Prof Andreas Bausch, Technical University of Munich
Now letís hear more from one of the other talks Buzz mentioned, from Professor Andreas Bausch from the Technical University of Munich in Germany. Heís trying to understand how patterns and structures form in nature, and showed some beautiful and striking movies of simple molecules coming together to create all kinds of shapes that move around. I asked him to explain how he and his team generated these stunning images from simple biological molecules.
Andreas - So, my model system is the cytoskeleton which is a polymer network inside of cells. We try to purify the components and then we see how they self-organise in beautiful spherical spirals or going to form waves, and so on. We try to really control what kind of patterns emerge.
Kat - Can you tell me a little bit more about the cytoskeleton? What is it inside cells?
Andreas - So, this is a polymer network which makes the cells stiff and gives us all the shapes.
Kat - Itís almost like a scaffold inside the cell?
Andreas - Yeah, right. Itís a scaffold and itís responsible for all kind of processes of cell division, cell migration, transport inside of cells. So, itís a rather universal polymer network and there's a lot of physics behind it. I think the beauty here is that a lot of physical concepts and measurement techniques are necessary to explore this kind of very complicated polymer network. Itís much more complicated than all the polymer networks we know from a daily basis. So rubber is trivial compared to the complexity we have in cells. That's actually what is life about. Itís already have high complexity and high integration density of functionality on this very small scale to have all these functions on this very small length scales.
Kat - So, what do you do in your lab to study these very, very complex systems?
Andreas - The idea is that we go from a bottom-up approach where we purify components and add step by step complexity and control the complexity which is kind of completely different than traditional biology would do it, that they come from a cell organism and go down. We try to really be on the physics approach where we really add the complexity step by step.
Kat - So, you're starting with the building blocks of a scaffold, putting them all in a test tube and seeing what happens.
Andreas - Yeah. Basically, that's what we do. We mix and watch.
Kat - We saw some beautiful, beautiful things. Tell me about some of the patterns you see.
Andreas - So, we see spirals, for example, where they move around or the galaxy forms where you get density waves in the spiral. You'll see waves like ocean waves walking over the cover slide. The amazing thing is that we span a lot of the length scale. So, the single filament is 7 nanometre and patterns are up to centimetres. So, this is unheard of length scales you're expanding here, where you get really kind of higher order structures out of very small interactions at very small length scales. Then we see also some shapes where we have spherical objects which change their shape into citrons or scallops or whatever. So, there's all kind of a zoo of different patterns and forms which we have here. That's the fascinating shapes are the fascinating thing here.
Kat - Sometimes it can be hard to think how do we go from the information amount of genes, it makes proteins and then it organises into these amazing structures. But looking at your images, you kind of start to see how life might work.
Andreas - Yeah, I guess weíre on the upper end from the gene expression. We donít think about gene expression and the regulation of the gene expression. We have already the proteins. If you just let 2 or 3 proteins interact, it starts to emerge, the shapes emerge and patterns and dynamics emerge, and that's the fascinating thing here. The goal is evidently that we really want to mimic some real process like cell division or cell migration in the test tube with purified components. That's the ultimate goal we have here.
Kat - What's the weirdest thing you've seen in the results that you've got?
Andreas - The weirdest thing, I guess they all were weird the first time we saw them because they all were unexpected. The most fascinating I think these days is now, these vesicles which change shape in a very deterministic way which we never expected, in a very kind of mathematically pure, which nobody would expect it because it should unordered. So, we see kind of pure physics and pure mathematics coming out from a very complicated four-component system and that's kind of fascinating.
Kat - Some people say, biology, itís really just applied physics. Do you think we can break down the amazing process of life to physical rules one day?
Andreas - I guess that's exactly what's happening right now and I think we need much more physics coming into this complexity of biology to really break it down to principles and identify principles behind it. I think these experiments showed examples where you see that there is some hope that we can come up with some minimalistic systems where you see that already 3 or 4 components do a function. In nature, in real biology, you may have 10 or 20 proteins doing that, but four with defined function are enough to do it. And then you would have understood quite a bit already.
Kat - That was Professor Andreas Bausch from the Technical University of Munich.