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.

scholarly journals Effects of 5-bromodeoxyuridine on the ACTH-dependent mitochondrial biogenesis in cortical cells of fetal rat adrenals in tissue culture.

1976 ◽  
Vol 71 (3) ◽  
pp. 951-956 ◽  
Author(s):  
A I Kahri ◽  
M Salmenperä ◽  
A Saure
Keyword(s):  
Tissue Culture ◽  
Mitochondrial Dna ◽  
Dna Synthesis ◽  
Nuclear Dna ◽  
Acth Stimulation ◽  
Cortical Cells ◽  
Proliferative Phase ◽  
Fetal Rat ◽  
Rat Adrenals ◽  
Mitochondrial Dna Synthesis

Cortical cells of fetal rat adrenals in tissue culture were treated with 5-bromodeoxyuridine (BrdU) during their proliferative phase and during ACTH stimulation when nuclear DNA synthesis has almost ceased. Pretreatment with 0.5 mug/ml/day of BrdU inhibited the ACTH-induced differentiation of cortical cells as well as the secretion of corticosterone and 18-OH-deoxycorticosterone (18-OHDOC). When nuclear DNA synthesis was suppressed and mitochondrial DNA synthesis was stimulated by ACTH BrdU addition (30 mug/ml/day) permitted normal untrastructural differentiation of cortical cells, except that the development of mitochondrial inner membranes was inhibited. Simultaneously mitochondrial inner membranes was inhibited. Simultaneously mitochondrial 11beta- and 18-hydroxylations were strongly inhibited while cytoplasmic 21-hydroxylation was not affected.

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.

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.

Identification of temperature-sensitive DNA- mutants of Chinese hamster cells affected in cellular and viral DNA synthesis

1986 ◽  
Vol 6 (12) ◽  
pp. 4594-4601
Author(s):  
J J Dermody ◽  
B E Wojcik ◽  
H Du ◽  
H L Ozer
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Chinese Hamster ◽  
Human Adenovirus ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Dependent Manner ◽  
Viral Dna ◽  
Cell Functions

We described a strategy which facilitates the identification of cell mutants which are restricted in DNA synthesis in a temperature-dependent manner. A collection of over 200 cell mutants temperature-sensitive for growth was isolated in established Chinese hamster cell lines (CHO and V79) by a variety of selective and nonselective techniques. Approximately 10% of these mutants were identified as ts DNA- based on differential inhibition of macromolecular synthesis at the restrictive temperature (39 degrees C) as assessed by incorporation of [3H]thymidine and [35S]methionine. Nine such mutants, selected for further study, demonstrated rapid shutoff of DNA replication at 39 degrees C. Infections with two classes of DNA viruses extensively dependent on host-cell functions for their replication were used to distinguish defects in DNA synthesis itself from those predominantly affecting other aspects of DNA replication. All cell mutants supported human adenovirus type 2 (Ad2) and mouse polyomavirus DNA synthesis at the permissive temperature. Five of the nine mutants (JB3-B, JB3-O, JB7-K, JB8-D, and JB11-J) restricted polyomavirus DNA replication upon transfection with viral sequences at 33 degrees C and subsequent shift to 39 degrees C either before or after the onset of viral DNA synthesis. Only one of these mutants (JB3-B) also restricted Ad2 DNA synthesis after virion infection under comparable conditions. No mutant was both restrictive for Ad2 and permissive for polyomavirus DNA synthesis at 39 degrees C. The differential effect of these cell mutants on viral DNA synthesis is expected to assist subsequent definition of the biochemical defect responsible.

scholarly journals Influence of hydroxyurea on the course of germination and growth of rape (Brasica napus L.) seedlings

2015 ◽  
Vol 47 (1–2) ◽  
pp. 131-141 ◽  
Author(s):  
M. Kuraś ◽  
H. Teleżyński
Keyword(s):  
Mitochondrial Dna ◽  
Root Growth ◽  
Dna Synthesis ◽  
Elongation Growth ◽  
Complete Inhibition ◽  
Hypocotyl Growth ◽  
Prolonged Incubation ◽  
Inhibition Of Growth ◽  
Germination And Growth ◽  
Mitochondrial Dna Synthesis

The effects of continuous incubation in hydroxyurea (HU) solutions (0.2, 0.4, 0.8 mg/ml) on germination of rape seeds and growth of young seedling axes were studied during 132 hours from initial soaking. Germination turned out to be unaffected by the treatment. Root growth was first increasingly inhibited by the HU concentration tested, but after prolonged incubation a complete arrest of the root growth was noted at all HU concentrations. The elongation growth of hypocotyls was found to be stimulated by a HU 0.2 mg/ml concentration while it was markedly suppressed by 0.4 mg/ml, and completely arrested by 0.8 mg/ml Inhibition of growth of the upright hypocotyl part at higher HU concentration was found to be accompanied by the unbending of the hooked under-cotyledonary part. It is suggested that inhibition of nuclear endomitotic DNA synthesis In elongating hypocotyl cells, suppresses only partially their growth, whereas a complete inhibition of the hypocotyl growth results from arrest of the mitochondrial DNA synthesis.

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