scholarly journals Differential localizations of and requirements for the two Drosophila ninaC kinase/myosins in photoreceptor cells.

1992 ◽  
Vol 116 (3) ◽  
pp. 683-693 ◽  
Author(s):  
J A Porter ◽  
J L Hicks ◽  
D S Williams ◽  
C Montell
Keyword(s):  
Retinal Degeneration ◽  
Photoreceptor Cells ◽  
Kinase Domain ◽  
Electron Microscopic Level ◽  
Head Region ◽  
Electron Microscopic ◽  
Myosin I ◽  
Microvillar Structure ◽  
The Difference ◽  
The Individual

The ninaC gene encodes two retinal specific proteins (p132 and p174) consisting of a protein kinase domain joined to a domain homologous to the head region of the myosin heavy chain. The putative myosin domain of p174 is linked at the COOH-terminus to a tail which has some similarities to myosin-I tails. In the current report, we demonstrate that the ninaC mutation results in light- and age-dependent retinal degeneration. We also show that ninaC flies display an electrophysiological phenotype before any discernible retinal degeneration indicating that the electrophysiological defect is the primary effect of the mutation. This suggests that ninaC has a role in phototransduction and that the retinal degeneration is a secondary effect resulting from the defect in phototransduction. To examine the requirements for the individual ninaC isoforms, mutant alleles were generated which express only p132 or p174. Elimination of p174 resulted in a ninaC phenotype as strong as the null allele; however, elimination of p132 had little if any effect. As a first step in investigating the basis for the difference in requirements for p174 and p132 we performed immuno-localization at the electron microscopic level and found that the two isoforms display different subcellular distributions in the photoreceptor cells. The p132 protein is restricted primarily to the cytoplasm and p174 to the rhabdomeres, the microvillar structure which is the site of action of many of the steps in phototransduction. This suggests that the p174 myosin-I type tail is the domain responsible for association with the rhabdomeres and that the substrate for the p174 putative kinase may be a rhabdomeric protein important in photo-transduction.

Distribution of the myosin I-like ninaC proteins in the Drosophila retina and ultrastructural analysis of mutant phenotypes

1992 ◽  
Vol 101 (1) ◽  
pp. 247-254 ◽  
Author(s):  
J.L. Hicks ◽  
D.S. Williams
Keyword(s):  
Compound Eye ◽  
Photoreceptor Cells ◽  
Amino Acid Sequences ◽  
Ultrastructural Analysis ◽  
Multivesicular Bodies ◽  
Filamentous Actin ◽  
Electron Microscopic ◽  
Myosin I ◽  
Specific Proteins ◽  
Mutant Phenotypes

The Drosophila ninaC gene encodes for two head-specific proteins of 132 kDa and 174 kDa. Their predicted amino acid sequences indicate that they may have myosin I and kinase properties. We have: (1) determined the cellular and subcellular distributions of the ninaC proteins in the Drosophila retina by electron microscopic immunocytochemistry with an antibody specific for epitopes shared by both proteins; (2) characterized the ultrastructure of the mutant phenotype. The proteins were detected only in the photoreceptor cells, but were detected in all classes of the compound eye photoreceptors. Within the photoreceptors, they were found in the rhabdomeral microvilli and the cytoplasm adjacent to the rhabdomeres. This distribution coincides with that shown previously for actin filaments. Immunolabelling of tissue from the ninaC P221 mutant, which lacks the 174 kDa protein, and two mutants whose rhabdomeres degenerate, suggests that the 132 kDa protein is present primarily in the cytoplasm adjacent to the rhabdomeres, and that the 174 kDa protein is concentrated in the rhabdomeres. Our ultrastructural analysis showed that the axial cytoskeleton of the rhabdomeral microvilli (which contains filamentous actin) was absent in both the null and P221 mutants. In the photoreceptor cell cytoplasm, the number of multivesicular bodies in the null mutant, but not the P221 mutant, was 3-fold greater in comparison with wild-type.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and quantification of mitochondria-rich cells in transporting epithelia

1984 ◽  
Vol 246 (5) ◽  
pp. R770-R775 ◽  
Author(s):  
K. J. Karnaky ◽  
K. J. Degnan ◽  
L. T. Garretson ◽  
J. A. Zadunaisky
Keyword(s):  
Fluorescent Dyes ◽  
Short Circuit ◽  
Linear Regression Analysis ◽  
Cell Number ◽  
Electron Microscopic Level ◽  
Chloride Cells ◽  
Head Region ◽  
Electron Microscopic ◽  
Morphological Studies ◽  
Electron Microscopes

Fluorescent dyes specific for mitochondria have become important tools in the study of transporting epithelia. These dyes permit the localization and quantification of mitochondria-rich (MR) cells in these epithelia. To determine the specificity of the dye, dimethylaminostyrylmethylpyridiniumiodine ( DASPMI ), we combined fluorescence microscopy of this dye with the ultrastructural localization of the mitochondrial enzyme, cytochrome oxidase. Labeled cells were traced from the fluorescence-microscopic to the electron-microscopic level by devising several novel technical procedures. This new methodology assures a critical assessment of the specificity of fluorescent mitochondrial dyes in heterogeneous epithelia. Confirmation of DASPMI specificity allows the unequivocal identification of MR chloride cells in two epithelia in the head region of Fundulus heteroclitus and validates linear regression analysis of chloride cell number and short-circuit current in this species. In addition, this method provides a permanent, flat whole mount of labeled cells for morphological studies with the light microscope and with the scanning and transmission electron microscopes.

Effect of formaldehyde inhalation on rat livers: A light and electron microscopic study

2010 ◽  
Vol 26 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Selman Cikmaz ◽  
Tunc Kutoglu ◽  
Mehmet Kanter ◽  
Recep Mesut
Keyword(s):  
Liver Tissue ◽  
Exposure Period ◽  
Electron Microscopic Level ◽  
Albino Rats ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Microscopic Evaluation ◽  
Microscopic Studies ◽  
Wistar Albino Rats ◽  
The Individual

It is well known that formaldehyde (FA) is cytotoxic and potentially carcinogenic. Although the individual effects of this reactant on cells has been investigated, the cytotoxicity exerted by the coexistence of FA is poorly understood. The aim of this study was to investigate the effects of FA on the liver in rats, by light and electron microscopic level. We used 18 Wistar albino rats divided into three groups, exposed to 0 (control), 19.7 ppm FA gas for a total of 4 weeks, 8 h/day, 5 days a week (subacute) and 20.3 parts per million (ppm) FA gas for a total of 13 weeks, 8 h/day, 5 days a week (subchronic). After the completion of the exposure period, they were sacrificed by decapitation and their liver tissue samples were taken in order to be processed for light and electron microscopic studies. Light microscopic evaluation of liver tissue samples of FA-exposed rats revealed enlarged sinusoids filled with blood and mononuclear cell infiltration in the portal areas and around the central veins. In addition, some of the hepatocytes showed loss of cytoplasm, and some had a hyperchromatic nucleus. The cells of FA-exposed livers, on the other hand, showed an electron-lucent ground-cytoplasm and a hypertrophy of the smooth-surfaced endoplasmic reticulum. In conclusion, we observed that exposure FA caused diverse histopathological changes indicating the destruction in the liver tissue and this destruction has direct relationship with the length of the exposure period.

scholarly journals Unlabeled antibody methods in electron microscopy: a comparison of single and multistep procedures using colloidal gold.

1984 ◽  
Vol 32 (8) ◽  
pp. 799-804 ◽  
Author(s):  
E J Gosselin ◽  
G D Sorenson ◽  
J C Dennett ◽  
C C Cate
Keyword(s):  
New York ◽  
Colloidal Gold ◽  
Single Step ◽  
Electron Microscopic Level ◽  
Step Method ◽  
Electron Microscopic ◽  
Primary Antiserum ◽  
Antigen Localization ◽  
The Individual ◽  
Unlabeled Antibody

A comparative study of five unlabeled antibody methods was conducted on the electron microscopic level using bridging techniques and colloidal gold. The study was based on the principles of the single-step colloidal gold (GLAD) method (Larsson L: Nature 282:743, 1979) and the multistep single- and double-bridge techniques used in postembedding immunoperoxidase procedures (PAP) (Sternberger LA: Immunocytochemistry, 2nd ed. Wiley, New York, 1979). Using medullary thyroid carcinoma and the same lot of primary antiserum (goat anti-calcitonin) for each procedure, it was shown that adequate localization of calcitonin with the single-step GLAD method was attainable only at dilutions of 1:100 or lower. The single-bridge technique using goat anti-calcitonin, sheep anti-goat immunoglobulin (Ig)G, and goat anti-calcitonin and antigen-coated gold, respectively, worked well at dilutions of up to 1:5000 but not at dilutions of 1:10,000, while single- and double-bridging techniques utilizing goat anti-calcitonin, sheep (Sh) anti-goat IgG, and sheep anti-goat IgG-coated gold produced good localization at a 1:10,000 dilution of primary antiserum. A two-step method using goat anti-calcitonin and sheep anti-goat IgG-coated gold, respectively, appeared to be the most sensitive technique, with adequate antigen localization occurring at a dilution of 1:25,000. While in our hands the two-step method appeared superior in sensitivity to the single-bridge IgG-coated gold technique, each method has its own advantages depending on the individual needs of the researcher.

Sclerally directed processes of dopaminergic interplexiform cells reach the outer nuclear layer in rat and monkey retina

1990 ◽  
Vol 4 (6) ◽  
pp. 547-553 ◽  
Author(s):  
Jeanine Nguyen-Legros ◽  
Fatima Moussafi ◽  
Axelle Simon
Keyword(s):  
Tyrosine Hydroxylase ◽  
Outer Nuclear Layer ◽  
Photoreceptor Cells ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic

AbstractTyrosine hydroxylase-immunolabeled wholemounts and sections of rat and monkey retina were observed at both the light- and electron-microscopic level. Small processes derived from sclerally directed processes of dopaminergic interplexiform cells were observed ascending to the outer nuclear layer where they were distributed between photoreceptor cells. A role in the regulation of disc shedding and/or melatonin biosynthesis is proposed for dopamine released at this level.

Silver Staining of Pancreatic Islets as Revealed by Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 44-45
Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada
Keyword(s):  
Pancreatic Islet ◽  
Silver Staining ◽  
Islet Cells ◽  
Severe Hypoglycemia ◽  
Granular Cell ◽  
Electron Microscopic Level ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Pancreatic Islet Cell ◽  
D Cell

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

A New Technique for the Light and Electron Microscopic Study of Individual Cerebro-Spinal Fluid Cells in a Mona Plane Layer

1976 ◽  
Vol 34 ◽  
pp. 362-363
Author(s):  
L.A. Dell
Keyword(s):  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Plane Layer ◽  
Ultrastructural Level ◽  
Spinal Fluid ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Easy Method ◽  
Cell Pellet ◽  
A New Technique

A new method has been developed which readily offers the microscopist a possibility for both light and electron microscopic study of selected cells from the cerebrospinal fluid. Previous attempts to examine these cells in the spinal fluid at the ultrastructural level were based on modifications of cell pellet techniques developed for peripheral blood. These earlier methods were limited in application by the number of cells in spinal fluid required to obtain a sufficient size pellet and by the lack of an easy method of cellular identification between the light and electron microscopic level. The newly developed method routinely employs microscope slides coated with Siliclad and tungsten oxide for duplicate cytocentrifuge preparations of diagnostic spinal fluid specimens. Work done by Kushida and Suzuki provided a basis for our use of the metal oxide.

Electron Microscopic Analysis of Myonecrosis Induced by a Pure Component Isolated From Rattlesnake Venom

1976 ◽  
Vol 34 ◽  
pp. 292-293
Author(s):  
Charlotte L. Ownby ◽  
David Cameron ◽  
Anthony T. Tu
Keyword(s):  
Gel Filtration ◽  
Microscopic Analysis ◽  
The United States ◽  
Exchange Chromatography ◽  
Pure Component ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Mouse Muscle ◽  
Major Health Problem ◽  
Rattlesnake Venom

In the United States the major health problem resulting from snakebite poisoning is local tissue damage, i.e. hemorrhage and myonecrosis. Since commercial antivenin does not usually prevent such damage to tissue, a more effective treatment of snakebite-induced myonecrosis is needed. To aid in the development of such a treatment the pathogenesis of myonecrosis induced by a pure component of rattlesnake venom was studied at the electron microscopic level.The pure component, a small (4,300 mol. wt.), basic (isoelectric point of 9.6) protein, was isolated from crude prairie rattlesnake (Crotalus viridis viridis) venom by gel filtration (Sephadex G-50) followed by cation exchange chromatography (Sephadex C-25), and shown to be pure by electrophoresis. Selection of the myotoxic component was based on light microscopic observations of injected mouse muscle.

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