A study of the Malpighian tubules of the plecopteran nymph Paragnetina media (Walker) (Plecoptera: Perlidae) by light, scanning electron, and transmission electron microscopy

1994 ◽  
Vol 72 (9) ◽  
pp. 1566-1575 ◽  
Author(s):  
N. N. Kapoor
Keyword(s):  
Malpighian Tubule ◽  
Stellate Cells ◽  
Basal Membrane ◽  
Cell Types ◽  
Distal Segment ◽  
Malpighian Tubules ◽  
Primary Cells ◽  
Transmission Electron ◽  
Total Cell Population ◽  
Paragnetina Media

The present study concerns the structural details of the Malpighian tubules in the nymph of the stonefly Paragnetina media. There is no external segmentation except for a distal short hyaline segment. The tubules are composed of two cell types: primary and stellate. Primary cells in the proximal and middle portions of the tubule have short infoldings of the basal membrane and the cytosol is packed with laminate spheres. Cells of the distal segment possess long and tightly packed membrane folds but are devoid of laminate spheres. The stellate cells are sparsely distributed in the middle region and make up 12% of the total cell population in the Malpighian tubule; they lack laminate spheres. Long processes of the stellate cells extend between adjacent primary cells to the luminal and outer surfaces of the tubule.

Fine Structure of the Malpighian Tubules of the Mosquito, Culex pipiens

1971 ◽  
Vol 29 ◽  
pp. 402-403
Author(s):  
Brendan Clifford
Keyword(s):  
Fine Structure ◽  
Culex Pipiens ◽  
Stellate Cell ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Instar Larva ◽  
Malpighian Tubules ◽  
Calliphora Erythrocephala ◽  
Distinct Cell ◽  
Basal Plasma

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.

scholarly journals A cell atlas of the fly kidney

2021 ◽  
Author(s):  
Jun Xu ◽  
Yifang Liu ◽  
Hongjie Li ◽  
Alexander J. Tarashansky ◽  
Colin H. Kalicki ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Kidney Cell ◽  
Single Cells ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Malpighian Tubules ◽  
Disease Models ◽  
Marker Genes ◽  
Waste Products ◽  
Renal Stem Cells

Like humans, insects rely on precise regulation of their internal environments to survive. The insect renal system consists of Malpighian tubules and nephrocytes that share similarities to the mammalian kidney. Studies of the Drosophila Malpighian tubules and nephrocytes have provided many insights into our understanding of the excretion of waste products, stem cell regeneration, protein reabsorption, and as human kidney disease models. Here, we analyzed single-nucleus RNA sequencing (snRNA-seq) data sets to characterize the cell types of the adult fly kidney. We identified 11 distinct clusters representing renal stem cells (RSCs), stellate cells (SCs), regionally specific principal cells (PCs), garland nephrocyte cells (GCs) and pericardial nephrocytes (PNs). Analyses of these clusters revealed many new interesting features. For example, we found a new, previously unrecognized cell cluster: lower segment PCs that express Esyt2. In addition, we find that the SC marker genes RhoGEF64c, Frq2, Prip and CG10939 regulate their unusual cell shape. Further, we identified transcription factors specific to each cluster and built a network of signaling pathways that are potentially involved in mediating cell-cell communication between Malpighian tubule cell types. Finally, cross-species analysis allowed us to match the fly kidney cell types to mouse kidney cell types and planarian protonephridia - knowledge that will help the generation of kidney disease models. To visualize this dataset, we provide a web-based resource for gene expression in single cells (https://www.flyrnai.org/scRNA/kidney/). Altogether, our study provides a comprehensive resource for addressing gene function in the fly kidney and future disease studies.

Localization of endogenous and recombinant Na+-driven anion exchanger protein NDAE1 fromDrosophila melanogaster

2001 ◽  
Vol 281 (2) ◽  
pp. C449-C463 ◽  
Author(s):  
Christopher M. Sciortino ◽  
Lamara D. Shrode ◽  
Bonnie R. Fletcher ◽  
Peter J. Harte ◽  
Michael F. Romero
Keyword(s):  
Xenopus Oocytes ◽  
Alimentary Tract ◽  
Regulatory Protein ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Malpighian Tubules ◽  
Developmental Expression ◽  
Α Subunit ◽  
Vertebrate Cell ◽  
Exchange Activity

Na+-dependent Cl−/HCO[Formula: see text]exchange activity helps maintain intracellular pH (pHi) homeostasis in many invertebrate and vertebrate cell types. Our laboratory cloned and characterized a Na+-dependent Cl−/HCO[Formula: see text] exchanger (NDAE1) from Drosophila melanogaster (Romero MF, Henry D, Nelson S, Harte PJ, and Sciortino CM. J Biol Chem 275: 24552–24559, 2000). In the present study we used immunohistochemical and Western blot techniques to characterize the developmental expression, subcellular localization, and tissue distribution of NDAE1 protein in D. melanogaster. We have shown that a polyclonal antibody raised against the NH2terminus of NDAE1 (αCWR57) recognizes NDAE1 electrophysiologically characterized in Xenopus oocytes. Moreover, our results begin to delineate the NDAE1 topology, i.e., both the NH2and COOH termini are intracellular. NDAE1 is expressed throughout Drosophila development in the central and peripheral nervous systems, sensilla, and the alimentary tract (Malpighian tubules, gut, and salivary glands). Coimmunolabeling of larval tissues with NDAE1 antibody and a monoclonal antibody to the Na+-K+-ATPase α-subunit revealed that the majority of NDAE1 is located at the basolateral membranes of Malpighian tubule cells. These results suggest that NDAE1 may be a key pHi regulatory protein and may contribute to basolateral ion transport in epithelia and nervous system of Drosophila.

Transport of the cationic fluorochrome rhodamine 123 in an insect's Malpighian tubule: indications of a reabsorptive function of the secondary cell type

1992 ◽  
Vol 101 (2) ◽  
pp. 349-361
Author(s):  
W. Meulemans ◽  
A. De Loof
Keyword(s):  
Lucifer Yellow ◽  
Malpighian Tubule ◽  
Inhibitory Effect ◽  
Malpighian Tubules ◽  
Rhodamine 123 ◽  
Primary Cells ◽  
Short Period ◽  
Selective Accumulation

The pathway of rhodamine 123 was examined after injection into Sarcophaga flies and after in vitro labeling of the Malpighian tubules. After in vitro labeling the primary cells only retained this potential-sensitive dye for a short period while all secondary cells accumulated the dye from the tubule lumen. In vivo the secondary cells also accumulated rhodamine 123 from the lumen, but the primary cells in the distal parts of all four tubules retained the dye for prolonged periods. This was most pronounced in the distal part of the anterior Malpighian tubules, where rhodamine 123 was eventually precipitated on the luminal concretions. Rhodamine 123 initially accumulated in the secondary cell mitochondria and eventually in intensely fluorescing vesicles, probably lysosomes. No evidence for endocytotic processes from the lumen was found using Lucifer Yellow CH, fluorescent dextrans and fluorescent albumin. Prior incubation with the ionophores valinomycin, nigericin, CCCP (all 1 micrograms/ml), dinitrophenol (1 mM) and NaN3 (10(−2) M) inhibited the selective accumulation of rhodamine 123 to a large extent while monensin (1–5 micrograms/ml) showed little inhibitory effect. Furthermore, only cationic and no anionic or neutral dyes were accumulated by the secondary cells. In the fleshfly Calliphora and the fruitfly Drosophila, the dye rhodamine 123 also selectively accumulated in the secondary cells, as well in vitro as in vivo.

A Malpighian Tubule Lime Gland in an Insect Inhabiting Alkaline Salt Lakes

1989 ◽  
Vol 145 (1) ◽  
pp. 63-78 ◽  
Author(s):  
DAVID B. HERBST ◽  
TIMOTHY J. BRADLEY
Keyword(s):  
Malpighian Tubule ◽  
Cell Types ◽  
Chemical Precipitation ◽  
Malpighian Tubules ◽  
Salt Lakes ◽  
Alkaline Salt ◽  
X Ray ◽  
Posterior Pair ◽  
High Concentrations ◽  
Scanning Electron

The alkali fly, Ephydra hians Say, inhabits alkaline salt lakes which can contain concentrations of dissolved carbonate and bicarbonate as high as 500 mmol l−1. Larvae of the alkali fly possess two pairs of Malpighian tubules. The posterior pair has a morphology similar to that of the tubules of most other insects, but the anterior pair is modified into an enlarged gland containing white microsphere concretions. We describe the ultrastructure of all cell types in both pairs of tubules. Using scanning electron microscope (SEM) X-ray microanalysis and chemical CO2 quantification, we demonstrate that the concretions in the lime glands are composed of nearly pure calcium carbonate. Isolated preparations of lime gland tubules accumulate 45Ca significantly more rapidly than do normal tubules. Although similar to the rime concretions found in the Malpighian tubules of other Diptera, the lime glands of this insect may function to regulate the high concentrations of carbonate and bicarbonate encountered in their aquatic environment. It is proposed that the mechanism of this regulation may be chemical precipitation of carbonate/bicarbonate with calcium in the lumen of these specialized lime gland tubules.

scholarly journals A SLC4-like anion exchanger from renal tubules of the mosquito (Aedes aegypti): evidence for a novel role of stellate cells in diuretic fluid secretion

2010 ◽  
Vol 298 (3) ◽  
pp. R642-R660 ◽  
Author(s):  
Peter M. Piermarini ◽  
Laura F. Grogan ◽  
Kenneth Lau ◽  
Li Wang ◽  
Klaus W. Beyenbach
Keyword(s):  
Aedes Aegypti ◽  
Anion Exchanger ◽  
Xenopus Oocytes ◽  
Malpighian Tubule ◽  
Stellate Cells ◽  
Fluid Secretion ◽  
Malpighian Tubules ◽  
Renal Tubules ◽  
Basal Region ◽  
Principal Cells

Transepithelial fluid secretion across the renal (Malpighian) tubule epithelium of the mosquito ( Aedes aegypti ) is energized by the vacuolar-type (V-type) H+-ATPase and not the Na+-K+-ATPase. Located at the apical membrane of principal cells, the V-type H+-ATPase translocates protons from the cytoplasm to the tubule lumen. Secreted protons are likely to derive from metabolic H2CO3, which raises questions about the handling of HCO3−by principal cells. Accordingly, we tested the hypothesis that a Cl/HCO3anion exchanger (AE) related to the solute-linked carrier 4 (SLC4) superfamily mediates the extrusion of HCO3−across the basal membrane of principal cells. We began by cloning from Aedes Malpighian tubules a full-length cDNA encoding an SLC4-like AE, termed AeAE. When expressed heterologously in Xenopus oocytes, AeAE is both N- and O-glycosylated and mediates Na+-independent intracellular pH changes that are sensitive to extracellular Cl−concentration and to DIDS. In Aedes Malpighian tubules, AeAE is expressed as two distinct forms: one is O-glycosylated, and the other is N-glycosylated. Significantly, AeAE immunoreactivity localizes to the basal regions of stellate cells but not principal cells. Concentrations of DIDS that inhibit AeAE activity in Xenopus oocytes have no effects on the unstimulated rates of fluid secretion mediated by Malpighian tubules as measured by the Ramsay assay. However, in Malpighian tubules stimulated with kinin or calcitonin-like diuretic peptides, DIDS reduces the diuretic rates of fluid secretion to basal levels. In conclusion, Aedes Malpighian tubules express AeAE in the basal region of stellate cells, where this transporter may participate in producing diuretic rates of transepithelial fluid secretion.

scholarly journals When two cells are better than one: specialized stellate cells provide a privileged route for uniquely rapid water flux in Drosophila renal tubule

2019 ◽  
Author(s):  
Pablo Cabrero ◽  
Selim Terhzaz ◽  
Anthony J. Dornan ◽  
Saurav Ghimire ◽  
Heather L. Holmes ◽  
...  
Keyword(s):  
Water Permeability ◽  
Plasma Membranes ◽  
Water Flux ◽  
Malpighian Tubule ◽  
Stellate Cells ◽  
Fluid Secretion ◽  
Malpighian Tubules ◽  
Principal Cells ◽  
Very High

AbstractInsects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 members of the Major Intrinsic Protein family are expressed at very high level in the fly renal tissue; the aquaporins Drip and Prip, and the aquaglyceroporins Eglp2 and Eglp4. As predicted from their structure and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes impacts tubule performance resulting in impaired hormone-induced fluid secretion. The Drosophila tubule has two main secretory cell types: active cation-transporting principal cells with the aquaglyceroporins localize to opposite plasma membranes and small stellate cells, the site of the chloride shunt conductance, with these aquaporins localising to opposite plasma membranes. This suggests a model in which cations are pumped by the principal cells, causing chloride to follow through the stellate cells in order to balance the charge. As a consequence, osmotically obliged water follows through the stellate cells. Consistent with this model, fluorescently labelled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects.Significance statementThe tiny insect renal (Malpighian) tubule can transport fluid at unparalleled speed, suggesting unique specialisations. Here we show that strategic allocation of Major Intrinsic Proteins (MIPs) to specific cells within the polarized tubule allow the separation of metabolically intense active cation transport from chloride and water conductance. This body plan is general to at least many higher insects, providing a clue to the unique success of the class Insecta.

Characterization of transepithelial potential oscillations in theDrosophilaMalpighian tubule

2001 ◽  
Vol 204 (17) ◽  
pp. 3075-3084 ◽  
Author(s):  
Edward M. Blumenthal
Keyword(s):  
Calcium Release ◽  
Chloride Concentration ◽  
Malpighian Tubule ◽  
Stellate Cells ◽  
Cell Types ◽  
Chloride Conductance ◽  
Potential Oscillations ◽  
Inositol Trisphosphate Receptor ◽  
Transepithelial Potential ◽  
Trisphosphate Receptor

SUMMARYThe Malpighian tubule of Drosophila melanogaster is a useful model system for studying the regulation of epithelial ion transport. In acutely isolated tubules, the transepithelial potential (TEP) undergoes large oscillations in amplitude with a period of approximately 30s. The TEP oscillations are diminished by reductions in the peritubular chloride concentration in a manner consistent with their being caused by fluctuations in chloride conductance. The oscillations are eliminated by pretreating tubules with the calcium chelator BAPTA-AM, although removal of peritubular calcium has no effect, suggesting that the oscillations are a result of either the release of calcium from intracellular stores or the entry of calcium from the tubule lumen. Transcripts encoding two calcium-release channels, the ryanodine receptor and the inositol trisphosphate receptor, are detectable in the tubule by reverse transcription–polymerase chain reaction. To identify the cell type responsible for the oscillations, tubules were treated with diuretic hormones known to alter calcium levels in each of the two cell types. Leucokinin-IV, which increases calcium levels in the stellate cells, suppressed the oscillations, whereas cardioacceleratory peptide 2b (CAP2b), which increases calcium levels in the principal cells, had no effect. These data are consistent with a model in which rhythmic changes in transepithelial chloride conductance, regulated by intracellular calcium levels in the stellate cells, cause the TEP oscillations.

scholarly journals CELLULAR SPECIALIZATION IN THE EXCRETORY EPITHELIA OF AN INSECT, Macrosteles fascifrons STÅL (HOMOPTERA)

1960 ◽  
Vol 8 (1) ◽  
pp. 103-133 ◽  
Author(s):  
David S. Smith ◽  
Virginia C. Littau
Keyword(s):  
Malpighian Tubule ◽  
Cell Types ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Malpighian Tubules ◽  
Apical Surface ◽  
Electron Microscopic ◽  
Distinct Cell ◽  
Protein Components ◽  
Cellular Specialization

An electron microscopic investigation of the Malpighian tubules of a leaf hopper, Macrosteles fascifrons, shows that these organs comprise three quite distinct cell types, and the structure of these and of the mid- and hindgut epithelial cells is described. In particular, a comparison is made between the organization of the basal and apical surfaces of cells in the Malpighian tubule and in the vertebrate kidney, and it is suggested that similarities between these excretory epithelia reflect functional parallels between them. While the midgut and one region of the Malpighian tubule bear a typical microvillar brush border, elsewhere in the tubule and in the hindgut the apical surface bears cytoplasmic leaflets or lamellae. The sole solid excretory material of these insects consists of the brochosomes, secreted by cells of one region of the Malpighian tubule. The structure, geometry, and development of these unusual bodies, apparently formed within specialized Golgi regions, has been investigated, and histochemical tests indicate that they contain lipid and protein components.

scholarly journals Specialized stellate cells offer a privileged route for rapid water flux in Drosophila renal tubule

2020 ◽  
Vol 117 (3) ◽  
pp. 1779-1787 ◽  
Author(s):  
Pablo Cabrero ◽  
Selim Terhzaz ◽  
Anthony J. Dornan ◽  
Saurav Ghimire ◽  
Heather L. Holmes ◽  
...  
Keyword(s):  
Water Permeability ◽  
Plasma Membranes ◽  
Water Flux ◽  
Stellate Cells ◽  
Fluid Secretion ◽  
Cell Types ◽  
Renal Tissue ◽  
Malpighian Tubules ◽  
Very High

Insects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 genes of the major intrinsic protein family are expressed at a very high level in the fly renal tissue: the aquaporins (AQPs) Drip and Prip and the aquaglyceroporins Eglp2 and Eglp4. As predicted from their structure, and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip, and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes result in impaired hormone-induced fluid secretion. The Drosophila tubule has 2 main secretory cell types: active cation-transporting principal cells, wherein the aquaglyceroporins localize to opposite plasma membranes, and small stellate cells, the site of the chloride shunt conductance, with these AQPs localizing to opposite plasma membranes. This suggests a model in which osmotically obliged water flows through the stellate cells. Consistent with this model, fluorescently labeled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects in regulating their internal environments.

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