The effect of fixation procedures on the electron density of polysaccharide granules in Nocardia coralina

Robertson, John; Lyttleton, Pamela; Williamson, Keith I.; Batt, Richard D.

doi:10.1016/s0022-5320(75)80072-4

Cited by 23 publications

(10 citation statements)

References 21 publications

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“…The present results confirm previous data on the influence of fixation methods on the ultrastructural image of glycogen inclusions in prokaryotic and eukaryotic cells (Millonig & Marinozzi 1968, Vye & Fischman 1970, Robertson et al 1975, Robinson et al 1982, Silva & Macedo 1983. Double fixation with glutaraldehyde-osmium tetroxide results in strong staining of the granules in bacteria and mammals, whereas in osmium-fixed samples the granules appear electron-transparent (Robertson et al 1975).…”

Section: Discussionsupporting

confidence: 92%

“…The enhancement of glycogen contrast described in mammals by the use of osmium tetroxide fixatives containing potassium ferrocyanide (Karnowsky 1971, Robinson et al 1982) was also found in rainbow trout phagocytes, even when a prefixation with glutaraldehyde was not used (not shown). As reported for other biological materials (Vye & Fischman 1970, Robertson et al 1975, Silva & Macedo 1983, the polysaccharide granules of trout neutrophils were found as electron-transparent areas whenever a postfixation with uranyl acetate was used.…”

Section: Discussionsupporting

confidence: 66%

“…Double fixation with glutaraldehyde-osmium tetroxide results in strong staining of the granules in bacteria and mammals, whereas in osmium-fixed samples the granules appear electron-transparent (Robertson et al 1975). The same was now observed for rainbow trout phagocytes.…”

Section: Discussionsupporting

confidence: 56%

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Glycogen granules in resting and inflammatory rainbow trout phagocytes-an ultrastructural study

Afonso¹,

Macedo²,

Ellis³

et al. 2000

Dis. Aquat. Org.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 66%

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Glycogen granules in resting and inflammatory rainbow trout phagocytes-an ultrastructural study

Afonso¹,

Macedo²,

Ellis³

et al. 2000

Dis. Aquat. Org.

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“…These regions were less electron dense than the stroma and probably contained the soluble polysaccharide. To investigate whether this was the case, we pretreated similar sections by using a silver proteinate method to stain glucan polymers (Robertson et al, 1975). Microscopy ( Figures 9E to 9G) revealed the presence of small glucan particles in the mutant that were ‫52ف‬ nm in size.…”

Section: Starch and Phytoglycogen Accumulate In The Same Chloroplastsmentioning

confidence: 99%

“…Sections were stained with uranyl acetate and lead citrate and viewed with a transmission electron microscope (model JEM-1200 EX; Jeol Ltd., London, UK). Sections were stained for the presence of carbohydrate by using the silver proteinate method described by Robertson et al (1975).…”

Section: Electron Microscopymentioning

confidence: 99%

A Mutant of Arabidopsis Lacking a Chloroplastic Isoamylase Accumulates Both Starch and Phytoglycogen

et al. 1998

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In this study, our goal was to evaluate the role of starch debranching enzymes in the determination of the structure of amylopectin. We screened mutant populations of Arabidopsis for plants with alterations in the structure of leaf starch by using iodine staining. The leaves of two mutant lines stained reddish brown, whereas wild-type leaves stained brownish black, indicating that a more highly branched polyglucan than amylopectin was present. The mutants were allelic, and the mutation mapped to position 18.8 on chromosome 1. One mutant line lacked the transcript for a gene with sequence similarity to higher plant debranching enzymes, and both mutants lacked a chloroplastic starch-hydrolyzing enzyme. This enzyme was identified as a debranching enzyme of the isoamylase type. The loss of this isoamylase resulted in a 90% reduction in the accumulation of starch in this mutant line when compared with the wild type and in the accumulation of the highly branched water-soluble polysaccharide phytoglycogen. Both normal starch and phytoglycogen accumulated simultaneously in the same chloroplasts in the mutant lines, suggesting that isoamylase has an indirect rather than a direct role in determining amylopectin structure.

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Studies related to the head‐maturation pathway of bacteriophages T4 and T2: I. Morphology and kinetics of intracellular particles produced by mutants in the maturation genes

Wunderli

Kellenberger

1977

J Supramol Struct

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Mutants in the genes governing the maturation of the head of bacteriophage T4 and in gene 24 were studied by electron microscopy of thin sections. We define morphologically: black particles, comprising mature, stable heads and immature, fragile heads, which break down upon lysis; grizzled particles, which apparently are partially filled or partially emptied; empty large particles without DNA or core which are all the same size as normal heads; empty small particles without DNA and without core which are of the size of the tau particle, which is the prehead of phage T4. The study of single and double mutants of the maturation genes demonstrates that the phenotypes are only different by the proportions of the different particles made except for 17- where only empty small and empty large particles accumulate. The mutants in gene 24 are epistatic on all other mutants. Mutants in gene 17 are epistatic on the remaining ones. The results are consistent with the hypothesis that the products of several of the maturation genes act on DNA to render it competent for packaging while the others act directly on the particle. By this uncoupling, bypasses and abortive pathways can result.

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The effect of fixation procedures on the electron density of polysaccharide granules in Nocardia coralina

Cited by 23 publications

References 21 publications

Glycogen granules in resting and inflammatory rainbow trout phagocytes-an ultrastructural study

Glycogen granules in resting and inflammatory rainbow trout phagocytes-an ultrastructural study

A Mutant of Arabidopsis Lacking a Chloroplastic Isoamylase Accumulates Both Starch and Phytoglycogen

Studies related to the head‐maturation pathway of bacteriophages T4 and T2: I. Morphology and kinetics of intracellular particles produced by mutants in the maturation genes

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