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Friday 25 May 2012

What I do for a living... (part one)

I have decided that this blog has been under utilised, and have therefore set a weekly alarm on my phone to write a post. I'm going to try and keep them strictly non-my-music related and hopefully more science, tech and life related.

To get started, I thought I'd answer a question that I get asked a lot when I'm on tour: "what is it that you do for a living?".  In short, I am a post doctoral Research assistant at the University of Dundee. I have a degree in Physics, and am a Doctor of Engineering in Medical Devices (that's just a fancy PhD).

The long version, and I'm going to do this in two parts, is that I am investigating the motility forces that arise during early embryo development. We use the chicken as our model system, which is cool as you can remove it from the egg when it's only 10,000 cells or so and actually watch it develop up until the heart starts beating.

Before I started this job, I didn't really think about embryology. I mean, I knew the mechanics of mummy and daddy having special hugs because they are very much in love etc, but hadn't thought of it in smaller terms. When the egg (talking cells now, not calcium chicken containers) is fertilized it subsequently divides in to two identical cells, then four, then eight etc. After a while you have many thousands of identical cells in a small blob and something strange happens. The cells start to, for some unknown reason, differentiate in to different cell types and some even move in to specific locations. Very soon a body axis (giving a left and right hand side) is formed and the Embryo develops in to a living thing.
Dave's handy guide to embryogenesis

It is this transition from randomly placed cells to ordered body morphology that I am interested in. There are many questions that we want to answer, and many more to be asked. How do the cells generate forces to move? How do they know/learn where to move to? How and why does it go wrong?

An embryo is a very complex system, and therefore to research these questions we use a simpler model system called Dictyostelium discoideum, dicty for short. Dicty is what is known as a slime mould. Under normal conditions, they exist as single cell amoebas in the soil feeding off bacteria and going about their day.

However, under starvation something completely different happens. The cells secrete a chemical signal through their environment which tells them all to "Assemble!", and they come together to form a multicellular organism called a slug. This is made up of around 10,000 cells, and moves around like a real slug (hence its name). The slug moves towards light in the hunt for food, and when it can go no further, it transforms in to a plant like structure. Some of the cells die to produce the stalk, while others go in to a vegetative state in the fruiting body to wait for food. When conditions become favorable, the fruiting body bursts and the cells start their single celled lives again.

This life cycle and its transitions from single cells to multicellular organisms is just one of the reasons that dicty are interesting from a developmental biology point of view. Other reasons include the ease of genetically modifying the cells for learning about the internal workings, the biological machinery the cell uses to move is very well conserved from an evolution point of view. This means that the method in which dicty cells move is the same as many, including mammals, cells. Therefore, learn about dicty movement, learn and infer about many many more. Which brings us nicely back to why I use dicty. Oh, and it naturally lives in the soil so it's happy at room temperature making it easy for a non-biologist such as myself to use.

That's the biology side of what I do, I part two I'll tell you about the physics and engineering that I do with these squishy things.

I'm happy to answer any questions and actively encourage it.

SCIENCE! \0/