1
|
Gąsiorowski L, Chai C, Rozanski A, Purandare G, Ficze F, Mizi A, Wang B, Rink JC. Regeneration in the absence of canonical neoblasts in an early branching flatworm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595708. [PMID: 38853907 PMCID: PMC11160568 DOI: 10.1101/2024.05.24.595708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The remarkable regenerative abilities of flatworms are closely linked to neoblasts - adult pluripotent stem cells that are the only division-competent cell type outside of the reproductive system. Although the presence of neoblast-like cells and whole-body regeneration in other animals has led to the idea that these features may represent the ancestral metazoan state, the evolutionary origin of both remains unclear. Here we show that the catenulid Stenostomum brevipharyngium, a member of the earliest-branching flatworm lineage, lacks conventional neoblasts despite being capable of whole-body regeneration and asexual reproduction. Using a combination of single-nuclei transcriptomics, in situ gene expression analysis, and functional experiments, we find that cell divisions are not restricted to a single cell type and are associated with multiple fully differentiated somatic tissues. Furthermore, the cohort of germline multipotency genes, which are considered canonical neoblast markers, are not expressed in dividing cells, but in the germline instead, and we experimentally show that they are neither necessary for proliferation nor regeneration. Overall, our results challenge the notion that canonical neoblasts are necessary for flatworm regeneration and open up the possibility that neoblast-like cells may have evolved convergently in different animals, independent of their regenerative capacity.
Collapse
Affiliation(s)
- Ludwik Gąsiorowski
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Andrei Rozanski
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Gargi Purandare
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Fruzsina Ficze
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Athanasia Mizi
- Institute of Pathology, University Medical Centre Göttingen, Göttingen, Germany
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, USA
| | - Jochen C Rink
- Department of Tissue Dynamics and Regeneration, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| |
Collapse
|
2
|
Sarkies P. The curious case of the disappearing piRNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2024; 15:e1849. [PMID: 38629193 DOI: 10.1002/wrna.1849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/19/2024] [Accepted: 03/22/2024] [Indexed: 04/19/2024]
Abstract
Small non-coding RNAs are key regulators of gene expression across eukaryotes. Piwi-interacting small RNAs (piRNAs) are a specific type of small non-coding RNAs, conserved across animals, which are best known as regulators of genome stability through their ability to target transposable elements for silencing. Despite the near ubiquitous presence of piRNAs in animal lineages, there are some examples where the piRNA pathway has been lost completely, most dramatically in nematodes where loss has occurred in at least four independent lineages. In this perspective I will provide an evaluation of the presence of piRNAs across animals, explaining how it is known that piRNAs are missing from certain organisms. I will then consider possible explanations for why the piRNA pathway might have been lost and evaluate the evidence in favor of each possible mechanism. While it is still impossible to provide definitive answers, these theories will prompt further investigations into why such a highly conserved pathway can nevertheless become dispensable in certain lineages. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs RNA Evolution and Genomics > RNA and Ribonucleoprotein Evolution.
Collapse
Affiliation(s)
- Peter Sarkies
- Department of Biochemistry, University of Oxford, Oxford, UK
| |
Collapse
|
3
|
Spradling AC. The Ancient Origin and Function of Germline Cysts. Results Probl Cell Differ 2024; 71:3-21. [PMID: 37996670 DOI: 10.1007/978-3-031-37936-9_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Gamete production in most animal species is initiated within an evolutionarily ancient multicellular germline structure, the germline cyst, whose interconnected premeiotic cells synchronously develop from a single progenitor arising just downstream from a stem cell. Cysts in mice, Drosophila, and many other animals protect developing sperm, while in females, cysts generate nurse cells that guard sister oocytes from transposons (TEs) and help them grow and build a Balbiani body. However, the origin and extreme evolutionary conservation of germline cysts remains a mystery. We suggest that cysts arose in ancestral animals like Hydra and Planaria whose multipotent somatic and germline stem cells (neoblasts) express genes conserved in all animal germ cells and frequently begin differentiation in cysts. A syncytial state is proposed to help multipotent stem cell chromatin transition to an epigenetic state with heterochromatic domains suitable for TE repression and specialized function. Most modern animals now lack neoblasts but have retained stem cells and cysts in their early germlines, which continue to function using this ancient epigenetic strategy.
Collapse
Affiliation(s)
- Allan C Spradling
- Carnegie Institution for Science/Howard Hughes Medical Institute, Baltimore, MD, USA.
| |
Collapse
|
4
|
Pang LY, DeLuca S, Zhu H, Urban JM, Spradling AC. Chromatin and gene expression changes during female Drosophila germline stem cell development illuminate the biology of highly potent stem cells. eLife 2023; 12:RP90509. [PMID: 37831064 PMCID: PMC10575629 DOI: 10.7554/elife.90509] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023] Open
Abstract
Highly potent animal stem cells either self renew or launch complex differentiation programs, using mechanisms that are only partly understood. Drosophila female germline stem cells (GSCs) perpetuate without change over evolutionary time and generate cystoblast daughters that develop into nurse cells and oocytes. Cystoblasts initiate differentiation by generating a transient syncytial state, the germline cyst, and by increasing pericentromeric H3K9me3 modification, actions likely to suppress transposable element activity. Relatively open GSC chromatin is further restricted by Polycomb repression of testis or somatic cell-expressed genes briefly active in early female germ cells. Subsequently, Neijre/CBP and Myc help upregulate growth and reprogram GSC metabolism by altering mitochondrial transmembrane transport, gluconeogenesis, and other processes. In all these respects GSC differentiation resembles development of the totipotent zygote. We propose that the totipotent stem cell state was shaped by the need to resist transposon activity over evolutionary timescales.
Collapse
Affiliation(s)
- Liang-Yu Pang
- Howard Hughes Medical Institute, Carnegie Institution for ScienceBaltimoreUnited States
| | - Steven DeLuca
- Howard Hughes Medical Institute, Carnegie Institution for ScienceBaltimoreUnited States
| | - Haolong Zhu
- Howard Hughes Medical Institute, Carnegie Institution for ScienceBaltimoreUnited States
| | - John M Urban
- Howard Hughes Medical Institute, Carnegie Institution for ScienceBaltimoreUnited States
| | - Allan C Spradling
- Howard Hughes Medical Institute, Carnegie Institution for ScienceBaltimoreUnited States
| |
Collapse
|
5
|
Lin Y, Suyama R, Kawaguchi S, Iki T, Kai T. Tejas functions as a core component in nuage assembly and precursor processing in Drosophila piRNA biogenesis. J Cell Biol 2023; 222:e202303125. [PMID: 37555815 PMCID: PMC10412688 DOI: 10.1083/jcb.202303125] [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: 03/27/2023] [Revised: 06/11/2023] [Accepted: 07/13/2023] [Indexed: 08/10/2023] Open
Abstract
PIWI-interacting RNAs (piRNAs), which protect genome from the attack by transposons, are produced and amplified in membraneless granules called nuage. In Drosophila, PIWI family proteins, Tudor-domain-containing (Tdrd) proteins, and RNA helicases are assembled and form nuage to ensure piRNA production. However, the molecular functions of the Tdrd protein Tejas (Tej) in piRNA biogenesis remain unknown. Here, we conduct a detailed analysis of the subcellular localization of fluorescently tagged nuage proteins and behavior of piRNA precursors. Our results demonstrate that Tej functions as a core component that recruits Vasa (Vas) and Spindle-E (Spn-E) into nuage granules through distinct motifs, thereby assembling nuage and engaging precursors for further processing. Our study also reveals that the low-complexity region of Tej regulates the mobility of Vas. Based on these results, we propose that Tej plays a pivotal role in piRNA precursor processing by assembling Vas and Spn-E into nuage and modulating the mobility of nuage components.
Collapse
Affiliation(s)
- Yuxuan Lin
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Ritsuko Suyama
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | | | - Taichiro Iki
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Toshie Kai
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| |
Collapse
|
6
|
Chary S, Hayashi R. The absence of core piRNA biogenesis factors does not impact efficient transposon silencing in Drosophila. PLoS Biol 2023; 21:e3002099. [PMID: 37279192 DOI: 10.1371/journal.pbio.3002099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/30/2023] [Indexed: 06/08/2023] Open
Abstract
Organisms require mechanisms to distinguish self and non-self-RNA. This distinction is crucial to initiate the biogenesis of Piwi-interacting RNAs (piRNAs). In Drosophila ovaries, PIWI-guided slicing and the recognition of piRNA precursor transcripts by the DEAD-box RNA helicase Yb are the 2 known mechanisms to licence an RNA for piRNA biogenesis in the germline and the soma, respectively. Both the PIWI proteins and Yb are highly conserved across most Drosophila species and are thought to be essential to the piRNA pathway and for silencing transposons. However, we find that species closely related to Drosophila melanogaster have lost the yb gene, as well as the PIWI gene Ago3. We show that the precursor RNA is still selected in the absence of Yb to abundantly generate transposon antisense piRNAs in the soma. We further demonstrate that Drosophila eugracilis, which lacks Ago3, is completely devoid of ping-pong piRNAs and exclusively produces phased piRNAs in the absence of slicing. Thus, core piRNA pathway genes can be lost in evolution while still maintaining efficient transposon silencing.
Collapse
Affiliation(s)
- Shashank Chary
- John Curtin School of Medical Research, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Rippei Hayashi
- John Curtin School of Medical Research, The Australian National University, Acton, Australian Capital Territory, Australia
- The Shine-Dalgarno Centre for RNA Innovation, The Australian National University, Acton, Australian Capital Territory, Australia
| |
Collapse
|
7
|
Holstein TW. The Hydra stem cell system - Revisited. Cells Dev 2023; 174:203846. [PMID: 37121433 DOI: 10.1016/j.cdev.2023.203846] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/12/2023] [Accepted: 04/25/2023] [Indexed: 05/02/2023]
Abstract
Cnidarians are >600 million years old and are considered the sister group of Bilateria based on numerous molecular phylogenetic studies. Apart from Hydra, the genomes of all major clades of Cnidaria have been uncovered (e.g. Aurelia, Clytia, Nematostella and Acropora) and they reveal a remarkable completeness of the metazoan genomic toolbox. Of particular interest is Hydra, a model system of aging research, regenerative biology, and stem cell biology. With the knowledge gained from scRNA research, it is now possible to characterize the expression profiles of all cell types with great precision. In functional studies, our picture of the Hydra stem cell biology has changed, and we are in the process of obtaining a clear picture of the homeostasis and properties of the different stem cell populations. Even though Hydra is often compared to plant systems, the new data on germline and regeneration, but also on the dynamics and plasticity of the nervous system, show that Hydra with its simple body plan represents in a nutshell the prototype of an animal with stem cell lineages, whose properties correspond in many ways to Bilateria. This review provides an overview of the four stem cell lineages, the two epithelial lineages that constitute the ectoderm and the endoderm, as well as the multipotent somatic interstitial lineage (MPSC) and the germline stem cell lineage (GSC), also known as the interstitial cells of Hydra.
Collapse
Affiliation(s)
- Thomas W Holstein
- Heidelberg University, Centre for Organismal Studies (COS), Molecular Evolution and Genomics, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany.
| |
Collapse
|
8
|
Yao Y, Li Y, Zhu X, Zhao C, Yang L, Huang X, Wang L. The emerging role of the piRNA/PIWI complex in respiratory tract diseases. Respir Res 2023; 24:76. [PMID: 36915129 PMCID: PMC10010017 DOI: 10.1186/s12931-023-02367-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 02/14/2023] [Indexed: 03/16/2023] Open
Abstract
PIWI-interacting RNA (piRNA) is a class of recently discovered small non-coding RNA molecules with a length of 18-33 nt that interacts with the PIWI protein to form the piRNA/PIWI complex. The PIWI family is a subfamily of Argonaute (AGO) proteins that also contain the AGO family which bind to microRNA (miRNA). Recently studies indicate that piRNAs are not specific to in the mammalian germline, they are also expressed in a tissue-specific manner in a variety of human tissues and participated in various of diseases, such as cardiovascular, neurological, and urinary tract diseases, and are especially prevalent in malignant tumors in these systems. However, the functions and abnormal expression of piRNAs in respiratory tract diseases and their underlying mechanisms remain incompletely understood. In this review, we discuss current studies summarizing the biogenetic processes, functions, and emerging roles of piRNAs in respiratory tract diseases, providing a reference value for future piRNA research.
Collapse
Affiliation(s)
- Yizhu Yao
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Yaozhe Li
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Xiayan Zhu
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Chengguang Zhao
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.,School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, China
| | - Lehe Yang
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.
| | - Xiaoying Huang
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.
| | - Liangxing Wang
- Division of Pulmonary Medicine, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.
| |
Collapse
|
9
|
Horjales S, Li Calzi M, Francia ME, Cayota A, Garcia-Silva MR. piRNA pathway evolution beyond gonad context: Perspectives from apicomplexa and trypanosomatids. Front Genet 2023; 14:1129194. [PMID: 36816026 PMCID: PMC9935688 DOI: 10.3389/fgene.2023.1129194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
piRNAs function as genome defense mechanisms against transposable elements insertions within germ line cells. Recent studies have unraveled that piRNA pathways are not limited to germ cells as initially reckoned, but are instead also found in non-gonadal somatic contexts. Moreover, these pathways have also been reported in bacteria, mollusks and arthropods, associated with safeguard of genomes against transposable elements, regulation of gene expression and with direct consequences in axon regeneration and memory formation. In this Perspective we draw attention to early branching parasitic protozoa, whose genome preservation is an essential function as in late eukaryotes. However, little is known about the defense mechanisms of these genomes. We and others have described the presence of putative PIWI-related machinery members in protozoan parasites. We have described the presence of a PIWI-like protein in Trypanosoma cruzi, bound to small non-coding RNAs (sRNAs) as cargo of secreted extracellular vesicles relevant in intercellular communication and host infection. Herein, we put forward the presence of members related to Argonaute pathways in both Trypanosoma cruzi and Toxoplasma gondii. The presence of PIWI-like machinery in Trypansomatids and Apicomplexa, respectively, could be evidence of an ancestral piRNA machinery that evolved to become more sophisticated and complex in multicellular eukaryotes. We propose a model in which ancient PIWI proteins were expressed broadly and had functions independent of germline maintenance. A better understanding of current and ancestral PIWI/piRNAs will be relevant to better understand key mechanisms of genome integrity conservation during cell cycle progression and modulation of host defense mechanisms by protozoan parasites.
Collapse
Affiliation(s)
- S. Horjales
- Apicomplexa Biology Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay
| | - M Li Calzi
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay
| | - M. E. Francia
- Apicomplexa Biology Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - A. Cayota
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,Departmento Basico de Medicina, Facultad de Medicina, Hospital de Clinicas, Universidad de la República, Montevideo, Uruguay
| | - M. R. Garcia-Silva
- Functional Genomics Laboratory, Institute Pasteur Montevideo, Montevideo, Uruguay,*Correspondence: M. R. Garcia-Silva,
| |
Collapse
|
10
|
Li Y, Hui JHL. Small RNAs in Cnidaria: A review. Evol Appl 2023; 16:354-364. [PMID: 36793685 PMCID: PMC9923473 DOI: 10.1111/eva.13445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 05/18/2022] [Accepted: 06/17/2022] [Indexed: 11/30/2022] Open
Abstract
As fundamental components of RNA silencing, small RNA (sRNA) molecules ranging from 20 to 32 nucleotides in length have been found as potent regulators of gene expression and genome stability in many biological processes of eukaryotes. Three major small RNAs are active in animals, including the microRNA (miRNA), short interfering RNA (siRNA), and PIWI-interacting RNA (piRNA). Cnidarians, the sister group to bilaterians, are at a critical phylogenetic node to better model eukaryotic small RNA pathway evolution. To date, most of our understanding of sRNA regulation and its potential contribution to evolution has been limited to a few triploblastic bilaterian and plant models. The diploblastic nonbilaterians, including the cnidarians, are understudied in this regard. Therefore, this review will present the current-known small RNA information in cnidarians to enhance our understanding of the development of the small RNA pathways in early branch animals.
Collapse
Affiliation(s)
- Yiqian Li
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences The Chinese University of Hong Kong Hong Kong City Hong Kong
| | - Jerome H L Hui
- Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, School of Life Sciences The Chinese University of Hong Kong Hong Kong City Hong Kong
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Goh TX, Tan SL, Roebuck MM, Teo SH, Kamarul T. A systematic review of EV-piRNA in human body fluid and its role in disease progression. Tissue Eng Part C Methods 2022; 28:511-528. [PMID: 35959742 DOI: 10.1089/ten.tec.2022.0092] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The state of host cells is reflected in the cargo carried by their extracellular vesicles (EVs). This makes EV a potential source of biomarkers for human diseases. Piwi-interacting RNA (piRNA) regulates gene expression through epigenetic regulation and post-transcriptional gene silencing. Thus, piRNA profiles in EVs derived from human clinical samples could identify markers that characterize disease stages, and unveil their roles in disease pathology. This review aimed to report the expression profiles of EV-derived piRNA (EV-piRNA) in various human samples, as well as their role in each pathology. A systematic review was conducted to collate the findings of human EV-piRNA from original research articles published in indexed scientific journals up to 16th Feb 2022. Article searches were performed in PubMed, Web of Science, and Scopus databases, using a combination of keywords including 'EV' and 'piRNA'. A total of 775 non-redundant original articles were identified. After subjecting articles to inclusion and exclusion criteria, 34 articles were accepted for this review. The piRNA expression levels among the small RNA profiles of human-derived EVs range from 0.09% to 43.84%, with the lowest expression level reported in urine-derived EVs and the highest percentage in plasma-derived EVs. Differentially expressed EV-piRNAs have been identified in patients with specific disease conditions compared to their counterparts (healthy control), suggesting an association between piRNA and progression in various diseases. Seven articles identified piRNA putative target genes and/or the pathway enrichment of piRNA target genes, and one study demonstrated a direct tole of piRNA candidates in disease pathology. In conclusion, EV-piRNA has been isolated successfully from various human body fluids. EV-piRNA is a new research niche in human disease pathology. The expression profiles of EV-piRNA in various tissue types and disease conditions remain largely unexplored. Furthermore, there is currently a lack of guidelines on piRNA bioinformatics analysis, which could lead to inconsistent results and thus hinder the progression of piRNA discoveries. Lastly, the lack of published scientific evidence on the role of EV-piRNA supports the need for future research to focus on the functional analysis of EV-piRNA as part of the route in piRNA discoveries.
Collapse
Affiliation(s)
- Tuan Xin Goh
- University of Malaya Faculty of Medicine, Tissue Engineering Group (TEG), National Orthopaedic Center of Excellent Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Kuala Lumpur, Malaysia;
| | - Sik Loo Tan
- University of Malaya Faculty of Medicine, Tissue Engineering Group (TEG), National Orthopaedic Center of Excellent Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Kuala Lumpur, Malaysia;
| | - Margaret M Roebuck
- University of Liverpool Faculty of Health and Life Sciences, Department of Musculoskeletal & Ageing Science Institute of Life Course & Medical Sciences (ILCaMS) Faculty of Health & Life Sciences William Henry Duncan Building University of Liverpool, Liverpool, 6 West Derby Street Liverpool L7 8TX, United Kingdom of Great Britain and Northern Ireland;
| | - Seow-Hui Teo
- Division of Sports Injuries and Arthroscopic Surgery, National Orthopaedic Center of Excellence for Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, MALAYSIA., Division of Sports Injuries and Arthroscopic Surgery, National Orthopaedic Center of Excellence for Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Federal Territory, Kuala Lumpur, Malaysia;
| | - Tunku Kamarul
- University of Malaya Faculty of Medicine, Tissue Engineering Group (TEG), National Orthopaedic Center of Excellent Research & Learning (NOCERAL), Department of Orthopaedic Surgery, Kuala Lumpur, Wilayah Persekutuan, Malaysia;
| |
Collapse
|
13
|
Gainetdinov I, Colpan C, Cecchini K, Arif A, Jouravleva K, Albosta P, Vega-Badillo J, Lee Y, Özata DM, Zamore PD. Terminal modification, sequence, length, and PIWI-protein identity determine piRNA stability. Mol Cell 2021; 81:4826-4842.e8. [PMID: 34626567 DOI: 10.1016/j.molcel.2021.09.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 12/15/2022]
Abstract
In animals, PIWI-interacting RNAs (piRNAs) silence transposons, fight viral infections, and regulate gene expression. piRNA biogenesis concludes with 3' terminal trimming and 2'-O-methylation. Both trimming and methylation influence piRNA stability. Our biochemical data show that multiple mechanisms destabilize unmethylated mouse piRNAs, depending on whether the piRNA 5' or 3' sequence is complementary to a trigger RNA. Unlike target-directed degradation of microRNAs, complementarity-dependent destabilization of piRNAs in mice and flies is blocked by 3' terminal 2'-O-methylation and does not require base pairing to both the piRNA seed and the 3' sequence. In flies, 2'-O-methylation also protects small interfering RNAs (siRNAs) from complementarity-dependent destruction. By contrast, pre-piRNA trimming protects mouse piRNAs from a degradation pathway unaffected by trigger complementarity. In testis lysate and in vivo, internal or 3' terminal uridine- or guanine-rich tracts accelerate pre-piRNA decay. Loss of both trimming and 2'-O-methylation causes the mouse piRNA pathway to collapse, demonstrating that these modifications collaborate to stabilize piRNAs.
Collapse
Affiliation(s)
- Ildar Gainetdinov
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
| | - Cansu Colpan
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Katharine Cecchini
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Amena Arif
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Karina Jouravleva
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Paul Albosta
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Joel Vega-Badillo
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Yongjin Lee
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Deniz M Özata
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Phillip D Zamore
- RNA Therapeutics Institute and Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
| |
Collapse
|
14
|
Vogg MC, Buzgariu W, Suknovic NS, Galliot B. Cellular, Metabolic, and Developmental Dimensions of Whole-Body Regeneration in Hydra. Cold Spring Harb Perspect Biol 2021; 13:a040725. [PMID: 34230037 PMCID: PMC8635000 DOI: 10.1101/cshperspect.a040725] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Here we discuss the developmental and homeostatic conditions necessary for Hydra regeneration. Hydra is characterized by populations of adult stem cells paused in the G2 phase of the cell cycle, ready to respond to injury signals. The body column can be compared to a blastema-like structure, populated with multifunctional epithelial stem cells that show low sensitivity to proapoptotic signals, and high inducibility of autophagy that promotes resistance to stress and starvation. Intact Hydra polyps also exhibit a dynamic patterning along the oral-aboral axis under the control of homeostatic organizers whose activity results from regulatory loops between activators and inhibitors. As in bilaterians, injury triggers the immediate production of reactive oxygen species (ROS) signals that promote wound healing and contribute to the reactivation of developmental programs via cell death and the de novo formation of new organizing centers from somatic tissues. In aging Hydra, regeneration is rapidly lost as homeostatic conditions are no longer pro-regenerative.
Collapse
Affiliation(s)
- Matthias Christian Vogg
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, Geneva 4, Switzerland
| | - Wanda Buzgariu
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, Geneva 4, Switzerland
| | - Nenad Slavko Suknovic
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, Geneva 4, Switzerland
| | - Brigitte Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), Faculty of Sciences, University of Geneva, Geneva 4, Switzerland
| |
Collapse
|
15
|
Huang S, Yoshitake K, Asakawa S. A Review of Discovery Profiling of PIWI-Interacting RNAs and Their Diverse Functions in Metazoans. Int J Mol Sci 2021; 22:ijms222011166. [PMID: 34681826 PMCID: PMC8538981 DOI: 10.3390/ijms222011166] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 12/16/2022] Open
Abstract
PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs (sncRNAs) that perform crucial biological functions in metazoans and defend against transposable elements (TEs) in germ lines. Recently, ubiquitously expressed piRNAs were discovered in soma and germ lines using small RNA sequencing (sRNA-seq) in humans and animals, providing new insights into the diverse functions of piRNAs. However, the role of piRNAs has not yet been fully elucidated, and sRNA-seq studies continue to reveal different piRNA activities in the genome. In this review, we summarize a set of simplified processes for piRNA analysis in order to provide a useful guide for researchers to perform piRNA research suitable for their study objectives. These processes can help expand the functional research on piRNAs from previously reported sRNA-seq results in metazoans. Ubiquitously expressed piRNAs have been discovered in the soma and germ lines in Annelida, Cnidaria, Echinodermata, Crustacea, Arthropoda, and Mollusca, but they are limited to germ lines in Chordata. The roles of piRNAs in TE silencing, gene expression regulation, epigenetic regulation, embryonic development, immune response, and associated diseases will continue to be discovered via sRNA-seq.
Collapse
Affiliation(s)
- Songqian Huang
- Correspondence: (S.H.); (S.A.); Tel.: +81-3-5841-5296 (S.A.); Fax: +81-3-5841-8166 (S.A.)
| | | | - Shuichi Asakawa
- Correspondence: (S.H.); (S.A.); Tel.: +81-3-5841-5296 (S.A.); Fax: +81-3-5841-8166 (S.A.)
| |
Collapse
|
16
|
Gebert D, Neubert LK, Lloyd C, Gui J, Lehmann R, Teixeira FK. Large Drosophila germline piRNA clusters are evolutionarily labile and dispensable for transposon regulation. Mol Cell 2021; 81:3965-3978.e5. [PMID: 34352205 PMCID: PMC8516431 DOI: 10.1016/j.molcel.2021.07.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/23/2021] [Accepted: 07/10/2021] [Indexed: 12/13/2022]
Abstract
PIWI proteins and their guiding Piwi-interacting small RNAs (piRNAs) are crucial for fertility and transposon defense in the animal germline. In most species, the majority of piRNAs are produced from distinct large genomic loci, called piRNA clusters. It is assumed that germline-expressed piRNA clusters, particularly in Drosophila, act as principal regulators to control transposons dispersed across the genome. Here, using synteny analysis, we show that large clusters are evolutionarily labile, arise at loci characterized by recurrent chromosomal rearrangements, and are mostly species-specific across the Drosophila genus. By engineering chromosomal deletions in D. melanogaster, we demonstrate that the three largest germline clusters, which account for the accumulation of >40% of all transposon-targeting piRNAs in ovaries, are neither required for fertility nor for transposon regulation in trans. We provide further evidence that dispersed elements, rather than the regulatory action of large Drosophila germline clusters in trans, may be central for transposon defense.
Collapse
Affiliation(s)
- Daniel Gebert
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Lena K Neubert
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Catrin Lloyd
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Jinghua Gui
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Ruth Lehmann
- Howard Hughes Medical Institute (HHMI) and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
| | | |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Fujita S, Kuranaga E, Nakajima YI. Regeneration Potential of Jellyfish: Cellular Mechanisms and Molecular Insights. Genes (Basel) 2021; 12:758. [PMID: 34067753 PMCID: PMC8156412 DOI: 10.3390/genes12050758] [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: 04/21/2021] [Revised: 05/09/2021] [Accepted: 05/14/2021] [Indexed: 01/20/2023] Open
Abstract
Medusozoans, the Cnidarian subphylum, have multiple life stages including sessile polyps and free-swimming medusae or jellyfish, which are typically bell-shaped gelatinous zooplanktons that exhibit diverse morphologies. Despite having a relatively complex body structure with well-developed muscles and nervous systems, the adult medusa stage maintains a high regenerative ability that enables organ regeneration as well as whole body reconstitution from the part of the body. This remarkable regeneration potential of jellyfish has long been acknowledged in different species; however, recent studies have begun dissecting the exact processes underpinning regeneration events. In this article, we introduce the current understanding of regeneration mechanisms in medusae, particularly focusing on cellular behaviors during regeneration such as wound healing, blastema formation by stem/progenitor cells or cell fate plasticity, and the organism-level patterning that restores radial symmetry. We also discuss putative molecular mechanisms involved in regeneration processes and introduce a variety of novel model jellyfish species in the effort to understand common principles and diverse mechanisms underlying the regeneration of complex organs and the entire body.
Collapse
Affiliation(s)
- Sosuke Fujita
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan; (S.F.); (E.K.)
| | - Erina Kuranaga
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan; (S.F.); (E.K.)
| | - Yu-ichiro Nakajima
- Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Miyagi, Japan; (S.F.); (E.K.)
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8577, Miyagi, Japan
| |
Collapse
|
20
|
Pillai A, Gungi A, Reddy PC, Galande S. Epigenetic Regulation in Hydra: Conserved and Divergent Roles. Front Cell Dev Biol 2021; 9:663208. [PMID: 34041242 PMCID: PMC8141815 DOI: 10.3389/fcell.2021.663208] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022] Open
Abstract
Transitions in gene regulatory processes responsible for the emergence of specialized cell types and spatiotemporal regulation of developmental signaling prior to the divergence of Cnidaria and Bilateria are poorly understood. As a sister group of Bilateria, the phylum Cnidaria can provide significant insights into these processes. Among the cnidarians, hydrae have been studied for >250 years to comprehend the mechanisms underlying their unique immortality and robust regenerative capacity. Studies on Hydra spp. and other pre-bilaterians alike have advanced our understanding of the evolutionary underpinnings governing eumetazoan tissue development, homeostasis, and regeneration. In addition to its regenerative potential, Hydra exhibits continuously active axial patterning due to its peculiar tissue dynamics. These distinctive physiological processes necessitate large scale gene expression changes that are governed by the multitude of epigenetic mechanisms operating in cells. This review highlights the contemporary knowledge of epigenetic regulation in Hydra with contemporary studies from other members of Cnidaria, as well as the interplay between regulatory mechanisms wherever demonstrated. The studies covered in the scope of this review reveal both ancestral and divergent roles played by conserved epigenetic mechanisms with emphasis on transcriptional regulation. Additionally, single-cell transcriptomics data was mined to predict the physiological relevance of putative gene regulatory components, which is in agreement with published findings and yielded insights into the possible functions of the gene regulatory mechanisms that are yet to be deciphered in Hydra, such as DNA methylation. Finally, we delineate potentially rewarding epigenetics research avenues that can further leverage the unique biology of Hydra.
Collapse
Affiliation(s)
| | | | - Puli Chandramouli Reddy
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Sanjeev Galande
- Centre of Excellence in Epigenetics, Department of Biology, Indian Institute of Science Education and Research, Pune, India
| |
Collapse
|
21
|
Redl S, de Jesus Domingues AM, Caspani E, Möckel S, Salvenmoser W, Mendez-Lago M, Ketting RF. Extensive nuclear gyration and pervasive non-genic transcription during primordial germ cell development in zebrafish. Development 2021; 148:dev193060. [PMID: 33298460 PMCID: PMC7847270 DOI: 10.1242/dev.193060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 12/02/2021] [Indexed: 12/02/2022]
Abstract
Primordial germ cells (PGCs) are the precursors of germ cells, which migrate to the genital ridge during early development. Relatively little is known about PGCs after their migration. We studied this post-migratory stage using microscopy and sequencing techniques, and found that many PGC-specific genes, including genes known to induce PGC fate in the mouse, are only activated several days after migration. At this same time point, PGC nuclei become extremely gyrated, displaying general broad opening of chromatin and high levels of intergenic transcription. This is accompanied by changes in nuage morphology, expression of large loci (PGC-expressed non-coding RNA loci, PERLs) that are enriched for retro-transposons and piRNAs, and a rise in piRNA biogenesis signatures. Interestingly, no nuclear Piwi protein could be detected at any time point, indicating that the zebrafish piRNA pathway is fully cytoplasmic. Our data show that the post-migratory stage of zebrafish PGCs holds many cues to both germ cell fate establishment and piRNA pathway activation.
Collapse
Affiliation(s)
- Stefan Redl
- Biology of Non-coding RNA Group, Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
| | | | - Edoardo Caspani
- Biology of Non-coding RNA Group, Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, 55128 Mainz, Germany
| | - Stefanie Möckel
- Flow Cytometry Core Facility, Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - Willi Salvenmoser
- Institute of Zoology, Evolution and Developmental Biology, University of Innsbruck, Technikerstraβe 25, 6020 Innsbruck, Austria
| | - Maria Mendez-Lago
- Genomics Core Facility, Institute of Molecular Biology (IMB), Ackermannweg 4, 55128 Mainz, Germany
| | - René F Ketting
- Biology of Non-coding RNA Group, Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, 55099 Mainz, Germany
| |
Collapse
|
22
|
Xu CM, Sun SC. Expression of Piwi Genes during the Regeneration of Lineus sanguineus (Nemertea, Pilidiophora, Heteronemertea). Genes (Basel) 2020; 11:E1484. [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.
Collapse
Affiliation(s)
| | - Shi-Chun Sun
- College of Fisheries, Institute of Evolution and Marine Biodiversity, Ocean University of China, 5 Yushan Road, Qingdao 266003, China;
| |
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Wu X, Pan Y, Fang Y, Zhang J, Xie M, Yang F, Yu T, Ma P, Li W, Shu Y. The Biogenesis and Functions of piRNAs in Human Diseases. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 21:108-120. [PMID: 32516734 PMCID: PMC7283962 DOI: 10.1016/j.omtn.2020.05.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/17/2020] [Accepted: 05/18/2020] [Indexed: 02/07/2023]
Abstract
Piwi-interacting RNAs (piRNAs) are a novel type of small noncoding RNAs, which are 26-30 nt in length and bind to Piwi proteins. These short RNAs were originally discovered in germline cells and are considered as key regulators for germline maintenance. A growing body of evidence has now extended our views into piRNA biological significance showing that they can also regulate gene expression in somatic cells through transposon silencing, epigenetic programming, DNA rearrangements, mRNA turnover, and translational control. Mounting studies have revealed that the dysregulation of piRNAs may cause epigenetic changes and contribute to diverse diseases. This review illustrates piRNA biogenesis, mechanisms behind piRNA-mediated gene regulation, and changes of piRNAs in different diseases, especially in cancers.
Collapse
Affiliation(s)
- Xi Wu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Yutian Pan
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Yuan Fang
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Jingxin Zhang
- Department of General Surgery, The Affiliated People's Hospital of Jiangsu University, Zhenjiang 212002, People's Republic of China
| | - Mengyan Xie
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Fengming Yang
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Tao Yu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China
| | - Pei Ma
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China.
| | - Wei Li
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China; Department of Oncology, Affiliated Sir Run Run Hospital of Nanjing Medical University, Nanjing 211166, People's Republic of China.
| | - Yongqian Shu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, People's Republic of China; Department of Oncology, Affiliated Sir Run Run Hospital of Nanjing Medical University, Nanjing 211166, People's Republic of China; Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing 211166, People's Republic of China.
| |
Collapse
|
25
|
Teefy BB, Siebert S, Cazet JF, Lin H, Juliano CE. PIWI-piRNA pathway-mediated transposable element repression in Hydra somatic stem cells. RNA (NEW YORK, N.Y.) 2020; 26:550-563. [PMID: 32075940 PMCID: PMC7161359 DOI: 10.1261/rna.072835.119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/17/2020] [Indexed: 05/09/2023]
Abstract
Transposable elements (TEs) can damage genomes, thus organisms use a variety of mechanisms to repress TE expression. The PIWI-piRNA pathway is a small RNA pathway that represses TE expression in the germline of animals. Here we explore the function of the pathway in the somatic stem cells of Hydra, a long-lived freshwater cnidarian. Hydra have three stem cell populations, all of which express PIWI proteins; endodermal and ectodermal epithelial stem cells (ESCs) are somatic, whereas the interstitial stem cells have germline competence. To study somatic function of the pathway, we isolated piRNAs from Hydra that lack the interstitial lineage and found that these somatic piRNAs map predominantly to TE transcripts and display the conserved sequence signatures typical of germline piRNAs. Three lines of evidence suggest that the PIWI-piRNA pathway represses TEs in Hydra ESCs. First, epithelial knockdown of the Hydra piwi gene hywi resulted in up-regulation of TE expression. Second, degradome sequencing revealed evidence of PIWI-mediated cleavage of TE RNAs in epithelial cells using the ping-pong mechanism. Finally, we demonstrated a direct association between Hywi protein and TE transcripts in epithelial cells using RNA immunoprecipitation. Altogether, our data reveal that the PIWI-piRNA pathway represses TE expression in the somatic cell lineages of Hydra, which we propose contributes to the extreme longevity of the organism. Furthermore, our results, in combination with others, suggest that somatic TE repression is an ancestral function of the PIWI-piRNA pathway.
Collapse
Affiliation(s)
- Bryan B Teefy
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
| | - Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
| | - Jack F Cazet
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
| | - Haifan Lin
- Department of Cell Biology, Yale Stem Cell Center, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Celina E Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616, USA
| |
Collapse
|
26
|
Matsumoto Y, Piraino S, Miglietta MP. Transcriptome Characterization of Reverse Development in Turritopsis dohrnii (Hydrozoa, Cnidaria). G3 (BETHESDA, MD.) 2019; 9:4127-4138. [PMID: 31619459 PMCID: PMC6893190 DOI: 10.1534/g3.119.400487] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 10/08/2019] [Indexed: 02/08/2023]
Abstract
Medusae of Turritopsis dohrnii undergo reverse development in response to physical damage, adverse environmental conditions, or aging. Senescent, weakened or damaged medusae transform into a cluster of poorly differentiated cells (known as the cyst stage), which metamorphose back into a preceding life cycle stage, the polyp. During the metamorphosis, cell transdifferentiation occurs. The cyst represents the intermediate stage between a reverting medusa and a healthy polyp, during which cell transdifferentiation and tissue reorganization take place. Here we characterize and compare the transcriptomes of the polyp and newborn medusa stages of T. dohrnii with that of the cyst, to identify biological networks potentially involved in the reverse development and transdifferentiation processes. The polyp, medusa and cyst of T. dohrnii were sequenced through Illumina RNA-sequencing and assembled using a de novo approach, resulting in 92,569, 74,639 and 86,373 contigs, respectively. The transcriptomes were annotated and comparative analyses among the stages identified biological networks that were significantly over-and under-expressed in the cyst as compared to the polyp and medusa stages. Biological processes that occur at the cyst stage such as telomerase activity, regulation of transposable elements and DNA repair systems, and suppression of cell signaling pathways, mitotic cell division and cellular differentiation and development may be involved in T. dohrnii's reverse development and transdifferentiation. Our results are the first attempt to understand T. dohrnii's life-cycle reversal at the genetic level, and indicate possible avenues of future research on developmental strategies, cell transdifferentiation, and aging using T. dohrnii as a non-traditional in vivo system.
Collapse
Affiliation(s)
- Yui Matsumoto
- Texas A&M University at Galveston, Galveston, TX and
| | - Stefano Piraino
- Università del Salento, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, 73100 Lecce, Italy
| | | |
Collapse
|
27
|
Yao H, Wang X, Song J, Wang Y, Song Q, Han J. Coxsackievirus B3 infection induces changes in the expression of numerous piRNAs. Arch Virol 2019; 165:105-114. [PMID: 31741095 DOI: 10.1007/s00705-019-04451-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 09/26/2019] [Indexed: 01/02/2023]
Abstract
Piwi-interacting RNAs (piRNAs) play pivotal roles in spermatogenesis and are widely distributed among somatic tissues. However, little is known about piRNAs in HeLa cells infected with coxsackievirus B3 (CVB3). In this study, we systematically investigated changes in piRNA expression in HeLa cells infected with CVB3 using high-throughput sequencing technology. piRNA expression profiles in CVB3-infected HeLa cells were examined at 3, 6 and 9 h postinfection (pi). Of the 32,826 piRNAs that were annotated in the NCBI database, 151,571, 89,698 and 76,626 piRNAs were detected in CVB3-infected HeLa cells at 3, 6 and 9 h pi, respectively. Compared with normal cells, 211, 72 and 94 piRNAs were differentially expressed in CVB3-infected HeLa cells at 3, 6 and 9 h pi, respectively. Thirteen piRNAs, including four novel piRNAs, exhibited concurrent changes in CVB3-infected HeLa cells. The changes in the expression of these 13 piRNAs was confirmed in CVB3-infected HeLa cells and 293T cells by stem-loop RT-qPCR at 3, 6 and 9 h pi. The target genes of 13 piRNAs were predicted. The four novel piRNAs were associated with LTR/ERV, LINE/L1 and LTR/ERVK repetitive elements located on different chromosomes. These findings may promote a better understanding of the regulatory mechanism of pathophysiological changes induced by CVB3 infection.
Collapse
Affiliation(s)
- Hailan Yao
- Molecular Immunology Laboratory, Capital Institute of Pediatrics, 2 YaBao Rd, Beijing, 100020, China
| | - Xinling Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 155 Changbai Rd, Beijing, 102206, China
| | - Juan Song
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 155 Changbai Rd, Beijing, 102206, China
| | - Yanhai Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 155 Changbai Rd, Beijing, 102206, China
| | - Qinqin Song
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 155 Changbai Rd, Beijing, 102206, China
| | - Jun Han
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 155 Changbai Rd, Beijing, 102206, China.
| |
Collapse
|
28
|
Siebert S, Farrell JA, Cazet JF, Abeykoon Y, Primack AS, Schnitzler CE, Juliano CE. Stem cell differentiation trajectories in Hydra resolved at single-cell resolution. Science 2019; 365:eaav9314. [PMID: 31346039 PMCID: PMC7104783 DOI: 10.1126/science.aav9314] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/11/2019] [Indexed: 12/31/2022]
Abstract
The adult Hydra polyp continually renews all of its cells using three separate stem cell populations, but the genetic pathways enabling this homeostatic tissue maintenance are not well understood. We sequenced 24,985 Hydra single-cell transcriptomes and identified the molecular signatures of a broad spectrum of cell states, from stem cells to terminally differentiated cells. We constructed differentiation trajectories for each cell lineage and identified gene modules and putative regulators expressed along these trajectories, thus creating a comprehensive molecular map of all developmental lineages in the adult animal. In addition, we built a gene expression map of the Hydra nervous system. Our work constitutes a resource for addressing questions regarding the evolution of metazoan developmental processes and nervous system function.
Collapse
Affiliation(s)
- Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA.
| | - Jeffrey A Farrell
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Jack F Cazet
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Yashodara Abeykoon
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Abby S Primack
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience and Department of Biology, University of Florida, St. Augustine, FL, USA
| | - Celina E Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA.
| |
Collapse
|
29
|
Dimitrova DG, Teysset L, Carré C. RNA 2'-O-Methylation (Nm) Modification in Human Diseases. Genes (Basel) 2019; 10:E117. [PMID: 30764532 PMCID: PMC6409641 DOI: 10.3390/genes10020117] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 12/24/2022] Open
Abstract
Nm (2'-O-methylation) is one of the most common modifications in the RNA world. It has the potential to influence the RNA molecules in multiple ways, such as structure, stability, and interactions, and to play a role in various cellular processes from epigenetic gene regulation, through translation to self versus non-self recognition. Yet, building scientific knowledge on the Nm matter has been hampered for a long time by the challenges in detecting and mapping this modification. Today, with the latest advancements in the area, more and more Nm sites are discovered on RNAs (tRNA, rRNA, mRNA, and small non-coding RNA) and linked to normal or pathological conditions. This review aims to synthesize the Nm-associated human diseases known to date and to tackle potential indirect links to some other biological defects.
Collapse
Affiliation(s)
- Dilyana G Dimitrova
- Sorbonne Université, Institut de Biologie Paris Seine, Centre National de la Recherche Scientifique, Transgenerational Epigenetics & Small RNA Biology, Laboratoire de Biologie du Développement, 75005 Paris, France.
| | - Laure Teysset
- Sorbonne Université, Institut de Biologie Paris Seine, Centre National de la Recherche Scientifique, Transgenerational Epigenetics & Small RNA Biology, Laboratoire de Biologie du Développement, 75005 Paris, France.
| | - Clément Carré
- Sorbonne Université, Institut de Biologie Paris Seine, Centre National de la Recherche Scientifique, Transgenerational Epigenetics & Small RNA Biology, Laboratoire de Biologie du Développement, 75005 Paris, France.
| |
Collapse
|
30
|
Czech B, Munafò M, Ciabrelli F, Eastwood EL, Fabry MH, Kneuss E, Hannon GJ. piRNA-Guided Genome Defense: From Biogenesis to Silencing. Annu Rev Genet 2018; 52:131-157. [PMID: 30476449 PMCID: PMC10784713 DOI: 10.1146/annurev-genet-120417-031441] [Citation(s) in RCA: 302] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
PIWI-interacting RNAs (piRNAs) and their associated PIWI clade Argonaute proteins constitute the core of the piRNA pathway. In gonadal cells, this conserved pathway is crucial for genome defense, and its main function is to silence transposable elements. This is achieved through posttranscriptional and transcriptional gene silencing. Precursors that give rise to piRNAs require specialized transcription and transport machineries because piRNA biogenesis is a cytoplasmic process. The ping-pong cycle, a posttranscriptional silencing mechanism, combines the cleavage-dependent silencing of transposon RNAs with piRNA production. PIWI proteins also function in the nucleus, where they scan for nascent target transcripts with sequence complementarity, instructing transcriptional silencing and deposition of repressive chromatin marks at transposon loci. Although studies have revealed numerous factors that participate in each branch of the piRNA pathway, the precise molecular roles of these factors often remain unclear. In this review, we summarize our current understanding of the mechanisms involved in piRNA biogenesis and function.
Collapse
Affiliation(s)
- Benjamin Czech
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Marzia Munafò
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Filippo Ciabrelli
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Evelyn L Eastwood
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Martin H Fabry
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Emma Kneuss
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| | - Gregory J Hannon
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge CB2 0RE, United Kingdom; ,
| |
Collapse
|
31
|
Ramos-Vicente D, Ji J, Gratacòs-Batlle E, Gou G, Reig-Viader R, Luís J, Burguera D, Navas-Perez E, García-Fernández J, Fuentes-Prior P, Escriva H, Roher N, Soto D, Bayés À. Metazoan evolution of glutamate receptors reveals unreported phylogenetic groups and divergent lineage-specific events. eLife 2018; 7:e35774. [PMID: 30465522 PMCID: PMC6307864 DOI: 10.7554/elife.35774] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 11/20/2018] [Indexed: 01/28/2023] Open
Abstract
Glutamate receptors are divided in two unrelated families: ionotropic (iGluR), driving synaptic transmission, and metabotropic (mGluR), which modulate synaptic strength. The present classification of GluRs is based on vertebrate proteins and has remained unchanged for over two decades. Here we report an exhaustive phylogenetic study of GluRs in metazoans. Importantly, we demonstrate that GluRs have followed different evolutionary histories in separated animal lineages. Our analysis reveals that the present organization of iGluRs into six classes does not capture the full complexity of their evolution. Instead, we propose an organization into four subfamilies and ten classes, four of which have never been previously described. Furthermore, we report a sister class to mGluR classes I-III, class IV. We show that many unreported proteins are expressed in the nervous system, and that new Epsilon receptors form functional ligand-gated ion channels. We propose an updated classification of glutamate receptors that includes our findings.
Collapse
Affiliation(s)
- David Ramos-Vicente
- Molecular Physiology of the Synapse LaboratoryBiomedical Research Institute Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
| | - Jie Ji
- Institute of Biotechnology and Biomedicine, Department of Cell Biology, Animal Physiology and ImmunologyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Esther Gratacòs-Batlle
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, August Pi i Sunyer Biomedical Research Institute, Institute of NeurosciencesUniversitat de BarcelonaBarcelonaSpain
| | - Gemma Gou
- Molecular Physiology of the Synapse LaboratoryBiomedical Research Institute Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
| | - Rita Reig-Viader
- Molecular Physiology of the Synapse LaboratoryBiomedical Research Institute Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
| | - Javier Luís
- Molecular Physiology of the Synapse LaboratoryBiomedical Research Institute Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
| | - Demian Burguera
- Department of Genetics, School of Biology, Institut de BiomedicinaUniversity of BarcelonaBarcelonaSpain
| | - Enrique Navas-Perez
- Department of Genetics, School of Biology, Institut de BiomedicinaUniversity of BarcelonaBarcelonaSpain
| | - Jordi García-Fernández
- Department of Genetics, School of Biology, Institut de BiomedicinaUniversity of BarcelonaBarcelonaSpain
| | - Pablo Fuentes-Prior
- Molecular Bases of DiseaseBiomedical Research Institute Sant Pau, Hospital de la Santa Creu i Sant PauBarcelonaSpain
| | - Hector Escriva
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes MarinsBanyuls-sur-MerFrance
| | - Nerea Roher
- Institute of Biotechnology and Biomedicine, Department of Cell Biology, Animal Physiology and ImmunologyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - David Soto
- Neurophysiology Laboratory, Department of Biomedicine, Medical School, August Pi i Sunyer Biomedical Research Institute, Institute of NeurosciencesUniversitat de BarcelonaBarcelonaSpain
| | - Àlex Bayés
- Molecular Physiology of the Synapse LaboratoryBiomedical Research Institute Sant PauBarcelonaSpain
- Universitat Autònoma de BarcelonaBarcelonaSpain
| |
Collapse
|
32
|
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.
Collapse
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
| |
Collapse
|
33
|
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.
Collapse
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.
| |
Collapse
|
34
|
Russell SJ, Stalker L, LaMarre J. PIWIs, piRNAs and Retrotransposons: Complex battles during reprogramming in gametes and early embryos. Reprod Domest Anim 2018; 52 Suppl 4:28-38. [PMID: 29052331 DOI: 10.1111/rda.13053] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Gamete and embryo development are indispensable processes for successful reproduction. Cells involved in these processes acquire pluripotency, the ability to differentiate into multiple different cell types, through a series of events known as reprogramming that lead to profound changes in histone and DNA methylation. While essential for pluripotency, this epigenetic remodelling removes constraints that normally limit the expression of genomic sequences known as transposable elements (TEs). Unconstrained TE expression can lead to many deleterious consequences including infertility, so organisms have evolved complex and potent mechanistic arsenals to target and suppress TE expression during reprogramming. This review will focus on the control of transposable elements in gametes and embryos, and one important TE suppressing system known as the PIWI pathway. This broadly conserved, small RNA-targeted silencing mechanism appears critical for fertility in many species and may participate in multiple aspects of gene regulation in reproduction and other contexts.
Collapse
Affiliation(s)
- S J Russell
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - L Stalker
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - J LaMarre
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
35
|
Abstract
In bilaterian animals the 3′ ends of microRNAs (miRNAs) are frequently modified by tailing and trimming. These modifications affect miRNA-mediated gene regulation by modulating miRNA stability. Here, we analyzed data from three nonbilaterian animals: two cnidarians (Nematostella vectensis and Hydra magnipapillata) and one poriferan (Amphimedon queenslandica). Our analysis revealed that nonbilaterian miRNAs frequently undergo modifications like the bilaterian counterparts: the majority are expressed as different length isoforms and frequent modifications of the 3′ end by mono U or mono A tailing are observed. Moreover, as the factors regulating miRNA modifications are largely uncharacterized in nonbilaterian animal phyla, in present study, we investigated the evolution of 3′ terminal uridylyl transferases (TUTases) that are known to involved in miRNA 3′ nontemplated modifications in Bilateria. Phylogenetic analysis on TUTases showed that TUTase1 and TUTase6 are a result of duplication in bilaterians and that TUTase7 and TUTase4 are the result of a vertebrate-specific duplication. We also find an unexpected number of Drosophila-specific gene duplications and domain losses in most of the investigated gene families. Overall, our findings shed new light on the evolutionary history of TUTases in Metazoa, as they reveal that this core set of enzymes already existed in the last common ancestor of all animals and was probably involved in modifying small RNAs in a similar fashion to its present activity in bilaterians.
Collapse
Affiliation(s)
- Vengamanaidu Modepalli
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
36
|
Wang H, Wang B, Liu J, Li A, Zhu H, Wang X, Zhang Q. Piwil1 gene is regulated by hypothalamic-pituitary-gonadal axis in turbot (Scophthalmus maximus): A different effect in ovaries and testes. Gene 2018. [PMID: 29524575 DOI: 10.1016/j.gene.2018.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As constituent factors of Piwi-interacting RNA (piRNA) pathways, Piwi proteins are essential for germline maintenance and gonadal development. Previous studies show that Piwi-piRNA pathways could be regulated by hypothalamic-pituitary-gonadal (HPG) axis, however, related studies have not been reported in marine species. Here we reported the identification of turbot (Scophthalmus maximus) piwil1 gene, which was abundantly expressed in testis and ovary in a tissue-specific manner. Phylogenetic and genomic structure analyses revealed that piwil1 was conserved in its sequence and function during vertebrate evolution. We also investigated the effects of HPG axis hormones, including human chorionic gonadotropin (hCG), estradiol-17β (E2) and 17α-methyltestosterone (MT), on gonadal piwil1 expression via in vivo and in vitro approaches. In ovary, hCG and E2 suppressed piwil1 expression both in vivo and in vitro, and MT increased piwil1 expression in vivo. In testis, hCG had upregulating effects on piwil1 expression in vivo and in vitro, and MT also increased piwil1 expression in vitro. In addition, E2 suppressed expression of piwil1 in vivo. These results indicated that the decreased or increased expression of piwil1 regulated by hormones might play a crucial role during gonadal differentiation and development in S. maximus.
Collapse
Affiliation(s)
- Huizhen Wang
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China
| | - Bo Wang
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China
| | - Jinxiang Liu
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China
| | - Aoyun Li
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China
| | - He Zhu
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China
| | - XuBo Wang
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China.
| | - Quanqi Zhang
- Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, 266003, Qingdao, Shandong, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, 266237, Qingdao, Shandong, China.
| |
Collapse
|
37
|
Lai AG, Aboobaker AA. EvoRegen in animals: Time to uncover deep conservation or convergence of adult stem cell evolution and regenerative processes. Dev Biol 2018; 433:118-131. [PMID: 29198565 DOI: 10.1016/j.ydbio.2017.10.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 01/08/2023]
Abstract
How do animals regenerate specialised tissues or their entire body after a traumatic injury, how has this ability evolved and what are the genetic and cellular components underpinning this remarkable feat? While some progress has been made in understanding mechanisms, relatively little is known about the evolution of regenerative ability. Which elements of regeneration are due to lineage specific evolutionary novelties or have deeply conserved roots within the Metazoa remains an open question. The renaissance in regeneration research, fuelled by the development of modern functional and comparative genomics, now enable us to gain a detailed understanding of both the mechanisms and evolutionary forces underpinning regeneration in diverse animal phyla. Here we review existing and emerging model systems, with the focus on invertebrates, for studying regeneration. We summarize findings across these taxa that tell us something about the evolution of adult stem cell types that fuel regeneration and the growing evidence that many highly regenerative animals harbor adult stem cells with a gene expression profile that overlaps with germline stem cells. We propose a framework in which regenerative ability broadly evolves through changes in the extent to which stem cells generated through embryogenesis are maintained into the adult life history.
Collapse
Affiliation(s)
- Alvina G Lai
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - A Aziz Aboobaker
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
| |
Collapse
|
38
|
Wang W, Ashby R, Ying H, Maleszka R, Forêt S. Contrasting Sex-and Caste-Dependent piRNA Profiles in the Transposon Depleted Haplodiploid Honeybee Apis mellifera. Genome Biol Evol 2018; 9:1341-1356. [PMID: 28472327 PMCID: PMC5452642 DOI: 10.1093/gbe/evx087] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2017] [Indexed: 12/12/2022] Open
Abstract
Protecting genome integrity against transposable elements is achieved by intricate molecular mechanisms involving PIWI proteins, their associated small RNAs (piRNAs), and epigenetic modifiers such as DNA methylation. Eusocial bees, in particular the Western honeybee, Apis mellifera, have one of the lowest contents of transposable elements in the animal kingdom, and, unlike other animals with a functional DNA methylation system, appear not to methylate their transposons. This raises the question of whether the PIWI machinery has been retained in this species. Using comparative genomics, mass spectrometry, and expressional profiling, we present seminal evidence that the piRNA system is conserved in honeybees. We show that honey bee piRNAs contain a 2'-O-methyl modification at the 3' end, and have a bias towards a 5' terminal U, which are signature features of their biogenesis. Both piRNA repertoire and expression levels are greater in reproductive individuals than in sterile workers. Haploid males, where the detrimental effects of transposons are dominant, have the greatest piRNA levels, but surprisingly, the highest expression of transposons. These results show that even in a transposon-depleted species, the piRNA system is required to guard the vulnerable haploid genome and reproductive castes against transposon-associated genomic instability. This also suggests that dosage plays an important role in the regulation of transposons and piRNAs expression in haplo-diploid systems.
Collapse
Affiliation(s)
- Weiwen Wang
- Research School of Biology, Australian National University, Acton, ACT, Australia
| | - Regan Ashby
- Research School of Biology, Australian National University, Acton, ACT, Australia.,Centre for Research in Therapeutic Solutions, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, ACT, Australia
| | - Hua Ying
- Research School of Biology, Australian National University, Acton, ACT, Australia
| | - Ryszard Maleszka
- Research School of Biology, Australian National University, Acton, ACT, Australia
| | - Sylvain Forêt
- Research School of Biology, Australian National University, Acton, ACT, Australia.,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| |
Collapse
|
39
|
Roles of Germline Stem Cells and Somatic Multipotent Stem Cells in Hydra Sexual Reproduction. DIVERSITY AND COMMONALITY IN ANIMALS 2018. [DOI: 10.1007/978-4-431-56609-0_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
40
|
Praher D, Zimmermann B, Genikhovich G, Columbus-Shenkar Y, Modepalli V, Aharoni R, Moran Y, Technau U. Characterization of the piRNA pathway during development of the sea anemone Nematostella vectensis. RNA Biol 2017; 14:1727-1741. [PMID: 28783426 PMCID: PMC5731801 DOI: 10.1080/15476286.2017.1349048] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
PIWI-interacting RNAs (piRNAs) and associated proteins comprise a conserved pathway for silencing transposons in metazoan germlines. piRNA pathway components are also expressed in multipotent somatic stem cells in various organisms. piRNA functions have been extensively explored in bilaterian model systems, however, comprehensive studies in non-bilaterian phyla remain limited. Here we investigate the piRNA pathway during the development of Nematostella vectensis, a well-established model system belonging to Cnidaria, the sister group to Bilateria. To date, no population of somatic stem cells has been identified in this organism, despite its long life-span and regenerative capacities that require a constant cell-renewal. We show that Nematostella piRNA pathway components are broadly expressed in early developmental stages, while piRNAs themselves show differential expression, suggesting specific developmental roles of distinct piRNA families. In adults, piRNA associated proteins are enriched in the germline but also expressed in somatic cells, indicating putative stem cell properties. Furthermore, we provide experimental evidence that Nematostella piRNAs cleave transposable elements as well as protein-coding genes. Our results demonstrate that somatic expression of piRNA associated proteins as well as the roles of piRNAs in transposon repression and gene regulation are likely ancestral features that evolved before the split between Cnidaria and Bilateria.
Collapse
Affiliation(s)
- Daniela Praher
- Department of Molecular Evolution and Development; Centre of Organismal Systems Biology, Faculty of Life Sciences, University of Vienna; Althanstrasse 14, Wien, Austria
| | - Bob Zimmermann
- Department of Molecular Evolution and Development; Centre of Organismal Systems Biology, Faculty of Life Sciences, University of Vienna; Althanstrasse 14, Wien, Austria
| | - Grigory Genikhovich
- Department of Molecular Evolution and Development; Centre of Organismal Systems Biology, Faculty of Life Sciences, University of Vienna; Althanstrasse 14, Wien, Austria
| | - Yaara Columbus-Shenkar
- Department of Ecology, Evolution and Behavior; Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem; Givat Ram, Jerusalem, Israel
| | - Vengamanaidu Modepalli
- Department of Ecology, Evolution and Behavior; Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem; Givat Ram, Jerusalem, Israel
| | - Reuven Aharoni
- Department of Ecology, Evolution and Behavior; Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem; Givat Ram, Jerusalem, Israel
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior; Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem; Givat Ram, Jerusalem, Israel
| | - Ulrich Technau
- Department of Molecular Evolution and Development; Centre of Organismal Systems Biology, Faculty of Life Sciences, University of Vienna; Althanstrasse 14, Wien, Austria
| |
Collapse
|
41
|
Sakakibara K, Siomi MC. The PIWI-Interacting RNA Molecular Pathway: Insights From Cultured Silkworm Germline Cells. Bioessays 2017; 40. [DOI: 10.1002/bies.201700068] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/26/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Kazuhiro Sakakibara
- Department of Biological Sciences; Graduate School of Science; The University of Tokyo; Tokyo 113-0032 Japan
| | - Mikiko C. Siomi
- Department of Biological Sciences; Graduate School of Science; The University of Tokyo; Tokyo 113-0032 Japan
| |
Collapse
|
42
|
Huang X, Fejes Tóth K, Aravin AA. piRNA Biogenesis in Drosophila melanogaster. Trends Genet 2017; 33:882-894. [PMID: 28964526 DOI: 10.1016/j.tig.2017.09.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022]
Abstract
The PIWI-interacting RNA (piRNA) pathway is a conserved defense system that protects the genome integrity of the animal germline from deleterious transposable elements. Targets of silencing are recognized by small noncoding piRNAs that are processed from long precursor molecules. Although piRNAs and other classes of small noncoding RNAs, such as miRNAs and small interfering (si)RNAs, interact with members of the same family of Argonaute (Ago) proteins and their function in target repression is similar, the biogenesis of piRNAs differs from those of the other two small RNAs. Recently, many aspects of piRNA biogenesis have been revealed in Drosophila melanogaster. In this review, we elaborate on piRNA biogenesis in Drosophila somatic and germline cells. We focus on the mechanisms by which piRNA precursor transcription is regulated and highlight recent work that has advanced our understanding of piRNA precursor processing to mature piRNAs. We finish by discussing current models to the still unresolved question of how piRNA precursors are selected and channeled into the processing machinery.
Collapse
Affiliation(s)
- Xiawei Huang
- California Institute of Technology, Division of Biology and Biological Engineering, 147-75, 1200 E. California Boulevard, Pasadena, CA 91125, USA
| | - Katalin Fejes Tóth
- California Institute of Technology, Division of Biology and Biological Engineering, 147-75, 1200 E. California Boulevard, Pasadena, CA 91125, USA.
| | - Alexei A Aravin
- California Institute of Technology, Division of Biology and Biological Engineering, 147-75, 1200 E. California Boulevard, Pasadena, CA 91125, USA.
| |
Collapse
|
43
|
Sahu S, Dattani A, Aboobaker AA. Secrets from immortal worms: What can we learn about biological ageing from the planarian model system? Semin Cell Dev Biol 2017; 70:108-121. [PMID: 28818620 DOI: 10.1016/j.semcdb.2017.08.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/07/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022]
Abstract
Understanding how some animals are immortal and avoid the ageing process is important. We currently know very little about how they achieve this. Research with genetic model systems has revealed the existence of conserved genetic pathways and molecular processes that affect longevity. Most of these established model organisms have relatively short lifespans. Here we consider the use of planarians, with an immortal life-history that is able to entirely avoid the ageing process. These animals are capable of profound feats of regeneration fueled by a population of adult stem cells called neoblasts. These cells are capable of indefinite self-renewal that has underpinned the evolution of animals that reproduce only by fission, having disposed of the germline, and must therefore be somatically immortal and avoid the ageing process. How they do this is only now starting to be understood. Here we suggest that the evidence so far supports the hypothesis that the lack of ageing is an emergent property of both being highly regenerative and the evolution of highly effective mechanisms for ensuring genome stability in the neoblast stem cell population. The details of these mechanisms could prove to be very informative in understanding how the causes of ageing can be avoided, slowed or even reversed.
Collapse
Affiliation(s)
- Sounak Sahu
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - Anish Dattani
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - A Aziz Aboobaker
- Department of Zoology, South Parks Road, University of Oxford, Oxford OX1 3PS, UK.
| |
Collapse
|
44
|
Wang H, Wang B, Liu X, Liu Y, Du X, Zhang Q, Wang X. Identification and expression of piwil2 in turbot Scophthalmus maximus, with implications of the involvement in embryonic and gonadal development. Comp Biochem Physiol B Biochem Mol Biol 2017; 208-209:84-93. [PMID: 28438683 DOI: 10.1016/j.cbpb.2017.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/07/2017] [Accepted: 04/17/2017] [Indexed: 11/17/2022]
Abstract
Piwil2, a member of the Argonaute family, is involved in the biogenesis of PIWI-interacting RNAs (piRNAs) and plays an important role in regulating gametogenesis. In the present study, we identified turbot Scophthalmus maximus piwil2 gene, named Smpiwil2, which contained a PAZ domain and a PIWI domain. Sequence comparison, genomic structure and phylogenetic analyses showed that Smpiwil2 is homologous to that of teleosts and tetrapods. The Smpiwil2 transcript showed higher expression in the ovary than in the testis, demonstrating a sexually dimorphic gene expression pattern. In situ hybridization (ISH) showed that Smpiwil2 was expressed in the oogonia and all the stages of oocytes in the ovary as well as in spermatogonia and spermatocytes in the testis. Embryonic expression profile revealed that Smpiwil2 was maternally inherited, and its level was higher from the zygote to the blastula stage and subsequently decreased until hatching. Moreover, a CpG island was predicted to locate in the 5'-flanking region of Smpiwil2 gene, and its methylation levels detected by sodium bisulfite sequencing showed significant disparity between females and males, implying that the sexually dimorphic expression of Smpiwil2 might be regulated by methylation. These results indicated that Smpiwil2 had potentially vital functions in embryonic and gonadal development in this species. In addition, the temporal and sex differences in Smpiwil2 expression indicated that this gene may play different roles in gonadal development of different sexes.
Collapse
Affiliation(s)
- Huizhen Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - Bo Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - Xiaobing Liu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - Yuezhong Liu
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - Xinxin Du
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - Quanqi Zhang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China
| | - XuBo Wang
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, 266003 Qingdao, Shandong, China.
| |
Collapse
|
45
|
Russell SJ, Stalker L, Gilchrist G, Backx A, Molledo G, Foster RA, LaMarre J. Identification of PIWIL1 Isoforms and Their Expression in Bovine Testes, Oocytes, and Early Embryos. Biol Reprod 2016; 94:75. [PMID: 26911426 DOI: 10.1095/biolreprod.115.136721] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/11/2016] [Indexed: 12/21/2022] Open
Abstract
PIWI proteins are members of the larger Argonaute family and bind to specific 24-32 nucleotide RNAs called PIWI-interacting RNAs (piRNAs). PIWI-interacting RNAs direct PIWI-mediated suppression of retrotransposon expression in the male germline in humans and mice, but their roles in bovine reproduction and embryogenesis are unknown. Although the majority of research in mammals has focused on the functions of PIWI proteins during spermatogenesis, this family of proteins and their associated piRNAs have recently been identified in early embryos. The goals of this study were to characterize the expression of PIWIL1 in bovine testis, oocytes, and early embryos. A full-lengthPIWIL1transcript and protein was found in the testis, specifically in the germs cells of mature seminiferous tubules. RNA-immunoprecipitation demonstrated the presence of putative piRNAs with a mean length of 30 nucleotides bound to PIWIL1 in testes. 3'-Rapid amplification of cDNA ends analysis ofPIWIL1transcripts in testes and oocytes revealed two shorter isoforms in addition to the full-length transcript that was only present in testes. TruncatedPIWIL1isoforms in oocytes and testes were confirmed through amplification of their unique intronic fragments. Expression profiling ofPIWIL1through early embryogenesis demonstrated peak mRNA expression at the 2-cell stage with decreasing levels through to the blastocyst. PIWIL1-YFP fusion plasmids were produced for each isoform and expressed in HEK 293 cells, demonstrating nuclear exclusion and size-specific banding of the different isoforms. These data represent the first comprehensive characterization of PIWIL1 in bovine, revealing functional similarities with PIWIL1 in other species and suggest tissue-specific expression of several isoforms.
Collapse
Affiliation(s)
- Stewart J Russell
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Leanne Stalker
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Graham Gilchrist
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Alanna Backx
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Gonzalo Molledo
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Robert A Foster
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Jonathan LaMarre
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
46
|
Abstract
The evolution of multicellular animals has been attributed to many kinds of selective advantage; here I suggest that the evolution of somatic cells to feed and protect the germline was central to the appearance of animals. This would have been driven by selection for extreme anisogamy--the evolution of sperm and egg. Evidence is adduced from the germline stem cells of simple animals (defining germline as any cell that normally produces the next generation via the sexual process) and from the control circuitry ubiquitous in animal germlines. With the soma and its elaboration came animal development, as we understand it.
Collapse
Affiliation(s)
- Hugh R Woodland
- School of Life Sciences, University of Warwick, Coventry, United Kingdom.
| |
Collapse
|
47
|
Abstract
Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration.
Collapse
Affiliation(s)
- Florence Marlow
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY, 10461, USA; Department of Neuroscience, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY, 10461, USA
| |
Collapse
|
48
|
Abstract
Stem cells are pivotal for development and tissue homeostasis of multicellular animals, and the quest for a gene toolkit associated with the emergence of stem cells in a common ancestor of all metazoans remains a major challenge for evolutionary biology. We reconstructed the conserved gene repertoire of animal stem cells by transcriptomic profiling of totipotent archeocytes in the demosponge Ephydatia fluviatilis and by tracing shared molecular signatures with flatworm and Hydra stem cells. Phylostratigraphy analyses indicated that most of these stem-cell genes predate animal origin, with only few metazoan innovations, notably including several partners of the Piwi machinery known to promote genome stability. The ancestral stem-cell transcriptome is strikingly poor in transcription factors. Instead, it is rich in RNA regulatory actors, including components of the "germ-line multipotency program" and many RNA-binding proteins known as critical regulators of mammalian embryonic stem cells.
Collapse
|
49
|
Epigenetics and Shared Molecular Processes in the Regeneration of Complex Structures. Stem Cells Int 2015; 2016:6947395. [PMID: 26681954 PMCID: PMC4670690 DOI: 10.1155/2016/6947395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/30/2015] [Indexed: 12/27/2022] Open
Abstract
The ability to regenerate complex structures is broadly represented in both plant and animal kingdoms. Although regenerative abilities vary significantly amongst metazoans, cumulative studies have identified cellular events that are broadly observed during regenerative events. For example, structural damage is recognized and wound healing initiated upon injury, which is followed by programmed cell death in the vicinity of damaged tissue and a burst in proliferation of progenitor cells. Sustained proliferation and localization of progenitor cells to site of injury give rise to an assembly of differentiating cells known as the regeneration blastema, which fosters the development of new tissue. Finally, preexisting tissue rearranges and integrates with newly differentiated cells to restore proportionality and function. While heterogeneity exists in the basic processes displayed during regenerative events in different species—most notably the cellular source contributing to formation of new tissue—activation of conserved molecular pathways is imperative for proper regulation of cells during regeneration. Perhaps the most fundamental of such molecular processes entails chromatin rearrangements, which prime large changes in gene expression required for differentiation and/or dedifferentiation of progenitor cells. This review provides an overview of known contributions to regenerative processes by noncoding RNAs and chromatin-modifying enzymes involved in epigenetic regulation.
Collapse
|
50
|
Lim RSM, Kai T. A piece of the pi(e): The diverse roles of animal piRNAs and their PIWI partners. Semin Cell Dev Biol 2015; 47-48:17-31. [PMID: 26582251 DOI: 10.1016/j.semcdb.2015.10.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Small non-coding RNAs are indispensable to many biological processes. A class of endogenous small RNAs, termed PIWI-interacting RNAs (piRNAs) because of their association with PIWI proteins, has known roles in safeguarding the genome against inordinate transposon mobilization, embryonic development, and stem cell regulation, among others. This review discusses the biogenesis of animal piRNAs and their diverse functions together with their PIWI protein partners, both in the germline and in somatic cells, and highlights the evolutionarily conserved aspects of these molecular players in animal biology.
Collapse
Affiliation(s)
- Robyn S M Lim
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| | - Toshie Kai
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| |
Collapse
|