title: Identifying functional gene sets from hierarchically clustered expression data: map of abiotic stress regulated genes in Arabidopsis thaliana.
abstract: We present MultiGO, a web-enabled tool for the identification of biologically relevant gene sets from hierarchically clustered gene expression trees (http://ekhidna.biocenter.helsinki.fi/poxo/multigo). High-throughput gene expression measuring techniques, such as microarrays, are nowadays often used to monitor the expression of thousands of genes. Since these experiments can produce overwhelming amounts of data, computational methods that assist the data analysis and interpretation are essential. MultiGO is a tool that automatically extracts the biological information for multiple clusters and determines their biological relevance, and hence facilitates the interpretation of the data. Since the entire expression tree is analysed, MultiGO is guaranteed to report all clusters that share a common enriched biological function, as defined by Gene Ontology annotations. The tool also identifies a plausible cluster set, which represents the key biological functions affected by the experiment. The performance is demonstrated by analysing drought-, cold- and abscisic acid-related expression data sets from Arabidopsis thaliana. The analysis not only identified known biological functions, but also brought into focus the less established connections to defense-related gene clusters. Thus, in comparison to analyses of manually selected gene lists, the systematic analysis of every cluster can reveal unexpected biological phenomena and produce much more comprehensive biological insights to the experiment of interest.
authors.affiliation: Institute of Biotechnology, PO Box 56 (Viikinkaari 5), FIN-00014, Helsinki, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Kankainen
authors.forename: Günter
authors.initials: G
authors.lastname: Brader
authors.forename: Petri
authors.initials: P
authors.lastname: Törönen
authors.forename: E Tapio
authors.initials: ET
authors.lastname: Palva
authors.forename: Liisa
authors.initials: L
authors.lastname: Holm
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016000:Cluster Analysis; D003080:Cold Temperature; D019295:Computational Biology / Q000379:methods; D003681:Dehydration; D020869:Gene Expression Profiling / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D020407:Internet; D010937:Plant Growth Regulators / Q000494:pharmacology; D012984:Software
chemical_list: D010937:Plant Growth Regulators; D000040:Abscisic Acid