Stomach Organ and Cell Lineage Differentiation: From Embryogenesis to Adult Homeostasis

Gastric diseases cause considerable worldwide burden. However, the stomach is still poorly understood in terms of the molecular–cellular processes that govern its development and homeostasis. In particular, the complex relationship between the differentiated cell types located within the stomach and the stem and progenitor cells that give rise to them is significantly understudied relative to other organs. In this review, we highlight the current state of the literature relating to specification of gastric cell lineages from embryogenesis to adulthood. Special emphasis is placed on substantial gaps in knowledge about stomach specification that we think should be tackled to advance the field. For example, it has long been assumed that adult gastric units have a granule-free stem cell that gives rise to all differentiated lineages. Here, we point out that there are also other models that fit all extant data, such as long-lived, lineage-committed progenitors that might serve as a source of new cells during homeostasis.