Cytoplasmic DNA is structurally different from nuclear DNA

1983 ◽  
Vol 70 (5) ◽  
pp. 252-254 ◽  
Author(s):  
J. Koch ◽  
G. Vogt ◽  
W. Kissel
Keyword(s):  
Nuclear Dna ◽  
Cytoplasmic Dna

scholarly journals NUCLEAR DNA AND CYTOPLASMIC DNA FROM TISSUES OF HIGHER PLANTS

1965 ◽  
Vol 27 (3) ◽  
pp. 451-457 ◽  
Author(s):  
Yasuo Hotta ◽  
Alix Bassel ◽  
Herbert Stern
Keyword(s):  
Inorganic Phosphate ◽  
Nuclear Dna ◽  
Higher Plants ◽  
Soluble Fraction ◽  
Buoyant Density ◽  
Wheat Roots ◽  
Cytoplasmic Dna ◽  
Sucrose Medium

Young wheat roots were labeled with 32P-inorganic phosphate. Following the labeling period, roots were homogenized in a sucrose medium and fractionated into nuclei, cytoplasmic particles (including proplastids and mitochondria), and a soluble fraction containing most of the microsomes. DNA prepared from the particles had a higher buoyant density than that from the nuclei and showed a marked loss in total label if the roots were exposed to non-radioactive medium for 48 hours prior to fractionation of the cells.

The Gene and Gene Expression (GAGE) Species Concept: An Universal Approach for All Eukaryotic Organisms

2020 ◽  
Vol 69 (5) ◽  
pp. 1033-1038
Author(s):  
Bernhard Seifert
Keyword(s):  
Gene Expression ◽  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Nuclear Dna ◽  
Species Concept ◽  
Cluster Formation ◽  
Reticulate Evolution ◽  
Evolutionary Divergence ◽  
Character System ◽  
Cytoplasmic Dna

Abstract The Gene and Gene Expression (GAGE) species concept, a new version of the Pragmatic Species Concept of Seifert (2014), is proposed as a concept applicable to any described recent or fossil eukaryotic organism independent from its mode of reproduction or evolutionary history. In addition to presenting the concept as such, the article also provides practical recommendations for taxonomists when delimiting species and describing taxa. The wording of the new concept contains a heading core sentence plus five attached sentences addressing essential conditions for its translation into a sound taxonomic practice: “Species are separable clusters that have passed a threshold of evolutionary divergence and are exclusively defined by nuclear DNA sequences and/or their expression products. Nuclear DNA sequences and their expression products are different character systems but have a highly correlated indicative function. Character systems with the least risk of epigenetic or ontogenetic modification have superior indicative value when conflicts between character systems of integrative studies arise. All character systems have to be described by an adequate numerics allowing cluster formation and determination of thresholds. Thresholds for each character system should be fixed by consensus among the experts under the principle of avoiding oversplitting or lumping. Clusters must not be the expression of intraspecific polymorphism.” Recognizing the distortions and conflicts caused to taxonomy through barcoding or through assessment on the basis of association with other organisms, the GAGE species concept strongly downgrades the use of cytoplasmic DNA of endosymbiotic origin (mtDNA, cpDNA) or DNA of closely associated microbes (e.g., Wolbachia bacteria) for final taxonomic decision-making. Recognizing the distortion of phylogenies by the high frequency of reticulate evolution, it is argued that delimiting and naming species has to be separated from constructing bifurcating phylogenetic trees. [Cytoplasmic DNA; lumping; nuclear DNA; numeric taxonomy; oversplitting; reticulate evolution.]

scholarly journals EVIDENCE FOR CYTOPLASMIC DNA IN ROOT CELLS OF NICOTIANA

1965 ◽  
Vol 24 (2) ◽  
pp. 267-276 ◽  
Author(s):  
Effat Badr Mourad
Keyword(s):  
Actinomycin D ◽  
Nuclear Dna ◽  
Root Cultures ◽  
Cytoplasmic Fraction ◽  
Root Tips ◽  
High Concentration ◽  
Root Cells ◽  
Cytoplasmic Component ◽  
Cytoplasmic Dna ◽  
Measurable Rate

Sterile root cultures from Nicotiana tabacum were grown with H3-thymidine added to the medium for various intervals. Incorporation of the labeled nucleoside into nuclear DNA occurred in a fraction of the nuclei which increased with time. In addition, the cytoplasm of all cells incorporated enough tritium to be readily detected by autoradiography. The tritium was not removed by hydrolysis in 1 N HCl at 60°C for 10 minutes, but was removed by digestion in a DNase solution which also removed nuclear DNA. The amount of tritium in the cytoplasm increased during the first 2 hours, but did not appear to increase significantly during the following 5 hours. If the roots were transferred to unlabeled medium after 2 hours, the label was diluted faster than expected by growth without turnover of the labeled component. If FUdR was added to the unlabeled medium, the depletion occurred faster during the first 6 hours, but later appeared to level off so that at 10 hours these cultures did not differ from those incubated without FUdR. However, the addition of an excess of unlabeled carrier had no effect on the rate of depletion of the cytoplasmic label. Actinomycin D, which inhibited the incorporation of H3-cytidine into RNA in the root tips, had no effect on the incorporation of H3-thymidine into the cytoplasmic component. However, Mitomycin C or a high concentration of deoxyadenosine inhibited the incorporation of H3-thymidine into the cytoplasmic component as well as into the nuclear DNA. It is concluded that H3-thymidine is incorporated into a cytoplasmic fraction which has the characteristics of DNA, with a measurable rate of turnover. This fraction is synthesized regardless of whether or not the nucleus is synthesizing DNA. Although the function of cytoplasmic fraction is not yet known, it does not appear to be that of supplying precursors for the synthesis of the nuclear DNA.

scholarly journals Nuclear and Cytoplasmic DNA Sequence Data Further Illuminate the Genetic Composition of Leyland Cypresses

2014 ◽  
Vol 139 (5) ◽  
pp. 558-566 ◽  
Author(s):  
Yi-Xuan Kou ◽  
Hui-Ying Shang ◽  
Kang-Shan Mao ◽  
Zhong-Hu Li ◽  
Keith Rushforth ◽  
...  
Keyword(s):  
Nuclear Dna ◽  
Sequence Data ◽  
Mt Dna ◽  
Future Studies ◽  
Dna Sequence Data ◽  
The United Kingdom ◽  
Cytoplasmic Dna ◽  
History Of ◽  
Evergreen Conifer ◽  
Fertile Hybrids

Leyland cypress [×Hesperotropsis leylandii (A.B. Jacks. & Dallim.) Garland & G. Moore, Cupressaceae] is a well-known horticultural evergreen conifer in the United Kingdom, United States, Australia, New Zealand, and other countries. As demonstrated by previous studies, this taxon is a hybrid between alaska (nootka) cypress [Callitropsis nootkatensis (D. Don) Oerst. ex D.P. Little] and monterey cypress [Hesperocyparis macrocarpa (Hartw. ex Gordon) Bartel]. However, the genetic background of leyland cypress cultivars is unclear. Are they F1 or F2 hybrids or backcrosses? In this study, six individuals that represent major leyland cypress cultivars and two individuals each of its two putative parental species were collected, and three nuclear DNA regions (internal transcribed spacer, leafy and needly), three mitochondrial (mt) DNA regions (coxI, atpA, and rps3), and two chloroplast (cp) DNA regions (matK and rbcL) were sequenced and analyzed. Sequencing results of nuclear DNA regions revealed that leyland cypress cultivars consist of putative F1 and F2 hybrids as well as backcrosses. Analysis of the cp and mt DNA from six cultivars of leyland cypress revealed that their cytoplasmic (cp and mt) genomes came from alaska cypress. Our findings will provide important instructions and background knowledge on the management of these major leyland cypress cultivars as well as future studies. Meanwhile, alaska cypress and monterey cypress may have diverged with each other ≈46 million years ago. The fact that they can produce fertile hybrids indicates that hybridization events may have played an important role in the evolutionary history of the cypress family (Cupressaceae).

scholarly journals Observations on ultracentrifuging wild-type and mutant (cdc2.33) cells of Schizosaccharomyces pombe

1989 ◽  
Vol 92 (3) ◽  
pp. 345-348
Author(s):  
A. Khar ◽  
J.M. Mitchison
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Nuclear Dna ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Intense Fluorescence ◽  
Cytoplasmic Dna ◽  
Dnase Treatment

Ultracentrifuging (400,000 g for 4–6 h at 4 degrees C) living wild-type cells of the fission yeast Schizosaccharomyces pombe moves the nucleus towards the ends of the cells but scarcely affects their viability. However, in the long cells produced by growing the mutant cdc2.33 for 4–6 h at the restrictive temperature (36.5 degrees C), ultracentrifuging (as above) gives an intense fluorescence with DAPI in about half of the cytoplasm in about 80% of the cells. This is probably nuclear DNA that has moved into the cytoplasm, both because of the DAPI stain and because it is removed by DNase treatment. These cells ultimately divide and are viable, and we suggest that the extended cytoplasmic DNA returns to the nucleus.

Replication of Macronuclear DNA in the Cytoplasm of Tetrahymena Pyriformis

1974 ◽  
Vol 14 (2) ◽  
pp. 289-300
Author(s):  
H. A. ANDERSEN
Keyword(s):  
Cell Division ◽  
Dna Replication ◽  
Nuclear Dna ◽  
Tetrahymena Pyriformis ◽  
Cell Generation ◽  
The Other ◽  
Previous Generation ◽  
Cytoplasmic Dna ◽  
Continue Growth ◽  
S Period

Previous experiments showed that a synchronous population of Tetrahymena could divide even though DNA replication was blocked during the latter half of the preceding S-period by addition of methotrexate plus uridine (M + U). Furthermore, it was found that the DNA fraction which was in replication at the time of inhibition became localized in the cytoplasm following elimination from the nucleus at the time of division. When the inhibitory treatment (M + U) was removed prior to or at the time of the cell division the cells were found to engage in new DNA replication and continue growth. Two questions arose from these studies. First, is the DNA replication normal following release from M + U? Second, what is the fate of the cytoplasmic DNA? In the present paper DNA replication has been studied using incorporation of 5-bromodeoxyuridine and centrifugation of the labelled DNA in CsCl gradients. It is concluded that the DNA which finished replication prior to the effect of the M + U treatment replicates again during the S-period of the next cell generation. On the other hand, the DNA fraction which was stalled in replication and subsequently eliminated from the nucleus also replicates in the cytoplasm in the next generation but during G2 period, out of phase with the undamaged nuclear DNA. The cytoplasmic DNA replication appeared to be a continuation of the replication initiated in the nucleus in the previous generation.

A rare moss Cynodontium suecicum (Rhabdoweisiaceae, Bryophyta) on the Barents Sea coast of the Kola Peninsula: morphological and molecular study

2021 ◽  
Vol 55 (2) ◽  
pp. 427-438
Author(s):  
O. A. Belkina ◽  
A. A. Vilnet
Keyword(s):  
Kola Peninsula ◽  
Nuclear Dna ◽  
Barents Sea ◽  
Sequence Data ◽  
Molecular Study ◽  
Nucleotide Sequence Data ◽  
The Barents Sea ◽  
Cytoplasmic Dna ◽  
The Stability ◽  
Sea Coast

Specimens of the rare species Cynodontium suecicum (Rhabdoweisiaceae, Bryophyta) were collected near Drozdovka Bay on the Barents Sea coast of the Kola Peninsula (Russia) in 2016. They were compared with samples of C. suecicum from the Teriberka area (also the coast of the Barents Sea) gathered in 1977 by R. N. Schljakov. The morphological features of both groups of samples were studied, and nucleotide sequence data for ITS1-2 nrDNA and trnL-F cpDNA were obtained. Molecular analysis suggested C. suecicum as a hybrid that inherited cytoplasmic DNA from C. tenellum and nuclear DNA from Kiaeria blyttii. Taking into account the rather clear morphological delimitation against other species, combined with the stability of genetic characters, we believe that S. suecicum should be retained as a species-level taxon.

scholarly journals Exosomes maintain cellular homeostasis by excreting harmful DNA from cells

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Akiko Takahashi ◽  
Ryo Okada ◽  
Koji Nagao ◽  
Yuka Kawamata ◽  
Aki Hanyu ◽  
...  
Keyword(s):  
Dna Damage Response ◽  
Nuclear Dna ◽  
Innate Immune ◽  
Oxygen Species ◽  
Chromosomal Dna ◽  
Cellular Homeostasis ◽  
Cycle Arrest ◽  
Cytoplasmic Dna ◽  
Damage Response ◽  
Normal Human

Abstract Emerging evidence is revealing that exosomes contribute to many aspects of physiology and disease through intercellular communication. However, the biological roles of exosome secretion in exosome-secreting cells have remained largely unexplored. Here we show that exosome secretion plays a crucial role in maintaining cellular homeostasis in exosome-secreting cells. The inhibition of exosome secretion results in the accumulation of nuclear DNA in the cytoplasm, thereby causing the activation of cytoplasmic DNA sensing machinery. This event provokes the innate immune response, leading to reactive oxygen species (ROS)-dependent DNA damage response and thus induce senescence-like cell-cycle arrest or apoptosis in normal human cells. These results, in conjunction with observations that exosomes contain various lengths of chromosomal DNA fragments, indicate that exosome secretion maintains cellular homeostasis by removing harmful cytoplasmic DNA from cells. Together, these findings enhance our understanding of exosome biology, and provide valuable new insights into the control of cellular homeostasis.

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