For my research into RNA metabolism I work on yeast, S. Cerivisiae; when I tell people this  I’m often asked why I’m not using human cells for my experiments which, my inquisitor believes, would be much more medically useful.

I think this is a common misconception, which stems from non-biologists not realising the connectedness of different life forms. Indeed, Sarah Palin enraged and amused the global scientific community in equal measure a few years back when she used the tale of Parisian geneticists studying fruitflies as an example of how scientists waste the public’s money.

But of course it’s important – as I have said many times – that the public understand why we scientists do the things we do with their money.  So with that in mind I’ve come up with a clever little analogy that you can use next time you’re round at your Nan’s house to explain why we use simple model organisms like yeast to gain an insight which will be useful to medical science.

Imagine you want to learn how a car works and you have access to two cars: a shiny new Mini made by BMW and one of those lovely old reliable classic Minis. You may have guessed that the new Mini represents the advanced human cell and the much loved old Mini the humble yeast.

Now to find out how the car works you are allowed to open the bonnet and tinker away, this is like a molecular biologist who deletes genes or pulls proteins out of the cell to see what they do.  So you open the new Mini up and see some shiny chrome and a lot of black plastic, it all looks a bit boring and you really can’t see how it might work or even how you might start taking it apart to figure out what it does. Now you look in the old Mini, it’s dirty but you can see wires, tubes and things that move when you turn the engine on.

So it’s clear to see which one will be easiest to start mucking around with to find out what all those bits do. The refined Mini made by BMW doesn’t like being played with, its engine is too complicated and inaccessible and all the moving bits are hidden away. The old mini however can be bashed around and is simply built, meaning you can tell what each part does relatively easily. Equally, playing with the old Mini is cheaper and you have more tools at your disposal thanks to the scrap yard! 

Now you know how the old Mini works: what a carburettor looks like and what the transmission is for. Through tinkering with an easily manipulable model you not only know how an old Mini works but a lot of what you’ve learnt can be applied to any car.

What you’ve learnt about the old Mini now informs how you approach finding out how the new Mini works, you come across the carburettor, which you know it is because it looks like the carburettor in the old Mini, you don’t need to pull it out – which as we have said is very difficult in a modern car – to see what it does because you’re already done that in the old car.

So you can see how studying a simpler, more manipulable version of what you’re really interested in can be advantageous to the researcher. Of course this is all possible because the Mini’s are both cars and yeast and human cells are both eukaryotes (one of the three classes of life forms on earth) and therefore share huge similarities which allow us to make generalisations of function and mechanisms.