Category Archives: daniela-beisser

28.07.2016 | Poster and Workshop at ECCB

A second poster from our working group will be presented at ECCB 2016. Daniela Beisser will present a poster about Taxonomic assignment of protist metatranscriptome sequences. She will also present the topic during the ECCB workshop “W11 – Recent Computational Advances in Metagenomics (RCAM’16)” on 4th September. See the workshop website for more information.

Taxonomic assignment of protist metatranscriptome sequences
Daniela Beisser, Nadine Graupner, Lars Grossmann, Jens Boenigk and Sven Rahmann

Next generation sequencing (NGS) technologies are increasingly applied to analyse complex microbial ecosystems by mRNA sequencing of whole communities, also known as metatranscriptome sequencing. In principle, each sequenced mRNA allows to both identify the species of origin and assign a function to the transcribed gene. While the functional information is sufficiently covered by databases such as Uniprot, NCBI, KEGG and many others, species identification is currently limited by incomplete reference databases. Inferring the community composition from metratranscriptomic samples is thus still a difficult problem. At the moment, most analyses are restricted to prokaryotic communities, which enjoy better database coverage, or to communities of few known species with sequenced genomes, or to a combination of rRNA and mRNA sequencing. However, the latter approach does not allow to link taxonomic and functional information directly.

Our approach focuses on an accurate assignment of taxonomic groups to metatranscriptomic reads. We constructed a custom database that comprises all major eukaryotic groups, developed a stand-alone tool to assign reads with a low false discovery rate and created a workflow for complete metatranscriptome analysis. The workflow covers all bioinformatic steps: preprocessing of the raw data, taxonomic and functional assignment, and visualisation of the results.

05.07.2016 | Article about epigenetics of monocyte to macrophage differentiation accepted in “Epigenetics & Chromatin”

Christopher Schröder, Daniela Beißer and Sven Rahmann from the Genome Informatics group contributed to novel insights about epigenetic changes during cell differentiation. The article will appear soon in the renowned “Epigenetics & Chromatin” journal (IF 4.873) by BioMedCentral.

Epigenetic dynamics of monocyte to macrophage differentiation
by Stefan Wallner, Christopher Schröder, Elsa Leitão, Tea Berulava, Claudia
Haak, Daniela Beißer, Sven Rahmann, Andreas S Richter, Thomas Manke,
Ulrike Böhnisch, Laura Arrigoni, Sebastian Fröhler, Filippos Klironomos,
Wei Chen, Nikolaus Rajewsky, Fabian Müller, Peter Ebert, Thomas
Lengauer, Matthias Barann, Philip Rosenstiel, Gilles Gasparoni, Karl
Nordström, Jörn Walter, Benedikt Brors, Gideon Zipprich, Bärbel Felder,
Ludger Klein-Hitpass, Corinna Attenberger, Gerd Schmitz, Bernhard Horsthemke

Monocyte to macrophage differentiation involves major biochemical and
structural changes. In order to elucidate the role of gene regulatory
changes during this process, we used high-throughput sequencing to
analyze the complete transcriptome and epigenome of human monocytes that
were differentiated in vitro by addition of colony stimulating factor 1
(CSF1) in serum-free medium. Numerous mRNAs and miRNAs were
significantly up- or downregulated. More than 100 discrete DNA regions,
most often far away from transcription start sites, were rapidly
demethylated by the ten-eleven translocation (TET) enzymes, became
nucleosome-free and gained histone marks indicative of active enhancers.
These regions were unique for macrophages and associated with genes
involved in the regulation of the actin cytoskeleton, phagocytosis and
innate immune response. In summary, we have discovered a phagocytic gene
network that is repressed by DNA methylation in monocytes and rapidly
de-repressed after the onset of macrophage differentiation.

Poster at GCB 2015 on mutational landscapes of relapsing neuroblastoma

Bioinformatics Analysis of Heterogenous Data Reveals Characteristic Mutational Landscapes of Neuroblastoma Relapses, GCB 2015 in Dortmund

Marc Schunb-posterlte, Johannes Köster, Daniela Beisser, Corinna Ernst, Christopher Schröder, Alexander Schramm and Sven Rahmann

Neuroblastoma is a malignancy of the developing sympathic nervous system that causes 15% of childhood cancer-related mortality. However, in the vast majority of cases death results not from the initial disease manifestation but rather from metastasis or recurrence.

Systematic search for genomic alterations in primary neuroblastomas has shown low genetic complexity, with significant mutations in only a very few genes. This study explored the genomic landscape of relapsing neuroblastoma in order to evaluate ‘driver’ mutations to be exploited as therapeutic targets.