The preservation of membranes of tubular bodies associated with mycoplasmalike organisms by tannic acid

1978 ◽  
Vol 56 (22) ◽  
pp. 2878-2882 ◽  
Author(s):  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Tannic Acid ◽  
Membrane Structure ◽  
Unit Membrane ◽  
Aster Yellows ◽  
Vinca Rosea ◽  
Common Unit ◽  
Hollow Cylinders ◽  
Tubular Body ◽  
Tubular Bodies ◽  
Mycoplasmalike Organisms

Fixation with a mixture of tannic acid and paraformaldehyde–glutaraldehyde resulted in an increased electron density of the membrane structure of tubular bodies that were associated with mycoplasma organisms (MLO) in Vinca rosea plants infected with the Alberta isolate of the aster yellows agent. The tubular bodies, 25.5 ± 4.3 nm in diameter, were bounded with membranes in contrast with the hollow cylinders of 12.3 ± 3.0 nm in conventional fixation. In the study of physical relationships, the tubular bodies were often connected with MLO by a common unit membrane. Some subtubules were formed from a main tubular body.

A YELLOWS-TYPE VIRUS OF ALSIKE CLOVER IN ALBERTA

1965 ◽  
Vol 43 (5) ◽  
pp. 527-536 ◽  
Author(s):  
L. N. Chiykowski
Keyword(s):  
Daucus Carota ◽  
Type Virus ◽  
Nicotiana Rustica ◽  
Aster Yellows ◽  
Daucus Carota L ◽  
Vinca Rosea ◽  
Clover Phyllody

A yellows-type virus was isolated from naturally infected alsike clover, Trifolium hybridum L., from Alberta by means of the six-spotted leafhopper, Macrosteles fascifrons (Stål), and transmitted to T. hybridum, Callistephus chinensis Nees, Vinca rosea L., Daucus carota L., and Nicotiana rustica L. Attempts to isolate the virus with Scaphytopius acutus (Say) were unsuccessful. On the basis of symptomatology and vector–virus relationships it is concluded that this virus is distinct from the clover phyllody virus and known strains of the aster yellows virus. The name, clover proliferation virus, is proposed. Symptoms produced on hosts are illustrated and discussed.

Fine structure of sensilla on the ovipositor of the tephritid fly Urophora affinis

1986 ◽  
Vol 64 (4) ◽  
pp. 973-984 ◽  
Author(s):  
R. Y. Zacharuk ◽  
R. M. K. W. Lee ◽  
D. E. Berube
Keyword(s):  
Fine Structure ◽  
Epidermal Cell ◽  
Fruit Flies ◽  
Sheath Cell ◽  
Outer Sheath ◽  
Dendritic Segment ◽  
Tubular Body ◽  
Tubular Bodies ◽  
Sheath Cells

There are four types of sensilla on the ovipositor blade of Urophora affinis Frauenfeld, one more than was observed on three other species of fruit flies studied by other authors. Three of the types, uniporous gustatory pegs, campaniform organs, and tactile short hairs are common to the four species and generally are in similar positions on the blade. The fourth, uniporous gustatory plates, were noted in U. affinis only. The chemosensilla are innervated by three chemosensory dendrites that terminate below the pore and a mechanosensory dendrite with a tubular body that is attached to a basal cuticular apodeme of the covering cuticle. The dendritic tubular bodies of the campaniform organs and tactile hairs terminate parallel to the surface in a right-angular bend, where they are attached to basal apodemes of the covering cuticle. The chemosensilla and tactile hairs have individual outer and inner sheath cells, but the campaniform organs have individual inner sheath cells only. The part of the ciliary dendritic segment that is encased by the dendritic sheath passes through an epidermal cell, often with several sensilla sharing the same epidermal cell in place of an outer sheath cell. The role of these sensilla during oviposition is discussed.

The formation and function of the extraacrosomal layer and modification of the plasma membrane in spermiogenesis of Acrida lata motschulsky (Orthoptera)

1978 ◽  
Vol 36 (2) ◽  
pp. 570-571
Author(s):  
Gonpachiro Yasuzumi ◽  
Toshikatsu Asai
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Cell Surface ◽  
Membrane Structure ◽  
Early Stage ◽  
Cell Types ◽  
Unit Membrane ◽  
Sharp Point ◽  
Specific Proteins ◽  
And Function

Receptor-specific proteins are now being widely and usefully applied to the study of cell-surface topography. We have been actively interested in this field from the standpoint of spermiogenesis of the grasshopper. The surface of developing spermatids is in contact with other cells or with their environment, and in addition to carrying on metabolic processes necessary for maturation they must also exhibit the specificity that distinguishes cells from the same cell types from different individuales. The cell bodies of the grasshopper, Acrida lata Motschulsky, spermatids are spherical in the early stage of metamorphosis, but later they become conical and more and more elongate until they are long slender rods, rounded at the base and tapering at the tip to a sharp point. Concurrently with these changes in the spermatid cell bodies, the remarkable trans formation occurs in the fine structure of the cell-surface. In the early stage of maturation of spermatids, the cell-surface is smooth and consists of the unit membrane structure.

Vesicles and Granules in the Retina of a Snail, Helix Aspersa

1967 ◽  
Vol 25 ◽  
pp. 212-213
Author(s):  
Richard M. Eakin ◽  
Jean L. Brandenburger
Keyword(s):  
Membrane Structure ◽  
Sensory Cells ◽  
High Magnification ◽  
Total Thickness ◽  
Unit Membrane ◽  
En Face ◽  
Cross Bridges ◽  
Snail Helix Aspersa ◽  
Spherical Vesicles ◽  
Electron Lucent

Sensory cells in the eyes of pulmonate snails possess extraordinary perinuclear masses of spherical vesicles, each about 800 A in diameter. They typically exhibit a paracxrystalline arrangement. The same pattern is found also in sensory cells of eyes that had completely regenerated following removal of the tip of the tentacle and the original eye several months earlier (Fig. 1). High magnification (Fig. 2) shows that the vesicles are bounded by a single membrane. In sections normal to the surface of the vesicle the inner and outer leaflets appear to have about the same thickness (20 A). The electron lucent space between the osmiophilic layers is approximately 30 A wide, making the total thickness of the membrane about 70 A. The membrane appears to be particulate in both sectional and en face views of vesicles fixed in glutaraldehyde and postfixed in OsO4. And there is a suggestion of cross bridges (arrows) between the two leaflets. The picture resembles that found by various investigators, Sjöstrand for example, in other membranes. Such images have been interpreted as indicating a globular or micellar organization of the membrane rather than a trilaminar (unit membrane) structure. Interpretation is difficult considering the possibility of image overlap artifact in viewing sections through the curved surface of a small vesicle. Faint irregular densities may be seen within the vesicles.

SCAPHYTOPIUS ACUTUS (SAY), A NEWLY DISCOVERED VECTOR OF CELERY-INFECTING ASTER-YELLOWS VIRUS

1962 ◽  
Vol 40 (6) ◽  
pp. 799-801 ◽  
Author(s):  
L. N. Chiykowski
Keyword(s):  
Incubation Period ◽  
Incubation Time ◽  
Trifolium Repens ◽  
Feeding Period ◽  
Aster Yellows ◽  
Vinca Rosea ◽  
Trifolium Repens L ◽  
Test Plants

Scaphytopius acutus (Say) transmitted a celery-infecting strain of aster-yellows virus from infected periwinkle (Vinca rosea L.) and aster (Callistephus chinensis Nees) to periwinkle, aster, and ladino clover (Trifolium repens L.). It acquired the virus during feeds as short as 4 hours, and transmitted it during a 2-hour feeding period. The minimum incubation time for the virus in the insect was between 21 and 26 days. After an acquisition feed of 7 days and an incubation period of at least 30 days, 11 of 21 insects transmitted the virus to separate periwinkle test plants.

Banded filaments associated with the aster yellows MLO in Vinca rosea L.

1978 ◽  
Vol 24 (11) ◽  
pp. 1417-1418 ◽  
Author(s):  
D. E. Carling ◽  
D. F. Millikan
Keyword(s):  
Aster Yellows ◽  
Characteristic Morphology ◽  
Vinca Rosea ◽  
Electron Lucent

The ultrastructure of an aster yellows mycoplasma-like organism was studied in the phloem of periwinkle (Vinca rosea L.) plants. Banded filaments were observed in association with mycoplasma-like organisms of characteristic morphology. The filaments were variable in length, from 50–100 nm in width, and displayed a regular periodic banding of alternating electron-dense and electron-lucent structures.

The Structure of Tight Junctions

1978 ◽  
Vol 36 (3) ◽  
pp. 659-672 ◽  
Author(s):  
S. Bullivant
Keyword(s):  
Tight Junction ◽  
Intercellular Space ◽  
Membrane Structure ◽  
Paracellular Permeability ◽  
Apical Region ◽  
Unit Membrane ◽  
Thin Sections ◽  
Freeze Fracturing ◽  
Outer Leaflet ◽  
Zonula Occludens

The tight junction, or zonula occludens, is generally found as a continuous belt, joining adjacent cells in the apical region of the border between them. It forms a seal across the intercellular space and hence regulates paracellular permeability. Farquhar and Palade (1963), recognised the belt-like sealing character, and showed that in thin sections the junction was seen as either punctate or linear fusions of the two membranes, often with the loss of the outer leaflet of the unit membrane at the fusion. With thin sections it can only be inferred that the junction forms a continuous belt, but with freeze-fracturing it can be seen directly. Moreover, in the junctional region the membrane structure is modified by a series of interconnected fibrils approximately parallel to the line of the belt (Kreutziger, 1968; Staehelin et al, 1969; Goodenough and Revel, 1970), and within the interior of the membrane Tchalcroft and Bullivant, 1970). The fibrils are at the lines of membrane fusion.

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