Polymer Model of the Spatial Organization of Interphase Chromosomes in Yeast

Abstract

The spatial organization of chromosomes in cells plays an important role in the biological functions they perform, such as gene regulation and DNA recombination. Recent experiments have measured chromosome organization in yeast during interphase in quantitative detail yielding cell-to-cell distributions of the positions of different genetic loci within the nucleus.These experiments pose a challenge to theoretical models of chromosomes. Using a simple, analytically tractable, polymer model that take into account nuclear confinement and tethering we compute the distributions of telomere positions along the nuclear periphery (ref. 1), and the location of the HML locus on chromosome III (ref. 2), and find good agreements with experimental data. Furthermore, we investigate theoretically the effect of nuclear size, telomere positioning, and chromosome flexibility on the spatial distributions of genetic loci suggesting new experiments for testing polymer models of yeast interphase chromosomes.