scholarly journals The Effect of Prolactin on the Number of Membrane-Associated Particles in Kidney Cells of the Euryhaline Teleost Gasterosteus Aculeatus during Transfer from Seawater to Freshwater: A Freeze-Etch Study

1974 ◽  
Vol 16 (3) ◽  
pp. 687-701
Author(s):  
S. E. WENDELAAR BONGA ◽  
M. VEENHUIS
Keyword(s):  
Gasterosteus Aculeatus ◽  
Hormonal Control ◽  
Outer Cell ◽  
Kidney Cells ◽  
Rate Of Increase ◽  
Basal Labyrinth ◽  
Euryhaline Teleost ◽  
Ovine Prolactin ◽  
Enzyme Complexes ◽  
Number Of Particles

The membranes of kidney cells of 3-spined sticklebacks were examined in freeze-etch replicas. The numbers of particles adhering to surfaces and fracture faces of the outer cell membranes and the membranes of the basal labyrinth were determined. The latter membranes probably are the main location of ion-transporting enzyme complexes. The total number of particles per cell in freshwater fish exceeds that of seawater fish by about 50 % for the outer cell membrane, and by almost 200 % for the membranes of the basal labyrinth. After transfer of seawater fish to freshwater, particle numbers increase and their densities approximate freshwater values after 20 h. This rise in particle numbers coincides with the increase of ion-transporting activity of the cells known to take place after transfer to freshwater. The rate of increase of particle densities is enhanced after injection of ovine prolactin. This hormone is known to stimulate Na+/K+-ATPase activity of the basal labyrinth of teleost kidney cells. The results indicate that the particles represent enzyme complexes. The number of particles is probably under hormonal control. The increase in particle densities after transfer to freshwater is accompanied by a rise in the number of nuclear pores, which is noticeable by 10 h. No changes were observed in the density of the particles adhering to the fracture faces of gap junctions.

scholarly journals The Membranes of the Basal Labyrinth in Kidney Cells of the Stickleback, Gasterosteus Aculeatus, Studied in Ultrathin Sections and Freeze-Etch Replicas

1974 ◽  
Vol 14 (3) ◽  
pp. 587-609
Author(s):  
S. E. WENDELAARBONGA ◽  
M. VEENHUIS
Keyword(s):  
Membrane Structure ◽  
Osmium Tetroxide ◽  
Cell Membranes ◽  
Gasterosteus Aculeatus ◽  
Outer Cell ◽  
Kidney Cells ◽  
Thin Sections ◽  
Protein Model ◽  
Basal Labyrinth ◽  
Ultrathin Sections

The structure of the basal labyrinth in kidney cells of freshwater sticklebacks was studied in ultrathin sections (after fixation with permanganate, osmium tetroxide, and combinations of glutaraldehyde with osmium tetroxide) and in freeze-etch replicas (after pretreatment with glutaraldehyde and/or glycerol, or without pretreatment). The structure of the basal labyrinth in sticklebacks, and probably in other teleost species, differs essentially from the type of labyrinth found in kidney cells of mammals like the rat. In the latter animals, the space enclosed by the membranes of the labyrinth is intercellular. In the stickleback the labyrinth consists of an intracellular system of branched membranes lining narrow saccular spaces. These spaces communicate with the exterior of the cells by means of small pores, located in the lateral and basal parts of the outer cell membranes. All chemical fixation procedures used introduced specific structural artifacts. It is concluded that the structure of the basal labyrinth is relatively well preserved after fixation with potassium permanganate, with a mixture of glutaraldehyde and osmium tetroxide, or with osmium tetroxide when applied for 10 min only. The unit-membrane structure was, however, absent after all procedures involving osmium tetroxide. In freeze-etch replicas determinations were made of the numbers of small particles covering the surfaces and fracture faces of the membranes of the basal labyrinth and of the outer cell membranes. The numbers per unit area of surface proved to be markedly constant and specific for each of the four faces of both types of membranes. Specific differences were found between the particle densities of the outer cell membranes and the membranes of the basal labyrinth. This finding points to functional differences between these types of membranes. Particle densities were not influenced by pre-incubation with glycerol. After fixation with glutaraldehyde, the particles adhering to the outer and inner surfaces had decreased in number. It is concluded from this study that membrane structure, as revealed in thin sections as well as in freeze-etch replicas, is consistent with Singer's ‘fluid lipid-crystal protein’ model.

The Occurrence of “A,” “C” and “Spoked” Virus Particles in Hamster Tumors

1971 ◽  
Vol 29 ◽  
pp. 370-371
Author(s):  
H. Saito ◽  
B. G. Uzman
Keyword(s):  
Tumor Cells ◽  
Human Tumor ◽  
Outer Diameter ◽  
Kidney Cells ◽  
Human Tumor Cells ◽  
Virus Particles ◽  
Type C ◽  
Murine Leukemia ◽  
Baby Hamster Kidney Cells ◽  
Number Of Particles

Several passages of five different hamster tumor lines were surveyed by electron microscopy for the presence of virus particles. Four of these tumors originated and were serially transplanted in adult Syrian hamsters. One line was derived by implantation of cultured baby hamster kidney cells. In all 5 tumor lines examined, “spoked virus” particles, first described by Bernhard and Tournier, were observed. These particles (Fig. 1) have an outer diameter of 90-110 mµ with a central nucleoid of 40-50 mµ and are always found in cisternae of rough endoplasmic reticulum or within the outer nuclear envelope. They are easily distinguishable from the murine leukemia type C particles by the presence of characteristic electron-dense radial structures which emanate from the nucleoid. In the cell line which has been most extensively studied (H-Sul-1-SC), the number of particles per cell appeared to increase in later passages of the tumor. Tumor cells from this line were grown in culture and were found to carry the same particles. While the “spoked virus” has been found by many investigators in a variety of neoplastic hamster cells, it has not been observed in this laboratory in an extensive survey of human tumor cells serially transplanted in newborn hamsters.

scholarly journals ON THE REPRODUCTION OF INFLUENZA VIRUS

1954 ◽  
Vol 100 (2) ◽  
pp. 135-161 ◽  
Author(s):  
Frank L. Horsfall
Keyword(s):  
Half Life ◽  
Influenza A ◽  
Allantoic Fluid ◽  
Reproductive Process ◽  
Rate Of Increase ◽  
The Difference ◽  
Almost All ◽  
Number Of Particles

Procedures which make possible the enumeration of both infective and hemagglutinating influenza A virus particles have been developed and used in a quantitative investigation on the reproduction of the agent. Infective particles were found to be highly unstable and their half-life was only 147 minutes in allantoic fluid at 35°C. both in vitro and in vivo. The instability of infective particles provides an explanation for the rapid accumulation of non-infective particles which retained the hemagglutinating property. The number of non-infective (N) particles was determined from the difference between the number of hemagglutinating (H) particles and the number of infective (I) particles as indicated by the relation: [N] = [H]– [1]. When the half-life of infective particles was taken into account, both infective and hemagglutinating particles were found to disappear from the allantoic fluid; i.e., were adsorbed by the allantoic membrane, at the same logarithmic rate after inoculation. Inoculation of any number of particles up to 3 x 107 was followed by a constant and progressive decrease in the proportion of unadsorbed particles from 0 to 4 hours. Approximately 20 per cent of particles were unadsorbed at 2 hours and about 5 per cent at 4 hours. Inoculation of 3 x 108 or more particles led to a larger proportion of unadsorbed particles at 4 hours. The maximum number of particles adsorbed was computed to be about 1.6 x 109. The concentration of both infective and hemagglutinating particles increased rapidly in the allantoic fluid after 4 hours when any number of infective particles up to 3 x 107 was inoculated. With such inocula, the rate of increase during the logarithmic period was constant and the time to double the concentration of infective or hemagglutinating particles was 46 minutes. With larger inocula, i.e. 3 x 108 particles, the concentrations of infective and hemagglutinating particles did not increase until after 8 hours and the rate of increase was much slower. The time to double the concentration of either then became 92 minutes. The number of infective particles was approximately equal to the number of hemagglutinating particles during the logarithmic increase period when any number of infective particles up to 3 x 106 was inoculated and no more than 106 non-infective particles were included in the inoculum. This finding was taken to indicate that all or almost all particles produced and released under these conditions were infective. That such particles became inactivated rapidly and led to the accumulation of an increasing number of non-infective particles after the logarithmic period can be explained by the short half-life of infective particles. The number of infective particles was no larger than one-tenth the number of hemagglutinating particles during the logarithmic increase period after 3 x 107 or more infective particles had been inoculated or when smaller inocula were used which also contained 3 x 107 or more non-infective particles. Non-infective particles prepared in vitro at 35° or 22°C. were as effective as those which accumulated in vivo in diminishing the proportion of infective particles in the yield. The extent of the reduction in the proportion of infective particles was directly related to the number of non-infective particles included in the inoculum. The yield of hemagglutinating particles was diminished when the inoculum contained 3 x 107 or more non-infective particles. The rate of increase was reduced so that the time to double the concentration became 92 minutes when the inoculum contained 3 x 108 non-infective particles. It appears from these findings that the single condition which will lead to the emergence of non-infective particles during the logarithmic period is a high initial particle-cell ratio. Because non-infective particles are equally as effective as infective particles in producing this result, it seems probable that the appearance of non-infective but hemagglutinating particles is not a necessary accompaniment of the reproductive process.

The relationships among nuptial coloration, aggression, and courtship of male three-spined sticklebacks, Gasterosteus aculeatus

1984 ◽  
Vol 62 (6) ◽  
pp. 999-1004 ◽  
Author(s):  
William J. Rowland
Keyword(s):  
Gasterosteus Aculeatus ◽  
Close Association ◽  
Positive Association ◽  
Hormonal Control ◽  
Stimulus Fish ◽  
Nuptial Coloration ◽  
Signal Value

A method was devised, using several independent judges, to estimate the degree of nuptial coloration of male three-spined sticklebacks, Gasterosteus aculeatus. Using the color-state scores that resulted from this technique, territorial males were compared with respect to their coloration level and with respect to their responsiveness to live and dummy stimulus fish. These comparisons reveal a positive association between color state and responsiveness: brightly colored males tend to court (zigzag) and attack (bite) stimulus fish more vigorously than duller colored males do. Therefore, the degree to which a male three-spined stickleback's nuptial coloration is developed can be used to some extent to predict its responsiveness, with the particular category of response (courtship or aggression) dependent on the stimulus presented. A close association between zigzag and bite frequencies was also found, responsive males showing higher levels of both courtship and aggression than less responsive ones. These results are consistent with evidence pertaining to the hormonal control of nuptial coloration, courtship, and aggression and to the signal value of nuptial coloration in G. aculeatus.

Effect of prolactin on the density of mucous cells on the gill filaments of the marine form (trachurus) of the threespine stickleback, Gasterosteus aculeatus L.

1969 ◽  
Vol 47 (5) ◽  
pp. 787-792 ◽  
Author(s):  
J. F. Leatherland ◽  
T. J. Lam
Keyword(s):  
Fresh Water ◽  
Intraperitoneal Injection ◽  
Gasterosteus Aculeatus ◽  
Mucous Cell ◽  
Threespine Stickleback ◽  
Mucous Cells ◽  
Treated Fish ◽  
Gill Filaments ◽  
Ovine Prolactin ◽  
Ambient Salinity

The density of the mucous cells on the gill filaments of the marine form (trachurus) of the threespine stickleback (Gasterosteus aculeatus L.) was investigated after changes of ambient salinity and intraperitoneal injection of ovine prolactin. Prolactin treatment appears to have no effect on the mucous cells of the seawater-adapted fish. Prolactin-treated fish showed a significantly higher density of gill mucous cells after 5 hours in fresh water when compared with solvent-injected controls. The differences among the prolactin-injected, solvent-injected, and uninfected groups were less marked after 1 and 4 days in fresh water. After 8 days in fresh water, however, the solvent-treated controls again had a significantly lower gill mucous cell density than their prolactin-treated contemporaries. The significance of these findings is discussed in relation to the osmotic and (or) ionic regulating properties of prolactin.

Stereo Electron Microscopy Applied to High Resolution Freeze-Etch Replicas

1970 ◽  
Vol 28 ◽  
pp. 306-307
Author(s):  
L. Andrew Staehelin
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
High Resolution ◽  
Smooth Surfaces ◽  
Small Particles ◽  
Membrane Surfaces ◽  
Wide Acceptance ◽  
New Information ◽  
Number Of Particles ◽  
Small Holes

Freeze-etched membranes usually appear as relatively smooth surfaces covered with numerous small particles and a few small holes (Fig. 1). In 1966 Branton (1“) suggested that these surfaces represent split inner mem¬brane faces and not true external membrane surfaces. His theory has now gained wide acceptance partly due to new information obtained from double replicas of freeze-cleaved specimens (2,3) and from freeze-etch experi¬ments with surface labeled membranes (4). While theses studies have fur¬ther substantiated the basic idea of membrane splitting and have shown clearly which membrane faces are complementary to each other, they have left the question open, why the replicated membrane faces usually exhibit con¬siderably fewer holes than particles. According to Branton's theory the number of holes should on the average equal the number of particles. The absence of these holes can be explained in either of two ways: a) it is possible that no holes are formed during the cleaving process e.g. due to plastic deformation (5); b) holes may arise during the cleaving process but remain undetected because of inadequate replication and microscope techniques.

Ruthenium red and alcian blue effects on outer structures of methanotrophic bacteria

1988 ◽  
Vol 46 ◽  
pp. 72-73
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
C.C. Remsen
Keyword(s):  
Research Effort ◽  
Ruthenium Red ◽  
Outer Cell ◽  
Methanotrophic Bacteria ◽  
En Bloc ◽  
Methylosinus Trichosporium ◽  
Wall Structures ◽  
Methylomonas Albus ◽  
Type Strains ◽  
Outer Cell Wall

Methane, a contributor to the “greenhouse effect”, is oxidized in the natural environment by methanotrophic bacteria. As part of a comprehensive research effort, we have been examining the ultrastructure of methanotrophs. These microorganisms have complex outer cell wall structures similar to those frequently found in other chemol itho- trophic bacteria. (1,2)In our work, we have focused on the “type” strains of Methylomonas albus BG8 and Methylosinus trichosporium OB3b. Between Spurr and LR White embedding resins, we found a difference 1n the preservation of an outer cup layer of BG8 external to the peripheral membranes. Cells from the same sample embedded in Spurr consistently lacked this feature (FIG. 1). This effect was overcome by an en bloc ruthenium red (RR) protocol that resulted in successful retention of the cup layer in Spurr resin (FIG. 2). For OB3b cells, the en bloc RR protocol resulted in an exterior bead feature distinguishable in thin section (FIG. 4) that previously was seen only by SEM.

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