Non-Random Distribution of Alu-Family DNA Repeats in Human Chromosomes

1990 ◽  
pp. 41-45
Author(s):  
L. V. Filatov ◽  
S. E. Mamayeva ◽  
N. V. Tomilin
Keyword(s):  
Random Distribution ◽  
Dna Repeats ◽  
Human Chromosomes

Non random distribution of lesions induced by deoxyribonuclease I in human chromosomes

1987 ◽  
Vol 1 (1) ◽  
pp. 19-24
Author(s):  
Fiorella Nuzzo ◽  
Alessandra Casati ◽  
Elena Raimondi
Keyword(s):  
Random Distribution ◽  
Human Chromosomes ◽  
Deoxyribonuclease I

Non-random distribution of Alu-family repeats in human chromosomes

1987 ◽  
Vol 12 (2) ◽  
pp. 117-121 ◽  
Author(s):  
L. V. Filatov ◽  
S. E. Mamayeva ◽  
N. V. Tomilin
Keyword(s):  
Random Distribution ◽  
Human Chromosomes

?Conservative? and ?variable? clusters of Alu-family DNA repeats in human chromosomes

1988 ◽  
Vol 13 (2) ◽  
pp. 79-84 ◽  
Author(s):  
L. V. Filatov ◽  
S. E. Mamayeva ◽  
N. V. Tomilin
Keyword(s):  
Dna Repeats ◽  
Human Chromosomes

scholarly journals A single telomerase RNA is sufficient for the synthesis of variable telomeric DNA repeats in ciliates of the genus Paramecium.

1996 ◽  
Vol 16 (4) ◽  
pp. 1871-1879 ◽  
Author(s):  
M McCormick-Graham ◽  
D P Romero
Keyword(s):  
Secondary Structure ◽  
Random Distribution ◽  
Single Gene ◽  
Telomerase Rna ◽  
Paramecium Tetraurelia ◽  
Dna Repeats ◽  
Telomeric Dna ◽  
Telomeric Repeats ◽  
Precise Nature ◽  
Rna Genes

Paramecium telomeric DNA consists largely of a random distribution of TTGGGG and TTTGGG repeats. Given the precise nature of other ciliate telomerases, it has been postulated that there are two distinct types of the Paramecium enzyme, each synthesizing perfect telomeric repeats: one with a template RNA that specifies the addition of TTTGGG and the second dictating the synthesis of TTGGGG repeats. We have cloned and sequenced telomerase RNA genes from Paramecium tetraurelia, P. primaurelia, P. multimicronucleatum, and P. caudatum. Surprisingly, a single gene encodes telomerase RNA in all four species, although an apparently nontranscribed pseudogene is also present in the genome of P. primaurelia. The overall lengths of the telomerase RNAs range between 202 and 209 nucleotides, and they can be folded into a conserved secondary structure similar to that derived for other ciliate RNAs. All Paramecium telomerase RNAs examined include a template specific for the synthesis of TTGGGG telomeric repeats, which has not been posttranscriptionally edited to account for the conventional synthesis of TTTGGG repeats. On the basis of these results, possible mechanisms for the synthesis of variable telomeric repeats by Paramecium telomerase are discussed.

Non-Random Distribution of Certain Homologous Pairs of Normal Human Chromosomes in Metaphase

Nature ◽  
1962 ◽  
Vol 195 (4847) ◽  
pp. 1229-1230 ◽  
Author(s):  
LAWRENCE J. SCHNEIDERMAN ◽  
CEDRIC A. B. SMITH
Keyword(s):  
Random Distribution ◽  
Human Chromosomes ◽  
Normal Human

scholarly journals Heat Shock Affects Mitotic Segregation of Human Chromosomes Bound to Stress-Induced Satellite III RNAs

2020 ◽  
Vol 21 (8) ◽  
pp. 2812
Author(s):  
Manuela Giordano ◽  
Lucia Infantino ◽  
Marco Biggiogera ◽  
Alessandra Montecucco ◽  
Giuseppe Biamonti
Keyword(s):  
Heat Shock ◽  
Chromosome Segregation ◽  
Small Rnas ◽  
Chromosomal Instability ◽  
Chromosome 9 ◽  
Dna Repeats ◽  
Human Chromosomes ◽  
Chromosome Behavior ◽  
Argonaute 2 ◽  
Transcription Sites

Heat shock activates the transcription of arrays of Satellite III (SatIII) DNA repeats in the pericentromeric heterochromatic domains of specific human chromosomes, the longest of which is on chromosome 9. Long non-coding SatIII RNAs remain associated with transcription sites where they form nuclear stress bodies or nSBs. The biology of SatIII RNAs is still poorly understood. Here, we show that SatIII RNAs and nSBs are detectable up to four days after thermal stress and are linked to defects in chromosome behavior during mitosis. Heat shock perturbs the execution of mitosis. Cells reaching mitosis during the first 3 h of recovery accumulate in pro-metaphase. During the ensuing 48 h, this block is no longer detectable; however, a significant fraction of mitoses shows chromosome segregation defects. Notably, most of lagging chromosomes and chromosomal bridges are bound to nSBs and contain arrays of SatIII DNA. Disappearance of mitotic defects at the end of day 2 coincides with the processing of long non-coding SatIII RNAs into a ladder of small RNAs associated with chromatin and ranging in size from 25 to 75 nt. The production of these molecules does not rely on DICER and Argonaute 2 components of the RNA interference apparatus. Thus, massive transcription of SatIII DNA may contribute to chromosomal instability.

Random isn't real: How the patchy distribution of ecological rewards may generate “incentive hope”

2019 ◽  
Vol 42 ◽  
Author(s):  
Laurel Symes ◽  
Thalia Wheatley
Keyword(s):  
Natural Environment ◽  
Random Distribution ◽  
Spatiotemporal Distribution ◽  
Patchy Distribution ◽  
Distribution Of Resources

AbstractAnselme & Güntürkün generate exciting new insights by integrating two disparate fields to explain why uncertain rewards produce strong motivational effects. Their conclusions are developed in a framework that assumes a random distribution of resources, uncommon in the natural environment. We argue that, by considering a realistically clumped spatiotemporal distribution of resources, their conclusions will be stronger and more complete.

Organisation in the Structure of the Cytoplasmic Ground Substance

1978 ◽  
Vol 36 (3) ◽  
pp. 627-639
Author(s):  
K.R. Porter
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Random Distribution ◽  
Ground Substance ◽  
The Matrix ◽  
Cell Processes ◽  
Cytoplasmic Ground Substance

Most types of cells are known from their structure and overall form to possess a characteristic organization. In some instances this is evident in the non-random disposition of organelles and such system subunits as cisternae of the endoplasmic reticulum or the Golgi complex. In others it appears in the distribution and orientation of cytoplasmic fibrils. And in yet others the organization finds expression in the non-random distribution and orientation of microtubules, especially as found in highly anisometric cells and cell processes. The impression is unavoidable that in none of these cases is the organization achieved without the involvement of the cytoplasmic ground substance (CGS) or matrix. This impression is based on the fact that a matrix is present and that in all instances these formed structures, whether membranelimited or filamentous, are suspended in it. In some well-known instances, as in arrays of microtubules which make up axonemes and axostyles, the matrix resolves itself into bridges (and spokes) between the microtubules, bridges which are in some cases very regularly disposed and uniform in size (Mcintosh, 1973; Bloodgood and Miller, 1974; Warner and Satir, 1974).

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

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