Neurospora: the organism behind the molecular revolution.

U NDER the title “Fifty Years Ago: The Neurospora Revolution,” HOROWITZ (1 99 1) has celebrated an anniversary of the epochal 1941 paper of BEADLE and TATUM, which reported the first mutants with biochemically defined nutritional requirements. HOROWITZ’S account and others (HOROWITZ 1973, 1985, 1990; LEDERBERC 1990) have focused on the people who were involved, the genesis of their ideas, and the role of the 1941 results in transforming biology. The present essay will be concerned mainly with the research organism that was so important to the success of the initial experiments. Neurospora possesses a combination of features that made it an ideal choice not only for accomplishing the original objectives set by BEADLE and TATUM but also for a continuing succession of contributions, including many in areas that transgress the bounds of biochemical genetics and molecular biology. 1 shall begin by outlining the story of Neurospora prior to BEADLE and TATUM and then go on to sketch its subsequent history. The previous accounts have stressed biochemical genetics and molecular biology. I shall consider other aspects as well, focusing first on genetics, continuing with a summary of research accomplishments of all sorts, and concluding with a consideration of the potential usefulness of Neurospora for population studies. The vegetative phase of Neurospora was described and used for experiments by French microbiologists nearly 100 years before BEADLE and TATUM (PAYEN 1843; MONTAGNE 1843). In the warm, humid summer of 1842, bread from bakeries in Paris was spoiled by massive growth of an orange mold. A commission was set up by the minister of war to investigate the cause of the infestation and to make recommendations. The commission’s report (PAYEN 1843) includes a colored plate which shows colonies, mycelia, conidiophores and conidia of the “champignons rouges du pain.” An experiment in photobiology is described. Colonies