UCLA

Stem cell maintenance in the small intestine in vertebrates has been well studied, though many factors involved in that process are still unknown. This study focuses on the development of the visceral muscle and intestinal tissues of Drosophila melanogaster during metamorphosis in order to further explain the intestinal stem cell/niche environment. Through stage wise dissection and immunohistochemical assays we were able to determine, (1) the adult posterior midgut is formed by cells of the anterior hindgut. (2) The visceral muscle de-differentiates and re-differentiates in a step wise manner during metamorphosis. (3) The presumptive intestinal stem cells (pISCs) of the midgut undergo many waves of division, are motile, and differentiate to endocrine cell fates at late pupal stages under the control of prospero and notch signaling. (4) A population of pISCs in the posterior midgut migrate past the midgut/hindgut boundary to form the renal stem cells of the adult Malpighian tubules. (5) The development of the midgut and hindgut epithelium during metamorphosis. These findings, taken together provide new understanding of these specific environments that may be applied to their homologous counterparts.