scholarly journals Uncoupling of DNA Replication and Centrosome Duplication Cycles Is a Primary Cause of Haploid Instability in Mammalian Somatic Cells

2020 ◽  
Vol 8 ◽  
Author(s):  
Koya Yoshizawa ◽  
Kan Yaguchi ◽  
Ryota Uehara
Keyword(s):  
Dna Replication ◽  
Somatic Cells ◽  
Centrosome Duplication

scholarly journals Uncoordinated centrosome duplication cycle underlies the instability of non-diploid states in mammalian somatic cells

2017 ◽  
Author(s):  
Kan Yaguchi ◽  
Ryo Matsui ◽  
Takahiro Yamamoto ◽  
Yuki Tsukada ◽  
Atsuko Shibanuma ◽  
...  
Keyword(s):  
Dna Replication ◽  
Ploidy Level ◽  
Somatic Cells ◽  
Centrosome Duplication ◽  
Scaling Properties ◽  
Gradual Loss ◽  
Monopolar Spindle ◽  
Ploidy Changes ◽  
Duplication Cycle ◽  
Parthenogenetic Mouse Embryos

AbstractIn animals, somatic cells are usually diploid and are unstable when haploid for unknown reasons. In this study, by comparing isogenic human cell lines with different ploidies, we found frequent centrosome loss specifically in the haploid state, which profoundly contributed to haploid instability through monopolar spindle formation and subsequent mitotic defects. We also found that efficiency of centriole licensing and duplication, but not that of DNA replication, changes proportionally to ploidy level, causing gradual loss or frequent overduplication of centrioles in haploid and tetraploid cells, respectively. Centriole licensing efficiency seemed to be modulated by astral microtubules, whose development scaled with ploidy level, and artificial enhancement of aster formation in haploid cells restored centriole licensing efficiency to diploid levels. Haploid-specific centrosome loss was also observed in parthenogenetic mouse embryos. We propose that incompatibility between the centrosome duplication and DNA replication cycles arising from different scaling properties of these bioprocesses upon ploidy changes, underlies the instability of non-diploid somatic cells in mammals.SummaryYaguchi et al. show that a delay or acceleration of centriole licensing compromises the control of centrosome number in haploid or tetraploid human cells, respectively, suggesting a cellular basis of the instability of non-diploid somatic cells in mammals.

scholarly journals Uncoordinated centrosome cycle underlies the instability of non-diploid somatic cells in mammals

2018 ◽  
Vol 217 (7) ◽  
pp. 2463-2483 ◽  
Author(s):  
Kan Yaguchi ◽  
Takahiro Yamamoto ◽  
Ryo Matsui ◽  
Yuki Tsukada ◽  
Atsuko Shibanuma ◽  
...  
Keyword(s):  
Dna Replication ◽  
Human Cell ◽  
Ploidy Level ◽  
Somatic Cells ◽  
Cell Types ◽  
Centrosome Duplication ◽  
Human Cell Lines ◽  
Scaling Properties ◽  
Gradual Loss ◽  
Ploidy Changes

In animals, somatic cells are usually diploid and are unstable when haploid for unknown reasons. In this study, by comparing isogenic human cell lines with different ploidies, we found frequent centrosome loss specifically in the haploid state, which profoundly contributed to haploid instability through subsequent mitotic defects. We also found that the efficiency of centriole licensing and duplication changes proportionally to ploidy level, whereas that of DNA replication stays constant. This caused gradual loss or frequent overduplication of centrioles in haploid and tetraploid cells, respectively. Centriole licensing efficiency seemed to be modulated by astral microtubules, whose development scaled with ploidy level, and artificial enhancement of aster formation in haploid cells restored centriole licensing efficiency to diploid levels. The ploidy–centrosome link was observed in different mammalian cell types. We propose that incompatibility between the centrosome duplication and DNA replication cycles arising from different scaling properties of these bioprocesses upon ploidy changes underlies the instability of non-diploid somatic cells in mammals.

scholarly journals Uncoupling of DNA replication and centrosome duplication cycles is a primary cause of haploid instability in mammalian somatic cells

2020 ◽  
Author(s):  
Koya Yoshizawa ◽  
Kan Yaguchi ◽  
Ryota Uehara
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Replication ◽  
Genome Instability ◽  
Somatic Cells ◽  
S Phase ◽  
Centrosome Duplication ◽  
Potential Contribution ◽  
Mitotic Control ◽  
The Stability

AbstractMammalian haploid somatic cells are unstable and prone to diploidize, but the cause of haploid instability remains largely unknown. Previously, we found that mammalian haploid somatic cells suffer chronic centrosome loss stemming from the uncoupling of DNA replication and centrosome duplication cycles. However, the lack of methodology to restore the coupling between DNA replication and centrosome duplication has precluded us from investigating the potential contribution of the haploidy-linked centrosome loss to haploid instability. In this study, we developed an experimental method that allows the re-coupling of DNA and centrosome cycles through the chronic extension of the G1/S phase without compromising cell proliferation using thymidine treatment/release cycles. Chronic extension of G1/S restored normal mitotic centrosome number and mitotic control, substantially improving the stability of the haploid state in HAP1 cells. Stabilization of the haploid state was compromised when cdk2 was inhibited during the extended G1/S, or when early G1 was chronically extended instead of G1/S, showing that the coupling of DNA and centrosome cycles rather than a general extension of the cell cycle is required for haploid stability. Our data indicate the chronic centriole loss arising from the uncoupling of centrosome and DNA cycles as a direct cause of genome instability in haploid somatic cells, and also demonstrate the feasibility of modulation of haploid stability through artificial coordination between DNA and centrosome cycles in mammalian somatic cells.

scholarly journals Sufu negatively regulates both initiations of centrosome duplication and DNA replication

2021 ◽  
Vol 118 (28) ◽  
pp. e2026421118
Author(s):  
Tenghan Zhuang ◽  
Boyan Zhang ◽  
Yihong Song ◽  
Fan Huang ◽  
Wangfei Chi ◽  
...  
Keyword(s):  
Dna Replication ◽  
Negative Regulator ◽  
Centrosome Duplication ◽  
Canonical Function ◽  
Multipolar Spindle ◽  
Suppressor Of Fused ◽  
Serum Stimulation ◽  
Gli Proteins ◽  
Origin Licensing ◽  
And Function

Centrosome duplication and DNA replication are two pivotal events that higher eukaryotic cells use to initiate proliferation. While DNA replication is initiated through origin licensing, centrosome duplication starts with cartwheel assembly and is partly controlled by CP110. However, the upstream coordinator for both events has been, until now, a mystery. Here, we report that suppressor of fused protein (Sufu), a negative regulator of the Hedgehog (Hh) pathway playing a significant role in restricting the trafficking and function of glioma-related (Gli) proteins, acts as an upstream switch by facilitating CP110 phosphorylation by CDK2, promoting intranuclear Cdt1 degradation and excluding prereplication complex (pre-RC) components from chromosomes, independent of its canonical function in the Hh pathway. We found that Sufu localizes to both the centrosome and the nucleus and that knockout of Sufu induces abnormalities including centrosome amplification, increased nuclear size, multipolar spindle formation, and polyploidy. Serum stimulation promotes the elimination of Sufu from the centrosome by vesicle release at the ciliary tip and from the nucleus via protein degradation, which allows centrosome duplication and DNA replication to proceed. Collectively, this work reveals a mechanism through which Sufu negatively regulates the G1-S transition.

121 DEMETHYLATION OF MAMMALIAN SOMATIC DNA BY XENOPUS EGG AND OOCYTE EXTRACTS

2006 ◽  
Vol 18 (2) ◽  
pp. 169
Author(s):  
Y. Bian ◽  
R. Alberio ◽  
A. Johnson ◽  
K. Campbell
Keyword(s):  
Dna Replication ◽  
Nuclear Transfer ◽  
Somatic Cells ◽  
Donor Cell ◽  
Dna Demethylation ◽  
Xenopus Laevis Oocyte ◽  
Dependent Manner ◽  
Embryonic Cells ◽  
Egg Extracts ◽  
Xenopus Egg

In mammals, the successful development of live offspring by somatic cell nuclear transfer (SCNT) has demonstrated the ability of oocyte or egg cytoplasm to reprogram the differentiated status of somatic DNA. However, the efficiency of development is low, and this has been attributed to incomplete or inappropriate reprogramming of epigenetic status. One such epigenetic marker is methylation of genomic DNA at CpG islands. In SCNT, derived embryo abnormal DNA methylation patterns have been reported by a number of groups; in particular, it has been observed that the methylation pattern of embryonic cells resembles that of the donor cell (Santos et al. 2003 Curr. Biol. 13, 1116-1121). One strategy to improve reprogramming and, hence, development is to erase or reprogram the epigenetic status of the donor cell prior to nuclear transfer. We have previously reported that Xenopus egg and oocyte extracts show a differential effect on transcription. In oocyte extracts Pol I and II transcripts are maintained in the somatic cells; in egg extracts, these are abolished (Alberio et al. 2005 Exp. Cell. Res. 307, 131-141). To extend these studies, we have investigated the ability of oocyte and egg extracts to demethylate bovine somatic DNA. Preparation of Xenopus oocyte and egg extracts, culture, permeabilization of donor cells, and incubation conditions were all as previously described (Alberio et al. 2005 Exp. Cell. Res. 307, 131-141). Cells were incubated in extracts for 1 and 3 h at 21�C, centrifuged onto glass slides fixed in 4% Para formaldehyde for 15 min, followed by 4 M HCL for 1 h at 39�C, and blocked for 1 h. Cells were stained with mouse monoclonal anti-1MeC (1:50) overnight at 4�C followed by FITC-conjugated goat anti-mouse antibody (1:20) for 1 h at room temperature and mounted in Vectashied containing 10 �g of propidium iodide/mL. Nuclei were scored as positive or negative for 5MeC staining. In control cells, 90% of nuclei stained positively for 5MeC. In both oocyte and egg extracts the number of positive nuclei decreased with time showing demethylation of the somatic DNA 68 and 58% and 38 and 42% positive, respectively, after 1 and 3 h of incubation. Addition of apyrase (2%) to hydrolyze ATP inhibited demethylation in both extracts (90% nuclei positive). High rates of DNA replication were observed in somatic cells in egg extracts in contrast to no replication in oocyte extracts. Aphidicolin (1 �g/20 �L) was added to egg extracts to inhibit DNA replication, and under these conditions, DNA demethylation was abolished, suggesting a passive DNA demethylation mechanism as a result of DNA replication. In conclusion, Xenopus laevis oocyte and egg extracts can demethylate mammalian somatic DNA in an energy-dependent manner. In oocyte extracts, demethylation is independent of DNA replication, suggesting an active mechanism. In egg extracts, DNA replication is required, suggesting a passive mechanism. These studies further demonstrate the differences in reprogramming activities between oocyte and egg cytoplasm and suggest that interspecies extracts may provide a tool for nuclear reprogramming.

Timing of DNA replication of translocated Y chromosome sections in somatic cells of Drosophila melanogaster

Chromosoma ◽  
1969 ◽  
Vol 27 (4) ◽  
pp. 395-408 ◽  
Author(s):  
Carlotta Halfer ◽  
L. Tiepolo ◽  
C. Barigozzi ◽  
M. Fraccaro
Keyword(s):  
Drosophila Melanogaster ◽  
Dna Replication ◽  
Y Chromosome ◽  
Somatic Cells

scholarly journals Cdc25A Serine 123 Phosphorylation Couples Centrosome Duplication with DNA Replication and Regulates Tumorigenesis

2008 ◽  
Vol 28 (24) ◽  
pp. 7442-7450 ◽  
Author(s):  
Sathyavageeswaran Shreeram ◽  
Weng Kee Hee ◽  
Dmitry V. Bulavin
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Phosphorylation Site ◽  
Centrosome Duplication ◽  
Cycle Progression ◽  
Cdc25a Phosphatase

ABSTRACT The cell division cycle 25A (Cdc25A) phosphatase is a critical regulator of cell cycle progression under normal conditions and after stress. Stress-induced degradation of Cdc25A has been proposed as a major way of delaying cell cycle progression. In vitro studies pointed toward serine 123 as a key site in regulation of Cdc25A stability after exposure to ionizing radiation (IR). To address the role of this phosphorylation site in vivo, we generated a knock-in mouse in which alanine was substituted for serine 123. The Cdc25 S123A knock-in mice appeared normal, and, unexpectedly, cells derived from them exhibited unperturbed cell cycle and DNA damage responses. In turn, we found that Cdc25A was present in centrosomes and that Cdc25A levels were not reduced after IR in knock-in cells. This resulted in centrosome amplification due to lack of induction of Cdk2 inhibitory phosphorylation after IR specifically in centrosomes. Further, Cdc25A knock-in animals appeared sensitive to IR-induced carcinogenesis. Our findings indicate that Cdc25A S123 phosphorylation is crucial for coupling centrosome duplication to DNA replication cycles after DNA damage and therefore is likely to play a role in the regulation of tumorigenesis.

scholarly journals Dynamics of DNA Replication in Mammalian Somatic Cells

Cell ◽  
2003 ◽  
Vol 114 (3) ◽  
pp. 385-394 ◽  
Author(s):  
Mauro Anglana ◽  
Françoise Apiou ◽  
Aaron Bensimon ◽  
Michelle Debatisse
Keyword(s):  
Dna Replication ◽  
Somatic Cells
Sign in / Sign up

Export Citation Format

Share Document