scholarly journals CHANGING NUCLEAR HISTONE PATTERNS DURING DEVELOPMENT III. THE DEOXYRIBONUCLEIC ACID CONTENT OF SPERMATOGENIC CELLS IN THE CRAB EMERITA ANALOGA

1969 ◽  
Vol 17 (9) ◽  
pp. 591-600 ◽  
Author(s):  
J. C. VAUGHN ◽  
R. D. LOCY
Keyword(s):  
Deoxyribonucleic Acid ◽  
Rat Tissues ◽  
Spermatogenic Cells ◽  
Spectral Absorption ◽  
Naturally Occurring ◽  
Emerita Analoga ◽  
Dna Contents ◽  
Nuclear Histone ◽  
Sperm Nuclei ◽  
Sperm Maturity

The deoxyribonucleic acid (DNA) content of spermatogenic cells of the decapod crab, Emerita analoga, has been cytophotometrically determined at various stages of development, using Feulgen-stained nuclei. The haploid DNA value is found to be 2.9 x 10–12 g, regardless of the nuclear histone content, which drops to cytochemically indetectable levels by sperm maturity. In determining this value, a precise extinction coefficient for Feulgen-stained nuclei was first determined using chicken, frog and toad erythrocyte nuclei and also nuclei from various rat tissues. The effect of naturally occurring nuclear histone depletion on the quantitative Feulgen reaction has also been examined. Identical hydrolysis curves and Feulgen spectral absorption curves are found for somatic nuclei, which contain a full histone complement, and for mature sperm nuclei, which do not contain histones. Loss of nuclear histone does not lead to a change in total Feulgen dye bound per nucleus, as early, middle and late spermatids have equal DNA contents as reflected by Feulgen binding, and primary spermatocytes contain 4 times this value, as expected from the DNA constancy law. The effect of histones (and other proteins) on quantitative Feulgen microspectrophotometry is discussed.

scholarly journals The presence of 5-hydroxymethylcytosine in animal deoxyribonucleic acid

1972 ◽  
Vol 126 (4) ◽  
pp. 781-790 ◽  
Author(s):  
N. W. Penn ◽  
R. Suwalski ◽  
C. O'Riley ◽  
K. Bojanowski ◽  
R. Yura
Keyword(s):  
Deoxyribonucleic Acid ◽  
Phosphorus Content ◽  
Alkaline Solutions ◽  
Small Scale ◽  
Rat Tissues ◽  
Adult Rat ◽  
Frog Brain ◽  
Rat Brain And Liver ◽  
Scale Preparation ◽  
Rat Tissue

A method is given for small-scale preparation of DNA from 1.0–1.5g of adult rat tissues. The product from brain or liver is characterized by base ratios and phosphorus content which accord with reported values for rat tissue. It is reasonably free of RNA, protein and glycogen. It contains 5-hydroxymethylcytosine at a content of about 15% of the total cytosine bases present. 5-Hydroxymethylcytosine is also demonstrable in mouse and frog brain DNA and in the crude cytidylic acid fractions obtained from RNA hydrolysates of rat brain and liver. 5-Hydroxymethylcytosine is identified by paper chromatography, u.v. spectra in acid and alkaline solutions and by its conversion into 5-hydroxymethyluracil.

scholarly journals MICROCHEMICAL DEOXYRIBONUCLEIC ACID DETERMINATION IN INDIVIDUAL CELLS

1961 ◽  
Vol 9 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Jan-Erik Edström ◽  
Jerzy Kawiak
Keyword(s):  
Dna Content ◽  
Mitotic Cycle ◽  
Deoxyribonucleic Acid ◽  
Test Material ◽  
Cell Nuclei ◽  
Fixed Tissue ◽  
Dna Contents ◽  
Two Factors ◽  
Good Agreement

A method for the quantitative determination of DNA in the 50 to 500 µµg. range is presented. Cells or cell nuclei are isolated individually from fixed tissue by means of micromanipulation. The tissue units in question are extracted in an oil chamber with deoxyribonuclease solution. The extracts are evaporated to dryness and redissolved to lens-shaped drops, the DNA contents of which are determined by a photographic-photometric procedure in ultraviolet light. Determinations on calf thymocytes and rat spermatids show a relatively good agreement with biochemical data. The present method tends, however, to give some. what higher values than those reported earlier. The coefficient of variation for analytical values from test material is about ± 10 per cent. The method has been applied to cells from the axolotl, adults as well as tadpoles. Germ cells (spermatids and spermatocytes) do not show any evidence of a biological variation in DNA content. Cells from proliferating tissues give an increased spread of the DNA values. It could be shown, for epithelial cells, that there are at least two factors determining the DNA content of these cells. One is the fact that the cells are investigated at different phases of the mitotic cycle; the other is the fact that the DNA synthesis cycle occupies different ranges for different cells.

The Synthesis of Deoxyribonucleic Acid and Nuclear Histone of the X Chromosome of the Rehnia Spinosus Spermatocyte

1969 ◽  
Vol 5 (2) ◽  
pp. 321-332 ◽  
Author(s):  
D. P. BLOCH ◽  
CHRISTINA TENG
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dna Replication ◽  
X Chromosome ◽  
Deoxyribonucleic Acid ◽  
Chromosome Replication ◽  
Amino Acid Incorporation ◽  
Acid Incorporation ◽  
Nuclear Histone

The X chromosome of the Rehnia spinosus (Orthoptera) spermatocyte exists in a vesicle separate from the rest of the nucleus during its replication. This chromosome is typically heterochromatic, and late replicating. After replication the chromosome vesicle fuses with the nucleus. Cytophotometric determination of DNA and histone during replication of the chromosome revealed two types of histone. One class increases in amount in proportion to the DNA. The second class remains constant as DNA doubles, and probably increases later. Autoradiographic studies of incorporation of amino acids indicates that histone labelling occurs during chromosome replication. However, a lag in amino acid incorporation suggests that DNA replication in the X chromosome, while accompanied, or closely followed, by complexing with histone, is not necessarily coupled with its synthesis.

scholarly journals Chemical carcinogenesis in the nervous system. Preferential accumulation of O6-methylguanine in rat brain deoxyribonucleic acid during repetitive administration of N-methyl-N-nitrosourea

1975 ◽  
Vol 148 (3) ◽  
pp. 521-525 ◽  
Author(s):  
G P Margison ◽  
P Kleihues
Keyword(s):  
Nervous System ◽  
Deoxyribonucleic Acid ◽  
Chemical Carcinogenesis ◽  
Dose Schedule ◽  
Rat Tissues ◽  
Final Injection ◽  
Repair Deficiency ◽  
Kinetics Of ◽  
The Brain ◽  
Determining Factor

The alkylation of purine bases in DNA of several rat tissues was determined during weekly injections (10 mg/kg) of N-[3H]methyl-N-nitrosourea, a dose schedule known to selectively induce tumours of the nervous system. Each group of animals was killed 1 week after the final injection, and the DNA hydrolysates were analysed by chromatography on Sephadex G-10. After five weekly applications, O6-methylguanine had accumulated in brain DNA to an extent which greatly exceeded that in kidney, spleen and intestine. In the liver, the final O6-methylguanine concentration was less than 1% of that in brain. Between the first and the fifth injection, the O6-methylguanine/7-methylguanine ratio in cerebral DNA increased from 0.28 to 0.68. In addition, 3-methylguanine was found to accumulate in brain DNA whereas in the other organs no significant quantities of this base were detectable. The results are compatible with the hypothesis that O6-alkylation of guanine in DNA plays a major role in the induction of tumours by N-methyl-N-nitrosourea and related carcinogens. The kinetics of the increase of O6-methylguanine in cerebral DNA suggest that there is no major cell fraction in the brain which is capable of excising chemically methylated bases from DNA. This repair deficiency could be a determining factor in the selective induction of nervous-system tumours by N-methyl-N-nitrosourea and other neuro-oncogenic compounds.

Effects of X-radiation on thymidine incorporation and deoxyribonucleoprotein integrity in rat tissues

1969 ◽  
Vol 47 (11) ◽  
pp. 1003-1006 ◽  
Author(s):  
D. K. Myers ◽  
S. Ram
Keyword(s):  
Dna Synthesis ◽  
Deoxyribonucleic Acid ◽  
Thymidine Incorporation ◽  
Rat Tissues ◽  
Lethal Effects ◽  
Early Effect ◽  
Inhibition Of Dna Synthesis ◽  
Postradiation Period ◽  
Observation Period

The early effect of X-radiation on thymidine incorporation into deoxyribonucleic acid (DNA) did not differ markedly in rat tissues which are resistant and those which are sensitive to the lethal effects of irradiation. Inhibition of DNA synthesis was accompanied by loss of integrity of deoxyribonucleoprotein (DNAP) in all tissues examined during the postradiation period. The cells of radioresistant tissues were able to repair the postradiation damage to DNAP, while the degradation of DNAP continued unchecked in radiosensitive tissues during a 24-h observation period.

scholarly journals Probability paper analysis of flow cytofluorometric measurements of cellular deoxyribonucleic acid content.

1981 ◽  
Vol 29 (7) ◽  
pp. 851-857 ◽  
Author(s):  
J E Neely ◽  
J W Combs
Keyword(s):  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Paper Analysis ◽  
S Phase ◽  
Flow Cytofluorometry ◽  
Normal Distributions ◽  
Probability Paper ◽  
Graphic Analysis ◽  
Dna Contents ◽  
Dna Histograms

A graphic analysis of cellular deoxyribonucleic acid (DNA) histograms obtained by flow cytofluorometry is described. This technique utilizes probability paper that graphs data in cumulative percentile form. From this graphic representation, individual normal distributions contributing to the histogram may be isolated and statistically describe. G0G1 and G2M distributions are independently described and S phase is fit to 1--5 overlapping normal distributions as dictated by the analysis results. This technique offers several advantages, including relatively simple mathematical calculations and few assumptions or restraints placed on the analysis. It has proved to be useful in analyzing proliferating and nonproliferating populations as well as distributions with unusual findings such as debris or aberrant DNA contents.

Sign in / Sign up

Export Citation Format

Share Document