[Q] Are we going to talk about Jacob for a moment?

Yeah, well I think the… François was of course extremely pleased with this, because this wasn't in the sort of thing that they were doing. And yet to have brought this from another direction and, you know, really reinforce the ideas they had, that in fact… you know, what regulation was involved – because that was what they were interested in – was in fact turning on gene expression. Because that's what made this inevitable. I mean, a little bit later than this, François and I actually did an experiment to prove this, which we published in the Comptes Rendus and it's gone unnoticed. But we… actually the first formal proof that induction involves new messenger synthesis is in a paper we did together in about 1962, I think it was published, which involved proving that galactose messenger is produced when you induce the galactose operon, that was the only way we could do it at the time. But that is of course how it fitted in, and it fitted in with the genetics of the operator constitutive and the operator zero. Of course it's the operator zero which in fact is wrong. Because all the operator zeros were polar mutants of the protein. The concept was right, but they weren't the right things. Roughly speaking, what they could say… what they said is that there was part of the gene that controlled the expression of the gene, and that you could break this switch in two positions. Either on or off. And if it was broken off you couldn't get anything from it, and if it was broken on you got it all the time. Now that in… that in theory is correct, but when you have repression, it's hard to see what... what breaking it in the off position is, because you can think, if you don't sit on it, it'll just go on. But what does it mean to say that you don't get anything? So that was one of the problems there, and of course later we showed that many of these operator zeros were polar nonsense mutants. So formally that was, you know, doing the right thing for the wrong reason.

[Q] François was a geneticist, he…

François was a geneticist, he was not a… a biochemist in that sense. He had done… he… he had come from lambda where all of these concepts were developed about repression. And… and of course the tradition in Paris was lambda. Tradition all over the world – the rest of the world – was bacteriophage T4 – these were the virulent bacteriophages – and that was because people in… in America were totally influenced by Delbrück, who didn't believe in lysogeny. And so not… nobody worked on lambda in the West until quite recently. On the other hand, Elie Wollman's parents, who had done all of… of really classic work on lysogeny in the '20s, and who were at the Pasteur Institute, were, I mean, a great tradition at the Pasteur Institute, they died in concentration camps during the war, and Elie had come to Paris to, so to speak, continue the Wollman tradition, and it was Elie who initiated all that work, and who, in a sense, François joined. And so these were all the papers on Wollman-Jacob, and with their whole analysis of induction which they did with André Lwoff – the UV induction, and the whole investigation of lysogeny – that all centred in Paris, and was those concepts of the phage repressor and realising that the beta-galactosidase system was similar – isomorphous in fact – that led to these two streams going together. But certainly the concepts were of phage, and the concepts could not have been developed out of the phages we were using. And there was no tradition of doing that. Whereas they had worked on lysogeny. I was… I knew about lysogeny; I wanted to work on lysogeny with Hinshelwood, but he wouldn't let me. But I think that's quite interesting, about that.