Nuclear proteins of quiescent and mitotically active cells in shoot meristems of Tradescantia paludosa

1974 ◽  
Vol 52 (9) ◽  
pp. 2049-2053 ◽  
Author(s):  
R. S. Tobin ◽  
Kyu-Byung Yun ◽  
J. M. Naylor
Keyword(s):  
Nuclear Proteins ◽  
Zone Of Inhibition ◽  
Interphase Nuclei ◽  
Lateral Buds ◽  
Dye Binding ◽  
Tradescantia Paludosa ◽  
Shoot Meristems

In inhibited lateral buds of Tradescantia paludosa, interphase nuclei in the apical zone of inhibition contain higher levels of arginine per unit DNA than those of mitotically active cells in interphase or prophase. Supplementary dye-binding experiments suggest that this reflects a corresponding difference between the composition of the histone complement of chromatin in the two cells populations. The possible implications of this phenomenon are discussed.

The Synthesis and Migration of Nuclear Proteins during Mitosis and differentiation of Cells in Rats

1965 ◽  
Vol s3-106 (75) ◽  
pp. 229-240
Author(s):  
R. T. SIMS
Keyword(s):  
Granular Cell ◽  
Nuclear Proteins ◽  
Photographic Emulsion ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Cell Layers ◽  
The Difference ◽  
Mitotic Figures ◽  
And Migration ◽  
Silver Grains

Hooded rats were given an intraperitoneal injection of 3H-tyrosine, and killed in pairs 10 min, 30 min, 12 h, 36 h, 7 days, and 30 days later. A piece of skin with white growing hair, and the tongue, were taken from each animal and radioautographs were prepared. Silver grains were counted over whole nuclei and whole mitotic figures of the germinal cells and whole nuclei of differentiating cells of both tissues. It was found that the interphase nuclei have significantly more silver grains over them than the chromosomes at all stages of mitosis and there are virtually no grains over metaphase, anaphase, and early telophase chromosomes in both tissues of all the animals killed up to 36 h after the injection. The difference between the grain counts over the interphase nuclei and the chromosomes of dividing cells is at least 20-fold at 30 min in the hair matrix, at least 5-fold at 30 min in the tongue and at 36 h in both tissues. It was established that the differences observed between the radioactivities of the nuclei and chromosomes of mitotic figures are real from estimates of: the radioactivity of the cell cytoplasm, volumes of the metaphase chromosomes and interphase nuclei within 1µ of the photographic emulsion, and the volumes of cytoplasm separating the photographic emulsion and these structures. No protein synthesis was demonstrable in the chromosomes during metaphase, anaphase, and early telophase. Nuclear proteins leave the chromosomes during prophase and prometaphase and return to the nucleus during late telophase. The cells in the matrix and upper bulb of the growing hair follicle and those in the germinal, prickle, and granular cell layers of the tongue are in different functional states; 30 min after injection of 3H-tyrosine they have different amounts of it in their nuclear proteins. It is suggested that the amount incorporated into each nucleus is related to the rate at which proteins are being synthesized by the cell.

Influence of apical dominance on the nuclear proteins in cells of the lateral bud meristem in Tradescantia paludosa

1968 ◽  
Vol 46 (3) ◽  
pp. 289-298 ◽  
Author(s):  
R. S. Dwivedi ◽  
J. M. Naylor
Keyword(s):  
Deoxyribonucleic Acid ◽  
Physiological State ◽  
Total Protein Content ◽  
Zone Of Inhibition ◽  
Terminal Bud ◽  
Interphase Cells ◽  
Standard Level ◽  
Lateral Bud ◽  
Standard Value ◽  
Tradescantia Paludosa

In inhibited axillary buds of Tradescantia paludosa deoxyribonucleic acid, (DNA) synthesis is blocked at the 2C (GI) level in a group of cells which constitute a "zone of inhibition" in the bud apex. The apparent DNA/histone ratio of chromatin in these interphase cells is substantially higher than the "standard" value found in nuclei of the active terminal bud. The DNA/histone ratio of chromatin in the apex of the axillary bud declines to the standard level when the cells undergo changes leading to mitosis, after the release of inhibition. In contrast to the histone level, the total protein content of chromatin in the zone of inhibition is not influenced by the change in physiological state of the bud. The significance of this shift in the histone content of chromatin is discussed.

Timing of insecticidal sprays to control the wheat-bulb fly, Leptohylemyia coarctata (Fall.)

1969 ◽  
Vol 58 (4) ◽  
pp. 793-801 ◽  
Author(s):  
D. C. Griffiths ◽  
G. C. Scott
Keyword(s):  
Field Trial ◽  
Large Field ◽  
Leaf Stage ◽  
Stage Of Development ◽  
Lateral Buds ◽  
Sowing Dates ◽  
Lateral Shoots ◽  
Fly Larvae ◽  
Main Growth ◽  
Shoot Meristems

The timing of sprays in relation to the stage of development of wheat plants and larvae of the wheat-bulb fly, Leptohylemyia coarctata (Pall.), was studied in the laboratory and field. The main growth of young wheat plants was of the centre shoot and such plants died when the centre shoot meristems were destroyed. Older plants survived by growth of lateral shoots. Sprays of dimethoate, trichloronate and thionazin applied before the larvae had emerged did not kill many larvae in the soil, and only insecticide that entered the plants was effective. Severely attacked two-leaf plants yielded little, whether sprayed or not, whereas three-leaf plants sprayed in early March gave a worth-while increase in yield: older plants had enough shoots to give moderate yields even when not sprayed.In a large field trial, plants from two sowing dates, 22nd October and 1st November, were both at the late two-leaf stage of growth in late February. Wheat-bulb fly larvae had entered nearly all the shoots but plants from both sowings had buds or small lateral growths hidden beneath the outer leaves. The yields of October-sown plots sprayed on 22nd February, 2nd March, 9th March or 16th March were 28·2, 28·8, 25·5 and 23·2 cwt. grain per acre, respectively, (yield of unsprayed plots = 18.9 cwt./acre) and of November-sown plots were 31·0, 27·5, 17·9 and 14·9 cwt. per acre, respectively, (yield of unsprayed plots = 116 cwt. per acre). Sprays had most effect when applied soon after larvae had entered the plants. Spraying severely-attacked late two-leaf to three-leaf plants gave the greatest benefits because these plants recovered by growth of lateral buds or small lateral shoots.

EFFETS DES MICROIRRADIATIONS SUR LES MICROSPOROCYTES ET MICROSPORES DE TRADESCANTIA PALUDOSA. III. NOTE PRÉLIMINAIRE SUR LES EFFETS DES MICROIRRADIATIONS ULTRAVIOLETTES

1973 ◽  
Vol 15 (1) ◽  
pp. 39-44
Author(s):  
G. Garot ◽  
M. Dujardin ◽  
A. Gilles
Keyword(s):  
Chromosome Structure ◽  
Interphase Nuclei ◽  
Remarkable Effect ◽  
Anaphase Bridges ◽  
Selective Destruction ◽  
Tradescantia Paludosa

Microsporocytes of Tradescantia paludosa have been irradiated with ultraviolet microbeams of 2 to 10 microns. At a wavelength of 2570 A, we observe a selective destruction, total or partial, of the spindle in the first division, anaphase bridges and interruption in the second division.At a wavelength of 2750 A, the most remarkable effect is the "paling" of some parts of the chromosome structure as well as of interphase nuclei, and also stickiness bridges in the bivalents of the first division.

GROWTH OF POLLEN GRAIN NUCLEI OF TRADESCANTIA PALUDOSA

1976 ◽  
Vol 18 (2) ◽  
pp. 385-393 ◽  
Author(s):  
R. L. White ◽  
D. Davidson
Keyword(s):  
Normal Distribution ◽  
Root Meristem ◽  
Pollen Grain ◽  
Nuclear Volume ◽  
Interphase Nuclei ◽  
Rate Of Increase ◽  
Log Normal ◽  
Straight Lines ◽  
Log Normal Distribution ◽  
Tradescantia Paludosa

Pollen grain nuclei of Tradescantia paludosa Anderson and Woodson had a mean volume of 122 μm3 in early G1 and 1,415 μm3 in late G2. The distribution of nuclear volumes was not linear normal; however, it closely approximated a log normal distribution and probit plots yielded straight lines for the central 85-90% of the values. Most nuclei were spherical or nearly-spherical in early G1 but their increase in volume was accompanied by a change to an ovaloid or elongate shape. Interphase in the pollen grain lasted about five days at 25 °C. In the first 3.5 days the rate of increase in mean nuclear volume was about 87 μm3 per day. In the last 1.5 days of pollen grain interphase, nuclei increased at a mean rate of 658 μm3 per day; nuclear growth was relatively slow in G1 and rapid in G2. The largest nuclei tended to divide first; the result was that as the proportion of nuclei that have divided increased, mean nuclear volume decreased from 1415 μm3 to 680 μm3. Nuclear volumes were also determined for diploid nuclei of root meristem and sporogenous cells; their mean volumes were smaller, 1,355 μm3 and 1,018 μm3, than that of the G2 haploid nuclei, 1,415 μm3.

scholarly journals THE CYTONUCLEOPROTEINS OF AMEBAE

1963 ◽  
Vol 19 (3) ◽  
pp. 467-475 ◽  
Author(s):  
Thomas J. Byers ◽  
Dorothy B. Platt ◽  
Lester Goldstein
Keyword(s):  
Amino Acid ◽  
Migration Rate ◽  
Nuclear Proteins ◽  
Interphase Nuclei ◽  
Donor Nucleus ◽  
Equilibrium Ratio ◽  
Protein Label ◽  
Host Nucleus ◽  
In Cells

Radioactivity, apparently in cytonucleoproteins, from an amino acid-labeled nucleus implanted into a non-radioactive cell appeared in the host nucleus within 10 minutes, and the typical equilibrium ratio 70:30 donor nucleus radioactivity:host nucleus radioactivity was reached in 4 to 5 hours at 25°C. If such binucleates grew and divided, no localization of radioactivity was observable in cells fixed during mitosis, but the protein label remained concentrated in the daughter interphase nuclei for at least 4 generations. Continued migration of cytonucleoproteins was observed if these daughter nuclei were transplanted to other unlabeled cells. The Q10 (19° to 29°C) of the migration rate of radioactive cytonucleoproteins was ca. 1.3, suggesting that passage through the cytoplasm occurred by diffusion. Both non-migratory nuclear proteins and cytonucleoproteins appear to be synthesized in the cytoplasm.

Protamine-DNA interaction

1978 ◽  
Vol 36 (2) ◽  
pp. 200-201
Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer
Keyword(s):  
Small Volume ◽  
Double Helix ◽  
Dna Interaction ◽  
Dark Field ◽  
Sperm Head ◽  
Nuclear Proteins ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Dna Double Helix ◽  
Positively Charged

Dark field electron microscopy has been used for the study of the structure of individual macromolecules with a resolution to at least the 5Å level. The use of this technique has been extended to the investigation of structure of interacting molecules, particularly the interaction between DNA and fish protamine, a class of basic nuclear proteins of molecular weight 4,000 daltons.Protamine, which is synthesized during spermatogenesis, binds to chromatin, displaces the somatic histones and wraps up the DNA to fit into the small volume of the sperm head. It has been proposed that protamine, existing as an extended polypeptide, winds around the minor groove of the DNA double helix, with protamine's positively-charged arginines lining up with the negatively-charged phosphates of DNA. However, viewing protamine as an extended protein is inconsistent with the results obtained in our laboratory.

Nuclear proteins in primary biliary cirrhosis as guardians against HCC development

2013 ◽  
Vol 51 (01) ◽  
Author(s):  
C Hintemann ◽  
K Straub ◽  
S Biesterfeld ◽  
PR Galle ◽  
J Erthle ◽  
...  
Keyword(s):  
Primary Biliary Cirrhosis ◽  
Nuclear Proteins ◽  
Biliary Cirrhosis

GENE ACTIVATION IN MAMMARY CELLS

1972 ◽  
Vol 71 (2_Suppla) ◽  
pp. S346-S368 ◽  
Author(s):  
Roger W. Turkington ◽  
Nobuyuki Kadohama
Keyword(s):  
Cell Differentiation ◽  
Gene Transcription ◽  
Hormonal Regulation ◽  
Gene Activation ◽  
Milk Proteins ◽  
Mouse Mammary Gland ◽  
Nuclear Proteins ◽  
Mammary Cells ◽  
Alveolar Cells ◽  
Mammary Cell

ABSTRACT Hormonal activation of gene transcription has been studied in a model system, the mouse mammary gland in organ culture. Transcriptive activity is stimulated in mammary stem cells by insulin, and in mammary alveolar cells by prolactin and insulin. Studies on the template requirement for expression of the genes for milk proteins demonstrate that DNA methylation has an obligatory dependence upon DNA synthesis, but is otherwise independent from hormonal regulation of mammary cell differentiation. Incorporation of 5-bromo-2′deoxyuridine into DNA selectively inhibits expression of the genes for specific milk proteins. Undifferentiated mammary cells activate the synthesis of specific acidic nuclear proteins when stimulated by insulin. Several of these induced acidic nuclear proteins are undetectable in unstimulated undifferentiated cells, but appear to be characteristic components of the nuclei of differentiated cells. These results indicate that mammary cell differentiation is associated with a change in acidic nuclear proteins, and they provide evidence to support the concept that acidic nuclear proteins may be involved in the regulation of gene transcription and of mammary cell differentiation.

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