High-throughput screening of mouse knockout lines identifies true lean and obese phenotypes

Area of Science:

• Genetics
• Metabolism
• Mammalian Physiology

Background:

• Understanding the genetic basis of body fat regulation is crucial for metabolic disease research.
• High-throughput screening methods are needed to efficiently identify genes involved in complex physiological traits.
• Mouse models are essential for dissecting gene function and its impact on mammalian physiology.

Purpose of the Study:

• To develop and validate a high-throughput screening approach for identifying genes that regulate mammalian body fat.
• To assess the efficacy of this screen in detecting both lean and obese phenotypes.
• To discover novel genes influencing body fat stores.

Main Methods:

• Generated knockout (KO) mice for 5,000 potential human drug targets.
• Utilized dual-energy X-ray absorptiometry (DXA) to quantify body fat in KO and wild-type (WT) littermate mice.
• Validated screen performance using 13 benchmark KO lines with known lean or obese phenotypes.

Main Results:

• The screen demonstrated a normal distribution of normalized % body fat (nBF) values across 2322 KO lines.
• Benchmark KO lines with lean phenotypes showed significantly reduced nBF, while obese lines exhibited increased nBF.
• The screen successfully identified known lean/obese phenotypes and revealed novel associations, such as with kinase suppressor of ras 2 (KSR2).

Conclusions:

• The developed high-throughput DXA-based screen is a simple, cost-effective method for identifying genes regulating mammalian body fat.
• This approach can reliably detect established body fat phenotypes and discover novel genetic contributors.
• The findings provide a valuable resource for further research into metabolic regulation and drug target discovery.