heat maps - how to read/understand them (May/24/2009 )

Hi,

Can anyone suggest a website, book or paper which explains hows to read/understand a heat map. I have been asked to read on this topic. Each cells in a heat map represents the expresison of a gene and teh expression intensity is colour coded e.g. red for high expresison etc. But my main cincern is that when peope publish a heatmap, all teh reader see's a bock of red,yello and green colours. It doens

Usually heatmaps are presented to show patterns of genes being regulated.

This means that showing each and every name would be very cumbersome, instead you show genes from a given pathway or with similar Gene Ontology (GO) terms.

So, as an example, if I would like to show that a given drug causes DNA damage in my cells I could look for genes in the p53 pathway and look at their expression pattern.