scholarly journals Mitochondrial growth and DNA synthesis occur in the absence of nuclear DNA replication in fission yeast

1990 ◽  
Vol 97 (3) ◽  
pp. 509-516 ◽  
Author(s):  
S. Sazer ◽  
S.W. Sherwood
Keyword(s):  
Mitochondrial Dna ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Fission Yeast ◽  
Dna Content ◽  
Nuclear Dna ◽  
Equal Distribution ◽  
Daughter Cells ◽  
Mitochondrial Dna Content ◽  
Mitochondrial Volume

Cell growth and division require the doubling of cellular constituents followed by their equal distribution to the two daughter cells. Within a growing population, the ratio of mitochondrial to cellular volume is maintained, as is the number of mitochondrial genomes per cell. The mechanisms responsible for coordinating nuclear and mitochondrial DNA synthesis, and for balancing increases in cell and mitochondrial size are not well understood. In studies of the fission yeast Schizosaccharomyces pombe we quantified cellular and mitochondrial DNA content by both Southern blot analysis and flow cytometry of cells stained with a variety of DNA-binding fluorochromes, which we show are able to detect nuclear and mitochondrial DNA with different efficiencies. In the conditional cell division cycle mutant cdc10, which is unable to initiate nuclear DNA synthesis, we found that there was an increase in the mitochondrial DNA content in the absence of nuclear DNA replication. This demonstrates that mitochondrial and nuclear DNA synthesis are not obligately linked. We also show that mitochondrial DNA replication is not required for the increase in mitochondrial size that occurs as cells elongate, although this results in a decrease in the ratio of mitochondrial DNA to mitochondrial volume.

Mitochondrial DNA synthesis in mouse L cells temperature sensitive in nuclear DNA replication

1977 ◽  
Vol 55 (5) ◽  
pp. 543-547 ◽  
Author(s):  
Rose Sheinin ◽  
Pamela Darragh ◽  
Margaret Dubsky
Keyword(s):  
Mitochondrial Dna ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Nuclear Dna ◽  
Temperature Sensitive ◽  
Chromosomal Dna ◽  
Mt Dna ◽  
L Cells ◽  
Mitochondrial Dna Synthesis

Temperature-sensitive (ts) A1S9 mouse L cells continue to synthesize double-stranded covalently closed mitochondrial (mt) DNA at a temperature (38.5 °C) which is nonpermissive for chromosomal DNA replication. The amount of mt DNA made appears to be quantitatively linked to nuclear DNA synthesis. Nuclear DNA replication proceeds normally for 6–8 h after the cells are shifted to 38.5 °C, and then declines to reach a minimum at 20–24 h. The level of mt DNA synthesis remains high during this period and decreases once the ts lesion has been established.

Periodic expression of nuclear and mitochondrial DNA replication genes during the trypanosomatid cell cycle

1994 ◽  
Vol 107 (12) ◽  
pp. 3515-3520
Author(s):  
S.G. Pasion ◽  
G.W. Brown ◽  
L.M. Brown ◽  
D.S. Ray
Keyword(s):  
Cell Cycle ◽  
Mitochondrial Dna ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Cell Cycle Progression ◽  
Nuclear Dna ◽  
Protein A ◽  
Mrna Levels ◽  
Gene Encoding ◽  
Genes Encoding

In trypanosomatids, DNA replication in the nucleus and in the single mitochondrion (or kinetoplast) initiates nearly simultaneously, suggesting that the DNA synthesis (S) phases of the nucleus and the mitochondrion are coordinately regulated. To investigate the basis for the temporal link between nuclear and mitochondrial DNA synthesis phases the expression of the genes encoding DNA ligase I, the 51 and 28 kDa subunits of replication protein A, dihydrofolate reductase and the mitochondrial type II topoisomerase were analyzed during the cell cycle progression of synchronous cultures of Crithidia fasciculata. These DNA replication genes were all expressed periodically, with peak mRNA levels occurring just prior to or at the peak of DNA synthesis in the synchronized cultures. A plasmid clone (pdN-1) in which TOP2, the gene encoding the mitochondrial topoisomerase, was disrupted by the insertion of a NEO drug-resistance cassette was found to express both a truncated TOP2 mRNA and a truncated topoisomerase polypeptide. The truncated mRNA was also expressed periodically coordinate with the expression of the endogenous TOP2 mRNA indicating that cis elements necessary for periodic expression are contained within cloned sequences. The expression of both TOP2 and nuclear DNA replication genes at the G1/S boundary suggests that regulated expression of these genes may play a role in coordinating nuclear and mitochondrial S phases in trypanosomatids.

Development of matured hiPSCs-derived 3D cardiac tissue using ERR gamma agonist and mechanical stress and application for Hypertrophic Cardiomyopathy (HCM) model

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Fujiwara ◽  
K Deguchi ◽  
Y Naka ◽  
M Sasaki ◽  
T Nishimoto ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Hypertrophic Cardiomyopathy ◽  
Mechanical Stress ◽  
Cell Size ◽  
Dna Content ◽  
Disease Model ◽  
Heart Tissue ◽  
Funding Source ◽  
Mitochondrial Dna Content ◽  
Mechanical Stretching

Abstract Introduction Tissue engineering using human induced pluripotent stem cells-derived cardiomyocytes (hiPSCs-CMs) is one of the potential tools to replicate human heart in vitro. Although there are many publications on 3 dimensional (3D) heart tissues (1), these tissues show fetal like phenotypes. For that reason, several maturation methods such as electrical stimulation and mechanical stress have been investigated (2, 3). However, these methods have been inadequate in differentiating fetal like phenotype tissue from adult tissues. Previously, we identified a novel compound, T112, which induced hiPSCs-CMs maturation from approximately 9,000 compounds using Troponin I1-EmGFP and Troponin I3-mCherry double reporter hiPSCs-CMs. This compound enhanced morphological and metabolic maturation of hiPSCs-CMs via estrogen-rerated receptor gamma activation Purpose We hypothesized that our novel compound, T112, in combination with mechanical stress could result in further maturation of 3D heart tissue. Therefore, our specific aim is to develop a novel maturation method applicable to genetic disease model of HCM using 3D heart tissue combined with T112. Methods We constructed 3D heart tissue mixed with fibroblast and double reporter hiPSCs-CMs by the hydrogel methods using Flex cell system®. We added T112 with or without mechanical stretching to 3D tissue from 7 to 15 days after 3D heart tissue was constructed. Then we measured maturation related phenotype such as sarcomere gene expression, mitochondrial DNA content and cell size. Results Similar to hiPSCs-CM, the addition of T112 to the constructed 3D heart tissue significantly increased TNNI3 mRNA compared to that of DMSO. Furthermore, T112 treated 3D heart tissue showed increased cell size and oblong shape. Next, in order to promote more maturation of 3D heart tissue, we performed mechanical stretching with the addition of T112. The combination of T112 with mechanical stretching showed higher expression of mCherry, a reporter protein for TNNI3 expression, and higher isotropy of sarcomere alignment in 3D heart tissue than that with the static condition. Furthermore, 3D heart tissue in the treatment of T112 with or without mechanical stretching showed higher mitochondrial DNA content compared to the respective DMSO controls. Interestingly, we applied this combination method to hiPSCs carrying MYH7 R719Q mutation which is known to cause hypertrophic cardiomyopathy, and the 3D heart tissue composed of cardiomyocytes derived from mutant iPSCs demonstrated increased sarcomere disarray compared to isogenic wild-type 3D heart tissue. Conclusion These results suggest that the combination of T112 and mechanical stretching promotes metabolic and structural maturation of 3D heart tissue and would be useful for creating a HCM disease model. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): T-CiRA project, Takeda Pharmaceutical Company Limited

scholarly journals Low Tumor Mitochondrial DNA Content Is Associated with Better Outcome in Breast Cancer Patients Receiving Anthracycline-Based Chemotherapy

2017 ◽  
Vol 23 (16) ◽  
pp. 4735-4743 ◽  
Author(s):  
Marjolein J.A. Weerts ◽  
Antoinette Hollestelle ◽  
Anieta M. Sieuwerts ◽  
John A. Foekens ◽  
Stefan Sleijfer ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mitochondrial Dna ◽  
Cancer Patients ◽  
Dna Content ◽  
Breast Cancer Patients ◽  
Mitochondrial Dna Content

Changes of the DNA content of differentiating and adult macronuclei of the ciliate Loxodes magnus (Karyorelictida)

1980 ◽  
Vol 44 (1) ◽  
pp. 375-394
Author(s):  
N.N. Bobyleva ◽  
B.N. Kudrjavtsev ◽  
I.B. Raikov
Keyword(s):  
Cell Division ◽  
Dna Replication ◽  
Hydrochloric Acid ◽  
Dna Synthesis ◽  
Acid Hydrolysis ◽  
Gene Amplification ◽  
Dna Content

The DNA content of isolated micronuclei, differentiating macronuclei (macronuclear Anlagen), and adult macronuclei of Loxodes magnus was measured cytofluorimetrically in preparations stained with a Schiff-type reagent, auramine-SO2, following hydrochloric acid hydrolysis. The DNA content of the youngest macronuclear Anlagen proved to be the same as that of telophasic micronuclei (2 c). The Anlagen thus differentiate from micronuclei which are still in G1. The quantity of DNA in the macronuclear Anlagen thereafter rises to the 4-c level, simultaneously with DNA replication in the micronuclei which immediately follows mitosis. In non-dividing animals most micronuclei are already in G2. Adult macronuclei here contain on average 1.5 times more DNA than the micronuclei; their DNA content is about 5–6 c (in some individual nuclei, up to 10 c). These data are consistent with autoradiographic evidence indicating a weak DNA synthesis in the macronuclei of Loxodes and make likely the existence of partial DNA replication (e.g. gene amplification) in the macronuclei. The DNA content of adult macronuclei isolated from dividing animals proved to be significantly smaller than that of macronuclei isolated from non-dividing specimens of the same clone. In 3 clones studied, the former value amounted on average to 71–79, 78 and 95% of the latter, respectively. This drop of DNA content cannot be explained by ‘dilution’ of the old macronuclei with newly formed ones. The quantity of DNA in adult macronuclei thus seems to undergo cyclical changes correlated with cytokinesis, despite the fact that, in Loxodes magnus, the macronuclei themselves never divide and are simply segregated at every cell division. The macronuclei of Loxodes can be termed paradiploid or hyperdiploid.

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