ZINDER, NORTON DAVID

born Nov. 7, 1928, New York, N.Y., U.S. American biologist who discovered the occurrence of genetic transductionthe carrying of hereditary material from one strain of microorganisms to another by a filterable agent such as a bacteriophage, or bacterial virusin species of the Salmonella bacteria. After attending Columbia University, Zinder studied under Joshua Lederberg at the University of Wisconsin (Ph.D., 1952) and then joined the staff at the Rockefeller Institute for Medical Research (now Rockefeller University) in New York City, where he became a professor in 1964. Zinder hoped to go beyond Lederberg's 1946 discovery of mating in the bacterium Escherichia coli. By allowing species of Salmonella to conjugate (to exchange genetic material in a kind of reproduction) in a special nutritional medium, Zinder hoped to obtain a large number of mutant bacteria to use in his experiments. Instead of conjugating, however, the bacteria exhibited another form of genetic exchange, genetic transduction. Using bacterial transduction, later experimenters were able to show that bacterial genes affecting selected physiological processes were clustered together in what are now known as operons. Zinder's experiments also led to the discovery of the only known phage containing ribonucleic acid (RNA) as its genetic material.