Related Experiment Video

Updated: Aug 8, 2026

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins
10:24

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Published on: September 28, 2012

Formation and resolution of double-strand break intermediates in V(D)J rearrangement

D A Ramsden1, M Gellert

  • 1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0540, USA.

Genes & Development
|October 1, 1995
PubMed

Insights

This study reveals that broken signal ends and hairpin coding ends are key intermediates in V(D)J recombination. Signal end joining is slower than coding end resolution, potentially requiring cell cycle progression.

Area of Science:

  • Immunology
  • Molecular Biology
  • Genetics

Background:

  • V(D)J recombination is a crucial process for generating antibody diversity in lymphocytes.
  • Understanding the precise mechanisms and intermediates of V(D)J recombination is essential for comprehending immune system development and function.

Purpose of the Study:

  • To investigate the fate of double-strand breaks generated during immunoglobulin light-chain V(D)J rearrangement.
  • To characterize the kinetics and resolution pathways of signal and coding ends in this process.

Main Methods:

  • Utilized a pre-B cell line inducible for immunoglobulin light-chain rearrangement at high temperatures.
  • Analyzed the frequency and nature of broken signal and coding ends at the JK1 locus.
  • Monitored the accumulation of coding junctions over time.

Main Results:

  • 30%-40% of kappa (κ) loci exhibited broken JK1 signal ends after induction.
  • JK1-coding ends were significantly less frequent than signal ends.
  • Both hairpin and processed coding ends were observed, with coding junctions accumulating rapidly.
  • Signal ends remained largely unjoined until cells were returned to lower temperatures.

Conclusions:

  • Broken signal ends and hairpin coding ends are authentic intermediates in V(D)J recombination.
  • Coding ends are rapidly processed and resolved into coding junctions.
  • Signal end joining is a distinct, potentially slower process, possibly regulated by cell cycle progression or recombination machinery downregulation.

More Related Videos

Visualization of DNA Repair Proteins Interaction by Immunofluorescence07:55

Visualization of DNA Repair Proteins Interaction by Immunofluorescence

Published on: June 26, 2020

Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae07:55

Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae

Published on: September 11, 2022

Related Concept Videos

Nucleotide Excision Repair01:08

Nucleotide Excision Repair

Overview
Fixing Double-strand Breaks02:04

Fixing Double-strand Breaks

The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Fixing Double-strand Breaks02:04

Fixing Double-strand Breaks

The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...