scholarly journals THE ROUTE OF ENTRY AND LOCALIZATION OF BLOOD PROTEINS IN THE OOCYTES OF SATURNIID MOTHS

1961 ◽  
Vol 9 (4) ◽  
pp. 747-759 ◽  
Author(s):  
William H. Telfer
Keyword(s):  
Brush Border ◽  
Cell Layer ◽  
Follicle Cell ◽  
Blood Proteins ◽  
Intercellular Spaces ◽  
Protein Uptake ◽  
Freeze Dried ◽  
Yellow Pigments

The oocytes of saturniid moths take up proteins selectively from the blood. The distribution of blood proteins in the ovary during protein uptake was investigated by staining 2 µ sections of freeze-dried ovaries with fluorescein-labeled antibodies. The results indicate that blood proteins occur primarily in the intercellular spaces of the follicle cell layer, in association with a brush border at the surface of the oocyte, and within the oocyte in the yolk spheres. That proteins derived from the blood are associated with the yolk spheres was confirmed by isolating these bodies and showing that lysis, which can be induced by any of a number of mechanical means, causes them to release immunologically defined proteins known to be derived from the blood. That the level of blood proteins in the cytoplasm is low relatively to that in the yolk spheres was confirmed by the observation that the yellow pigments associated with several blood proteins, although conspicuous in the yolk spheres, are not visible in the translucent layer of centrifuged oocytes. From these and previous physiological observations, it is proposed that blood proteins reach the surface of the oocyte by an intercellular route, that they combine with some component of the brush border, and that they are transformed into yolk spheres by a process akin to pinocytosis.

Trypan blue inhibition of yolk deposition—a clue to follicle cell function in the cecropia moth

Development ◽  
1970 ◽  
Vol 23 (1) ◽  
pp. 35-52
Author(s):  
Lucy M. Anderson ◽  
William H. Telfer
Keyword(s):  
Trypan Blue ◽  
Cell Function ◽  
Follicle Cell ◽  
Maternal Blood ◽  
Ovarian Follicles ◽  
Follicular Epithelium ◽  
Blood Proteins ◽  
Intercellular Spaces ◽  
Insect Eggs

The yolk of insect eggs consists largely of proteins derived pinocytotically from the maternal blood (Telfer, 1965). Vitellogenic oocytes can also sequester the acidic colloid trypan blue: when injected into the blood, the dye, like the blood proteins, is deposited in yolk spheres in the cortex of the oocyte. This behavior of trypan blue was first described in the scorpian fly by Ramamurty (1964), and has since been confirmed in a cricket (Sander & Vollmar, 1967) and in the cecropia moth (Telfer & Anderson, 1968). Ovarian follicles of the cecropia moth have also been exposed to trypan blue in vitro; under these conditions the dye is not only incorporated into cortical yolk spheres but is in addition bound at the oocyte surface and in the intercellular spaces which serve as passageways for blood proteins across the follicular epithelium.

scholarly journals HEMOGLOBIN ABSORPTION BY THE CELLS OF THE PROXIMAL CONVOLUTED TUBULE IN MOUSE KIDNEY

1960 ◽  
Vol 8 (3) ◽  
pp. 689-718 ◽  
Author(s):  
Fritz Miller
Keyword(s):  
Brush Border ◽  
Mouse Kidney ◽  
Intermediate Cell ◽  
Intercellular Spaces ◽  
Hemoglobin Content ◽  
Collecting Ducts ◽  
Tubular Lumen ◽  
Proximal Convolution ◽  
Cell Zone ◽  
Hemoglobin Absorption

The formation of protein absorption droplets in the cells of the proximal convolution was studied in mouse kidney. Ox hemoglobin was administered intraperitoneally and kidney specimens were collected at intervals of 30 minutes to 4 days after injection. In the lumen of the nephron, hemoglobin was concentrated to an opaque mass whose relations with the brush border and the epithelium could be easily followed. It was found that hemoglobin passes through the brush border in between the microvilli, enters the channels of tubular invaginations at the bases of the brush border, and is transported in bulk into vacuoles in the intermediate cell zone. These vacuoles increase in size and are transformed through further concentration into dense absorption droplets. Using the opaque hemoglobin content of the nephron as a tracer, functional continuity of the system of the tubular invaginations with the lumen on one side and the vacuoles on the other was demonstrated. Mitochondria lie closely apposed to vacuoles and droplets, but are not primarily involved in droplet formation. 15 hours after injection and later, ferritin and systems of layered membranes become visible in the droplets as their density decreases. These membranes are interpreted as lipoprotein membranes; similar membranes are found in the lumen of the tubuli. It is suggested that phospholipids enter into the vacuoles together with hemoglobin from the tubular lumen and form membrane systems of lipoproteins in the droplets. At 3 to 4 days the droplets contain aggregates of ferritin, and the iron reaction becomes positive in the tubule cells. No significant changes were found in the Golgi apparatus or in the microbodies during hemoglobin absorption. At all time points investigated, the terminal bars seal the intercellular spaces against penetration by hemoglobin in the proximal and distal convolutions and in the collecting ducts.

scholarly journals Studies on the Electrical Potential Profile across Rabbit Ileum

1971 ◽  
Vol 57 (6) ◽  
pp. 639-663 ◽  
Author(s):  
Richard C. Rose ◽  
Stanley G. Schultz
Keyword(s):  
Amino Acids ◽  
Brush Border ◽  
Electrical Potential ◽  
Metabolic Inhibitors ◽  
Electrical Potential Difference ◽  
Intercellular Spaces ◽  
Cell Interior ◽  
Rabbit Ileum ◽  
Lateral Intercellular Spaces ◽  
Rapid Replacement

When isolated strips of mucosal rabbit ileum are bathed by physiological electrolyte solution the electrical potential difference (PD) across the brush border (ψmc) averages 36 mv, cell interior negative. Rapid replacement of Na in the mucosal solution with less permeant cations, Tris or choline, results in an immediate hyperpolarization of ψmc. Conversely, replacement of choline in the mucosal solution with Na results in an abrupt depolarization of ψmc. These findings indicate that Na contributes to the conductance across the brush border. The presence of actively transported sugars or amino acids in the mucosal solution brings about a marked depolarization of ψmc and a smaller increase in the transmural PD (Δψms). It appears that the Na influx that is coupled to the influxes of amino acids and sugars is electrogenic and responsible for the depolarization of ψmc. Under control conditions Δψms can be attributed to the depolarization of ψmc together with the presence of a low resistance transepithelial shunt, possibly the lateral intercellular spaces. However, quantitatively similar effects of amino acids on ψmc are also seen in tissues poisoned with metabolic inhibitors or ouabain. Under these conditions Δψmc is much smaller than under control conditions. Thus, the depolarization of ψmc might not account for the entire Δψms, observed in nonpoisoned tissue. An additional electromotive force which is directly coupled to metabolic processes might contribute to the normal Δψms.

scholarly journals Hereditary Suprabasilar Acantholytic Mechanobullous Dermatosis in Buffaloes (Bubalus bubalis)

1994 ◽  
Vol 31 (4) ◽  
pp. 450-454 ◽  
Author(s):  
F. Riet-Correa ◽  
S. S. Barros ◽  
M. C. Dame ◽  
P. V. Peixoto
Keyword(s):  
Autosomal Recessive ◽  
Cell Layer ◽  
Single Layer ◽  
Bubalus Bubalis ◽  
Recessive Trait ◽  
Intercellular Spaces ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Stratum Spinosum ◽  
Histologic Evaluation

A skin disease characterized by trauma-induced sloughing of haired skin, hooves, and horns is described in four calves from a herd of Murrah buffaloes ( Bubalus bubalis) in Brazil. Affected calves were detected shortly after birth by the presence of lesions affecting the distal extremities, the scapular and gluteal regions, and the tip of the tail. On histologic evaluation of affected skin, the lesions were characterized by suprabasilar vesicles and acantholysis affecting the epidermis and outer root sheath of the hair follicle infundibulum. The basal cell layer was intact and appeared as a single layer of cuboidal cells attached to the dermis. Ultrastructurally, the region between the stratum basale and the lower stratum spinosum had widened intercellular spaces with loss of desmosomal attachments, which led to the suprabasilar separation. The disease appears to be inherited as an autosomal recessive trait.

scholarly journals Bucky ball establishes animal-vegetal polarity in the oocyte and in the follicle cell layer in zebrafish

2008 ◽  
Vol 319 (2) ◽  
pp. 464
Author(s):  
Florence L. Marlow ◽  
Franck Bontems ◽  
Roland Dosch ◽  
Mary C. Mullins
Keyword(s):  
Cell Layer ◽  
Follicle Cell ◽  
Bucky Ball

Fine Structure of the Hindgut of Armadillidium Vulgare

1971 ◽  
Vol 29 ◽  
pp. 414-415
Author(s):  
Laura Herold ◽  
G. M. Vernon ◽  
E. R. Witkus
Keyword(s):  
Fine Structure ◽  
Epithelial Cell ◽  
Cell Layer ◽  
The Other ◽  
Apical Region ◽  
Luminal Surface ◽  
Intercellular Spaces ◽  
Armadillidium Vulgare ◽  
Epithelial Cell Layer ◽  
Peripheral Cytoplasm

An ultrastructural study of the hepatopancreatic ducts and the hindgut of the terrestrial isopod, Armadillidium vulgare, reveals the presence of a single epithelial cell layer lined with cuticle. The cells of the duct lack the microvilli characteristic of the hepatopancreas and exhibit fewer apical infoldings than the cells of the hindgut. Basal infoldings, on the other hand, are common and relatively deep. Mitochondria are more abundant in the apical region of the cell than in the basal part. Bands of microtubules are present in the peripheral cytoplasm, and most of the microtubules run vertically in the cell from the luminal surface to the base (see fig. 1). Single membrane bounded vesicles of varying size were observed. These bodies contain moderately electron dense granular material. At the luminal surface the lateral membranes of adjacent cells are linked together by septate desmosomes. From the septate desmosome to the base of the cell there are relatively large intercellular spaces alternating with intermediate junctions or zona adherens.

Protein Synthesis and Uptake by Isolated Cecropia Oocytes

1971 ◽  
Vol 8 (3) ◽  
pp. 735-750
Author(s):  
LUCY M. ANDERSON
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Perchloric Acid ◽  
Selection Process ◽  
Ovarian Follicle ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Follicular Epithelium ◽  
Blood Proteins ◽  
Cell Product

A procedure has been developed for separating the oocytes and follicular epithelium-nurse cell complexes making up the vitellogenic ovarian follicle of the Cecropia moth. Both components remained viable during short-term in vitro incubation in female blood. Isolated epithelial cells were found by autoradiography to incorporate tritiated amino acids and to secrete a fixable, non-dialysable labelled material. Isolated oocytes incubated in a blood medium containing this tritiated, dialysed follicle cell product incorporated it in small cortical yolk bodies, presumably by pinocytosis. Quantitative perchloric acid-precipitation and scintillation counting indicated that the amount of labelled material incorporated by the oocytes increased with time. These results provide direct confirmation of a follicle contribution to the yolk. Isolated oocytes were also tested for their ability to incorporate labelled amino acids. Fixable label was observed autoradiographically throughout the oocyte cytoplasm, with the greatest concentration in the cortex, but little appeared in the yolk spheres. The amount of perchloric acid-precipitable amino acid in oocytes incubated in female blood increased with time for up to 2 h and then remained constant or decreased slightly. In medium that had been previously conditioned by follicle cells and dialysed, however, incorporation of labelled amino acid continued for at least 4 h. A possible interpretation of this result is that stimulation of pinocytosis by the epithelial cell products causes increased turnover of cell membrane and demands continued synthesis of new proteins. Labelled female blood proteins were not incorporated into yolk to an appreciable extent by isolated oocytes, even in the presence of follicle cell product. Perhaps extracellular preconcentration, as occurs in the intact follicle, is necessary for effective accrual of blood proteins. The female blood proteins did become associated with the oocyte cortex, however, and exhibited a higher affinity for the oocyte than male blood proteins. Thus preferential adsorption to the oocyte surface may be a component of the selection process in vitellogenesis.

RNAi-mediated inhibition of gene function in the follicle cell layer of theDrosophila ovary

genesis ◽  
2004 ◽  
Vol 40 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Xianjun Zhu ◽  
David Stein
Keyword(s):  
Gene Function ◽  
Cell Layer ◽  
Follicle Cell

Electron microprobe analysis of ouabain-exposed ciliary epithelium: PE-NPE cell couplets form the functional units

2004 ◽  
Vol 286 (6) ◽  
pp. C1376-C1389 ◽  
Author(s):  
Charles W. McLaughlin ◽  
Sylvia Zellhuber-McMillan ◽  
Anthony D. C. Macknight ◽  
Mortimer M. Civan
Keyword(s):  
Gap Junctions ◽  
Aqueous Humor ◽  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Epithelial Transport ◽  
Cell Layer ◽  
Ciliary Epithelium ◽  
Experimental Conditions ◽  
Freeze Dried

Aqueous humor is secreted by the bilayered ciliary epithelium. Solutes and water enter the pigmented ciliary epithelial (PE) cell layer, cross gap junctions into the nonpigmented ciliary epithelial (NPE) cell layer, and are released into the aqueous humor. Electrical measurements suggest that heptanol reduces transepithelial ion movement by interrupting PE-NPE communication and that gap junctions may be a regulatory site of aqueous humor formation. Several lines of evidence also suggest that net ciliary epithelial transport is strongly region dependent. Divided rabbit iris-ciliary bodies were incubated in chambers under control and experimental conditions, quick-frozen, cryosectioned, and freeze-dried. Elemental intracellular contents of NPE and PE cells were determined by electron probe X-ray microanalysis. With or without heptanol, ouabain produced concentration- and time-dependent changes more markedly in anterior than in posterior epithelium. Without heptanol, there were considerable cell-to-cell variations in Na gain and K loss. However, contiguous NPE and PE cells displayed similar changes, even when nearby cell pairs were little changed by ouabain in aqueous, stromal, or both reservoirs. In contrast, with heptanol present, ouabain added to aqueous or both reservoirs produced much larger changes in NPE than in PE cells. The results indicate that 1) heptanol indeed interrupts PE-NPE junctions, providing an opportunity for electron microprobe analysis of the sidedness of modification of ciliary epithelial secretion; 2) Na and K undergo faster turnover in anterior than in posterior epithelium; and 3) PE-NPE gap junctions differ from PE-PE and NPE-NPE junctions in permitting ionic equilibration between adjoining ouabain-stressed cells.

scholarly journals DRP1-dependent mitochondrial fission initiates follicle cell differentiation during Drosophila oogenesis

2012 ◽  
Vol 197 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Kasturi Mitra ◽  
Richa Rikhy ◽  
Mary Lilly ◽  
Jennifer Lippincott-Schwartz
Keyword(s):  
Cell Cycle ◽  
Cell Differentiation ◽  
Cell Layer ◽  
Mitochondrial Fission ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Developmental Defects ◽  
Drosophila Oogenesis ◽  
Regulated Expression ◽  
Regulatory Link

Exit from the cell cycle is essential for cells to initiate a terminal differentiation program during development, but what controls this transition is incompletely understood. In this paper, we demonstrate a regulatory link between mitochondrial fission activity and cell cycle exit in follicle cell layer development during Drosophila melanogaster oogenesis. Posterior-localized clonal cells in the follicle cell layer of developing ovarioles with down-regulated expression of the major mitochondrial fission protein DRP1 had mitochondrial elements extensively fused instead of being dispersed. These cells did not exit the cell cycle. Instead, they excessively proliferated, failed to activate Notch for differentiation, and exhibited downstream developmental defects. Reintroduction of mitochondrial fission activity or inhibition of the mitochondrial fusion protein Marf-1 in posterior-localized DRP1-null clones reversed the block in Notch-dependent differentiation. When DRP1-driven mitochondrial fission activity was unopposed by fusion activity in Marf-1–depleted clones, premature cell differentiation of follicle cells occurred in mitotic stages. Thus, DRP1-dependent mitochondrial fission activity is a novel regulator of the onset of follicle cell differentiation during Drosophila oogenesis.

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