Analysis of gene expression by microarrays: cell biologist's gold mine or minefield?

The development of DNA microarrays to study simultaneously the level of mRNA expressed from thousands of genes offers great promise to cell biologists. Microarrays can be used to gain detailed information about transcriptional changes involved in a specific pathway, potentially leading to the identification of novel components of the signalling system. They can also be used to obtain a fingerprint of the transcriptional status of the cell under a given condition, which may be useful for characterising the pathways used in response to novel stimuli. The use of microarrays will generate huge amounts of expression data, contributing to the transformation of biology from a data-poor to a data-rich science. Whether this leads to real advances in the understanding of cell biological problems will depend on the development of methodologies, both in experimental biology and in bioinformatics, that allow meaningful knowledge to be extracted from all this information.