Research

The Walter group investigates transcriptional (RNA-Seq) and epigenetic changes at cellular and organismal levels and develops and uses NGS-based methods with a focus on DNA methylation (WGBS, RRBS, Hairpin-BS, Ox-BS) and chromatin analysis (NOME-Seq, ATAC-Seq, and ChIP-Seq). The lab has its own sequencing unit (HiSeq2500, Mi-Seq, Nextseq-500) and develops bioinformatics methods for data analysis. Additionally, the group is an associated partner in the West German Sequencing Center of the DFG. Complementary to NGS, the group uses the Illumina 850K bead array technology for extensive EWAS studies.

Core questions of NGS/array-based research are:

- How are genomes epigenetically programmed during development and differentiation?
- How variable are these events at the single-cell level?
- Which enzymatic processes control epigenetic dynamics and inheritance?
- What specific epigenetic changes are found in diseased cells, and can they be used for personalized diagnostics?

DNA methylation is an epigenetic modification of certain cytosine bases in the genome. Each human celltype has its own pattern of methylated cytosine bases in the genome. DNA methylation can also be further modified by oxidation. The various forms and distributions of DNA methylation control cell-specific chromatin structures and the expression of genes. Therefore, DNA methylation represents a lasting epigenetic memory of cells.

The ordered distribution of DNA methylation in the genome of differentiating cells is essential for proper development. Changes in DNA methylation patterns and mutations in enzymes that set, further modify, recognize, "read," or remove DNA methylation are involved in the development of various human diseases. The causes of these misregulations are currently under intensive investigation.