Beadle, George Wells (1903–1989)

US biologist who was awarded the Nobel Prize for Physiology or Medicine in 1958 with Edward L Tatum and Joshua Lederberg for work in biochemical genetics, forming the ‘one-gene–one-enzyme’ hypothesis (a single gene codes for a single kind of enzyme).

Beadle was born in Wahoo, Nebraska. In 1931, he went to the California Institute of Technology, where he researched into the genetics of the fruit fly Drosophila melanogaster. From 1937 to 1946 he was professor at Stanford University, California, and it was during this period that he collaborated with Tatum.

Earlier, Beadle had shown that the eye colour of Drosophila is a result of a series of chemical reactions under genetic control. At Stanford, he used the red bread mould Neurospora crassa, which is a simpler organism than Drosophila. He subjected colonies of Neurospora to X-rays and studied the changes in the nutritional requirements of, and therefore enzymes formed by, the mutant Neurospora produced by the irradiation. By repeating the experiment with various mutant strains and culture mediums, Beadle and Tatum deduced that the formation of each individual enzyme is controlled by a single, specific gene. This concept found wide applications in biology and virtually created the science of biochemical genetics.