Related Experiment Video
Updated: Jul 14, 2026

14:45
Transgenic Rodent Assay for Quantifying Male Germ Cell Mutant Frequency
Published on: August 6, 2014
Inferring somatic mutation rates using the stop-enhanced green fluorescent protein mouse
1Department of Medical Genetics, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
Genetics
|July 3, 2007
Summary
A novel method estimates somatic mutation rates in vivo using a stop-enhanced green fluorescent protein (EGFP) mouse model. This approach accurately detects mutagenicity, revealing a 200-2000 fold increase in mutation rates after exposure to N-ethyl-N-nitrosourea (ENU).
Area of Science:
- Toxicology
- Genetics
- Molecular Biology
Background:
- Estimating somatic mutation rates is crucial for understanding disease development and aging.
- Existing methods may lack sensitivity or precision for in vivo applications.
- Transgenic models offer controlled systems for studying mutation processes.
Purpose of the Study:
- To develop and validate a new method for quantifying in vivo somatic mutation rates.
- To assess the mutagenic potential of N-ethyl-N-nitrosourea (ENU) using this novel assay.
- To establish a sensitive test for detecting mutagenicity.
Main Methods:
- Utilized a stop-enhanced green fluorescent protein (EGFP) transgenic mouse model.
- Administered the mutagen N-ethyl-N-nitrosourea (ENU) or vehicle control to mice.
- Developed a stochastic model for mutation and gene expression, deriving maximum-likelihood estimators.
- Implemented a likelihood-ratio test (LRT) for mutagenicity detection, validated with parametric bootstrap simulations.
Main Results:
- The developed likelihood-ratio test (LRT) demonstrated high significance (alpha < 0.01) for detecting mutagenicity.
- A 95% confidence interval revealed a 200- to 2000-fold increase in mutation rate due to ENU exposure.
- The method effectively quantifies the relative effect of mutagens on somatic mutation rates in vivo.
Conclusions:
- The novel EGFP-based transgenic mouse assay provides a sensitive and quantitative method for assessing in vivo somatic mutation rates.
- This approach is effective in detecting and quantifying the mutagenic effects of chemicals like ENU.
- The developed stochastic model and LRT offer a robust framework for toxicological and genetic research.
Related Concept Videos
Mouse Models of Cancer Study
Mice have long served as models for studying human biology and pathology because of their phylogenetic and physiological similarity with humans. They are also easy to maintain and breed in the laboratory, and hence, many inbred strains are now available for research. Studies on mice have contributed immeasurably to our understanding of cancer biology.
The development of transgenic, knockout, and knock-in mice has led to an exponential increase in their use as model organisms in research,...
The development of transgenic, knockout, and knock-in mice has led to an exponential increase in their use as model organisms in research,...
In-vitro Mutagenesis
To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.
Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...

