WordCluster: detecting clusters of DNA words and genomic elements Hackenberg , Michael Carpena, Pedro Bernaola-Galván, Pedro Barturen, Guillermo Alganza, Ángel M. Oliver, José Luis Genomic elements DNA words Bioinformatics WordCluster Background Many k-mers (or DNA words) and genomic elements are known to be spatially clustered in the genome. Well established examples are the genes, TFBSs, CpG dinucleotides, microRNA genes and ultra-conserved non-coding regions. Currently, no algorithm exists to find these clusters in a statistically comprehensible way. The detection of clustering often relies on densities and sliding-window approaches or arbitrarily chosen distance thresholds. Results We introduce here an algorithm to detect clusters of DNA words (k-mers), or any other genomic element, based on the distance between consecutive copies and an assigned statistical significance. We implemented the method into a web server connected to a MySQL backend, which also determines the co-localization with gene annotations. We demonstrate the usefulness of this approach by detecting the clusters of CAG/CTG (cytosine contexts that can be methylated in undifferentiated cells), showing that the degree of methylation vary drastically between inside and outside of the clusters. As another example, we used WordCluster to search for statistically significant clusters of olfactory receptor (OR) genes in the human genome. Conclusions WordCluster seems to predict biological meaningful clusters of DNA words (k-mers) and genomic entities. The implementation of the method into a web server is available at http://bioinfo2.ugr.es/wordCluster/wordCluster.php webcite including additional features like the detection of co-localization with gene regions or the annotation enrichment tool for functional analysis of overlapped genes. 2014-10-08T06:22:30Z 2014-10-08T06:22:30Z 2011 info:eu-repo/semantics/article Hackenberg, M.; et al. WordCluster: detecting clusters of DNA words and genomic elements. Algorithms for Molecular Biology, 6: 2 (2011). [http://hdl.handle.net/10481/33377] 1748-7188 http://hdl.handle.net/10481/33377 10.1186/1748-7188-6-2 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Biomed Central