Figure 1.

Model of Snai1 action in the mouse gut and of Esg in fly ISCs

(A) Snai1 is expressed in CBCs and transit amplifying cells. It regulates CBC survival and differentiation of transit amplifying cells to the secretory or absorptive lineage. (B) Esg is found in ISCs and EBs in the fly gut, where it acts to repress differentiation genes. Moreover, it may activate self-renewal genes in ISCs. Finally, amun is a target of Esg in EBs, where it affects N signalling to determine EC versus EE fate.