title: Migration of Drosophila intestinal stem cells across organ boundaries.
abstract: All components of the Drosophila intestinal tract, including the endodermal midgut and ectodermal hindgut/Malpighian tubules, maintain populations of dividing stem cells. In the midgut and hindgut, these stem cells originate from within larger populations of intestinal progenitors that proliferate during the larval stage and form the adult intestine during metamorphosis. The origin of stem cells found in the excretory Malpighian tubules ('renal stem cells') has not been established. In this paper, we investigate the migration patterns of intestinal progenitors that take place during metamorphosis. Our data demonstrate that a subset of adult midgut progenitors (AMPs) move posteriorly to form the adult ureters and, consecutively, the renal stem cells. Inhibiting cell migration by AMP-directed expression of a dominant-negative form of Rac1 protein results in the absence of stem cells in the Malpighian tubules. As the majority of the hindgut progenitor cells migrate posteriorly and differentiate into hindgut enterocytes, a group of the progenitor cells, unexpectedly, invades anteriorly into the midgut territory. Consequently, these progenitor cells differentiate into midgut enterocytes. The midgut determinant GATAe is required for the differentiation of midgut enterocytes derived from hindgut progenitors. Wingless signaling acts to balance the proportion of hindgut progenitors that differentiate as midgut versus hindgut enterocytes. Our findings indicate that a stable boundary between midgut and hindgut/Malpighian tubules is not established during early embryonic development; instead, pluripotent progenitor populations cross in between these organs in both directions, and are able to adopt the fate of the organ in which they come to reside.
authors.affiliation: Department of Molecular Cell and Developmental Biology, University of California-Los Angeles, CA 90095, USA.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takashima
authors.forename: Manash
authors.initials: M
authors.lastname: Paul
authors.forename: Patrick
authors.initials: P
authors.lastname: Aghajanian
authors.forename: Amelia
authors.initials: A
authors.lastname: Younossi-Hartenstein
authors.forename: Volker
authors.initials: V
authors.lastname: Hartenstein
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D002465:Cell Movement; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000378:metabolism; D004475:Ectoderm / Q000166:cytology / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D047108:Embryonic Development; D004707:Endoderm / Q000166:cytology / Q000378:metabolism; D020895:Enterocytes / Q000166:cytology / Q000378:metabolism; D050980:GATA Transcription Factors / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005838:Genotype; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology*; D008317:Malpighian Tubules / Q000166:cytology / Q000378:metabolism*; D008675:Metamorphosis, Biological; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D014513:Ureter / Q000166:cytology / Q000378:metabolism; D051155:Wnt1 Protein / Q000235:genetics / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D050980:GATA Transcription Factors; C499641:GATAe protein, Drosophila; C090146:Rac1 protein, Drosophila; D051155:Wnt1 Protein; C074622:wg protein, Drosophila; D020744:rac GTP-Binding Proteins