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1.
INORGANIC CATIONS IN RAT KIDNEY : Localization with Potassium Pyroantimonate-Perfusion Fixation 总被引:4,自引:3,他引:1
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For localization of pyroantimonate-precipitable cations, rat kidney was fixed by perfusion with a saturated aqueous solution of potassium pyroantimonate (pH about 9.2, without addition of any conventional fixative). A remarkably good preservation of the tissue and cell morphology was obtained as well as a consistent and reproducible localization of the insoluble antimonate salts of magnesium, calcium, and sodium. All proximal and distal tubules and glomeruli were delimited by massive electron-opaque precipitates localized in the basement membrane and, to a lesser extent, in adjacent connective tissue. In the intraglomerular capillaries the antimonate precipitate was encountered in the basement membranes and also between the foot processes. In addition to a more or less uniform distribution in the cytoplasm and between the microvilli of the brush border, antimonate precipitates were found in all cell nuclei, mainly between the masses of condensed chromatin. The mitochondria usually contained a few large antimonate deposits which probably correspond to the so-called "dense granules" observed after conventional fixations. 相似文献
2.
Summary Mineral components of the scales in an amoeba, Cochliopodium sp., were examined by energy-dispersive X-ray microanalysis. The precipitates in potassium antimonate-treated material detected calcium in the scales. Calcium was also clearly detected in freeze-substituted thin sections. Similar deposits of calcium antimonate were detected in scales in formation within vacuoles, and also in Golgi cisternae, Golgi vesicles and special granules near the nucleus. There were only minute amounts of magnesium and potassium. This suggests that calcium is the main mineral component of the scales and that it is added in the Golgi complex during scale formation. 相似文献
3.
Selective subcellular localization of cations with variants of the potassium (pyro)antimonate technique. 总被引:4,自引:0,他引:4
Fixation of rat parotid with an unbuffered osmium tetroxide solution containing nearly saturated potassium (pyro)antimonate resulted in abundant deposition of cation-antimonate precipatates in acinar cells. Altering the antimonate concentration, including buffers or chelators in the solution or changing the primary fixative resulted in an altered intensity and distribution of the precipitates formed in the tissue, apparently reflecting a degree of selectivity in ion localization. Decreasing the concentration of pyroantimonate to about half-saturation preserved predominantly the less soluble antimonate salts (e.g., Na+, Ca++) and resulted in preferential retention of deposits along the plasmalemma and in mitochondrial "dense bodies," with loss of most cytoplasmic and nuclear precipitates. A similar pattern was seen if fixation with the high concentration antimonate-osmium procedure was followed by a prolonged rinse. Adding phosphate or collidine buffers markedly decreased precipitates in the nuclei and on granular reticulum as well. Phosphate buffer or ehtyleneglycoltetraacetate inhibited in vitro precipitation of calcium and sodium and decreased or abolished plasmalemmal deposits. Glutaraldehyde fixation, either in the presence of antimonate or prior to antimonate-containing osmium tetroxide, abolished heterochromatin deposits. Mitochondrial dense bodies were of two types, one containing precipitate and the other inherently osmiophilic. The latter were also observed in pyrophosphate-osmium controls. Results from in vitro titrations of cations with the various antimonate methods and from neutron activation analyses of fixed tissues supported conclusions drawn from fine structural distribution patterns and were interpreted as follows. In rat parotid acinar cells, deposits in heterochromatin and on granular reticulum probably arose from precipitation in sites of high K+ and H+ as well as--NH3+-rich histones. Plasmalemmal antimonate deposits demonstrated sites of sodium and/or calcium accumulation. Some mitochondrial dense bodies contained Ca++ whereas others were inherently osmiophilic. Large, extracellular deposits were probably predominantly sodium precipitates. 相似文献
4.
OBSERVATIONS ON THE FINE STRUCTURE OF THE MACRONUCLEUS OF TOKOPHRYA INFUSIONUM 总被引:7,自引:7,他引:0
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The macronucleus in Tokophrya infusionum is composed of numerous Feulgen-positive chromatin bodies (about 0.5 µ in diameter) which appear in thin sections as a dense spongework, homogeneous throughout. The same appearance characterizes metaphase chromosomes of higher forms. Some chromatin bodies of the macronucleus were found to possess a highly organized structure in certain old organisms. This structure appears in cross-sections as a honeycomb and in longitudinal sections as parallel lines about 120 A in diameter evenly spaced (about 230 A). As far as is known this is the first time a regular structure has been found in bodies of chromosomal character at the dimensional level presently explored by electron microscopy. The demonstration that OsO4 can preserve order in chromatin material is another significant aspect of these findings. 相似文献
5.
Background
The aim of this work was to study how evenly detoxifying genes are transcribed spatially in liver tissue of fish. Ten Atlantic salmon Salmo salar were intraperitoneally injected with 50 mg/kg of the strong CYP1A inducer β-naphthoflavone and liver tissue harvested seven days later. The liver from 10 control and 10 exposed fish were split into eight sections, RNA extracted and three reference (β-actin, elongation factor 1AB (EF1AB)) and two detoxifying genes (CYP1A and GST) quantified with real-time RT-PCR. The cellular localization of the EF1AB and CYP1A mRNA in the liver of control and β-naphthoflavone treated fish was then determined by in situ hybridization (ISH) using EF1AB and CYP1A biotinylated oligonucleotide probes. 相似文献6.
《Experimental mycology》1983,7(3):266-277
The osmium tetroxide-potassium pyroantimonate technique was used to detect cations in zoospores ofChytriomyces hyalinus. Electron-opaque precipitates were located on the fenestrated and closed cisternal portions of rumposomes in zoospores. Precipitates also appeared in the fenestrae of rumposomes, in mitochondria, in lipid globules, and on the plasma membrane. Ethylene glycol bis(β-aminoethyl ether)N,N′-tetraacetic acid, which selectively chelates calcium ions, removed most of the precipitates from sections of rumposomes, mitochondria, and lipid globules, indicating the electron-opaque material was antimonate precipitates of calcium ions concentrated in these organelles. The localization of calcium in therumposome and the close association of the rumposome with the flagellar apparatus suggest a role for the rumposome in the regulation of flagellar activities. 相似文献
7.
Localization of a novel recessive powdery mildew resistance gene from common wheat line RD30 in the terminal region of chromosome 7AL 总被引:4,自引:0,他引:4
Singrün Ch Hsam SL Zeller FJ Wenzel G Mohler V 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):210-214
Segregation analysis of resistance to powdery mildew in a F2 progeny from the cross Chinese Spring (CS) × TA2682c revealed the inheritance of a dominant and a recessive powdery mildew resistance gene. Selfing of susceptible F2 individuals allowed the establishment of a mapping population segregating exclusively for the recessive resistance gene. The extracted resistant derivative showing full resistance to each of 11 wheat powdery mildew isolates was designated RD30. Amplified fragment length polymorphism (AFLP) analysis of bulked segregants from F3s showing the homozygous susceptible and resistant phenotypes revealed an AFLP marker that was associated with the recessive resistance gene in repulsion phase. Following the assignment of this AFLP marker to wheat chromosome 7A by means of CS nullitetrasomics, an inspection of simple sequence repeat (SSR) loci evenly spaced along chromosome 7A showed that the recessive resistance gene maps to the distal region of chromosome 7AL. On the basis of its close linkage to the Pm1 locus, as inferred from connecting partial genetic maps of 7AL of populations CS × TA2682c and CS × Virest (Pm1e), and its unique disease response pattern, the recessive resistance gene in RD30 was considered to be novel and tentatively designated mlRD30.Communicated by C. Möllers 相似文献
8.
W. F. Neiss 《Histochemistry and cell biology》1988,88(3-6):603-612
Summary LR White is a well-suited resin for the demonstration of carbohydrates with the PAS or PA-TCH-SP reaction in semithin and ultrathin sections. The intensity of these reactions can be greatly enhanced by using 3 steps in tissue preparation, either singly or in combination:1) The PAS reaction in semithin sections turns out stronger afterpartial (70% ethanol) than complete (100% ethanol)dehydration of the tissue before its transfer to 100% LR White.2)Silver enhancement of the PA-TCH-SP reaction product can simply be effected by physical development of ultrathin sections (PA-TCH-SP-SE reaction). Least precipitates are formed in this procedure, when sections are mounted on uncoated gold grids, processed for cytochemistry, and thinly coated with carbon in the end.3) The use ofhot silver proteinate (50° C) plus strong silver enhancement (15–20 min silver lactate developer) reveals minute concentrations of TCH-labelled aldehyde groups in the tissue that do not react with silver proteinate at room temperature.-Silver enhancement and the use of hot silver proteinate do not depend on LR White, but may also be applied to ultrathin sections of tissue embedded in other resins.Dedicated to Professor Dr. T.H. Schiebler on the occasion of his 65th birthday 相似文献
9.
Localization of calcium in the pericarp cells of tomato fruits during the development of blossom-end rot 总被引:3,自引:0,他引:3
Summary. Blossom-end rot (BER) of tomato (Lycopersicon esculentum) fruits is considered to be a physiological disorder caused by calcium deficiency. We attempted to clarify the localization of calcium in the pericarp cells and the ultrastructural changes during the development of BER. Calcium precipitates were observed as electron-dense deposits by an antimonate precipitation method. Some calcium precipitates were localized in the cytosol, nucleus, plastids, and vacuoles at an early developmental stage of normal fruits. Calcium precipitates were increased markedly on the plasma membrane during the rapid-fruit-growth stage compared with their level at the early stage. Cell collapse occurred in the water-soaked region at the rapid-fruit-growth stage in BER fruits. There were no visible calcium precipitates on the traces of plasma membrane near the cell wall of the collapsed cells. The amount of calcium precipitates on plasma membranes near collapsed cells was smaller than that in the cells of normal fruits and normal parts of BER fruits, and the amount on cells near collapsed cells was small. The amount of calcium precipitates on the plasma membranes increased as the distance from collapsed cells increased. On the other hand, calcium precipitates were visible normally in the cytosol, organelles, and vacuoles and even traces of them in collapsed cells. The distribution pattern of the calcium precipitates on the plasma membrane was thus considerably different between normal and BER fruits. On the basis of these observations, we concluded that calcium deficiency in plasma membranes caused cell collapses in BER tomato fruits.Correspondence and reprints: National Institute of Vegetable and Tea Science, National Agricultural Research Organization, Ano, Mie, 514-2392, Japan. 相似文献
10.
An improved method for the subcellular localization of calcium using a modification of the antimonate precipitation technique 总被引:2,自引:0,他引:2
A new variation of the antimonate precipitation technique, employing tannic acid in the primary aldehyde-antimonate fixative, is described for use in the subcellular localization of calcium in various tissues. Chelation studies and electron microscopic, X-ray microanalytical studies of antimonate precipitates in etiolated oat tissues indicate that calcium is the major cation localized using the present experimental protocol. Preservation of ultrastructural morphology in these tissues is greatly improved over that observed in tissues fixed with conventional antimonate-aldehyde or antimonate-osmium fixatives. The regularity and reproducibility of tissue precipitate patterns suggests that 1) penetration of the tissue by the fixative, and subsequent precipitation of calcium, is rapid and uniform and 2) ion displacement during sample preparation is negligible. Calcium appears to be immobilized efficiently in situ, with greater than 90% 45Ca retention in radiolabeled tissues prepared for electron microscopy. Quantitative aspects of calcium precipitation by antimonate in 45Ca-labeled CaCl2 solutions were examined over a wide range of calcium concentrations. Precipitation was essentially linear over the expected range of biological concentrations of calcium. Furthermore, the 3:1 antimonate to calcium ratio estimated for test tube precipitates was also established for Sb/Ca in tissue precipitates analyzed using energy dispersive x-ray microanalytical (EDX) techniques. These observations suggest that the present technique is potentially useful in the semiquantitative estimation of tissue calcium levels. 相似文献
11.
THE DISTRIBUTION OF INORGANIC CATIONS IN MOUSE TESTIS : Electron Microscope and Microprobe Analysis 总被引:2,自引:2,他引:0
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Abraham L. Kierszenbaum Cesar M. Libanati Carlos J. Tandler 《The Journal of cell biology》1971,48(2):314-323
For localization of pyroantimonate-precipitable cations, mouse testes were fixed with a saturated aqueous solution of potassium pyroantimonate (pH about 9.2, without addition of any conventional fixative), hardened with formaldehyde, and postosmicated. A good preservation of the cell membranes and over-all cell morphology is obtained as well as a consistent and reproducible localization of the insoluble antimonate salts of magnesium, calcium, and sodium. Four sites of prominent antimonate deposits are revealed, besides a more or less uniform distribution of the precipitates. These sites are: (a) In the walls of the seminiferous tubules, localized in two concentric layers corresponding to the inner and outer layers of the tubular wall; (b) Around the blood vessels and adjacent connective tissue; (c) At the area of contact between the Sertoli cell and spermatids, where a double line of precipitate surrounds the head of the mature spermatids; and (d) In the cell nuclei, disposed between regions of the condensed chromatin. The nucleus of mature spermatids did not show any sign of antimonate precipitation. The implications of this inorganic cation distribution are discussed with relation to their anionic counterparts, their localization in other animal and plant tissues, and the possibility that those sites may represent barriers to the free passage of ions. 相似文献
12.
Potassium antimonate was used to localize Ca2+ in tobacco ovules from 0 to 7 d after anthesis in pollinated and emasculated flowers. Antimonate binds “loosely bound” Ca2+ into calcium antimonate; less-soluble forms are unavailable and free calcium usually escapes. Ovules are immature at anthesis.
Abundant calcium precipitates in nucellar cells surrounding the micropylar canal. A difference between calcium in the two
synergids emerges at 1 d, which is enhanced in pollinated flowers. The future receptive synergid accumulates more precipitates
in the nucleus, cytoplasm and cell walls. After fertilization, micropyle precipitates diminish, and the ovule is unreceptive
to further tube entry. In emasculated flowers 6 d after anthesis, ovular precipitates essentially disappear; however, flowers
pollinated at 4–5 d and collected 2 d later largely restore their prior concentration of precipitates. Ovular precipitates
occur initially in the nucellus, then the embryo sac, and finally the synergid and micropylar filiform apparatus. Possibility,
calcium is released from the embryo sac, although no structural evidence of exudate formation was observed. Calcium precipitates
in the ovule correlate with the ability of the ovule to be fertilized, suggesting that successful pollen tube entry and later
development may require calcium of the class precipitated by antimonate.
Received: 14 August 1996 / Accepted: 9 October 1996 相似文献
13.
Distribution of calcium in the stigma and style of tobacco during pollen germination and tube elongation 总被引:1,自引:0,他引:1
Potassium antimonate was used to locate loosely bound calcium in the stigma and style of tobacco. The tobacco stigma is wet
and covered by a thick layer of glycoprotein exudate at anthesis. The exudate contains abundant vesicles, which are densely
labeled with calcium precipitates. When pollen grains arrive at the stigma, become hydrated, and as the pollen swells, Ca2+ precipitates accumulate at the aperture. Calcium precipitates that accumulate in pollen cytoplasm are initially concentrated
within small vacuoles, but as germination proceeds these appear to fuse, forming prominent, densely labeled vesicles that
preferentially accumulate near the proximal region of the growing tube. Although the stigma has abundant particles, few calcium
precipitates are observed in the transmitting tissue from anthesis to 11 h after pollination. However, at 22 h after pollination,
accumulation of calcium increases distally from the stigmatic interface with the transmitting tissue through the length of
the style to the ovary. An examination of flowering plants with differing floral biology will be needed to understand the
role of loosely bound calcium accumulation and its relationship to tissue-level changes in calcium uptake, maintenance of
other calcium pools, including [Ca2+]cyt, and in pollen and style maturation during the progamic phase. 相似文献
14.
MSX-resistant mutants of Anabaena 7120 with derepressed heterocyst development and nitrogen fixation
To investigate the role of ammonium-assimilating enzyme in heterocyst differentiation, pattern formation and nitrogen fixation, MSX-resistant and GS-impaired mutants of Anabaena 7120 were isolated using transposon (Tn5-1063) mutagenesis. Mutant Gs1 and Gs2 (impaired in GS activity) exhibited a similar rate of nitrogenase activity compared to that of the wild type under dinitrogen aerobic conditions in the presence and absence of MSX. Filaments of Gs1 and Gs2 produced heterocysts with an evenly spaced pattern in N2-grown conditions, while addition of MSX altered the interheterocyst spacing pattern in wild type as well as in mutant strains. The wild type showed complete repression of heterocyst development and nitrogen fixation in the presence of NO3
– or NH4
+, whereas the mutants Gs1 and Gs2 formed heterocysts and fixed nitrogen in the presence of NO3
– and NH4
+. Addition of MSX caused complete inhibition of glutamine synthetase activity in wild type but Gs1 and Gs2 remained unaffected. These results suggest that glutamine but not ammonium is directly involved in regulation of heterocyst differentiation, interheterocyst spacing pattern and nitrogen fixation in Anabaena. 相似文献
15.
Summary The application of anti-prostaglandin E2 immunoglobulin to plastic-embedded thin sections of the rat ileum has permitted the localization of prostaglandin E2 in this tissue. In agreement with the published data (Chock & Schmauder-Chock (1988), Schmauder-Chock & Chock (1989)), the results also suggest the presence of an arachidonic acid cascade in the granules of various secretory cells of the gut. Since antibody labelling was found within the secretory granules of connective tissue mast cells, goblet cells, and Paneth cells, the presence of the arachidonic acid cascade in these granules is implied. The appearance of prostaglandin E2 over the non-cellular internal elastic lamina of arterioles suggests that it may have been secreted along with the elastin. The even distribution of prostaglandin throughout the cytoplasm of the erythrocyte is consistent with the concept that this cell scavenges the eicosanoid from the circulation. These data further link the secretorh granule to the production of eicosanoids and therefore illustrate the potential sources of prostaglandins in the rat ileum. 相似文献
16.
Deposition pattern of hydrogen peroxide (H2O2) under salt stress (100 mM NaCl) was examined cytochemically in rice (Oryza sativa L. cv. Pokkali) through the reaction of H2O2 with cerium chloride (CeCl3) to produce electron dense precipitates of cerium perhydroxide. The distribution pattern of cerium perhydroxide precipitates
in leaf sheath was considerably different from other parts of rice under salinity stress. Cerium perhydroxide precipitates
were mainly accumulated on the tonoplast of leaf sheath under salinity, although they were localized on the cell wall and
plasma membrane in all other tissues such as leaf blade and root. 相似文献
17.
Frank Van Iren Loulou Van Essen-Joolen Paula Van der Duyn Schouten Pinie Boers-Van der Sluijs W. C. de Bruijn 《Histochemistry and cell biology》1979,63(3):273-294
Summary Komnick's antimonate technique, which was devised to localize Na+ in cells and tissues, was studied quantitatively. Some modifications, as well as its application to Ca2+ localization, were also investigated.We combined measurements of Na+ and Ca2+ retention in plant roots during the various procedures, electron microscopy, autoradiography, and semiquantitative X-ray microanalysis. We were able to show that (at least in barley roots) antimonate does not precipitate at all with Na+, irrespective of the Na+ content of the tissue or the method of antimonate application. (Even during precipitative freeze dissolution or after freeze drying, no Na+ is precipitated.) By means of Komnick's antimonate technique Ca2+ is trapped within the tissue, but only after serious dislocation. Perspectives for reliable localization of diffusible ions in cells and tissues, by precipitation simultaneously with conventional fixations, are bad. 相似文献
18.
Walther Stoeckenius 《The Journal of cell biology》1959,5(3):491-500
In the electron microscope, thin sections of OsO4-fixed myelin figures from the phospholipide fraction of human brain show a pattern of parallel dark lines with a repeating period of about 40 A. It is shown that the dark lines probably represent the reaction product of OsO4 with double bonds in the fatty acid chains, thereby marking the central portion of one bimolecular lamella. The addition of globin results in dense lines 25 to 50 A wide that cover the surface of the myelin figures. When such a figure consists of only two bimolecular leaflets of lipide covered with globin, the structure shows striking similarity to the image of cell membranes in fixed tissue sections. A hypothetical schema is given of the molecular structure of the figure, and the distribution of OsO4 in it. 相似文献
19.
High-level expression offtsA, an essential cell division gene inEscherichia coli, inhibits cell septation and causes the formation of filaments that develop spherical bulges up to 4 m in diameter. These bulges may emanate from septation sites, since they were evenly spaced in relation to one another and to the cell poles. Electron microscopic examination of thin sections through the bulged regions reveals large electron-lucent, plate-like regions that appear to originate from the membrane. In addition, these bulging filamentous cells contain more hexosamine per mass than control cells. A model is proposed that the electron-lucent regions observed by electron microscopy are caused by peptidoglycan accumulation stimulated by the overexpression offtsA. 相似文献
20.
Summary The synergids and other cells of mature, unpollinated pearl millet ovaries were investigated using: (1) freeze-substitution fixation in conjunction with scanning electron microscope observations and energy-dispersive X-ray microanalysis to localize total calcium (Ca) and other elements, and (2) antimonate precipitation to selectively localize loosely sequestered, exchangeable calcium (Ca++). In freeze-fixed ovaries, the synergid cells, ovary wall, nucellus, and other regions of the ovary displayed, respectively and relatively, extremely high, high, moderate, and low levels of Ca. In antimonate-fixed ovaries, Ca-containing antimonate precipitates exhibited similar distribution patterns. In ovaries fixed using the conventional 2% (w/v) antimonate in fixatives, the synergids were disrupted due to precipitate overload. In the ovary wall, precipitates were mainly located in the intercellular spaces. Some precipitates were observed at the micropyle and along the outer ovule integument, associated with diffuse extracellular material, and in the cell walls of nucellar cells proximal to the micropyle. Examination of precipitate distribution inside the synergids was possible in ovaries fixed using 0.5% (w/v) antimonate in the fixatives. Cytoplasmic organelles of all synergids examined exhibited variable states of disintegration. The amount of precipitates associated with the degenerated organelles appeared to be proportional to the degree of their degeneration. Distinct precipitates were localized in contiguous regions of the nucellar cells fused with the embryo sac, the micropylar half of the embryo sac wall, and the filiform apparatus. The results are discussed in relation to the involvement of Ca++ in mediating the functions of synergid cells during fertilization in angiosperms.On Specific Cooperative Agreement 58-43YK-8-0026 with the Department of Biochemistry, University of Georgia, Athens, GA 30602, USA 相似文献