1
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Chereddy SCRR, Makino T. Conserved Genes in Highly Regenerative Metazoans Are Associated with Planarian Regeneration. Genome Biol Evol 2024; 16:evae082. [PMID: 38652806 PMCID: PMC11077316 DOI: 10.1093/gbe/evae082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/10/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
Metazoan species depict a wide spectrum of regeneration ability which calls into question the evolutionary origins of the underlying processes. Since species with high regeneration ability are widely distributed throughout metazoans, there is a possibility that the metazoan ancestor had an underlying common molecular mechanism. Early metazoans like sponges possess high regenerative ability, but, due to the large differences they have with Cnidaria and Bilateria regarding symmetry and neuronal systems, it can be inferred that this regenerative ability is different. We hypothesized that the last common ancestor of Cnidaria and Bilateria possessed remarkable regenerative ability which was lost during evolution. We separated Cnidaria and Bilateria into three classes possessing whole-body regenerating, high regenerative ability, and low regenerative ability. Using a multiway BLAST and gene phylogeny approach, we identified genes conserved in whole-body regenerating species and lost in low regenerative ability species and labeled them Cnidaria and Bilaterian regeneration genes. Through transcription factor analysis, we identified that Cnidaria and Bilaterian regeneration genes were associated with an overabundance of homeodomain regulatory elements. RNA interference of Cnidaria and Bilaterian regeneration genes resulted in loss of regeneration phenotype for HRJDa, HRJDb, DUF21, DISP3, and ARMR genes. We observed that DUF21 knockdown was highly lethal in the early stages of regeneration indicating a potential role in wound response. Also, HRJDa, HRJDb, DISP3, and ARMR knockdown showed loss of regeneration phenotype after second amputation. The results strongly correlate with their respective RNA-seq profiles. We propose that Cnidaria and Bilaterian regeneration genes play a major role in regeneration across highly regenerative Cnidaria and Bilateria.
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Affiliation(s)
| | - Takashi Makino
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Japan
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2
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Allikka Parambil S, Li D, Zelko M, Poulet A, van Wolfswinkel J. piRNA generation is associated with the pioneer round of translation in stem cells. Nucleic Acids Res 2024; 52:2590-2608. [PMID: 38142432 PMCID: PMC10954484 DOI: 10.1093/nar/gkad1212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/26/2023] Open
Abstract
Much insight has been gained on how stem cells maintain genomic integrity, but less attention has been paid to how they maintain their transcriptome. Here, we report that the PIWI protein SMEDWI-1 plays a role in the filtering of dysfunctional transcripts from the transcriptome of planarian stem cells. SMEDWI-1 accomplishes this through association with the ribosomes during the pioneer round of translation, and processing of poorly translated transcripts into piRNAs. This results in the removal of such transcripts from the cytoplasmic pool and at the same time creates a dynamic pool of small RNAs for post-transcriptional surveillance through the piRNA pathway. Loss of SMEDWI-1 results in elevated levels of several non-coding transcripts, including rRNAs, snRNAs and pseudogene mRNAs, while reducing levels of several coding transcripts. In the absence of SMEDWI-1, stem cell colonies are delayed in their expansion and a higher fraction of descendants exit the stem cell state, indicating that this transcriptomic sanitation mediated by SMEDWI-1 is essential to maintain stem cell health. This study presents a new model for the function of PIWI proteins in stem cell maintenance, that complements their role in transposon repression, and proposes a new biogenesis pathway for piRNAs in stem cells.
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Affiliation(s)
- Sudheesh Allikka Parambil
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Center for RNA science and medicine, Yale School of Medicine, New Haven. CT 06511, USA
| | - Danyan Li
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Center for RNA science and medicine, Yale School of Medicine, New Haven. CT 06511, USA
| | - Michael Zelko
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Center for RNA science and medicine, Yale School of Medicine, New Haven. CT 06511, USA
| | - Axel Poulet
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Center for RNA science and medicine, Yale School of Medicine, New Haven. CT 06511, USA
| | - Josien C van Wolfswinkel
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Center for RNA science and medicine, Yale School of Medicine, New Haven. CT 06511, USA
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3
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Kostyuchenko RP, Nikanorova DD, Amosov AV. Germ Line/Multipotency Genes Show Differential Expression during Embryonic Development of the Annelid Enchytraeus coronatus. BIOLOGY 2023; 12:1508. [PMID: 38132334 PMCID: PMC10740902 DOI: 10.3390/biology12121508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023]
Abstract
Germ line development and the origin of the primordial germ cells (PGCs) are very variable and may occur across a range of developmental stages and in several developmental contexts. In establishing and maintaining germ line, a conserved set of genes is involved. On the other hand, these genes are expressed in multipotent/pluripotent cells that may give rise to both somatic and germline cells. To begin elucidating mechanisms by which the germ line is specified in Enchytraeus coronatus embryos, we identified twenty germline/multipotency genes, homologs of Vasa, PL10, Piwi, Nanos, Myc, Pumilio, Tudor, Boule, and Bruno, using transcriptome analysis and gene cloning, and characterized their expression by whole-mount in situ hybridization. To answer the question of the possible origin of PGCs in this annelid, we carried out an additional description of the early embryogenesis. Our results suggest that PGCs derive from small cells originating at the first two divisions of the mesoteloblasts. PGCs form two cell clusters, undergo limited proliferation, and migrate to the developing gonadal segments. In embryos and juvenile E. coronatus, homologs of the germline/multipotency genes are differentially expressed in both germline and somatic tissue including the presumptive germ cell precursors, posterior growth zone, developing foregut, and nervous system.
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Affiliation(s)
- Roman P. Kostyuchenko
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia; (D.D.N.); (A.V.A.)
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4
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Tajer B, Savage AM, Whited JL. The salamander blastema within the broader context of metazoan regeneration. Front Cell Dev Biol 2023; 11:1206157. [PMID: 37635872 PMCID: PMC10450636 DOI: 10.3389/fcell.2023.1206157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/26/2023] [Indexed: 08/29/2023] Open
Abstract
Throughout the animal kingdom regenerative ability varies greatly from species to species, and even tissue to tissue within the same organism. The sheer diversity of structures and mechanisms renders a thorough comparison of molecular processes truly daunting. Are "blastemas" found in organisms as distantly related as planarians and axolotls derived from the same ancestral process, or did they arise convergently and independently? Is a mouse digit tip blastema orthologous to a salamander limb blastema? In other fields, the thorough characterization of a reference model has greatly facilitated these comparisons. For example, the amphibian Spemann-Mangold organizer has served as an amazingly useful comparative template within the field of developmental biology, allowing researchers to draw analogies between distantly related species, and developmental processes which are superficially quite different. The salamander limb blastema may serve as the best starting point for a comparative analysis of regeneration, as it has been characterized by over 200 years of research and is supported by a growing arsenal of molecular tools. The anatomical and evolutionary closeness of the salamander and human limb also add value from a translational and therapeutic standpoint. Tracing the evolutionary origins of the salamander blastema, and its relatedness to other regenerative processes throughout the animal kingdom, will both enhance our basic biological understanding of regeneration and inform our selection of regenerative model systems.
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Affiliation(s)
| | | | - Jessica L. Whited
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, United States
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5
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Kostyuchenko RP, Smirnova NP. Vasa, Piwi, and Pl10 Expression during Sexual Maturation and Asexual Reproduction in the Annelid Pristina longiseta. J Dev Biol 2023; 11:34. [PMID: 37606490 PMCID: PMC10443295 DOI: 10.3390/jdb11030034] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/23/2023] Open
Abstract
Naidids are tiny, transparent freshwater oligochaetes, which are well known for their ability to propagate asexually. Despite the fact that sexually mature individuals and cocoons with embryos are sometimes found in nature, in long-period laboratory cultures, worms reproduce agametically only. In this paper, we showed, for the first time, the expression of Vasa, Piwi, and Pl10 homologs in mature Pristina longiseta worms with well-developed reproductive system structures and germ cells. Although the animals have been propagated asexually by paratomic fission for over 20 years in our lab, some individuals become sexualized under standard conditions for our laboratory culture and demonstrate various stages of maturation. The fully matured animals developed a complete set of sexual apparatus including spermatheca, atrium, seminal vesicles, and ovisac. They also had a clitellum and were able to form cocoons. The cues for the initiation of sexual maturation are still unknown for P. longiseta; nevertheless, our data suggest that the laboratory strain of P. longiseta maintains the ability to become fully sexually mature and to establish germline products even after a long period of agametic reproduction. On the other hand, many of the sexualized worms formed a fission zone and continued to reproduce asexually. Thus, in this species, the processes of asexual reproduction and sexual maturation do not preclude each other, and Vasa, Piwi, and Pl10 homologs are expressed in both somatic and germline tissue including the posterior growth zone, fission zone, nervous system, germline cells, and gametes.
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Affiliation(s)
- Roman P. Kostyuchenko
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia;
| | - Natalia P. Smirnova
- Department of Embryology, St. Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia;
- Unit for Cell Signaling, Department of Immunology and Transfusion Medicine, Oslo University Hospital, 0317 Oslo, Norway
- Hybrid Technology Hub-Centre for Organ on a Chip-Technology, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
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6
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Wang X, Ramat A, Simonelig M, Liu MF. Emerging roles and functional mechanisms of PIWI-interacting RNAs. Nat Rev Mol Cell Biol 2023; 24:123-141. [PMID: 36104626 DOI: 10.1038/s41580-022-00528-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 61.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2022] [Indexed: 02/02/2023]
Abstract
PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs that associate with proteins of the PIWI clade of the Argonaute family. First identified in animal germ line cells, piRNAs have essential roles in germ line development. The first function of PIWI-piRNA complexes to be described was the silencing of transposable elements, which is crucial for maintaining the integrity of the germ line genome. Later studies provided new insights into the functions of PIWI-piRNA complexes by demonstrating that they regulate protein-coding genes. Recent studies of piRNA biology, including in new model organisms such as golden hamsters, have deepened our understanding of both piRNA biogenesis and piRNA function. In this Review, we discuss the most recent advances in our understanding of piRNA biogenesis, the molecular mechanisms of piRNA function and the emerging roles of piRNAs in germ line development mainly in flies and mice, and in infertility, cancer and neurological diseases in humans.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China.,Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Anne Ramat
- Institute of Human Genetics, University of Montpellier, CNRS, Montpellier, France
| | - Martine Simonelig
- Institute of Human Genetics, University of Montpellier, CNRS, Montpellier, France.
| | - Mo-Fang Liu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China. .,Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China. .,School of Life Science and Technology, Shanghai Tech University, Shanghai, China.
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7
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Kim IV, Demtröder T, Kuhn CD. Isolation and Library Preparation of Planarian piRNAs. Methods Mol Biol 2023; 2680:29-54. [PMID: 37428369 DOI: 10.1007/978-1-0716-3275-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
In planarian flatworms, piRNAs and SMEDWI (Schmidtea mediterranea PIWI) proteins are both essential for the animals' impressive regenerative ability and for their survival. A knockdown of SMEDWI proteins disrupts the specification of the planarian germline and impairs stem cell differentiation, resulting in lethal phenotypes. As the molecular targets of PIWI proteins and thus their biological function are determined by PIWI-bound small RNAs, termed piRNAs (for PIWI-interacting RNAs), it is imperative to study the wealth of PIWI-bound piRNAs using next-generation sequencing-based techniques. Prior to sequencing, piRNAs bound to individual SMEDWI proteins must be isolated. To that end, we established an immunoprecipitation protocol that can be applied to all planarian SMEDWI proteins. Co-immunoprecipitated piRNAs are visualized by using qualitative radioactive 5'-end labeling, which detects even trace amounts of small RNAs. Next, isolated piRNAs are subjected to a library preparation protocol that has been optimized for the efficient capture of piRNAs, whose 3'-ends carry a 2'-O-methyl modification. Successfully prepared piRNA libraries are subjected to Illumina-based next-generation sequencing. Obtained data are analyzed as presented in the accompanying manuscript.
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Affiliation(s)
- Iana V Kim
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Tim Demtröder
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Claus-D Kuhn
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany.
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8
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Pittroff A, Kim IV, Demtröder T, Kuhn CD. Genome-Wide Analysis of Planarian piRNAs. Methods Mol Biol 2023; 2680:55-65. [PMID: 37428370 DOI: 10.1007/978-1-0716-3275-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
In planarian flatworms, the piRNA pathway is operated by three PIWI proteins, termed SMEDWI-1, SMEDWI-2, and SMEDWI-3 (SMEDWI = Schmidtea mediterranea PIWI). The interplay between these three PIWI proteins and their associated small noncoding RNAs, termed piRNAs, fuels the outstanding regenerative abilities of planarians, enables tissue homeostasis, and, ultimately, ensures animal survival. As the molecular targets of PIWI proteins are determined by the sequences of their co-bound piRNAs, it is imperative to identify these sequences by next-generation sequencing applications. Following sequencing, the genomic targets and the regulatory potential of the isolated piRNA populations need to be uncovered. To that end, here we present a bioinformatics analysis pipeline for processing and systematic characterization of planarian piRNAs. The pipeline includes steps for the removal of PCR duplicates based on unique molecular identifier (UMI) sequences, and it accounts for piRNA multimapping to different loci in the genome. Importantly, our protocol also includes a fully automated pipeline that is freely available at GitHub. Together with the piRNA isolation and library preparation protocol (see accompanying chapter), the presented computational pipeline enables researchers to explore the functional role of the piRNA pathway in flatworm biology.
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Affiliation(s)
| | - Iana V Kim
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Tim Demtröder
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Claus-D Kuhn
- RNA Biochemistry, University of Bayreuth, Bayreuth, Germany.
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9
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Angileri KM, Bagia NA, Feschotte C. Transposon control as a checkpoint for tissue regeneration. Development 2022; 149:dev191957. [PMID: 36440631 PMCID: PMC10655923 DOI: 10.1242/dev.191957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 10/03/2022] [Indexed: 11/29/2022]
Abstract
Tissue regeneration requires precise temporal control of cellular processes such as inflammatory signaling, chromatin remodeling and proliferation. The combination of these processes forms a unique microenvironment permissive to the expression, and potential mobilization of, transposable elements (TEs). Here, we develop the hypothesis that TE activation creates a barrier to tissue repair that must be overcome to achieve successful regeneration. We discuss how uncontrolled TE activity may impede tissue restoration and review mechanisms by which TE activity may be controlled during regeneration. We posit that the diversification and co-evolution of TEs and host control mechanisms may contribute to the wide variation in regenerative competency across tissues and species.
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Affiliation(s)
- Krista M. Angileri
- Department of Molecular Biology and Genetics, Cornell University, 526 Campus Rd, Ithaca, NY 14850, USA
| | - Nornubari A. Bagia
- Department of Molecular Biology and Genetics, Cornell University, 526 Campus Rd, Ithaca, NY 14850, USA
| | - Cedric Feschotte
- Department of Molecular Biology and Genetics, Cornell University, 526 Campus Rd, Ithaca, NY 14850, USA
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10
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Galton R, Fejes-Toth K, Bronner ME. Co-option of the piRNA pathway to regulate neural crest specification. SCIENCE ADVANCES 2022; 8:eabn1441. [PMID: 35947657 PMCID: PMC9365273 DOI: 10.1126/sciadv.abn1441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/24/2022] [Indexed: 05/26/2023]
Abstract
Across Metazoa, Piwi proteins play a critical role in protecting the germline genome through piRNA-mediated repression of transposable elements. In vertebrates, activity of Piwi proteins and the piRNA pathway was thought to be gonad specific. Our results reveal the expression of Piwil1 in a vertebrate somatic cell type, the neural crest. Piwil1 is expressed at low levels throughout the chicken neural tube, peaking in neural crest cells just before the specification event that enables epithelial-to-mesenchymal transition (EMT) and migration into the periphery. Loss of Piwil1 impedes neural crest specification and emigration. Small RNA sequencing reveals somatic piRNAs with sequence signatures of an active ping-pong loop. RNA-seq and functional experiments identify the transposon-derived gene ERNI as Piwil1's target in the neural crest. ERNI, in turn, suppresses Sox2 to precisely control the timing of neural crest specification and EMT. Our data provide mechanistic insight into a novel function of the piRNA pathway as a regulator of somatic development in a vertebrate species.
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Affiliation(s)
| | - Katalin Fejes-Toth
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Marianne E. Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
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11
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Ebner JN, Wyss MK, Ritz D, von Fumetti S. Effects of thermal acclimation on the proteome of the planarian Crenobia alpina from an alpine freshwater spring. J Exp Biol 2022; 225:276068. [PMID: 35875852 PMCID: PMC9440759 DOI: 10.1242/jeb.244218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/18/2022] [Indexed: 11/25/2022]
Abstract
Species' acclimation capacity and their ability to maintain molecular homeostasis outside ideal temperature ranges will partly predict their success following climate change-induced thermal regime shifts. Theory predicts that ectothermic organisms from thermally stable environments have muted plasticity, and that these species may be particularly vulnerable to temperature increases. Whether such species retained or lost acclimation capacity remains largely unknown. We studied proteome changes in the planarian Crenobia alpina, a prominent member of cold-stable alpine habitats that is considered to be a cold-adapted stenotherm. We found that the species' critical thermal maximum (CTmax) is above its experienced habitat temperatures and that different populations exhibit differential CTmax acclimation capacity, whereby an alpine population showed reduced plasticity. In a separate experiment, we acclimated C. alpina individuals from the alpine population to 8, 11, 14 or 17°C over the course of 168 h and compared their comprehensively annotated proteomes. Network analyses of 3399 proteins and protein set enrichment showed that while the species' proteome is overall stable across these temperatures, protein sets functioning in oxidative stress response, mitochondria, protein synthesis and turnover are lower in abundance following warm acclimation. Proteins associated with an unfolded protein response, ciliogenesis, tissue damage repair, development and the innate immune system were higher in abundance following warm acclimation. Our findings suggest that this species has not suffered DNA decay (e.g. loss of heat-shock proteins) during evolution in a cold-stable environment and has retained plasticity in response to elevated temperatures, challenging the notion that stable environments necessarily result in muted plasticity. Summary: The proteome of an alpine Crenobia alpina population shows plasticity in response to acclimation to warmer temperatures.
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Affiliation(s)
- Joshua Niklas Ebner
- 1 Spring Ecology Research Group, Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Mirjam Kathrin Wyss
- 1 Spring Ecology Research Group, Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Danilo Ritz
- 2 Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Stefanie von Fumetti
- 1 Spring Ecology Research Group, Department of Environmental Sciences, University of Basel, Basel, Switzerland
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12
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A Krüppel-like factor is required for development and regeneration of germline and yolk cells from somatic stem cells in planarians. PLoS Biol 2022; 20:e3001472. [PMID: 35839223 PMCID: PMC9286257 DOI: 10.1371/journal.pbio.3001472] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 06/13/2022] [Indexed: 12/02/2022] Open
Abstract
Sexually reproducing animals segregate their germline from their soma. In addition to gamete-producing gonads, planarian and parasitic flatworm reproduction relies on yolk cell–generating accessory reproductive organs (vitellaria) supporting development of yolkless oocytes. Despite the importance of vitellaria for flatworm reproduction (and parasite transmission), little is known about this unique evolutionary innovation. Here, we examine reproductive system development in the planarian Schmidtea mediterranea, in which pluripotent stem cells generate both somatic and germ cell lineages. We show that a homolog of the pluripotency factor Klf4 is expressed in primordial germ cells (PGCs), presumptive germline stem cells (GSCs), and yolk cell progenitors. Knockdown of this klf4-like (klf4l) gene results in animals that fail to specify or maintain germ cells; surprisingly, they also fail to maintain yolk cells. We find that yolk cells display germ cell–like attributes and that vitellaria are structurally analogous to gonads. In addition to identifying a new proliferative cell population in planarians (yolk cell progenitors) and defining its niche, our work provides evidence supporting the hypothesis that flatworm germ cells and yolk cells share a common evolutionary origin.
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13
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Davidian D, LeGro M, Barghouth PG, Rojas S, Ziman B, Maciel EI, Ardell D, Escobar AL, Oviedo NJ. Restoration of DNA integrity and cell cycle by electric stimulation in planarian tissues damaged by ionizing radiation. J Cell Sci 2022; 135:274829. [PMID: 35322853 PMCID: PMC9264365 DOI: 10.1242/jcs.259304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 03/05/2022] [Indexed: 10/18/2022] Open
Abstract
Exposure to high levels of ionizing γ-radiation leads to irreversible DNA damage and cell death. Here, we establish that exogenous application of electric stimulation enables cellular plasticity to reestablish stem cell activity in tissues damaged by ionizing radiation. We show that sub-threshold direct current stimulation (DCS) rapidly restores pluripotent stem cell populations previously eliminated by lethally γ-irradiated tissues of the planarian flatworm Schmidtea mediterranea. Our findings reveal that DCS enhances DNA repair, transcriptional activity, and cell cycle entry in post-mitotic cells. These responses involve rapid increases in cytosolic [Ca2+] through the activation of L-type Cav channels and intracellular Ca2+ stores leading to the activation of immediate early genes and ectopic expression of stem cell markers in postmitotic cells. Overall, we show the potential of electric current stimulation to reverse the damaging effects of high dose γ-radiation in adult tissues. Furthermore, our results provide mechanistic insights describing how electric stimulation effectively translates into molecular responses capable of regulating fundamental cellular functions without the need for genetic or pharmacological intervention.
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Affiliation(s)
- Devon Davidian
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Melanie LeGro
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Paul G Barghouth
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Salvador Rojas
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Benjamin Ziman
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - Eli Isael Maciel
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Quantitative and Systems Biology Graduate Program, University of California, Merced, USA
| | - David Ardell
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
| | - Ariel L Escobar
- Department of Bioengineering, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
| | - Néstor J Oviedo
- Department of Molecular & Cell Biology, University of California, Merced, USA.,Health Sciences Research Institute, University of California, Merced, USA
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14
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Razmi K, Patil JG. Primordial Germ Cell Development in the Poeciliid, Gambusia holbrooki, Reveals Shared Features Between Lecithotrophs and Matrotrophs. Front Cell Dev Biol 2022; 10:793498. [PMID: 35300414 PMCID: PMC8920993 DOI: 10.3389/fcell.2022.793498] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/03/2022] [Indexed: 12/02/2022] Open
Abstract
Metazoans exhibit two modes of primordial germ cell (PGC) specification that are interspersed across taxa. However, the evolutionary link between the two modes and the reproductive strategies of lecithotrophy and matrotrophy is poorly understood. As a first step to understand this, the spatio-temporal expression of teleostean germ plasm markers was investigated in Gambusia holbrooki, a poecilid with shared lecitho- and matrotrophy. A group of germ plasm components was detected in the ovum suggesting maternal inheritance mode of PGC specification. However, the strictly zygotic activation of dnd-β and nanos1 occurred relatively early, reminiscent of models with induction mode (e.g., mice). The PGC clustering, migration and colonisation patterns of G. holbrooki resembled those of zebrafish, medaka and mice at blastula, gastrula and somitogenesis, respectively—recapitulating features of advancing evolutionary nodes with progressive developmental stages. Moreover, the expression domains of PGC markers in G. holbrooki were either specific to teleost (vasa expression in developing PGCs), murine models (dnd spliced variants) or shared between the two taxa (germline and somatic expression of piwi and nanos1). Collectively, the results suggest that the reproductive developmental adaptations may reflect a transition from lecithotrophy to matrotrophy.
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Affiliation(s)
- Komeil Razmi
- Laboratory of Molecular Biology, Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS, Australia
| | - Jawahar G Patil
- Laboratory of Molecular Biology, Fisheries and Aquaculture Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, TAS, Australia
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15
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Lee H, Hikasa K, Umesono Y, Hayashi T, Agata K, Shibata N. Loss of plac8 expression rapidly leads pluripotent stem cells to enter active state during planarian regeneration. Development 2022; 149:274215. [DOI: 10.1242/dev.199449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 12/20/2021] [Indexed: 01/18/2023]
Abstract
ABSTRACT
The regenerative ability of planarians relies on their adult pluripotent stem cell population. Although all stem cells express a piwi homolog, recently it has become possible to classify the piwi+ stem cell population into specialized subpopulations according to the expression of genes related to differentiation. However, piwi+ stem cells behave practically as a homogeneous population after amputation, during which stem cells show accelerated proliferation, named ‘induced hyperproliferation’. Here, we show that plac8-A was expressed in almost all of the stem cells, and that a decrease of the plac8-A expression level led to induced hyperproliferation uniformly in a broad stem cell subpopulation after amputation. This reduction of plac8-A expression was caused by activated JNK signaling after amputation. Pharmacological inhibition of JNK signaling caused failure to induce hyperproliferation and resulted in regenerative defects. Such defects were abrogated by simultaneous knockdown of plac8-A expression. Thus, JNK-dependent suppression of plac8-A expression is indispensable for stem cell dynamics involved in regeneration. These findings suggest that plac8-A acts as a molecular switch of piwi+ stem cells for entry into the regenerative state after amputation.
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Affiliation(s)
- Hayoung Lee
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kanon Hikasa
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College 624-1, Numa, Tsuyama-City, Okayama 708-8509, Japan
| | - Yoshihiko Umesono
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tetsutaro Hayashi
- Laboratory for Phyloinformatics, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
- Laboratory of Regeneration Biology, National Institute for Basic Biology, Nishigoaka 38, Myodaiji, Okazaki, 444-8585 Aichi, Japan
| | - Norito Shibata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College 624-1, Numa, Tsuyama-City, Okayama 708-8509, Japan
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16
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Rinkevich B, Ballarin L, Martinez P, Somorjai I, Ben-Hamo O, Borisenko I, Berezikov E, Ereskovsky A, Gazave E, Khnykin D, Manni L, Petukhova O, Rosner A, Röttinger E, Spagnuolo A, Sugni M, Tiozzo S, Hobmayer B. A pan-metazoan concept for adult stem cells: the wobbling Penrose landscape. Biol Rev Camb Philos Soc 2021; 97:299-325. [PMID: 34617397 PMCID: PMC9292022 DOI: 10.1111/brv.12801] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 12/17/2022]
Abstract
Adult stem cells (ASCs) in vertebrates and model invertebrates (e.g. Drosophila melanogaster) are typically long‐lived, lineage‐restricted, clonogenic and quiescent cells with somatic descendants and tissue/organ‐restricted activities. Such ASCs are mostly rare, morphologically undifferentiated, and undergo asymmetric cell division. Characterized by ‘stemness’ gene expression, they can regulate tissue/organ homeostasis, repair and regeneration. By contrast, analysis of other animal phyla shows that ASCs emerge at different life stages, present both differentiated and undifferentiated phenotypes, and may possess amoeboid movement. Usually pluri/totipotent, they may express germ‐cell markers, but often lack germ‐line sequestering, and typically do not reside in discrete niches. ASCs may constitute up to 40% of animal cells, and participate in a range of biological phenomena, from whole‐body regeneration, dormancy, and agametic asexual reproduction, to indeterminate growth. They are considered legitimate units of selection. Conceptualizing this divergence, we present an alternative stemness metaphor to the Waddington landscape: the ‘wobbling Penrose’ landscape. Here, totipotent ASCs adopt ascending/descending courses of an ‘Escherian stairwell’, in a lifelong totipotency pathway. ASCs may also travel along lower stemness echelons to reach fully differentiated states. However, from any starting state, cells can change their stemness status, underscoring their dynamic cellular potencies. Thus, vertebrate ASCs may reflect just one metazoan ASC archetype.
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Affiliation(s)
- Baruch Rinkevich
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Loriano Ballarin
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, Padova, 35121, Italy
| | - Pedro Martinez
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Av. Diagonal 643, Barcelona, 08028, Spain.,Institut Català de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain
| | - Ildiko Somorjai
- School of Biology, University of St Andrews, St Andrews, Fife, KY16 9ST, Scotland, UK
| | - Oshrat Ben-Hamo
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Ilya Borisenko
- Department of Embryology, Faculty of Biology, Saint-Petersburg State University, University Embankment, 7/9, Saint-Petersburg, 199034, Russia
| | - Eugene Berezikov
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Alexander Ereskovsky
- Department of Embryology, Faculty of Biology, Saint-Petersburg State University, University Embankment, 7/9, Saint-Petersburg, 199034, Russia.,Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE), Aix Marseille University, CNRS, IRD, Avignon University, Jardin du Pharo, 58 Boulevard Charles Livon, Marseille, 13007, France.,Koltzov Institute of Developmental Biology of Russian Academy of Sciences, Ulitsa Vavilova, 26, Moscow, 119334, Russia
| | - Eve Gazave
- Université de Paris, CNRS, Institut Jacques Monod, Paris, F-75006, France
| | - Denis Khnykin
- Department of Pathology, Oslo University Hospital, Bygg 19, Gaustad Sykehus, Sognsvannsveien 21, Oslo, 0188, Norway
| | - Lucia Manni
- Department of Biology, University of Padova, Via Ugo Bassi 58/B, Padova, 35121, Italy
| | - Olga Petukhova
- Collection of Vertebrate Cell Cultures, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg, 194064, Russia
| | - Amalia Rosner
- Israel Oceanographic & Limnological Research, National Institute of Oceanography, POB 9753, Tel Shikmona, Haifa, 3109701, Israel
| | - Eric Röttinger
- Université Côte d'Azur, CNRS, INSERM, Institute for Research on Cancer and Aging, Nice (IRCAN), Nice, 06107, France.,Université Côte d'Azur, Federative Research Institute - Marine Resources (IFR MARRES), 28 Avenue de Valrose, Nice, 06103, France
| | - Antonietta Spagnuolo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, 80121, Italy
| | - Michela Sugni
- Department of Environmental Science and Policy (ESP), Università degli Studi di Milano, Via Celoria 26, Milan, 20133, Italy
| | - Stefano Tiozzo
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06234 Villefranche-sur-Mer, Villefranche sur Mer, Cedex, France
| | - Bert Hobmayer
- Institute of Zoology and Center for Molecular Biosciences, University of Innsbruck, Technikerstr, Innsbruck, 256020, Austria
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17
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Li D, Taylor DH, van Wolfswinkel JC. PIWI-mediated control of tissue-specific transposons is essential for somatic cell differentiation. Cell Rep 2021; 37:109776. [PMID: 34610311 PMCID: PMC8532177 DOI: 10.1016/j.celrep.2021.109776] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/27/2021] [Accepted: 09/07/2021] [Indexed: 12/24/2022] Open
Abstract
PIWI proteins are known as mediators of transposon silencing in animal germlines but are also found in adult pluripotent stem cells of highly regenerative animals, where they are essential for regeneration. Study of the nuclear PIWI protein SMEDWI-2 in the planarian somatic stem cell system reveals an intricate interplay between transposons and cell differentiation in which a subset of transposons is inevitably activated during cell differentiation, and the PIWI protein is required to regain control. Absence of SMEDWI-2 leads to tissue-specific transposon derepression related to cell-type-specific chromatin remodeling events and in addition causes reduced accessibility of lineage-specific genes and defective cell differentiation, resulting in fatal tissue dysfunction. Finally, we show that additional PIWI proteins provide a stem-cell-specific second layer of protection in planarian neoblasts. These findings reveal a far-reaching role of PIWI proteins and PIWI-interacting RNAs (piRNAs) in stem cell biology and cell differentiation.
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Affiliation(s)
- Danyan Li
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - David H Taylor
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Josien C van Wolfswinkel
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.
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18
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Benham-Pyle BW, Brewster CE, Kent AM, Mann FG, Chen S, Scott AR, Box AC, Sánchez Alvarado A. Identification of rare, transient post-mitotic cell states that are induced by injury and required for whole-body regeneration in Schmidtea mediterranea. Nat Cell Biol 2021; 23:939-952. [PMID: 34475533 PMCID: PMC8855990 DOI: 10.1038/s41556-021-00734-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/14/2021] [Indexed: 01/02/2023]
Abstract
Regeneration requires the coordination of stem cells, their progeny and distant differentiated tissues. Here, we present a comprehensive atlas of whole-body regeneration in Schmidtea mediterranea and identify wound-induced cell states. An analysis of 299,998 single-cell transcriptomes captured from regeneration-competent and regeneration-incompetent fragments identified transient regeneration-activated cell states (TRACS) in the muscle, epidermis and intestine. TRACS were independent of stem cell division with distinct spatiotemporal distributions, and RNAi depletion of TRACS-enriched genes produced regeneration defects. Muscle expression of notum, follistatin, evi/wls, glypican-1 and junctophilin-1 was required for tissue polarity. Epidermal expression of agat-1/2/3, cyp3142a1, zfhx3 and atp1a1 was important for stem cell proliferation. Finally, expression of spectrinβ and atp12a in intestinal basal cells, and lrrk2, cathepsinB, myosin1e, polybromo-1 and talin-1 in intestinal enterocytes regulated stem cell proliferation and tissue remodelling, respectively. Our results identify cell types and molecules that are important for regeneration, indicating that regenerative ability can emerge from coordinated transcriptional plasticity across all three germ layers.
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Affiliation(s)
- Blair W Benham-Pyle
- Stowers Institute for Medical Research, Kansas City, MO, USA. .,Howard Hughes Institute for Medical Research, Kansas City, MO, USA.
| | | | - Aubrey M Kent
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Frederick G Mann
- Stowers Institute for Medical Research, Kansas City, MO, USA.,Howard Hughes Institute for Medical Research, Kansas City, MO, USA
| | - Shiyuan Chen
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Allison R Scott
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Andrew C Box
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO, USA. .,Howard Hughes Institute for Medical Research, Kansas City, MO, USA.
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19
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Huang X, Cheng P, Weng C, Xu Z, Zeng C, Xu Z, Chen X, Zhu C, Guang S, Feng X. A chromodomain protein mediates heterochromatin-directed piRNA expression. Proc Natl Acad Sci U S A 2021; 118:e2103723118. [PMID: 34187893 PMCID: PMC8271797 DOI: 10.1073/pnas.2103723118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PIWI-interacting RNAs (piRNAs) play significant roles in suppressing transposons, maintaining genome integrity, and defending against viral infections. How piRNA source loci are efficiently transcribed is poorly understood. Here, we show that in Caenorhabditis elegans, transcription of piRNA clusters depends on the chromatin microenvironment and a chromodomain-containing protein, UAD-2. piRNA clusters form distinct focus in germline nuclei. We conducted a forward genetic screening and identified UAD-2 that is required for piRNA focus formation. In the absence of histone 3 lysine 27 methylation or proper chromatin-remodeling status, UAD-2 is depleted from the piRNA focus. UAD-2 recruits the upstream sequence transcription complex (USTC), which binds the Ruby motif to piRNA promoters and promotes piRNA generation. Vice versa, the USTC complex is required for UAD-2 to associate with the piRNA focus. Thus, transcription of heterochromatic small RNA source loci relies on coordinated recruitment of both the readers of histone marks and the core transcriptional machinery to DNA.
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Affiliation(s)
- Xinya Huang
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Peng Cheng
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Chenchun Weng
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Zongxiu Xu
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Chenming Zeng
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Zheng Xu
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China
| | - Xiangyang Chen
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China;
| | - Chengming Zhu
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China;
| | - Shouhong Guang
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China;
- CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Hefei 230027, People's Republic of China
| | - Xuezhu Feng
- Ministry of Education Key Laboratory for Membraneless Organelles & Cellular Dynamics, Hefei National Laboratory for Physical Sciences at the Microscale, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, People's Republic of China;
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20
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Ballarin L, Karahan A, Salvetti A, Rossi L, Manni L, Rinkevich B, Rosner A, Voskoboynik A, Rosental B, Canesi L, Anselmi C, Pinsino A, Tohumcu BE, Jemec Kokalj A, Dolar A, Novak S, Sugni M, Corsi I, Drobne D. Stem Cells and Innate Immunity in Aquatic Invertebrates: Bridging Two Seemingly Disparate Disciplines for New Discoveries in Biology. Front Immunol 2021; 12:688106. [PMID: 34276677 PMCID: PMC8278520 DOI: 10.3389/fimmu.2021.688106] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022] Open
Abstract
The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to translational studies, further contributing to (eco)toxicology, biotechnology, and medicine as well as regulatory and ethical aspects. Stem cells originate immune cells through hematopoiesis, and the interplay between the two cell types is required in processes like regeneration. In addition, stem and immune cell anomalies directly affect the organism's functions, its ability to cope with environmental changes and, indirectly, its role in ecosystem services. However, stem cells and immune cells continue to be considered parts of two branches of biological research with few interconnections between them. This review aims to bridge these two seemingly disparate disciplines towards much more integrative and transformative approaches with examples deriving mainly from aquatic invertebrates. We discuss the current understanding of cross-disciplinary collaborative and emerging issues, raising novel hypotheses and comments. We also discuss the problems and perspectives of the two disciplines and how to integrate their conceptual frameworks to address basic equations in biology in a new, innovative way.
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Affiliation(s)
| | - Arzu Karahan
- Middle East Technical University, Institute of Marine Sciences, Erdemli, Mersin, Turkey
| | - Alessandra Salvetti
- Department of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Pisa, Italy
| | - Leonardo Rossi
- Department of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Pisa, Italy
| | - Lucia Manni
- Department of Biology, University of Padua, Padua, Italy
| | - Baruch Rinkevich
- Department of Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel
| | - Amalia Rosner
- Department of Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel
| | - Ayelet Voskoboynik
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Department of Biology, Chan Zuckerberg Biohub, San Francisco, CA, United States
| | - Benyamin Rosental
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Center for Regenerative Medicine and Stem Cells, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Laura Canesi
- Department of Earth Environment and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
| | - Chiara Anselmi
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
| | - Annalisa Pinsino
- Institute for Biomedical Research and Innovation, National Research Council, Palermo, Italy
| | - Begüm Ece Tohumcu
- Middle East Technical University, Institute of Marine Sciences, Erdemli, Mersin, Turkey
| | - Anita Jemec Kokalj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Andraž Dolar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Sara Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Michela Sugni
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Ilaria Corsi
- Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy
| | - Damjana Drobne
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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21
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Kimoto C, Nakagawa H, Hasegawa R, Nodono H, Matsumoto M. Co-localization of DrPiwi-1 and DrPiwi-2 in the oogonial cytoplasm is essential for oocyte differentiation in sexualized planarians. Cells Dev 2021; 167:203710. [PMID: 34171535 DOI: 10.1016/j.cdev.2021.203710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/02/2021] [Accepted: 06/11/2021] [Indexed: 11/18/2022]
Abstract
P-Element-induced wimpy testis (Piwi) subfamily proteins form complexes that bind to Piwi-interacting RNA. This interaction is crucial for stem cell regulation and formation, maintenance of germline stem cells, and gametogenesis in several metazoans. Planarians are effective models for studying stem cells. In the planarian Dugesia ryukyuensis, DrPiwi-1 is essential for the development of germ cells, but not somatic cells and sexual organs. DrPiwi-2 is indispensable for regeneration. In this study, we aimed to investigate the effects of Piwi on the differentiation of germ cells using monoclonal antibodies against DrPiwi-1 and DrPiwi-2. DrPiwi-1 and DrPiwi-2 co-localized more in immature germ cells than in mature germ cells in the ovary. DrPiwi-1 was found in the cytoplasm of early oogonia as undifferentiated germ cells, whereas DrPiwi-2 was found to localize not only in the nuclei but also in the cytoplasm of early oogonia. In descendant germ cells (oocytes), DrPiwi-2 was not present in the cytoplasm, but was strongly detected in the nucleolus. Moreover, we found that DrPiwi-1 forms a complex with DrPiwi-2. The cause of DrPiwi-1 depletion may be the severe reduction in the DrPiwi-2 level in the cytoplasm of oogonia. These results suggest that the formation of the DrPiwi-1 and DrPiwi-2 complex in the cytoplasm of oogonia is essential for oocyte differentiation. Our findings support the conclusion that DrPiwi-1 forms a complex with DrPiwi-2 in the cytoplasm of undifferentiated germ cells, and it signifies the start of gametogenesis. In contrast, in the testes, Drpiwi-1 was found in undifferentiated germ cells (spermatogonia), whereas DrPiwi-2 was found in descendant germ cells (spermatocytes). The process of germ cell differentiation from adult stem cells in planarians may be regulated in different ways in female and male germ lines by the Piwi family.
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Affiliation(s)
- Chiaki Kimoto
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Haruka Nakagawa
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Reiko Hasegawa
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Hanae Nodono
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Midori Matsumoto
- Department of Biological Sciences and Informatics, Keio University, 3-14-1, Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan.
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22
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Fontenla S, Rinaldi G, Tort JF. Lost and Found: Piwi and Argonaute Pathways in Flatworms. Front Cell Infect Microbiol 2021; 11:653695. [PMID: 34123869 PMCID: PMC8191739 DOI: 10.3389/fcimb.2021.653695] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Platyhelminthes comprise one of the major phyla of invertebrate animals, inhabiting a wide range of ecosystems, and one of the most successful in adapting to parasitic life. Small non-coding RNAs have been implicated in regulating complex developmental transitions in model parasitic species. Notably, parasitic flatworms have lost Piwi RNA pathways but gained a novel Argonaute gene. Herein, we analyzed, contrasted and compared the conservation of small RNA pathways among several free-living species (a paraphyletic group traditionally known as ‘turbellarians’) and parasitic species (organized in the monophyletic clade Neodermata) to disentangle possible adaptations during the transition to parasitism. Our findings showed that complete miRNA and RNAi pathways are present in all analyzed free-living flatworms. Remarkably, whilst all ‘turbellarians’ have Piwi proteins, these were lost in parasitic Neodermantans. Moreover, two clusters of Piwi class Argonaute genes are present in all ‘turbellarians’. Interestingly, we identified a divergent Piwi class Argonaute in free living flatworms exclusively, which we named ‘Fliwi’. In addition, other key proteins of the Piwi pathways were conserved in ‘turbellarians’, while none of them were detected in Neodermatans. Besides Piwi and the canonical Argonaute proteins, a flatworm-specific class of Argonautes (FL-Ago) was identified in the analyzed species confirming its ancestrallity to all Platyhelminthes. Remarkably, this clade was expanded in parasitic Neodermatans, but not in free-living species. These phyla-specific Argonautes showed lower sequence conservation compared to other Argonaute proteins, suggesting that they might have been subjected to high evolutionary rates. However, key residues involved in the interaction with the small RNA and mRNA cleavage in the canonical Argonautes were more conserved in the FL-Agos than in the Piwi Argonautes. Whether this is related to specialized functions and adaptations to parasitism in Neodermatans remains unclear. In conclusion, differences detected in gene conservation, sequence and structure of the Argonaute family suggest tentative biological and evolutionary diversifications that are unique to Platyhelminthes. The remarkable divergencies in the small RNA pathways between free-living and parasitic flatworms indicate that they may have been involved in the adaptation to parasitism of Neodermatans.
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Affiliation(s)
- Santiago Fontenla
- Departamento de Genética, Facultad de Medicina, Universidad de la República (UDELAR), Montevideo, Uruguay
| | | | - Jose F Tort
- Departamento de Genética, Facultad de Medicina, Universidad de la República (UDELAR), Montevideo, Uruguay
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Larocca D, Lee J, West MD, Labat I, Sternberg H. No Time to Age: Uncoupling Aging from Chronological Time. Genes (Basel) 2021; 12:611. [PMID: 33919082 PMCID: PMC8143125 DOI: 10.3390/genes12050611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 12/20/2022] Open
Abstract
Multicellular life evolved from simple unicellular organisms that could replicate indefinitely, being essentially ageless. At this point, life split into two fundamentally different cell types: the immortal germline representing an unbroken lineage of cell division with no intrinsic endpoint and the mortal soma, which ages and dies. In this review, we describe the germline as clock-free and the soma as clock-bound and discuss aging with respect to three DNA-based cellular clocks (telomeric, DNA methylation, and transposable element). The ticking of these clocks corresponds to the stepwise progressive limitation of growth and regeneration of somatic cells that we term somatic restriction. Somatic restriction acts in opposition to strategies that ensure continued germline replication and regeneration. We thus consider the plasticity of aging as a process not fixed to the pace of chronological time but one that can speed up or slow down depending on the rate of intrinsic cellular clocks. We further describe how germline factor reprogramming might be used to slow the rate of aging and potentially reverse it by causing the clocks to tick backward. Therefore, reprogramming may eventually lead to therapeutic strategies to treat degenerative diseases by altering aging itself, the one condition common to us all.
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Affiliation(s)
| | - Jieun Lee
- AgeX Therapeutics Inc., Alameda, CA 94501, USA; (J.L.); (M.D.W.); (I.L.); (H.S.)
| | - Michael D. West
- AgeX Therapeutics Inc., Alameda, CA 94501, USA; (J.L.); (M.D.W.); (I.L.); (H.S.)
| | - Ivan Labat
- AgeX Therapeutics Inc., Alameda, CA 94501, USA; (J.L.); (M.D.W.); (I.L.); (H.S.)
| | - Hal Sternberg
- AgeX Therapeutics Inc., Alameda, CA 94501, USA; (J.L.); (M.D.W.); (I.L.); (H.S.)
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24
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Lakshmanan V, Sujith TN, Bansal D, Shivaprasad PV, Palakodeti D, Krishna S. Comprehensive annotation and characterization of planarian tRNA and tRNA-derived fragments (tRFs). RNA (NEW YORK, N.Y.) 2021; 27:477-495. [PMID: 33446492 PMCID: PMC7962491 DOI: 10.1261/rna.077701.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
tRNA-derived fragments (tRFs) have recently gained a lot of scientific interest due to their diverse regulatory roles in several cellular processes. However, their function in dynamic biological processes such as development and regeneration remains unexplored. Here, we show that tRFs are dynamically expressed during planarian regeneration, suggesting a possible role for these small RNAs in the regulation of regeneration. In order to characterize planarian tRFs, we first annotated 457 tRNAs in S. mediterranea combining two tRNA prediction algorithms. Annotation of tRNAs facilitated the identification of three main species of tRFs in planarians-the shorter tRF-5s and itRFs, and the abundantly expressed 5'-tsRNAs. Spatial profiling of tRFs in sequential transverse sections of planarians revealed diverse expression patterns of these small RNAs, including those that are enriched in the head and pharyngeal regions. Expression analysis of these tRF species revealed dynamic expression of these small RNAs over the course of regeneration suggesting an important role in planarian anterior and posterior regeneration. Finally, we show that 5'-tsRNA in planaria interact with all three SMEDWI proteins and an involvement of AGO1 in the processing of itRFs. In summary, our findings implicate a novel role for tRFs in planarian regeneration, highlighting their importance in regulating complex systemic processes. Our study adds to the catalog of posttranscriptional regulatory systems in planaria, providing valuable insights on the biogenesis and the function of tRFs in neoblasts and planarian regeneration.
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MESH Headings
- Algorithms
- Animals
- Argonaute Proteins/genetics
- Argonaute Proteins/metabolism
- Base Pairing
- Base Sequence
- Gene Expression Regulation
- Helminth Proteins/genetics
- Helminth Proteins/metabolism
- Molecular Sequence Annotation
- Nucleic Acid Conformation
- Planarians/genetics
- Planarians/metabolism
- RNA, Helminth/chemistry
- RNA, Helminth/classification
- RNA, Helminth/genetics
- RNA, Helminth/metabolism
- RNA, Small Untranslated/chemistry
- RNA, Small Untranslated/classification
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/classification
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Regeneration/genetics
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Affiliation(s)
- Vairavan Lakshmanan
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
- SASTRA University, 613401 Thanjavur, India
| | - T N Sujith
- National Centre for Biological Sciences (NCBS), 560065 Bangalore, India
| | - Dhiru Bansal
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
| | | | - Dasaradhi Palakodeti
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
| | - Srikar Krishna
- Institute for Stem Cell Science and Regenerative Medicine (inStem), 560065 Bangalore, India
- SASTRA University, 613401 Thanjavur, India
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25
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Molinaro AM, Lindsay‐Mosher N, Pearson BJ. Identification of TOR-responsive slow-cycling neoblasts in planarians. EMBO Rep 2021; 22:e50292. [PMID: 33511776 PMCID: PMC7926258 DOI: 10.15252/embr.202050292] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 11/19/2020] [Accepted: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
Epimorphic regeneration commonly relies on the activation of reserved 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 revisit 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 identify 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 h post-amputation. At this time, RNAlow neoblasts proliferate in a TOR-dependent manner. Additionally, knockdown of the tumour suppressor Lrig-1, which is enriched in RNAlow neoblasts, results in RNAlow neoblast growth and hyperproliferation at homeostasis, and ultimately delays regeneration. We propose that slow-cycling RNAlow neoblasts represent a regeneration-reserved neoblast population.
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Affiliation(s)
- Alyssa M Molinaro
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
- Present address:
Department of Systems BiologyHarvard Medical SchoolBostonMAUSA
| | - Nicole Lindsay‐Mosher
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Bret J Pearson
- Program in Developmental and Stem Cell BiologyHospital for Sick ChildrenTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
- Ontario Institute for Cancer ResearchTorontoONCanada
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26
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Stelman CR, Smith BM, Chandra B, Roberts-Galbraith RH. CBP/p300 homologs CBP2 and CBP3 play distinct roles in planarian stem cell function. Dev Biol 2021; 473:130-143. [PMID: 33607113 DOI: 10.1016/j.ydbio.2021.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 11/19/2022]
Abstract
Chromatin modifications function as critical regulators of gene expression and cellular identity, especially in the regulation and maintenance of the pluripotent state. However, many studies of chromatin modification in stem cells-and pluripotent stem cells in particular-are performed in mammalian stem cell culture, an in vitro condition mimicking a very transient state during mammalian development. Thus, new models for studying pluripotent stem cells in vivo could be helpful for understanding the roles of chromatin modification, for confirming prior in vitro studies, and for exploring evolution of the pluripotent state. The freshwater flatworm, Schmidtea mediterranea, is an excellent model for studying adult pluripotent stem cells, particularly in the context of robust, whole-body regeneration. To identify chromatin modifying and remodeling enzymes critical for planarian regeneration and stem cell maintenance, we took a candidate approach and screened planarian homologs of 25 genes known to regulate chromatin biology in other organisms. Through our study, we identified six genes with novel functions in planarian homeostasis, regeneration, and behavior. Of the list of genes characterized, we identified five planarian homologs of the mammalian CREB-Binding Protein (CBP) and p300 family of histone acetyltransferases, representing an expansion of this family in planarians. We find that two planarian CBP family members are required for planarian survival, with knockdown of Smed-CBP2 and Smed-CBP3 causing distinct defects in stem cell maintenance or function. Loss of CBP2 causes a quick, dramatic loss of stem cells, while knockdown of CBP3 affects stem cells more narrowly, influencing differentiation of several cell types that include neuronal subtypes and cells of the eye. Further, we find that Smed-CBP1 is required for planarian fissioning behavior. We propose that the division of labor among a diversified CBP family in planarians presents an opportunity to dissect specific functions of a broadly important histone acetyltransferase family.
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Affiliation(s)
- Clara R Stelman
- Department of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Britessia M Smith
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Bidushi Chandra
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Rachel H Roberts-Galbraith
- Department of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Cellular Biology, University of Georgia, Athens, GA, USA.
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27
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Xu CM, Sun SC. Expression of Piwi Genes during the Regeneration of Lineus sanguineus (Nemertea, Pilidiophora, Heteronemertea). Genes (Basel) 2020; 11:genes11121484. [PMID: 33321919 PMCID: PMC7764242 DOI: 10.3390/genes11121484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/18/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022] Open
Abstract
The transposon silencer piwi genes play important roles in germline determination and maintenance, gametogenesis, and stem-cell self-renewal, and the expression of certain piwi genes is indispensable for regeneration. Knowledge about piwi genes is needed for phylum Nemertea, which contains members (e.g., Lineus sanguineus) with formidable regeneration capacity. By searching the L. sanguineus genome, we identified six Argonaute genes including three ago (Ls-Ago2, Ls-Ago2a, and Ls-Ago2b) and three piwi (Ls-piwi1, Ls-piwi2, and Ls-piwi3) genes. In situ hybridization revealed that, in intact females, Ls-piwi2 and Ls-piwi3 were not expressed, while Ls-piwi1 was expressed in ovaries. During regeneration, Ls-piwi1 and Ls-pcna (proliferating cell nuclear antigen) had strong and similar expressions. The expression of Ls-piwi1 became indetectable while Ls-pcna continued to be expressed when the differentiation of new organs was finished. During anterior regeneration, expression signals of Ls-piwi2 and Ls-piwi3 were weak and only detected in the blastema stage. During posterior regeneration, no expression was observed for Ls-piwi2. To date, no direct evidence has been found for the existence of congenital stem cells in adult L. sanguineus. The “pluripotent cells” in regenerating tissues are likely to be dedifferentiated from other type(s) of cells.
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28
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Cao Z, Rosenkranz D, Wu S, Liu H, Pang Q, Zhang X, Liu B, Zhao B. Different classes of small RNAs are essential for head regeneration in the planarian Dugesia japonica. BMC Genomics 2020; 21:876. [PMID: 33287698 PMCID: PMC7722302 DOI: 10.1186/s12864-020-07234-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 11/17/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Planarians reliably regenerate all body parts after injury, including a fully functional head and central nervous system. But until now, the expression dynamics and functional role of miRNAs and other small RNAs during the process of head regeneration are not well understood. Furthermore, little is known about the evolutionary conservation of the relevant small RNAs pathways, rendering it difficult to assess whether insights from planarians will apply to other taxa. RESULTS In this study, we applied high throughput sequencing to identify miRNAs, tRNA fragments and piRNAs that are dynamically expressed during head regeneration in Dugesia japonica. We further show that knockdown of selected small RNAs, including three novel Dugesia-specific miRNAs, during head regeneration induces severe defects including abnormally small-sized eyes, cyclopia and complete absence of eyes. CONCLUSIONS Our findings suggest that a complex pool of small RNAs takes part in the process of head regeneration in Dugesia japonica and provide novel insights into global small RNA expression profiles and expression changes in response to head amputation. Our study reveals the evolutionary conserved role of miR-124 and brings further promising candidate small RNAs into play that might unveil new avenues for inducing restorative programs in non-regenerative organisms via small RNA mimics based therapies.
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Affiliation(s)
- Zhonghong Cao
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - David Rosenkranz
- grid.5802.f0000 0001 1941 7111Institute of Organismic and Molecular Evolution (iOME), Anthropology, Anselm-Franz-von-Bentzel-Weg 7, Johannes Gutenberg University, 55099 Mainz, Germany
| | - Suge Wu
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - Hongjin Liu
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - Qiuxiang Pang
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - Xiufang Zhang
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - Baohua Liu
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
| | - Bosheng Zhao
- grid.412509.b0000 0004 1808 3414School of Life Sciences, Shandong University of Technology, 266 Xincun Western Road, Zibo, 255049 People’s Republic of China
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29
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Burrows JTA, Depierreux D, Nibert ML, Pearson BJ. A Novel Taxon of Monosegmented Double-Stranded RNA Viruses Endemic to Triclad Flatworms. J Virol 2020; 94:e00623-20. [PMID: 32907972 PMCID: PMC7592200 DOI: 10.1128/jvi.00623-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022] Open
Abstract
Freshwater planarians, flatworms from order Tricladida, are experimental models of stem cell biology and tissue regeneration. An aspect of their biology that remains less well studied is their relationship with viruses that may infect them. In this study, we identified a taxon of monosegmented double-stranded RNA (dsRNA) viruses in five planarian species, including the well-characterized model Schmidtea mediterranea Sequences for the S. mediterranea virus (abbreviated SmedTV for S. mediterranea tricladivirus) were found in public transcriptome data from multiple institutions, indicating that SmedTV is prevalent in S. mediterranea lab colonies, though without causing evident disease. The presence of SmedTV in discrete cells was shown through in situ hybridization methods for detecting the viral RNA. SmedTV-staining cells were found to be concentrated in neural structures (eyes and brain) but were also scattered in other worm tissues as well. In contrast, few SmedTV-staining cells were seen in stem cell compartments (also consistent with RNA sequencing data) or early blastema tissue. RNA interference (RNAi) targeted to the SmedTV sequence led to apparent cure of infection, though effects on worm health or behavior were not observed. Efforts to transmit SmedTV horizontally through microinjection were unsuccessful. Based on these findings, we conclude that SmedTV infects S. mediterranea in a persistent manner and undergoes vertical transmission to progeny worms during serial passage in lab colonies. The utility of S. mediterranea as a regeneration model, coupled with the apparent capacity of SmedTV to evade normal host immune/RNAi defenses under standard conditions, argues that further studies are warranted to explore this newly recognized virus-host system.IMPORTANCE Planarians are freshwater flatworms, related more distantly to tapeworms and flukes, and have been developed as models to study the molecular mechanisms of stem cell biology and tissue regeneration. These worms live in aquatic environments, where they are likely to encounter a variety of viruses, bacteria, and eukaryotic organisms with pathogenic potential. How the planarian immune system has evolved to cope with these potential pathogens is not well understood, and only two types of planarian viruses have been described to date. Here, we report discovery and inaugural studies of a novel taxon of dsRNA viruses in five different planarian species. The virus in the best-characterized model species, Schmidtea mediterranea, appears to persist long term in that host while avoiding endogenous antiviral or RNAi mechanisms. The S. mediterranea virus-host system thus seems to offer opportunity for gaining new insights into host defenses and their evolution in an important lab model.
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Affiliation(s)
- Jeffrey T A Burrows
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, Ontario, Canada
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
| | - Delphine Depierreux
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Max L Nibert
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Bret J Pearson
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, Ontario, Canada
- Ontario Institute for Cancer Research, Toronto, Ontario, Canada
- University of Toronto, Department of Molecular Genetics, Toronto, Ontario, Canada
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30
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McElhinney JMWR, Hasan A, Sajini AA. The epitranscriptome landscape of small noncoding RNAs in stem cells. Stem Cells 2020; 38:1216-1228. [PMID: 32598085 PMCID: PMC7586957 DOI: 10.1002/stem.3233] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/04/2020] [Accepted: 05/11/2020] [Indexed: 12/14/2022]
Abstract
Stem cells (SCs) are unique cells that have an inherent ability to self‐renew or differentiate. Both fate decisions are strongly regulated at the molecular level via intricate signaling pathways. The regulation of signaling networks promoting self‐renewal or differentiation was thought to be largely governed by the action of transcription factors. However, small noncoding RNAs (ncRNAs), such as vault RNAs, and their post‐transcriptional modifications (the epitranscriptome) have emerged as additional regulatory layers with essential roles in SC fate decisions. RNA post‐transcriptional modifications often modulate RNA stability, splicing, processing, recognition, and translation. Furthermore, modifications on small ncRNAs allow for dual regulation of RNA activity, at both the level of biogenesis and RNA‐mediated actions. RNA post‐transcriptional modifications act through structural alterations and specialized RNA‐binding proteins (RBPs) called writers, readers, and erasers. It is through SC‐context RBPs that the epitranscriptome coordinates specific functional roles. Small ncRNA post‐transcriptional modifications are today exploited by different mechanisms to facilitate SC translational studies. One mechanism readily being studied is identifying how SC‐specific RBPs of small ncRNAs regulate fate decisions. Another common practice of using the epitranscriptome for regenerative applications is using naturally occurring post‐transcriptional modifications on synthetic RNA to generate induced pluripotent SCs. Here, we review exciting insights into how small ncRNA post‐transcriptional modifications control SC fate decisions in development and disease. We hope, by illustrating how essential the epitranscriptome and their associated proteome are in SCs, they would be considered as novel tools to propagate SCs for regenerative medicine.
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Affiliation(s)
- James M W R McElhinney
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Ayesha Hasan
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Abdulrahim A Sajini
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
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31
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Kim IV, Riedelbauch S, Kuhn CD. The piRNA pathway in planarian flatworms: new model, new insights. Biol Chem 2020; 401:1123-1141. [DOI: 10.1515/hsz-2019-0445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/12/2020] [Indexed: 12/22/2022]
Abstract
AbstractPIWI-interacting RNAs (piRNAs) are small regulatory RNAs that associate with members of the PIWI clade of the Argonaute superfamily of proteins. piRNAs are predominantly found in animal gonads. There they silence transposable elements (TEs), regulate gene expression and participate in DNA methylation, thus orchestrating proper germline development. Furthermore, PIWI proteins are also indispensable for the maintenance and differentiation capabilities of pluripotent stem cells in free-living invertebrate species with regenerative potential. Thus, PIWI proteins and piRNAs seem to constitute an essential molecular feature of somatic pluripotent stem cells and the germline. In keeping with this hypothesis, both PIWI proteins and piRNAs are enriched in neoblasts, the adult stem cells of planarian flatworms, and their presence is a prerequisite for the proper regeneration and perpetual tissue homeostasis of these animals. The piRNA pathway is required to maintain the unique biology of planarians because, in analogy to the animal germline, planarian piRNAs silence TEs and ensure stable genome inheritance. Moreover, planarian piRNAs also contribute to the degradation of numerous protein-coding transcripts, a function that may be critical for neoblast differentiation. This review gives an overview of the planarian piRNA pathway and of its crucial function in neoblast biology.
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Affiliation(s)
- Iana V. Kim
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Sebastian Riedelbauch
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
| | - Claus-D. Kuhn
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
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Abstract
Targeted cancer therapy aims to achieve specific elimination of cancerous but not normal cells. Recently, PIWI proteins, a subfamily of the PAZ-PIWI domain (PPD) protein family, have emerged as promising candidates for targeted cancer therapy. PPD proteins are essential for small noncoding RNA pathways. The Argonaute subfamily partners with microRNA and small interfering RNA, whereas the PIWI subfamily partners with PIWI-interacting RNA (piRNA). Both PIWI proteins and piRNA are mostly expressed in the germline and best known for their function in transposon silencing, with no detectable function in mammalian somatic tissues. However, PIWI proteins become aberrantly expressed in multiple types of somatic cancers, thus gaining interest in targeted therapy. Despite this, little is known about the regulatory mechanism of PIWI proteins in cancer. Here we report that one of the four PIWI proteins in humans, PIWIL1, is highly expressed in gastric cancer tissues and cell lines. Knocking out the PIWIL1 gene (PIWIL1-KO) drastically reduces gastric cancer cell proliferation, migration, metastasis, and tumorigenesis. RNA deep sequencing of gastric cancer cell line SNU-1 reveals that KO significantly changes the transcriptome, causing the up-regulation of most of its associated transcripts. Surprisingly, few bona fide piRNAs exist in gastric cancer cells. Furthermore, abolishing the piRNA-binding activity of PIWIL1 does not affect its oncogenic function. Thus, PIWIL1 function in gastric cancer cells is independent of piRNA. This piRNA-independent regulation involves interaction with the UPF1-mediated nonsense-mediated mRNA decay (NMD) mechanism. Altogether, our findings reveal a piRNA-independent function of PIWIL1 in promoting gastric cancer.
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33
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Kashima M, Agata K, Shibata N. What is the role of PIWI family proteins in adult pluripotent stem cells? Insights from asexually reproducing animals, planarians. Dev Growth Differ 2020; 62:407-422. [PMID: 32621324 DOI: 10.1111/dgd.12688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/26/2020] [Accepted: 06/09/2020] [Indexed: 02/06/2023]
Abstract
Planarians have a remarkable regenerative ability owing to their adult pluripotent stem cells (aPSCs), which are called "neoblasts." Planarians maintain a considerable number of neoblasts throughout their adulthood to supply differentiated cells for the maintenance of tissue homeostasis and asexual reproduction (fission followed by regeneration). Thus, planarians serve as a good model to study the regulatory mechanisms of in vivo aPSCs. In asexually reproducing invertebrates, such as sponge, Hydra, and planaria, piwi family genes are the markers most commonly expressed in aPSCs. While piwi family genes are known as guardians against transposable elements in the germline cells of animals that only sexually propagate, their functions in the aPSC system have remained elusive. In this review, we introduce recent knowledge on the PIWI family proteins in the aPSC system in planarians and other organisms and discuss how PIWI family proteins contribute to the regulation of the aPSC system.
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Affiliation(s)
- Makoto Kashima
- College of Science and Engineering, Aoyama Gakuin University, Sagamihara Chuo Ku, Japan
| | - Kiyokazu Agata
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Norito Shibata
- Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College, Tsuyama-City, Japan
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Senescence and Longevity of Sea Urchins. Genes (Basel) 2020; 11:genes11050573. [PMID: 32443861 PMCID: PMC7288282 DOI: 10.3390/genes11050573] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 11/30/2022] Open
Abstract
Sea urchins are a minor class of marine invertebrates that share genetic similarities with humans. For example, the sea urchin species Strongylocentrotus purpuratus is estimated to have 23,300 genes in which the majority of vertebrate gene families are enveloped. Some of the sea urchin species can demonstrate extreme longevity, such as Mesocentrotus franciscanus, living for well over 100 years. Comparing human to sea urchin aging suggests that the latter do not fit within the classic understanding of biological aging, as both long- and short-lived sea urchin species demonstrate negligible senescence. Sea urchins are highly regenerative organisms. Adults can regenerate external appendages and can maintain their regenerative abilities throughout life. They grow indeterminately and reproduce throughout their entire adult life. Both long- and short-lived species do not exhibit age-associated telomere shortening and display telomerase activity in somatic tissues regardless of age. Aging S. purpuratus urchins show changes in expression patterns of protein coding genes that are involved in several fundamental cellular functions such as the ubiquitin-proteasome system, signaling pathways, translational regulation, and electron transport chain. Sea urchin longevity and senescence research is a new and promising field that holds promise for the understanding of aging in vertebrates and can increase our understanding of human longevity and of healthy aging.
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Kimball C, Powers K, Dustin J, Poirier V, Pellettieri J. The exon junction complex is required for stem and progenitor cell maintenance in planarians. Dev Biol 2020; 457:119-127. [PMID: 31557470 PMCID: PMC8544814 DOI: 10.1016/j.ydbio.2019.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/31/2019] [Accepted: 09/20/2019] [Indexed: 12/12/2022]
Abstract
Named for its assembly near exon-exon junctions during pre-mRNA splicing, the exon junction complex (EJC) regulates multiple aspects of RNA biochemistry, including export of spliced mRNAs from the nucleus and translation. Transcriptome analyses have revealed broad EJC occupancy of spliced metazoan transcripts, yet inhibition of core subunits has been linked to surprisingly specific phenotypes and a growing number of studies support gene-specific regulatory roles. Here we report results from a classroom-based RNAi screen revealing the EJC is necessary for regeneration in the planarian flatworm Schmidtea mediterranea. RNAi animals rapidly lost the stem and progenitor cells that drive formation of new tissue during both regeneration and cell turnover, but exhibited normal amputation-induced changes in gene expression in differentiated tissues. Together with previous reports that partial loss of EJC function causes stem cell defects in Drosophila and mice, our observations implicate the EJC as a conserved, posttranscriptional regulator of gene expression in stem cell lineages. This work also highlights the combined educational and scientific impacts of discovery-based research in the undergraduate biology curriculum.
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Affiliation(s)
- Casey Kimball
- Department of Biology, Keene State College, Keene, NH, USA
| | - Kaleigh Powers
- Department of Biology, Keene State College, Keene, NH, USA
| | - John Dustin
- Department of Biology, Keene State College, Keene, NH, USA
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Kim IV, Ross EJ, Dietrich S, Döring K, Sánchez Alvarado A, Kuhn CD. Efficient depletion of ribosomal RNA for RNA sequencing in planarians. BMC Genomics 2019; 20:909. [PMID: 31783730 PMCID: PMC6884822 DOI: 10.1186/s12864-019-6292-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The astounding regenerative abilities of planarian flatworms prompt steadily growing interest in examining their molecular foundation. Planarian regeneration was found to require hundreds of genes and is hence a complex process. Thus, RNA interference followed by transcriptome-wide gene expression analysis by RNA-seq is a popular technique to study the impact of any particular planarian gene on regeneration. Typically, the removal of ribosomal RNA (rRNA) is the first step of all RNA-seq library preparation protocols. To date, rRNA removal in planarians was primarily achieved by the enrichment of polyadenylated (poly(A)) transcripts. However, to better reflect transcriptome dynamics and to cover also non-poly(A) transcripts, a procedure for the targeted removal of rRNA in planarians is needed. RESULTS In this study, we describe a workflow for the efficient depletion of rRNA in the planarian model species S. mediterranea. Our protocol is based on subtractive hybridization using organism-specific probes. Importantly, the designed probes also deplete rRNA of other freshwater triclad families, a fact that considerably broadens the applicability of our protocol. We tested our approach on total RNA isolated from stem cells (termed neoblasts) of S. mediterranea and compared ribodepleted libraries with publicly available poly(A)-enriched ones. Overall, mRNA levels after ribodepletion were consistent with poly(A) libraries. However, ribodepleted libraries revealed higher transcript levels for transposable elements and histone mRNAs that remained underrepresented in poly(A) libraries. As neoblasts experience high transposon activity this suggests that ribodepleted libraries better reflect the transcriptional dynamics of planarian stem cells. Furthermore, the presented ribodepletion procedure was successfully expanded to the removal of ribosomal RNA from the gram-negative bacterium Salmonella typhimurium. CONCLUSIONS The ribodepletion protocol presented here ensures the efficient rRNA removal from low input total planarian RNA, which can be further processed for RNA-seq applications. Resulting libraries contain less than 2% rRNA. Moreover, for a cost-effective and efficient removal of rRNA prior to sequencing applications our procedure might be adapted to any prokaryotic or eukaryotic species of choice.
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Affiliation(s)
- Iana V Kim
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany.
| | - Eric J Ross
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, 64110, USA
- Howard Hughes Medical Institute, Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, 64110, USA
| | - Sascha Dietrich
- Core Unit Systems Medicine, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany
| | - Kristina Döring
- Core Unit Systems Medicine, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Str. 2, 97080, Würzburg, Germany
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, 64110, USA
- Howard Hughes Medical Institute, Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO, 64110, USA
| | - Claus-D Kuhn
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, Universitätsstrasse 30, 95447, Bayreuth, Germany.
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piRNA-Guided CRISPR-like Immunity in Eukaryotes. Trends Immunol 2019; 40:998-1010. [DOI: 10.1016/j.it.2019.09.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 09/17/2019] [Accepted: 09/17/2019] [Indexed: 02/07/2023]
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Kim IV, Duncan EM, Ross EJ, Gorbovytska V, Nowotarski SH, Elliott SA, Sánchez Alvarado A, Kuhn CD. Planarians recruit piRNAs for mRNA turnover in adult stem cells. Genes Dev 2019; 33:1575-1590. [PMID: 31537626 PMCID: PMC6824462 DOI: 10.1101/gad.322776.118] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 09/03/2019] [Indexed: 12/20/2022]
Abstract
In this study, Kim et al. set out to elucidate the molecular details of how PIWI proteins in planarian flatworms contribute to stem cell function and regeneration. Using novel biochemical tools, such as IP-seq, ribodepletion, HITS-CLIP, and SHAPE-MaP, the authors show that PIWI proteins enable planarians to repurpose piRNAs for critical roles in neoblast mRNA turnover. PIWI proteins utilize small RNAs called piRNAs to silence transposable elements, thereby protecting germline integrity. In planarian flatworms, PIWI proteins are essential for regeneration, which requires adult stem cells termed neoblasts. Here, we characterize planarian piRNAs and examine the roles of PIWI proteins in neoblast biology. We find that the planarian PIWI proteins SMEDWI-2 and SMEDWI-3 cooperate to degrade active transposons via the ping-pong cycle. Unexpectedly, we discover that SMEDWI-3 plays an additional role in planarian mRNA surveillance. While SMEDWI-3 degrades numerous neoblast mRNAs in a homotypic ping-pong cycle, it is also guided to another subset of neoblast mRNAs by antisense piRNAs and binds these without degrading them. Mechanistically, the distinct activities of SMEDWI-3 are primarily dictated by the degree of complementarity between target mRNAs and antisense piRNAs. Thus, PIWI proteins enable planarians to repurpose piRNAs for potentially critical roles in neoblast mRNA turnover.
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Affiliation(s)
- Iana V Kim
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, 95447 Bayreuth, Germany
| | - Elizabeth M Duncan
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Eric J Ross
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.,Howard Hughes Medical Institute, Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Vladyslava Gorbovytska
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, 95447 Bayreuth, Germany
| | | | - Sarah A Elliott
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.,Howard Hughes Medical Institute, Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Claus-D Kuhn
- Gene regulation by Non-coding RNA, Elite Network of Bavaria and University of Bayreuth, 95447 Bayreuth, Germany
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Wang C, Yang ZZ, Guo FH, Shi S, Han XS, Zeng A, Lin H, Jing Q. Heat shock protein DNAJA1 stabilizes PIWI proteins to support regeneration and homeostasis of planarian Schmidtea mediterranea. J Biol Chem 2019; 294:9873-9887. [PMID: 31076507 DOI: 10.1074/jbc.ra118.004445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 04/25/2019] [Indexed: 12/16/2022] Open
Abstract
PIWI proteins are key regulators of germline and somatic stem cells throughout different evolutionary lineages. However, how PIWI proteins themselves are regulated remains largely unknown. To identify candidate proteins that interact with PIWI proteins and regulate their stability, here we established a yeast two-hybrid (Y2H) assay in the planarian species Schmidtea mediterranea We show that DNAJA1, a heat shock protein 40 family member, interacts with the PIWI protein SMEDWI-2, as validated by the Y2H screen and co-immunoprecipitation assays. We found that DNAJA1 is enriched in planarian adult stem cells, the nervous system, and intestinal tissues. DNAJA1-knockdown abolished planarian regeneration and homeostasis, compromised stem cell maintenance and PIWI-interacting RNA (piRNA) biogenesis, and deregulated SMEDWI-1/2 target genes. Mechanistically, we observed that DNAJA1 is required for the stability of SMEDWI-1 and SMEDWI-2 proteins. Furthermore, we noted that human DNAJA1 binds to Piwi-like RNA-mediated gene silencing 1 (PIWIL1) and is required for PIWIL1 stability in human gastric cancer cells. In summary, our results reveal not only an evolutionarily conserved functional link between PIWI and DNAJA1 that is essential for PIWI protein stability and piRNA biogenesis, but also an important role of DNAJA1 in the control of proteins involved in stem cell regulation.
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Affiliation(s)
- Chen Wang
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China.,the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Zhen-Zhen Yang
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Fang-Hao Guo
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Shuo Shi
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China
| | - Xiao-Shuai Han
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - An Zeng
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
| | - Haifan Lin
- From the Shanghai Institute of Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China, .,the Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut 06511
| | - Qing Jing
- the CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China, and
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Issigonis M, Newmark PA. From worm to germ: Germ cell development and regeneration in planarians. Curr Top Dev Biol 2019; 135:127-153. [DOI: 10.1016/bs.ctdb.2019.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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41
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Weng C, Kosalka J, Berkyurek AC, Stempor P, Feng X, Mao H, Zeng C, Li WJ, Yan YH, Dong MQ, Morero NR, Zuliani C, Barabas O, Ahringer J, Guang S, Miska EA. The USTC co-opts an ancient machinery to drive piRNA transcription in C. elegans. Genes Dev 2019; 33:90-102. [PMID: 30567997 PMCID: PMC6317315 DOI: 10.1101/gad.319293.118] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 10/19/2018] [Indexed: 01/15/2023]
Abstract
Piwi-interacting RNAs (piRNAs) engage Piwi proteins to suppress transposons and nonself nucleic acids and maintain genome integrity and are essential for fertility in a variety of organisms. In Caenorhabditis elegans, most piRNA precursors are transcribed from two genomic clusters that contain thousands of individual piRNA transcription units. While a few genes have been shown to be required for piRNA biogenesis, the mechanism of piRNA transcription remains elusive. Here we used functional proteomics approaches to identify an upstream sequence transcription complex (USTC) that is essential for piRNA biogenesis. The USTC contains piRNA silencing-defective 1 (PRDE-1), SNPC-4, twenty-one-U fouled-up 4 (TOFU-4), and TOFU-5. The USTC forms unique piRNA foci in germline nuclei and coats the piRNA cluster genomic loci. USTC factors associate with the Ruby motif just upstream of type I piRNA genes. USTC factors are also mutually dependent for binding to the piRNA clusters and forming the piRNA foci. Interestingly, USTC components bind differentially to piRNAs in the clusters and other noncoding RNA genes. These results reveal the USTC as a striking example of the repurposing of a general transcription factor complex to aid in genome defense against transposons.
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Affiliation(s)
- Chenchun Weng
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Joanna Kosalka
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Ahmet C Berkyurek
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Przemyslaw Stempor
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Xuezhu Feng
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Hui Mao
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Chenming Zeng
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Wen-Jun Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Yong-Hong Yan
- National Institute of Biological Sciences, Beijing 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing 102206, China
| | - Natalia Rosalía Morero
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Cecilia Zuliani
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Julie Ahringer
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Shouhong Guang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Eric A Miska
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom; Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
- Wellcome Sanger Institute, Cambridge CB10 1SA, United Kingdom
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Schmidt D, Reuter H, Hüttner K, Ruhe L, Rabert F, Seebeck F, Irimia M, Solana J, Bartscherer K. The Integrator complex regulates differential snRNA processing and fate of adult stem cells in the highly regenerative planarian Schmidtea mediterranea. PLoS Genet 2018; 14:e1007828. [PMID: 30557303 PMCID: PMC6312358 DOI: 10.1371/journal.pgen.1007828] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/31/2018] [Accepted: 11/12/2018] [Indexed: 02/07/2023] Open
Abstract
In multicellular organisms, cell type diversity and fate depend on specific sets of transcript isoforms generated by post-transcriptional RNA processing. Here, we used Schmidtea mediterranea, a flatworm with extraordinary regenerative abilities and a large pool of adult stem cells, as an in vivo model to study the role of Uridyl-rich small nuclear RNAs (UsnRNAs), which participate in multiple RNA processing reactions including splicing, in stem cell regulation. We characterized the planarian UsnRNA repertoire, identified stem cell-enriched variants and obtained strong evidence for an increased rate of UsnRNA 3'-processing in stem cells compared to their differentiated counterparts. Consistently, components of the Integrator complex showed stem cell-enriched expression and their depletion by RNAi disrupted UsnRNA processing resulting in global changes of splicing patterns and reduced processing of histone mRNAs. Interestingly, loss of Integrator complex function disrupted both stem cell maintenance and regeneration of tissues. Our data show that the function of the Integrator complex in UsnRNA 3'-processing is conserved in planarians and essential for maintaining their stem cell pool. We propose that cell type-specific modulation of UsnRNA composition and maturation contributes to in vivo cell fate choices, such as stem cell self-renewal in planarians.
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Affiliation(s)
- David Schmidt
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
- * E-mail: (DS); (KB)
| | - Hanna Reuter
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Katja Hüttner
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Larissa Ruhe
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Franziska Rabert
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Florian Seebeck
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
| | - Manuel Irimia
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Universitat Pompeu Fabra, Barcelona, Spain
| | - Jordi Solana
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Kerstin Bartscherer
- Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Medical Faculty, University of Münster, Münster, Germany
- Hubrecht Institute for Developmental Biology and Stem Cell Research, CT Utrecht, The Netherlands
- * E-mail: (DS); (KB)
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Zhang R, Jing Y, Zhang H, Niu Y, Liu C, Wang J, Zen K, Zhang CY, Li D. Comprehensive Evolutionary Analysis of the Major RNA-Induced Silencing Complex Members. Sci Rep 2018; 8:14189. [PMID: 30242207 PMCID: PMC6155107 DOI: 10.1038/s41598-018-32635-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 09/12/2018] [Indexed: 01/10/2023] Open
Abstract
RNA-induced silencing complex (RISC) plays a critical role in small interfering RNA (siRNA) and microRNAs (miRNA) pathways. Accumulating evidence has demonstrated that the major RISC members (AGO, DICER, TRBP, PACT and GW182) represent expression discrepancies or multiple orthologues/paralogues in different species. To elucidate their evolutionary characteristics, an integrated evolutionary analysis was performed. Here, animal and plant AGOs were divided into three classes (multifunctional AGOs, siRNA-associated AGOs and piRNA-associated AGOs for animal AGOs and multifunctional AGOs, siRNA-associated AGOs and complementary functioning AGOs for plant AGOs). Animal and plant DICERs were grouped into one class (multifunctional DICERs) and two classes (multifunctional DICERs and siRNA-associated DICERs), respectively. Protista/fungi AGOs or DICERs were specifically associated with the siRNA pathway. Additionally, TRBP/PACT/GW182 were identified only in animals, and all of them functioned in the miRNA pathway. Mammalian AGOs, animal DICERs and chordate TRBP/PACT were found to be monophyletic. A large number of gene duplications were identified in AGO and DICER groups. Taken together, we provide a comprehensive evolutionary analysis, describe a phylogenetic tree-based classification of the major RISC members and quantify their gene duplication events. These findings are potentially useful for classifying RISCs, optimizing species-specific RISCs and developing research model organisms.
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Affiliation(s)
- Rui Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Ying Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Haiyang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Yahan Niu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Chang Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Jin Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Ke Zen
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Chen-Yu Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Donghai Li
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China.
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Rojas-Ríos P, Simonelig M. piRNAs and PIWI proteins: regulators of gene expression in development and stem cells. Development 2018; 145:145/17/dev161786. [PMID: 30194260 DOI: 10.1242/dev.161786] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PIWI proteins and Piwi-interacting RNAs (piRNAs) have established and conserved roles in repressing transposable elements (TEs) in the germline of animals. However, in several biological contexts, a large proportion of piRNAs are not related to TE sequences and, accordingly, functions for piRNAs and PIWI proteins that are independent of TE regulation have been identified. This aspect of piRNA biology is expanding rapidly. Indeed, recent reports have revealed the role of piRNAs in the regulation of endogenous gene expression programs in germ cells, as well as in somatic tissues, challenging dogma in the piRNA field. In this Review, we focus on recent data addressing the biological and developmental functions of piRNAs, highlighting their roles in embryonic patterning, germ cell specification, stem cell biology, neuronal activity and metabolism.
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Affiliation(s)
- Patricia Rojas-Ríos
- mRNA Regulation and Development, IGH, Univ. Montpellier, CNRS, Montpellier 34396, France
| | - Martine Simonelig
- mRNA Regulation and Development, IGH, Univ. Montpellier, CNRS, Montpellier 34396, France
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Jehn J, Gebert D, Pipilescu F, Stern S, Kiefer JST, Hewel C, Rosenkranz D. PIWI genes and piRNAs are ubiquitously expressed in mollusks and show patterns of lineage-specific adaptation. Commun Biol 2018; 1:137. [PMID: 30272016 PMCID: PMC6128900 DOI: 10.1038/s42003-018-0141-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/17/2018] [Indexed: 12/14/2022] Open
Abstract
PIWI proteins and PIWI-interacting RNAs (piRNAs) suppress transposon activity in animals, thus protecting their genomes from detrimental insertion mutagenesis. Here, we reveal that PIWI genes and piRNAs are ubiquitously expressed in mollusks, similar to the situation in arthropods. We describe lineage-specific adaptations of transposon composition in piRNA clusters in the great pond snail and the pacific oyster, likely reflecting differential transposon activity in gastropods and bivalves. We further show that different piRNA clusters with unique transposon composition are dynamically expressed during oyster development. Finally, bioinformatics analyses suggest that different populations of piRNAs presumably bound to different PIWI paralogs participate in homotypic and heterotypic ping-pong amplification loops in a tissue- and sex-specific manner. Together with recent findings from other animal species, our results support the idea that somatic piRNA expression represents the ancestral state in metazoans.
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Affiliation(s)
- Julia Jehn
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - Daniel Gebert
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - Frank Pipilescu
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - Sarah Stern
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - Julian Simon Thilo Kiefer
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - Charlotte Hewel
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany
| | - David Rosenkranz
- Institute of Organismic and Molecular Evolution, Anthropology, Johannes Gutenberg University Mainz, Anselm-Franz-von-Bentzel-Weg 7, 55099, Mainz, Germany.
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Dattani A, Kao D, Mihaylova Y, Abnave P, Hughes S, Lai A, Sahu S, Aboobaker AA. Epigenetic analyses of planarian stem cells demonstrate conservation of bivalent histone modifications in animal stem cells. Genome Res 2018; 28:1543-1554. [PMID: 30143598 PMCID: PMC6169894 DOI: 10.1101/gr.239848.118] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 08/16/2018] [Indexed: 12/14/2022]
Abstract
Planarian flatworms have an indefinite capacity to regenerate missing or damaged body parts owing to a population of pluripotent adult stems cells called neoblasts (NBs). Currently, little is known about the importance of the epigenetic status of NBs and how histone modifications regulate homeostasis and cellular differentiation. We have developed an improved and optimized ChIP-seq protocol for NBs in Schmidtea mediterranea and have generated genome-wide profiles for the active marks H3K4me3 and H3K36me3, and suppressive marks H3K4me1 and H3K27me3. The genome-wide profiles of these marks were found to correlate well with NB gene expression profiles. We found that genes with little transcriptional activity in the NB compartment but which switch on in post-mitotic progeny during differentiation are bivalent, being marked by both H3K4me3 and H3K27me3 at promoter regions. In further support of this hypothesis, bivalent genes also have a high level of paused RNA Polymerase II at the promoter-proximal region. Overall, this study confirms that epigenetic control is important for the maintenance of a NB transcriptional program and makes a case for bivalent promoters as a conserved feature of animal stem cells and not a vertebrate-specific innovation. By establishing a robust ChIP-seq protocol and analysis methodology, we further promote planarians as a promising model system to investigate histone modification–mediated regulation of stem cell function and differentiation.
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Affiliation(s)
- Anish Dattani
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Damian Kao
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Yuliana Mihaylova
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Prasad Abnave
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Samantha Hughes
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Alvina Lai
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Sounak Sahu
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - A Aziz Aboobaker
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
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Post-transcriptional regulation in planarian stem cells. Semin Cell Dev Biol 2018; 87:69-78. [PMID: 29870807 DOI: 10.1016/j.semcdb.2018.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 12/17/2022]
Abstract
Planarians are known for their immense regenerative abilities. A pluripotent stem cell population provides the cellular source for this process, as well as for the homeostatic cell turnover of the animals. These stem cells, known as neoblasts, present striking similarities at the morphological and molecular level to germ cells, but however, give rise to somatic tissue. Many RNA binding proteins known to be important for germ cell biology are also required for neoblast function, highlighting the importance of post-transcriptional regulation for stem cell control. Many of its aspects, including alternative splicing, alternative polyadenylation, translational control and mRNA deadenylation, as well as small RNAs such as microRNAs and piRNA are critical for stem cells. Their inhibition often abrogates both regeneration and cell turnover, resulting in lethality. Some of aspects of post-transcriptional regulation are conserved from planarian to mammalian stem cells.
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Kashima M, Agata K, Shibata N. Searching for non-transposable targets of planarian nuclear PIWI in pluripotent stem cells and differentiated cells. Dev Growth Differ 2018; 60:260-277. [DOI: 10.1111/dgd.12536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Makoto Kashima
- Department of Biophysics; Graduate School of Science; Kyoto University; Kyoto Japan
| | - Kiyokazu Agata
- Department of Biophysics; Graduate School of Science; Kyoto University; Kyoto Japan
| | - Norito Shibata
- Department of Biophysics; Graduate School of Science; Kyoto University; Kyoto Japan
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The Challenges and Opportunities in the Clinical Application of Noncoding RNAs: The Road Map for miRNAs and piRNAs in Cancer Diagnostics and Prognostics. Int J Genomics 2018; 2018:5848046. [PMID: 29854719 PMCID: PMC5952559 DOI: 10.1155/2018/5848046] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/13/2018] [Accepted: 03/25/2018] [Indexed: 12/11/2022] Open
Abstract
Discoveries on nonprotein-coding RNAs have induced a paradigm shift in our overall understanding of gene expression and regulation. We now understand that coding and noncoding RNA machinery work in concert to maintain overall homeostasis. Based on their length, noncoding RNAs are broadly classified into two groups—long (>200 nt) and small noncoding RNAs (<200 nt). These RNAs perform diverse functions—gene regulation, splicing, translation, and posttranscriptional modifications. MicroRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) are two classes of small noncoding RNAs that are now classified as master regulators of gene expression. They have also demonstrated clinical significance as potential biomarkers and therapeutic targets for several diseases, including cancer. Despite these similarities, both these RNAs are generated through contrasting mechanisms, and one of the aims of this review is to cover the distance travelled since their discovery and compare and contrast the various facets of these RNAs. Although these RNAs show tremendous promise as biomarkers, translating the findings from bench to bedside is often met with roadblocks. The second aim of this review therefore is to highlight some of the challenges that hinder application of miRNA and piRNA as in guiding treatment decisions.
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piRNA-like small RNAs are responsible for the maternal-specific knockdown in the ascidian Ciona intestinalis Type A. Sci Rep 2018; 8:5869. [PMID: 29651003 PMCID: PMC5897368 DOI: 10.1038/s41598-018-24319-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/12/2018] [Indexed: 01/11/2023] Open
Abstract
The mRNAs stored in eggs are crucial for embryogenesis. To address functions of maternal mRNAs, we recently reported the novel method MASK (maternal mRNA-specific knockdown), which we used to specifically knockdown maternal transcripts in the ascidian Ciona intestinalis Type A. In MASK, the cis element of a maternal gene is fused with eGFP or Kaede reporter gene, and the cassette is introduced into Ciona genome by transposon-mediated transgenesis. In eggs of the transgenic lines, the maternal expression of the gene whose cis element is used for driving the reporter gene is suppressed. The zygotic expression of the gene is not suppressed, suggesting that the MASK method can distinguish between maternal and zygotic functions of a gene. Here we investigated the cis and trans factors responsible for MASK results. In the ovaries in which knockdown of a maternal gene occurs, a number of antisense small RNAs are expressed that are complementary to the sequence of the knocked-down genes. We suspect that these antisense small RNAs are the factor responsible for MASK results. The antisense small RNAs have several features that are seen in PIWI-interacting RNAs (piRNAs), suggesting that MASK is likely to use a piRNA-mediated mechanism to knock down maternal mRNAs.
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