Gut stem cells, a story of snails, flies and mice

Abstract

Intestinal stem cells (ISCs) replenish and regenerate several types of cells in the gut, both during normal homeostasis and in response to various insults such as infections. Although gut structure and complexity vary across phyla, two functional categories of differentiated cell types are always present: absorptive cells and those of the secretory lineage. A series of studies in Drosophila and mouse published in The EMBO Journal, including one in this issue, identifies conserved roles for the Snail family of zinc finger transcription factors in regulating self-renewal and differentiation of ISCs (Korzelius et al, 2014; Loza-Coll et al, 2014; Horvay et al, 2015).

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.