The Drosophila adult midgut progenitor cells arise from asymmetric divisions of neuroblast-like cells

The Drosophila adult midgut progenitor cells (AMPs) give rise to all cells in the adult midgut epithelium, including the intestinal stem cells (ISCs). While they share many characteristics with the ISCs, it remains unclear how they are generated in the early embryo. Here, we show that they arise from a population of endoderm cells, which exhibit multiple similarities with Drosophila neuroblasts. These cells, which we have termed endoblasts, are patterned by homothorax (Hth) and undergo asymmetric divisions using the same molecular machinery as neuroblasts. We also show that the conservation of this molecular machinery extends to the generation of the enteroendocrine lineages. Parallels have previously been drawn between the pupal ISCs and larval neuroblasts. Our results suggest that these commonalities exist from the earliest stages of specification of progenitor cells of the intestinal and nervous systems and may represent an ancestral pathway for multipotent progenitor cell specification.