Freeze-fracture analysis of the effects of age and 2,4-dinitrophenol on the morphology of flight muscle mitochondria of Musca Domestica L.

1981 ◽  
Vol 16 (2) ◽  
pp. 191-204 ◽  
Author(s):  
Angelo Turturro ◽  
Saiyid A. Shafiq
Keyword(s):  
Musca Domestica ◽  
Flight Muscle ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Muscle Mitochondria

Topographical variations in the structure of the smooth septate junction

1979 ◽  
Vol 37 (1) ◽  
pp. 373-389
Author(s):  
H.B. Skaer ◽  
J.B. Harrison ◽  
W.M. Lee
Keyword(s):  
Musca Domestica ◽  
Functional Significance ◽  
Freeze Fracture ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Septate Junction ◽  
Lanthanum Hydroxide ◽  
Septate Junctions ◽  
Standard Fixation

Smooth septate junctions in the midgut of Musca domestica and in Malpighian tubules of both Musca and Rhodnius prolixus are described. Details of the structures revealed after standard fixation, fixation in the presence of the stain, lanthanum hydroxide, and after freeze-fracture are discussed in the light of models previously put forward to explain the interrelations of the images obtained by these different methods. The organization of the junction between cells of the midgut varies in the apical-to-basal axis. At the apical border the septa (or ridges in freeze-fracture replicas) are packed tightly and follow an undulating but strictly parallel course. This packing loosens towards the middle of the junction until, at its basal extremity, the septa (ridges in replicas) are widely separated and follow independent meandering courses. That these features are found both in lanthanum-infiltrated specimens and freeze-fracture replicas allows a correlation to be made between the septa and the freeze-fracture ridges. The functional significance of these smooth septate junctions is discussed.

Freeze-fracture analysis of membrane events during early neogenesis of cilia in Tetrahymena: changes in fairy-ring morphology and membrane topography

1983 ◽  
Vol 60 (1) ◽  
pp. 137-156
Author(s):  
L.A. Hufnagel
Keyword(s):  
Cell Division ◽  
Membrane Structure ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Basal Bodies ◽  
Membrane Topography ◽  
Fairy Rings ◽  
Dividing Cells ◽  
Cortical System ◽  
Membrane Particle

A freeze-fracture analysis of early neogenesis of somatic and oral cilia of Tetrahymena was conducted using exponentially grown cultures and also cells induced to undergo oral reorganization. In this report, presumptive ciliary domains (PCDs), sites of future outgrowth of somatic cilia, are identified and their membrane structure is described in detail. The fairy ring, an array of membrane particles that occurs within the PCD and appears to be a precursor of the ciliary necklace, is described. A sequence of early stages in the formation of the ciliary necklace of somatic cilia is deduced from topographical information and membrane particle arrangements and numbers. Evidence is presented that basal bodies are seated at the cell surface prior to initiation of necklace assembly and a possible role for the basal body in necklace assembly is suggested. In dividing cells, new oral cilia grow out prior to orientation of cilia-parasomal sac complexes relative to cell axes. In dividing cells and during oral reorganization, new cilia also develop prior to their alignment into membranelles. Thus, growth of cilia is independent of their spatial orientation. Fairy rings were not observed during oral reorganization. During cell division, proliferation of new cilia is accompanied by the formation of a network of junctions between a cortical system of membranous cisternae, the cortical ‘alveoli’. These interalveolar junctions may serve as tracks for early positioning and orientation of new oral basal bodies.

scholarly journals The effect of the coupled oxidation of substrate on the permeability of blowfly flight-muscle mitochondria to potassium and other cations

1972 ◽  
Vol 126 (3) ◽  
pp. 689-700 ◽  
Author(s):  
R. G. Hansford ◽  
A. L. Lehninger
Keyword(s):  
Light Scattering ◽  
Flight Muscle ◽  
Unit Area ◽  
Membrane Surface ◽  
Mitochondrial Matrix ◽  
Exposed Area ◽  
Muscle Mitochondria ◽  
Area 5 ◽  
Choline Phosphate ◽  
Permeant Anion

1. Blowfly flight-muscle mitochondria respiring in the absence of phosphate acceptor (i.e. in state 4) take up greater amounts of K+, Na+, choline, phosphate and Cl-(but less NH4+) than non-respiring control mitochondria. 2. Uptake of cations is accompanied by an increase in the volume of the mitochondrial matrix, determined with the use of [14C]-sucrose and3H2O. The osmolarity of the salt solution taken up was approximately that of the suspending medium. 3. The [14C]sucrose-inaccessible space decreased with increasing osmolarity of potassium chloride in the suspending medium, confirming that the blowfly mitochondrion behaves as an osmometer. 4. Light-scattering studies showed that both respiratory substrate and a permeant anion such as phosphate or acetate are required for rapid and massive entry of K+, which occurs in an electrophoretic process rather than in exchange for H+. The increase in permeability to K+and other cations is probably the result of a large increase in the exposed area of inner membrane surface in these mitochondria, with no intrinsic increase in the permeability per unit area. 5. No increase in permeability to K+and other cations occurs during phosphorylation of ADP in state 3 respiration.

Freeze–fracture analysis of muscle plasma membrane in Becker's muscular dystrophy

1994 ◽  
Vol 20 (5) ◽  
pp. 487-494 ◽  
Author(s):  
S. Shibuya ◽  
Y. Wakayama ◽  
T. Jimi ◽  
H. Oniki ◽  
T. Kobayashi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Muscular Dystrophy ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Muscle Plasma Membrane

scholarly journals Freeze-fracture analysis of the membrane lesion of human complement.

1983 ◽  
Vol 97 (3) ◽  
pp. 618-626 ◽  
Author(s):  
J Tranum-Jensen ◽  
S Bhakdi
Keyword(s):  
Transmembrane Protein ◽  
Freeze Fracture ◽  
Fracture Analysis ◽  
Membrane Insertion ◽  
Membrane Bilayer ◽  
Face Ring ◽  
Circular Structure ◽  
Protein Channel ◽  
Classical Ring ◽  
Membrane Lesion

The structure and membrane insertion of the human C5b-9(m) complex, generated by lysis of antibody-coated sheep erythrocytes with whole human serum under conditions where high numbers of classical ring-shaped lesions form, were studied in single and complementary freeze-fracture replicas prepared by unidirectional and rotary shadowing. The intramembrane portion of the C5b-9(m) cylinder was seen on EF-faces as an elevated, circular structure. In nonetched fractures it appeared as a solid stub; in etched fractures a central pit confirmed the existence of a central, water-filled pore in the molecule. Complementary replicas showed that each EF-face ring corresponded to a hole in the lipid plateau of the PF-face. Etched fractures of proteolytically stripped membranes revealed the extramembrane annulus of the C5b-9(m) cylinder on ES-faces and putative internal openings on PS-faces. Allowing for the measured thickness of deposited Pt/C, the dimensions of EF-face rings and ES-face annuli conformed to anticipations derived from negatively stained preparations. Our results support the concept that the hollow cylindrical C5b-9(m) complex penetrates into the inner leaflet of the target erythrocyte membrane bilayer, forming a stable transmembrane protein channel.

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