scholarly journals Release and spread of Wingless is required to pattern the proximo-distal axis of Drosophila renal tubules

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Robin Beaven ◽  
Barry Denholm
Keyword(s):  
Proximal Tubule ◽  
Long Range ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Renal Tubules ◽  
Animal Development ◽  
Signalling Molecules ◽  
Developmental Contexts ◽  
Epithelial Tubes

Wingless/Wnts are signalling molecules, traditionally considered to pattern tissues as long-range morphogens. However, more recently the spread of Wingless was shown to be dispensable in diverse developmental contexts in Drosophila and vertebrates. Here we demonstrate that release and spread of Wingless is required to pattern the proximo-distal (P-D) axis of Drosophila Malpighian tubules. Wingless signalling, emanating from the midgut, directly activates odd skipped expression several cells distant in the proximal tubule. Replacing Wingless with a membrane-tethered version that is unable to diffuse from the Wingless producing cells results in aberrant patterning of the Malpighian tubule P-D axis and development of short, deformed ureters. This work directly demonstrates a patterning role for a released Wingless signal. As well as extending our understanding about the functional modes by which Wnts shape animal development, we anticipate this mechanism to be relevant to patterning epithelial tubes in other organs, such as the vertebrate kidney.

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.

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.

Anti-diuresis in the blood-feeding insect Rhodnius prolixus Stål: the peptide CAP2b and cyclic GMP inhibit Malpighian tubule fluid secretion.

1997 ◽  
Vol 200 (17) ◽  
pp. 2363-2367 ◽  
Author(s):  
M C Quinlan ◽  
N J Tublitz ◽  
M J O'Donnell
Keyword(s):  
Cyclic Gmp ◽  
Physiological Role ◽  
Malpighian Tubule ◽  
Fluid Secretion ◽  
Blood Feeding ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Tubule Fluid ◽  
Secretion Rates

Rhodnius prolixus eliminates NaCl-rich urine at high rates following its infrequent but massive blood meals. This diuresis involves stimulation of Malpighian tubule fluid secretion by diuretic hormones released in response to distention of the abdomen during feeding. The precipitous decline in urine flow that occurs several hours after feeding has been thought until now to result from a decline in diuretic hormone release. We suggest here that insect cardioacceleratory peptide 2b (CAP2b) and cyclic GMP are part of a novel mechanism of anti-diuresis. Secretion rates of 5-hydroxytryptamine-stimulated Malpighian tubules are reduced by low doses of CAP2b or cyclic GMP. Maximal secretion rates are restored by exposing tubules to 1 mmol l-1 cyclic AMP. Levels of cyclic GMP in isolated tubules increase in response to CAP2b, consistent with a role for cyclic GMP as an intracellular second messenger. Levels of cyclic GMP in tubules also increase as urine output rates decline in vivo, suggesting a physiological role for this nucleotide in the termination of diuresis.

The permeability properties of septate junctions in Malpighian tubules of Rhodnius

1987 ◽  
Vol 88 (2) ◽  
pp. 251-265 ◽  
Author(s):  
H.B. Skaer ◽  
S.H. Maddrell ◽  
J.B. Harrison
Keyword(s):  
Structural Characteristics ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Septate Junctions ◽  
Blood Sucking ◽  
Effects Of Ph ◽  
Intercellular Clefts ◽  
Luminal Flow ◽  
Tubule Cells ◽  
Positively Charged

This paper describes the structural characteristics and permeability properties of the smooth septate junctions between the upper Malpighian tubule cells of a blood-sucking bug, Rhodnius prolixus. The permeability of the paracellular route was tested only for solutes that could be demonstrated not to cross the epithelium via the cellular route. The intercellular clefts were readily permeated by sucrose, inulin and polyethylene glycol (PEG), showing a higher permeability to molecules of smaller radius (PEG versus sucrose). Negatively charged molecules permeated the clefts more readily than positively charged ones. The effects of pH, urea and luminal flow rate on permeability were studied. The results are discussed in relation to the physiological tightness of the Malpighian tubules to certain solutes and to its function as an excretory epithelium.

scholarly journals Active transport of brilliant blue FCF across the Drosophila midgut and Malpighian tubule epithelia

2019 ◽  
Author(s):  
Dawson B.H. Livingston ◽  
Hirva Patel ◽  
Andrew Donini ◽  
Heath A. MacMillan
Keyword(s):  
Traumatic Injury ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Brilliant Blue ◽  
Barrier Dysfunction ◽  
Concentration Gradients ◽  
Barrier Disruption ◽  
Brilliant Blue Fcf ◽  
Summary Statement

AbstractUnder conditions of stress, many animals suffer from epithelial barrier disruption that can cause molecules to leak down their concentration gradients, potentially causing a loss of organismal homeostasis, further injury or death. Drosophila is a common insect model, used to study barrier disruption related to aging, traumatic injury, or environmental stress. Net leak of a non-toxic dye (Brilliant blue FCF) from the gut lumen to the hemolymph is often used to identify barrier failure under these conditions, but Drosophila are capable of actively transporting structurally-similar compounds. Here, we examined whether cold stress (like other stresses) causes Brilliant blue FCF (BB-FCF) to appear in the hemolymph of flies fed the dye, and if so whether Drosophila are capable of clearing this dye from their body following chilling. Using in situ midgut leak and transport assays as well as Ramsay assays of Malpighian tubule transport, we tested whether these ionoregulatory epithelia can actively transport BB-FCF. In doing so, we found that the Drosophila midgut and Malpighian tubules can mobilize BB-FCF via an active transcellular pathway, suggesting that elevated concentrations of the dye in the hemolymph may occur from increased paracellular permeability, reduced transcellular clearance, or both.Summary StatementDrosophila are able to actively secrete Brilliant blue FCF, a commonly used marker of barrier dysfunction

Amino-Acid Metabolism in Locust Tissues

1957 ◽  
Vol 34 (2) ◽  
pp. 276-289
Author(s):  
B. A. KILBY ◽  
ELISABETH NEVILLE
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Schistocerca Gregaria ◽  
Fat Body ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Mitochondrial Fractions

1. Homogenates of fat-body of Schistocerca gregaria Forsk. were shown to catalyse transamination reactions between α-ketoglutarate and numerous α-amino acids. The aspartate/glutamate and alanine/glutamate transaminases were the most active. They were present in both the ‘soluble’ and the mitochondrial fractions of fat-body cells and also in Malpighian tubules and mid-gut wall. The other transaminases in the fat-body were confined to the mitochondrial fraction. 2. Fat-body, Malpighian tubule and mid-gut wall homogenates were able to convert glutamic acid into glutamine, a compound which could also act as an amino-group donor in some transamination reactions. 3. A glutamate-cytochrome c reductase system which involved diphosphopyridine nucleotide was present in fat-body. 4. Fat-body contained an active arginase, but urease could not be detected. A D-amino-acid oxidase was present, together with a less active L-amino-acid oxidase. 5. In general, it appears that amino-acid metabolism in the locust resembles that in higher animals.

The Reduced Glucose Permeability of the Isolated Malpighian Tubules of the Blowfly Calliphora Vomitoria

1975 ◽  
Vol 62 (2) ◽  
pp. 327-340
Author(s):  
G. KNOWLES
Keyword(s):  
Molecular Weight ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Glucose Reabsorption ◽  
Glucose Excretion ◽  
Tubule Wall

The excretion of several sugars by the isolated Malpighian tubules of Calliphora vomitoria has been investigated. The isolated tubules do not excrete glucose or trehalose at rates similar to those of sugars of the same molecular weight. Trehalose can be hydrolysed to glucose as it traverses the tubule wall. It is proposed that glucose can be reabsorbed by the tubule. Evidence is presented to suggest that glucose reabsorption can be saturated. Phloridzin was found to increase the rate of glucose excretion by the isolated Malpighian tubule.

Expression of bcl-2 and bax in regenerating rat renal tubules following ischemic injury

1997 ◽  
Vol 272 (5) ◽  
pp. F640-F647 ◽  
Author(s):  
D. P. Basile ◽  
H. Liapis ◽  
M. R. Hammerman
Keyword(s):  
Proximal Tubule ◽  
Ischemic Injury ◽  
Fold Increase ◽  
Renal Tubules ◽  
Proximal Tubule Cells ◽  
Protein Levels ◽  
Bax Protein ◽  
Adult Kidney ◽  
Predictable Pattern

To define potential roles for bcl-2 and bax in adult kidney as regulators of regeneration, their expressions were characterized postischemic injury. A 2.1-fold increase in levels of renal bcl-2 mRNA occurred within 24 h of injury relative to levels in kidney of sham-operated control rats. The levels of bcl-2 mRNA remained elevated for 3 days but returned to baseline by day 5 postischemia. In situ hybridization of kidneys from sham-operated rats demonstrated faint expression of bcl-2 mRNA localized diffusely throughout the nephron. After renal injury, the expression of bcl-2 mRNA was markedly enhanced in regenerating proximal tubule cells relining the basement membrane. Immunohistochemistry showed a similar localization for bcl-2 protein. Levels of bax mRNA in kidney were elevated beginning at 24 h postischemia and remained elevated for 7 days postinjury. Bax mRNA and bax protein were colocalized to regenerating proximal tubules postischemia and were prominently expressed in papillary proliferations. We conclude that the expressions of bcl-2 and bax in kidney are enhanced in a predictable pattern following acute ischemic injury. Our findings suggest that these regulators of apoptosis play key roles in the process of repair of the damaged proximal tubule postischemia.

Voltage clamping single cells in intact Malpighian tubules of mosquitoes

2000 ◽  
Vol 279 (4) ◽  
pp. F747-F754 ◽  
Author(s):  
R. Masia ◽  
D. Aneshansley ◽  
W. Nagel ◽  
R. J. Nachman ◽  
K. W. Beyenbach
Keyword(s):  
Apical Membrane ◽  
Single Cells ◽  
Basolateral Membrane ◽  
Malpighian Tubule ◽  
Input Resistance ◽  
Membrane Resistance ◽  
Malpighian Tubules ◽  
Shunt Resistance ◽  
Transport Pathways ◽  
Principal Cells

Principal cells of the Malpighian tubule of the yellow fever mosquito were studied with the methods of two-electrode voltage clamp (TEVC). Intracellular voltage ( V pc) was −86.7 mV, and input resistance ( R pc) was 388.5 kΩ ( n = 49 cells). In six cells, Ba2+ (15 mM) had negligible effects on V pc, but it increased R pc from 325.3 to 684.5 kΩ ( P< 0.001). In the presence of Ba2+, leucokinin-VIII (1 μM) increased V pc to −101.8 mV ( P < 0.001) and reduced R pc to 340.2 kΩ ( P < 0.002). Circuit analysis yields the following: basolateral membrane resistance, 652.0 kΩ; apical membrane resistance, 340.2 kΩ; shunt resistance ( R sh), 344.3 kΩ; transcellular resistance, 992.2 kΩ. The fractional resistance of the apical membrane (0.35) and the ratio of transcellular resistance and R sh (3.53) agree closely with values obtained by cable analysis in isolated perfused tubules and confirm the usefulness of TEVC methods in single principal cells of the intact Malpighian tubule. Dinitrophenol (0.1 mM) reversibly depolarized V pc from −94.3 to −10.7 mV ( P< 0.001) and reversibly increased R pc from 412 to 2,879 kΩ ( P < 0.001), effects that were duplicated by cyanide (0.3 mM). Significant effects of metabolic inhibition on voltage and resistance suggest a role of ATP in electrogenesis and the maintenance of conductive transport pathways.

Cytogenetic analysis of Malpighian tubule polytene chromosomes of Culex pipiens (Diptera: Culicidae)

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 751-755 ◽  
Author(s):  
Anna Zambetaki ◽  
Nicole Pasteur ◽  
Penelope Mavragani-Tsipidou
Keyword(s):  
Culex Pipiens ◽  
Polytene Chromosomes ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Molecular Cytogenetic ◽  
Routine Basis ◽  
Weak Points ◽  
Chromosome Maps ◽  
Global Vector ◽  
Polytene Nuclei

A simple technique is described for obtaining well-spread and readable Malpighian tubule polytene nuclei of Culex pipiens on a routine basis. Detailed polytene chromosome maps are presented with a description of the most prominent landmarks of each chromosome, the regions with asynapsis and the most frequent weak points identified in the polytene arms. Usable Malpighian tubule polytene chromosomes should facilitate molecular cytogenetic, genetic, and potentially biosystematic studies on this medically important global vector of viral inducing encephalitis.Key words: Culex pipiens, polytene chromosomes, Malpighian tubules, banding pattern, photomap.

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