Adhesion and spreading of Limulus blood cells on artificial surfaces

1980 ◽  
Vol 44 (1) ◽  
pp. 243-262
Author(s):  
P.B. Armstrong
Keyword(s):  
Blood Cells ◽  
Horseshoe Crab ◽  
Time Lapse ◽  
Cell Type ◽  
Marked Contrast ◽  
Limulus Amoebocyte Lysate ◽  
Motile Cells ◽  
Cell Substrate ◽  
Absolute Requirement ◽  
Single Cell Type

The horseshoe crab Limulus has a single cell type in the blood, the granular amoebocyte. These cells, which are non-adhesive and non-motile in the blood, transform to an adhesive and motile state following extravasation. In the present study, the events of transformation were studied by time-lapse microcinematography of cells plated on to glass. Following attachment of cells to the glass, the cells protrude filopods and engage in active motility. Motile cells show 2 convertible forms; a contracted form and a reversibly flattened form. Eventually the motile cells undergo irreversible flattening which is accompanied by spontaneous degranulation. The shapes of irreversibly spread cells are influenced by the arrangement of cell-substrate contacts established prior to degranulation, and by the pattern of contact of domains of granule-derived membrane introduced into the cell surface during granule exocytosis and their subsequent endoctyosis by the cell. The clottable protein released by spontaneous degranulation of the amoebocytes undergoes gelation in the absence of bacterial endotoxin. The ability to undergo spontaneous gelation stands in marked contrast to the absolute requirement for endotoxin for gelation of the clottable protein present in ‘Limulus amoebocyte lysate’, a commercially valuable preparation obtained from amoebocytes used to detect endotoxin.

scholarly journals Heterogeneity in dog red blood cells: sodium and potassium transport.

1979 ◽  
Vol 73 (1) ◽  
pp. 61-71 ◽  
Author(s):  
V Castranova ◽  
J F Hoffman
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Cell Types ◽  
Red Cells ◽  
Cell Type ◽  
Volume Dependence ◽  
Single Cell Type ◽  
Cell Volumes ◽  
K Permeability ◽  
Sodium And Potassium

After incubation in isotonic KCl, dog red blood cells can be separated by centrifugation into subgroups which assume different cell volumes and possess different transport characteristics. Those red cells which swell in isotonic KCl exhibit a higher permeability to K and possess a greater volume dependence for transport of K than those red cells which shrink. A high Na permeability characterizes cells which shrink in isotonic KCl and these cells exhibit a larger volume-dependent Na flux than those red cells which swell. These two subgroups of red cells do not seem to represent two cell populations of different age. The results indicate that the population of normal cells is evidently heterogeneous in that the volume-dependent changes in Na and K permeability are distributed between differnt cell types rather than representing a single cell type which reciprocally changes its selectivity to Na and K.

scholarly journals Cell-type-specific profiling of loaded miRNAs from Caenorhabditis elegans reveals spatial and temporal flexibility in Argonaute loading

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Christopher A. Brosnan ◽  
Alexander J. Palmer ◽  
Steven Zuryn
Keyword(s):  
Caenorhabditis Elegans ◽  
Regulatory Networks ◽  
Regulatory Mechanisms ◽  
Cell Type ◽  
A Genome ◽  
Temporal Flexibility ◽  
Small Regulatory Rnas ◽  
Cell Type Specific ◽  
Single Cell Type ◽  
Regulated Gene Expression

AbstractMulticellularity has coincided with the evolution of microRNAs (miRNAs), small regulatory RNAs that are integrated into cellular differentiation and homeostatic gene-regulatory networks. However, the regulatory mechanisms underpinning miRNA activity have remained largely obscured because of the precise, and thus difficult to access, cellular contexts under which they operate. To resolve these, we have generated a genome-wide map of active miRNAs in Caenorhabditis elegans by revealing cell-type-specific patterns of miRNAs loaded into Argonaute (AGO) silencing complexes. Epitope-labelled AGO proteins were selectively expressed and immunoprecipitated from three distinct tissue types and associated miRNAs sequenced. In addition to providing information on biological function, we define adaptable miRNA:AGO interactions with single-cell-type and AGO-specific resolution. We demonstrate spatial and temporal dynamicism, flexibility of miRNA loading, and suggest miRNA regulatory mechanisms via AGO selectivity in different tissues and during ageing. Additionally, we resolve widespread changes in AGO-regulated gene expression by analysing translatomes specifically in neurons.

scholarly journals NaCl Promotes the Efficient Formation of Haematococcus pluvialis Nonmotile Cells under Phosphorus Deficiency

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 337
Author(s):  
Feng Li ◽  
Ning Zhang ◽  
Yulei Zhang ◽  
Qingsheng Lian ◽  
Caiying Qin ◽  
...  
Keyword(s):  
Haematococcus Pluvialis ◽  
Phosphorus Deficiency ◽  
Cell Formation ◽  
Animal Nutrition ◽  
Cell Factory ◽  
Cell Type ◽  
Negative Effects ◽  
Related Factors ◽  
Motile Cells ◽  
Application Prospects

Natural astaxanthin helps reduce the negative effects caused by oxidative stress and other related factors, thereby minimizing oxidative damage. Therefore, it has considerable potential and broad application prospects in human health and animal nutrition. Haematococcus pluvialis is considered to be the most promising cell factory for the production of natural astaxanthin. Previous studies have confirmed that nonmotile cells of H. pluvialis are more tolerant to high intensity of light than motile cells. Cultivating nonmotile cells as the dominant cell type in the red stage can significantly increase the overall astaxanthin productivity. However, we know very little about how to induce nonmotile cell formation. In this work, we first investigated the effect of phosphorus deficiency on the formation of nonmotile cells of H. pluvialis, and then investigated the effect of NaCl on the formation of nonmotile cells under the conditions of phosphorus deficiency. The results showed that, after three days of treatment with 0.1% NaCl under phosphorus deficiency, more than 80% of motile cells had been transformed into nonmotile cells. The work provides the most efficient method for the cultivation of H. pluvialis nonmotile cells so far, and it significantly improves the production of H. pluvialis astaxanthin.

scholarly journals Author Correction: iLoF: An intelligent Lab on Fiber Approach for Human Cancer Single-Cell Type Identification

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joana S. Paiva ◽  
Pedro A. S. Jorge ◽  
Rita S. R. Ribeiro ◽  
Meritxell Balmaña ◽  
Diana Campos ◽  
...  
Keyword(s):  
Single Cell ◽  
Human Cancer ◽  
Cell Type ◽  
Single Cell Type

Differential calcium signalling by m2 and m3 muscarinic acetylcholine receptors in a single cell type

1995 ◽  
Vol 352 (5) ◽  
pp. 469-476 ◽  
Author(s):  
Martina Schmidt ◽  
Christine Bienek ◽  
Chris J. van Koppen ◽  
Martin C. Michel ◽  
Karl H. Jakobs
Keyword(s):  
Single Cell ◽  
Acetylcholine Receptors ◽  
Calcium Signalling ◽  
Muscarinic Acetylcholine Receptors ◽  
Cell Type ◽  
Muscarinic Acetylcholine ◽  
Single Cell Type

Motility of the Limulus blood cell

1979 ◽  
Vol 37 (1) ◽  
pp. 169-180
Author(s):  
P.B. Armstrong
Keyword(s):  
Tissue Culture ◽  
Time Lapse ◽  
Coelomic Fluid ◽  
Cellular Motility ◽  
Paraffin Oil ◽  
Motile Cells ◽  
Direct Microscopic Examination ◽  
High Concentrations ◽  
Glass Surfaces

The sole cell type (the amoebocyte) found in the coelomic fluid of the horseshoe crab, Limulus polyphemus can be stimulated to become motile by extravasation or trauma. Motility was studied using time-lapse microcinematography and direct microscopic examination of cells in tissue culture and in gill leaflets isolated from young animals. Phase-contrast and Nomarski differential-interference contrast optics were employed. Both in culture and in the gills, motile cells showed 2 interconvertible morphological types: the contracted cell, which was compact and rounded and had a relatively small area of contact with the substratum, and a flattened from with a larger area of contact. In both morphological types, motility involved the protrusion of hyaline pseudopods followed by flow of granular endoplasm forward in the pseudoplod. Cellular motility in vivo (in the gill leaflet) was morphologically identical to that displayed in tissue culture. In culture, motility was unaffected by the nature of the substratum: cells were indistinguishable on fluid (paraffin oil) or solid (glass) substrata or on hydrophobic (paraffin oil, siliconized glass) or hydrophilic (clean glass) surfaces. Cells migrated and spread on agar surfaces. Cell motility was unaffected by high concentrations (100 micrograms/ml) of the microtubule-depolymerizing agent colcemid and was abolished by cytochalasin B at 1 microgram/ml.

Haemocytology of the supraneural myeloid body in the sea lamprey during several phases of life cycle

1974 ◽  
Vol 52 (12) ◽  
pp. 1585-1589 ◽  
Author(s):  
J. C. George ◽  
F. W. H. Beamish
Keyword(s):  
Blood Cells ◽  
Petromyzon Marinus ◽  
Cell Types ◽  
Sea Lamprey ◽  
Histochemical Staining ◽  
Fat Cells ◽  
Cell Type ◽  
Adult Tissue ◽  
Spawning Run ◽  
Early Phases

The supraneural myeloid body of the sea lamprey (Petromyzon marinus) was studied in the feeding adult, late spawning run adult, and metamorphosing ammocoete. The fatty nature of the tissue was established by histochemical staining and electron microscopy. The presence of the fat cells and the actively differentiating blood cells evinced its similarity to the bone marrow in higher animals, thereby suggesting a phylogenetic affinity. In the late spawning run lampreys, the tissue was found to be almost empty of blood cells, leaving empty spaces within the stromal skeleton. In the feeding adult tissue, the various blood cell types differentiated from precursor cells have been identified. Megakaryoblasts possibly representing early phases of the cell type were observed only in the transforming (macrophthalmia stage) and adult lampreys. A marked active development of the tissue in the ammocoete was seen only at the fourth stage of the metamorphosing ammocoete immediately before macrophthalmia. At the macrophthalmia stage, the haematopoietic activity in the tissue increased substantially.

scholarly journals Differences in DNA methylation of white blood cell types at birth and in adulthood reflect postnatal immune maturation and influence accuracy of cell type prediction

2018 ◽  
Author(s):  
Meaghan J Jones ◽  
Louie Dinh ◽  
Hamid Reza Razzaghian ◽  
Olivia de Goede ◽  
Julia L MacIsaac ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Immune System ◽  
Blood Cell ◽  
Cord Blood ◽  
White Blood Cell ◽  
Blood Cells ◽  
Cell Types ◽  
Cell Type ◽  
Cell Type Specific ◽  
The Impact

AbstractBackgroundDNA methylation profiling of peripheral blood leukocytes has many research applications, and characterizing the changes in DNA methylation of specific white blood cell types between newborn and adult could add insight into the maturation of the immune system. As a consequence of developmental changes, DNA methylation profiles derived from adult white blood cells are poor references for prediction of cord blood cell types from DNA methylation data. We thus examined cell-type specific differences in DNA methylation in leukocyte subsets between cord and adult blood, and assessed the impact of these differences on prediction of cell types in cord blood.ResultsThough all cell types showed differences between cord and adult blood, some specific patterns stood out that reflected how the immune system changes after birth. In cord blood, lymphoid cells showed less variability than in adult, potentially demonstrating their naïve status. In fact, cord CD4 and CD8 T cells were so similar that genetic effects on DNA methylation were greater than cell type effects in our analysis, and CD8 T cell frequencies remained difficult to predict, even after optimizing the library used for cord blood composition estimation. Myeloid cells showed fewer changes between cord and adult and also less variability, with monocytes showing the fewest sites of DNA methylation change between cord and adult. Finally, including nucleated red blood cells in the reference library was necessary for accurate cell type predictions in cord blood.ConclusionChanges in DNA methylation with age were highly cell type specific, and those differences paralleled what is known about the maturation of the postnatal immune system.

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