Fig. 5. Regulatory network model. This reticulated model shows all of the known bHLH and myb transcriptional regulators that function the TTG1-dependent pathways. The model illustrates the potential (broken lines) and demonstrated (unbroken lines) interactions among the proteins and genes, the narrowing of the specificity of the regulatory function as one goes from WD to bHLH to myb, and the redundancies demonstrated at the bHLH and single myb levels.