Second-generation high-throughput forward genetic screen in mice to isolate subtle behavioral mutants

Area of Science:

• Genetics
• Neuroscience
• Behavioral Science

Background:

• Forward genetic screens are crucial for identifying genes in biological processes.
• Traditional screens focus on extreme phenotypes, often missing genes with subtle effects.
• Behavioral screens in mice typically use high thresholds (3 SDs), leading to limited success and difficulties in gene mapping.

Purpose of the Study:

• To develop and validate a second-generation (G2) dominant N-ethyl-N-nitrosourea (ENU) screening method.
• To detect subtle behavioral mutants in mice with shifts of 1-2 SDs from wild-type.
• To establish a robust framework for forward genetic screens targeting subtle phenotypes.

Main Methods:

• Conducted a G2 dominant ENU screen specifically designed for subtle behavioral mutants.
• Utilized activity-based assays for open field activity and psychostimulant response.
• Applied a sensitive statistical and methodological framework to detect shifts of 1-2 SDs.

Main Results:

• Successfully detected mutant lines exhibiting subtle behavioral phenotypes (1-2 SD shifts).
• Screened 229 ENU mutant lines using the developed methodology.
• Identified 15 heritable mutant lines with subtle behavioral differences.

Conclusions:

• The G2 screening approach is effective for detecting subtle behavioral mutants in mice.
• This method improves the identification of genes underlying complex behaviors compared to traditional high-threshold screens.
• The robust framework supports future forward genetic screens for nuanced behavioral phenotypes.