scholarly journals Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique

10.3791/3255 ◽  
2011 ◽  
Author(s):  
Rebekka A.V. Schwab ◽  
Wojciech Niedzwiedz
Keyword(s):  
Dna Replication ◽  
Model System ◽  
Vertebrate Model

scholarly journals The State of the Art of the Zebrafish Model for Toxicology and Toxicologic Pathology Research—Advantages and Current Limitations

2003 ◽  
Vol 31 (1_suppl) ◽  
pp. 62-87 ◽  
Author(s):  
Jan M. Spitsbergen ◽  
Michael L. Kent
Keyword(s):  
Molecular Genetic ◽  
Model System ◽  
Developmental Genetics ◽  
Zebrafish Model ◽  
Vertebrate Model ◽  
Pathologic Lesions ◽  
Minimal Data ◽  
Advanced Knowledge ◽  
The Rich ◽  
Mutant Lines

The zebrafish (Danio rerio ) is now the pre-eminent vertebrate model system for clarification of the roles of specific genes and signaling pathways in development. The zebrafish genome will be completely sequenced within the next 1—2 years. Together with the substantial historical database regarding basic developmental biology, toxicology, and gene transfer, the rich foundation of molecular genetic and genomic data makes zebrafish a powerful model system for clarifying mechanisms in toxicity. In contrast to the highly advanced knowledge base on molecular developmental genetics in zebrafish, our database regarding infectious and noninfectious diseases and pathologic lesions in zebrafish lags far behind the information available on most other domestic mammalian and avian species, particularly rodents. Currently, minimal data are available regarding spontaneous neoplasm rates or spontaneous aging lesions in any of the commonly used wild-type or mutant lines of zebrafish. Therefore, to fully utilize the potential of zebrafish as an animal model for understanding human development, disease, and toxicology we must greatly advance our knowledge on zebrafish diseases and pathology.

scholarly journals Profiling DNA Replication Timing Using Zebrafish as an In Vivo Model System

10.3791/57146 ◽  
2018 ◽  
Author(s):  
Joseph C. Siefert ◽  
Emily A. Clowdus ◽  
Duane Goins ◽  
Amnon Koren ◽  
Christopher L. Sansam
Keyword(s):  
Dna Replication ◽  
Replication Timing ◽  
Model System ◽  
Dna Replication Timing

scholarly journals TRAIP drives replisome disassembly and mitotic DNA repair synthesis at sites of incomplete DNA replication

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Remi Sonneville ◽  
Rahul Bhowmick ◽  
Saskia Hoffmann ◽  
Niels Mailand ◽  
Ian D Hickson ◽  
...  
Keyword(s):  
Dna Repair ◽  
Dna Replication ◽  
Ubiquitin Ligase ◽  
Early Embryo ◽  
Model System ◽  
Replication Forks ◽  
Nematode Caenorhabditis Elegans ◽  
Repair Synthesis ◽  
Dna Repair Synthesis ◽  
Early Mitosis

The faithful segregation of eukaryotic chromosomes in mitosis requires that the genome be duplicated completely prior to anaphase. However, cells with large genomes sometimes fail to complete replication during interphase and instead enter mitosis with regions of incompletely replicated DNA. These regions are processed in early mitosis via a process known as mitotic DNA repair synthesis (MiDAS), but little is known about how cells switch from conventional DNA replication to MiDAS. Using the early embryo of the nematode Caenorhabditis elegans as a model system, we show that the TRAIP ubiquitin ligase drives replisome disassembly in response to incomplete DNA replication, thereby providing access to replication forks for other factors. Moreover, TRAIP is essential for MiDAS in human cells, and is important in both systems to prevent mitotic segregation errors. Our data indicate that TRAIP is a master regulator of the processing of incomplete DNA replication during mitosis in metazoa.

Distinct roles of cdk2 and cdc2 in RP-A phosphorylation during the cell cycle

1993 ◽  
Vol 106 (3) ◽  
pp. 983-994 ◽  
Author(s):  
F. Fang ◽  
J.W. Newport
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Binding ◽  
Dna Binding Protein ◽  
Model System ◽  
S Phase ◽  
Chromosomal Dna ◽  
Cdc2 Kinase ◽  
Single Stranded Dna

RP-A is a single-stranded DNA-binding protein, which has been shown to be required for DNA replication using an SV40 model system. The protein has also been shown to be phosphorylated at the G1-S phase transition. Using Xenopus cell-free extracts we have investigated the role of RP-A in nuclear replication and characterized the kinases and conditions that lead to phosphorylation of RP-A during the cell cycle. By immunodepleting RP-A from Xenopus extracts we have shown that RP-A is essential for replication of chromosomal DNA. Our results show that, during S phase, only that RP-A which is associated with nuclei is phosphorylated. Furthermore our results indicate that during S phase RP-A is only phosphorylated when associated with single-stranded DNA. By immunodepleting cdk2 kinase we show that cdk2 kinase is required for the observed phosphorylation of RP-A in nuclei during S phase. However, using purified cdk2 kinase and RP-A we are unable to detect a direct phosphorylation of RP-A by cdk2 kinase. This observation suggests that phosphorylation of DNA-bound RP-A at S phase is carried out by a kinase distinct from cdk2. Consistent with this we find that when single-stranded DNA is added to S phase extracts depleted of cdk2 kinase, RP-A is phosphorylated. Together these results suggest that cdk2 kinase participates in the activation of DNA replication at a stage prior to the binding of RP-A to the initiation complex. In addition to RP-A phosphorylation in S phase, we have also found that at the onset of mitosis RP-A is quantitatively phosphorylated and that phosphorylation is directly mediated by cdc2 kinase. However, at this time during the cell cycle, cdc2-dependent phosphorylation of RP-A is independent of DNA binding. These observations further demonstrate the distinctions between cdk2 and cdc2 kinases.

scholarly journals In Vivo Imaging of Disease-Related Mitochondrial Dynamics in a Vertebrate Model System

2012 ◽  
Vol 32 (46) ◽  
pp. 16203-16212 ◽  
Author(s):  
G. Plucinska ◽  
D. Paquet ◽  
A. Hruscha ◽  
L. Godinho ◽  
C. Haass ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Mitochondrial Dynamics ◽  
Model System ◽  
Vertebrate Model
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