The Tegument and Associated Structures of Fasciola Hepatica

1963 ◽  
Vol s3-104 (68) ◽  
pp. 505-512
Author(s):  
L. T. THREADGOLD
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Light Microscopy ◽  
Fasciola Hepatica ◽  
Golgi Bodies ◽  
New Knowledge ◽  
Pinocytotic Vesicles ◽  
The Individual ◽  
And Function ◽  
Internal Level

The cuticle of light microscopy is shown by electron microscopy to be a surface layer of protoplasm which is an extension of areas of nucleated protoplasm lying deep in the parenchyma. The cuticle therefore exists at two levels. The external level is syncytial, consisting of plateaux separated by branching valleys. This level contains apical pinocytotic vesicles, numerous mitochondria, endoplasmic membranes, large basal and other vacuoles, and dense spines. Tube-like evaginations from the base of the external level connect it to the individual areas of flask-shaped protoplasm which compose the internal level. Each of these areas of protoplasm contains a nucleus, great numbers of mitochondria, some vacuoles and diffuse inclusions, and the Golgi bodies. The histochemistry and function of the cuticle is discussed in the light of this new knowledge of cuticular ultrastructure, and a comparison is made between the cuticle of Cestoda and Trematoda.

Taxonomic application of macro and micro morphological characters of seeds in Astragalus L. (Galegeae, Fabaceae) in India

Phytotaxa ◽  
2021 ◽  
Vol 502 (2) ◽  
pp. 191-207
Author(s):  
SHIVANI KASHYAP ◽  
CHANDAN KUMAR SAHU ◽  
ROHIT KUMAR VERMA ◽  
LAL BABU CHAUDHARY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Seed Coat ◽  
Morphological Plasticity ◽  
Morphological Characters ◽  
Individual Species ◽  
Large Size ◽  
The Individual ◽  
Scanning Electron

Due to large size and enormous morphological plasticity, the taxonomy of the genus Astragalus is very complex and challenging. The identification and grouping of species chiefly based on macromorphological characters become sometimes difficult in the genus. In the present study, the micromorphology of the seeds of 30 species belonging to 14 sections of Astragalus from India has been examined applying scanning electron microscopy (SEM) along with light microscopy (LM) to evaluate their role in identification and classification. Attention was paid to colour, shape, size and surface of seeds. The overall size of the seeds ranges from 1.5–3.2 × 0.8–2.2 mm. The shape of the seeds is cordiform, deltoid, mitiform, orbicular, ovoid and reniform. The colour of seeds varies from brown to blackish-brown to black. Papillose, reticulate, ribbed, rugulate and stellate patterns were observed on the seed coat surface (spermoderm) among different species. The study reveals that the seed coat ornamentations have evolved differently among species and do not support the subgeneric and sectional divisions of the genus. However, they add an additional feature to the individual species, which may help in identification in combination with other macro-morphological features.

Immunoprobe Localization by Correlative Microscopy

2000 ◽  
Vol 6 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Patricia G. Calarco
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Ultrastructural Level ◽  
Correlative Microscopy ◽  
Microtubule Organizing Center ◽  
Large Size ◽  
Organizing Center ◽  
Gamma Tubulin ◽  
High Level ◽  
And Function

AbstractMammalian oocytes present challenges for optimal study by electron microscopy (EM) due to their high level of hydration, their large size, and their relatively undifferentiated cytoplasm. This is particularly true for immunoprobe localization which has led to a dependence on light microscopic (LM) techniques, such as immunofluorescence. This study presents correlative LM and EM data to describe an example of the failure of light microscopy to correctly predict the ultrastructure of one particular organelle. Immunoprobe localization of centrosome and microtubule organizing center (MTOC) antigens in the mammalian egg was made by immunofluorescence and post-embedding immuno-EM, with best EM results achieved in Lowicryl-embedded material. Centrosome and MTOC antigens were detected by 5051 and an antibody to gamma tubulin (γtubulin). Gamma tubulin is a highly conserved element of MTOCs in many species and, thus, is highly diagnostic for them; it is also considered essential for microtubule (MT) nucleation. Results indicate that prior to nuclear breakdown, 5051 antigens and γ-tubulin are found exclusively in a type of “organelle,” the multivesicular aggregate (MVA), that bears no resemblance to MTOCs at the ultrastructural level. Until recently, the MVA was considered an organelle without a known function, while standard MTOCs were presumed to be the entities that carry the proteins recognized by centrosome antibodies. LM localization of centrosomal antigens carried the presumption that standard MTOCs were the entities labeled. Whether or not other molecules are shown to co-localize to these MVA, the presence of γ-tubulin supports the contention that MVA, or their contents, serve as centrosomal precursors with a unique ultrastructure. Thus, dependence on LM techniques alone can lead to erroneous conclusions on organelle identity and function.

A theory of translocation in phloem of Heracleum by contractile protein microfibrillar material

1972 ◽  
Vol 50 (3) ◽  
pp. 479-497 ◽  
Author(s):  
D. S. Fensom
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Light Microscopy ◽  
Mass Flow ◽  
Sieve Tube ◽  
Flow Mode ◽  
Sucrose Transport ◽  
Small Surface ◽  
Callose Formation ◽  
Mode A

Recent findings based on light microscopy, electron microscopy, electrical gradients, microinjection, and tracer feeding, all on isolated but living phloem strands of Heracleum are here summarized and collated. A new theory of translocation is presented in which sucrose transport occurs in two chief modes. The first is based on microperistaltic movement of contractile lipoprotein which is thought to extend axially through the sieve tube. The second is a mass flow of solution around the contractile microfibrillar material, but chiefly activated by it. The microfibrillar material transports sucrose in pulses at about 400 cm h−1 and this mode of translocation is stopped by cold blocks and desiccation, but not by callose. The mass flow mode is slower and is stopped by callose formation and also by the cessation of activity of the microfibrillar or pulsing mode. A third small surface-layer component of translocation is also indicated, operating at speeds above 1000 cm h−1.

scholarly journals Histological Variation in Plethodontid Digital Surfaces [University of Findlay]

2019 ◽  
Author(s):  
Megan Pasternak ◽  
Justin Rheubert
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Morphology ◽  
Light Microscopy ◽  
Morphological Evolution ◽  
Ventral Surface ◽  
Cellular Level ◽  
Plethodontid Salamanders ◽  
And Function ◽  
Scanning Electron

Despite numerous investigations into the morphology and function of toe pads in many species, most notably anurans and geckonids, there is relatively little knowledge on salamander digit morphology. To date, toe morphology in salamanders has been limited to Desmognathus fuscus, Ambystoma maculatum, Bolitoglossa sp., and Aneides aeneus. The limited studies to date have shown variation inter- and intra-specifically but have not investigated numerous taxa within a given family which may provide deeper insights into the causes of variation (phylogenetic vs ecological pressures). Therefore, to test hypotheses concerning the presence of variation in the ventral digital surface of plethodontid salamanders, we plan to use various microscopy methodologies to view the ventral surface of the digital tips of three species from three different genera within the Plethodontidae: Desmognathus, Eurycea, and Plethodon. Toe pads will be characterized grossly using scanning electron microscopy, histologically using light microscopy, and ultrastructurally using transmission electron microscopy. Preliminary results suggest that all three species investigated display enlarged surfaces. Surface morphology (assessed via scanning electron microscopy) varies between species at a gross level concerning the shape and overall orientation of the enlarged surface. Surface morphologies include a well-developed circular pad (D. fuscus), a well-developed oval pad (P. cinereus), and a poorly developed circular pad (E. cirrigera). Furthermore, surface morphology appears to vary at the cellular level as well, with Desmognathus having polygonal squamous cells with microprojections and Eurycea having polygonal cells with nanopillars in a honeycomb arrangement. These differences may be attributed to differences in habitat preference as the three species tested include a terrestrial, semi-aquatic, and aquatic dwelling species. However, further investigation including light microscopy and enhanced scanning electron microscopy are needed. Further understanding of the morphological variation will aid in our understanding of ecomorphology and understanding of morphological evolution in amphibians.

Immunoprobe Localization by Correlative Microscopy

2000 ◽  
Vol 6 (3) ◽  
pp. 195-201
Author(s):  
Patricia G. Calarco
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Ultrastructural Level ◽  
Correlative Microscopy ◽  
Microtubule Organizing Center ◽  
Large Size ◽  
Organizing Center ◽  
Gamma Tubulin ◽  
High Level ◽  
And Function

Abstract Mammalian oocytes present challenges for optimal study by electron microscopy (EM) due to their high level of hydration, their large size, and their relatively undifferentiated cytoplasm. This is particularly true for immunoprobe localization which has led to a dependence on light microscopic (LM) techniques, such as immunofluorescence. This study presents correlative LM and EM data to describe an example of the failure of light microscopy to correctly predict the ultrastructure of one particular organelle. Immunoprobe localization of centrosome and microtubule organizing center (MTOC) antigens in the mammalian egg was made by immunofluorescence and post-embedding immuno-EM, with best EM results achieved in Lowicryl-embedded material. Centrosome and MTOC antigens were detected by 5051 and an antibody to gamma tubulin (γtubulin). Gamma tubulin is a highly conserved element of MTOCs in many species and, thus, is highly diagnostic for them; it is also considered essential for microtubule (MT) nucleation. Results indicate that prior to nuclear breakdown, 5051 antigens and γ-tubulin are found exclusively in a type of “organelle,” the multivesicular aggregate (MVA), that bears no resemblance to MTOCs at the ultrastructural level. Until recently, the MVA was considered an organelle without a known function, while standard MTOCs were presumed to be the entities that carry the proteins recognized by centrosome antibodies. LM localization of centrosomal antigens carried the presumption that standard MTOCs were the entities labeled. Whether or not other molecules are shown to co-localize to these MVA, the presence of γ-tubulin supports the contention that MVA, or their contents, serve as centrosomal precursors with a unique ultrastructure. Thus, dependence on LM techniques alone can lead to erroneous conclusions on organelle identity and function.

scholarly journals Evidence from the resurrected family Polyrhabdinidae Kamm, 1922 (Apicomplexa: Gregarinomorpha) supports the epimerite, an attachment organelle, as a major eugregarine innovation

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11912
Author(s):  
Gita G. Paskerova ◽  
Tatiana S. Miroliubova ◽  
Andrea Valigurová ◽  
Jan Janouškovec ◽  
Magdaléna Kováčiková ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Dna Sequences ◽  
Phylogenetic Analyses ◽  
Strong Support ◽  
Molecular Data ◽  
Lsu Rdna ◽  
The Family ◽  
Molecular Phylogenetic ◽  
And Function

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.

Advances in Correlative Single-Molecule Localization Microscopy and Electron Microscopy

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Ulrike Endesfelder
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Single Molecule ◽  
Light And Electron Microscopy ◽  
Fluorescence Labeling ◽  
Localization Microscopy ◽  
Fluorescence Light Microscopy ◽  
Fluorescence Light ◽  
And Function ◽  
Single Molecule Localization Microscopy

AbstractDuring the last few decades, correlative fluorescence light and electron microscopy (FLM-EM) has gained increased interest in the life sciences concomitant with the advent of fluorescence light microscopy. It has become, accompanied by numerous developments in both techniques, an important tool to study bio-cellular structure and function as it combines the specificity of fluorescence labeling with the high structural resolution and cellular context information given by the EM images. Having the recently introduced single-molecule localization microscopy techniques (SMLM) at hand, FLM-EM can now make use of improved fluorescence light microscopy resolution, single-molecule sensitivity and quantification strategies. Here, currently used methods for correlative SMLM and EM including the special requirements in sample preparation and imaging routines are summarized and an outlook on remaining challenges concerning methods and instrumentation is provided.

Light and electron microscope studies of cytoplasmic aggregates formed in barley cells in response to Erysiphe graminis

1976 ◽  
Vol 54 (14) ◽  
pp. 1647-1655 ◽  
Author(s):  
W. R. Bushnell ◽  
R. J. Zeyen
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Rough Endoplasmic Reticulum ◽  
Rapid Development ◽  
Epidermal Cells ◽  
Erysiphe Graminis ◽  
Synthetic Activity ◽  
Golgi Bodies

Cytoplasmic aggregates that formed in susceptible barley epidermal cells 11-12 h after inoculation with Erysiphe graminis were examined by light microscopy in living specimens and by electron microscopy in fixed specimens. Rapid development of the aggregate (5–10 min) suggested that cytoplasm migrated to the site of each aggregation. The aggregate contained features generally associated with areas of high metabolic and synthetic activity: abundant mitochondria, rough endoplasmic reticulum (associated with smooth cisternae), Golgi bodies, and polyribosomes. Leucoplasts and nuclei were sometimes near aggregates but not consistently. Microbodies and osmiophilic spherosomes were not present.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Tumor Diagnosis

1982 ◽  
Vol 40 ◽  
pp. 262-265
Author(s):  
Bruce Mackay
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Diagnosis ◽  
Light Microscopy ◽  
Clinical Examination ◽  
Ultrastructural Study ◽  
Diagnostic Procedures ◽  
Specific Diagnosis ◽  
Transmission Electron ◽  
Microscopic Diagnosis

The broadest application of transmission electron microscopy (EM) in diagnostic medicine is the identification of tumors that cannot be classified by routine light microscopy. EM is useful in the evaluation of approximately 10% of human neoplasms, but the extent of its contribution varies considerably. It may provide a specific diagnosis that can not be reached by other means, but in contrast, the information obtained from ultrastructural study of some 10% of tumors does not significantly add to that available from light microscopy. Most cases fall somewhere between these two extremes: EM may correct a light microscopic diagnosis, or serve to narrow a differential diagnosis by excluding some of the possibilities considered by light microscopy. It is particularly important to correlate the EM findings with data from light microscopy, clinical examination, and other diagnostic procedures.

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