scholarly journals THE CHANGE IN OSMOTICALLY INACTIVE FRACTION PRODUCED BY CELL ACTIVATION

1948 ◽  
Vol 32 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Herbert Shapiro
Keyword(s):  
Cell Volume ◽  
Sea Urchin ◽  
Cell Activation ◽  
Sea Water ◽  
Total Cell ◽  
Respiratory Metabolism ◽  
Arbacia Punctulata ◽  
Mechanical Analogue ◽  
Total Cell Volume ◽  
Cell Volumes

1. Resting and activated eggs of the sea urchin Arbacia punctulata were swollen in hypotonic sea water (60, 70, 80, and 90 per cent), and allowed to attain equilibrium volumes (Figs. 1 and 2). 2. Both fertilized and unfertilized eggs obey the Boyle-van't-Hoff law, but the value for b, the "osmotically inactive fraction" or non-swellable volume, was different for the two, averaging in the cases studied 7.3 per cent for unfertilized and 27.4 per cent for fertilized. 3. On activation, the eggs of the sea urchin undergo a definite increase in total cell volume, of approximately 2.7 per cent. 4. Some evidence is adduced for the possibility that the alteration in cell volume and in o.i.f. may depend upon the species in question. 5. A parallelism between change in b and alteration of respiratory metabolism in Arbacia, Chaetopterus, and Arbacia fragments is pointed out. This requires further investigation in other species to establish generality. 6. Equations for the calculation of the point at which osmotic pressures and cell volumes are identical for unfertilized and fertilized eggs are included. 7. A mechanical analogue of the phenomena is introduced (Fig. 3).

Needle microepiphytes in a Douglas fir canopy: biomass and distribution patterns

1979 ◽  
Vol 57 (9) ◽  
pp. 1000-1007 ◽  
Author(s):  
George C. Carroll
Keyword(s):  
Cell Volume ◽  
Distribution Patterns ◽  
Douglas Fir ◽  
Total Cell ◽  
Microbial Cell ◽  
Microbial Cells ◽  
Cutting Out ◽  
Total Cell Volume ◽  
Volume Estimates ◽  
Cell Volumes

Distribution patterns and total cell-volume estimates for needle microepiphytes are presented for three strata in the canopy of a single old-growth Douglas fir tree. Microbial cell volume was estimated by photographing transverse sections of needles, tracing microbial profiles on Mylar film, cutting out the tracings, and determining the pooled trace weights from various zones of each needle section. Microbial cells are concentrated in the midrib groove and over the stomatal zones of individual needles. Microbial cell volume on the upper needle surfaces increases during the 1st year and declines in subsequent years. Cell volumes on the lower needle surfaces increase from the 1st to the 3rd year and decrease from the 3rd to the 4th year. An increase in microbial cell volume occurs on both upper and lower surfaces from year 7 to year 8. Total microbial cell volume in relation to available needle surface area is greatest in the lower canopy and decreases with increasing height in the canopy. The total volume of microbial cells on needles was estimated to be 1093 cm3 for the entire tree.

scholarly journals THE EXTRACELLULAR RELEASE OF ECHINOCHROME

1946 ◽  
Vol 29 (5) ◽  
pp. 267-275 ◽  
Author(s):  
Herbert Shapiro
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Potassium Content ◽  
Red Pigment ◽  
Anaerobic Conditions ◽  
Outward Diffusion ◽  
Arbacia Punctulata ◽  
Extracellular Release

A study was made of the diffusion of the red pigment echinochrome from the eggs of the sea urchin, Arbacia punctulata, into sea water. Unfertilized eggs retained their pigment, over periods of hours. Outward diffusion of pigment from unfertilized eggs normally is entirely negligible, or does not occur at all. Enchancing the calcium or potassium content of the artificial sea water (while retaining isosmotic conditions) did not induce pigment release. Under anaerobic conditions, unfertilized eggs release pigment in small quantities. Fertilization alone brings about echinochrome release. Fertilized eggs invariably released pigment, whether in normal sea water, or sea water with increased calcium or potassium. This diffusion of the pigment began during the first cleavage, possibly soon after fertilization. The pigment release is not a consequence solely of the cell's permeability to echinochrome (or chromoprotein, or other pigment combination) but is preceded by events leading to a release of echinochrome from the granules in which it is concentrated within the cell. These events may be initiated by activation or by anaerobiosis. The phenomenon was not due to cytolysis.

scholarly journals V. Skeletal development in Arbacia , Echinarachnius and Leptasterias

1929 ◽  
Vol 217 (440-449) ◽  
pp. 289-334 ◽  
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Skeletal Development ◽  
Mediterranean Species ◽  
Marine Biological Laboratory ◽  
Glass Vessel ◽  
Arbacia Punctulata ◽  
Marine Biological ◽  
Points Of Interest ◽  
Arbacia Lixula

The echinopluteus of the genus Arbacia has been known since 1853. Echinoplutei of the species at present under investigation were first reared in 1880 by Fewkes, and two years later Garman and Colton (1882) succeeded in rearing them through the metamorphosis. The Mediterranean species Arbacia lixula , L. (syn. A . pustulosa , Gray) has also been reared through metamorphosis, and Übisch (1913) was the first to attempt an analysis of the test of the imago. The composition of the corona in the imago of A . pustulosa , as described in the paper just referred to (Übisch, 1913), is very different from that in the imago of e. g . Echinus or Strongylocentrotus . The opportunity of working at the Marine Biological Laboratory, Woods Hole, presenting itself, it was thought that a study of the development of the test in Arbacia punctulata , Gray, might reveal some points of interest. Accordingly, cultures of this common sea-urchin were started on July 28, 1926, and the echinoplutei were fed on the diatom Nitzschia closterium W. Sm. forma minutissima . Forty days later (September 6th) the first imago was obtained and the echinoplutei continued to metamorphose throughout the rest of September. Early in August a shallow glass vessel containing filtered sea-water was infected with plankton obtained by towing, and, by the first week of September, the bottom and sides of the vessel were well coated with diatoms. Many of the imagines, which measure 0·5 mm. in diameter including the spines, were transferred to this vessel and a number increased considerably in size. The largest specimen obtained in this way was 1·63 mm. in diameter inclusive of the spines; the diameter of the test alone was 0·9 mm.

scholarly journals Cellular dimensions affecting the nucleocytoplasmic volume ratio.

1991 ◽  
Vol 115 (4) ◽  
pp. 941-948 ◽  
Author(s):  
J A Swanson ◽  
M Lee ◽  
P E Knapp
Keyword(s):  
Endothelial Cells ◽  
Cell Volume ◽  
Volume Ratio ◽  
Fluorescein Isothiocyanate ◽  
Total Cell ◽  
Nuclear Volume ◽  
Size Exclusion ◽  
Nuclear Surface ◽  
Murine Bone Marrow ◽  
Total Cell Volume

Although it has long been appreciated that larger eukaryotic cells have larger nuclei, little is known about how this size relationship is maintained. Here we describe a method for measuring the aqueous volume ratio of nucleus to cytoplasm, two compartments which are interconnected via the pores in the nuclear envelope. We then use that method to identify proportional cellular dimensions in variously treated cells and in different cell types. Cells were scrape loaded with a mixture of fluorescent dextrans: Texas red dextran, average mol wt = 10,000 (TRDx10), and fluorescein isothiocyanate dextran, average mol wt = 70,000 (FDx70). After introduction into the cytoplasmic space, the TRDx10 distributed into both the nucleus and cytoplasm, whereas the FDx70 was restricted to cytoplasm, due to size exclusion by the nuclear pores. The aqueous nucleocytoplasmic volume ratio (RN/C) was determined by measuring, from fluorescence images of spread cells, total cellular fluorescence of each of the two probes and the fluorescence ratio of those probes in the cytoplasm. RN/C was unaffected by the measurement procedure or by varying temperatures between 23 degrees and 37 degrees C. Loading excess unlabeled dextrans had little effect on RN/C, with the single exception that high concentrations of large dextrans could lower RN/C in endothelial cells. Expanding intracellular membranous compartments of macrophages by phagocytosis of latex beads decreased RN/C. Expanding the same compartment by pinocytosis of sucrose, which nearly doubled total cell volume, had little effect on RN/C, indicating that nuclear volume was more closely linked to the cytoplasmic volume, exclusive of vesicular organelles, than to total cell volume. RN/C was the same in mononucleate and binucleate endothelial cells. Finally, measurements of RN/C in murine bone marrow-derived macrophages, bovine aortic endothelial cells, Swiss 3T3 fibroblasts, PtK2 cells, and CV-1 cells revealed that nuclear volume scaled allometrically with cell volume. The allometric relationship indicated that cell volume was proportional to nuclear surface area.

scholarly journals BLOOD DESTRUCTION DURING EXERCISE

1922 ◽  
Vol 36 (5) ◽  
pp. 481-500 ◽  
Author(s):  
G. O. Broun
Keyword(s):  
Cell Volume ◽  
Plasma Volume ◽  
Peripheral Blood ◽  
Prolonged Exercise ◽  
Jugular Vein ◽  
Total Cell ◽  
Total Cell Volume

The following changes have been demonstrated to take place in the blood of dogs during exercise. 1. An increase in the per cent of cells and hemoglobin in the blood of the jugular vein occurs early in the course of exercise. It probably results from a redistribution of red corpuscles, with an increase in their proportion in the peripheral blood. 2. As exercise is continued, there is a definite increase in plasma volume. 3. A coincident decrease both in the total cell volume and the pigment volume during prolonged exercise suggests that blood destruction then occurs.

Studies on dwarf larvae developed from isolated blastomeres of the starfish, Asterina pectinifera

Development ◽  
1978 ◽  
Vol 46 (1) ◽  
pp. 171-185
Author(s):  
Marina Dan-Sohkawa ◽  
Noriyuki Satoh
Keyword(s):  
Cell Volume ◽  
Larval Stage ◽  
Short Range ◽  
Total Cell ◽  
Cell Stage ◽  
Developmental System ◽  
Invertebrate Species ◽  
Total Cell Volume ◽  
Asterina Pectinifera

Not only a whole denuded egg, but also blastomeres isolated from 2-, 4- and 8-cell starfish embryos developed into morphologically normal, but dwarf bipinnariae, the sizes of which were roughly proportionate to that of the respective original blastomeres. Some of the blastomeres isolated from the 16-cell stage were also capable of developing into the larval stage. All isolated blastomeres divided in good synchrony with the control embryos. Blastulae of all groups gastrulated within quite a short range of time, around 14·5 h after insemination at 20±1 °C, although one-third of the 1/8-blastuIa missed this chance but gastrulated by 19·5 h. The number of constituent cells of the 1/8-gastrula was counted to be about 560, which corresponds roughly to one-half that of the 1/4-, one-fourth of the 1/2- and one-eighth of the 1/1-gastrula. This ratio also fitted roughly for the total cell volume. The results are compared with those of other invertebrate species, as well as of some vertebrates, and are discussed in connexion not only with the concepts of ‘regulative’ and ‘mosaic’ eggs, but also with a criterion that does not fit into either of these; the developmental system of the mammals.

scholarly journals THE EFFECT OF CERTAIN ELECTROLYTES AND NON-ELECTROLYTES ON PERMEABILITY OF LIVING CELLS TO WATER

1928 ◽  
Vol 12 (1) ◽  
pp. 129-138 ◽  
Author(s):  
Morton McCutcheon ◽  
Balduin Lucke
Keyword(s):  
Osmotic Pressure ◽  
Sea Urchin ◽  
Quantitative Study ◽  
Sea Water ◽  
Living Cells ◽  
Arbacia Punctulata ◽  
Dextrose Solution

1. Permeability to water in unfertilized eggs of the sea urchin, Arbacia punctulata, is found to be greater in hypotonic solutions of dextrose, saccharose and glycocoll than in sea water of the same osmotic pressure. 2. The addition to dextrose solution of small amounts of CaCl2 or MgCl2 restores the permeability approximately to the value obtained in sea water. 3. This effect of CaCl2 and MgCl2 is antagonized by the further addition of NaCl or KCl. 4. It is concluded that the NaCl and KCl tend to increase the permeability of the cell to water, CaCl2 and MgCl2 to decrease it. 5. The method here employed can be used for quantitative study of salt antagonism.

Three-dimensional reconstruction of organelles in Euglena gracilis Z. I. Qualitative and quantitative changes of chloroplasts and mitochondrial reticulum in synchronous photoautotrophic culture

1980 ◽  
Vol 43 (1) ◽  
pp. 137-166
Author(s):  
M. Pellegrini
Keyword(s):  
Cell Cycle ◽  
Cell Volume ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Light And Electron Microscopy ◽  
Total Cell ◽  
Ultrastructural Changes ◽  
Total Cell Volume ◽  
Euglena Gracilis Z ◽  
Mitochondrial Reticulum

Ultrastructural changes of chloroplasts and mitochondria have been observed in synchronously growing cells of Euglena gracilis Z, under photoautotrophic conditions. Application of the serial section technique allows estimation of the number and volume of these organelles. Several 3-dimensional reconstructions reveal their shape and distribution throughout the cell cycle. In young cells 10 separate diskoid or branched chloroplasts are found. They show the typical lamellar structure of euglenoid chloroplasts. During the growth phase (light period), they enlarge and their volume doubles. Some of them branch out, so that 20 lobes are formed. Thylakoids grow longer without change in number. The pyrenoid persists only during the first half of this period. During the cell division phase (dark period), branched chloroplasts divide along 2 planes which are perpendicular to each other and perpendicular to the thylakoid plane. All thylakoids are cut and their number does not change in the daughter chloroplasts. The plastidome volume constitutes 15–18% of the total cell volume over the entire life cycle. One of the most significant observations in this report is the presence of a single permanent mitochondrial reticulum during the whole cell cycle. This giant mitochondrion consists of an extremely branched network with delicate threads (0.4-0.6 micrometer thick) surrounding the chloroplasts, nucleus and reservoir. It extends throughout the cell. During the growth phase, it becomes gradually longer and doubles in volume. The degree of branching increases but the thickness of the threads remains constant. During the division phase, the mitochondrial elements appear more restricted (0.4 micrometer thick) and the reticulum becomes progressively partitioned into 2 daughter networks. At any time of the cell cycle, the chondriome volume is about 6% of the total cell volume. These results are discussed in comparison with numerous relevant papers on light and electron microscopy of animal and plant cells. They suggest that the descriptions of several authors on the plastidial cycle and the mitochondrial cycle in Euglena, both said to be characterized by alternate reticulate and fragmentary states, arise in part from questionable interpretation of random sections. It is evident that the form and distribution of organelles can be determined more precisely by serial sectioning.

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