Related Experiment Video

Updated: Aug 8, 2026

Visualization of UV-induced Replication Intermediates in E. coli using Two-dimensional Agarose-gel Analysis
10:36

Visualization of UV-induced Replication Intermediates in E. coli using Two-dimensional Agarose-gel Analysis

Published on: December 22, 2010

Arrested DNA replication in Xenopus and release by Escherichia coli mutagenesis proteins

N Oda1, J D Levin, A Y Spoonde

  • 1Office of Scientific Director, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, Maryland 20892, USA.

Science (New York, N.Y.)
|June 14, 1996
PubMed

Insights

Xenopus oocytes can repair DNA damage but struggle to replicate it. Adding specific bacterial proteins enabled replication of damaged DNA, offering insights into cellular DNA lesion management.

Area of Science:

  • Molecular Biology
  • DNA Repair Mechanisms
  • Cellular Biology

Background:

  • Xenopus oocytes possess DNA repair capabilities for double-stranded DNA.
  • Replication of single-stranded to double-stranded DNA is a key cellular process.
  • Ultraviolet (UV) radiation induces DNA photoproducts, such as cyclobutane pyrimidine dimers.

Purpose of the Study:

  • To investigate the replication of UV-damaged single-stranded DNA in Xenopus oocytes.
  • To determine factors influencing replication arrest on damaged DNA.
  • To explore methods for alleviating replication blocks in the presence of DNA lesions.

Main Methods:

  • Utilized M13 single-stranded DNA (ss DNA) containing cyclobutane pyrimidine dimers.
  • Microinjected messenger RNAs encoding prokaryotic mutagenesis proteins (UmuD'C, MucA'B) into oocytes.
  • Observed DNA replication and maintenance in Xenopus oocytes under various conditions.

Main Results:

  • M13 ss DNA with UV photoproducts was maintained but not replicated in normal Xenopus oocytes.
  • Progesterone maturation enabled replication of the damaged M13 ss DNA.
  • Replication arrest was a cis-acting phenomenon.
  • Injection of UmuD'C or MucA'B mRNA relieved the replication arrest.

Conclusions:

  • Xenopus oocytes exhibit distinct responses to DNA damage during replication.
  • Prokaryotic mutagenesis proteins can overcome replication blocks caused by DNA lesions in a eukaryotic system.
  • These findings provide potential mechanisms for cellular stabilization of repair and replication on damaged DNA.

More Related Videos

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts10:55

Study of the DNA Damage Checkpoint using Xenopus Egg Extracts

Published on: November 5, 2012

Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System11:19

Inducing a Site Specific Replication Blockage in E. coli Using a Fluorescent Repressor Operator System

Published on: August 21, 2016

Related Concept Videos

Replication in Prokaryotes02:35

Replication in Prokaryotes

Overview
Replication in Eukaryotes02:31

Replication in Eukaryotes

Overview
Mismatch Repair01:36

Mismatch Repair

Overview
Replication in Prokaryotes01:32

Replication in Prokaryotes

DNA replication has three main steps: initiation, elongation, and termination. Replication in prokaryotes begins when initiator proteins bind to the single origin of replication (ori) on the cell's circular chromosome. Replication then proceeds around the entire circle of the chromosome in each direction from the two replication forks, resulting in two DNA molecules.
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
Replication in Eukaryotes01:29

Replication in Eukaryotes

In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Mismatch Repair01:20

Mismatch Repair

Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...