Rights: The University of Waikato Published 1 May 2006 Download

Cells contain thousands of genes but not every gene is used, and different combinations of genes are used at different times. Microarrays allow scientists to work out which genes are being used by different cells. Why is this so useful?


Warren McNabb (AgResearch)

Every cell we have in every part of our body has the same genes, but certain genes are expressed in certain cell types. So the genes in your eye that are being expressed are different to the genes in your liver that are being expressed.

Dr Bart Janssen (Plant & Food Research)

The microarray allows us to essentially ask which genes are being expressed in any one tissue at any one time. Unless you are looking at very simple traits, it is very unusual for one gene to have a huge effect. Almost always it’s a combination of multiple genes, and it’s often a sequence of events - a gene will come on, and then another will come on as that one goes off. Without looking at them all simultaneously, it’s very hard to see those kinds of interactions. The microarray allows us look at all these genes simultaneously.

Dr William Laing Plant & Food Research

It gives you a global picture. Rather than having to come from the approach of making a hypothesis that this gene is important, you isolate the gene and you study how it changes in expression ... you instead can look at a broad picture of what every gene in the organism is doing.

Dr Nicole Roy AgResearch

It's not new science. I mean, it's something that people have been doing for quite some time, but one gene at a time, two genes at a time. And the fact that we are now able, if you want to, to do a full screen to look at 30,000 genes, or 40,000 genes, in one analysis.

Warren McNabb AgResearch

So it enables us to get a much wider view of biology in that particular situation that we are doing an experiment in. It opens up a multitude of opportunities in terms of looking at whole pathways and how those pathways inter-relate.

Dr Bart Janssen Plant & Food Research

They are very important in understanding diseases like cancer - using microarrays to study gene expression to figure out which genes are expressed in particular cancer types. Otherwise a clinician cannot determine the difference between those cancer types. [If a clinician cannot determine the difference between the cancer types, treatment choices may be harder to make].