A random mutation capture assay to detect genomic point mutations in mouse tissue

Area of Science:

• Genetics
• Molecular Biology
• Toxicology

Background:

• Transgenic mouse models are commonly used to study mutagenesis.
• Existing methods often rely on phenotypic selection, which can limit sensitivity and applicability.
• A need exists for direct mutation detection assays in endogenous genes across various mouse strains.

Purpose of the Study:

• To describe a simplified and highly sensitive protocol for the random mutation capture (RMC) assay.
• To enable direct measurement of nuclear point mutation frequency in mouse tissues.
• To provide a versatile alternative to transgenic mouse models for in vivo mutagenesis studies.

Main Methods:

• Detailed protocol for the random mutation capture (RMC) assay in mouse tissue.
• Direct detection of mutations in endogenous genes, not relying on reporter genes.
• Analysis of mutation frequencies in liver tissue from mice with mutations in DNA polymerases δ and ε.

Main Results:

• The RMC assay is highly reproducible and sensitive for measuring mutation frequency in mouse introns.
• Mice with mutations in DNA polymerases δ and ε showed significantly higher mutation frequencies than wild-type controls.
• The RMC assay demonstrated higher sensitivity compared to the Big Blue assay for the analyzed genotypes.

Conclusions:

• The RMC assay is a versatile and sensitive tool for measuring in vivo mutagenesis in any mouse strain.
• It allows for direct detection of mutations in endogenous genes, overcoming limitations of transgenic models.
• Simultaneous analysis of mutation frequency at multiple genetic loci is feasible with the RMC assay.