title: SMEDWI-2 is a PIWI-like protein that regulates planarian stem cells.
abstract: We have identified two genes, smedwi-1 and smedwi-2, expressed in the dividing adult stem cells (neoblasts) of the planarian Schmidtea mediterranea. Both genes encode proteins that belong to the Argonaute/PIWI protein family and that share highest homology with those proteins defined by Drosophila PIWI. RNA interference (RNAi) of smedwi-2 blocks regeneration, even though neoblasts are present, irradiation-sensitive, and capable of proliferating in response to wounding; smedwi-2(RNAi) neoblast progeny migrate to sites of cell turnover but, unlike normal cells, fail at replacing aged tissue. We suggest that SMEDWI-2 functions within dividing neoblasts to support the generation of cells that promote regeneration and homeostasis.
authors.affiliation: Howard Hughes Medical Institute, Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Reddien
authors.forename: Néstor J
authors.initials: NJ
authors.lastname: Oviedo
authors.forename: Joya R
authors.initials: JR
authors.lastname: Jennings
authors.forename: James C
authors.initials: JC
authors.lastname: Jenkin
authors.forename: Alejandro
authors.initials: A
authors.lastname: Sánchez Alvarado
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D002455:Cell Division; D002465:Cell Movement; D002469:Cell Separation; D048430:Cell Shape; D019926:Cyclin B / Q000235:genetics; D005434:Flow Cytometry; D015870:Gene Expression; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics / Q000502:physiology*; D006706:Homeostasis; D008938:Mitosis; D008969:Molecular Sequence Data; D010641:Phenotype; D010932:Planarians / Q000737:chemistry / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D034622:RNA Interference; D012038:Regeneration; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*
chemical_list: D019926:Cyclin B; D015801:Helminth Proteins