Related Experiment Video
Updated: May 23, 2026
10:59
Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
Mismatch repair-dependent mutagenesis in nondividing cells
Gina P Rodriguez1, Nina V Romanova, Gaobin Bao
1Department of Biology, Department of Radiation Oncology, and Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA.
Summary
DNA mismatch repair (MMR) can create new phenotypes in yeast nondividing cells. This replication strand-independent MMR activity may explain adaptive mutation and contribute to tumor formation.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Mismatch repair (MMR) is a crucial DNA repair pathway.
- MMR typically operates in a replication strand-specific manner to correct DNA replication errors.
Purpose of the Study:
- To investigate the role of MMR in creating new phenotypes in nondividing cells.
- To explore MMR activity independent of DNA replication.
Main Methods:
- Experiments were conducted using yeast models.
- Analysis of DNA sequences and repair mechanisms in both dividing and nondividing cells.
Main Results:
- Mismatched DNA bases escaping MMR during replication can be repaired by MMR in nondividing cells.
- This repair occurs in a replication strand-independent manner, leading to either wild-type or mutant sequences.
- This activity was observed to drive adaptive mutation in one instance.
Conclusions:
- Replication strand-independent MMR activity in nondividing cells can generate genetic variation.
- This mechanism may contribute to tumor development in nondividing cells.
- It could also play a role in mutagenesis during processes like somatic hypermutation of immunoglobulin genes.
Related Concept Videos
01:20Mismatch 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...
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...
01:36Mismatch Repair
Overview
01:36Mismatch Repair
Overview
02:04Fixing 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...
02:04Fixing 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...
01:38Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...