Figures & data
Figure 1. Chromatin “pre-pattern” and epigenetic modulation during liver and pancreas specification. In undifferentiated endoderm cells, the poised liver and pancreas regulatory elements have distinct chromatin “pre-patterns.” The pioneer factors of FoxA and GATA4/6 occupy liver regulatory elements, which have low or undetectable levels of the positive (H3K9acK14ac) and negative (H3K27me3) chromatin marks. By contrast, the pancreas regulatory elements of the Pdx1 gene, except for area IV, contain both marks. BMP signaling induces SMAD4 to recruit P300 to the liver elements, stimulating histone acetylation there and promoting liver specification. During this period, EZH2 restricts the specification of pancreas progenitors.
