title: Single-cell analysis reveals functionally distinct classes within the planarian stem cell compartment.
abstract: Planarians are flatworms capable of regenerating any missing body region. This capacity is mediated by neoblasts, a proliferative cell population that contains pluripotent stem cells. Although population-based studies have revealed many neoblast characteristics, whether functionally distinct classes exist within this population is unclear. Here, we used high-dimensional single-cell transcriptional profiling from over a thousand individual neoblasts to directly compare gene expression fingerprints during homeostasis and regeneration. We identified two prominent neoblast classes that we named ζ (zeta) and σ (sigma). Zeta-neoblasts encompass specified cells that give rise to an abundant postmitotic lineage, including epidermal cells, and are not required for regeneration. By contrast, sigma-neoblasts proliferate in response to injury, possess broad lineage capacity, and can give rise to zeta-neoblasts. These findings indicate that planarian neoblasts comprise two major and functionally distinct cellular compartments.
authors.affiliation: Howard Hughes Medical Institute, MIT Biology, Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
authors.forename: Josien C
authors.initials: JC
authors.lastname: van Wolfswinkel
authors.affiliation: Howard Hughes Medical Institute, MIT Biology, Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Wagner
authors.affiliation: Howard Hughes Medical Institute, MIT Biology, Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA. Electronic address: reddien@wi.mit.edu.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Reddien
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002451:Cell Compartmentation; D002453:Cell Cycle; D019070:Cell Lineage; D000078404:Epidermal Cells; D020869:Gene Expression Profiling; D010932:Planarians / Q000166:cytology*; D039904:Pluripotent Stem Cells / Q000166:cytology; D034622:RNA Interference; D012038:Regeneration; D059010:Single-Cell Analysis / Q000379:methods*; D013234:Stem Cells / Q000166:cytology*
chemical_list: D015415:Biomarkers