimensional architecture of the bone marrow tissue in situ remains largely uncharacterized. The major hindrance to imaging the intact marrow is the surrounding bone structures are almost impossible to cut/image through. We have overcome these obstacles and describe a method whereby whole-mounts of bone marrow tissue were immunostained and imaged in 3 dimensions by confocal fluorescence and reflection microscopy. We have successfully mapped by multicolor immunofluorescence the localization pattern of as many as 4 cell features simultaneously over large tiled views and to depths of approximately 150 μm. Three-dimensional images can be assessed qualitatively and quantitatively to appreciate the distribution of cell types and their interrelationships, with minimal perturbations of the tissue. We demonstrate its application to normal mouse and human marrow, to murine models of marrow failure, and to patients with aplastic anemia, myeloid, and lymphoid cell malignancies. The technique should be generally adaptable for basic laboratory investigation and for clinical diagnosis of hematologic diseases.

scholarly journals Three-dimensional electron microscopy of ribosomal chromatin in two higher plants: a cytochemical, immunocytochemical, and in situ hybridization approach.

1991 ◽  
Vol 39 (11) ◽  
pp. 1495-1506 ◽  
Author(s):  
P M Motte ◽  
R Loppes ◽  
M Menager ◽  
R Deltour
Keyword(s):  
Electron Microscopy ◽  
In Situ Hybridization ◽  
Spatial Organization ◽  
Higher Plants ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Thin Sections ◽  
Cytoplasmic Dna ◽  
Immunocytochemical Techniques

We report the 3-D arrangement of DNA within the nucleolar subcomponents from two evolutionary distant higher plants, Zea mays and Sinapis alba. These species are particularly convenient to study the spatial organization of plant intranucleolar DNA, since their nucleoli have been previously reconstructed in 3-D from serial ultra-thin sections. We used the osmium ammine-B complex (a specific DNA stain) on thick sections of Lowicryl-embedded root fragments. Immunocytochemical techniques using anti-DNA antibodies and rDNA/rDNA in situ hybridization were also applied on ultra-thin sections. We showed on tilted images that the OA-B stains DNA throughout the whole thickness of the section. In addition, very low quantities of cytoplasmic DNA were stained by this complex, which is now the best DNA stain used in electron microscopy. Within the nucleoli the DNA was localized in the fibrillar centers, where large clumps of dense chromatin were also visible. In the two plant species intranucleolar chromatin forms a complex network with strands partially linked to chromosomal nucleolar-organizing regions identified by in situ hybridization. This study describes for the first time the spatial arrangement of the intranucleolar chromatin in nucleoli of higher plants using high-resolution techniques.

scholarly journals In situelectro-sequencing in three-dimensional tissues

2021 ◽  
Author(s):  
Qiang Li ◽  
Zuwan Lin ◽  
Ren Liu ◽  
Xin Tang ◽  
Jiahao Huang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Single Cell ◽  
Three Dimensional ◽  
Cell Types ◽  
Developmental Trajectory ◽  
Single Cell Level ◽  
Cell Level ◽  
Cell Gene Expression ◽  
Cell Gene

AbstractPairwise mapping of single-cell gene expression and electrophysiology in intact three-dimensional (3D) tissues is crucial for studying electrogenic organs (e.g., brain and heart)1–5. Here, we introducein situelectro-sequencing (electro-seq), combining soft bioelectronics within situRNA sequencing to stably map millisecond-timescale cellular electrophysiology and simultaneously profile a large number of genes at single-cell level across 3D tissues. We appliedin situelectro-seq to 3D human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) patches, precisely registering the CM gene expression with electrophysiology at single-cell level, enabling multimodalin situanalysis. Such multimodal data integration substantially improved the dissection of cell types and the reconstruction of developmental trajectory from spatially heterogeneous tissues. Using machine learning (ML)-based cross-modal analysis,in situelectro-seq identified the gene-to-electrophysiology relationship over the time course of cardiac maturation. Further leveraging such a relationship to train a coupled autoencoder, we demonstrated the prediction of single-cell gene expression profile evolution using long-term electrical measurement from the same cardiac patch or 3D millimeter-scale cardiac organoids. As exemplified by cardiac tissue maturation,in situelectro-seq will be broadly applicable to create spatiotemporal multimodal maps and predictive models in electrogenic organs, allowing discovery of cell types and gene programs responsible for electrophysiological function and dysfunction.

Immunoelectron microscopy of the intracellular compartments of prespore cells of dictyostelium discoideum

1990 ◽  
Vol 48 (3) ◽  
pp. 606-607
Author(s):  
Gregory W. Erdos ◽  
Bonnie J. O'Brien ◽  
Christopher M. West
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Dense Layer ◽  
Slime Molds ◽  
Thin Sections ◽  
Dimensional Reconstruction ◽  
Intracellular Compartments ◽  
Cellular Slime ◽  
Secretory System ◽  
Acidic Compartments

In the amoeboid cellular slime molds two cell types are formed during differentiation, prestalk cells and prespore cells which ultimately become the stalk and spore cells of the mature sorocarp. The prespore cells can be identified ultrastructurally by the prespore vesicles (PSV), which have a dense layer lining the inside of the compartment (Fig. 1). The PSV's are known to contain several glycoproteins and a galactose polysaccharide that are released to the cell surface to become major components of the spore coat. Further investigations in this laboratory, by three dimensional reconstruction from serial thin sections and by confocal fluorescence microscopy have shown that the PSV's are not a collection of separate vesicles, but rather a tubular reticulum asymmetrically disposed in the cell. Similar geometry has been shown for some lysosomal systems. A recent report has shown that the lysosomal enzyme, α-mannosidase, can be localized to the PSV. These pieces of evidence suggest a possible lysosomal function or lysosomal origin for the prespore secretory system. In an effort to better characterize the PSV compartment we have chosen two monoclonal antibodies, 5G7 which recognizes a common lysosomal epitope and 81.2 which recognizes a carbohydrate epitope on the plasma membrane and on compartments of phagocytotic and autophagic origin. We further chose to characterize the distribution of acidic compartments using the DAMP method of Anderson, which would give us an indication of functional lysosomal activity.

scholarly journals THE FINE STRUCTURE OF CORTICAL COMPONENTS OF PARAMECIUM MULTIMICRONUCLEATUM

1955 ◽  
Vol 1 (6) ◽  
pp. 583-604 ◽  
Author(s):  
Albert W. Sedar ◽  
Keith R. Porter
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Basal Body ◽  
Three Dimensional ◽  
Cell Types ◽  
The Body ◽  
Fiber System ◽  
Thin Sections ◽  
Ciliary Membrane ◽  
The Matrix

The electron microscope was used to study the structure and three dimensional relationships of the components of the body cortex in thin sections of Paramecium multimicronucleatum. Micrographs of sections show that the cortex is covered externally by two closely apposed membranes (together ∼250 A thick) constituting the pellicle. Beneath the pellicle the surface of the animal is molded into ridges that form a polygonal ridgework with depressed centers. It is these ridges that give the surface of the organism its characteristic configuration and correspond to the outer fibrillar system of the light microscope image. The outer ends of the trichocysts with their hood-shaped caps are located in the centers of the anterior and posterior ridges of each polygon. The cilia extend singly from the depressed centers of the surface polygons. Each cilium shows two axial filaments with 9 peripheral and parallel filaments embedded in a matrix and the whole surrouned by a thin ciliary membrane. The 9 peripheral filaments are double and these are evenly spaced in a circle around the central pair. The ciliary membrane is continuous with the outer member of the pellicular membrane, whereas the plasma membrane is continuous with the inner member of the pellicular membrane. At the level of the plasma membrane the proximal end of the cilium is continuous with its tube-shaped basal body or kinetosome. The peripheral filaments of the cilium, together with the material of cortical matrix which tends to condense around them, form the sheath of the basal body. The kinetodesma connecting the ciliary kinetosomes (inner fibrillar system of the light microscopist) is composed of a number of discrete fibrils which overlap in a shingle-like fashion. Each striated kinetosomal fibril originates from a ciliary kinetosome and runs parallel to other kinetosomal fibrils arising from posterior kinetosomes of a particular meridional array. Sections at the level of the ciliary kinetosomes reveal an additional fiber system, the infraciliary lattice system, which is separate and distinct from the kinetodesmal system. This system consists of a fibrous network of irregular polygons and runs roughly parallel to the surface of the animal. Mitochondria have a fine structure similar in general features to that described for a number of mammalian cell types, but different in certain details. The structures corresponding to cristae mitochondriales appear as finger-like projections or microvilli extending into the matrix of the organelle from the inner membrane of the paired mitochondrial membrane. The cortical cytoplasm contains also a particulate component and a system of vesicles respectively comparable to the nucleoprotein particles and to the endoplasmic reticulum described in various metazoan cell types. An accessory kinetosome has been observed in oblique sections of a number of non-dividing specimens slightly removed from the ciliary kinetosome and on the same meridional line as the cilia and trichocysts. Its position corresponds to the location of the kinetosome of the newly formed cilium in animals selected as being in the approaching fission stage of the life cycle.

Three Dimensional Immuno-Localization of Green Fluorescent Protein Chimeras Using Rapid Freezing and Freeze-Substitution

2000 ◽  
Vol 6 (S2) ◽  
pp. 298-299
Author(s):  
Mary Morphew ◽  
David Mastronarde ◽  
Eileen O'Toole ◽  
Mark Ladinsky ◽  
Brad Marsh ◽  
...  
Keyword(s):  
Low Temperature ◽  
Fluorescent Protein ◽  
Three Dimensional ◽  
Freeze Substitution ◽  
Cell Types ◽  
Uranyl Acetate ◽  
Rapid Freezing ◽  
Thin Sections ◽  
Green Fluorescent ◽  
Structural Preservation

All microscopy is limited by the quality of the specimen under study. Three-dimensional (3-D) visualization of antigen localization using the electron microscope (EM) is particularly challenging due to the need to maintain the activity of some epitopes while preserving cellular ultrastructure. We have used rapid freezing to immobilize all cellular constituents almost instantaneously. Freeze-substitution of the frozen samples was used to stabilize the specimen and to accomplish low-temperature dehydration, minimizing perturbation of cellular structure. We have found that high pressure freezing, double jet freezing and plunge freezing are all useful for achieving high quality structural preservation for some cell types or for particular applications. For immunolocalization, we have had most success freeze-substituting into acetone containing 0.2% glutaraldehyde and 0.1 % uranyl acetate. We have utilized low-temperature acrylic embedding resins, Lowicryl HM20 and LRGold, to further maintain structure and decrease protein insolubility. Both of these resins have proven suitable for cutting serial thin sections.

Detection of mRNAGFAP by post-embedding EM in situ hybridization

1990 ◽  
Vol 48 (3) ◽  
pp. 746-747
Author(s):  
Page A. Erickson ◽  
Stuart C. Feinstein ◽  
Geoffrey P. Lewis ◽  
Steven K. Fisher
Keyword(s):  
In Situ Hybridization ◽  
Cell Types ◽  
Thin Sections ◽  
Retinal Astrocytes ◽  
Gfap Expression ◽  
Gold Conjugate ◽  
Lowicryl K4m ◽  
Different Cell Types ◽  
Precursor Mrna

We have developed a technique that allows mRNA molecules to be localized within cells at extremely high (nanometer) resolution. Using a cDNA for glial fibrillary acidic protein (GFAP forms lOnm diameter intermediate filaments), we have localized the mRNAGFAP in three different cell types (optic nerve astrocytes, retinal astrocytes and retinal Miiller cells). One retina was experimentally detached to stimulate GFAP expression in retinal Miiller cells. Cells containing GFAP were identified by immunoelectron microscopy. Cat retinas and optic nerves (n=7) were fixed with 2% or 4% paraformaldehyde for 1.0 hr, dehydrated with dimethylformamide, and embedded in Lowicryl K4M resin. Thin sections, placed on nickel grids, were probed with biotinylated cDNAGFAP (overnight at 37°C) followed by streptavidin-gold conjugate (1.0 hr, 23°C).In each of the three cell types that contain GFAP, the localization of the mRNAGFAP was the same. In the nuclei gold spheres were localized over amorphous, electron-dense regions within the euchromatin (presumably precursor mRNA).

scholarly journals Electron microscopic autoradiographic localization of prolactin mRNA in rat pituitary.

1989 ◽  
Vol 37 (5) ◽  
pp. 567-571 ◽  
Author(s):  
Y Tong ◽  
H F Zhao ◽  
J Simard ◽  
F Labrie ◽  
G Pelletier
Keyword(s):  
In Situ Hybridization ◽  
Secretory Granules ◽  
Cdna Probe ◽  
Cell Types ◽  
Hybridization Technique ◽  
Experimental Conditions ◽  
Thin Sections ◽  
Rat Pituitary ◽  
Silver Grains

Recent immunoelectron microscopic studies have shown that immunoreactive prolactin (PRL) in rat pituitary can be detected not only in typical PRL cells, characterized by large secretory granules, but also in another type of cell, which contains small secretory granules. To determine whether or not these two cell types are involved in PRL biosynthesis, we developed a procedure to investigate PRL gene expression by using in situ hybridization at the ultrastructural level. Rat pituitary was fixed and vibratome sections were incubated with a PRL [35S]-cDNA probe and subsequently flat-embedded in Araldite. Semi-thin and ultra-thin sections were processed for autoradiography. The results indicate that only the two PRL cell types were labeled. When immunolabeling for PRL was applied to ultra-thin sections, only immunopositive cells were seen to contain silver grains. In these cells the silver grains were associated with the rough endoplasmic reticulum and nucleus. When a growth hormone (GH) [35S]-cDNA probe was used as a control, only GH-secreting cells were labeled. This study confirms that the two PRL cell types are involved in biosynthesis of PRL. Moreover, this simple in situ hybridization technique provides a new approach to accurately localize mRNA in complex tissue and to investigate the subcellular distribution of mRNA under differing experimental conditions.

scholarly journals The radial expression of dorsal-ventral patterning genes in placozoans, Trichoplax adhaerens, argues for an oral-aboral axis

2018 ◽  
Author(s):  
Timothy Q. DuBuc ◽  
Yuriy Bobkov ◽  
Joseph Ryan ◽  
Mark Q. Martindale
Keyword(s):  
Expression Patterns ◽  
Model Organism ◽  
Cell Types ◽  
Marine Animals ◽  
Axial Patterning ◽  
Trichoplax Adhaerens ◽  
Distinct Cell ◽  
Tgfb Signaling ◽  
Relationship Of ◽  
The Relationship

AbstractThe placozoans are a morphologically simplistic group of marine animals found globally in tropical and subtropical environments. They consist of a single named species, Trichoplax adhaerens and have roughly six morphologically distinct cell types. With a sequenced genome, a limited number of cell-types and a simple flattened morphology, Trichoplax is an ideal model organism to understand cellular dynamics and tissue patterning in the first animals. Using new approaches for identification of gene expression patterns this research looks at the relationship of Chordin/TgfB signaling and the axial patterning system of Placozoa. Our results suggest that placozoans have an oral-aboral axis similar to cnidarians and that the parahoxozoan ancestor (common ancestor of Placozoa and Cnidaria) was likely radially symmetric.

scholarly journals ‘Venus trapped, Mars transits': Cu and Fe redox chemistry, cellular topography and in situ ligand binding in terrestrial isopod hepatopancreas

Open Biology ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 150270
Author(s):  
P. Kille ◽  
A. J. Morgan ◽  
K. Powell ◽  
J. F. W. Mosselmans ◽  
D. Hart ◽  
...  
Keyword(s):  
B Cells ◽  
Bond Length ◽  
Cell Types ◽  
Thin Sections ◽  
X Ray ◽  
Nocturnal Feeding ◽  
Fe Speciation ◽  
Dietary Components ◽  
Morphological Relationship

Woodlice efficiently sequester copper (Cu) in ‘cuprosomes' within hepatopancreatic ‘S' cells. Binuclear ‘B’ cells in the hepatopancreas form iron (Fe) deposits; these cells apparently undergo an apocrine secretory diurnal cycle linked to nocturnal feeding. Synchrotron-based µ-focus X-ray spectroscopy undertaken on thin sections was used to characterize the ligands binding Cu and Fe in S and B cells of Oniscus asellus (Isopoda). Main findings were: (i) morphometry confirmed a diurnal B-cell apocrine cycle; (ii) X-ray fluorescence (XRF) mapping indicated that Cu was co-distributed with sulfur (mainly in S cells), and Fe was co-distributed with phosphate (mainly in B cells); (iii) XRF mapping revealed an intimate morphological relationship between the basal regions of adjacent S and B cells; (iv) molecular modelling and Fourier transform analyses indicated that Cu in the reduced Cu + state is mainly coordinated to thiol-rich ligands (Cu–S bond length 2.3 Å) in both cell types, while Fe in the oxidized Fe 3+ state is predominantly oxygen coordinated (estimated Fe–O bond length of approx. 2 Å), with an outer shell of Fe scatterers at approximately 3.05 Å; and (v) no significant differences occur in Cu or Fe speciation at key nodes in the apocrine cycle. Findings imply that S and B cells form integrated unit-pairs; a functional role for secretions from these cellular units in the digestion of recalcitrant dietary components is hypothesized.

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