How do knockout mice help researchers learn about the roles of genes?

A knockout mouse is a laboratory mouse (Mus musculus) engineered to have a specific gene inactivated. By observing the resulting modifications in phenotype—the mouse's observable traits—researchers can deduce the biological function of that gene.1

Because mice and humans share many genes, these models are essential for understanding the genetic basis of human disease. Researchers use techniques like homologous recombination to target specific genes or gene trapping to disrupt genes randomly. By comparing the knockout mouse to a normal subject, scientists can identify the gene's role in processes such as:

• Fetal and organ development1
• The establishment of body plans1
• The progression of disorders like cancer, diabetes, and Parkinson disease1

While some gene inactivations are lethal or produce no observable change, these models remain a powerful platform for testing novel drug therapies and advancing medical knowledge.1