Neoblast Clusters

A Single-Cell Atlas of cNeoblasts and its Early Progeney

Visual Abstract

Proliferating cells known as neoblasts include pluripotent stem cells (PSCs) that sustain tissue homeostasis and regeneration of lost body parts in planarians. However, the lack of markers to prospectively identify and isolate these adult PSCs has significantly hampered their characterization. We used single-cell RNA sequencing (scRNA-seq) and single-cell transplantation to address this long-standing issue. Large-scale scRNA-seq of sorted neoblasts unveiled a novel subtype of neoblast (Nb2) characterized by high levels of PIWI-1 mRNA and protein and marked by a conserved cell-surface protein-coding gene, tetraspanin 1 (tspan-1). tspan-1-positive cells survived sub-lethal irradiation, underwent clonal expansion to repopulate whole animals, and when purified with an anti-TSPAN-1 antibody, rescued the viability of lethally irradiated animals after single-cell transplantation. The first prospective isolation of an adult PSC bridges a conceptual dichotomy between functionally and molecularly defined neoblasts, shedding light on mechanisms governing in vivo pluripotency and a source of regeneration in animals.

Use the search box to the right to view expression of a transcript in the Neoblast Clusters. If you need to translate the transcript ID to the SMED300XXXXX format, use the Rosetta Stone Transcript Mapper

View a sample gene page: SMED30008639

Proposed Lineage Composition Model of Planarian piwi-1+ Cells

12 major classes representing 6 cell lineages of all 3 germ layers were found in the neoblast compartment of adult Planaria. Nb2 and SL6a can self-renew and collectively give rise to a wide range of tissue types in single-cell transplantation and repopulation, respectively. As differentiation ensues, piwi-1 expression is downregulated and tissue-associated transcription factors upregulated.