Student Mark Sterken - MSc Biology

“Biology is the study of life and that’s what makes it interesting to me. I want to know how an organism works and functions at the (sub)cellular level”, says Mark Sterken, a fifth year biology student.

There is nothing better than, after a hard day's work, to realise that your idea works.


Currently he is working on his thesis. He does research in ‘genetical genomics in Caenorhabditis elegans’. This is a nematode (a type of small worm) and an ideal organism to do research on. It has a generation span of less than four days (that is the time that elapses until they reach maturity), you can see them grow on a petri dish and they don’t fly away. In genetical genomics one makes use of so-called ‘micro-arrays’. These are microscope slides on which you can find ‘targets’ (more than 45,000). These targets can bind a specific type of messenger RNA. It measures how much mRNA per gene is present and it can give you an idea of the whole gene expression in the organism.

“I measure this gene expression in all the different crossings of two subspecies of C. elegans (called N2 and CB). Because we know where these genomes of these two subspecies have recombined, we can correlate the difference in gene expression with the recombination in the genome (this approach is called genetical genomics). Suppose that gene X can sometimes have a high and sometimes a low expression, then it is possible that if the gene comes from the CB genome, it will have a relatively high expression and when it comes from the N2 genome , it will have a low expression. We view this for all those 45,000 genes.”

“It is unfeasible to view each crossing (I use 60 in my research) with the naked eye for each of the 45,000 targets to see whether there is a difference in gene expression. That is why I use computers to do the analysis for me. The combination of computers and biology is a powerful one, because you can do research that was unthinkable even ten years ago. Furthermore, in this research you can find yourself on the brink of the current knowledge and it is up to you to figure out how you tackle a problem. Of course, various errors occur in research, but there is something in return: there is nothing better than, after a hard day's work, to realise that your idea works and you are getting good results.”