Professor Rainer Sachs Mathematical modeling of large-scale DNA structure and of gene expression patterns 1. We have current projects on applications of geometry, topology, stochastic process theory and computer simulation to topological and radiobiological data on large-scale chromatin structure. Radiobiology studies ionizing radiation damage, mainly DNA double strand breaks which may be misrepaired and cause, e.g., cell death or genomic alterations which lead to cancer. Topological methods can analyze changes in DNA geometry and topology to characterize a range of biochemical reactions such as recombination and DNA packing.
Recombination is used by nature to modify the genetic code of organisms.
It plays an important role in a number of biological processes including integration of viral DNA into the host genome. DNA packing involves geometric arrangements that allow organisms to store large DNA molecules in confined volumes such as cellular nuclei or viral capsids. Gene Expression Patterns. Our group is starting to analyze gene expression patterns. When cells undergo external perturbations, they react by changing transcription levels of some genes.