**
Below is the ascii version of the abstract for 13-79.
The html version should be ready soon.**Jomar F. Rabajante, Cherryl O. Talaue, Baltazar D. Aguda
Mathematical Analysis of a Multistable Switch Model of Cell Differentiation
(1931K, PDF)
ABSTRACT. Non-binary simultaneous decision network of gene regulation represents a cell differentiation process that involves more than two possible cell lineages. The simultaneous decision network is an alternative to the hierarchical models of gene regulation and it exhibits possible presence of multistable master switches. To investigate the qualitative behavior of the dynamics of the simultaneous decision network, we employ geometric techniques in the analysis of the network's corresponding system of ordinary differential equations (ODE). We determine the location and the maximum number of equilibrium points given a set of parameter values. Our analysis shows that the solution to the ODE model always converge to a stable equilibrium point. Varying the values of some parameters, such as the degradation rate and the amount of exogenous stimulus, can decrease the size of the basin of attraction of an undesirable steady state as well as increase the size of the basin of attraction of a desirable steady state. A sufficient change in some parameter values can silence or reactivate gene transcription that results to cell fate switching without the aid of stochastic noise. We further show that increasing the amount of exogenous stimulus can shutdown multistability of the system such that only one stable equilibrium point remains.