“I like to look at questions from new angles”

A lab visit to Prof. Erez Raz / interview series by the Cells in Motion Cluster of Excellence
Prof. Erez Raz is a member of the Cells in Motion Cluster of Excellence and Director of the Institute of Cell Biology.
© WWU/Michael Kuhlmann

Prof. Raz, what scientific topic are you working on right now?

Our general aim is to understand how cells move in the body of a living organism and how they stay where they should stay. We work on specific cells – called germ cells – during embryonic development. These are the founder cells of every organism that reproduces sexually, as they later differentiate into sperm or egg cells. Germ cells are born at a certain place in the embryo and they then move to another location, in order to meet, interact with other cell types and form an organ – the gonad – at that position. We are trying to understand what controls this migration, and to this end we work with zebrafish. One advantage of zebrafish is that the embryo develops outside the mother’s body and that the embryos are transparent, which means that the cells are easily visible. As a result, we can observe the development inside the body “live”, so to speak. We use the findings as a model for basic processes shared by different organisms, including organisms that are more advanced than zebrafish. In addition, our research has relevance for clinical work: in the case of cancer or inflammation, for example, cell migration processes are misregulated. Understanding how cells move under normal circumstances would help to understand the basis for the abnormal pathological migration and to seek for solutions.

What characterizes you personally as a scientist?

I try to look at classical questions from new angles. I also like to change my mind about previous beliefs and be completely open to use new experimental approaches. The second thing that is close to my heart is training PhD students – supervising them over a number of years, watching their development and making a contribution to this process.

What’s your favourite research “toy” – and what can it do?

We primarily use different types of microscopes, which allow us to observe the processes we study at a high resolution within living organisms. I don’t have any favourite technique, as I don’t think there is just the one piece of technology. For example, if you have only an image or a video captured in a microscope, you can learn much more if you employ mathematics to improve the image, quantitate the findings and so on. It’s always the combination of various fields that characterizes good and innovative science.

Can you remember your happiest moment as a scientist?

I would say that there were two events that made me especially happy. One is when we found out that certain regions in an embryo play an important part in cell migration – when we discovered that there must be something that attracts the cells to certain places. The other moment that made me happy is when we could find the actual molecule that acted as the attractant.

And what was your biggest frustration?

Sometimes it is unavoidable that you go in a certain direction and discover at the end that it is leading you nowhere. For example, we sometimes find molecules that are expressed at an interesting pattern or within cells we are interested in. For that reason we believe that they play an important role in the process we study. However, in some cases we found that the molecules had no function we could notice. This is just one example of very frustrating moments – both for myself and also for the students. But it’s something you have to live with as a scientist.

Which scientific phenomenon still regularly fascinates you today?

Naturally enough, I’m fascinated by everything we do here – but I do not think there is anything in science that is not fascinating. After all, everything is connected to everything else. If I were to say I was only interested in the stripes on a zebrafish and would not use knowledge from other systems and branches of science, I wouldn’t make any progress. Of course, I know more about biology than about other disciplines in science, but I try to understand those, primarily in the course of collaborations with mathematicians, physicists and chemists.

What big scientific question would you like to have an answer to?

The big questions I ask myself are still: what allows cells to migrate from one position to another and what causes the cells to stay at one particular place in the end? I already have answers to small parts of these questions, but I’m still far from having a complete understanding. The further you progress, the more questions come up that you didn’t even know existed. Finding a complete answer to all aspects of a scientific question is extremely difficult if not practically impossible.

How much artistry, creativity and craftsmanship is there in your scientific work?

I think our creativity is in combining different approaches and techniques with one another, in order to find something new. Our craftsmanship, however, does not include constructing new equipment, for example. It’s like being an architect, who doesn’t physically build the walls himself but designs a new building based on available materials. And as to the question whether our science is art … I think it definitely is, in a certain way, but at the same time it’s much more restricted than “classic“ art. The reason is that I can’t give my fantasies completely freedom, because I’m directed and corrected by reality.