GOMA: Web utility for direct finding of enriched Gene Ontology terms from gene expression profile

Microarrays have become popular devices used to elucidate changes of cell status. Following microarray experiments, technicians would like to verify their observations and changes of cell status occurring because of stimuli during experiments. Currently, we validate analyses of several or hundreds of samples using clustering and visualization. However, comparison is not an easy task because knowledge of data analysis is required and hundreds of clusters might be produced. This study presents GOMA, a web-based expression enrichment checking server using Gene Ontology (GO). By putting sets of gene names and expressions into the server, which GO categoriespsila genes are enriched can be verified immediately, and changes of cell status can be detected. The server presents a graphical GO structure association of their terms to ease the checking scheme. We evaluate that our web server enables us to recognize functions associated with changes of gene expression and to elucidate effects of different stimuli. The experimental results shows that our web server detects aldo-keto reductase activity under sorbitol supplemental condition from yeast expression data automatically, and our server visualizes the functional changes between sorbitol condition and stationary phase. GOMA is available online at http://goma.sel.is.ocha.ac.jp/ .