FIGURE 7.

Gene regulatory network of heterocyst differentiation. The main elements and their interactions are depicted schematically, together with other relevant elements with either more dubious (in light red background) or oversimplified roles (in light blue background) in the scheme. AHetR stands for the active form of HetR. The ellipse represents the differentiation into a heterocyst. Arrows with solid lines represent interactions between elements. Arrows with dashed–dotted lines represent post-transcriptional changes. Regular and bold formatted references indicate phenotypically inferred and observed molecular interactions, respectively. Discussing all the references contained in this figure, which describe experimental results, is out of the scope of this work. For this reason, a number of them are not cited in the text.