1. RNA-Biology and Bioinformatics, Institute of Biomedical Genetics, University of Stuttgart , Allmandring 31 , 70569 Stuttgart, Germany
2. Bioinformatics Group, Department of Computer Science, University of Freiburg , Georges-Köhler-Allee 106 , 79110 Freiburg, Germany
3. Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig , Härtelstr. 16-18 , 04107 Leipzig, Germany
4. Genetics and Experimental Bioinformatics, Institute of Biology III, University of Freiburg , Schänzlestr. 1 , 79104 Freiburg, Germany