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Scarpa A, Kofler R. The impact of paramutations on the invasion dynamics of transposable elements. Genetics 2023; 225:iyad181. [PMID: 37819004 PMCID: PMC10697812 DOI: 10.1093/genetics/iyad181] [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: 07/14/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/13/2023] Open
Abstract
According to the prevailing view, the trap model, the activity of invading transposable elements (TEs) is greatly reduced when a TE copy jumps into a piRNA cluster, which triggers the emergence of piRNAs that silence the TE. One crucial component in the host defence are paramutations. Mediated by maternally deposited piRNAs, paramutations convert TE insertions into piRNA producing loci, thereby transforming selfish TEs into agents of the host defence. Despite this significant effect, the impact of paramutations on the dynamics of TE invasions remains unknown. To address this issue, we performed extensive forward simulations of TE invasions with piRNA clusters and paramutations. We found that paramutations significantly affect TE dynamics, by accelerating the silencing of TE invasions, reducing the number of insertions accumulating during the invasions and mitigating the fitness cost of TEs. We also demonstrate that piRNA production induced by paramutations, an epigenetically inherited trait, may be positively selected. Finally, we show that paramutations may account for three important open problems with the trap model. Firstly, paramutated TE insertions may compensate for the insufficient number of insertions in piRNA clusters observed in previous studies. Secondly, paramutations may explain the discrepancy between the observed and the expected abundance of different TE families in Drosophila melanogaster. Thirdly, piRNA clusters may be crucial to trigger the host defence, but paramutations render the clusters dispensable once the defence has been established. This could account for the lack of TE activation when three major piRNA clusters were deleted in a previous study.
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Affiliation(s)
- Almorò Scarpa
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, Wien 1210, Austria
- Vienna Graduate School of Population Genetics, Vetmeduni Vienna, Vienna, Austria
| | - Robert Kofler
- Institut für Populationsgenetik, Vetmeduni Vienna, Veterinärplatz 1, Wien 1210, Austria
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Fukui T, Shoji K, Kiuchi T, Suzuki Y, Katsuma S. Masculinizer is not post-transcriptionally regulated by female-specific piRNAs during sex determination in the Asian corn borer, Ostrinia furnacalis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 156:103946. [PMID: 37075905 DOI: 10.1016/j.ibmb.2023.103946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/31/2023] [Accepted: 04/16/2023] [Indexed: 05/03/2023]
Abstract
Lepidopteran insects are heterogametic in females, although most insect species are heterogametic in males. In a lepidopteran model species, the silkworm Bombyx mori (Bombycoidea), the uppermost sex determinant Feminizer (Fem) has been identified on the female-specific W chromosome. Fem is a precursor of PIWI-interacting small RNA (piRNA). Fem piRNA forms a complex with Siwi, one of the two B. mori PIWI-clade Argonaute proteins. In female embryos, Fem piRNA-Siwi complex cleaves the mRNA of the male-determining gene Masculinizer (Masc), directing the female-determining pathway. In male embryos, Masc activates the male-determining pathway in the absence of Fem piRNA. Recently, W chromosome-derived piRNAs complementary to Masc mRNA have also been identified in the diamondback moth Plutella xylostella (Yponomeutoidea), indicating the convergent evolution of piRNA-dependent sex determination in Lepidoptera. Here, we show that this is not the case in the Asian corn borer, Ostrinia furnacalis (Pyraloidea). Although our previous studies demonstrated that O. furnacalis Masc (OfMasc) has a masculinizing function in the embryonic stage, the expression level of OfMasc was indistinguishable between the sexes at the timing of sex determination. Deep sequencing analysis identified no female-specific small RNAs mapped onto OfMasc mRNA. Embryonic knockdown of two PIWI genes did not affect the expression level of OfMasc in either sex. These results demonstrated that piRNA-dependent reduction of Masc mRNA in female embryos is not a common strategy of sex determination, which suggests the possibility of divergent evolution of sex determinants across the order Lepidoptera.
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Affiliation(s)
- Takahiro Fukui
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Keisuke Shoji
- Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Santos D, Feng M, Kolliopoulou A, Taning CNT, Sun J, Swevers L. What Are the Functional Roles of Piwi Proteins and piRNAs in Insects? INSECTS 2023; 14:insects14020187. [PMID: 36835756 PMCID: PMC9962485 DOI: 10.3390/insects14020187] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/09/2023] [Accepted: 02/11/2023] [Indexed: 06/01/2023]
Abstract
Research on Piwi proteins and piRNAs in insects has focused on three experimental models: oogenesis and spermatogenesis in Drosophila melanogaster, the antiviral response in Aedes mosquitoes and the molecular analysis of primary and secondary piRNA biogenesis in Bombyx mori-derived BmN4 cells. Significant unique and complementary information has been acquired and has led to a greater appreciation of the complexity of piRNA biogenesis and Piwi protein function. Studies performed in other insect species are emerging and promise to add to the current state of the art on the roles of piRNAs and Piwi proteins. Although the primary role of the piRNA pathway is genome defense against transposons, particularly in the germline, recent findings also indicate an expansion of its functions. In this review, an extensive overview is presented of the knowledge of the piRNA pathway that so far has accumulated in insects. Following a presentation of the three major models, data from other insects were also discussed. Finally, the mechanisms for the expansion of the function of the piRNA pathway from transposon control to gene regulation were considered.
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Affiliation(s)
- Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, Division of Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Anna Kolliopoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
| | - Clauvis N. T. Taning
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, National Centre for Scientific Research “Demokritos”, Aghia Paraskevi, 15341 Athens, Greece
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Shoji K, Umemura Y, Katsuma S, Tomari Y. The piRNA cluster torimochi is an expanding transposon in cultured silkworm cells. PLoS Genet 2023; 19:e1010632. [PMID: 36758066 PMCID: PMC9946225 DOI: 10.1371/journal.pgen.1010632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/22/2023] [Accepted: 01/20/2023] [Indexed: 02/11/2023] Open
Abstract
PIWI proteins and PIWI-interacting RNAs (piRNAs) play a central role in repressing transposable elements in animal germ cells. It is thought that piRNAs are mainly produced from discrete genomic loci named piRNA clusters, which often contain many "dead" transposon remnants from past invasions and have heterochromatic features. In the genome of silkworm ovary-derived cultured cells called BmN4, a well-established model for piRNA research, torimochi was previously annotated as a unique and specialized genomic region that can capture transgenes and produce new piRNAs bearing a trans-silencing activity. However, the sequence identity of torimochi has remained elusive. Here, we carefully characterized torimochi by utilizing the updated silkworm genome sequence and the long-read sequencer MinION. We found that torimochi is in fact a full-length gypsy-like LTR retrotransposon, which is exceptionally active and has massively expanded its copy number in BmN4 cells. Many copies of torimochi in BmN4 cells have features of open chromatin and the ability to produce piRNAs. Therefore, torimochi may represent a young, growing piRNA cluster, which is still "alive" and active in transposition yet capable of trapping other transposable elements to produce de novo piRNAs.
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Affiliation(s)
- Keisuke Shoji
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (K.S); (Y.T)
| | - Yusuke Umemura
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yukihide Tomari
- Laboratory of RNA Function, Institute for Quantitative Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail: (K.S); (Y.T)
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Tan S, Huang Y, Xiong J, Gao X, Ren H, Gao S. Identification and Comparative Analysis of the miRNAs in Gonads of High-altitude Species, Batrachuperus tibetanus. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2022. [DOI: 10.1134/s1068162023010260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kawamoto M, Kiuchi T, Katsuma S. SilkBase: an integrated transcriptomic and genomic database for Bombyx mori and related species. Database (Oxford) 2022; 2022:6603636. [PMID: 35670730 PMCID: PMC9216573 DOI: 10.1093/database/baac040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/21/2022] [Accepted: 05/21/2022] [Indexed: 11/13/2022]
Abstract
We introduce SilkBase as an integrated database for transcriptomic and genomic resources of the domesticated silkworm Bombyx mori and related species. SilkBase is the oldest B. mori database that was originally established as the expressed sequence tag database since 1999. Here, we upgraded the database by including the datasets of the newly assembled B. mori complete genome sequence, predicted gene models, bacterial artificial chromosome (BAC)-end and fosmid-end sequences, complementary DNA (cDNA) reads from 69 libraries, RNA-seq data from 10 libraries, PIWI-interacting RNAs (piRNAs) from 13 libraries, ChIP-seq data of 9 histone modifications and HP1 proteins and transcriptome and/or genome data of four B. mori-related species, i.e. Bombyx mandarina, Trilocha varians, Ernolatia moorei and Samia ricini. Our new integrated genome browser easily provides a snapshot of tissue- and stage-specific gene expression, alternative splicing, production of piRNAs and histone modifications at the gene locus of interest. Moreover, SilkBase is useful for performing comparative studies among five closely related lepidopteran insects. Database URL: https://silkbase.ab.a.u-tokyo.ac.jp
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Affiliation(s)
- Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.,Infinity Matrix, Shiohama, Koto-ku, Tokyo 135-0043, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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The birth of piRNAs: how mammalian piRNAs are produced, originated, and evolved. Mamm Genome 2021; 33:293-311. [PMID: 34724117 PMCID: PMC9114089 DOI: 10.1007/s00335-021-09927-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/15/2021] [Indexed: 11/24/2022]
Abstract
PIWI-interacting RNAs (piRNAs), small noncoding RNAs 24–35 nucleotides long, are essential for animal fertility. They play critical roles in a range of functions, including transposable element suppression, gene expression regulation, imprinting, and viral defense. In mammals, piRNAs are the most abundant small RNAs in adult testes and the only small RNAs that direct epigenetic modification of chromatin in the nucleus. The production of piRNAs is a complex process from transcription to post-transcription, requiring unique machinery often distinct from the biogenesis of other RNAs. In mice, piRNA biogenesis occurs in specialized subcellular locations, involves dynamic developmental regulation, and displays sexual dimorphism. Furthermore, the genomic loci and sequences of piRNAs evolve much more rapidly than most of the genomic regions. Understanding piRNA biogenesis should reveal novel RNA regulations recognizing and processing piRNA precursors and the forces driving the gain and loss of piRNAs during animal evolution. Such findings may provide the basis for the development of engineered piRNAs capable of modulating epigenetic regulation, thereby offering possible single-dose RNA therapy without changing the genomic DNA. In this review, we focus on the biogenesis of piRNAs in mammalian adult testes that are derived from long non-coding RNAs. Although piRNA biogenesis is believed to be evolutionarily conserved from fruit flies to humans, recent studies argue for the existence of diverse, mammalian-specific RNA-processing pathways that convert precursor RNAs into piRNAs, perhaps associated with the unique features of mammalian piRNAs or germ cell development. We end with the discussion of major questions in the field, including substrate recognition and the birth of new piRNAs.
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Yang X, Chen K, Wang Y, Yang D, Huang Y. The Sex Determination Cascade in the Silkworm. Genes (Basel) 2021; 12:genes12020315. [PMID: 33672402 PMCID: PMC7926724 DOI: 10.3390/genes12020315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 12/22/2022] Open
Abstract
In insects, sex determination pathways involve three levels of master regulators: primary signals, which determine the sex; executors, which control sex-specific differentiation of tissues and organs; and transducers, which link the primary signals to the executors. The primary signals differ widely among insect species. In Diptera alone, several unrelated primary sex determiners have been identified. However, the doublesex (dsx) gene is highly conserved as the executor component across multiple insect orders. The transducer level shows an intermediate level of conservation. In many, but not all examined insects, a key transducer role is performed by transformer (tra), which controls sex-specific splicing of dsx. In Lepidoptera, studies of sex determination have focused on the lepidopteran model species Bombyx mori (the silkworm). In B. mori, the primary signal of sex determination cascade starts from Fem, a female-specific PIWI-interacting RNA, and its targeting gene Masc, which is apparently specific to and conserved among Lepidoptera. Tra has not been found in Lepidoptera. Instead, the B. mori PSI protein binds directly to dsx pre-mRNA and regulates its alternative splicing to produce male- and female-specific transcripts. Despite this basic understanding of the molecular mechanisms underlying sex determination, the links among the primary signals, transducers and executors remain largely unknown in Lepidoptera. In this review, we focus on the latest findings regarding the functions and working mechanisms of genes involved in feminization and masculinization in Lepidoptera and discuss directions for future research of sex determination in the silkworm.
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Affiliation(s)
- Xu Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kai Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaohui Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
| | - Dehong Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China; (X.Y.); (K.C.); (Y.W.); (D.Y.)
- Correspondence:
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9
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Katsuma S, Shoji K, Suzuki Y, Iwanaga M. Potential for small RNA production against Bombyx mori latent virus in Bombyx mori ovaries. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2021; 106:e21761. [PMID: 33225529 DOI: 10.1002/arch.21761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/22/2020] [Accepted: 11/03/2020] [Indexed: 06/11/2023]
Abstract
Bombyx mori latent virus (BmLV) is a positive, single-stranded insect RNA virus closely related to plant maculaviruses. BmLV was first isolated from Bombyx mori ovary-derived cell line BmN-4, and this virus has already infected most B. mori-derived cultured cell lines. We previously reported that small interfering RNA (siRNA) and PIWI-interacting RNA (piRNA) pathways function cooperatively to maintain the amount of BmLV RNA for normal BmN-4 cell growth. On the other hand, BmLV does not propagate in B. mori larvae. Here we conducted BmLV injection into the larval body cavities of B. mori, and examined BmLV accumulation in larval ovaries where siRNA and piRNA pathways are both active, to investigate whether this in vivo resistance is governed by small RNA pathways. Expression levels of RNA-dependent RNA polymerase, coat protein, and p15 genes in BmLV-injected larval ovaries were extremely low compared with those in B. mori cultured cells, indicating that B. mori larval ovaries are more resistant to BmLV than B. mori cultured cells. We also sequenced small RNAs prepared from BmLV-injected larval ovaries and mapped them onto the BmLV genome. Although their amounts were very small, we were able to detect BmLV-derived small RNAs in the ovaries. According to their length distribution and nucleotide bias, they were likely to be siRNAs and piRNAs. These results suggest that B. mori ovaries can potentially produce small RNAs against BmLV, but the resistance of larval ovaries against BmLV is not dependent on RNA silencing pathways.
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Affiliation(s)
- Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Keisuke Shoji
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Masashi Iwanaga
- Department of Agrobiology and Bioresources, Utsunomiya University, Utsunomiya-shi, Tochigi, Japan
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Wang L, Song F, Yin H, Zhu W, Fu J, Dong Z, Xu P. Comparative microRNAs expression profiles analysis during embryonic development of common carp, Cyprinus carpio. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 37:100754. [PMID: 33186873 DOI: 10.1016/j.cbd.2020.100754] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/23/2020] [Accepted: 10/26/2020] [Indexed: 12/22/2022]
Abstract
MicroRNAs (miRNAs) play important roles in biological processes by regulating specific gene expression. Limited miRNAs information is available on embryonic development in common carp (Cyprinus carpio) so far. In this study, six important embryonic development stages of C.carpio were collected to perform a times-series of small RNA-seq experiments from cleavage, blastocyst, gastrulation, organ formation, hatching stage to 1 day post-hatching larva. The expression profiles of miRNAs were identified and differentially expressed miRNAs (DEMs) were screened out based on pairwise comparison. A mean of 12,744,989 raw reads and 9,888,123 clean reads were obtained from each library. A total of 2565 miRNAs were identified. 68 of 204 DEMs were overlapped with stage-specific miRNAs, in which 15 were known miRNAs and seemed to play a key role in embryogenesis. Additionally, time-course expression reveals several intriguing fluctuations during embryogenesis. Numerous signaling pathways were identified in embryonic development, including the phototransduction, hippo signaling pathway, Wnt, melanogenesis, histidine metabolism and fatty acid biosynthesis. The results would provide new insight into the roles of miRNAs in embryonic development, and would help us to advance the understanding of miRNA-mediated mechanisms in embryonic development of fish.
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Affiliation(s)
- Lanmei Wang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu, China; Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Wuxi 214081, Jiangsu, China
| | - Feibiao Song
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu, China
| | - Haoran Yin
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu, China
| | - Wenbin Zhu
- Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Wuxi 214081, Jiangsu, China
| | - Jianjun Fu
- Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Wuxi 214081, Jiangsu, China
| | - Zaijie Dong
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu, China; Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Wuxi 214081, Jiangsu, China.
| | - Pao Xu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, Jiangsu, China; Freshwater Fisheries Research Center of Chinese Academy of Fishery Sciences, Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Wuxi 214081, Jiangsu, China.
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11
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Wang J, Yang J, Li D, Li J. Technologies for targeting DNA methylation modifications: Basic mechanism and potential application in cancer. Biochim Biophys Acta Rev Cancer 2020; 1875:188454. [PMID: 33075468 DOI: 10.1016/j.bbcan.2020.188454] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/14/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
DNA methylation abnormalities are regarded as critical event for cancer initiation and development. Tumor-associated genes encompassing aberrant DNA methylation alterations at specific locus are correlated with chromatin remodeling and dysregulation of gene expression in various malignancies. Thus, technologies designed to manipulate DNA methylation at specific loci of genome are necessary for the functional study and therapeutic application in the context of cancer management. Traditionally, the method for DNA methylation modifications demonstrates an unspecific feature, adversely causing global-genome epigenetic alterations and confusing the function of desired gene. Novel approaches for targeted DNA methylation regulation have a great advantage of manipulating gene epigenetic alterations in a more specific and efficient method. In this review, we described different targeting DNA methylation techniques, including both their advantages and limitations. Through a comprehensive understanding of these targeting tools, we hope to open a new perspective for cancer treatment.
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Affiliation(s)
- Jie Wang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China; Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing, P.R. China
| | - Jing Yang
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China; Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing, P.R. China
| | - Dandan Li
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China; Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing, P.R. China
| | - Jinming Li
- National Center for Clinical Laboratories, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R. China; Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, P.R. China; Beijing Engineering Research Center of Laboratory Medicine, Beijing Hospital, Beijing, P.R. China.
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12
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Wang F, Yang QW, Zhao WJ, Du QY, Chang ZJ. Effects of short-time exposure to atrazine on miRNA expression profiles in the gonad of common carp (Cyprinus carpio). BMC Genomics 2019; 20:587. [PMID: 31315571 PMCID: PMC6636164 DOI: 10.1186/s12864-019-5896-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 06/11/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Atrazine is widely used in agriculture and is a known endocrine disrupting chemical. Atrazine can seep into the water body through surface, posing a potential threat to the aquatic ecological environment and human drinking water source. In vertebrate, studies have shown that it can affect reproduction and development seriously, but its molecular mechanism for aquatic animals is unknown. Aquaculture is very common in China, especially common carp, whose females grow faster than males. However, the effects of atrazine on the reproduction of carp, especially miRNA, have not been investigated. RESULTS In this study, common carp (Cyprinus carpio) at two key developmental stages were exposed to atrazine in vitro. Sex ratio was observed to analyze the effect of atrazine on the sex. MiRNA expression profiles were analysed to identify miRNAs related to gonad development and to reveal the atrazine mechanisms interfering with gonad differentiation. The results showed that the sex ratio was biased towards females. Atrazine exposure caused significant alteration of multiple miRNAs. Predicted targets of differently-expressed miRNAs were involved in many reproductive biology signalling pathways. CONCLUSIONS Our results indicate that atrazine promoted the expression of female-biased genes by decreasing miRNAs in primordial gonad. In addition, our results indicate that atrazine can up-regulate aromatase expression through miRNAs, which supports the hypothesis that atrazine has endocrine-disrupting activity by altering the gene expression profile of the Hypothalamus-Pituitary-Gonad axis through its corresponding miRNAs.
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Affiliation(s)
- Fang Wang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Qian-Wen Yang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Wen-Jie Zhao
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Qi-Yan Du
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Zhong-Jie Chang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China.
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Kawamoto M, Jouraku A, Toyoda A, Yokoi K, Minakuchi Y, Katsuma S, Fujiyama A, Kiuchi T, Yamamoto K, Shimada T. High-quality genome assembly of the silkworm, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 107:53-62. [PMID: 30802494 DOI: 10.1016/j.ibmb.2019.02.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 05/21/2023]
Abstract
In 2008, the genome assembly and gene models for the domestic silkworm, Bombyx mori, were published by a Japanese and Chinese collaboration group. However, the genome assembly contains a non-negligible number of misassembled and gap regions due to the presence of many repetitive sequences within the silkworm genome. The erroneous genome assembly occasionally causes incorrect gene prediction. Here we performed hybrid assembly based on 140 × deep sequencing of long (PacBio) and short (Illumina) reads. The remaining gaps in the initial genome assembly were closed using BAC and Fosmid sequences, giving a new total length of 460.3 Mb, with 30 gap regions and an N50 comprising 16.8 Mb in scaffolds and 12.2 Mb in contigs. More RNA-seq and piRNA-seq reads were mapped on the new genome assembly compared with the previous version, indicating that the new genome assembly covers more transcribed regions, including repetitive elements. We performed gene prediction based on the new genome assembly using available mRNA and protein sequence data. The number of gene models was 16,880 with an N50 of 2154 bp. The new gene models reflected more accurate coding sequences and gene sets than old ones. The proportion of repetitive elements was also reestimated using the new genome assembly, and was calculated to be 46.8% in the silkworm genome. The new genome assembly and gene models are provided in SilkBase (http://silkbase.ab.a.u-tokyo.ac.jp).
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Affiliation(s)
- Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Akiya Jouraku
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan; Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Kakeru Yokoi
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Yohei Minakuchi
- Comparative Genomics Laboratory, Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Asao Fujiyama
- Comparative Genomics Laboratory, Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan; Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
| | - Kimiko Yamamoto
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki, 305-8634, Japan.
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
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Identification of piRNAs and piRNA clusters in the testes of the Mongolian horse. Sci Rep 2019; 9:5022. [PMID: 30903011 PMCID: PMC6430771 DOI: 10.1038/s41598-019-41475-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 03/11/2019] [Indexed: 11/10/2022] Open
Abstract
P-element induced wimpy testis-interacting RNAs (piRNAs) are essential for testicular development and spermatogenesis in mammals. Comparative analyses of the molecular mechanisms of spermatogenesis among different organisms are therefore dependent on accurate characterizations of piRNAs. At present, little is known of piRNAs in non-model organisms. Here, we characterize piRNAs in the Mongolian horse, a hardy breed that reproduces under extreme circumstances. A thorough understanding of spermatogenesis and reproduction in this breed may provide insights for the improvement of fecundity and reproductive success in other breeds. We identified 4,936,717 piRNAs and 7,890 piRNA clusters across both testicular developmental stages. Of these, 2,236,377 putative piRNAs were expressed in the mature samples only, and 2,391,271 putative piRNAs were expressed in the immature samples only. Approximately 3,016 piRNA clusters were upregulated in the mature testes as compared to the immature testes, and 4,874 piRNA clusters were downregulated. Functional and pathway analyses indicated that the candidate generating genes of the predicted piRNAs were likely involved in testicular development and spermatogenesis. Our results thus provide information about differential expression patterns in genes associated with testicular development and spermatogenesis in a non-model animal.
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15
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Wen X, Wang D, Li X, Zhao C, Wang T, Qian X, Yin S. Differential expression of two Piwil orthologs during embryonic and gonadal development in pufferfish, Takifugu fasciatus. Comp Biochem Physiol B Biochem Mol Biol 2018; 219-220:44-51. [DOI: 10.1016/j.cbpb.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/23/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
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16
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Katsuma S, Kawamoto M, Shoji K, Aizawa T, Kiuchi T, Izumi N, Ogawa M, Mashiko T, Kawasaki H, Sugano S, Tomari Y, Suzuki Y, Iwanaga M. Transcriptome profiling reveals infection strategy of an insect maculavirus. DNA Res 2018; 25:4816134. [PMID: 29360973 PMCID: PMC6014269 DOI: 10.1093/dnares/dsx056] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 01/03/2018] [Indexed: 11/14/2022] Open
Abstract
Bombyx mori macula-like virus (BmMLV) is a positive, single-stranded insect RNA virus that is closely related to plant maculaviruses. BmMLV is currently characterized as an unclassified maculavirus. BmMLV accumulates at extremely high levels in cell lines derived from the silkworm, Bombyx mori, but it does not lead to lethality and establishes persistent infections. It is unknown how this insect maculavirus replicates and establishes persistent infections in insect cells. Here, we showed that BmMLV p15, which is located on a subgenomic fragment and is not found in plant maculaviruses, is highly expressed in BmMLV-infected silkworm cells and that p15 protein is required to establish BmMLV infections in silkworm cells. We also showed that two distinct small RNA-mediated pathways maintain BmMLV levels in BmMLV-infected silkworm cells, thereby allowing the virus to establish persistent infection. Virus-derived siRNAs and piRNAs were both produced as the infection progressed. Knockdown experiments demonstrated that the exogenous RNAi pathway alone or RNAi and piRNA pathways function cooperatively to silence BmMLV RNA and that both pathways are important for normal growth of BmMLV-infected silkworm cells. On the basis of our study, we propose a mechanism of how a plant virus-like insect virus can establish persistent infections in insect cells.
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Affiliation(s)
- Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keisuke Shoji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
- Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Utsunomiya-shi, Tochigi 321-8505, Japan
| | - Takahiro Aizawa
- Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Utsunomiya-shi, Tochigi 321-8505, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Natsuko Izumi
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Moe Ogawa
- Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Utsunomiya-shi, Tochigi 321-8505, Japan
| | - Takaaki Mashiko
- Department of Biological Production Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
| | - Hideki Kawasaki
- Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Utsunomiya-shi, Tochigi 321-8505, Japan
| | - Sumio Sugano
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Yukihide Tomari
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-0882, Japan
| | - Masashi Iwanaga
- Department of Agrobiology and Bioresources, School of Agriculture, Utsunomiya University, Utsunomiya-shi, Tochigi 321-8505, Japan
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17
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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
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Macias VM, Ohm JR, Rasgon JL. Gene Drive for Mosquito Control: Where Did It Come from and Where Are We Headed? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14091006. [PMID: 28869513 PMCID: PMC5615543 DOI: 10.3390/ijerph14091006] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 02/08/2023]
Abstract
Mosquito-borne pathogens place an enormous burden on human health. The existing toolkit is insufficient to support ongoing vector-control efforts towards meeting disease elimination and eradication goals. The perspective that genetic approaches can potentially add a significant set of tools toward mosquito control is not new, but the recent improvements in site-specific gene editing with CRISPR/Cas9 systems have enhanced our ability to both study mosquito biology using reverse genetics and produce genetics-based tools. Cas9-mediated gene-editing is an efficient and adaptable platform for gene drive strategies, which have advantages over innundative release strategies for introgressing desirable suppression and pathogen-blocking genotypes into wild mosquito populations; until recently, an effective gene drive has been largely out of reach. Many considerations will inform the effective use of new genetic tools, including gene drives. Here we review the lengthy history of genetic advances in mosquito biology and discuss both the impact of efficient site-specific gene editing on vector biology and the resulting potential to deploy new genetic tools for the abatement of mosquito-borne disease.
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Affiliation(s)
- Vanessa M Macias
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
| | - Johanna R Ohm
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA.
| | - Jason L Rasgon
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA.
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA.
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA.
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19
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Abstract
Piwi proteins and their bound Piwi-interacting RNAs (piRNAs) are predominantly expressed in the germline and play crucial roles in germline development by silencing transposons and other targets. Bombyx mori BmN4 cells are culturable germ cells that equip the piRNA pathway. Because of the scarcity of piRNA-expressing culturable cells, BmN4 cells are being utilized for the analyses of piRNA biogenesis. We here report that the piRNA biogenesis in BmN4 cells is regulated by cell density. As cell density increased, the abundance of Piwi proteins and piRNA biogenesis factors was commonly upregulated, resulting in an increased number of perinuclear nuage-like granules where Piwi proteins localize. Along with these phenomena, the abundance of mature piRNAs also globally increased, whereas levels of long piRNA precursor and transposons decreased, suggesting that increasing cell density promotes piRNA biogenesis pathway and that the resultant accumulation of mature piRNAs is functionally significant for transposon silencing. Our study reveals a previously uncharacterized link between cell density and piRNA biogenesis, designates cell density as a critical variable in piRNA studies using BmN4 cell system, and suggests the alteration of cell density as a useful tool to monitor piRNA biogenesis and function.
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20
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Wang F, Jia Y, Wang P, Yang Q, Du Q, Chang Z. Identification and profiling of Cyprinus carpio microRNAs during ovary differentiation by deep sequencing. BMC Genomics 2017; 18:333. [PMID: 28454515 PMCID: PMC5410099 DOI: 10.1186/s12864-017-3701-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 04/11/2017] [Indexed: 12/19/2022] Open
Abstract
Background MicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression by targeting specific mRNAs. However, the possible role of miRNAs in the ovary differentiation and development of fish is not well understood. In this study, we examined the expression profiles and differential expression of miRNAs during three key stages of ovarian development and different developmental stages in common carp Cyprinus carpio. Results A total of 8765 miRNAs were identified, including 2155 conserved miRNAs highly conserved among various species, 145 miRNAs registered in miRBase for common carp, and 6505 novel miRNAs identified in common carp for the first time. Comparison of miRNA expression profiles among the five libraries identified 714 co-expressed and 2382 specific expressed miRNAs. Overall, 150, 628, and 431 specifically expressed miRNAs were identified in primordial gonad, juvenile ovary, and adult ovary, respectively. MiR-6758-3p, miR-3050-5p, and miR-2985-3p were highly expressed in primordial gonad, miR-3544-5p, miR-6877-3p, and miR-9086-5p were highly expressed in juvenile ovary, and miR-154-3p, miR-5307-5p, and miR-3958-3p were highly expressed in adult ovary. Predicted target genes of specific miRNAs in primordial gonad were involved in many reproductive biology signaling pathways, including transforming growth factor-β, Wnt, oocyte meiosis, mitogen-activated protein kinase, Notch, p53, and gonadotropin-releasing hormone pathways. Target-gene prediction revealed upward trends in miRNAs targeting male-bias genes, including dmrt1, atm, gsdf, and sox9, and downward trends in miRNAs targeting female-bias genes including foxl2, smad3, and smad4. Other sex-related genes such as sf1 were also predicted to be miRNA target genes. Conclusions This comprehensive miRNA transcriptome analysis demonstrated differential expression profiles of miRNAs during ovary development in common carp. These results could facilitate future exploitation of the sex-regulatory roles and mechanisms of miRNAs, especially in primordial gonads, while the specifically expressed miRNAs represent candidates for studying the mechanisms of ovary determination in Yellow River carp. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3701-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fang Wang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China.
| | - Yongfang Jia
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Po Wang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - Qianwen Yang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - QiYan Du
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
| | - ZhongJie Chang
- College of Life Science, Henan Normal University, Xinxiang, Henan, 453007, People's Republic of China
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21
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Shoji K, Suzuki Y, Sugano S, Shimada T, Katsuma S. Artificial "ping-pong" cascade of PIWI-interacting RNA in silkworm cells. RNA (NEW YORK, N.Y.) 2017; 23:86-97. [PMID: 27777367 PMCID: PMC5159652 DOI: 10.1261/rna.058875.116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 10/15/2016] [Indexed: 05/19/2023]
Abstract
PIWI-interacting RNAs (piRNAs) play essential roles in the defense system against selfish elements in animal germline cells by cooperating with PIWI proteins. A subset of piRNAs is predicted to be generated via the "ping-pong" cascade, which is mainly controlled by two different PIWI proteins. Here we established a cell-based artificial piRNA production system using a silkworm ovarian cultured cell line that is believed to possess a complete piRNA pathway. In addition, we took advantage of a unique silkworm sex-determining one-to-one ping-pong piRNA pair, which enabled us to precisely monitor the behavior of individual artificial piRNAs. With this novel strategy, we successfully generated artificial piRNAs against endogenous protein-coding genes via the expected back-and-forth traveling mechanism. Furthermore, we detected "primary" piRNAs from the upstream region of the artificial "ping-pong" site in the endogenous gene. This artificial piRNA production system experimentally confirms the existence of the "ping-pong" cascade of piRNAs. Also, this system will enable us to identify the factors involved in both, or each, of the "ping" and "pong" cascades and the sequence features that are required for efficient piRNA production.
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Affiliation(s)
- Keisuke Shoji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yutaka Suzuki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-0882, Japan
| | - Sumio Sugano
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
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22
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Liu P, Dong Y, Gu J, Puthiyakunnon S, Wu Y, Chen XG. Developmental piRNA profiles of the invasive vector mosquito Aedes albopictus. Parasit Vectors 2016; 9:524. [PMID: 27686069 PMCID: PMC5041409 DOI: 10.1186/s13071-016-1815-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 09/22/2016] [Indexed: 12/13/2022] Open
Abstract
Background In eukaryotic organisms, Piwi-interacting RNAs (piRNAs) control the activities of mobile genetic elements and ensure genome maintenance. Recent evidence indicates that piRNAs are involved in multiple biological pathways, including transcriptional regulation of protein-coding genes, sex determination and even interactions between host and pathogens. Aedes albopictus is a major invasive species that transmits a number of viral diseases in humans. Ae. albopictus has the largest genome and the highest abundance of repetitive sequences when compared with members that belong to Culicidae with a published genome. Analysis of piRNA profiles will provide a developmental and evolutionary perspective on piRNAs in Ae. albopictus. Methods piRNAs were identified and characterized during the development of Ae. albopictus, and piRNA expression patterns in adult males and females as well as sugar-fed females and blood-fed females were compared. Results Our results reveal that, despite the large genome size of Ae. albopictus, the piRNA pool of Ae. albopictus (1.2 × 107) is smaller than those of Aedes aegypti (1.7 × 107) and Drosophila melanogaster (1.6 × 107). In Ae. albopictus, piRNAs displayed the highest abundance at the embryo stage and the lowest abundance at the pupal stage. Approximately 50 % of the piRNAs mapped to intergenic regions with no known functions. Approximately 30 % of the piRNAs mapped to repetitive elements, and 77.69 % of these repeat-derived piRNAs mapped to Class I TEs; 45.42 % of the observed piRNA reads originated from piRNA clusters, and most of the top 10 highest expressed piRNA clusters and 100 highest expressed piRNAs from each stage displayed biased expression patterns across the developmental stages. All anti-sense-derived piRNAs displayed a preference for uridine at the 5′ end; however, the sense-derived piRNAs showed adenine bias at the tenth nucleotide position and a typical ping-pong signature, suggesting that the biogenesis of piRNAs was conserved throughout development. Our results also show that 962 piRNAs displayed sex-biased expression, and 522 piRNAs showed higher expression in the blood-fed females than in the sugar-fed females. Conclusions Our results suggest that piRNAs, aside from silencing transposable elements in Ae. albopictus, may have a role in other biological pathways. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1815-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Peiwen Liu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Yunqiao Dong
- Reproductive Medical Centre of Guangdong Women and Children Hospital, Guangzhou, Guangdong, 511442, China
| | - Jinbao Gu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China.
| | - Santhosh Puthiyakunnon
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Yang Wu
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China
| | - Xiao-Guang Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, 510515, China.
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23
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Rosenkranz D. piRNA cluster database: a web resource for piRNA producing loci. Nucleic Acids Res 2015; 44:D223-30. [PMID: 26582915 PMCID: PMC4702893 DOI: 10.1093/nar/gkv1265] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/03/2015] [Indexed: 12/14/2022] Open
Abstract
Piwi proteins and their guiding small RNAs, termed Piwi-interacting (pi-) RNAs, are essential for silencing of transposons in the germline of animals. A substantial fraction of piRNAs originates from genomic loci termed piRNA clusters and sequences encoded in these piRNA clusters determine putative targets for the Piwi/piRNA system. In the past decade, studies of piRNA transcriptomes in different species revealed additional roles for piRNAs beyond transposon silencing, reflecting the astonishing plasticity of the Piwi/piRNA system along different phylogenetic branches. Moreover, piRNA transcriptomes can change drastically during development and vary across different tissues. Since piRNA clusters crucially shape piRNA profiles, analysis of these loci is imperative for a thorough understanding of functional and evolutionary aspects of the piRNA pathway. But despite the ever-growing amount of available piRNA sequence data, we know little about the factors that determine differential regulation of piRNA clusters, nor the evolutionary events that cause their gain or loss. In order to facilitate addressing these subjects, we established a user-friendly piRNA cluster database (http://www.smallrnagroup-mainz.de/piRNAclusterDB.html) that provides comprehensive data on piRNA clusters in multiple species, tissues and developmental stages based on small RNA sequence data deposited at NCBI's Sequence Read Archive (SRA).
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Affiliation(s)
- David Rosenkranz
- Institute of Anthropology, Johannes Gutenberg University, Mainz 55099, Germany
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24
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Abstract
The W chromosome of the silkworm Bombyx mori has been known to determine femaleness for more than 80 years. However, the feminizing gene has not been molecularly identified, because the B. mori W chromosome is almost fully occupied by a large number of transposable elements. The W chromosome-derived feminizing factor of B. mori was recently shown to be a female-specific PIWI-interacting RNA (piRNA). piRNAs are small RNAs that potentially repress invading “non-self” elements (e.g., transposons and virus-like elements) by associating with PIWI proteins. Our results revealed that female-specific piRNA precursors, which we named Fem, are transcribed from the sex-determining region of the W chromosome at the early embryonic stage and are processed into a single mature piRNA (Fem piRNA). Fem piRNA forms a complex with Siwi (silkworm Piwi), which cleaves a protein-coding mRNA transcribed from the Z chromosome. RNA interference of this Z-linked gene, which we named Masc, revealed that this gene encodes a protein required for masculinization and dosage compensation. Fem and Masc both participate in the ping-pong cycle of the piRNA amplification loop by associating with the 2 B. mori PIWI proteins Siwi and BmAgo3 (silkworm Ago3), respectively, indicating that the piRNA-mediated interaction between the 2 sex chromosomes is the primary signal for the B. mori sex determination cascade. Fem is a non-transposable repetitive sequence on the W chromosome, whereas Masc is a single-copy protein-coding gene. It is of great interest how the piRNA system recognizes “self ”Masc mRNA as “non-self” RNA.
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Affiliation(s)
- Susumu Katsuma
- a Department of Agricultural and Environmental Biology; Graduate School of Agricultural and Life Sciences ; The University of Tokyo ; Bunkyo-ku , Tokyo , Japan
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25
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Shoji K, Katsuma S. Is the expression of sense and antisense transgenes really sufficient for artificial piRNA production? Curr Biol 2015; 25:R708-10. [DOI: 10.1016/j.cub.2015.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Itou D, Shiromoto Y, Yukiho SY, Ishii C, Nishimura T, Ogonuki N, Ogura A, Hasuwa H, Fujihara Y, Kuramochi-Miyagawa S, Nakano T. Induction of DNA methylation by artificial piRNA production in male germ cells. Curr Biol 2015; 25:901-6. [PMID: 25772451 DOI: 10.1016/j.cub.2015.01.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 12/28/2014] [Accepted: 01/23/2015] [Indexed: 12/13/2022]
Abstract
Global DNA demethylation and subsequent de novo DNA methylation take place in mammalian male embryonic germ cells [1-3]. P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs), which are germline-specific small RNAs, have been postulated to be critically important for de novo DNA methylation of retrotransposon genes, and many proteins, including PIWI family proteins, play pivotal roles in this process [4-6]. In the embryonic mouse testis, two mouse PIWI proteins, mouse PIWI-like (MILI) and mouse PIWI2 (MIWI2), are involved in the biogenesis of piRNAs through the so-called ping-pong amplification cycle [7-10], and long single-stranded RNAs transcribed from the gene regions of piRNA clusters have been proposed to be the initial material [11-16]. However, it remains unclear whether transcription from the piRNA clusters is required for the biogenesis of piRNAs. To answer this question, we developed a novel artificial piRNA production system by simple expression of sense and antisense EGFP mRNAs in embryonic male germ cells in the piRNA biogenesis phase. EGFP expression was silenced by piRNA-dependent DNA methylation, indicating that concomitant expression of sense and antisense RNA transcripts is necessary and sufficient for piRNA production and subsequent piRNA-dependent gene silencing. In addition, we demonstrated that this artificial piRNA induction paradigm could be applied to an endogenous gene essential for spermatogenesis, DNMT3L [3, 17, 18]. This study not only provides novel insights into the molecular mechanisms of piRNA production, but also presents an innovative strategy for inducing epigenetic modification in germ cells.
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Affiliation(s)
- Daisuke Itou
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Yusuke Shiromoto
- Medical School, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Shin-ya Yukiho
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Chika Ishii
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Toru Nishimura
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Narumi Ogonuki
- RIKEN BioResources Center, Tsukuba 305-0074, Ibaraki, Japan
| | - Atsuo Ogura
- RIKEN BioResources Center, Tsukuba 305-0074, Ibaraki, Japan
| | - Hidetoshi Hasuwa
- Research Institute for Microbial Diseases, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan
| | - Yoshitaka Fujihara
- Research Institute for Microbial Diseases, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan
| | - Satomi Kuramochi-Miyagawa
- Medical School, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.
| | - Toru Nakano
- Department of Pathology, Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; Medical School, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan; CREST, Japan Science and Technology Agency (JST), Saitama 332-0012, Japan.
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Song J, Liu J, Schnakenberg SL, Ha H, Xing J, Chen KC. Variation in piRNA and transposable element content in strains of Drosophila melanogaster. Genome Biol Evol 2014; 6:2786-98. [PMID: 25267446 PMCID: PMC4224344 DOI: 10.1093/gbe/evu217] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Transposable elements (TEs) are one of the most important features of genome architecture, so their evolution and relationship with host defense mechanisms have been topics of intense study, especially in model systems such as Drosophila melanogaster. Recently, a novel small RNA-based defense mechanism in animals called the Piwi-interacting RNA (piRNA) pathway was discovered to form an adaptive defense mechanism against TEs. To investigate the relationship between piRNA and TE content between strains of a species, we sequenced piRNAs from 16 inbred lines of D. melanogaster from the Drosophila Genetic Reference Panel. Instead of a global correlation of piRNA expression and TE content, we found evidence for a host response through de novo piRNA production from novel TE insertions. Although approximately 20% of novel TE insertions induced de novo piRNA production, the abundance of de novo piRNAs was low and did not markedly affect the global pool of ovarian piRNAs. Our results provide new insights into the evolution of TEs and the piRNA system in an important model organism.
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Affiliation(s)
- Jimin Song
- Department of Genetics, Rutgers University BioMaPS Institute for Quantitative Biology, Rutgers University
| | - Jixia Liu
- Department of Genetics, Rutgers University BioMaPS Institute for Quantitative Biology, Rutgers University Human Genetics Institute of New Jersey, Rutgers University
| | - Sandra L Schnakenberg
- Department of Genetics, Rutgers University BioMaPS Institute for Quantitative Biology, Rutgers University Developmental Biology Program, Sloan-Kettering Institute, New York, NY
| | - Hongseok Ha
- Department of Genetics, Rutgers University Human Genetics Institute of New Jersey, Rutgers University
| | - Jinchuan Xing
- Department of Genetics, Rutgers University Human Genetics Institute of New Jersey, Rutgers University
| | - Kevin C Chen
- Department of Genetics, Rutgers University BioMaPS Institute for Quantitative Biology, Rutgers University
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Shoji K, Hara K, Kawamoto M, Kiuchi T, Kawaoka S, Sugano S, Shimada T, Suzuki Y, Katsuma S. Silkworm HP1a transcriptionally enhances highly expressed euchromatic genes via association with their transcription start sites. Nucleic Acids Res 2014; 42:11462-71. [PMID: 25237056 PMCID: PMC4191426 DOI: 10.1093/nar/gku862] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Heterochromatin protein 1 (HP1) is an evolutionarily conserved protein across different eukaryotic species and is crucial for heterochromatin establishment and maintenance. The silkworm, Bombyx mori, encodes two HP1 proteins, BmHP1a and BmHP1b. In order to investigate the role of BmHP1a in transcriptional regulation, we performed genome-wide analyses of the transcriptome, transcription start sites (TSSs), chromatin modification states and BmHP1a-binding sites of the silkworm ovary-derived BmN4 cell line. We identified a number of BmHP1a-binding loci throughout the silkworm genome and found that these loci included TSSs and frequently co-occurred with neighboring euchromatic histone modifications. In addition, we observed that genes with BmHP1a-associated TSSs were relatively highly expressed in BmN4 cells. RNA interference-mediated BmHP1a depletion resulted in the transcriptional repression of highly expressed genes with BmHP1a-associated TSSs, whereas genes not coupled with BmHP1a-binding regions were less affected by the treatment. These results demonstrate that BmHP1a binds near TSSs of highly expressed euchromatic genes and positively regulates their expression. Our study revealed a novel mode of transcriptional regulation mediated by HP1 proteins.
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Affiliation(s)
- Keisuke Shoji
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kahori Hara
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Munetaka Kawamoto
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Kiuchi
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shinpei Kawaoka
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yutaka Suzuki
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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Olovnikov IA, Kalmykova AI. piRNA clusters as a main source of small RNAs in the animal germline. BIOCHEMISTRY (MOSCOW) 2014; 78:572-84. [PMID: 23980884 DOI: 10.1134/s0006297913060035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
PIWI subfamily Argonaute proteins and small RNAs bound to them (PIWI interacting RNA, piRNA) control mobilization of transposable elements (TE) in the animal germline. piRNAs are generated by distinct genomic regions termed piRNA clusters. piRNA clusters are often extensive loci enriched in damaged fragments of TEs. New TE integration into piRNA clusters causes production of TE-specific piRNAs and repression of cognate sequences. piRNAs are thought to be generated from long single-stranded precursors encoded by piRNA clusters. Special chromatin structures might be essential to distinguish these genomic loci as a source for piRNAs. In this review, we present recent findings on the structural organization of piRNA clusters and piRNA biogenesis in Drosophila and other organisms, which are important for understanding a key epigenetic mechanism that provides defense against TE expansion.
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Affiliation(s)
- I A Olovnikov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia.
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Bortvin A. PIWI-interacting RNAs (piRNAs) - a mouse testis perspective. BIOCHEMISTRY (MOSCOW) 2014; 78:592-602. [PMID: 23980886 DOI: 10.1134/s0006297913060059] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Over the past decade, PIWI-interacting RNAs (piRNAs) have emerged as the most intriguing class of small RNAs. Almost every aspect of piRNA biology defies established rules of the RNA interference world while the scope of piRNA functional potential spans from transcriptional gene silencing to genome defense to transgenerational epigenetic phenomena. This review will focus on the genomic origins, biogenesis, and function of piRNAs in the mouse testis - an exceptionally robust experimental system amenable to genetic, cell-biological, molecular, and biochemical studies. Aided and frequently guided by knowledge obtained in insect, worm, and fish germ cells, mouse spermatogenesis has emerged as the primary model in understanding the role of this conserved pathway in mammals.
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Affiliation(s)
- A Bortvin
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21218, USA.
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Zhou Y, Zhong H, Liu S, Yu F, Hu J, Zhang C, Tao M, Liu Y. Elevated expression of Piwi and piRNAs in ovaries of triploid crucian carp. Mol Cell Endocrinol 2014; 383:1-9. [PMID: 24316377 DOI: 10.1016/j.mce.2013.11.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 10/19/2013] [Accepted: 11/28/2013] [Indexed: 11/29/2022]
Abstract
Increasing piRNAs provide RNA-interference pathways to regulate transposons and gene expression in germline cells. We demonstrate that Piwi transcripts are exclusively expressed in adult testes and ovaries in teleosts, with triploids showing the highest Piwi expression in the ovaries. Studies in vivo and in vitro showed that hCG and E2 treatment suppressed Piwi expression. We further cloned 200 small RNAs in the three kinds of fish. Seven piRNAs were obtained from all the three different ploidy fishes. During ovulation, five piRNAs showed significantly higher expression in the ovaries of sterile triploids than fertile diploids and tetraploids. Furthermore, E2 suppressed the expression of the six piRNAs at different levels in vivo and in vitro. The present study bridges the gap between the HPG axis and Piwi-piRNA pathway by suggesting that a dysfunctional HPG axis abrogated the piRNA suppression in triploid fish.
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Affiliation(s)
- Yi Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Huan Zhong
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Shaojun Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
| | - Fan Yu
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Jie Hu
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Chun Zhang
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Min Tao
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Yun Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of State Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, China
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Clark JP, Lau NC. Piwi Proteins and piRNAs step onto the systems biology stage. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:159-97. [PMID: 25201106 PMCID: PMC4248790 DOI: 10.1007/978-1-4939-1221-6_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Animal germ cells are totipotent because they maintain a highly unique and specialized epigenetic state for its genome. To accomplish this, germ cells express a rich repertoire of specialized RNA-binding protein complexes such as the Piwi proteins and Piwi-interacting RNAs (piRNAs): a germ-cell branch of the RNA interference (RNAi) phenomenon which includes microRNA and endogenous small interfering RNA pathways. Piwi proteins and piRNAs are deeply conserved in animal evolution and play essential roles in fertility and regeneration. Molecular mechanisms for how these ribonucleoproteins act upon the transcriptome and genome are only now coming to light with the application of systems-wide approaches in both invertebrates and vertebrates. Systems biology studies on invertebrates have revealed that transcriptional and heritable silencing is a main mechanism driven by Piwi proteins and piRNA complexes. In vertebrates, Piwi-targeting mechanisms and piRNA biogenesis have progressed, while the discovery that the nuclease activity of Piwi protein is essential for vertebrate germ cell development but not completely required in invertebrates highlights the many complexities of this pathway in different animals. This review recounts how recent systems-wide approaches have rapidly accelerated our appreciation for the broad reach of the Piwi pathway on germline genome regulation and what questions facing the field await to be unraveled.
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Affiliation(s)
- Josef P. Clark
- Department of Biology and Rosenstiel Biomedical Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
| | - Nelson C. Lau
- Department of Biology and Rosenstiel Biomedical Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA
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Nie Z, Zhou F, Li D, Lv Z, Chen J, Liu Y, Shu J, Sheng Q, Yu W, Zhang W, Jiang C, Yao Y, Yao J, Jin Y, Zhang Y. RIP-seq of BmAgo2-associated small RNAs reveal various types of small non-coding RNAs in the silkworm, Bombyx mori. BMC Genomics 2013; 14:661. [PMID: 24074203 PMCID: PMC3849828 DOI: 10.1186/1471-2164-14-661] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 09/26/2013] [Indexed: 12/21/2022] Open
Abstract
Background Small non-coding RNAs (ncRNAs) are important regulators of gene expression in eukaryotes. Previously, only microRNAs (miRNAs) and piRNAs have been identified in the silkworm, Bombyx mori. Furthermore, only ncRNAs (50-500nt) of intermediate size have been systematically identified in the silkworm. Results Here, we performed a systematic identification and analysis of small RNAs (18-50nt) associated with the Bombyx mori argonaute2 (BmAgo2) protein. Using RIP-seq, we identified various types of small ncRNAs associated with BmAGO2. These ncRNAs showed a multimodal length distribution, with three peaks at ~20nt, ~27nt and ~33nt, which included tRNA-, transposable element (TE)-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. The tRNA-derived fragments (tRFs) were found at an extremely high abundance and accounted for 69.90% of the BmAgo2-associated small RNAs. Northern blotting confirmed that many tRFs were expressed or up-regulated only in the BmNPV-infected cells, implying that the tRFs play a prominent role by binding to BmAgo2 during BmNPV infection. Additional evidence suggested that there are potential cleavage sites on the D, anti-codon and TψC loops of the tRNAs. TE-derived small RNAs and piRNAs also accounted for a significant proportion of the BmAgo2-associated small RNAs, suggesting that BmAgo2 could be involved in the maintenance of genome stability by suppressing the activities of transposons guided by these small RNAs. Finally, Northern blotting was also used to confirm the Bombyx 5.8 s rRNA-derived small RNAs, demonstrating that various novel small RNAs exist in the silkworm. Conclusions Using an RIP-seq method in combination with Northern blotting, we identified various types of small RNAs associated with the BmAgo2 protein, including tRNA-, TE-, rRNA-, snoRNA- and snRNA-derived small RNAs as well as miRNAs and piRNAs. Our findings provide new clues for future functional studies of the role of small RNAs in insect development and evolution.
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Affiliation(s)
- Zuoming Nie
- College of Life Sciences, Zhejiang Sci-Tech University, Hanghzou 310018, China.
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Izumi N, Kawaoka S, Yasuhara S, Suzuki Y, Sugano S, Katsuma S, Tomari Y. Hsp90 facilitates accurate loading of precursor piRNAs into PIWI proteins. RNA (NEW YORK, N.Y.) 2013; 19:896-901. [PMID: 23681506 PMCID: PMC3683924 DOI: 10.1261/rna.037200.112] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
PIWI-interacting RNAs (piRNAs) defend the genome against transposon activity in animal gonads. The Hsp90 chaperone machinery has been implicated in the piRNA pathway, but its exact role remains obscure. Here, we examined the effect of 17-N-allylamino-17-demethoxygeldanamycin (17-AAG), an Hsp90-specific inhibitor, on the piRNA pathway. In the silkworm ovary-derived BmN4 cells, 17-AAG treatment reduced the level of piRNAs and PIWI proteins. In vitro, the 5'-nucleotide preference upon precursor piRNA loading was compromised by 17-AAG, whereas 3'-end trimming and 2'-O-methylation were unaffected. Our data highlight a role of Hsp90 in accurate loading of precursor piRNAs into PIWI proteins.
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Affiliation(s)
- Natsuko Izumi
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Shinpei Kawaoka
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Satoshi Yasuhara
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yutaka Suzuki
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
- Corresponding authorsE-mail E-mail
| | - Yukihide Tomari
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
- Corresponding authorsE-mail E-mail
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Kaaij LJ, Hoogstrate SW, Berezikov E, Ketting RF. piRNA dynamics in divergent zebrafish strains reveal long-lasting maternal influence on zygotic piRNA profiles. RNA (NEW YORK, N.Y.) 2013; 19:345-356. [PMID: 23335638 PMCID: PMC3677245 DOI: 10.1261/rna.036400.112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 12/20/2012] [Indexed: 06/01/2023]
Abstract
Transposable elements (TEs) are mobile genetic elements that can have many deleterious effects on the fitness of their host. The germline-specific PIWI pathway guards the genome against TEs, deriving its specificity from sequence complementarity between PIWI-bound small RNAs (piRNAs) and the TEs. The piRNAs are derived from so-called piRNA clusters. Recent studies have demonstrated that the piRNA repertoire can be adjusted to accommodate recent TE invasions by capturing invading TEs in piRNA loci. Thus far, no information concerning piRNA divergence is available from vertebrates. We present piRNA analyses of two relatively divergent zebrafish strains. We find that significant differences in the piRNA populations have accumulated, most notably among active class I TEs. This divergence can be split into differences in piRNA abundance per element and differences in sense/antisense polarity ratios. In crosses between animals of the different strains, many of these differences are resolved in the progeny. However, some differences remain, often leaning to the maternally contributed piRNA population. These differences can be detected at least two generations later. Our data illustrate, for the first time, the fluidity of piRNA populations in vertebrates and how the established diversity is transmitted to future generations.
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Kawaoka S, Hara K, Shoji K, Kobayashi M, Shimada T, Sugano S, Tomari Y, Suzuki Y, Katsuma S. The comprehensive epigenome map of piRNA clusters. Nucleic Acids Res 2012; 41:1581-90. [PMID: 23258708 PMCID: PMC3561999 DOI: 10.1093/nar/gks1275] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PIWI-interacting RNA (piRNA) clusters act as anti-transposon/retrovirus centers. Integration of selfish jumping elements into piRNA clusters generates de novo piRNAs, which in turn exert trans-silencing activity against these elements in animal gonads. To date, neither genome-wide chromatin modification states of piRNA clusters nor a mode for piRNA precursor transcription have been well understood. Here, to understand the chromatin landscape of piRNA clusters and how piRNA precursors are generated, we analyzed the transcriptome, transcription start sites (TSSs) and the chromatin landscape of the BmN4 cell line, which harbors the germ-line piRNA pathway. Notably, our epigenomic map demonstrated the highly euchromatic nature of unique piRNA clusters. RNA polymerase II was enriched for TSSs that transcribe piRNA precursors. piRNA precursors possessed 5'-cap structures as well as 3'-poly A-tails. Collectively, we envision that the euchromatic, opened nature of unique piRNA clusters or piRNA cluster-associated TSSs allows piRNA clusters to capture new insertions efficiently.
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Affiliation(s)
- Shinpei Kawaoka
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Tokyo, Japan.
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Spadaro PA, Bredy TW. Emerging role of non-coding RNA in neural plasticity, cognitive function, and neuropsychiatric disorders. Front Genet 2012; 3:132. [PMID: 22811697 PMCID: PMC3395882 DOI: 10.3389/fgene.2012.00132] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/28/2012] [Indexed: 11/18/2022] Open
Abstract
Non-coding RNAs (ncRNAs) have emerged as critical regulators of transcription, epigenetic processes, and gene silencing, which make them ideal candidates for insight into molecular evolution and a better understanding of the molecular pathways of neuropsychiatric disease. Here, we provide an overview of the current state of knowledge regarding various classes of ncRNAs and their role in neural plasticity and cognitive function, and highlight the potential contribution they may make to the development of a variety of neuropsychiatric disorders, including schizophrenia, addiction, and fear-related anxiety disorders.
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Affiliation(s)
- Paola A Spadaro
- Psychiatric Epigenomics Laboratory, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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