Analysis of plant genomes. IV. Isolation and characterization of satellite DNA components from two dicotyledons cucumber (Cucumis sativus) and radish (Raphanus sativus)

1978 ◽  
Vol 56 (8) ◽  
pp. 808-815 ◽  
Author(s):  
P. K. Ranjekar ◽  
D. Pallotta ◽  
J. G. Lafontaine
Keyword(s):  
Satellite Dna ◽  
Raphanus Sativus ◽  
Nuclear Dna ◽  
Minor Component ◽  
Isolation And Characterization ◽  
Dna Contents ◽  
A Minor ◽  
Dna Components ◽  
Denaturation Profile

Satellite DNA fractions from cucumber and radish, two plants having low DNA contents and relatively small chromosomes, were isolated and characterized. Reassociation studies of satellite and total nuclear DNA showed that the satellite fractions in these two plants contain most of the rapidly reassociating DNA. Cucumber satellite I was found to contain one major component (70% of the total satellite) having a density of 1.706 g/cm3 and a Tm of 90.5 °C and a minor component with a density of 1.712 g/cm3 and a Tm of 93.5 °C. The complexity of the major component was estimated to be 3.8 × 105 daltons while that of the minor one was 12.9 × 107 daltons. Although cucumber satellite II banded as a single peak at adensity of 1.700 g/cm3 in neutral CsCl gradients, it was observed to have a rather broad denaturation profile with a Tm of 86.5 °C. Its Cot curve was also broader than that of satellite I and one of its components (40% of the total) had a complexity of 5.8 × 105 daltons. Two satellite fractions were also observed in the case of radish DNA but only satellite I was isolated in a pure form and characterized. This radish satellite formed a sharp, symmetrical peak at a density of 1.698 g/cm3 in neutral CsCl gradients and underwent denaturation in a narrow temperature range of 6 to 7 °C. An analysis of the optical reassociation kinetics showed that this satellite contained a major and a minor component. The major component, which comprised 80% of the satellite, had a complexity of 12.9 × 105 daltons. Hybridization experiments revealed that the ribosomal DNA was present in satellite II.

scholarly journals Biochemical studies on the isolation and characterization of human spleen haemosiderin

1984 ◽  
Vol 223 (1) ◽  
pp. 31-38 ◽  
Author(s):  
M P Weir ◽  
J F Gibson ◽  
T J Peters
Keyword(s):  
Minor Component ◽  
Iron Oxyhydroxide ◽  
Human Spleen ◽  
Major Band ◽  
Isolation And Characterization ◽  
Biochemical Studies ◽  
Characteristic Group ◽  
A Minor ◽  
Proteolytic Product

Haemosiderin was isolated from thalassaemic human spleens by centrifugation through concentrated KI solutions. A method for solubilizing haemosiderin was developed which leaves the iron oxyhydroxide cores and constituent polypeptides intact, facilitating further purification and analysis. Purified haemosiderin contained no detectable haem, trace amounts of carbohydrate, and iron and phosphorus in a molar ration of 6:1; much of the phosphate may be present as core-adsorbed. Several lipids were present, but it is not certain whether these are contaminants or components of the haemosiderin granules. In all preparations examined, a characteristic group of six to seven peptides of apparent Mr 12 900-17 800 were found, with a major band at Mr 14 500 and, in addition, a minor component of Mr 42 000; these peptides co-chromatographed with the cores. Negatively stained electron micrographs suggest that these peptides form an incomplete shell about the cores, consistent with the view that haemosiderin is a proteolytic product of ferritin.

Functional Characterization of GABAA Receptors in Neonatal Hypothalamic Brain Slice

2002 ◽  
Vol 88 (4) ◽  
pp. 1655-1663 ◽  
Author(s):  
Ren-Qi Huang ◽  
Glenn H. Dillon
Keyword(s):  
Functional Characterization ◽  
Minor Component ◽  
Dehydroepiandrosterone Sulfate ◽  
Receptor Subtypes ◽  
Hypothalamic Neurons ◽  
Inhibitory Neurotransmitter ◽  
Old Rats ◽  
A Minor ◽  
Whole Cell Recordings

The hypothalamus influences a number of autonomic functions. The activity of hypothalamic neurons is modulated in part by release of the inhibitory neurotransmitter GABA onto these neurons. GABAA receptors are formed from a number of distinct subunits, designated α, β, γ, δ, ε, and θ, many of which have multiple isoforms. Little data exist, however, on the functional characteristics of the GABAA receptors present on hypothalamic neurons. To gain insight into which GABAA receptor subunits are functionally expressed in the hypothalamus, we used an array of pharmacologic assessments. Whole cell recordings were made from thin hypothalamic slices obtained from 1- to 14-day-old rats. GABAA receptor-mediated currents were detected in all neurons tested and had an average EC50 of 20 ± 1.6 μM. Hypothalamic GABAA receptors were modulated by diazepam (EC50 = 0.060 μM), zolpidem (EC50 = 0.19 μM), loreclezole (EC50 = 4.4 μM), methyl-6,7-dimethoxy-4-ethyl-β-carboline (EC50= 7.7 μM), and 5α-pregnan-3α-hydroxy-20-one (3α-OH-DHP). Conversely, these receptors were inhibited by Zn2+ (IC50 = 70.5 μM), dehydroepiandrosterone sulfate (IC50 = 16.7 μM), and picrotoxin (IC50 = 2.6 μM). The α4/6-selective antagonist furosemide (10–1,000 μM) was ineffective in all hypothalamic neurons tested. The results of our pharmacological analysis suggest that hypothalamic neurons express functional GABAA receptor subtypes that incorporate α1 and/or α2 subunits, β2 and/or β3 subunits, and the γ2 subunit. Our results suggest receptors expressing α3–α6, β1, γ1, and δ, if present, represent a minor component of functional hypothalamic GABAA receptors.

Isolation and characterization of tandem repeats in nematode genomes.

2021 ◽  
pp. 240-249
Author(s):  
Philippe Castagnone-Sereno
Keyword(s):  
Case Studies ◽  
Genetic Markers ◽  
Satellite Dna ◽  
Entomopathogenic Nematodes ◽  
Tandem Repeats ◽  
Genomic Resources ◽  
Isolation And Characterization ◽  
Nematode Genomes ◽  
Plant Parasitic

Abstract This chapter provides an overview of the practical methodologies that can be used to identify and characterize the tandem repeats that are most frequently used as genetic markers in nematodes (including plant-parasitic and entomopathogenic nematodes), namely satellite DNA and microsatellites. The objective is not to provide turnkey protocols, but rather to return to the main principles that govern these protocols. Case studies on nematodes will serve to illustrate the point. In that respect, two well-defined situations are to be considered, depending on whether genomic resources for the species under investigation are available or not.

Isolation and characterization of a satellite DNA family in the Saccharum complex

Genome ◽  
1998 ◽  
Vol 41 (6) ◽  
pp. 854-864 ◽  
Author(s):  
Karine Alix ◽  
Franc-Christophe Baurens ◽  
Florence Paulet ◽  
Jean-Christophe Glaszmann ◽  
Angélique D'Hont
Keyword(s):  
Satellite Dna ◽  
Isolation And Characterization

Isolation and characterization of a mitochondrial RNA polymerase from Drosophila melanogaster

1987 ◽  
Vol 65 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Michael Goldenthal ◽  
James T. Nishiura
Keyword(s):  
Drosophila Melanogaster ◽  
Rna Polymerase ◽  
Nuclear Dna ◽  
Gradient Centrifugation ◽  
Mitochondrial Rna ◽  
Mitochondrial Rna Polymerase ◽  
Isolation And Characterization ◽  
Cscl Gradient ◽  
Nuclear Rna

A DNA-dependent RNA polymerase was solubilized from sucrose gradient isolated, DNase-treated mitochrondria of Drosophila melanogaster. The isolated mitochondria were not detectably contaminated with nuclear DNA as shown by CsCl gradient centrifugation and polylysine Kieselguhr chromatography. The detergent-solubilized RNA polymerase was sensitive to rifampicin, resistant to α-amanitin, had an apparent molecular mass of about 60 kilodaltons, and displayed a tendency to aggregate, both in crude extracts or when purified. The mitochondrial RNA polymerase could be distinguished from nuclear RNA polymerases on the basis of size, salt optima, rifampicin sensitivity, and α-amanitin resistance.

scholarly journals Isolation and characterization of a minor fimbria from Porphyromonas gingivalis.

1996 ◽  
Vol 64 (11) ◽  
pp. 4788-4794 ◽  
Author(s):  
N Hamada ◽  
H T Sojar ◽  
M I Cho ◽  
R J Genco
Keyword(s):  
Porphyromonas Gingivalis ◽  
Isolation And Characterization ◽  
A Minor

scholarly journals Purification and Characterization of Thin Pili of IncI1 Plasmids ColIb-P9 and R64: Formation of PilV-Specific Cell Aggregates by Type IV Pili

1998 ◽  
Vol 180 (11) ◽  
pp. 2842-2848 ◽  
Author(s):  
Tetsu Yoshida ◽  
Nobuhisa Furuya ◽  
Masayuki Ishikura ◽  
Toshiaki Isobe ◽  
Kazu Haino-Fukushima ◽  
...  
Keyword(s):  
Gradient Centrifugation ◽  
Minor Component ◽  
Electrophoretic Analysis ◽  
Type Iv Pili ◽  
Specific Cell ◽  
Cell Aggregates ◽  
Type Iv ◽  
Cscl Density Gradient ◽  
A Minor

ABSTRACT Thin pili of the closely related IncI1 plasmids ColIb-P9 and R64 are required only for liquid mating and belong to the type IV family of pili. They were sedimented by ultracentrifugation from culture medium in which Escherichia coli cells harboring ColIb-P9- or R64-derived plasmids had been grown, and then the pili were purified by CsCl density gradient centrifugation. In negatively stained thin pilus samples, long rods with a diameter of 6 nm, characteristic of type IV pili, were observed under an electron microscope. Gel electrophoretic analysis of purified ColIb-P9 thin pili indicated that thin pili consist of two kinds of proteins, pilin and the PilV protein. Pilin was demonstrated to be the product of the pilS gene. Pilin was first synthesized as a 22-kDa prepilin from the pilS gene and subsequently processed to a 19-kDa protein by the function of thepilU product. The N-terminal amino group of the processed protein was shown to be modified. The C-terminal segments of thepilV products vary among six or seven different types, as a result of shufflon DNA rearrangements of the pilV gene. These PilV proteins were revealed to comprise a minor component of thin pili. Formation of PilV-specific cell aggregates by ColIb-P9 and R64 thin pili was demonstrated and may play an important role in liquid mating.

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