Profiles in genetics: George Wells Beadle and the origins of the gene-enzyme concept.
Beadle's success in establishing biochemical genetics on a firm foundation was due to a combination of several circumstances. These include the following: 1. Apt timing of his work, which Garrod's work clearly lacked, was important. Geneticists were receptive to his ideas and conclusions. As Beadle (1967, 1974) himself acknowledged, much ground was prepared earlier by Garrod and Haldane, who discussed gene action in terms of biochemical reactions, although it was largely ignored. The physiology of gene action was discussed and speculated on to a great extent in the preceding years by Bridges, Goldschmidt, Muller, and Wright. 2. Beadle's selection of Neurospora was most appropriate. It was a haploid organism (with no complications of dominance and recessivity) that could be grown and manipulated easily for isolating mutants to study their segregation and recombination within a short time. Its cytogenetics and the method of growing on chemically defined media were already worked out. It was devoid of the long generation time and more complex sex cycle (among other problems) that complicated the biochemical study of higher plants (e.g., Primula), which Haldane and Scott-Moncrieff had attempted earlier. 3. Beadle's striking ability to shift from one organism to another--from corn to Drosophila to Neurospora--must be acknowledged. He saw the limitations of existing methods and had the courage and skill to move on to more successful methods: from conventional breeding to tissue transplants to microbiological techniques. 4. Beadle's own curiosity about the biochemical nature of gene action and his good fortune in having had such outstanding teachers as Emerson, as well as his ability to collaborate with Ephrussi and Tatum, contributed largely to his success.
Dronamraju
K R
KR
Genetics Center, Houston, Texas 77215.
D004798:Enzymes / Q000235:genetics*; D005823:Genetics / Q000266:history*; D049673:History, 20th Century; D014481:United States
D004798:Enzymes