Planarian stem cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Dugesia japonica
PROVIDER: GSE5318 | GEO | 2006/07/19
SECONDARY ACCESSION(S): PRJNA96405
REPOSITORIES: GEO
Similar Datasets
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:Many long-lived species of animals require the function of adult stem cells throughout their lives. However, the transcriptomes of stem cells in invertebrates and vertebrates have not been compared, and consequently ancestral regulatory circuits that control stem cell populations remain poorly defined. In this study, we have used data from high-throughput RNA sequencing (RNA-Seq) to compare the transcriptomes of pluripotent adult stem cells from planarians with the transcriptomes of human and mouse pluripotent embryonic stem cells. From a stringently-defined set of 4,432 orthologs shared between planarians, mice and humans, we identified 123 conserved genes that are ≥ 5-fold differentially expressed in stem cells from all three species. Guided by this gene set, we used RNAi screening in adult planarians to discover novel stem cell regulators, which we found to affect the stem cell-associated functions of tissue homeostasis, regeneration, and stem cell maintenance. Examples of genes that disrupted these processes included the orthologs of TBL3, PSD12, TTC27, and RACK1. From these analyses, we concluded that by comparing stem cell transcriptomes from diverse species, it is possible to uncover conserved factors that function in stem cell biology. These results provide insights into which genes composed the ancestral circuitry underlying the control of stem cell self-renewal and pluripotency. Three planarian tissues were analyzed: stem cells, stem cell progeny, and differentiated tissues. For the manuscript: Labbe, RM, et. al., 2012, Stem Cells
2012-06-01 | E-GEOD-37910 | biostudies-arrayexpress
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: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.
2008-09-12 | GSE11503 | GEO
Project description:Many long-lived species of animals require the function of adult stem cells throughout their lives. However, the transcriptomes of stem cells in invertebrates and vertebrates have not been compared, and consequently ancestral regulatory circuits that control stem cell populations remain poorly defined. In this study, we have used data from high-throughput RNA sequencing (RNA-Seq) to compare the transcriptomes of pluripotent adult stem cells from planarians with the transcriptomes of human and mouse pluripotent embryonic stem cells. From a stringently-defined set of 4,432 orthologs shared between planarians, mice and humans, we identified 123 conserved genes that are ≥ 5-fold differentially expressed in stem cells from all three species. Guided by this gene set, we used RNAi screening in adult planarians to discover novel stem cell regulators, which we found to affect the stem cell-associated functions of tissue homeostasis, regeneration, and stem cell maintenance. Examples of genes that disrupted these processes included the orthologs of TBL3, PSD12, TTC27, and RACK1. From these analyses, we concluded that by comparing stem cell transcriptomes from diverse species, it is possible to uncover conserved factors that function in stem cell biology. These results provide insights into which genes composed the ancestral circuitry underlying the control of stem cell self-renewal and pluripotency.
2012-06-01 | GSE37910 | GEO
Project description:Neoblasts are adult stem cells (ASCs) in planarians which sustain cell replacement during homeostasis and regeneration of any missing tissue. While numerous studies have examined genes underlying neoblast pluripotency, molecular pathways driving the postmitotic fate remain poorly defined. Here we used transcriptional profiling of irradiation-sensitive and -insensitive cell populations and RNA interference (RNAi) functional screening to uncover markers and regulators of postmitotic progeny. We identified 32 new markers, which distinguish two epithelial progenitor populations, and a planarian homolog to the MEX3 RNA-binding protein (Smed-mex3-1) as a key regulator of lineage progression. mex3-1 is required for generating progenitors of epithelial, neural, eye, pharyngeal, and protonephridial lineages, and restricting expansion of the stem cell compartment. We also demonstrate the utility of using mex3-1(RNAi) animals to identify additional progenitor markers. These results show that mex3-1 promotes differentiation in multiple, if not all, lineages, and maintains the balance between ASC self-renewal and commitment. Sorted and irradiated animals were collected as previously described (Labbe, et al., 2012) and RNAi conditions were triplicated, RNA was purified independently, then each replicate was pooled in equal amounts for sequencing at the timepoint: 1 feed day 12 for control RNAi and mex3-1 RNAi.
2015-06-15 | E-GEOD-68581 | 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
Project description:Neoblasts are adult stem cells (ASCs) in planarians which sustain cell replacement during homeostasis and regeneration of any missing tissue. While numerous studies have examined genes underlying neoblast pluripotency, molecular pathways driving the postmitotic fate remain poorly defined. Here we used transcriptional profiling of irradiation-sensitive and -insensitive cell populations and RNA interference (RNAi) functional screening to uncover markers and regulators of postmitotic progeny. We identified 32 new markers, which distinguish two epithelial progenitor populations, and a planarian homolog to the MEX3 RNA-binding protein (Smed-mex3-1) as a key regulator of lineage progression. mex3-1 is required for generating progenitors of epithelial, neural, eye, pharyngeal, and protonephridial lineages, and restricting expansion of the stem cell compartment. We also demonstrate the utility of using mex3-1(RNAi) animals to identify additional progenitor markers. These results show that mex3-1 promotes differentiation in multiple, if not all, lineages, and maintains the balance between ASC self-renewal and commitment.
2015-06-15 | GSE68581 | GEO
Project description:Epimorphic regeneration commonly relies on the activation of quiescent stem cells to drive new cell production. The planarian Schmidtea mediterranea is among the best regenerators in nature, thanks to its large population of adult stem cells, called neoblasts. While neoblasts have long been known to drive regeneration, whether a subset of neoblasts is reserved for this purpose is unknown. Here, we revisited the idea of reserved neoblasts by approaching neoblast heterogeneity from a regulatory perspective. By implementing a new fluorescence-activated cell sorting strategy in planarians, we identified a population of neoblasts defined by low transcriptional activity. These RNAlow neoblasts are relatively slow-cycling at homeostasis and undergo a morphological regeneration response characterized by cell growth at 48 hours post-amputation. At this time, RNAlow neoblasts proliferated in a TOR-dependent manner. Additionally, knockdown of the tumour suppressor Lrig-1, which is enriched in RNAlow neoblasts, resulted in RNAlow neoblast growth and hyperproliferation at homeostasis, and ultimately delayed regeneration. We propose that slow-cycling RNAlow neoblasts represent a regeneration-reserved neoblast population.
2020-12-31 | GSE157860 | GEO
Project description:We have developed an accurate and reliable mass-spectra-based proteomics approach to complement previous genomic studies and to further achieve a more accurate understanding and description of the molecular and cellular processes related to the neoblasts.
2012-03-05 | PRD000350 | Pride