大象传媒

Professor Iain Johnston at the Department of Mathematics (UiB) has spent years studying mitochondria 鈥� the tiny energy-producing compartments inside cells from animals to plants and fungi. He explains that if you look down the microscope at mitochondria in plant cells, you see that there are hundreds of them, and they are moving around 鈥� almost like in a city. They are meeting up, breaking apart, exchanging information.

鈥淐learly there is something important going on here. Can we understand these principles that drive these complicated and very important motions? This must be happening for some reason, and we are going to figure out what that reason is,鈥� he says.

New Approaches听

Johnston鈥檚 interdisciplinary research has already been underway for several years, with funding from the European Research Council, and it was recently announced that it has gotten another four years of funding from The Research Council of Norway.

"The project follows the philosophy of our research group 鈥� which is about combining mathematical, computational, and lab approaches to try to understand questions in biology. We鈥檙e particularly interested in questions that are hard to test in the lab 鈥� especially the kinds of 鈥榳hy鈥� questions biologists are often told not to ask,鈥� Johnston says.

The focus of the project is on mitochondria 鈥� the tiny compartments inside the cells of humans, plants, fungi and all sorts of complex life. One of the main roles of mitochondria is to provide energy in a form that our cells need.听

Social Interaction

Johnston鈥檚 team will particularly be looking at mitochondria in plants and marine animals 鈥� something that has not been as well studied as mitochondria in humans and other mammals.听

鈥淎nd rather than focusing on one particular species we are going to be as broad as possible. Looking at things that look like plants across the world,鈥� he says. 听

Mitochondria have their own DNA, and it encodes some important bits of cellular machinery.听

鈥淥ur theory is that the physical dynamics of these things 鈥� all this crazy city-like motion that we see 鈥� helps maintain that DNA, and helps it contribute to the cell. It鈥檚 like a trade network -- individual mitochondria share safe copies of this DNA by exchanging with their neighbors in the cell. These mitochondria need social interaction to thrive,鈥� Johnston says.

Simulation Model

Johnston and his team will be using a combination of microscopy and mathematical modelling. Following this 鈥渃ity鈥� metaphor, he says that his coming research will be inspired by ideas from the field of urban planning.

He explains that in biology it is common to ask questions by doing something to a system that compromises its behaviour, and then try to dissect why the change happened. But it is difficult to do that with the tiny mitochondria.听

鈥淲e don鈥檛 have many means of mucking up this behaviour. So, what we can do is to build a simulation model. We can write a little bit of code that creates this process virtually. And then we have complete control over the entire system,鈥� Johnston explains.

A New Kind of Lab

This gives the researchers a new kind of laboratory 鈥� one powered by mathematics and simulation. On his computer, Johnson presents a series of generated images and animations depicting tiny dots navigating the interior of plant cells.

鈥淲e try to make sure that out model is grounded in reality. We are always engaging in what biology actually does, so that we can try to be a bit more realistic about what could and what couldn鈥檛 happen in the model world,鈥� Johnston explains.

Johnston and his colleagues argue that the social metaphor for mitochondria is particularly accurate in plants.

鈥淚f you look at mitochondria in other species, they are often fused up into big network. But in plants you do see that it is genuinely individuals who go around and interact with each other in the cell,鈥� Johnston says.

Could Have a Practical Outcome

This project is about basic or fundamental science 鈥� which means that it aims to understand how the world works 鈥� not to solve a specific practical problem right away, but to uncover the underlying principles and mechanisms behind a natural phenomenon. It gets to ask the big questions, like the why questions in biology.听

But Johnston also thinks his research could lead to practical benefits in the future. By helping us better understand how biology works at a fundamental level, his work could lay the groundwork for new ideas, technologies, or treatments down the line.听

鈥淥ne future application could be in crop breeding. Hybrid crops are normally higher yielding and provide more food for a given bit of land. One way of making hybrids is by exploiting mitochondrial mutations. Better understanding plant mitochondria could suggest new approaches for this exploitation,鈥� he says.

He explains that there is a scientific understanding of this process already, but much of it is on a case by case basis.听

鈥淲e learn about particular cases in which mitochondrial mutations give rise to male sterility. One hope of the applied nature of this project is to reveal general principles 鈥� the foundation for this overall behaviour. I鈥檓 actually super keen to apply it, not just in established crops, but emerging crops like seaweed, like macro algae, which is also a focus of what we are looking at in the proposal,鈥� Johnston says.

A Physicist that Loves Biology听

Iain Johnston is originally a physicist, turned mathematician.

鈥淚n physics we are very used to the idea that there are fundamental laws in the universe 鈥� like thermodynamics, relativity and so on. But I鈥檓 a physicist that loves biology. And in biology there really aren鈥檛 so many fundamental laws, but there are ideas that apply across the biological world: evolution, energy and noise and randomness. It is that intersection of ideas that put me where I am,鈥� he says.听

Working on this project in a place like Bergen adds new aspects to the experience, according to Johnston.听

鈥淚t is a super inspiring place to work! We are going to be working on the theory of what is going on in the tips of those trees over there and out in the ocean over there. You go for a run over the mountains or you go for a swim down at the beach, and you see all of the species and the beauty of the plant world that you are working on. To be embedded in this wonderful showcase of nature that you are trying to explain is inspiring,鈥� he says.

If you are interested reading more about this project, and seeing some of the images,
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