The ERC-funded laboratory of Christof Niehrs studies regulatory DNA and RNA modifications, which play important roles in development & disease. We utilize highly sensitive mass spectrometry (Triple Quadrupole Mass Spec) and stable isotope metabolic labelling to profile epigenetic and epitranscriptomic changes, including 5mC, 5hmC, 5fC, 5caC, m6A, and others. The successful candidate will study nucleic acid modifying enzymes to unravel how chemical modifications in DNA, RNA and Rloops regulate pluripotency and differentiation of mammalian embryonic stem cells and embryos. You will use mass spectrometry, as well as genome-edited CRISPR/Cas9 stem cell mutants, as well as various NGS protocols to carry out a multidimensional analysis to address: Which modifications can be identified and how do they change with different cellular states? Where in the genome and in which RNAs do the modifications occur? What are molecular determinants involved in targeting of modifications to specific sites? The project will involve strong interaction with computational biologists.