R-loops are common non-B nucleic acid structures formed by a three-stranded nucleic acid composed of an RNA-DNA hybrid and a displaced single-stranded DNA (ssDNA) loop. Because the aberrant R-loop formation leads to increased mutagenesis, hyper-recombination, rearrangements, and transcription-replication collisions, it is regarded as important in human diseases. Therefore, its prevalence and distribution in genomes are studied intensively. However, in silico tools for R-loop prediction are limited, and therefore, we have developed the R-loop tracker tool, which was implemented as a part of the DNA Analyser web server. This new tool is focused upon (1) prediction of R-loops in genomic DNA without length and sequence limitations; (2) integration of R-loop tracker results with other tools for nucleic acids analyses, including Genome Browser; (3) internal cross-evaluation of in silico results with experimental data, where available; (4) easy export and correlation analyses with other genome features and markers; and (5) enhanced visualization outputs. Our new R-loop tracker tool is freely accessible on the web pages of DNA Analyser tools, and its implementation on the web-based server allows effective analyses not only for DNA segments but also for full chromosomes and genomes.

Department of Informatics Mendel University in Brno Zemědělská 1 613 00 Brno Czech Republic

Faculty of Mechanical Engineering Brno University of Technology Technická 2896 2 616 69 Brno Czech Republic

Institute of Biophysics of the Czech Academy of Sciences Královopolská 135 612 65 Brno Czech Republic

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Special Issue "Bioinformatics of Unusual DNA and RNA Structures"