The Infection of Cells by Bullet-Shaped Viruses

Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

1965 ◽  
Vol 25 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Jack Maniloff ◽  
Harold J. Morowitz ◽  
Russell J. Barrnett

Thin-section electron microscopy, together with isolation of cellular organelles by differential centrifugation and chemical analysis, has been used to investigate the ultrastructure of the avian pleuropneumonia-like organism A5969. Each cell (approximate diameter 5500 A) was surrounded by a 150 A plasma membrane. In the center of the cell was an unbounded area, granular in appearance and containing the cell's DNA. The periphery of the cell contained granules of several different sizes and densities. The most dense particles (150 A) corresponded to the 78S ribosomes. These particles exhibited two predominant arrangements: (a) sometimes they showed cubic packing; (b) most arrays, however, were consistent with cylindrical arrangements of approximately 50 particles. Bundles of up to 18 arrays were observed. Structured blebs have been found protruding from the surface of log phase cells.


1985 ◽  
Vol 36 (3) ◽  
pp. 443 ◽  
Author(s):  
RM Harding ◽  
DS Teakle

The eggplant little-leaf agent was graft transmitted to tomato causing big-bud symptoms. Transmission from the big-bud tomato to potato by grafting or the leafhopper Orosius argentatus resulted in the development of purple top wilt symptoms. Thin-section electron microscopy revealed mycoplasma-like organisms present in the phloem sieve elements of a big-bud tomato plant and purple top wilt potato plants infected by grafting or leafhoppers. When tubers from graft-infected potato plants were planted, 73% produced spindly shoots and 44% of these later developed purple top wilt symptoms. When scions from either field-infected or experimentally infected potato plants showing purple top wilt symptoms were grafted onto tomato plants, 24% and 62% respectively developed big-bud symptoms. The results provide strong evidence for the mycoplasmal aetiology of some, if not all, potato purple top wilt in Queensland.


Nucleus ◽  
2014 ◽  
Vol 5 (6) ◽  
pp. 601-612 ◽  
Author(s):  
Vincent Duheron ◽  
Guillaume Chatel ◽  
Ursula Sauder ◽  
Vesna Oliveri ◽  
Birthe Fahrenkrog

1975 ◽  
Vol 61 (3) ◽  
pp. 476 ◽  
Author(s):  
Philip D. Lunger ◽  
Betty L. Rhoads ◽  
Ken Wolf ◽  
Maria E. Markiw

1979 ◽  
Vol 83 (2) ◽  
pp. 383-393 ◽  
Author(s):  
O Frederiksen ◽  
K Møllgård ◽  
J Rostgaard

The effects of mucosal application of 1 mg% Alcian blue (a trivalent cationic phthalocyanine dye) on functional and ultrastructural parameters of the isolated rabbit gallbladder have been studied. Apart from minor changes in the shape of the group of central microvilli observed in thin-section electron microscopy and scanning electron microscopy, the major ultrastructural change induced by Alcian blue was an almost complete collapse of intercellular spaces in the region above the tight junctions up to the bases of the marginal microvilli as revealed by thin-section electron microscopy. Freeze-fracture electron microscopy demonstrated a complete disappearance of intramembrane particles of neighboring cell membranes corresponding to the region of interspace collapse. Transepithelial electrical resistance (RT) increased from 44.5 to 58.7 ohm . cm2 upon treatment with Alcian blue. This increase could be well accounted for by the observed structural changes in the paracellular pathway if this pathway determines the low resistance of the rabbit gallbladder epithelium. Despite the increase in RT, net mucosa-to-serosa fluid transport and the spontaneous mucosa-positive potential difference of 3 mV were unaltered by Alcian blue treatment, supporting the hypothesis that the transepithelial transport mechanism per se is electroneutral. A calculation of the maximal paracellular mucosa-to-serosa waterflow in response to a lateral intercellular space hypertonicity of 20 mosM demonstrates that in the Alcian blue-treated gallbladder the resulting figure is about three orders of magnitude too low to keep up with the unaltered spontaneous transepithelial net fluid transport. It is therefore concluded that the tight junction pathway in rabbit gallbladders does not serve as a route for net fluid transport.


Sign in / Sign up

Export Citation Format

Share Document