scholarly journals Transcription-associated processes cause DNA double-strand breaks and translocations in neural stem/progenitor cells

2016 ◽  
Vol 113 (8) ◽  
pp. 2258-2263 ◽  
Author(s):  
Bjoern Schwer ◽  
Pei-Chi Wei ◽  
Amelia N. Chang ◽  
Jennifer Kao ◽  
Zhou Du ◽  
...  
Keyword(s):  
B Cells ◽  
Progenitor Cells ◽  
Great Majority ◽  
Cell Types ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Transcription Profiles ◽  
Neural Stem Progenitor Cells

High-throughput, genome-wide translocation sequencing (HTGTS) studies of activated B cells have revealed that DNA double-strand breaks (DSBs) capable of translocating to defined bait DSBs are enriched around the transcription start sites (TSSs) of active genes. We used the HTGTS approach to investigate whether a similar phenomenon occurs in primary neural stem/progenitor cells (NSPCs). We report that breakpoint junctions indeed are enriched around TSSs that were determined to be active by global run-on sequencing analyses of NSPCs. Comparative analyses of transcription profiles in NSPCs and B cells revealed that the great majority of TSS-proximal junctions occurred in genes commonly expressed in both cell types, possibly because this common set has higher transcription levels on average than genes transcribed in only one or the other cell type. In the latter context, among all actively transcribed genes containing translocation junctions in NSPCs, those with junctions located within 2 kb of the TSS show a significantly higher transcription rate on average than genes with junctions in the gene body located at distances greater than 2 kb from the TSS. Finally, analysis of repair junction signatures of TSS-associated translocations in wild-type versus classical nonhomologous end-joining (C-NHEJ)–deficient NSPCs reveals that both C-NHEJ and alternative end-joining pathways can generate translocations by joining TSS-proximal DSBs to DSBs on other chromosomes. Our studies show that the generation of transcription-associated DSBs is conserved across divergent cell types.

scholarly journals Genome integrity and neurogenesis of postnatal hippocampal neural stem/progenitor cells require a unique regulator Filia

2020 ◽  
Vol 6 (44) ◽  
pp. eaba0682 ◽  
Author(s):  
Jingzheng Li ◽  
Yafang Shang ◽  
Lin Wang ◽  
Bo Zhao ◽  
Chunli Sun ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Neurodevelopmental Disorders ◽  
Double Strand Breaks ◽  
Genome Integrity ◽  
Replication Forks ◽  
Proof Of Concept ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Strand Breaks ◽  
Neural Stem Progenitor Cells

Endogenous DNA double-strand breaks (DSBs) formation and repair in neural stem/progenitor cells (NSPCs) play fundamental roles in neurogenesis and neurodevelopmental disorders. NSPCs exhibit heterogeneity in terms of lineage fates and neurogenesis activity. Whether NSPCs also have heterogeneous regulations on DSB formation and repair to accommodate region-specific neurogenesis has not been explored. Here, we identified a regional regulator Filia, which is predominantly expressed in mouse hippocampal NSPCs after birth and regulates DNA DSB formation and repair. On one hand, Filia protects stalling replication forks and prevents the replication stress-associated DNA DSB formation. On the other hand, Filia facilitates the homologous recombination–mediated DNA DSB repair. Consequently, Filia−/− mice had impaired hippocampal NSPC proliferation and neurogenesis and were deficient in learning, memory, and mood regulations. Thus, our study provided the first proof of concept demonstrating the region-specific regulations of DSB formation and repair in subtypes of NSPCs.

scholarly journals Oncogenic transformation in the absence of Xrcc4 targets peripheral B cells that have undergone editing and switching

2008 ◽  
Vol 205 (13) ◽  
pp. 3079-3090 ◽  
Author(s):  
Jing H. Wang ◽  
Frederick W. Alt ◽  
Monica Gostissa ◽  
Abhishek Datta ◽  
Michael Murphy ◽  
...  
Keyword(s):  
B Cells ◽  
Chromosomal Translocation ◽  
Double Strand Breaks ◽  
Nonhomologous End Joining ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Class Switch ◽  
Ig Heavy Chain ◽  
Peripheral B Cells

Nonhomologous end-joining (NHEJ) repairs DNA double-strand breaks (DSBs) during V(D)J recombination in developing lymphocytes and during immunoglobulin (Ig) heavy chain (IgH) class switch recombination (CSR) in peripheral B lymphocytes. We now show that CD21-cre–mediated deletion of the Xrcc4 NHEJ gene in p53-deficient peripheral B cells leads to recurrent surface Ig-negative B lymphomas (“CXP lymphomas”). Remarkably, CXP lymphomas arise from peripheral B cells that had attempted both receptor editing (secondary V[D]J recombination of Igκ and Igλ light chain genes) and IgH CSR subsequent to Xrcc4 deletion. Correspondingly, CXP tumors frequently harbored a CSR-based reciprocal chromosomal translocation that fused IgH to c-myc, as well as large chromosomal deletions or translocations involving Igκ or Igλ, with the latter fusing Igλ to oncogenes or to IgH. Our findings reveal peripheral B cells that have undergone both editing and CSR and show them to be common progenitors of CXP tumors. Our studies also reveal developmental stage-specific mechanisms of c-myc activation via IgH locus translocations. Thus, Xrcc4/p53-deficient pro–B lymphomas routinely activate c-myc by gene amplification, whereas Xrcc4/p53-deficient peripheral B cell lymphomas routinely ectopically activate a single c-myc copy.

scholarly journals Parp3 promotes long-range end-joining in murine cells

2018 ◽  
Author(s):  
Jacob V. Layer ◽  
J. Patrick Cleary ◽  
Alexander J. Brown ◽  
Kristen E. Stevenson ◽  
Sara N. Morrow ◽  
...  
Keyword(s):  
Chromosomal Rearrangements ◽  
Embryonic Stem ◽  
Cell Types ◽  
Double Strand Breaks ◽  
Nonhomologous End Joining ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Class Switch

AbstractChromosomal rearrangements, including translocations, are early and essential events in the formation of many tumors. Previous studies that defined the genetic requirements for rearrangement formation have identified differences between murine and human cells, most notably in the role of classical‐ and alternative-nonhomologous end joining factors (NHEJ). We reported that poly(ADP)ribose polymerase 3 (PARP3) promotes chromosomal rearrangements induced by endonucleases in multiple human cell types. In contrast to c-NHEJ factors, we show here that Parp3 also promotes rearrangements in murine cells, including translocations in murine embryonic stem cells (mESCs), class switch recombination in primary B cells and inversions in tail fibroblasts that generate Eml4-Alk fusions. In mESCs, Parp3-deficient cells had shorter deletion lengths at translocation junctions. This was corroborated using next-generation sequencing of Eml4-Alk junctions in tail fibroblasts and is consistent with a role for Parp3 in promoting the processing of DNA double-strand breaks. We confirmed a previous report that Parp1 also promotes rearrangement formation. In contrast with Parp3, rearrangement junctions in the absence of Parp1 had longer deletion lengths, suggesting Parp1 may suppress DSB processing. Together, these data indicate that Parp3 and Parp1 promote rearrangements with distinct phenotypes.

scholarly journals The Maize Transposable Element Ac Induces Recombination Between the Donor Site and an Homologous Ectopic Sequence

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 1143-1151
Author(s):  
Gil Shalev ◽  
Avraham A Levy
Keyword(s):  
Transposable Element ◽  
Donor Site ◽  
Double Strand Breaks ◽  
Plant Genome ◽  
Blue Staining ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Reading Frame ◽  
Strand Breaks ◽  
Ectopic Recombination

The prominent repair mechanism of DNA double-strand breaks formed upon excision of the maize Ac transposable element is via nonhomologous end joining. In this work we have studied the role of homologous recombination as an additional repair pathway. To this end, we developed an assay whereby β-Glucuronidase (GUS) activity is restored upon recombination between two homologous ectopic (nonallelic) sequences in transgenic tobacco plants. One of the recombination partners carried a deletion at the 5′ end of GUS and an Ac or a Ds element inserted at the deletion site. The other partner carried an intact 5′ end of the GUS open reading frame and had a deletion at the 3′ end of the gene. Based on GUS reactivation data, we found that the excision of Ac induced recombination between ectopic sequences by at least two orders of magnitude. Recombination events, visualized by blue staining, were detected in seedlings, in pollen and in protoplasts. DNA fragments corresponding to recombination events were recovered exclusively in crosses with Ac-carrying plants, providing physical evidence for Ac-induced ectopic recombination. The occurrence of ectopic recombination following double-strand breaks is a potentially important factor in plant genome evolution.

Role for Artemis nuclease in the repair of radiation-induced DNA double strand breaks by alternative end joining

DNA Repair ◽  
2015 ◽  
Vol 31 ◽  
pp. 29-40 ◽  
Author(s):  
Mario Moscariello ◽  
Radi Wieloch ◽  
Aya Kurosawa ◽  
Fanghua Li ◽  
Noritaka Adachi ◽  
...  
Keyword(s):  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks ◽  
Alternative End Joining ◽  
Radiation Induced

Involvement of Ku80 in microhomology-mediated end joining for DNA double-strand breaks in vivo

DNA Repair ◽  
2007 ◽  
Vol 6 (5) ◽  
pp. 639-648 ◽  
Author(s):  
Yukitaka Katsura ◽  
Shigeru Sasaki ◽  
Masanori Sato ◽  
Kiyoshi Yamaoka ◽  
Kazumi Suzukawa ◽  
...  
Keyword(s):  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Strand Breaks
Sign in / Sign up

Export Citation Format

Share Document