Lederberg on the events leading up to his discovery of transduction

Well, I'll give you the chronology. I was only supposed to stay at New Haven for about three months, maybe 6 months over the summer, and then go back to medical school, but these experiments worked out so beautifully, that, well, I couldn't let them go, so I got a year's leave of absence, to spend 1 more year, and then I'd go back to medical school in December '47. Did a lot of work: all the basic papers on crossing came out during that year. And then it was a question of continuing my medical studies. Ed Tatum suggested another position, and that would be to go into research position at the University of Wisconsin. There were not many jobs like that around: there was no field of molecular biology, if that's imaginable to you, bacterial genetics and so on, but he knew that Wisconsin was creating an opening in that field, and entry opening, as an assistant professor, and he said look, the work you've already done would certainly qualify as a PhD dissertation. I was not there as a graduate student, but as a medical student on leave from Columbia, and we had the concurrence of all the faculty there at Yale that yes, I've been attending all the seminars, and there was the dissertation, and sure, they could enroll me retroactively as a graduate student. All I need to do is pay the year's tuition. And, that worked, and I was able to get my PhD, as an unintended outcome of my coming up to Yale, and that would qualify me to take this position, and after I was interviewed at Madison, they offered me the job. It was quite a dilemma whether to continue my studies or take the academic position, decided to do that. It was still too exciting a prospect to...I had a very definite sense, I was founding a new field. I came to Wisconsin in the fall of 1947, and so one of the first things you do is look for graduate students, and so I advertised for some, and Norton Zinder showed up in the fall of 1948. Norton had also known Ryan, he'd been an undergraduate at Columbia, had been frustrated about getting into medical school, and was going into research as a second alternative. He tells exactly the same story. He came into my lab as a graduate student, and discussing what he ought to do I said, well, salmonella is a very interesting bacteria, it's closely related to E.coli, but it's not the same, so why don't you see if you can find a way to cross salmonella. So, I put him through the ropes of showing him everything that he needed to learn about how to handle E.coli, and had to be a little more careful, salmonella was a pathogen, we had to watch out for that, and he and I would discuss the experiment every day; he actually did all the manipulation pretty much all by himself. And it ended up being his dissertation, and, instead of conjugation, it turned out to be still another mechanism, and that's transduction. The reason to look at salmonella was that there were phenomena about the inheritance of serological characters in salmonella, the serology of salmonella was worked out in much more detail than the E.coli because of its public health importance. So it's gotten a lot of attention, so there were literally hundreds if not thousands of different strains that have already been typed serologically, and I thought getting at the genetics... would be an important contribution; I think it was, but it was the original motives for going beyond E.coli. And that was just a big fat worm sitting under a rock. Once you picked up the rock, it was an absolutely stunning surprise to us that something as strange as viruses carrying genes from one cell to another can happen. Norton ended up being a professor here at Rockefeller, he came here 1951 or 52, and he's been on the faculty here ever since, so he preceded me here by many years.