Diana Downs, professor of microbiology, has made transformative contributions to her field by exploiting genetic analysis to help solve important biochemical mysteries of bacterial life. A key theme of her research is that pulling one thread of metabolism reveals interconnected threads in unexpected ways. By using a biochemical genetic approach, she has advanced understanding of thiamine synthesis, specifically uncovering connections between this pathway and others in the cell. Her genetic research has also provided insight into the complexities of chemistry inside all cells and the evolution of new pathways. Her work has yielded ideas and information critical to understanding how pathways are controlled and have evolved. Downs has elucidated previously unknown metabolic networks, revealed subtle metabolic connections in bacteria and mapped new mechanisms of metabolic regulation. These mechanisms are conserved in biology, making her basic biomedical research relevant to applied fields like metabolic engineering, synthetic biology and infectious disease.