Induction of DNA replication in germinal vesicles and in nuclei formed in maturing mouse oocytes by 6-DMAP treatment

Zygote ◽  
1997 ◽  
Vol 5 (3) ◽  
pp. 213-217 ◽  
Author(s):  
J. Fulka ◽  
N.L. First ◽  
C. Lee ◽  
J. Fulka ◽  
R.M. Moor
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Germinal Vesicle ◽  
The Other ◽  
Immature Oocytes ◽  
Mouse Oocytes ◽  
Germinal Vesicles ◽  
Immature Mouse ◽  
Condensed Dna ◽  
Metaphase Ii Oocytes

SummaryImmature mouse oocytes (germinal vesicle stage, GV), oocytes at different stages during maturation (prometaphase to anaphase I) and matured oocytes (metaphase II arrested) were cultured in 6-dimethylaminopurine (6-DMAP)-supplemented medium also containing bromodeoxyuridine for the assessment of DNA replication in these cells. Immature oocytes remained arrested at the GV stage and DNA replication was never detected in them. On the other hand, oocytes at the prometaphase to anaphase-telophase I stages responded to 6-DMAP treatment by forming nuclei which synthesised DNA. Mature (metaphase II) oocytes did not respond to 6-DMAP and their chromatin remained condensed. DNA synthesis could even be induced in GV-staged oocytes, but only when they were fused to freshly activated oocytes and incubated in 6-DMAP-supplemented medium.

scholarly journals Distribution of mitochondria in reconstructed mouse oocytes

Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Helena Fulka
Keyword(s):  
Cell Cycle ◽  
Mitochondrial Dna ◽  
Germinal Vesicle ◽  
Model Experiments ◽  
Mouse Oocytes ◽  
Immature Mouse ◽  
Cycle Dependent

It has been suggested that nucleus replacement (transfer) may be used as an efficient oocyte therapy in order to prevent transmission of mutated mitochondrial DNA from mother to offspring in humans. The essential and not yet answered question is how mitochondria surrounding the karyoplast will be distributed in the newly reconstructed oocytes. In our model experiments, we have evaluated the distribution of mitochondria in reconstructed immature mouse oocytes when germinal vesicle karyoplasts, with labeled mitochondria, were fused to unlabeled cytoplasts. The penetration of mitochondria from karyoplasts into cytoplasts can be detected almost immediately after the beginning of fusion. In immature reconstructed oocytes, mitochondria are first located in the oocyte center but they are homogenously distributed within the whole cytoplasm before the completion of maturation. Fusion of oocytes at different stages of maturation suggests that the speed of mitochondria distribution is cell cycle dependent.

scholarly journals Effect of inhibition of DNA synthesis on mating inEscherichia coliK12

1965 ◽  
Vol 6 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Susan Hollom ◽  
R. H. Pritchard
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Amino Acid Starvation ◽  
The Other ◽  
Thymine Starvation ◽  
Other Hand ◽  
Inhibition Of Dna Synthesis ◽  
Polynucleotide Chain

From studies involving inhibition of DNA synthesis in Hfr strains ofEscherichia coliK12, either by thymine starvation (Pritchard, 1963) or amino-acid starvation (Suit, Matney, Doudney & Billen, 1964), during mating withF−strains, it has been concluded that transfer of DNA from males to females can occur in the absence of DNA synthesis. This conclusion is at variance with the hypothesis (Jacob, Brenner & Cuzin, 1963) that the energy required for transfer is derived from the process of DNA replication. On the other hand, a second prediction from this hypothesis, that one polynucleotide chain of the DNA transferred during mating will have been synthesized during transfer, is strongly supported by recent experiments (Ptashne, 1965; Blinkova, Bresler & Lanzov, 1965; Gross & Caro, 1965).

scholarly journals Active maturation-promoting factor is present in mature mouse oocytes.

1985 ◽  
Vol 100 (5) ◽  
pp. 1637-1640 ◽  
Author(s):  
R A Sorensen ◽  
M S Cyert ◽  
R A Pedersen
Keyword(s):  
Xenopus Oocytes ◽  
Germinal Vesicle ◽  
Xenopus Laevis Oocytes ◽  
Factor Activity ◽  
Dibutyryl Cyclic Amp ◽  
Germinal Vesicle Breakdown ◽  
Mouse Oocytes ◽  
Immature Mouse ◽  
Mature Mouse ◽  
Maturation Promoting Factor

Cytoplasmic extracts of meiotically mature mouse oocytes were injected into immature Xenopus laevis oocytes, which underwent germinal vesicle breakdown within 2 h. Germinal vesicle breakdown was not inhibited by incubation of the Xenopus oocytes in cycloheximide (20 micrograms/ml). Identically prepared extracts of meiotically immature mouse oocytes, arrested at the germinal vesicle stage by dibutyryl cyclic AMP (100 micrograms/ml), did not induce germinal vesicle breakdown in Xenopus oocytes. The results show that maturation-promoting factor activity appears during the course of oocyte maturation in the mouse.

Germinal Vesicle Transfer Between Fresh and Cryopreserved Immature Mouse Oocytes

2000 ◽  
Vol 74 (3) ◽  
pp. S47-S48
Author(s):  
F Comoglio ◽  
F Moffa ◽  
H Liu ◽  
J.A Grifo ◽  
L.C Krey ◽  
...  
Keyword(s):  
Germinal Vesicle ◽  
Mouse Oocytes ◽  
Immature Mouse

Effect of C-type natriuretic peptide on maturation and developmental competence of immature mouse oocytes in vitro

2017 ◽  
Vol 29 (2) ◽  
pp. 319 ◽  
Author(s):  
Qiang Wei ◽  
Chuan Zhou ◽  
Min Yuan ◽  
Yuyang Miao ◽  
Xiaoe Zhao ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Oocyte Maturation ◽  
Subsequent Development ◽  
Developmental Competence ◽  
Meiotic Arrest ◽  
Immature Oocytes ◽  
Mouse Oocytes ◽  
Immature Mouse ◽  
Cytoplasmic Maturation

In vitro maturation (IVM) of oocytes is an important assisted reproductive technology for infertility treatment and livestock breeding programs. Because of asynchronous nuclear and cytoplasmic maturation, the developmental competence of oocytes matured in vitro is compromised. C-Type natriuretic peptide (CNP), which has been proved to be an inhibitor of oocyte maturation, provides a new alternative to optimise synchronisation of nuclear and cytoplasmic maturation and improve developmental capacity of immature oocytes in vitro. To investigate the effect of temporary meiotic arrest mediated by CNP on maturation and subsequent development of immature oocytes, immature mouse oocytes from small antral follicles were temporarily arrested in meiosis by CNP (0, 5, 10 and 50 nM) for 24 h and then matured for 16 h. CNP treatment significantly increased the oocyte maturation rate from less than half to above 80%. After IVF, temporary meiotic arrest mediated by 10 and 50 nM CNP significantly improved fertilisation and blastocyst rate of oocytes matured in vitro up to approximately 55% and 30% respectively. Moreover, this positive effect of CNP was attributed, in part, to an increase in the number of mature oocytes with aligned chromosomes and a normal spindle. The present findings indicate the potential to use CNP to improve the efficiency of oocyte IVM.

scholarly journals Histone H3 Lysine 4 Methylation Marks Postreplicative Human Cytomegalovirus Chromatin

2012 ◽  
Vol 86 (18) ◽  
pp. 9817-9827 ◽  
Author(s):  
Alexandra Nitzsche ◽  
Charlotte Steinhäußer ◽  
Katrin Mücke ◽  
Christina Paulus ◽  
Michael Nevels
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Histone Modification ◽  
Dna Polymerase ◽  
Human Cytomegalovirus ◽  
Viral Genome ◽  
Histone H3 ◽  
Viral Dna ◽  
The Impact ◽  
Preferential Incorporation

In the nuclei of permissive cells, human cytomegalovirus genomes form nucleosomal structures initially resembling heterochromatin but gradually switching to a euchromatin-like state. This switch is characterized by a decrease in histone H3 K9 methylation and a marked increase in H3 tail acetylation and H3 K4 methylation across the viral genome. We used ganciclovir and a mutant virus encoding a reversibly destabilized DNA polymerase to examine the impact of DNA replication on histone modification dynamics at the viral chromatin. The changes in H3 tail acetylation and H3 K9 methylation proceeded in a DNA replication-independent fashion. In contrast, the increase in H3 K4 methylation proved to depend widely on viral DNA synthesis. Consistently, labeling of nascent DNA using “click chemistry” revealed preferential incorporation of methylated H3 K4 into viral (but not cellular) chromatin during or following DNA replication. This study demonstrates largely selective epigenetic tagging of postreplicative human cytomegalovirus chromatin.

A Requirement for Recombinational Repair in Saccharomyces cerevisiae Is Caused by DNA Replication Defects of mec1 Mutants

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 595-605 ◽  
Author(s):  
Bradley J Merrill ◽  
Connie Holm
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Synthetic Lethality ◽  
Velocity Sedimentation ◽  
Recombinational Repair ◽  
Repair Pathway ◽  
Dna Breaks ◽  
Single Stranded Dna ◽  
Double Stranded Dna

Abstract To examine the role of the RAD52 recombinational repair pathway in compensating for DNA replication defects in Saccharomyces cerevisiae, we performed a genetic screen to identify mutants that require Rad52p for viability. We isolated 10 mec1 mutations that display synthetic lethality with rad52. These mutations (designated mec1-srf for synthetic lethality with rad-fifty-two) simultaneously cause two types of phenotypes: defects in the checkpoint function of Mec1p and defects in the essential function of Mec1p. Velocity sedimentation in alkaline sucrose gradients revealed that mec1-srf mutants accumulate small single-stranded DNA synthesis intermediates, suggesting that Mec1p is required for the normal progression of DNA synthesis. sml1 suppressor mutations suppress both the accumulation of DNA synthesis intermediates and the requirement for Rad52p in mec1-srf mutants, but they do not suppress the checkpoint defect in mec1-srf mutants. Thus, it appears to be the DNA replication defects in mec1-srf mutants that cause the requirement for Rad52p. By using hydroxyurea to introduce similar DNA replication defects, we found that single-stranded DNA breaks frequently lead to double-stranded DNA breaks that are not rapidly repaired in rad52 mutants. Taken together, these data suggest that the RAD52 recombinational repair pathway is required to prevent or repair double-stranded DNA breaks caused by defective DNA replication in mec1-srf mutants.

Sign in / Sign up

Export Citation Format

Share Document