Genetic Control of Biochemical Reactions in Neurospora

The work of George Beadle and Edward Tatum, primarily conducted with the mold Neurospora crassa, established the one gene–one enzyme hypothesis. Their experiments involved exposing the mold to X-rays to induce mutations and then observing how these mutants grew in a minimal nutrient medium. They discovered that some mutated strains required specific amino acids to grow, indicating a disruption in their metabolic pathways. This led them to conclude that each gene controls the production or function of a single enzyme, which in turn regulates a specific biochemical reaction. This groundbreaking research, which united genetics and biochemistry, earned Beadle and Tatum the Nobel Prize in Physiology or Medicine in 1958.123