title: Arena3D: visualizing time-driven phenotypic differences in biological systems.
abstract: BACKGROUND
  Elucidating the genotype-phenotype connection is one of the big challenges of modern molecular biology. To fully understand this connection, it is necessary to consider the underlying networks and the time factor. In this context of data deluge and heterogeneous information, visualization plays an essential role in interpreting complex and dynamic topologies. Thus, software that is able to bring the network, phenotypic and temporal information together is needed. Arena3D has been previously introduced as a tool that facilitates link discovery between processes. It uses a layered display to separate different levels of information while emphasizing the connections between them. We present novel developments of the tool for the visualization and analysis of dynamic genotype-phenotype landscapes.
  
  
  RESULTS
  Version 2.0 introduces novel features that allow handling time course data in a phenotypic context. Gene expression levels or other measures can be loaded and visualized at different time points and phenotypic comparison is facilitated through clustering and correlation display or highlighting of impacting changes through time. Similarity scoring allows the identification of global patterns in dynamic heterogeneous data. In this paper we demonstrate the utility of the tool on two distinct biological problems of different scales. First, we analyze a medium scale dataset that looks at perturbation effects of the pluripotency regulator Nanog in murine embryonic stem cells. Dynamic cluster analysis suggests alternative indirect links between Nanog and other proteins in the core stem cell network. Moreover, recurrent correlations from the epigenetic to the translational level are identified. Second, we investigate a large scale dataset consisting of genome-wide knockdown screens for human genes essential in the mitotic process. Here, a potential new role for the gene lsm14a in cytokinesis is suggested. We also show how phenotypic patterning allows for extensive comparison and identification of high impact knockdown targets.
  
  
  CONCLUSIONS
  We present a new visualization approach for perturbation screens with multiple phenotypic outcomes. The novel functionality implemented in Arena3D enables effective understanding and comparison of temporal patterns within morphological layers, to help with the system-wide analysis of dynamic processes. Arena3D is available free of charge for academics as a downloadable standalone application from: http://arena3d.org/.
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, Heidelberg 69117, Germany. secrier@embl.de
authors.forename: Maria
authors.initials: M
authors.lastname: Secrier
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Pavlopoulos
authors.forename: Jan
authors.initials: J
authors.lastname: Aerts
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schneider
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D053595:Embryonic Stem Cells / Q000378:metabolism; D044127:Epigenesis, Genetic; D055785:Gene Knockdown Techniques; D005838:Genotype; D006801:Humans; D051379:Mice; D010641:Phenotype; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism; D012984:Software; D014158:Transcription, Genetic
chemical_list: D011506:Proteins