François Jacob


Interview, December 2001

Interview with Professor François Jacob by Joanna Rose, science writer, 8 December 2001.

Professor Jacob talks about the experience of going from “completely unknown to too much known” when the Pasteur Group was awarded the Nobel Prize. He talks about how he got into sciences in 1950 (1:56) and about his colleagues André Lwoff and Jacques Monod (5:48). He also shares his thoughts about the development of biology since 1950 (11:12).

Interview transcript

Welcome to the Nobel interview, Professor François Jacob. You have written earlier that the Nobel Prize has changed your life, not only in a positive way, you also realised that it put some kind of burden on your back.

François Jacob: The group we had in the Pasteur Institute with Lwoff, Monod and several people was rather unknown of the French public. We had a lot of foreign students; American students, British, German and so on and so forth, but very few French students. This group was ignored of the French authorities and French university and suddenly at one certain Thursday at noon the news arrived that you were awarded the prize and it worked like a wave. I mean all the newspaper, all the TV which were around in Paris just came there, and it was just like a wave you receive in full face. And then from being completely unknown we became too much known very rapidly, and it’s a bit difficult for a time to face this situation but you finally can do it.

So, what happened?

François Jacob: So what happened that we go on working, and it has also positive thing in the sense that you can more easily get support for your work, that you can more easily get good students and so forth. So you have a good side and a bad side on this of course.

Yes. You were not only unknown, you were also kind of hidden in the attic of the Pasteur Institute.

… I knew nothing in science and I decided that I’d give me five years …

François Jacob: That’s right, the attic was … Lwoff made some very important discovery before the war and he was made head of the department in the Pasteur Institute and the department which was created for him, which was bacterial physiology and he was given this attic on one of the buildings of the Pasteur Institute and when I arrived after the war I knew nothing in science. I had been wanting to do surgery and I was very heavily wounded and I had a bad arm and bad leg so I couldn’t do surgery and I tried to be an actor, I tried to do journalism, I did a lot of things and finally I tried to go into science but, as I said, I knew nothing in science and I decided that I’d give me five years, either I find something in five years or I do something else.

And when was it?

François Jacob: This was in 1950. But the point is I learned that there were two good labs in Paris and one which was nicer than the other. The nicer one was the one which was headed by Lwoff and in which Monod was working, at the Pasteur Institute, and it was already at the Pasteur Institute, and I went and saw Lwoff and asked him whether I could work with him and he said No, I have no room, and for a year I came every month asking him whether I could work with him and finally he was so fed up with me that he said Yes and this was in the middle of 1950, yes.

So you ended up on this attic?

François Jacob: So ended up in this attic and the attic was very interesting because it was a long corridor, at one pole there was Lwoff and his group, at the other was Monod and his group, and in the middle people were always meeting, talking, discussing, trying to put down the experiment of the other and criticising each other. It was extremely lively and extremely active and in this attic a large number of foreign people, as I said, was coming every year. So it was fantastically intellectual living place.

Yes, and you had also many contacts with the American scientists?

François Jacob: Yes, there were many American scientists coming in, either professor for sabbatical year or post doc students.

And you used also to go to Cold Spring Harbor?

François Jacob: Yes, I went to Cold Spring Harbor for the first time in 1953 and it was very interesting. I mean the students and the whole atmosphere was very different from what was existing in France.

In what way?

François Jacob: In France when the professor had said something the student said Ok, well good, very good and in the States it was very funny. They were criticising strongly the professors and arguing with them. It was a very different climate but very interesting and when we went there in the States we tried to import in Europe, in France anyway, the American way of teaching and all this, yes.

Did you succeed with that?

François Jacob: Partly, not completely but partly.

How do you remember Jacques Monod and André Lwoff as persons? 

François Jacob: They were very different from each other, although Lwoff was some kind of an artist, actually he liked also to paint and he painted a lot and he had the intuition of the important problems. When he started with certain scientific problem and he went deeply in, but when you arrive at a certain success and a certain discovery then he stopped and he changed and went to another problem and he changed; I don’t know four, five times in his life and every time very successfully. He started with the vitamins and he explained what vitamins was and he came to viruses and bacteriophages showing that the genes of a virus can become part of a bacteria gene chromosome. Then he turned to other viruses, so changed he a lot.

Monod was completely the opposite. If he stared in one problem, which were his doctoral thesis then he went on all his life going deeper and deeper on this particular problem. So they were completely different but extremely good friends.

And you were the third one I would say in this trio, the youngest one and what kind of scientist are you?

François Jacob: Oh, I wonder. I was in the middle. I worked with Lwoff finally after this, but I said that I’d be going every month to him. Finally, he told me one day, You know we have found the induction of the prophage. I said, Oh. I was very admirative, but I didn’t understand a word of what he was saying and when I came out of that I just went to library and I couldn’t find out what a prophage or induction of a prophage was. Finally, I understood later on, but I told him: I am dying to do that with you, and so he accepted me and I began to work there. So I worked with him and did my thesis with him but after that I worked with Elie Wollman, who was just a little bit older than I was and we worked on the genetics of bacteria and we were able to analyse the whole genetic system, the way bacteria can copulate.  It was a system which had been found by Josh Lederberg and we analysed in detail.

… that was my role – to be in between and put the two things together …

But once we had this system in hand it was clear that it was a fantastic tool to analyse any function of the bacterial cell. So it turned out that it was important for the kind of problem that Monod was investigating, which was how the genes activity respond to environment, that our system of bacteria copulation was a very good tool to analyse that so I turned and worked with Monod at that time. And it turned out a very funny thing that Monod was working at one side on enzymes and disease and Lwoff was working on viruses and it turned out that the system were extremely similar, extremely alike and then you could make a general model of the way gene activity is regulated by using either system, that was my role – to be in between and put the two things together.

Yes, in one corridor. You did also write about the way science works and you use these words that you can divide science in two parts; one is day science and one is night science. Can you elaborate a bit on that?

François Jacob: That’s right. When you look at books or you look at papers people write you find that science is a nice treat, that you can go from one point to another in a very classical way and very profound way but I don’t think it’s the way science is. In fact, by night, when you are in your bed and you don’t sleep you wonder what you are doing, you hesitate to do this, is what I do reasonable? And it has nothing to do with the habitual description of the glory that you have, “la jardin française”, where you can walk, it’s very different from that and that’s what I call day science, which is the finished science, that’s what you look in the books and the night science which is the actual way when you fight with everything and wonder and being sure to be wrong, in fact.

But you were right. 

François Jacob: Sometimes you’re right.

This time in science where you entered it in 1950s, this was really a time of revolution in biology. How do you view the development of biology since then?

François Jacob: Well, there are two points which are important I think. One was that going on with the success beginning of molecular biology was to work with bacteria and viruses because it was very simple. You could analyse very simply and you could find a lot of mutants, you could make a lot of combinants, you could go to the genetic material itself, find out how it works; that was very nice and extremely successful. But when you wanted to apply these techniques to higher organisms, actually we were interested in ourselves finally, you couldn’t do that, and it became possible through genetic engineering and genetic engineering came out in the beginning of the 1970s.

It happened that you could isolate DNA, sequence DNA, pick up a gene, look at the presence of a gene, put him in a different organism or bacteria. You could do a lot of things, and then this gave access to higher organisms, that was essentially at the 1970s, and it became possible at the beginning of 1980s to tackle another absolutely fundamental problem of biology, which is embryonic development. That is how does it happen that you take a sperm cell, an egg cell, put them together, you have an egg and this gives two cells, four cells, eight cells and this gives you or me, that’s really the most fantastic problem you can imagine, that you have this four cells, eight cells; and then you have a small part which happened which has become distinct, a group of cells which is going to give the brain with which you learn to talk, to write, to come to Stockholm or to go through the street.

This was just impossible to believe 20 years ago …

This was really one of the big mysteries and it was impossible to handle seriously before this genetic engineering was possible and this we have learnt a lot and we have learnt incredible things, things which were completely incredible 20 years ago. For instance, that the same genes which make the plan of an insect, of a “drosophile”, the fly, the same gene make the plan for a human being or mouse or well … This was just impossible to believe 20 years ago.

Yes, here we are.

François Jacob: And here we are, yes. Probably there will be more extraordinary thing in the coming years.

Can you see something that will come? Can you speculate on that?

François Jacob: No. I mean I am not Madam Soleil. In France we have a very famous predictor who’s called Madam Soleil, Mrs Sun, and she sees anything, you can say “n’importe quoi” but if you make prediction you’re sure to be wrong, that’s the only thing you can say. Except one thing that probably the brain will be the main… because the brain is the thing which know the least and probably this will be the main object of the coming year.

This is very interesting. Thank you for taking your time and sharing your thoughts with us.

François Jacob: You’re welcome.

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