Tunicate feeding filters

2003 ◽  
Vol 83 (5) ◽  
pp. 907-919 ◽  
Author(s):  
Q. Bone ◽  
C. Carré ◽  
P. Chang
Keyword(s):  
Protein Synthesis ◽  
Fine Structure ◽  
Gland Cell ◽  
Ecological Consequences ◽  
Gland Cells ◽  
Fine Mesh ◽  
Rectangular Mesh ◽  
Filter Mesh ◽  
Peptide Core

This review discusses the structure and operation of the fine mesh ‘mucous’ feeding filters of tunicates. The function of the endostyle in producing the feeding filter and the different ways in which the filter is deployed are also described.The fine structure of the filter includes new data, and the ultrastructural dimensions of the filter mesh and filament thickness are tabulated for the different tunicate groups. Histochemical data suggest that a peptide core is surrounded by a mucopolysaccharide sheath, and endostyle gland cell histochemistry and ultrastructure indicates protein synthesis. The construction of the filter by the endostyle was first considered in ascidians, and has been updated by observations on the simpler endostyle in salps, where there is evidence that secretions of gland cells pass to the bases of a fence of cilia, there to fuse and pass off the ciliary tips as fine filaments composing the filter net. Although all filters that have been examined when deployed have a rectangular mesh, reasons are given for supposing that when formed in the endostyle they have a square mesh in which both longitudinal and transverse filaments are of similar thickness and that the transverse filaments are stretched as the filter is deployed, so becoming thinner.Finally, some ecological consequences of the filter parameters in the different tunicate groups are considered.

Rate of protein synthesis in rat salivary gland cells after pilocarpine or feeding

1975 ◽  
Vol 164 (4) ◽  
pp. 447-456 ◽  
Author(s):  
A. H. Kuijper-Lenstra ◽  
M. F. Kramer ◽  
W. J. van Venrooij
Keyword(s):  
Protein Synthesis ◽  
Salivary Gland ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Rat Salivary Gland

Light microscopical and cytochemical study on the adhesive and epidermal gland cell secretions of the branchiobdellid Cambarincola fallax (Annelida: Clitellata)

1988 ◽  
Vol 66 (9) ◽  
pp. 2057-2064 ◽  
Author(s):  
S. R. Gelder ◽  
J. P. Rowe
Keyword(s):  
Basic Protein ◽  
Gland Cell ◽  
Attachment Site ◽  
Cell Types ◽  
The Body ◽  
Protein Component ◽  
Cell Type ◽  
Gland Cells ◽  
Adhesive Organs ◽  
Epidermal Gland

Eight types of gland cells are present in six different epidermal glands in the branchiobdellid Cambarincola fallax. The anterior and posterior adhesive organs are both composed of viscid and releaser adhesive gland cell types, and their secretions open onto the anterior attachment site on the ventral surface of the ventral peristomial lip and onto the posterior attachment disc, respectively. The secretion granules of the viscid gland cell type are composed of neutral mucosubstances with basic proteins containing arginine and (or) lysine; the releaser gland cell type contains basic proteinaceous granules with a tryptophan component. These adhesive glands are very similar to duo-gland adhesive organs described elsewhere. Use of the term "sucker" should be discontinued as there is no suctorial mechanism at the anterior attachment site and only circumstantial evidence of such action at the posterior disc. Two epidermal gland cell types occur together in groups of two to four cells at sites scattered over the body surface except in trunk segments 6 and 7. One of these epidermal gland cell types produces granular secretions formed of neutral mucosubstances with a basic protein component, and the other produces globular secretions composed of a carboxylated acid mucosubstance. Secretions from the peristomial gland cells open onto the dorsal and ventral lips. The posterolateral gland cells form three pairs: two pairs in segment 8 and one pair in segment 9. Both peristomial and posterolateral gland cells have granular secretions composed of neutral mucosubstances with a basic protein component. The two types of clitellar gland cells are arranged in groups of 7 to 13 cells with a granular secretion type predominating over one with globular secretions. The granular type consists of neutral mucosubstances with amyloid-like and strong basic protein components, and the globular type consists of a carboxylated acid mucosubstance with a nonbasic protein component.

Fine structure of the anterior adhesive apparatus (head organs) of Bravohollisia gussevi Lim, 1995 (Monogenea: Ancyrocephalidae)

Parasitology ◽  
2005 ◽  
Vol 132 (3) ◽  
pp. 427-438 ◽  
Author(s):  
W. L. WONG ◽  
G. P. BRENNAN ◽  
D. W. HALTON ◽  
L. H. S. LIM
Keyword(s):  
Electron Microscopy ◽  
Gland Cell ◽  
Light And Electron Microscopy ◽  
Dense Matrix ◽  
General Body ◽  
Gland Cells ◽  
Transmission Electron ◽  
Similar Band ◽  
Electron Dense Matrix ◽  
Dense Vesicles

A study of the anterior adhesive apparatus (head organs) of Bravohollisia gussevi Lim, 1995 was carried out using light and electron microscopy. The anterior adhesive apparatus or head organs in B. gussevi comprise 6 circular openings or apertures in the antero-lateral region, associated pits lined with specialized microvillous tegument that differ from the general body tegument, a bundle of ducts, and uninucleate gland cells located lateral to the pharynx. The uninucleate glands of the anterior adhesive apparatus (head organs) comprise 2 types of cells, one kind of cell producing rod-like bodies (S1) and the other oval bodies (S2). The S1 bodies are filled with numerous, less electron-dense vesicles in an electron-dense matrix, while S2 bodies have no vesicles but contain a more homogeneous electron-dense matrix. Interlinking band-like structures were observed between S1 bodies. Similar band-like structures were found between S2 bodies. The formation of S1 bodies was followed by transmission electron microscopy. However, the formation of S2 bodies was unclear and could not be resolved. Uniciliated structures were also observed around the openings of the anterior adhesive apparatus. Each uniciliated structure is usually associated with an opening of a gland cell producing granular, electron-dense, secretory bodies, which differ from the secretions produced by the lateral gland cells of the anterior adhesive apparatus.

scholarly journals Small Molecules Facilitate Single Factor-Mediated Sweat Gland Cell Reprogramming

2021 ◽  
Author(s):  
Shuaifei Ji ◽  
Yan Li ◽  
Laixian Zhou ◽  
Jiangbing Xiang ◽  
Huating Chen ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Sweat Gland ◽  
Gland Cell ◽  
Dermal Fibroblasts ◽  
Cell Phenotype ◽  
Skin Defect ◽  
Single Factor ◽  
Gland Cells ◽  
Functional Features

Abstract Background: Large skin defect caused severe disruption to the overall skin structure and irreversible damage of sweat gland (SG), resulting in destroy of physiological function of the skin. Reprogramming fibroblasts into sweat gland lineages may provide a promising strategy to obtain the desirable cell types for functional repair and regeneration of damaged skin. Methods: A direct reprogramming strategy of single factor ectodermal dysplasia antigen (EDA) in combination with small molecule cocktails promoting cell-fate conversion to regenerate SG cells from human dermal fibroblasts (HDFs) was developed. Quantitative PCR (qPCR), flow cytometry, calcium activity analysis, immunocytochemical analyses and starch-iodine sweat tests were used to characterize the phenotype, gene expression and function features of the induced sweat gland cells (iSGCs). Results: EDA overexpression drove HDFs toward SG lineages, and HDFs transfected with EDA acquired sweat gland cell phenotype in sweat gland conditional medium (SGM). Small-molecule cocktails favoring SG lineages greatly accelerated the SG fate program in SGM-treated HDF-EDA cells and further induced the regeneration of iSGCs. The HDFs-derived iSGCs exhibited similar phenotypical and functional features of native sweat gland cells. Eventually, in vivo transplantation experiment confirmed that iSGCs had the ability to regenerate SG structurally and functionally.Conclusion: We developed a SG reprogramming strategy to generate functional iSGCs from HDFs by using single factor EDA in combination with small molecules. The generation of iSGCs has important implications for in situ skin regeneration with restoration of sweat glands in the future.

Effect of methacholine on Na+ pump activity and ion content of dispersed avian salt gland cells

1981 ◽  
Vol 241 (1) ◽  
pp. R77-R86
Author(s):  
S. R. Hootman ◽  
S. A. Ernst
Keyword(s):  
Binding Sites ◽  
Gland Cell ◽  
Salt Gland ◽  
Ion Content ◽  
Ouabain Binding ◽  
Gland Cells ◽  
Na Pump ◽  
Pump Activity ◽  
Number Of Binding Sites ◽  
Dissociated Cells

The effects of the cholinergic agonist methacholine chloride (MCh) on cellular ion content and Na+ pump activity of dissociated duck salt gland cells were studied. Dispersed salt gland cells regulate intracellular ion levels in a ouabain-sensitive manner. MCh (0.5 mM) caused no detectable change in cell Na+ levels over the first 10 min of exposure of cells to the agonist but elicited decreases of 23 and 13%, respectively, in intracellular Cl- and K+ content. The rate of turnover of salt gland cell plasmalemmal Na+ pumps, as measured by [3H]ouabain binding to the dissociated cells, was markedly stimulated by 0.5 mM MCh, although the total number of binding sites at equilibrium remained unchanged. Replacement of medium Na+ with choline abolished the MCh-stimulated increase in ouabain binding but had no effect on the rate of glycoside binding in the absence of the agonist. Substitution of Cl- in the medium by NO3-, SO42-, or benzene sulfonate- reduced the stimulated component of Na+ pump turnover by 85-90%. Addition of 1 mM furosemide to the medium abolished the increase in ouabain binding and ouabain-sensitive oxygen consumption observed after exposure of salt gland cells to MCh. These data are consistent with the hypothesis that cholinergic stimulation of salt gland cells triggers a Cl--dependent uptake of Na+, which elicits a compensatory increase in Na+ pump turnover. In addition, the decrease in cellular Cl- content caused by MCh suggests that the agonist either directly or indirectly mediates an efflux of Cl- from the cells.

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