Title: Modeling Epigenetic Silencing
Abstract: We formulate a mathematical version of the conventional model
of maintenance of silencing in S. cerevisiae and analyze the conditions
for bistability as well as for formation of stationary boundaries.
Although the model is perhaps too simple, the structure of the
bifurcation diagram, describing parameter regions with different kinds
of qualitative behavior, is likely to be more robust. We can place some
of the known mutants in different regions of this diagram. One
interesting finding of this study is that, under some conditions, the
lowering of acetylation rates might have non-obvious consequences for
silencing. Possible improvements of the model as well as experimental
tests are discussed at the end.