Expression Profiles of Planarain Stem Cells and their Immediate Division Progeny
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ABSTRACT:
ORGANISM(S): Schmidtea mediterranea
PROVIDER: GSE11503 | GEO | 2008/09/12
SECONDARY ACCESSION(S): PRJNA106325
REPOSITORIES: GEO
Similar Datasets
Project description:Throughout adulthood, the replacement of cells lost to physiological turnover or injury in planarians is sustained by the proliferation and differentiation of adult stem cells known as neoblasts. Because neoblasts are the only known mitotic cells in asexual planarians, they can be efficiently eliminated by irradiation without significantly affecting post-mitotic differentiated cells. We uncovered a cohort of transcripts specific to the stem cells and their division progeny by defining the expression profiles of wild type and irradiated animals at different time points after irradiation. RNA from wild type animals, or from animals 24 hours or seven days after exposure to radiation, were compared to a common reference.
2008-09-12 | E-GEOD-11503 | biostudies-arrayexpress
Project description:The goal of the study was to identify genes expressed in the proliferative cell population (neoblasts) of adult planarians. Proliferating cells are rapidly and specifically eliminated following lethal irradiation. Genes expressed by neoblasts, therefore, were expected to show decreased level of expression following 6,000 rads, relative to control animals.
2012-01-10 | GSE34969 | GEO
Project description:The goal of the study was to identify genes expressed in the proliferative cell population (neoblasts) of adult planarians. Proliferating cells are rapidly and specifically eliminated following lethal irradiation. Genes expressed by neoblasts, therefore, were expected to show decreased level of expression following 6,000 rads, relative to control animals. Total RNA was collected from control (unirradiated) animals and from animals 6, 12, 24, and 48 hours following 6,000 rads irradiation. Between three and five replicates were used for each sample
2012-01-10 | E-GEOD-34969 | biostudies-arrayexpress
Project description:The goal of this experiment is to identify target genes of Egf signaling which regulate recovery of the neoblast population following exposure to a sublethal dose of radiation. A large population of highly proliferative stem cells (neoblasts) is required for physiological tissue homeostasis and regeneration after injury in planarians. Recent studies indicate that survival of a few neoblasts after sublethal irradiation results in the clonal expansion of the surviving stem cells and the eventual restoration of tissue homeostasis and regenerative capacity. Many genes are known to be required for the normal function of neoblasts, but the precise mechanisms regulating the population dynamics of these adult pluripotent stem cells remain largely unknown. By coupling RNAi screening and sublethal irradiation, we uncovered a central role for Epidermal Growth Factor (EGF) signaling during in vivo neoblast expansion mediated by Smed-egfr-3 (egfr-3) and its putative ligand Smed-neuregulin-7 (nrg-7). Furthermore, the EGFR-3 protein localizes asymmetrically on the cytoplasmic membrane of neoblasts and the ratio of asymmetric to symmetric cell divisions decreases significantly in egfr-3(RNAi) worms. Our results not only provide the first molecular evidence of asymmetric stem cell divisions in planarian, but also demonstrate that EGF signaling likely functions as an essential regulator of neoblast clonal expansion.
2016-08-18 | GSE84025 | GEO
Project description:Proliferating cells known as neoblasts include pluripotent stem cells (PSCs) capable of sustaining 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 fluorescently 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 (tspan1). tspan1-positive cells survived sub-lethal irradiation, underwent clonal expansion to repopulate whole animals, and when purified with an anti-TSPAN-1 antibody rescued with high efficiency the viability of lethally irradiated animals after single-cell transplantation. Our work demonstrates the first prospective isolation of an adult PSC, bridges a conceptual dichotomy between operationally and molecularly defined neoblasts, and sheds light on the mechanisms governing in vivo pluripotency and the source of regeneration in planarians.
2018-06-14 | GSE107873 | GEO
Project description:Proliferating cells known as neoblasts include pluripotent stem cells (PSCs) capable of sustaining 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 fluorescently 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 (tspan1). tspan1-positive cells survived sub-lethal irradiation, underwent clonal expansion to repopulate whole animals, and when purified with an anti-TSPAN-1 antibody rescued with high efficiency the viability of lethally irradiated animals after single-cell transplantation. Our work demonstrates the first prospective isolation of an adult PSC, bridges a conceptual dichotomy between operationally and molecularly defined neoblasts, and sheds light on the mechanisms governing in vivo pluripotency and the source of regeneration in planarians.
2018-06-14 | GSE107874 | GEO
Project description:Adult stem cells are tissue-specific cells with the capacity to self-renew and differentiate to continually replace cells lost to normal physiological turnover or injury. Neoblasts, the planarian stem cells, are widely distributed throughout the body mesenchyme, driving constitutive renewal of tissues during homeostasis and endowing planarians with the remarkable capacity to regenerate wholly from tiny tissue fragments. Neoblasts are the only dividing cells in planarians and are believed to be collectively comprised of both a heterogeneous population of pluripotent cells with broad differentiation potential and also lineage-committed progenitor cells that give rise to specific tissues. Recent work has identified a prominent class of neoblasts referred to as zeta-class, which express the zinc-finger gene zfp-1. Zfp-1, along with the chromatin remodeling factor chd4, the tumor suppressor gene p53, and most recently an RNA-binding protein mex3-1, have all been shown to be required for maintenance of two related post-mitotic, sub-epidermal cell populations expressing the specific marker genes prog-1 and AGAT-1, which have been widely used to asses neoblast differentiation. Given that zeta-class neoblasts are required for the generation of prog-1 and AGAT-1 positive cells and other markers of epidermal cell types, prog-1 and AGAT-1 likely mark two major populations of epidermal progeny cells. To understand the molecular mechanisms underlying neoblast differentiation and how they give rise to multiple cell types, we devised a strategy to identify critical factors enriched in the AGAT-1 positive cell population required for epidermal lineage progression. We performed RNA-Seq analysis of chd4 and p53 RNAi animals and characterized additional markers enriched in AGAT-1 positive and related post-mitotic cells.
2015-10-21 | GSE72389 | GEO
Project description:Freshwater planarian flatworms possess uncanny regenerative capacities mediated by abundant and collectively totipotent adult stem cells. Key functions of these cells during regeneration and tissue homeostasis have been shown to depend on PIWI, a molecule required for piRNA expression in planarians. Nevertheless, the full complement of piRNAs, and microRNAs (miRNAs) in this organism has yet to be defined. Here, we report on the large scale cloning and sequencing of small RNAs from the planarian Schmidtea mediterranea, yielding altogether millions of sequenced unique small RNAs. We show that piRNAs are in part organized in genomic clusters and that they share characteristic features with mammalian and fly piRNAs. We further identify 61 novel miRNA genes and thus double the number of known planarian miRNAs. Sequencing, as well as quantitative PCR of small RNAs uncovered ten miRNAs enriched in planarian stem cells. These miRNAs are down-regulated in animals in which stem cells have been abrogated by irradiation, and thus constitute miRNAs likely associated with specific stem cell functions. Altogether, we present the first comprehensive small RNA analysis in animals belonging to the third animal superphylum, the Lophotrochozoa, and single out a number of miRNAs that may function in regeneration. Several of these miRNAs are deeply conserved in animals. Small RNAs were sequenced from FACS-sorted neoblast stem cells, untreated planarians and irradiated planarians, depleted of neoblasts
2009-06-30 | E-GEOD-16159 | biostudies-arrayexpress
Project description:The transcriptome of the planarian Schmidtea mediterranea is not well characterized. We have used RNA-Seq to characterize the transcriptome in both sexual and asexual strains of S. mediterranea from both untreated and irradiated animals. Moreover, we have performed RNA-Seq on RNA purified from FACS sorted neoblasts and differentiated cells. Together these studies expand our understanding of the planarian transcriptome and have identified strain-specific, neoblast-specific, and conserved transcripts. RNA-Seq was performed on RNA isolated from untreated and irradiated S. mediterranea animals from both the sexual and asexual strains, on FACS purified X1 neoblasts, X2 neoblasts, and Xins differentiated cells. One of the raw data files for GSM847465 is missing. The fasta file is provided at http://genome.vcell.uchc.edu/GenomeData02/Graveley_Lab_Public_Data/Planarian/S.mediterranea_SexNIRmRNA3.fa.gz
2012-04-24 | E-GEOD-34326 | biostudies-arrayexpress
Project description:Adult stem cells are tissue-specific cells with the capacity to self-renew and differentiate to continually replace cells lost to normal physiological turnover or injury. Neoblasts, the planarian stem cells, are widely distributed throughout the body mesenchyme, driving constitutive renewal of tissues during homeostasis and endowing planarians with the remarkable capacity to regenerate wholly from tiny tissue fragments. Neoblasts are the only dividing cells in planarians and are believed to be collectively comprised of both a heterogeneous population of pluripotent cells with broad differentiation potential and also lineage-committed progenitor cells that give rise to specific tissues. Recent technology has allowed one to isolate stem cells so we used a well-established method to isolate planarian stem cells by Hoechst blue staining and flow cytometry. To understand the molecular mechanisms underlying neoblast differentiation, we performed an RNA-Seq analysis of X1 and Xins cells looking at the differentially expressed genes between the two populations. Examine gene expression profiles of adult flatwormâ??s X1 and Xins cell types. The experiment was performed in quadruplicate yielding a total of 8 samples.
2015-12-17 | E-GEOD-73027 | biostudies-arrayexpress