Dynamical Modeling of Three-Dimensional Genome Organization in Interphase Budding Yeast

Eukaryotic genome is organized in a set of chromosomes each of which consists of a chain of DNA and associated proteins. Processes involving DNA such as transcription, duplication, and repair, therefore, should be intrinsically related to the three-dimensional organization of the genome. In this article, we develop a computational model of the three-dimensional organization of the haploid genome of interphase budding yeast by regarding chromosomes as chains moving under the constraints of nuclear structure and chromatin-chromatin interactions. The simulated genome structure largely fluctuates with the diffusive movement of chromosomes. This fluctuation, however, is not completely random, as parts of chromosomes distribute in characteristic ways to form territories in the nucleus. By suitably taking account of constraints arising from the data of the chromosome-conformation-capture measurement, the model explains the observed fluorescence data of chromosome distributions and motions.