Pluripotency, Differentiation, and Reprogramming: A Gene Expression Dynamics Model with Epigenetic Feedback Regulation
Fig 11
Time series of gene expression in reprogramming via overexpression of three genes and one external factor.
Plotted here are time series of gene expression for x1, x2, x3, x4, x5, and the epigenetic threshold variables θ15. In this case, we used the following parameter set: θ13(0) = θ34(0) = θ43(0) = 0.65, θ15(0) = θ31(0) = θ21(0) = θ51(0) = θ42(0) = 1.0. In the differentiated state, we overexpressed genes x1, x2, and x5 over a long period and added one external regulator. Induction of these factors changed the epigenetic threshold variables; gene expression then began to oscillate again and, later, differentiation occurred in a few cells.