Transcriptional Dynamics of the Embryonic Stem Cell Switch
Figure 1
The Core Transcriptional Network of the ES Cell
Genes and proteins are represented as single entities. Each outgoing arrow represents a protein (the outgoing merging arrows from OCT4 and SOX2 represent complex formation). Each ingoing arrow represents a protein with a role as a TF. Signals A+, e.g., the wnt signaling protein, triggers the system to sustain self-renewal and pluripotency, whereas signals B−, e.g., p53, shuts it off, thereby leading to differentiation. It should be noted that there are also signals A− that repress OCT4 and SOX2. These variants are not shown here since the effects will be similar to those of B−. OCT4, SOX2, and NANOG individually as well as jointly target stem cell and differentiation genes. We model the set of TGs that are jointly regulated by OCT4, SOX2, and NANOG. The nature of the regulation at the TGs is not specified, since we explore all the possibilities. However, the final effect of the regulation is indicated.