Electron Microscopy of Mycoplasma Pneumoniae

Author(s):  
E. S. Boatman ◽  
G. E. Kenny

Information concerning the morphology and replication of organism of the family Mycoplasmataceae remains, despite over 70 years of study, highly controversial. Due to their small size observations by light microscopy have not been rewarding. Furthermore, not only are these organisms extremely pleomorphic but their morphology also changes according to growth phase. This study deals with the morphological aspects of M. pneumoniae strain 3546 in relation to growth, interaction with HeLa cells and possible mechanisms of replication.The organisms were grown aerobically at 37°C in a soy peptone yeast dialysate medium supplemented with 12% gamma-globulin free horse serum. The medium was buffered at pH 7.3 with TES [N-tris (hyroxymethyl) methyl-2-aminoethane sulfonic acid] at 10mM concentration. The inoculum, an actively growing culture, was filtered through a 0.5 μm polycarbonate “nuclepore” filter to prevent transfer of all but the smallest aggregates. Growth was assessed at specific periods by colony counts and 800 ml samples of organisms were fixed in situ with 2.5% glutaraldehyde for 3 hrs. at 4°C. Washed cells for sectioning were post-fixed in 0.8% OSO4 in veronal-acetate buffer pH 6.1 for 1 hr. at 21°C. HeLa cells were infected with a filtered inoculum of M. pneumoniae and incubated for 9 days in Leighton tubes with coverslips. The cells were then removed and processed for electron microscopy.

Author(s):  
Joseph E. Mazurkiewicz

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.


2017 ◽  
Vol 6 (12) ◽  
pp. 1845
Author(s):  
Büyükkartal Hatice Nurhan ◽  
Hatice Çölgeçen ◽  
Ümit Budak

The genus Senecio L. belongs to the tribe Senecioneae Cass. of the family Asteraceae which is the richest plant family of Turkey in terms of endemic species. The study was conducted on a total of 8 taxa belonging to Senecio. 4 taxa were collected from West and 4 were collected from East Anatolia. Stem and leaf anatomy of the taxa were studied by light microscopy; achene structure was examined by light microscopy and transmission electron microscopy in order to identify morphological, anatomical and histological modifications and resolve taxonomic problems of the genus.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 35-39 ◽  
Author(s):  
L.T. Angenent ◽  
D. Zheng ◽  
S. Sung ◽  
L. Raskin

An anaerobic migrating blanket reactor (AMBR) was seeded with flocculent biomass from a digester and fed a substrate consisting of volatile fatty acids and sucrose to study granulation. After three months of operation, a mature granular blanket developed in the reactor. Moreover, fibers of approximately 1 cm long had become prevalent in the AMBR. Scanning electron microscopy (SEM) and light microscopy revealed a very dense structure consisting of bundles of filaments resembling Methanosaeta cells. Further studies with fluorescence in-situ hybridization (FISH), showed that Methanosaeta concilii was the predominant microorganism in these fibers.


1982 ◽  
Vol 39 (2) ◽  
pp. 139-148 ◽  
Author(s):  
Kathryn A. Raphael ◽  
R. E. Chapman ◽  
Penelope A. Frith ◽  
Pamela R. Pennycuik

SummaryThe hairs and follicles from mice carrying the naked (N) gene have been examined using both scanning and transmission electron microscopy in addition to light microscopy. Fibre cuticle cells and occasionally cortical cells were absent from the follicles of N / + mice when the base of the hair was growing. In N / N follicles there was a frequent lack of both cuticle and cortical cells throughout the growth phase of the follicles. Abnormalities were also observed in the manner in which the synthesized keratin was deposited in the fibres. The possible mode of action of the N gene is discussed in the light of these results.


2021 ◽  
Vol 63 (9) ◽  
pp. 19-24
Author(s):  
Hong Quang Bui ◽  
◽  

This paper uses scanning electron microscopy (SEM) analyses and light microscopy (LM) to study pollen grains of species of the family Oleaceae Hoffmanns. & Link distributed in Vietnam, including 23 species belonging to 6 genera of the family (Oleaceae). Pollen grains of all species (Oleaceae) in Vietnam are isopolar, radial, 3- prolate pollen grains small size, with two types: subprolate type (Jasminum and Olea) and prolate spheroidal type (Jasminum, Fraxinus, Ligustrum, Osmanthus, and Chengiodendron). The surface of the pollen grains in most species is reticulate. These are important morphological features to classify the Nhai family through pollen morphology


Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 333-339 ◽  
Author(s):  
John E. Dillé ◽  
Douglas C. Bittel ◽  
Kathleen Ross ◽  
J. Perry Gustafson

The scanning electron microscope may be useful in the analysis of plant chromosomes treated with in situ hybridization, especially when the probes and (or) chromosomes are near or beyond the resolution of the light microscope. Usual methods of plant chromosome preparation are unsuitable for scanning electron microscope observation as a result of cellular debris, which also interferes with probe hybridization. A method is described whereby protoplasts are obtained from fixed root tips by enzymatic digestion and applied to slides in a manner that produces little or no cellular debris overlying the chromosomes. The slides were examined by scanning electron microscopy and light microscopy after C-banding and in situ hybridization with a rye nucleolus organizer region spacer probe. This technique, which allows for scanning electron microscope visualization of bands and probes not easily identified with light microscopy, should prove useful in the physical mapping of low copy number or unique DNA sequences.Key words: protoplasts, rice, wheat, rye, physical maps, in situ hybridization.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11912
Author(s):  
Gita G. Paskerova ◽  
Tatiana S. Miroliubova ◽  
Andrea Valigurová ◽  
Jan Janouškovec ◽  
Magdaléna Kováčiková ◽  
...  

Background Gregarines are a major group of apicomplexan parasites of invertebrates. The gregarine classification is largely incomplete because it relies primarily on light microscopy, while electron microscopy and molecular data in the group are fragmentary and often do not overlap. A key characteristic in gregarine taxonomy is the structure and function of their attachment organelles (AOs). AOs have been commonly classified as “mucrons” or “epimerites” based on their association with other cellular traits such as septation. An alternative proposal focused on the AOs structure, functional role, and developmental fate has recently restricted the terms “mucron” to archigregarines and “epimerite” to eugregarines. Methods Light microscopy and scanning and transmission electron microscopy, molecular phylogenetic analyses of ribosomal RNA genes. Results We obtained the first data on fine morphology of aseptate eugregarines Polyrhabdina pygospionis and Polyrhabdina cf. spionis, the type species. We demonstrate that their AOs differ from the mucron in archigregarines and represent an epimerite structurally resembling that in other eugregarines examined using electron microscopy. We then used the concatenated ribosomal operon DNA sequences (SSU, 5.8S, and LSU rDNA) of P. pygospionis to explore the phylogeny of eugregarines with a resolution superior to SSU rDNA alone. The obtained phylogenies show that the Polyrhabdina clade represents an independent, deep-branching family in the Ancoroidea clade within eugregarines. Combined, these results lend strong support to the hypothesis that the epimerite is a synapomorphic innovation of eugregarines. Based on these findings, we resurrect the family Polyrhabdinidae Kamm, 1922 and erect and diagnose the family Trollidiidae fam. n. within the superfamily Ancoroidea Simdyanov et al., 2017. Additionally, we re-describe the characteristics of P. pygospionis, emend the diagnoses of the genus Polyrhabdina, the family Polyrhabdinidae, and the superfamily Ancoroidea.


1998 ◽  
Vol 353 (1375) ◽  
pp. 1553-1559 ◽  
Author(s):  
R. Araujo ◽  
M. A. Ramos

The glochidium of Margaritifera auricularia is described for the first time by using light microscopy, scanning electron microscopy and histological techniques. The larval mantle is formed by only two layers of cells; the inner one being much thicker, with microvilli. All cell masses of the glochidium are temporary aggregations that are the rudiments of organs of the subsequent juveniles which will be released after metamorphosis in the host tissues. In the glochidium there are three main masses of cells: (i) the muscle, which is in an anterior position; (ii) the oral plate in the centre of the larva; and (iii) the more ventrally and posteriorly situated ventral plate, or foot rudiment, flanged with lateral pits all bearing dense cilia. No rudimentary organs such as the pericardium, the kidney, the heart or nerve ganglia have developed. There are no visible hooks in the valve margins, but by using light microscopy we observed minute teeth covered by a rim of the periostracum. Near the margin of the shell there are two pairs of sensory hair tufts only observable by scanning electron microscopy. The glochidium of M. auricularia is the largest of the family Margaritiferidae and intermediate between the glochidium of the known species of this family and those of Unionidae.


Author(s):  
Maren Christensen ◽  
John S. Gardner ◽  
Phil S. Allen

The coleorhiza is a nonvascular sheath that encloses the embryonic radicle in Gramineae, and is generally the first tissue to emerge during germination. Coleorhiza cells develop extensions similar to root hairs, which are difficult to study quantitatively in situ because they are extremely sensitive to desiccation and breakage. Protective, absorptive and adhesive roles have been postulated for this tissue, but have received limited attention, This study used scanning electron microscopy (SEM) and light microscopy (LM) to characterize the coleorhiza and radicle during germination of Bromus tectorum, a species that often emerges from the soil surface in semiarid habitats.Caryopses (seeds) were imbibed at various water potentials over solutions of polyethylene glycol (PEG) or in soil until coleorhizae had emerged. For SEM, seeds imbibed over PEG were frozen in liquid freon and then freeze dried, Seeds imbibed in soil were frozen in liquid nitrogen and then freeze dried. For LM, seeds imbibed over PEG were subjected to freeze substitution in dry acetone with 1% OSO4 at -80°C for 19 days.


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