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Kondratov KA, Artamonov AA, Nikitin YV, Velmiskina AA, Mikhailovskii VY, Mosenko SV, Polkovnikova IA, Asinovskaya AY, Apalko SV, Sushentseva NN, Ivanov AM, Scherbak SG. Revealing differential expression patterns of piRNA in FACS blood cells of SARS-CoV-2 infected patients. BMC Med Genomics 2024; 17:212. [PMID: 39143590 PMCID: PMC11325581 DOI: 10.1186/s12920-024-01982-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 08/05/2024] [Indexed: 08/16/2024] Open
Abstract
Non-coding RNA expression has shown to have cell type-specificity. The regulatory characteristics of these molecules are impacted by changes in their expression levels. We performed next-generation sequencing and examined small RNA-seq data obtained from 6 different types of blood cells separated by fluorescence-activated cell sorting of severe COVID-19 patients and healthy control donors. In addition to examining the behavior of piRNA in the blood cells of severe SARS-CoV-2 infected patients, our aim was to present a distinct piRNA differential expression portrait for each separate cell type. We observed that depending on the type of cell, different sorted control cells (erythrocytes, monocytes, lymphocytes, eosinophils, basophils, and neutrophils) have altering piRNA expression patterns. After analyzing the expression of piRNAs in each set of sorted cells from patients with severe COVID-19, we observed 3 significantly elevated piRNAs - piR-33,123, piR-34,765, piR-43,768 and 9 downregulated piRNAs in erythrocytes. In lymphocytes, all 19 piRNAs were upregulated. Monocytes were presented with a larger amount of statistically significant piRNA, 5 upregulated (piR-49039 piR-31623, piR-37213, piR-44721, piR-44720) and 35 downregulated. It has been previously shown that piR-31,623 has been associated with respiratory syncytial virus infection, and taking in account the major role of piRNA in transposon silencing, we presume that the differential expression patterns which we observed could be a signal of indirect antiviral activity or a specific antiviral cell state. Additionally, in lymphocytes, all 19 piRNAs were upregulated.
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Affiliation(s)
- Kirill A Kondratov
- City Hospital, No. 40 St, Petersburg, 197706, Russia.
- S. M. Kirov Military Medical Academy, St. Petersburg, 194044, Russia.
- Saint-Petersburg State University, St. Petersburg, 199034, Russia.
| | | | - Yuri V Nikitin
- S. M. Kirov Military Medical Academy, St. Petersburg, 194044, Russia
| | - Anastasiya A Velmiskina
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
| | | | - Sergey V Mosenko
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
| | - Irina A Polkovnikova
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
| | - Anna Yu Asinovskaya
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
| | - Svetlana V Apalko
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
| | | | - Andrey M Ivanov
- S. M. Kirov Military Medical Academy, St. Petersburg, 194044, Russia
| | - Sergey G Scherbak
- City Hospital, No. 40 St, Petersburg, 197706, Russia
- Saint-Petersburg State University, St. Petersburg, 199034, Russia
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Seistrup AS, Choppin M, Govind S, Feldmeyer B, Kever M, Karaulanov E, Séguret A, Karunanithi S, Almeida MV, Ketting RF, Foitzik S. Age- and caste-independent piRNAs in the germline and miRNA profiles linked to caste and fecundity in the ant Temnothorax rugatulus. Mol Ecol 2023; 32:6027-6043. [PMID: 37830492 DOI: 10.1111/mec.17162] [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: 05/22/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
Social insects are models for studies of phenotypic plasticity. Ant queens and workers vary in fecundity and lifespan, which are enhanced and extended in queens. Yet, the regulatory mechanisms underlying this variation are not well understood. Ant queens live and reproduce for years, so that they need to protect their germline from transposable element (TE) activity, which may be redundant in short-lived, often sterile workers. We analysed the expression of two protective classes of small RNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), in various tissues, castes and age classes of the ant Temnothorax rugatulus. In queens, piRNAs were highly abundant in ovaries with TEs being their clear targets, with reduced but still detectable piRNA-specific ping-pong signatures in thorax and brains. piRNA pathway activity varied little with age in queens. Moreover, the reduced ovaries of workers also exhibited similar piRNA activity and this not only in young, fertile workers, but also in older foragers with regressed ovaries. Therefore, these ants protect their germline through piRNA activity, regardless of ovarian development, age or caste, even in sterile workers often considered the soma of the superorganism. Our tissue-specific miRNA analysis detected the expression of 304 miRNAs, of which 105 were expressed in all tissues, 10 enriched in the brain, three in the thorax, whereas 83 were ovarian-specific. We identified ovarian miRNAs whose expression was related to caste, fecundity and age, and which likely regulate group-specific gene expression. sRNA shifts in young- to middle-aged queens were minor, suggesting delayed senescence in this reproductive caste.
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Affiliation(s)
- Ann-Sophie Seistrup
- Institute of Molecular Biology, Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Marina Choppin
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Shamitha Govind
- Institute of Molecular Biology, Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Barbara Feldmeyer
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Molecular Ecology, Frankfurt, Germany
| | - Marion Kever
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
| | | | - Alice Séguret
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Miguel V Almeida
- Institute of Molecular Biology, Mainz, Germany
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - René F Ketting
- Institute of Molecular Biology, Mainz, Germany
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Susanne Foitzik
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University Mainz, Mainz, Germany
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Lakhotia SC. C-value paradox: Genesis in misconception that natural selection follows anthropocentric parameters of 'economy' and 'optimum'. BBA ADVANCES 2023; 4:100107. [PMID: 37868661 PMCID: PMC10587719 DOI: 10.1016/j.bbadva.2023.100107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/24/2023] Open
Abstract
C-value paradox refers to the lack of correlation between biological complexity and the intuitively expected protein-coding genomic information or DNA content. Here I discuss five questions about this paradox: i) Do biologically complex organisms carry more protein-coding genes? ii) Does variable accumulation of selfish/ junk/ parasitic DNA underlie the c-value paradox? iii) Can nucleoskeletal or nucleotypic function of DNA explain the enigma of orders of magnitude high levels of DNA in some 'lower' taxa or in taxonomically related species? iv) Can the newly understood noncoding but functional DNA explain the c-value paradox? and, v) Does natural selection uniformly apply the anthropocentric parameters for 'optimum' and 'economy'? Answers to Q.1-5 are largely negative. Biology presents numerous 'anomalous' examples where the same end function/ phenotype is attained in different organisms through astoundingly diverse ways that appear 'illogical' in our perceptions. Such evolutionary oddities exist because natural selection, unlike a designer, exploits random and stochastic events to modulate the existing system. Consequently, persistence of the new-found 'solution/s' often appear bizarre, uneconomic, and therefore, paradoxical to human logic. The unexpectedly high c-values in diverse organisms are irreversible evolutionary accidents that persisted, and the additional DNA often got repurposed over the evolutionary time scale. Therefore, the c-value paradox is a redundant issue. Future integrative biological studies should address evolutionary mechanisms and processes underlying sporadic DNA expansions/ contractions, and how the newly acquired DNA content has been repurposed in diverse groups.
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Affiliation(s)
- Subhash C. Lakhotia
- Cytogenetics Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India
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Sohn EJ, Oh SO. P-Element-Induced Wimpy Testis Proteins and P-Element-Induced Wimpy Testis-Interacting RNAs Expression in Ovarian Cancer Stem Cells. Genet Test Mol Biomarkers 2023; 27:56-64. [PMID: 36853842 DOI: 10.1089/gtmb.2022.0113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Background: P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a type of noncoding RNA and are predominantly expressed in germline cells. piRNAs function as gene regulators and potential biomarkers for the development of a number of malignancies. The biological importance of piRNAs in ovarian cancer is still unknown. In this study, we investigated the expression of piRNAs in ovarian cancer stem cells and compared it with that in adherent cells. Methods: To assess changes in the expression levels of PIWIL1/HIWI, PIWIL2/HILI, PIWIL3, and PIWIL4/HIWI2, we used quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis. Changes in piRNA expression levels in ovarian cancer stem cells were analyzed using Arraystar piRNA microarray screening. Gene Ontology (GO) enrichment analysis was conducted to determine the potential functions of piRNAs. Results: Using microarray analysis, we identified a cohort of differentially expressed piRNAs. Fifteen piRNAs, including DQ570763 and DQ597396, were downregulated, and 58 piRNAs were upregulated when compared with those in adherent A2780 and SKOV3 cells (p > 0.05, >2.0, respectively). GO functions of the downregulated piRNAs (DQ570763 and DQ570797) suggest that their roles are commonly associated with the Golgi apparatus. In addition, A2780-SP and SKOV3-SP cells had higher PIWIL3 and PIWIL4 mRNA levels than adherent cells (A2780 and SKOV3). Moreover, we determined, using receiver operating characteristic plot, that the expression level of PIWIL4 was lower in responders than in nonresponders after treatment with platins in patients with ovarian cancer. Finally, in ovarian cancer, PIWIL4 expression was associated with somatic mutations of dynein axonemal heavy chain 2, signal induced proliferation associated 1 like 2, YTH N6-methyladenosine RNA-binding protein 1, TBC1 domain family member 8, and LPS responsive Beige-like anchor protein. Conclusion: Our study showed that PIWI proteins and piRNAs are potential diagnostic and prognostic biomarkers for ovarian cancer.
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Affiliation(s)
- Eun Jung Sohn
- College of Medicine, Pusan National University, Yangsan, Korea
| | - Sae-Ock Oh
- Department of Anatomy, School of Medicine, Pusan National University, Yangsan, Korea
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5
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Post F, Bornberg-Bauer E, Vasseur-Cognet M, Harrison MC. More effective transposon regulation in fertile, long-lived termite queens than in sterile workers. Mol Ecol 2023; 32:369-380. [PMID: 36320186 DOI: 10.1111/mec.16753] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 10/04/2022] [Accepted: 10/07/2022] [Indexed: 11/19/2022]
Abstract
Transposable elements (TEs) are mobile genetic sequences, which can cause the accumulation of genomic damage in the lifetime of an organism. The regulation of TEs, for instance via the piRNA-pathway, is an important mechanism to protect the integrity of genomes, especially in the germ-line where mutations can be transmitted to offspring. In eusocial insects, soma and germ-line are divided among worker and reproductive castes, so one may expect caste-specific differences in TE regulation to exist. To test this, we compared whole-genome levels of repeat element transcription in the fat body of female workers, kings and five different queen stages of the higher termite, Macrotermes natalensis. In this species, queens can live over 20 years, maintaining near maximum reproductive output, while sterile workers only live weeks. We found a strong, positive correlation between TE expression and the expression of neighbouring genes in all castes. However, we found substantially higher TE activity in workers than in reproductives. Furthermore, TE expression did not increase with age in queens, despite a sevenfold increase in overall gene expression, due to a significant upregulation of the piRNA-pathway in 20-year-old queens. Our results suggest a caste- and age-specific regulation of the piRNA-pathway has evolved in higher termites that is analogous to germ-line-specific activity in solitary organisms. In the fat body of these termite queens, an important metabolic tissue for maintaining their extreme longevity and reproductive output, an efficient regulation of TEs likely protects genome integrity, thus further promoting reproductive fitness even at high age.
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Affiliation(s)
- Frederik Post
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Erich Bornberg-Bauer
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Mireille Vasseur-Cognet
- UMR IRD 242, UPEC, CNRS 7618, UPMC 113, INRAE 1392, Paris 7 113, Institute of Ecology and Environmental Sciences of Paris, Bondy, France.,University of Paris-Est, Créteil, France.,INSERM, Paris, France
| | - Mark C Harrison
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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6
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Sammarco I, Pieters J, Salony S, Toman I, Zolotarov G, Lafon Placette C. Epigenetic targeting of transposon relics: beating the dead horses of the genome? Epigenetics 2022; 17:1331-1344. [PMID: 36255200 PMCID: PMC9586680 DOI: 10.1080/15592294.2021.2022066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Transposable elements (TEs) have been seen as selfish genetic elements that can propagate in a host genome. Their propagation success is however hindered by a combination of mechanisms such as mutations, selection, and their epigenetic silencing by the host genome. As a result, most copies of TEs in a given genome are dead relics: their sequence is too degenerated to allow any transposition. Nevertheless, these TE relics often, but not always, remain epigenetically silenced, and if not to prevent transposition anymore, one can wonder the reason for this phenomenon. The mere self-perpetuating loop inherent to epigenetic silencing could alone explain that even when inactive, TE copies remain silenced. Beyond this process, nevertheless, antagonistic selective forces are likely to act on TE relic silencing. Especially, without the benefit of preventing transposition, TE relic silencing may prove deleterious to the host fitness, suggesting that the maintenance of TE relic silencing is the result of a fine, and perhaps case-by-case, evolutionary trade-off between beneficial and deleterious effects. Ultimately, the release of TE relics silencing may provide a 'safe' ground for adaptive epimutations to arise. In this review, we provide an overview of these questions in both plants and animals.
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Affiliation(s)
- Iris Sammarco
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic,Institute of Botany, Czech Academy of Sciences, Pruhonice, Czech Republic
| | - Janto Pieters
- Laboratory of Pollen Biology, Institute of Experimental Botany, Czech Academy of Science, Prague, Czech Republic,Department of Plant Experimental Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Susnata Salony
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - Izabela Toman
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
| | - Grygoriy Zolotarov
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Clément Lafon Placette
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic,CONTACT Clément Lafon Placette Department of Botany, Faculty of Science, Charles University, PragueCZ-128 01, Czech Republic
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7
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Ye X, Yang Y, Zhao C, Xiao S, Sun YH, He C, Xiong S, Zhao X, Zhang B, Lin H, Shi J, Mei Y, Xu H, Fang Q, Wu F, Li D, Ye G. Genomic signatures associated with maintenance of genome stability and venom turnover in two parasitoid wasps. Nat Commun 2022; 13:6417. [PMID: 36302851 PMCID: PMC9613689 DOI: 10.1038/s41467-022-34202-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 10/13/2022] [Indexed: 12/25/2022] Open
Abstract
Parasitoid wasps are rapidly developing as a model for evolutionary biology. Here we present chromosomal genomes of two Anastatus wasps, A. japonicus and A. fulloi, and leverage these genomes to study two fundamental questions-genome size evolution and venom evolution. Anastatus shows a much larger genome than is known among other wasps, with unexpectedly recent bursts of LTR retrotransposons. Importantly, several genomic innovations, including Piwi gene family expansion, ubiquitous Piwi expression profiles, as well as transposable element-piRNA coevolution, have likely emerged for transposable element silencing to maintain genomic stability. Additionally, we show that the co-option evolution arose by expression shifts in the venom gland plays a dominant role in venom turnover. We also highlight the potential importance of non-venom genes that are coexpressed with venom genes during venom evolution. Our findings greatly advance the current understanding of genome size evolution and venom evolution, and these genomic resources will facilitate comparative genomics studies of insects in the future.
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Affiliation(s)
- Xinhai Ye
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China ,grid.13402.340000 0004 1759 700XShanghai Institute for Advanced Study, Zhejiang University, Shanghai, China ,grid.13402.340000 0004 1759 700XCollege of Computer Science and Technology, Zhejiang University, Hangzhou, China
| | - Yi Yang
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Can Zhao
- grid.484195.5Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Shan Xiao
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yu H. Sun
- grid.16416.340000 0004 1936 9174Department of Biology, University of Rochester, Rochester, NY USA
| | - Chun He
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Shijiao Xiong
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Xianxin Zhao
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Bo Zhang
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Haiwei Lin
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Jiamin Shi
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yang Mei
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Hongxing Xu
- grid.410744.20000 0000 9883 3553State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agroproducts, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Qi Fang
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Fei Wu
- grid.13402.340000 0004 1759 700XShanghai Institute for Advanced Study, Zhejiang University, Shanghai, China ,grid.13402.340000 0004 1759 700XCollege of Computer Science and Technology, Zhejiang University, Hangzhou, China
| | - Dunsong Li
- grid.484195.5Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou, China
| | - Gongyin Ye
- grid.13402.340000 0004 1759 700XState Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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Oliveira JIN, Cardoso AL, Wolf IR, de Oliveira RA, Martins C. First characterization of PIWI-interacting RNA clusters in a cichlid fish with a B chromosome. BMC Biol 2022; 20:204. [PMID: 36127679 PMCID: PMC9490952 DOI: 10.1186/s12915-022-01403-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/06/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND B chromosomes are extra elements found in several eukaryote species. Usually, they do not express a phenotype in the host. However, advances in bioinformatics over the last decades have allowed us to describe several genes and molecular functions related to B chromosomes. These advances enable investigations of the relationship between the B chromosome and the host to understand how this element has been preserved in genomes. However, considering that transposable elements (TEs) are highly abundant in this supernumerary chromosome, there is a lack of knowledge concerning the dynamics of TE control in B-carrying cells. Thus, the present study characterized PIWI-interacting RNA (piRNA) clusters and pathways responsible for silencing the mobilization of TEs in gonads of the cichlid fish Astatotilapia latifasciata carrying the B chromosome. RESULTS Through small RNA-seq and genome assembly, we predicted and annotated piRNA clusters in the A. latifasciata genome for the first time. We observed that these clusters had biased expression related to sex and the presence of the B chromosome. Furthermore, three piRNA clusters, named curupira, were identified in the B chromosome. Two of them were expressed exclusively in gonads of samples with the B chromosome. The composition of these curupira sequences was derived from LTR, LINE, and DNA elements, representing old and recent transposition events in the A. latifasciata genome and the B chromosome. The presence of the B chromosome also affected the expression of piRNA pathway genes. The mitochondrial cardiolipin hydrolase-like (pld6) gene is present in the B chromosome, as previously reported, and an increase in its expression was detected in gonads with the B chromosome. CONCLUSIONS Due to the high abundance of TEs in the B chromosome, it was possible to investigate the origin of piRNA from these jumping genes. We hypothesize that the B chromosome has evolved its own genomic guardians to prevent uncontrolled TE mobilization. Furthermore, we also detected an expression bias in the presence of the B chromosome over A. latifasciata piRNA clusters and pathway genes.
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Affiliation(s)
- Jordana Inácio Nascimento Oliveira
- Department of Structural and Functional Biology, Institute of Bioscience at Botucatu, São Paulo State University (UNESP), Botucatu, SP, 18618-689, Brazil
| | - Adauto Lima Cardoso
- Department of Structural and Functional Biology, Institute of Bioscience at Botucatu, São Paulo State University (UNESP), Botucatu, SP, 18618-689, Brazil
| | - Ivan Rodrigo Wolf
- Department of Structural and Functional Biology, Institute of Bioscience at Botucatu, São Paulo State University (UNESP), Botucatu, SP, 18618-689, Brazil
| | - Rogério Antônio de Oliveira
- Department of Biostatistics, Plant Biology, Parasitology and Zoology, Institute of Bioscience at Botucatu, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Cesar Martins
- Department of Structural and Functional Biology, Institute of Bioscience at Botucatu, São Paulo State University (UNESP), Botucatu, SP, 18618-689, Brazil.
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Affiliation(s)
| | - Francisco J. Ruiz-Ruano
- Department of Organismal Biology – Systematic Biology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- School of Biological Sciences, Norwich Research Park University of East Anglia, Norwich, UK
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10
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Banho CA, Oliveira DS, Haudry A, Fablet M, Vieira C, Carareto CMA. Transposable Element Expression and Regulation Profile in Gonads of Interspecific Hybrids of Drosophila arizonae and Drosophila mojavensis wrigleyi. Cells 2021; 10:cells10123574. [PMID: 34944084 PMCID: PMC8700503 DOI: 10.3390/cells10123574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/07/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022] Open
Abstract
Interspecific hybridization may lead to sterility and/or inviability through differential expression of genes and transposable elements (TEs). In Drosophila, studies have reported massive TE mobilization in hybrids from interspecific crosses of species presenting high divergence times. However, few studies have examined the consequences of TE mobilization upon hybridization in recently diverged species, such as Drosophila arizonae and D. mojavensis. We have sequenced transcriptomes of D. arizonae and the subspecies D. m. wrigleyi and their reciprocal hybrids, as well as piRNAs, to analyze the impact of genomic stress on TE regulation. Our results revealed that the differential expression in both gonadal tissues of parental species was similar. Globally, ovaries and testes showed few deregulated TEs compared with both parental lines. Analyses of small RNA data showed that in ovaries, the TE upregulation is likely due to divergence of copies inherited from parental genomes and lack of piRNAs mapping to them. Nevertheless, in testes, the divergent expression of genes associated with chromatin state and piRNA pathway potentially indicates that TE differential expression is related to the divergence of regulatory genes that play a role in modulating transcriptional and post-transcriptional mechanisms.
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Affiliation(s)
- Cecília Artico Banho
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), São José do Rio Preto 15054-000, SP, Brazil; (C.A.B.); (D.S.O.)
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622 Villeurbanne, France; (A.H.); (M.F.)
| | - Daniel Siqueira Oliveira
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), São José do Rio Preto 15054-000, SP, Brazil; (C.A.B.); (D.S.O.)
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622 Villeurbanne, France; (A.H.); (M.F.)
| | - Annabelle Haudry
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622 Villeurbanne, France; (A.H.); (M.F.)
| | - Marie Fablet
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622 Villeurbanne, France; (A.H.); (M.F.)
- Institut Universitaire de France (IUF), F-75231 Paris, France
| | - Cristina Vieira
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, F-69622 Villeurbanne, France; (A.H.); (M.F.)
- Correspondence: (C.V.); (C.M.A.C.)
| | - Claudia Marcia Aparecida Carareto
- Institute of Biosciences, Humanities and Exact Sciences, São Paulo State University (Unesp), São José do Rio Preto 15054-000, SP, Brazil; (C.A.B.); (D.S.O.)
- Correspondence: (C.V.); (C.M.A.C.)
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11
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Drouin M, Hénault M, Hallin J, Landry CR. Testing the Genomic Shock Hypothesis Using Transposable Element Expression in Yeast Hybrids. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:729264. [PMID: 37744137 PMCID: PMC10512236 DOI: 10.3389/ffunb.2021.729264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 07/26/2021] [Indexed: 09/26/2023]
Abstract
Transposable element (TE) insertions are a source of structural variation and can cause genetic instability and gene expression changes. A host can limit the spread of TEs with various repression mechanisms. Many examples of plant and animal interspecific hybrids show disrupted TE repression leading to TE propagation. Recent studies in yeast did not find any increase in transposition rate in hybrids. However, this does not rule out the possibility that the transcriptional or translational activity of TEs increases following hybridization because of a disruption of the host TE control mechanisms. Thus, whether total expression of a TE family is higher in hybrids than in their parental species remains to be examined. We leveraged publically available RNA-seq and ribosomal profiling data on yeast artificial hybrids of the Saccharomyces genus and performed differential expression analysis of their LTR retrotransposons (Ty elements). Our analyses of total mRNA levels show that Ty elements are generally not differentially expressed in hybrids, even when the hybrids are exposed to a low temperature stress condition. Overall, only 2/26 Ty families show significantly higher expression in the S. cerevisiae × S. uvarum hybrids while there are 3/26 showing significantly lower expression in the S. cerevisiae x S. paradoxus hybrids. Our analysis of ribosome profiling data of S. cerevisiae × S. paradoxus hybrids shows similar translation efficiency of Ty in both parents and hybrids, except for Ty1_cer showing higher translation efficiency. Overall, our results do not support the hypothesis that hybridization could act as a systematic trigger of TE expression in yeast and suggest that the impact of hybridization on TE activity is strain and TE specific.
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Affiliation(s)
- Marika Drouin
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Université Laval, Québec, QC, Canada
- PROTEO - Regroupement Québécois de Recherche sur la Fonction, l'Ingénierie et les Applications des Protéines, Québec, QC, Canada
- Centre de Recherche en Données Massives de l'Université Laval, Université Laval, Québec, QC, Canada
| | - Mathieu Hénault
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Université Laval, Québec, QC, Canada
- PROTEO - Regroupement Québécois de Recherche sur la Fonction, l'Ingénierie et les Applications des Protéines, Québec, QC, Canada
- Centre de Recherche en Données Massives de l'Université Laval, Université Laval, Québec, QC, Canada
| | - Johan Hallin
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Université Laval, Québec, QC, Canada
- PROTEO - Regroupement Québécois de Recherche sur la Fonction, l'Ingénierie et les Applications des Protéines, Québec, QC, Canada
- Centre de Recherche en Données Massives de l'Université Laval, Université Laval, Québec, QC, Canada
- Département de Biologie, Université Laval, Québec, QC, Canada
| | - Christian R. Landry
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC, Canada
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Université Laval, Québec, QC, Canada
- PROTEO - Regroupement Québécois de Recherche sur la Fonction, l'Ingénierie et les Applications des Protéines, Québec, QC, Canada
- Centre de Recherche en Données Massives de l'Université Laval, Université Laval, Québec, QC, Canada
- Département de Biologie, Université Laval, Québec, QC, Canada
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12
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Yakovenko I, Agronin J, Smith LC, Oren M. Guardian of the Genome: An Alternative RAG/Transib Co-Evolution Hypothesis for the Origin of V(D)J Recombination. Front Immunol 2021; 12:709165. [PMID: 34394111 PMCID: PMC8355894 DOI: 10.3389/fimmu.2021.709165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/05/2021] [Indexed: 11/13/2022] Open
Abstract
The appearance of adaptive immunity in jawed vertebrates is termed the immunological 'Big Bang' because of the short evolutionary time over which it developed. Underlying it is the recombination activating gene (RAG)-based V(D)J recombination system, which initiates the sequence diversification of the immunoglobulins and lymphocyte antigen receptors. It was convincingly argued that the RAG1 and RAG2 genes originated from a single transposon. The current dogma postulates that the V(D)J recombination system was established by the split of a primordial vertebrate immune receptor gene into V and J segments by a RAG1/2 transposon, in parallel with the domestication of the same transposable element in a separate genomic locus as the RAG recombinase. Here, based on a new interpretation of previously published data, we propose an alternative evolutionary hypothesis suggesting that two different elements, a RAG1/2 transposase and a Transib transposon invader with RSS-like terminal inverted repeats, co-evolved to work together, resulting in a functional recombination process. This hypothesis offers an alternative understanding of the acquisition of recombinase function by RAGs and the origin of the V(D)J system.
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Affiliation(s)
- Iryna Yakovenko
- Department of Molecular Biology, Ariel University, Ariel, Israel
| | - Jacob Agronin
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - L. Courtney Smith
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Matan Oren
- Department of Molecular Biology, Ariel University, Ariel, Israel
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13
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Liu Y, Yuan J, Jia G, Ye W, Jeffrey Chen Z, Song Q. Histone H3K27 dimethylation landscapes contribute to genome stability and genetic recombination during wheat polyploidization. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:678-690. [PMID: 33131144 DOI: 10.1111/tpj.15063] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 05/02/2023]
Abstract
Bread wheat (Triticum aestivum) is an allohexaploid that was formed via two allopolyploidization events. Growing evidence suggests histone modifications are involved in the response to 'genomic shock' and environmental adaptation during polyploid formation and evolution. However, the role of histone modifications, especially histone H3 lysine-27 dimethylation (H3K27me2), in genome evolution remains elusive. Here we analyzed H3K27me2 and H3K27me3 profiles in hexaploid wheat and its tetraploid and diploid relatives. Although H3K27me3 levels were relatively stable among wheat species with different ploidy levels, H3K27me2 intensities increased concurrent with increased ploidy levels, and H3K27me2 peaks were colocalized with massively amplified DTC transposons (CACTA family) in euchromatin, which may silence euchromatic transposons to maintain genome stability during polyploid wheat evolution. Consistently, the distribution of H3K27me2 is mutually exclusive with another repressive histone mark, H3K9me2, that mainly silences transposons in heterochromatic regions. Remarkably, the regions with low H3K27me2 levels (named H3K27me2 valleys) were associated with the formation of DNA double-strand breaks in genomes of wheat, maize (Zea mays) and Arabidopsis. Our results provide a comprehensive view of H3K27me2 and H3K27me3 distributions during wheat evolution, which support roles for H3K27me2 in silencing euchromatic transposons to maintain genome stability and in modifying genetic recombination landscapes. These genomic insights may empower breeding improvement of crops.
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Affiliation(s)
- Yanfeng Liu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Jingya Yuan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Guanghong Jia
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Wenxue Ye
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
| | - Z Jeffrey Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Qingxin Song
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, No. 1 Weigang, Nanjing, Jiangsu, 210095, China
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14
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Padeken J, Methot S, Zeller P, Delaney CE, Kalck V, Gasser SM. Argonaute NRDE-3 and MBT domain protein LIN-61 redundantly recruit an H3K9me3 HMT to prevent embryonic lethality and transposon expression. Genes Dev 2021; 35:82-101. [PMID: 33303642 PMCID: PMC7778263 DOI: 10.1101/gad.344234.120] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/05/2020] [Indexed: 12/30/2022]
Abstract
The establishment and maintenance of chromatin domains shape the epigenetic memory of a cell, with the methylation of histone H3 lysine 9 (H3K9me) defining transcriptionally silent heterochromatin. We show here that the C. elegans SET-25 (SUV39/G9a) histone methyltransferase (HMT), which catalyzes H3K9me1, me2 and me3, can establish repressed chromatin domains de novo, unlike the SETDB1 homolog MET-2. Thus, SET-25 is needed to silence novel insertions of RNA or DNA transposons, and repress tissue-specific genes de novo during development. We identify two partially redundant pathways that recruit SET-25 to its targets. One pathway requires LIN-61 (L3MBTL2), which uses its four MBT domains to bind the H3K9me2 deposited by MET-2. The second pathway functions independently of MET-2 and involves the somatic Argonaute NRDE-3 and small RNAs. This pathway targets primarily highly conserved RNA and DNA transposons. These redundant SET-25 targeting pathways (MET-2-LIN-61-SET-25 and NRDE-3-SET-25) ensure repression of intact transposons and de novo insertions, while MET-2 can act alone to repress simple and satellite repeats. Removal of both pathways in the met-2;nrde-3 double mutant leads to the loss of somatic H3K9me2 and me3 and the synergistic derepression of transposons in embryos, strongly elevating embryonic lethality.
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Affiliation(s)
- Jan Padeken
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Stephen Methot
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Peter Zeller
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
- Faculty of Natural Sciences, University of Basel, CH-4056 Basel, Switzerland
| | - Colin E Delaney
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Veronique Kalck
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland
- Faculty of Natural Sciences, University of Basel, CH-4056 Basel, Switzerland
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15
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Carleton KL, Conte MA, Malinsky M, Nandamuri SP, Sandkam BA, Meier JI, Mwaiko S, Seehausen O, Kocher TD. Movement of transposable elements contributes to cichlid diversity. Mol Ecol 2020; 29:4956-4969. [PMID: 33049090 DOI: 10.1111/mec.15685] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/02/2020] [Accepted: 10/05/2020] [Indexed: 12/11/2022]
Abstract
African cichlid fishes are a prime model for studying speciation mechanisms. Despite the development of extensive genomic resources, it has been difficult to determine which sources of genetic variation are responsible for cichlid phenotypic variation. One of their most variable phenotypes is visual sensitivity, with some of the largest spectral shifts among vertebrates. These shifts arise primarily from differential expression of seven cone opsin genes. By mapping expression quantitative trait loci (eQTL) in intergeneric crosses of Lake Malawi cichlids, we previously identified four causative genetic variants that correspond to indels in the promoters of either key transcription factors or an opsin gene. In this comprehensive study, we show that these indels are the result of the movement of transposable elements (TEs) that correlate with opsin expression variation across the Malawi flock. In tracking the evolutionary history of these particular indels, we found they are endemic to Lake Malawi, suggesting that these TEs are recently active and are segregating within the Malawi cichlid lineage. However, an independent indel has arisen at a similar genomic location in one locus outside of the Malawi flock. The convergence in TE movement suggests these loci are primed for TE insertion and subsequent deletions. Increased TE mobility may be associated with interspecific hybridization, which disrupts mechanisms of TE suppression. This might provide a link between cichlid hybridization and accelerated regulatory variation. Overall, our study suggests that TEs may be an important driver of key regulatory changes, facilitating rapid phenotypic change and possibly speciation in African cichlids.
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Affiliation(s)
- Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Matthew A Conte
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Milan Malinsky
- Wellcome Sanger Institute, Cambridge, UK.,Zoological Institute, University of Basel, Basel, Switzerland
| | | | | | - Joana I Meier
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.,Computational and Molecular Population Genetics Laboratory, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Salome Mwaiko
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Ole Seehausen
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Thomas D Kocher
- Department of Biology, University of Maryland, College Park, MD, USA
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16
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Gamez S, Srivastav S, Akbari OS, Lau NC. Diverse Defenses: A Perspective Comparing Dipteran Piwi-piRNA Pathways. Cells 2020; 9:E2180. [PMID: 32992598 PMCID: PMC7601171 DOI: 10.3390/cells9102180] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 02/07/2023] Open
Abstract
Animals face the dual threat of virus infections hijacking cellular function and transposons proliferating in germline genomes. For insects, the deeply conserved RNA interference (RNAi) pathways and other chromatin regulators provide an important line of defense against both viruses and transposons. For example, this innate immune system displays adaptiveness to new invasions by generating cognate small RNAs for targeting gene silencing measures against the viral and genomic intruders. However, within the Dipteran clade of insects, Drosophilid fruit flies and Culicids mosquitoes have evolved several unique mechanistic aspects of their RNAi defenses to combat invading transposons and viruses, with the Piwi-piRNA arm of the RNAi pathways showing the greatest degree of novel evolution. Whereas central features of Piwi-piRNA pathways are conserved between Drosophilids and Culicids, multiple lineage-specific innovations have arisen that may reflect distinct genome composition differences and specific ecological and physiological features dividing these two branches of Dipterans. This perspective review focuses on the most recent findings illuminating the Piwi/piRNA pathway distinctions between fruit flies and mosquitoes, and raises open questions that need to be addressed in order to ameliorate human diseases caused by pathogenic viruses that mosquitoes transmit as vectors.
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Affiliation(s)
- Stephanie Gamez
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Satyam Srivastav
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA;
| | - Omar S. Akbari
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, CA 92093, USA; (S.G.); (O.S.A.)
| | - Nelson C. Lau
- Department of Biochemistry and Genome Science Institute, Boston University School of Medicine, Boston, MA 02118, USA
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17
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Li X, Wang X, Cheng Z, Zhu Q. AGO2 and its partners: a silencing complex, a chromatin modulator, and new features. Crit Rev Biochem Mol Biol 2020; 55:33-53. [DOI: 10.1080/10409238.2020.1738331] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xiaojing Li
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Xueying Wang
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Zeneng Cheng
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
| | - Qubo Zhu
- Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, China
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18
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Luo S, Zhang H, Duan Y, Yao X, Clark AG, Lu J. The evolutionary arms race between transposable elements and piRNAs in Drosophila melanogaster. BMC Evol Biol 2020; 20:14. [PMID: 31992188 PMCID: PMC6988346 DOI: 10.1186/s12862-020-1580-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Accepted: 01/13/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The piwi-interacting RNAs (piRNAs) are small non-coding RNAs that specifically repress transposable elements (TEs) in the germline of Drosophila. Despite our expanding understanding of TE:piRNA interaction, whether there is an evolutionary arms race between TEs and piRNAs was unclear. RESULTS Here, we studied the population genomics of TEs and piRNAs in the worldwide strains of D. melanogaster. By conducting a correlation analysis between TE contents and the abundance of piRNAs from ovaries of representative strains of D. melanogaster, we find positive correlations between TEs and piRNAs in six TE families. Our simulations further highlight that TE activities and the strength of purifying selection against TEs are important factors shaping the interactions between TEs and piRNAs. Our studies also suggest that the de novo generation of piRNAs is an important mechanism to repress the newly invaded TEs. CONCLUSIONS Our results revealed the existence of an evolutionary arms race between the copy numbers of TEs and the abundance of antisense piRNAs at the population level. Although the interactions between TEs and piRNAs are complex and many factors should be considered to impact their interaction dynamics, our results suggest the emergence, repression specificity and strength of piRNAs on TEs should be considered in studying the landscapes of TE insertions in Drosophila. These results deepen our understanding of the interactions between piRNAs and TEs, and also provide novel insights into the nature of genomic conflicts of other forms.
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Affiliation(s)
- Shiqi Luo
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, College of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- College of Plant Protection, Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100193, China
| | - Hong Zhang
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, College of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Yuange Duan
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, College of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Xinmin Yao
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, College of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA.
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, College of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
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19
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Wu C, Lu J. Diversification of Transposable Elements in Arthropods and Its Impact on Genome Evolution. Genes (Basel) 2019; 10:genes10050338. [PMID: 31064091 PMCID: PMC6562904 DOI: 10.3390/genes10050338] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/09/2019] [Accepted: 04/26/2019] [Indexed: 12/22/2022] Open
Abstract
Transposable elements (TEs) are ubiquitous in arthropods. However, analyses of large-scale and long-term coevolution between TEs and host genomes remain scarce in arthropods. Here, we choose 14 representative Arthropoda species from eight orders spanning more than 500 million years of evolution. By developing an unbiased TE annotation pipeline, we obtained 87 to 2266 TE reference sequences in a species, which is a considerable improvement compared to the reference TEs previously annotated in Repbase. We find that TE loads are diversified among species and were previously underestimated. The highly species- and time-specific expansions and contractions, and intraspecific sequence diversification are the leading driver of long terminal repeat (LTR) dynamics in Lepidoptera. Terminal inverted repeats (TIRs) proliferated substantially in five species with large genomes. A phylogenetic comparison reveals that the loads of multiple TE subfamilies are positively correlated with genome sizes. We also identified a few horizontally transferred TE candidates across nine species. In addition, we set up the Arthropod Transposable Elements database (ArTEdb) to provide TE references and annotations. Collectively, our results provide high-quality TE references and uncover that TE loads and expansion histories vary greatly among arthropods, which implies that TEs are an important driving force shaping the evolution of genomes through gain and loss.
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Affiliation(s)
- Changcheng Wu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing 100871, China.
| | - Jian Lu
- State Key Laboratory of Protein and Plant Gene Research, Center for Bioinformatics, School of Life Sciences, Peking University, Beijing 100871, China.
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20
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The Function of Non-Coding RNAs in Lung Cancer Tumorigenesis. Cancers (Basel) 2019; 11:cancers11050605. [PMID: 31052265 PMCID: PMC6563001 DOI: 10.3390/cancers11050605] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/18/2019] [Accepted: 04/25/2019] [Indexed: 01/08/2023] Open
Abstract
Lung cancer is the most prevalent and deadliest cancer worldwide. A significant part of lung cancer studies is dedicated to the expression alterations of non-coding RNAs. The non-coding RNAs are transcripts that cannot be translated into proteins. While the study of microRNAs and siRNAs in lung cancer received a lot of attention over the last decade, highly efficient therapeutic option or the diagnostic methods based on non-coding RNAs are still lacking. Because of this, it is of utmost importance to direct future research on lung cancer towards analyzing other RNA types for which the currently available data indicates that are essential at modulating lung tumorigenesis. Through our review of studies on this subject, we identify the following non-coding RNAs as tumor suppressors: ts-46, ts-47, ts-101, ts-53, ts-3676, ts-4521 (tRNA fragments), SNORD116-26, HBII-420, SNORD15A, SNORA42 (snoRNAs), piRNA-like-163, piR-35127, the piR-46545 (piRNAs), CHIAP2, LOC100420907, RPL13AP17 (pseudogenes), and uc.454 (T-UCR). We also found non-coding RNAs with tumor-promoting function: tRF-Leu-CAG, tRNA-Leu, tRNA-Val (tRNA fragments), circ-RAD23B, circRNA 100146, circPVT1, circFGFR3, circ_0004015, circPUM1, circFLI1, circABCB10, circHIPK3 (circRNAs), SNORA42, SNORA3, SNORD46, SNORA21, SNORD28, SNORA47, SNORD66, SNORA68, SNORA78 (snoRNAs), piR-65, piR-34871, piR-52200, piR651 (piRNAs), hY4 5’ fragments (YRNAs), FAM83A-AS1, WRAP53, NKX2-1-AS1 (NATs), DUXAP8, SFTA1P (pseudogene transcripts), uc.338, uc.339 (T-UCRs), and hTERC.
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21
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Guio L, González J. New Insights on the Evolution of Genome Content: Population Dynamics of Transposable Elements in Flies and Humans. Methods Mol Biol 2019; 1910:505-530. [PMID: 31278675 DOI: 10.1007/978-1-4939-9074-0_16] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Understanding the abundance, diversity, and distribution of TEs in genomes is crucial to understand genome structure, function, and evolution. Advances in whole-genome sequencing techniques, as well as in bioinformatics tools, have increased our ability to detect and analyze the transposable element content in genomes. In addition to reference genomes, we now have access to population datasets in which multiple individuals within a species are sequenced. In this chapter, we highlight the recent advances in the study of TE population dynamics focusing on fruit flies and humans, which represent two extremes in terms of TE abundance, diversity, and activity. We review the most recent methodological approaches applied to the study of TE dynamics as well as the new knowledge on host factors involved in the regulation of TE activity. In addition to transposition rates, we also focus on TE deletion rates and on the selective forces that affect the dynamics of TEs in genomes.
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Affiliation(s)
- Lain Guio
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain
| | - Josefa González
- Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Barcelona, Spain.
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Juarez-Carreño S, Morante J, Dominguez M. Systemic signalling and local effectors in developmental stability, body symmetry, and size. Cell Stress 2018; 2:340-361. [PMID: 31225459 PMCID: PMC6551673 DOI: 10.15698/cst2018.12.167] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Symmetric growth and the origins of fluctuating asymmetry are unresolved phenomena of biology. Small, and sometimes noticeable, deviations from perfect bilateral symmetry reflect the vulnerability of development to perturbations. The degree of asymmetry is related to the magnitude of the perturbations and the ability of an individual to cope with them. As the left and right sides of an individual were presumed to be genetically identical, deviations of symmetry were traditionally attributed to non-genetic effects such as environmental and developmental noise. In this review, we draw attention to other possible sources of variability, especially to somatic mutations and transposons. Mutations are a major source of phenotypic variability and recent genomic data have highlighted somatic mutations as ubiquitous, even in phenotypically normal individuals. We discuss the importance of factors that are responsible for buffering and stabilizing the genome and for maintaining size robustness and quality through elimination of less-fit or damaged cells. However, the important question that arises from these studies is whether this self-correcting capacity and intrinsic organ size controls are sufficient to explain how symmetric structures can reach an identical size and shape. Indeed, recent discoveries in the fruit fly have uncovered a conserved hormone of the insulin/IGF/relaxin family, Dilp8, that is responsible for stabilizing body size and symmetry in the face of growth perturbations. Dilp8 alarm signals periphery growth status to the brain, where it acts on its receptor Lgr3. Loss of Dilp8-Lgr3 signaling renders flies incapable of detecting growth perturbations and thus maintaining a stable size and symmetry. These findings help to understand how size and symmetry of somatic tissues remain undeterred in noisy environments, after injury or illnesses, and in the presence of accumulated somatic mutations.
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Affiliation(s)
- Sergio Juarez-Carreño
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
| | - Javier Morante
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
| | - Maria Dominguez
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Avda Santiago Ramón y Cajal s/n, Campus de Sant Joan, Alicante, Spain
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23
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Meki IK, İnce İA, Kariithi HM, Boucias DG, Ozcan O, Parker AG, Vlak JM, van Oers MM, Abd-Alla AMM. Expression Profile of Glossina pallidipes MicroRNAs During Symptomatic and Asymptomatic Infection With Glossina pallidipes Salivary Gland Hypertrophy Virus (Hytrosavirus). Front Microbiol 2018; 9:2037. [PMID: 30233523 PMCID: PMC6129597 DOI: 10.3389/fmicb.2018.02037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 08/13/2018] [Indexed: 01/01/2023] Open
Abstract
The Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) infects tsetse flies predominantly asymptomatically and occasionally symptomatically. Symptomatic infections are characterized by overt salivary gland hypertrophy (SGH) in mass reared tsetse flies, which causes reproductive dysfunctions and colony collapse, thus hindering tsetse control via sterile insect technique (SIT). Asymptomatic infections have no apparent cost to the fly's fitness. Here, small RNAs were sequenced and profiles in asymptomatically and symptomatically infected G. pallidipes flies determined. Thirty-eight host-encoded microRNAs (miRNAs) were present in both the asymptomatic and symptomatic fly profiles, while nine host miRNAs were expressed specifically in asymptomatic flies versus 10 in symptomatic flies. Of the shared 38 miRNAs, 15 were differentially expressed when comparing asymptomatic with symptomatic flies. The most up-regulated host miRNAs in symptomatic flies was predicted to target immune-related mRNAs of the host. Six GpSGHV-encoded miRNAs were identified, of which five of them were only in symptomatic flies. These virus-encoded miRNAs may not only target host immune genes but may also participate in viral immune evasion. This evidence of differential host miRNA profile in Glossina in symptomatic flies advances our understanding of the GpSGHV-Glossina interactions and provides potential new avenues, for instance by utilization of particular miRNA inhibitors or mimics to better manage GpSGHV infections in tsetse mass-rearing facilities, a prerequisite for successful SIT implementation.
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Affiliation(s)
- Irene K. Meki
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
- Laboratory of Virology, Wageningen University and Research, Wageningen, Netherlands
| | - İkbal A. İnce
- Department of Medical Microbiology, School of Medicine, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey
- Department of Biostatistics and Medical Informatics, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Henry M. Kariithi
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Drion G. Boucias
- Entomology and Nematology Department, University of Florida, Gainesville, FL, United States
| | - Orhan Ozcan
- Department of Biostatistics and Medical Informatics, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey
| | - Andrew G. Parker
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - Just M. Vlak
- Laboratory of Virology, Wageningen University and Research, Wageningen, Netherlands
| | - Monique M. van Oers
- Laboratory of Virology, Wageningen University and Research, Wageningen, Netherlands
| | - Adly M. M. Abd-Alla
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
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24
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Song MJ, Schaack S. Evolutionary Conflict between Mobile DNA and Host Genomes. Am Nat 2018; 192:263-273. [DOI: 10.1086/698482] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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25
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Ponrathnam T, Mishra RK. From chromosomes to genomes: new insights with emerging techniques. THE NUCLEUS 2018. [DOI: 10.1007/s13237-018-0242-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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26
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A novel miRNA, miR-13664, targets CpCYP314A1 to regulate deltamethrin resistance in Culex pipiens pallens. Parasitology 2018; 146:197-205. [PMID: 29966536 DOI: 10.1017/s0031182018001002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Extensive insecticide use has led to the resistance of mosquitoes to these insecticides, posing a major barrier to mosquito control. Previous Solexa high-throughput sequencing of Culex pipiens pallens in the laboratory has revealed that the abundance of a novel microRNA (miRNA), miR-13664, was higher in a deltamethrin-sensitive (DS) strain than a deltamethrin-resistant (DR) strain. Real-time quantitative PCR revealed that the miR-13664 transcript level was lower in the DR strain than in the DS strain. MiR-13664 oversupply in the DR strain increased the susceptibility of these mosquitoes to deltamethrin, whereas inhibition of miR-13664 made the DS strain more resistant to deltamethrin. Results of bioinformatic analysis, quantitative reverse-transcriptase polymerase chain reaction, luciferase assay and miR mimic/inhibitor microinjection revealed CpCYP314A1 to be a target of miR-13664. In addition, downregulation of CpCYP314A1 expression in the DR strain reduced the resistance of mosquitoes to deltamethrin. Taken together, our results indicate that miR-13664 could regulate deltamethrin resistance by interacting with CpCYP314A1, providing new insights into mosquito resistance mechanisms.
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Serrato-Capuchina A, Matute DR. The Role of Transposable Elements in Speciation. Genes (Basel) 2018; 9:E254. [PMID: 29762547 PMCID: PMC5977194 DOI: 10.3390/genes9050254] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/26/2018] [Accepted: 04/26/2018] [Indexed: 01/20/2023] Open
Abstract
Understanding the phenotypic and molecular mechanisms that contribute to genetic diversity between and within species is fundamental in studying the evolution of species. In particular, identifying the interspecific differences that lead to the reduction or even cessation of gene flow between nascent species is one of the main goals of speciation genetic research. Transposable elements (TEs) are DNA sequences with the ability to move within genomes. TEs are ubiquitous throughout eukaryotic genomes and have been shown to alter regulatory networks, gene expression, and to rearrange genomes as a result of their transposition. However, no systematic effort has evaluated the role of TEs in speciation. We compiled the evidence for TEs as potential causes of reproductive isolation across a diversity of taxa. We find that TEs are often associated with hybrid defects that might preclude the fusion between species, but that the involvement of TEs in other barriers to gene flow different from postzygotic isolation is still relatively unknown. Finally, we list a series of guides and research avenues to disentangle the effects of TEs on the origin of new species.
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Affiliation(s)
- Antonio Serrato-Capuchina
- Biology Department, Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27514, USA.
| | - Daniel R Matute
- Biology Department, Genome Sciences Building, University of North Carolina, Chapel Hill, NC 27514, USA.
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28
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Lakhotia SC. Non-coding RNAs demystify constitutive heterochromatin as essential modulator of epigenotype. THE NUCLEUS 2017. [DOI: 10.1007/s13237-017-0221-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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29
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Castillejo-López C, Cai X, Fahmy K, Baumgartner S. Drosophila exoribonuclease nibbler is a tumor suppressor, acts within the RNA i machinery and is not enriched in the nuage during early oogenesis. Hereditas 2017; 155:12. [PMID: 28974923 PMCID: PMC5622571 DOI: 10.1186/s41065-017-0047-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/11/2017] [Indexed: 01/07/2023] Open
Abstract
Background micro RNAs (miRNAs) are important regulators of many biological pathways. A plethora of steps are required to form, from a precursor, the mature miRNA that eventually acts on its target RNA to repress its expression or to inhibit translation. Recently, Drosophila nibbler (nbr) has been shown to be an important player in the maturation process of miRNA and piRNA. Nbr is an exoribonuclease which helps to shape the 3′ end of miRNAs by trimming the 3′ overhang to a final length. Results In contrast to previous reports on the localization of Nbr, we report that 1) Nbr is expressed only during a short time of oogenesis and appears ubiquitously localized within oocytes, and that 2) Nbr was is not enriched in the nuage where it was shown to be involved in piwi-mediated mechanisms. To date, there is little information available on the function of nbr for cellular and developmental processes. Due to the fact that nbr mutants are viable with minor deleterious effects, we used the GAL4/UAS over-expression system to define novel functions of nbr. We disclose hitherto unknown functions of nbr 1) as a tumor suppressor and 2) as a suppressor of RNAi. Finally, we confirm that nbr is a suppressor of transposon activity. Conclusions Our data suggest that nbr exerts much more widespread functions than previously reported from trimming 3′ ends of miRNAs only.
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Affiliation(s)
- Casimiro Castillejo-López
- Department of Experimental Medical Science, Lund University, BMC D10, 22184 Lund, Sweden.,Present address: Department of Molecular Epidemiology, Uppsala University, 75185 Uppsala, Sweden
| | - Xiaoli Cai
- Department of Experimental Medical Science, Lund University, BMC D10, 22184 Lund, Sweden
| | - Khalid Fahmy
- Department of Experimental Medical Science, Lund University, BMC D10, 22184 Lund, Sweden.,Present address: Department of Genetics, Ain Shams University, Cairo, Egypt
| | - Stefan Baumgartner
- Department of Experimental Medical Science, Lund University, BMC D10, 22184 Lund, Sweden
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