Schmidtea mediterranea
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ABSTRACT:
PROVIDER: PRJNA297689 | ENA |
REPOSITORIES: ENA
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Project description:Background: Freshwater planarians are well known for their regenerative abilities. Less well known is how planarians maintain spatial patterning in long-lived adult animals or how they re-pattern tissues during regeneration. HOX genes are good candidates to regulate planarian spatial patterning, yet the full complement or genomic clustering of planarian HOX genes has not yet been described, primarily because only a few have been detectable by in situ hybridization, and none have given morphological phenotypes when knocked down by RNAi. Results: Because the planarian Schmidtea mediterranea (S. med) is unsegmented, appendage-less, and morphologically simple, it has been proposed that it may have a simplified HOX gene complement. Here we argue against this hypothesis and show that S. med has a total of 13 HOX genes, which represent homologs to all major axial categories, and can be detected by whole-mount in situ hybridization using a highly-sensitive method. In addition, we show that planarian HOX genes do not cluster in the genome, yet 5/13 have retained aspects of axially-restricted expression. Finally, we confirm HOX gene axial expression by RNA-deep-sequencing 6 anterior-to-posterior “zones” of the animal, which we provide as a dataset to the community to discover other axially-restricted transcripts. Conclusions: Freshwater planarians have an unappreciated HOX gene complexity, with all major axial categories represented. However, we conclude based on adult expression patterns that planarians have a derived body plan and their asexual lifestyle may have allowed for large changes in HOX expression from the last common ancestor between arthropods, flatworms, and vertebrates. Using our in situ method and axial zone RNAseq data, it should be possible to further understand the pathways that pattern the anterior-posterior axis of adult planarians.
2016-03-08 | GSE78937 | GEO
Project description:During adult homeostasis and regeneration, the freshwater planarian must accomplish a constant balance between cell proliferation and cell death, while also maintaining proper tissue and organ size and patterning. Yet how these ordered processes are precisely modulated, remains relatively unknown. Here we show that planarians use the downstream effector of the Hippo signalling cascade, yorkie (yki; YAP in vertebrates) to control a diverse set of pleiotropic processes in organ homeostasis, stem cell regulation, regeneration, and axial patterning. We show that yki functions to maintain the homeostasis of the planarian excretory (protonephridial) system and to limit stem cell proliferation, while not affecting the differentiation process or cell death. Finally, we show that yki synergizes with WNT/β-catenin signalling to repress head determination by limiting the expression domains of posterior WNT genes and the WNT-inhibitor notum. Together, our data show that yki is a key factor in planarians that integrates stem cell proliferation control, organ homeostasis, and the spatial patterning of tissues.
2015-10-03 | GSE73700 | GEO
Project description:RNA sequencing identified new anterior-pole enriched genes encoding transcription factors, a secreted protein, and a transmembrane protein, including NR4A, a nuclear receptor gene that is important in patterning the planarian head and tail.
2019-05-25 | GSE121045 | GEO
Project description:The head-regeneration transcriptome of the planarian Schmidtea mediterranea
2011-07-15 | E-MTAB-607 | biostudies-arrayexpress
Project description:Lipid metabolism is recognized as a key process for stem cell maintenance and differentiation but genetic factors that instruct stem cell function by influencing lipid metabolism remain to be delineated. Here we identify Tnfaip2 as an inhibitor of reprogramming of mouse fibroblasts into induced pluripotent stem cells. Tnfaip2 knockout embryonic stem cells (ESCs) exhibit differentiation failure and knockdown of the planarian orthologue, Smed-exoc3, abrogates in vivo differentiation of somatic stem cells, tissue homeostasis, and regeneration. Tnfaip2 deficient ESCs fail to induce synthesis of cellular triacylglycerol (TAG) and lipid droplets (LD) coinciding with reduced expression of Vimentin (Vim) – a known inducer of LD formation. Knockdown of Vim and Tnfaip2 act epistatically in enhancing cellular reprogramming of mouse fibroblasts. Similarly, planarians devoid of Smed-exoc3 displayed acute loss of TAGs. Supplementation of palmitic acid (PA) and palmitoyl-L-carnitine (a mitochondrial carrier of PA) restores the differentiation capacity of Tnfaip2 deficient ESCs as well as stem cell differentiation and organ maintenance in Smed-exoc3-depleted planarians. Together, these results identify a novel pathway, which is essential for stem cell differentiation and organ maintenance by instructing lipid metabolism.
2020-11-16 | GSE134300 | GEO
Project description:Yorkie is required to restrict the injury responses in planarians
| PRJNA382883 | ENA
Project description:Throughout Metazoa, developmental processes are controlled by a surprisingly limited number of conserved signaling pathways. Precisely how these signaling cassettes were assembled in early animal evolution remains poorly understood, as do the molecular transitions that potentiated the acquisition of their myriad developmental functions. Here we analyze the molecular evolution of the proto-oncogene YAP/Yorkie, a key effector of the Hippo signaling pathway that controls organ size in both Drosophila and mammals. Based on heterologous functional analysis of evolutionarily distant Yap/Yorkie orthologs, we demonstrate that a structurally distinct interaction interface between Yap/Yorkie and its partner TEAD/Scalloped became fixed in the eumetazoan common ancestor. We then combine transcriptional profiling of tissues expressing phylogenetically diverse forms of Yap/Yorkie with ChIP-seq validation in order to identify a common downstream gene expression program underlying the control of tissue growth in Drosophila. Intriguingly, a subset of the newly-identified Yorkie target genes are also induced by Yap in mammalian tissues, thus revealing a conserved Yap-dependent gene expression signature likely to mediate organ size control throughout bilaterian animals. Combined, these experiments provide new mechanistic insights while revealing the ancient evolutionary history of Hippo signaling. We sought to define the downstream target genes of selected Yap variants by performing RNA sequencing analysis (RNA-seq) on total RNA isolated from GMR-Gal4>Yap eye discs. Transcriptional profiles were generated in triplicate from eye imaginal disks with either endogenous Yki, or GMR-Gal4 over-expressed Yki, Trichoplax Yap, Monosiga Yap, or Monisiga Yap+TEAD domain, using deep sequencing via Illumina Hi Seq.
2014-03-01 | E-GEOD-54600 | biostudies-arrayexpress
Project description:Throughout Metazoa, developmental processes are controlled by a surprisingly limited number of conserved signaling pathways. Precisely how these signaling cassettes were assembled in early animal evolution remains poorly understood, as do the molecular transitions that potentiated the acquisition of their myriad developmental functions. Here we analyze the molecular evolution of the proto-oncogene YAP/Yorkie, a key effector of the Hippo signaling pathway that controls organ size in both Drosophila and mammals. Based on heterologous functional analysis of evolutionarily distant Yap/Yorkie orthologs, we demonstrate that a structurally distinct interaction interface between Yap/Yorkie and its partner TEAD/Scalloped became fixed in the eumetazoan common ancestor. We then combine transcriptional profiling of tissues expressing phylogenetically diverse forms of Yap/Yorkie with ChIP-seq validation in order to identify a common downstream gene expression program underlying the control of tissue growth in Drosophila. Intriguingly, a subset of the newly-identified Yorkie target genes are also induced by Yap in mammalian tissues, thus revealing a conserved Yap-dependent gene expression signature likely to mediate organ size control throughout bilaterian animals. Combined, these experiments provide new mechanistic insights while revealing the ancient evolutionary history of Hippo signaling. We sought to determine Yki and Sd target genes in Drosophila by immunoprecipitation of Yki, sd and RNA polymerase II. Chromatin immunoprecipitation of Yki, sd, and RNA polymerase II from eye disks was performed.
2014-03-01 | E-GEOD-54601 | 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