Christiane (Janni) Nüsslein-Volhard shared the 1995 Nobel Prize in Physiology or Medicine with Eric Wieschaus and Edward B. Lewis "for their discoveries concerning the genetic control of early embryonic development." While working at the European Molecular Biology Laboratory in Heidelberg, she and Eric conceived and carried out a saturation screen that identified the crucial genes involved in laying down the body plan of the Drosophila embryo, thereby ushering in the modern era of developmental biology.

Janni was interviewed by Kathy Weston during the 18th International Society for Developmental Biology meeting, held in Singapore in June 2017.

Kathy Weston: I know you've just finished writing a book about the point of beauty in nature—is that something you've always thought about in your work?

Janni Nüsslein-Volhard: Not really, actually. With zebrafish, I think I was always fascinated by their stripes, and the problem of how to make them and how to get those patterns, rather than that they were beautiful. We had mutants that had spots instead of stripes, and no one knew anything about them. But then of course you ask, "Why are the patterns there?" and then I got more and more into reading up on animal behavior and ethology.

Animal psychologists don't look at it from the point of beauty; they look at it from the point of signaling. Konrad Lorenz did publish an article posing the question of why coral reef fish are so beautiful, and he said at the time that people don't think this is a legitimate question for a biologist. It's almost blasphemic—people instinctively think beauty in nature is somehow made just for us to appreciate—there is no rationality behind it. And only Darwin thought seriously about it. He proposed that mate choice is partly driven by aesthetics, but his theory was so marginalized that it's almost been forgotten.

KW: Is one of the reasons you changed from bacteria to flies that they are just much more aesthetically pleasing?

JN-V: Absolutely! Fly embryos are adorable—they are so beautiful. It's a different type of beauty, more the human aesthetic pleasure, which is quite different from the animal's aesthetic pleasure.

I really wanted something to look at. I started as a child admiring plants and animals. I still do that—I still walk looking at the ground to see whether I find an insect or a plant or grass or whatever. Where I grew up there was a garden where I poked my fingers into the ground, and planted plants and looked at the birds and animals.

At university I wanted to do behavioral biology, but then somehow I ended up in biochemistry. I graduated in biochemistry and molecular genetics because at the time this was the most modern aspect, and I was ambitious—I wanted to go where the leaders were. The old-fashioned botanists and zoologists were such dull people—there was nothing interesting there.

After I graduated, I did molecular biology and it was interesting, but what I was doing did not have a future. There were people in the institute where I worked who did developmental biology with Hydra, and others doing bacterial genetics to find genes involved in DNA replication, and this convinced me of the power of genetics to identify morphogens. At the end of my thesis I spent months in the library to somehow find a system where you could combine developmental biology and genetics, and realized I should work on flies. And I looked around where the fly people were and ended up in Walter Gehring's laboratory.

KW: Do you think differently to other people?

JN-V: I'm sure I do! I have three sisters and a brother, and we have the very same upbringing, but I'm different. They think about people most of the time, and arts and music. Arts and music are also my great passion and interest, but in addition I like things—I like to poke into things, in contrast to being with people. I'm a shy person, I don't really need that too much. I have friends of course, and social relationships which are very strong. But I really like problems, and I like to solve problems—I'm an intellectual person.

KW: Eric [Wieschaus] has said that one unusual trait you both share is that you're really good at spotting really small differences.

JN-V: Eric is a painter, and he is extremely good at seeing things, and I'm also trained—my father is an architect, and my brother and sisters draw very well. I'm not as good as they are, but we were trained in looking at things and recognizing things, certainly. I love to do jigsaw puzzles—we did jigsaw puzzles when we were kids and then we started to make them ourselves, which I still do. We made them really difficult, and that certainly trains you to spot very tiny differences.

KW: What made you decide you wanted to move from flies to fish?

JN-V: We had found a large number of very fascinating mutants from the maternal screens in flies, and I feared we would have to clone them all. I'm not much of a biochemist—I studied it at diploma level, but I didn't like it very much—I'm an organismal biologist. So instead of having to do lots of sophisticated biochemistry, I thought that maybe we should do genetics, as that was more interesting for me. And so I decided we should look at vertebrate development.

We were happy we were able to start to understand some of the logic of development with the fly, but it was clear this didn't help us much with frogs or mice. And no-one knew whether the way they did things was the same or totally different. At the time, the methods people applied to understand mice or frogs were totally different to what we could do with flies, and mouse and frog genetics were impossible. The frog people even described development totally differently—we always used the term "genes," and they used the term "factors."

So in 1983, when we read George Streisinger's paper on making haploid fish embryos diploid, it was very exciting! In theory, it was a wonderful shortcut to making mutants. It doesn't work, but at the time we thought it might and that we could do genetics with a vertebrate. So we thought we could see how vertebrates could develop.

I bought my first fish from the pet shop and kept them in tanks on my windowsill. Streisinger had used zebrafish, but I was wondering whether they were the right choice, so I thought we should look around in case he was wrong. I tried other fishes and read up on them, but the zebrafish turns out to be the best. Medaka don't have stripes, and they have eggs in packages which are difficult to sort out, so they're not a good choice. At that time there was another species related to Danio which could be grown at lower temperature, and I thought that would be good, but it turned out that high temperature makes the fish grow faster, and this other species didn't have clutches of many eggs at once, but single eggs every day.

KW: Have you ever been bored with your work?

JN-V: After my thesis, I got bored, as it was tedious. I had done my thesis in pre-sequencing times, and if you can't sequence things, you don't get anywhere. I was working on the structure of a promoter, and we couldn't sequence it, so I would have had to develop methods to sequence DNA.

Later, when I was running a large lab and I wasn't directly involved in my own projects any more, I must say there were times when I found life a little bit dull. The other things I was doing were challenging, and the problem is that when you are distracted with other things, you cannot really focus enough, think enough. You have to spend time on just thinking about the problems, and if you don't have this, the science may go OK, but it will never be top. It can only be top if you really focus.

I notice now I spend much more time thinking about the experiments of the other people in the lab, and it's much more efficient—I'm back to waking up at night and thinking about a paper or a problem. And this is why we've had quite a lot of good papers very recently. But before that time, there were all these postdocs who did their own things, and I wasn't really involved enough.

Maybe people ruin their science by having too many people in the lab, because they're spread too thin and they have little direct influence on what the people are doing. If you don't do the experiments, you can only see what your lab tells you about, and if they don't see it, you miss it. Really good people are independent of you, and your lab will survive even if you don't get very involved in the projects, because the people are good enough. But if you have mediocre people, you have to push much harder, to control them more and advise them more. They make a lot of work. Every person in the lab causes you a lot of trouble, and if they're not good, it's very depressing, as there's no output.

KW: I know music plays a big part in your life—has that always been the case?

JN-V: There was a time when I was really frustrated with how things were going in the lab, so I took singing lessons and got very ambitious in trying to sing. I'm quite good now—I started singing lessons 10 years ago, and these days I can sing really difficult stuff. I sing lieder, combining poetry with music, and this is a wonderful thing—it's very important to me. And I played the flute as a child, and I love to play the flute now and do chamber music. Music is one of the best ways of communicating with other humans—it's just lovely.

Taking up new and challenging things as an adult is great fun. It uses totally different parts of your brain, and your energy and ambition, and you are a child all of a sudden again. You adore the teacher and you ask her for advice, and you're not in charge any more. I really like that!

KW: Has there been a downside to being a Nobel Laureate?

JN-V: I think it gave me some political problems, because people get so very envious. I had a lot of problems with colleagues, because they envied me my fame and they can be very very nasty. Sometimes you have experiences you wish you wouldn't have, and you wish to give the prize back and be a normal person again.

KW: How about the good things?

JN-V: You meet people you would otherwise not meet, and this is really great. I have the privilege to know many very high-class scientists and people. There is one very posh exclusive society in Germany, and they are all top-class artists and scientists—it's really lovely to be a member of this.

I also wrote a cookbook. It's 11 years old, and I still get a lot of compliments on it, but it took such a long time, so much work. I shouldn't have done it—this was my biggest sin. But it's an excellent cookbook—someone needs to translate it into English! I like cooking—it's similar to doing experiments, so when you can't do experiments any more it's a nice thing to do. And it's a good measure for how good you'll be in the lab. If you can do a five-course meal, you're going to be able to do experiments!