Figure 1.

The regulatory network that specifies and differentiates the C. elegans endoderm consists of a cascade of 4 GATA-type transcription factors: END-3, END-1, ELT-7 and ELT-2 in order of appearance. The time scale of early C. elegans embryogenesis is shown at left (minutes at 20°C after the first cell division). In the center are shown 3 differential interference contrast images of early C. elegans embryos, at the 1E, 2E and 4E cell stage from top to bottom; E cell nuclei are marked with white dots. Arrows indicate both proposed and established regulatory relations between the 4 GATA factors, as well as between the 4 GATA factors and genes expressed in the differentiated intestine. (From Wiesenfahrt et al.⁴).