Mouse Mutagenesis Using N-Ethyl-N-Nitrosourea (ENU).

Area of Science:

• Genetics
• Molecular Biology
• Toxicology

Background:

• Chemical mutagenesis is crucial for generating genetic variation in model organisms.
• N-ethyl-N-nitrosourea (ENU) is a potent mutagen used for creating point mutations in mice.
• Phenotype-driven screens are essential for discovering gene function.

Purpose of the Study:

• To describe a protocol for chemical mutagenesis in male mice using ENU.
• To highlight the utility of ENU-induced mutations for genetic screens.
• To establish a resource for dissecting gene function and discovering novel mutations.

Main Methods:

• Fractionated dose administration of ENU to male mice.
• Targeting spermatogonial stem cells for mutation induction.
• Utilizing genetic screens (dominant, recessive, modifying) to identify mutations of interest.

Main Results:

• ENU achieves a high mutation rate (up to 1.5 × 10^-3) in male mouse spermatogonial stem cells.
• ENU induces point mutations, offering a resource independent of position effects.
• Mutations generated display a spectrum of effects, including loss-of-function and gain-of-function.
• Enables unbiased discovery of gene functions.

Conclusions:

• ENU-based chemical mutagenesis is an efficient method for generating mouse mutations.
• This approach provides a powerful tool for phenotype-driven genetic screens.
• The resulting mutant resource facilitates detailed functional genomics studies.