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Khajouei S, Hosseinzadeh E, Ravan H, Mohammadi A. Binary detection of protein and nucleic acid enabled cancer diagnosis through branched hybridization chain reaction. Anal Chim Acta 2022; 1205:339755. [DOI: 10.1016/j.aca.2022.339755] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 03/19/2022] [Accepted: 03/21/2022] [Indexed: 12/12/2022]
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2
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He ZC, Liu Q, Yang KD, Chen C, Zhang XN, Wang WY, Zeng H, Wang B, Liu YQ, Luo M, Li L, Niu Q, Lu HM, Luo T, Yao XH, Guo HT, Ji JL, Cao MF, Shi Y, Ping YF, Bian XW. HOXA5 is amplified in glioblastoma stem cells and promotes tumor progression by transcriptionally activating PTPRZ1. Cancer Lett 2022; 533:215605. [DOI: 10.1016/j.canlet.2022.215605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/10/2022] [Accepted: 02/21/2022] [Indexed: 01/23/2023]
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3
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Duk MA, Gursky VV, Samsonova MG, Surkova SY. Application of Domain- and Genotype-Specific Models to Infer Post-Transcriptional Regulation of Segmentation Gene Expression in Drosophila. Life (Basel) 2021; 11:life11111232. [PMID: 34833107 PMCID: PMC8618293 DOI: 10.3390/life11111232] [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: 09/24/2021] [Revised: 11/05/2021] [Accepted: 11/10/2021] [Indexed: 11/16/2022] Open
Abstract
Unlike transcriptional regulation, the post-transcriptional mechanisms underlying zygotic segmentation gene expression in early Drosophila embryo have been insufficiently investigated. Condition-specific post-transcriptional regulation plays an important role in the development of many organisms. Our recent study revealed the domain- and genotype-specific differences between mRNA and the protein expression of Drosophila hb, gt, and eve genes in cleavage cycle 14A. Here, we use this dataset and the dynamic mathematical model to recapitulate protein expression from the corresponding mRNA patterns. The condition-specific nonuniformity in parameter values is further interpreted in terms of possible post-transcriptional modifications. For hb expression in wild-type embryos, our results predict the position-specific differences in protein production. The protein synthesis rate parameter is significantly higher in hb anterior domain compared to the posterior domain. The parameter sets describing Gt protein dynamics in wild-type embryos and Kr mutants are genotype-specific. The spatial discrepancy between gt mRNA and protein posterior expression in Kr mutants is well reproduced by the whole axis model, thus rejecting the involvement of post-transcriptional mechanisms. Our models fail to describe the full dynamics of eve expression, presumably due to its complex shape and the variable time delays between mRNA and protein patterns, which likely require a more complex model. Overall, our modeling approach enables the prediction of regulatory scenarios underlying the condition-specific differences between mRNA and protein expression in early embryo.
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Affiliation(s)
- Maria A. Duk
- Mathematical Biology and Bioinformatics Laboratory, Peter the Great Saint Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (M.A.D.); (M.G.S.)
- Theoretical Department, Ioffe Institute, 194021 St. Petersburg, Russia;
| | - Vitaly V. Gursky
- Theoretical Department, Ioffe Institute, 194021 St. Petersburg, Russia;
| | - Maria G. Samsonova
- Mathematical Biology and Bioinformatics Laboratory, Peter the Great Saint Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (M.A.D.); (M.G.S.)
| | - Svetlana Yu. Surkova
- Mathematical Biology and Bioinformatics Laboratory, Peter the Great Saint Petersburg Polytechnic University, 195251 St. Petersburg, Russia; (M.A.D.); (M.G.S.)
- Correspondence:
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4
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Simultaneous Detection of Drug-Induced Liver Injury Protein and microRNA Biomarkers Using Dynamic Chemical Labelling on a Luminex MAGPIX System. ANALYTICA 2021. [DOI: 10.3390/analytica2040013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Drug-induced liver injury (DILI) is a potentially fatal adverse event and a leading cause for pre- and post-marketing drug withdrawal. Several multinational DILI initiatives have now recommended a panel of protein and microRNA (miRNA) biomarkers that can detect early liver injury and inform about mechanistic basis. This manuscript describes the development of seqCOMBO, a unique combo-multiplexed assay which combines the dynamic chemical labelling approach and an antibody-dependant method on the Luminex MAGPIX system. SeqCOMBO enables a versatile multiplexing platform to perform qualitative and quantitative analysis of proteins and miRNAs in patient serum samples simultaneously. To the best of our knowledge, this is the first method to profile protein and miRNA biomarkers to diagnose DILI in a single-step assay.
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5
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iPLA2-VIA is required for healthy aging of neurons, muscle, and the female germline in Drosophila melanogaster. PLoS One 2021; 16:e0256738. [PMID: 34506510 PMCID: PMC8432841 DOI: 10.1371/journal.pone.0256738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 08/13/2021] [Indexed: 11/19/2022] Open
Abstract
Neurodegenerative disease (ND) is a growing health burden worldwide, but its causes and treatments remain elusive. Although most cases of ND are sporadic, rare familial cases have been attributed to single genes, which can be investigated in animal models. We have generated a new mutation in the calcium-independent phospholipase A2 (iPLA2) VIA gene CG6718, the Drosophila melanogaster ortholog of human PLA2G6/PARK14, mutations in which cause a suite of NDs collectively called PLA2G6-associated neurodegeneration (PLAN). Our mutants display age-related loss of climbing ability, a symptom of neurodegeneration in flies. Although phospholipase activity commonly is presumed to underlie iPLA2-VIA function, locomotor decline in our mutants is rescued by a transgene carrying a serine-to-alanine mutation in the catalytic residue, suggesting that important functional aspects are independent of phospholipase activity. Additionally, we find that iPLA2-VIA knockdown in either muscle or neurons phenocopies locomotor decline with age, demonstrating its necessity in both neuronal and non-neuronal tissues. Furthermore, RNA in situ hybridization shows high endogenous iPLA2-VIA mRNA expression in adult germ cells, and transgenic HA-tagged iPLA2-VIA colocalizes with mitochondria there. Mutant males are fertile with normal spermatogenesis, while fertility is reduced in mutant females. Mutant female germ cells display age-related mitochondrial aggregation, loss of mitochondrial potential, and elevated cell death. These results suggest that iPLA2-VIA is critical for mitochondrial integrity in the Drosophila female germline, which may provide a novel context to investigate its functions with parallels to PLAN.
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6
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Tortoriello G, Beiersdorf J, Romani S, Williams G, Cameron GA, Mackie K, Williams MJ, Di Marzo V, Keimpema E, Doherty P, Harkany T. Genetic Manipulation of sn-1-Diacylglycerol Lipase and CB 1 Cannabinoid Receptor Gain-of-Function Uncover Neuronal 2-Linoleoyl Glycerol Signaling in Drosophila melanogaster. Cannabis Cannabinoid Res 2021; 6:119-136. [PMID: 33912677 DOI: 10.1089/can.2020.0010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Introduction: In mammals, sn-1-diacylglycerol lipases (DAGL) generate 2-arachidonoylglycerol (2-AG) that, as the major endocannabinoid, modulates synaptic neurotransmission by acting on CB1 cannabinoid receptors (CB1R). Even though the insect genome codes for inaE, which is a DAGL ortholog (dDAGL), its products and their functions remain unknown particularly because insects lack chordate-type cannabinoid receptors. Materials and Methods: Gain-of-function and loss-of-function genetic manipulations were carried out in Drosophila melanogaster, including the generation of both dDAGL-deficient and mammalian CB1R-overexpressing flies. Neuroanatomy, dietary manipulations coupled with targeted mass spectrometry determination of arachidonic acid and 2-linoleoyl glycerol (2-LG) production, behavioral assays, and signal transduction profiling for Akt and Erk kinases were employed. Findings from Drosophilae were validated by a CB1R-binding assay for 2-LG in mammalian cortical homogenates with functionality confirmed in neurons using high-throughput real-time imaging in vitro. Results: In this study, we show that dDAGL is primarily expressed in the brain and nerve cord of Drosophila during larval development and in adult with 2-LG being its chief product as defined by dietary precursor availability. Overexpression of the human CB1R in the ventral nerve cord compromised the mobility of adult Drosophilae. The causality of 2-LG signaling to CB1R-induced behavioral impairments was shown by inaE inactivation normalizing defunct motor coordination. The 2-LG-induced activation of transgenic CB1Rs affected both Akt and Erk kinase cascades by paradoxical signaling. Data from Drosophila models were substantiated by showing 2-LG-mediated displacement of [3H]CP 55,940 in mouse cortical homogenates and reduced neurite extension and growth cone collapsing responses in cultured mouse neurons. Conclusions: Overall, these results suggest that 2-LG is an endocannabinoid-like signal lipid produced by dDAGL in Drosophila.
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Affiliation(s)
- Giuseppe Tortoriello
- Department of Neuroscience, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Johannes Beiersdorf
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Susana Romani
- Wolfson Center for Age-Related Diseases, King's College London, London, United Kingdom
| | - Gareth Williams
- Wolfson Center for Age-Related Diseases, King's College London, London, United Kingdom
| | - Gary A Cameron
- School of Applied Medicine and Dentistry, University of Aberdeen, Aberdeen, United Kingdom
| | - Ken Mackie
- Gill Center for Biomolecular Science, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | | | - Vincenzo Di Marzo
- Endocannabinoid Research Group, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Pozzuoli, Italy.,Canada Excellence Research Chair, Institut Universitaire de Cardiologie et de Pneumologie de Québec and Institut sur la Nutrition et les Aliments Fonctionnels, Université Laval, Québec, Canada
| | - Erik Keimpema
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Patrick Doherty
- Wolfson Center for Age-Related Diseases, King's College London, London, United Kingdom
| | - Tibor Harkany
- Department of Neuroscience, Biomedicum, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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7
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The color pattern inducing gene wingless is expressed in specific cell types of campaniform sensilla of a polka-dotted fruit fly, Drosophila guttifera. Dev Genes Evol 2021; 231:85-93. [PMID: 33774724 DOI: 10.1007/s00427-021-00674-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/15/2021] [Indexed: 12/16/2022]
Abstract
A polka-dotted fruit fly, Drosophila guttifera, has a unique pigmentation pattern on its wings and is used as a model for evo-devo studies exploring the mechanism of evolutionary gain of novel traits. In this species, a morphogen-encoding gene, wingless, is expressed in species-specific positions and induces a unique pigmentation pattern. To produce some of the pigmentation spots on wing veins, wingless is thought to be expressed in developing campaniform sensillum cells, but it was unknown which of the four cell types there express(es) wingless. Here we show that two of the cell types, dome cells and socket cells, express wingless, as indicated by in situ hybridization together with immunohistochemistry. This is a unique case in which non-neuronal SOP (sensory organ precursor) progeny cells produce Wingless as an inducer of pigmentation pattern formation. Our finding opens a path to clarifying the mechanism of evolutionary gain of a unique wingless expression pattern by analyzing gene regulation in dome cells and socket cells.
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8
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Clark-Hachtel C, Fernandez-Nicolas A, Belles X, Tomoyasu Y. Tergal and pleural wing-related tissues in the German cockroach and their implication to the evolutionary origin of insect wings. Evol Dev 2021; 23:100-116. [PMID: 33503322 DOI: 10.1111/ede.12372] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 01/03/2023]
Abstract
The acquisition of wings has facilitated the massive evolutionary success of pterygotes (winged insects), which now make up nearly three-quarters of described metazoans. However, our understanding of how this crucial structure has evolved remains quite elusive. Historically, two ideas have dominated in the wing origin debate, one placing the origin in the dorsal body wall (tergum) and the other in the lateral pleural plates and the branching structures associated with these plates. Through studying wing-related tissues in the wingless segments (such as wing serial homologs) of the beetle, Tribolium castaneum, we obtained several crucial pieces of evidence that support a third idea, the dual origin hypothesis, which proposes that wings evolved from a combination of tergal and pleural tissues. Here, we extended our analysis outside of the beetle lineage and sought to identify wing-related tissues from the wingless segments of the cockroach, Blattella germanica. Through detailed functional and expression analyses for a critical wing gene, vestigial (vg), along with re-evaluating the homeotic transformation of a wingless segment induced by an improved RNA interference protocol, we demonstrate that B. germanica possesses two distinct tissues in their wingless segments, one with tergal and one with pleural nature, that might be evolutionarily related to wings. This outcome appears to parallel the reports from other insects, which may further support a dual origin of insect wings. However, we also identified a vg-independent tissue that contributes to wing formation upon homeotic transformation, as well as vg-dependent tissues that do not appear to participate in wing formation, in B. germanica, indicating a more complex evolutionary history of the tissues that contributed to the emergence of insect wings.
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Affiliation(s)
| | | | - Xavier Belles
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, Spain
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9
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Vauti F, Stegemann LA, Vögele V, Köster RW. All-age whole mount in situ hybridization to reveal larval and juvenile expression patterns in zebrafish. PLoS One 2020; 15:e0237167. [PMID: 32764780 PMCID: PMC7413480 DOI: 10.1371/journal.pone.0237167] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/21/2020] [Indexed: 12/12/2022] Open
Abstract
The zebrafish Danio rerio is a valuable and common model for scientists in the fields of genetics and developmental biology. Since zebrafish are also amenable to genetic manipulation, modelling of human diseases or behavioral experiments have moved into the focus of zebrafish research. Consequently, gene expression data beyond embryonic and larval stages become more important, yet there is a dramatic knowledge gap of gene expression beyond day four of development. Like in other model organisms, the visualization of spatial and temporal gene expression by whole mount in situ hybridization (ISH) becomes increasingly difficult when zebrafish embryos develop further and hence the growing tissues become dense and less permeable. Here we introduce a modified method for whole mount ISH, which overcomes these penetration and detection problem. The method is an all in one solution that enables the detection and visualization of gene expression patterns up to the late larval stage in a 3D manner without the need for tissue sectioning and offers a valuable extension for whole mount ISH by immunohistochemistry in the zebrafish field.
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Affiliation(s)
- Franz Vauti
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
- * E-mail:
| | - Luisa A. Stegemann
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Viktoria Vögele
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard W. Köster
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
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10
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Tsuneoka Y, Funato H. Modified in situ Hybridization Chain Reaction Using Short Hairpin DNAs. Front Mol Neurosci 2020; 13:75. [PMID: 32477063 PMCID: PMC7235299 DOI: 10.3389/fnmol.2020.00075] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/16/2020] [Indexed: 01/14/2023] Open
Abstract
The visualization of multiple gene expressions in well-preserved tissues is crucial for the elucidation of physiological and pathological processes. In situ hybridization chain reaction (HCR) is a method to visualize specific mRNAs in diverse organisms by applying a HCR that is an isothermal enzyme-free nucleotide polymerization method using hairpin DNAs. Although in situ HCR is a versatile method, this method is not widely used by researchers because of their higher cost than conventional in situ hybridization (ISH). Here, we redesigned hairpin DNAs so that their lengths were half the length of commonly used hairpin DNAs. We also optimized the conjugated fluorophores and linkers. Modified in situ HCR showed sufficient fluorescent signals to detect various mRNAs such as Penk, Oxtr, Vglut2, Drd1, Drd2, and Moxd1 in mouse neural tissues with a high signal-to-noise ratio. The sensitivity of modified in situ HCR in detecting the Oxtr mRNA was better than that of fluorescent ISH using tyramide signal amplification. Notably, the modified in situ HCR does not require proteinase K treatment so that it enables the preservation of morphological structures and antigenicity. The modified in situ HCR simultaneously detected the distributions of c-Fos immunoreactivity and Vglut2 mRNA, and detected multiple mRNAs with a high signal-noise ratio at subcellular resolution in mouse brains. These results suggest that the modified in situ HCR using short hairpin DNAs is cost-effective and useful for the visualization of multiple mRNAs and proteins.
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Affiliation(s)
- Yousuke Tsuneoka
- Department of Anatomy, Faculty of Medicine, Toho University, Tokyo, Japan
| | - Hiromasa Funato
- Department of Anatomy, Faculty of Medicine, Toho University, Tokyo, Japan
- International Institutes for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
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11
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Young AP, Jackson DJ, Wyeth RC. A technical review and guide to RNA fluorescence in situ hybridization. PeerJ 2020; 8:e8806. [PMID: 32219032 PMCID: PMC7085896 DOI: 10.7717/peerj.8806] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 02/25/2020] [Indexed: 12/20/2022] Open
Abstract
RNA-fluorescence in situ hybridization (FISH) is a powerful tool to visualize target messenger RNA transcripts in cultured cells, tissue sections or whole-mount preparations. As the technique has been developed over time, an ever-increasing number of divergent protocols have been published. There is now a broad selection of options available to facilitate proper tissue preparation, hybridization, and post-hybridization background removal to achieve optimal results. Here we review the technical aspects of RNA-FISH, examining the most common methods associated with different sample types including cytological preparations and whole-mounts. We discuss the application of commonly used reagents for tissue preparation, hybridization, and post-hybridization washing and provide explanations of the functional roles for each reagent. We also discuss the available probe types and necessary controls to accurately visualize gene expression. Finally, we review the most recent advances in FISH technology that facilitate both highly multiplexed experiments and signal amplification for individual targets. Taken together, this information will guide the methods development process for investigators that seek to perform FISH in organisms that lack documented or optimized protocols.
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Affiliation(s)
- Alexander P Young
- Department of Biology, St. Francis Xavier University, Antigonish, NS, Canada
| | - Daniel J Jackson
- Department of Geobiology, Georg-August Universität Göttingen, Göttingen, Germany
| | - Russell C Wyeth
- Department of Biology, St. Francis Xavier University, Antigonish, NS, Canada
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12
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Surkova S, Sokolkova A, Kozlov K, Nuzhdin SV, Samsonova M. Quantitative analysis reveals genotype- and domain- specific differences between mRNA and protein expression of segmentation genes in Drosophila. Dev Biol 2019; 448:48-58. [PMID: 30629954 DOI: 10.1016/j.ydbio.2019.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 12/12/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022]
Abstract
In many biological systems gene expression at mRNA and protein levels is not identical. Rigorous comparison of such differences on a spatio-temporal scale is still not feasible by high-throughput transcriptomic and proteomic analyses of early embryo development. Here, we characterize differences between mRNA and protein expression of Drosophila segmentation genes at the level of individual gene expression domains. We obtained quantitative imaging data on expression of gap genes gt and hb and pair-rule gene eve for Drosophila wild type embryos, Kr null mutants and Kr+/Kr- heterozygotes. To compare mRNA and protein expression we use several criteria including difference in amplitude and positions of expression domains, pattern shape and positional variability. For a number of gene expression domains we show examples where protein expression does not repeat mRNA expression even after a temporal delay. We calculated time delays between eve pattern formation at the level of mRNA and protein for wild type embryos, Kr mutants and Kr+/Kr- heterozygotes. We detect that in wild type embryos, the amplitudes of eve stripes 3 and 7 do not differ significantly at the level of mRNA, however, stripe 3 is higher than stripe 7 at the protein level. We further show that hb mRNA and protein expression in both anterior and posterior domains significantly differs at specific time points. The formation of hb PS4 stripe at the mRNA level proceeds five times faster than at the level of protein. With regard to spatial expression, we show that the offset between posterior gt mRNA and protein domains is much larger in Kr mutants than in wild type embryos and heterozygotes. Finally, we analyze differences in positional variability of eve stripe 7 expression in Kr mutants and Kr+/Kr- heterozygotes at the level of mRNA and protein. These results enable further perspectives to uncover mechanisms underlying discrepancies between mRNA and protein expression in early embryo.
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Affiliation(s)
- Svetlana Surkova
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg 195251, Russia.
| | - Alena Sokolkova
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg 195251, Russia
| | - Konstantin Kozlov
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg 195251, Russia
| | - Sergey V Nuzhdin
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg 195251, Russia; Section of Molecular and Computational Biology, University of Southern California, Los Angeles 90089, CA, USA
| | - Maria Samsonova
- Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya, 29, St. Petersburg 195251, Russia.
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13
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Kaschula R, Pinho S, Alonso CR. MicroRNA-dependent regulation of Hox gene expression sculpts fine-grain morphological patterns in a Drosophila appendage. Development 2018; 145:dev.161133. [PMID: 30143542 PMCID: PMC6215401 DOI: 10.1242/dev.161133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/06/2018] [Indexed: 11/26/2022]
Abstract
Disruptions of normal Hox gene expression can lead to severe morphological defects, revealing a link between the regulation of Hox expression and pattern formation. Here, we explore these links, focusing on the impact of microRNA regulation on the expression of the Drosophila Hox gene Ultrabithorax (Ubx) during haltere development. Through a combination of bioinformatic and transcriptomic analyses, we identify the miR-310/313 cluster (miR-310C) as a candidate regulator of Ubx. Several experiments confirm this. First, miR-310C and Ubx protein show complementary expression patterns in haltere imaginal discs; second, artificial activation of miR-310C expression in haltere discs leads to Ubx-like phenotypes. Third, expression of a fluorescent reporter bearing Ubx 3′UTR sequences is reduced when co-expressed with miR-310C. Fourth, deletion of miR-310C leads to Ubx upregulation and changes the array of mechanosensory sensilla at the base of the haltere. Fifth, an artificial increase of Ubx levels within the miR-310C expression domain phenocopies the mechanosensory defects observed in miR-310C mutants. We propose that miR-310C-mediated repression delimits Ubx fine-grain expression, contributing to the sculpting of complex morphologies in the Drosophila haltere with implications for flight control. Our work reveals a novel role of microRNA regulation in the control of Hox gene expression with impact on morphology. Summary: A novel role of microRNAs in the control of Hox gene expression with impact on the development of morphology in Drosophila, suggesting that microRNAs might play similar roles in other bilaterians.
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Affiliation(s)
- Richard Kaschula
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Sofia Pinho
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Claudio R Alonso
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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14
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Deep sequencing of the prothoracic gland transcriptome reveals new players in insect ecdysteroidogenesis. PLoS One 2017; 12:e0172951. [PMID: 28257485 PMCID: PMC5336252 DOI: 10.1371/journal.pone.0172951] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 02/13/2017] [Indexed: 12/28/2022] Open
Abstract
Ecdysteroids are steroid hormones that induce molting and determine developmental timing in arthropods. In insect larva, the prothoracic gland (PG) is a major organ for ecdysone synthesis and release. Released ecdysone is converted into the active form, 20-hydroxyecdysone (20E) in the peripheral tissues. All processes from ecdysone synthesis and release from the PG to its conversion to 20E are called ecdysteroidogenesis and are under the regulation of numerous factors expressed in the PG and peripheral tissues. Classical genetic approaches and recent transcriptomic screening in the PG identified several genes responsible for ecdysone synthesis and release, whereas the regulatory mechanism remains largely unknown. We analyzed RNA-seq data of the silkworm Bombyx mori PG and employed the fruit fly Drosophila melanogaster GAL4/UAS binary RNAi system to comprehensively screen for genes involved in ecdysone synthesis and/or release. We found that the genes encoding δ-aminolevulinic acid synthase (CG3017/alas) and putative NAD kinase (CG33156) were highly expressed in the PG of both B. mori and D. melanogaster. Neither alas nor CG33156 RNAi-induced larvae could enter into the pupal stage, and they had a lower abundance of the active form ecdysteroids in their prolonged larval stage. These results demonstrated that alas and CG33156 are indispensable for ecdysteroidogenesis.
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15
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Quijano JC, Wisotzkey RG, Tran NL, Huang Y, Stinchfield MJ, Haerry TE, Shimmi O, Newfeld SJ. lolal Is an Evolutionarily New Epigenetic Regulator of dpp Transcription during Dorsal-Ventral Axis Formation. Mol Biol Evol 2016; 33:2621-32. [PMID: 27401231 PMCID: PMC5026256 DOI: 10.1093/molbev/msw132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Secreted ligands in the Dpp/BMP family drive dorsal–ventral (D/V) axis formation in all Bilaterian species. However, maternal factors regulating Dpp/BMP transcription in this process are largely unknown. We identified the BTB domain protein longitudinals lacking-like (lolal) as a modifier of decapentaplegic (dpp) mutations. We show that Lolal is evolutionarily related to the Trithorax group of chromatin regulators and that lolal interacts genetically with the epigenetic factor Trithorax-like during Dpp D/V signaling. Maternally driven LolalHA is found in oocytes and translocates to zygotic nuclei prior to the point at which dpp transcription begins. lolal maternal and zygotic mutant embryos display significant reductions in dpp, pMad, and zerknullt expression, but they are never absent. The data suggest that lolal is required to maintain dpp transcription during D/V patterning. Phylogenetic data revealed that lolal is an evolutionarily new gene present only in insects and crustaceans. We conclude that Lolal is the first maternal protein identified with a role in dpp D/V transcriptional maintenance, that Lolal and the epigenetic protein Trithorax-like are essential for Dpp D/V signaling and that the architecture of the Dpp D/V pathway evolved in the arthropod lineage after the separation from vertebrates via the incorporation of new genes such as lolal.
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Affiliation(s)
| | | | | | - Yunxian Huang
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | | | - Theodor E Haerry
- Center for Molecular Biology and Biotechnology, Florida Atlantic University
| | - Osamu Shimmi
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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16
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Weavers H, Evans IR, Martin P, Wood W. Corpse Engulfment Generates a Molecular Memory that Primes the Macrophage Inflammatory Response. Cell 2016; 165:1658-1671. [PMID: 27212238 PMCID: PMC4912690 DOI: 10.1016/j.cell.2016.04.049] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 02/05/2016] [Accepted: 04/13/2016] [Indexed: 01/15/2023]
Abstract
Macrophages are multifunctional cells that perform diverse roles in health and disease. Emerging evidence has suggested that these innate immune cells might also be capable of developing immunological memory, a trait previously associated with the adaptive system alone. While recent studies have focused on the dramatic macrophage reprogramming that follows infection and protects against secondary microbial attack, can macrophages also develop memory in response to other cues? Here, we show that apoptotic corpse engulfment by Drosophila macrophages is an essential primer for their inflammatory response to tissue damage and infection in vivo. Priming is triggered via calcium-induced JNK signaling, which leads to upregulation of the damage receptor Draper, thus providing a molecular memory that allows the cell to rapidly respond to subsequent injury or infection. This remarkable plasticity and capacity for memory places macrophages as key therapeutic targets for treatment of inflammatory disorders. Phagocytosis of apoptotic cells primes macrophages for future inflammatory response Naive macrophages are insensitive to tissue damage and bacterial infection Corpse uptake triggers macrophage calcium bursts that potentiate priming Calcium-induced JNK primes macrophages by upregulating the damage receptor Draper
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Affiliation(s)
- Helen Weavers
- Department of Biochemistry, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK; Department of Cellular and Molecular Medicine, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Iwan R Evans
- Department of Infection, Immunity and Cardiovascular Disease and the Bateson Centre, University of Sheffield, Sheffield S10 2TN, UK
| | - Paul Martin
- Department of Biochemistry, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK; Department of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK; School of Medicine, Cardiff University, Cardiff CF14 4XN, UK; Lee Kong Chiang School of Medicine, Nanyang Technologicial University, Singapore 636921, Singapore.
| | - Will Wood
- Department of Cellular and Molecular Medicine, Biomedical Sciences, University of Bristol, Bristol BS8 1TD, UK.
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17
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Xiang J, Forrest IS, Pick L. Dermestes maculatus: an intermediate-germ beetle model system for evo-devo. EvoDevo 2015; 6:32. [PMID: 26478804 PMCID: PMC4609124 DOI: 10.1186/s13227-015-0028-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding how genes change during evolution to direct the development of diverse body plans is a major goal of the evo-devo field. Achieving this will require the establishment of new model systems that represent key points in phylogeny. These new model systems must be amenable to laboratory culture, and molecular and functional approaches should be feasible. To date, studies of insects have been best represented by the model system Drosophila melanogaster. Given the enormous diversity represented by insect taxa, comparative studies within this clade will provide a wealth of information about the evolutionary potential and trajectories of alternative developmental strategies. RESULTS Here we established the beetle Dermestes maculatus, a member of the speciose clade Coleoptera, as a new insect model system. We have maintained a continuously breeding culture in the lab and documented Dermestes maculatus embryogenesis using nuclear and phalloidin staining. Anterior segments are specified during the blastoderm stage before gastrulation, and posterior segments are added sequentially during germ band elongation. We isolated and studied the expression and function of the pair-rule segmentation gene paired in Dermestes maculatus. In this species, paired is expressed in stripes during both blastoderm and germ band stages: four primary stripes arise prior to gastrulation, confirming an intermediate-germ mode of development for this species. As in other insects, these primary stripes then split into secondary stripes. To study gene function, we established both embryonic and parental RNAi. Knockdown of Dmac-paired with either method resulted in pair-rule-like segmentation defects, including loss of Engrailed expression in alternate stripes. CONCLUSIONS These studies establish basic approaches necessary to use Dermestes maculatus as a model system. Methods are now available for use of this intermediate-germ insect for future studies of the evolution of regulatory networks controlling insect segmentation, as well as of other processes in development and homeostasis. Consistent with the role of paired in long-germ Drosophila and shorter-germ Tribolium, paired functions as a pair-rule segmentation gene in Dermestes maculatus. Thus, paired retains pair-rule function in insects with different modes of segment addition.
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Affiliation(s)
- Jie Xiang
- />Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742 USA
- />Program in Molecular and Cell Biology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742 USA
| | - Iain S. Forrest
- />Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742 USA
| | - Leslie Pick
- />Department of Entomology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742 USA
- />Program in Molecular and Cell Biology, University of Maryland, 4112 Plant Sciences Building, College Park, MD 20742 USA
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18
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Following the intracellular localization of the iab-8ncRNA of the bithorax complex using the MS2-MCP-GFP system. Mech Dev 2015; 138 Pt 2:133-140. [PMID: 26277563 DOI: 10.1016/j.mod.2015.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
Homeotic genes are aligned on the chromosome in the order of the segments that they specify along the antero-posterior axis of the fly. In general the genes affecting the more posterior segments repress the more anterior genes, a phenomenon known as "posterior dominance". There is however a noticeable exception to this rule in the central nervous system of Drosophila melanogaster where the posterior Abd-B gene does not repress the immediately more anterior abd-A gene. Instead, abd-A repression is accomplished by a 92 kb-long ncRNA (the iab-8ncRNA) that is transcribed from the large inter-genic region between abd-A and Abd-B. This iab-8ncRNA encodes a microRNA to repress abd-A and also a second redundant repression mechanism acting in cis and thought to be transcriptional interference with the abd-A promoter. Using in situ hybridization, a previous work suggested that the iab8ncRNA transcript forms discrete foci restricted to the nuclear periphery and that this localization may be important for its function. In order to better characterize the intra-cellular localization of the iab-8ncRNA we used the MS2-MCP system, which allows fluorescent labeling of RNA in cells and relies on the interaction between GFP-tagged MS2 coat protein (MCP-GFP) and MS2 RNA stem loops. Our results indicate that the large foci seen in previous studies correspond to the site of iab8ncRNA transcription and that the foci seen may simply be an indication of the level of transcription at the locus. We find no evidence to suggest that this localization is important for its function on abd-A repression. We discuss the idea that the iab-8ncRNA may be a relic of a more general ancient mechanism of posterior dominance during the emergence of the hox clusters that was mediated by transcriptional interference.
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19
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Caballero J, Gilbert I, Fournier E, Gagné D, Scantland S, Macaulay A, Robert C. Exploring the function of long non-coding RNA in the development of bovine early embryos. Reprod Fertil Dev 2015; 27:40-52. [PMID: 25472043 DOI: 10.1071/rd14338] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Now recognised as part of the cellular transcriptome, the function of long non-coding (lnc) RNA remains unclear. Previously, we found that some lncRNA molecules in bovine embryos are highly responsive to culture conditions. In view of a recent demonstration that lncRNA may play a role in regulating important functions, such as maintenance of pluripotency, modification of epigenetic marks and activation of transcription, we sought evidence of its involvement in embryogenesis. Among the numerous catalogued lncRNA molecules found in oocytes and early embryos of cattle, three candidates chosen for further characterisation were found unexpectedly in the cytoplasmic compartment rather than in the nucleus. Transcriptomic survey of subcellular fractions found these candidates also associated with polyribosomes and one of them spanning transzonal projections between cumulus cells and the oocyte. Knocking down this transcript in matured oocytes increased developmental rates, leading to larger blastocysts. Transcriptome and methylome analyses of these blastocysts showed concordant data for a subset of four genes, including at least one known to be important for blastocyst survival. Functional characterisation of the roles played by lncRNA in supporting early development remains elusive. Our results suggest that some lncRNAs play a role in translation control of target mRNA. This would be important for managing the maternal reserves within which is embedded the embryonic program, especially before embryonic genome activation.
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Affiliation(s)
- Julieta Caballero
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Isabelle Gilbert
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Eric Fournier
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Dominic Gagné
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Sara Scantland
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Angus Macaulay
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
| | - Claude Robert
- Département des sciences animales, Centre de recherche en biologie de la reproduction, Institut sur la nutrition et les aliments fonctionnels, Université Laval, 2440 boulevard Hochelaga QC, G1V 0A6, Canada
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20
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Matsuura Y, Kikuchi Y, Miura T, Fukatsu T. Ultrabithorax is essential for bacteriocyte development. Proc Natl Acad Sci U S A 2015; 112:9376-81. [PMID: 26170303 PMCID: PMC4522796 DOI: 10.1073/pnas.1503371112] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Symbiosis often entails the emergence of novel adaptive traits in organisms. Microbial symbionts are indispensable for diverse insects via provisioning of essential nutrients, wherein novel host cells and organs for harboring the microbes, called bacteriocytes and bacteriomes, have evolved repeatedly. Molecular and developmental mechanisms underpinning the emergence of novel symbiotic cells and organs comprise an unsolved question in evolutionary developmental biology. Here, we report that a conserved homeotic gene, Ultrabithorax, plays a pivotal role in the bacteriocyte differentiation in a hemipteran insect Nysius plebeius. During embryonic development, six pairs of aggregated presumptive bacteriocytes appear on both sides of six abdominal segments, incorporate the symbiotic bacteria at the stage of germband retraction, and fuse into a pair of lateral bacteriomes at the stage of germband flip, where bacteriocyte-associated Ultrabithorax expression coincides with the symbiont infection process. Suppression of Ultrabithorax expression by maternal RNA interference results in disappearance of the bacteriocytes and the symbiont localization therein, suggesting that Ultrabithorax is involved in differentiation of the host cells for symbiosis. Suppression of other homeotic genes abdominal-A and Antennapedia disturbs integrity and positioning of the bacteriomes, affecting the configuration of the host organs for symbiosis. Our findings unveil the molecular and developmental mechanisms underlying the bacteriocyte differentiation, which may have evolved either via cooption of the transcription factors for inducing the novel symbiotic cells, or via revival of the developmental pathway for the bacteriocytes that had existed in the ancestral hemipterans.
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Affiliation(s)
- Yu Matsuura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan; Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Yoshitomo Kikuchi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Hokkaido Center, Sapporo 062-8517, Japan
| | - Toru Miura
- Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Takema Fukatsu
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8566, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan;
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21
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Nguyen-Chi M, Laplace-Builhe B, Travnickova J, Luz-Crawford P, Tejedor G, Phan QT, Duroux-Richard I, Levraud JP, Kissa K, Lutfalla G, Jorgensen C, Djouad F. Identification of polarized macrophage subsets in zebrafish. eLife 2015; 4:e07288. [PMID: 26154973 PMCID: PMC4521581 DOI: 10.7554/elife.07288] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 07/07/2015] [Indexed: 12/18/2022] Open
Abstract
While the mammalian macrophage phenotypes have been intensively studied in vitro, the dynamic of their phenotypic polarization has never been investigated in live vertebrates. We used the zebrafish as a live model to identify and trail macrophage subtypes. We generated a transgenic line whose macrophages expressing tumour necrosis factor alpha (tnfa), a key feature of classically activated (M1) macrophages, express fluorescent proteins Tg(mpeg1:mCherryF/tnfa:eGFP-F). Using 4D-confocal microscopy, we showed that both aseptic wounding and Escherichia coli inoculation triggered macrophage recruitment, some of which started to express tnfa. RT-qPCR on Fluorescence Activated Cell Sorting (FACS)-sorted tnfa+ and tnfa− macrophages showed that they, respectively, expressed M1 and alternatively activated (M2) mammalian markers. Fate tracing of tnfa+ macrophages during the time-course of inflammation demonstrated that pro-inflammatory macrophages converted into M2-like phenotype during the resolution step. Our results reveal the diversity and plasticity of zebrafish macrophage subsets and underline the similarities with mammalian macrophages proposing a new system to study macrophage functional dynamic. DOI:http://dx.doi.org/10.7554/eLife.07288.001 Inflammation plays an important role in helping the body to heal wounds and fight off certain diseases. Immune cells called macrophages—which are perhaps best known for their ability to engulf and digest microbes and cell debris—help to control inflammation. In mammals, different types of macrophage exist; the most functionally extreme of which are the M1 macrophages that stimulate inflammation and M2 macrophages that reduce the inflammatory response. Macrophages acquire different abilities through a process called polarization, which is controlled by signals produced by a macrophage's environment. Polarization has been well investigated in human and mouse cells grown in the laboratory, but less is understood about how this process occurs in live animals. Nguyen Chi, Laplace-Builhe et al. investigated whether zebrafish larvae (which are naturally transparent) could form an experimental model in which to investigate macrophage polarization in living animals. Zebrafish were first genetically engineered to produce two fluorescent proteins: one that marks macrophages and one that marks M1 macrophages. These fluorescent proteins allow the movement and polarization of macrophages to be tracked in real time in living larvae using a technique called confocal microscopy. Nguyen Chi, Laplace-Builhe et al. also isolated macrophage cells from these zebrafish at different times during the inflammatory process to identify which macrophage subtypes form and when. The results show that unpolarized macrophages move to the sites of inflammation (caused by wounds or bacterial infection), where they become polarized into M1 cells. Over time, these M1 macrophages progressively convert into an M2-like macrophage subtype, presumably to help clear up the inflammation. Furthermore, Nguyen Chi, Laplace-Builhe et al. show that the M1 and M2 macrophage subtypes in zebrafish are similar to those found in mammals. Therefore, genetically engineered zebrafish larvae are likely to prove useful for studying macrophage activity and polarization in living animals. DOI:http://dx.doi.org/10.7554/eLife.07288.002
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Affiliation(s)
- Mai Nguyen-Chi
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | - Béryl Laplace-Builhe
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | | | - Patricia Luz-Crawford
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | - Gautier Tejedor
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | - Quang Tien Phan
- Dynamique des Interactions Membranaires Normales et Pathologiques, Centre national de la recherche scientifique, Montpellier, France
| | - Isabelle Duroux-Richard
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | | | | | | | - Christian Jorgensen
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
| | - Farida Djouad
- Institut de Médecine Régénérative et Biothérapies, Institut national de la santé et de la recherche médicale, Montpellier, France
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22
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A positional Toll receptor code directs convergent extension in Drosophila. Nature 2014; 515:523-7. [PMID: 25363762 DOI: 10.1038/nature13953] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 10/09/2014] [Indexed: 12/21/2022]
Abstract
Elongation of the head-to-tail body axis by convergent extension is a conserved developmental process throughout metazoans. In Drosophila, patterns of transcription factor expression provide spatial cues that induce systematically oriented cell movements and promote tissue elongation. However, the mechanisms by which patterned transcriptional inputs control cell polarity and behaviour have long been elusive. We demonstrate that three Toll family receptors, Toll-2, Toll-6 and Toll-8, are expressed in overlapping transverse stripes along the anterior-posterior axis and act in combination to direct planar polarity and polarized cell rearrangements during convergent extension. Simultaneous disruption of all three receptors strongly reduces actomyosin-driven junctional remodelling and axis elongation, and an ectopic stripe of Toll receptor expression is sufficient to induce planar polarized actomyosin contractility. These results demonstrate that tissue-level patterns of Toll receptor expression provide spatial signals that link positional information from the anterior-posterior patterning system to the essential cell behaviours that drive convergent extension.
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23
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Baker NE, Li K, Quiquand M, Ruggiero R, Wang LH. Eye development. Methods 2014; 68:252-9. [PMID: 24784530 DOI: 10.1016/j.ymeth.2014.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 04/07/2014] [Accepted: 04/09/2014] [Indexed: 12/21/2022] Open
Abstract
The eye has been one of the most intensively studied organs in Drosophila. The wealth of knowledge about its development, as well as the reagents that have been developed, and the fact that the eye is dispensable for survival, also make the eye suitable for genetic interaction studies and genetic screens. This article provides a brief overview of the methods developed to image and probe eye development at multiple developmental stages, including live imaging, immunostaining of fixed tissues, in situ hybridizations, and scanning electron microscopy and color photography of adult eyes. Also summarized are genetic approaches that can be performed in the eye, including mosaic analysis and conditional mutation, gene misexpression and knockdown, and forward genetic and modifier screens.
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Affiliation(s)
- Nicholas E Baker
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States; Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States; Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States.
| | - Ke Li
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
| | - Manon Quiquand
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
| | - Robert Ruggiero
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
| | - Lan-Hsin Wang
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
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24
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Weavers H, Skaer H. Tip cells act as dynamic cellular anchors in the morphogenesis of looped renal tubules in Drosophila. Dev Cell 2014; 27:331-44. [PMID: 24229645 PMCID: PMC3898071 DOI: 10.1016/j.devcel.2013.09.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 09/06/2013] [Accepted: 09/22/2013] [Indexed: 01/13/2023]
Abstract
Tissue morphogenesis involves both the sculpting of tissue shape and the positioning of tissues relative to one another in the body. Using the renal tubules of Drosophila, we show that a specific distal tubule cell regulates both tissue architecture and position in the body cavity. Focusing on the anterior tubules, we demonstrate that tip cells make transient contacts with alary muscles at abdominal segment boundaries, moving progressively forward as convergent extension movements lengthen the tubule. Tip cell anchorage antagonizes forward-directed, TGF-β-guided tubule elongation, thereby ensuring the looped morphology characteristic of renal tubules from worms to humans. Distinctive tip cell exploratory behavior, adhesion, and basement membrane clearing underlie target recognition and dynamic interactions. Defects in these features obliterate tip cell anchorage, producing misshapen and misplaced tubules with impaired physiological function. Tip cells stabilize elongating renal tubules by binding to specific muscle targets Tip cell anchorage antagonizes migration, producing excretory tubule looping Tip cell exploration and adhesion dynamics underpin regulated tubule morphogenesis Lack of continued anchorage results in deformed tubules with impaired function
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Affiliation(s)
- Helen Weavers
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
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25
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GATA simple sequence repeats function as enhancer blocker boundaries. Nat Commun 2013; 4:1844. [PMID: 23673629 DOI: 10.1038/ncomms2872] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 04/11/2013] [Indexed: 11/09/2022] Open
Abstract
Simple sequence repeats (SSRs) account for ~3% of the human genome, but their functional significance still remains unclear. One of the prominent SSRs the GATA tetranucleotide repeat has preferentially accumulated in complex organisms. GATA repeats are particularly enriched on the human Y chromosome, and their non-random distribution and exclusive association with genes expressed during early development indicate their role in coordinated gene regulation. Here we show that GATA repeats have enhancer blocker activity in Drosophila and human cells. This enhancer blocker activity is seen in transgenic as well as native context of the enhancers at various developmental stages. These findings ascribe functional significance to SSRs and offer an explanation as to why SSRs, especially GATA, may have accumulated in complex organisms.
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26
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Optimized RNA ISH, RNA FISH and protein-RNA double labeling (IF/FISH) in Drosophila ovaries. Nat Protoc 2013; 8:2158-79. [PMID: 24113787 DOI: 10.1038/nprot.2013.136] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In situ hybridization (ISH) is a powerful technique for detecting nucleic acids in cells and tissues. Here we describe three ISH procedures that are optimized for Drosophila ovaries: whole-mount, digoxigenin-labeled RNA ISH; RNA fluorescent ISH (FISH); and protein immunofluorescence (IF)-RNA FISH double labeling (IF/FISH). Each procedure balances conflicting requirements for permeabilization, fixation and preservation of antigenicity to detect RNA and protein expression with high resolution and sensitivity. The ISH protocol uses alkaline phosphatase-conjugated digoxigenin antibodies followed by a color reaction, whereas FISH detection involves tyramide signal amplification (TSA). To simultaneously preserve antigens for protein detection and enable RNA probe penetration for IF/FISH, we perform IF before FISH and use xylenes and detergents to permeabilize the tissue rather than proteinase K, which can damage the antigens. ISH and FISH take 3 d to perform, whereas IF/FISH takes 5 d. Probe generation takes 1 or 2 d to perform.
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27
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Abstract
RNA transcripts without obvious coding potential are widespread in many creatures, including the fruit fly, Drosophila melanogaster. Several noncoding RNAs have been identified within the Drosophila bithorax complex. These first appear in blastoderm stage embryos, and their expression patterns indicate that they are transcribed only from active domains of the bithorax complex. It has been suggested that these noncoding RNAs have a role in establishing active domains, perhaps by setting the state of Polycomb Response Elements A comprehensive survey across the proximal half of the bithorax complex has now revealed nine distinct noncoding RNA transcripts, including four within the Ultrabithorax transcription unit. At the blastoderm stage, the noncoding transcripts collectively span ∼75% of the 135 kb surveyed. Recombination-mediated cassette exchange was used to invert the promoter of one of the noncoding RNAs, a 23-kb transcript from the bxd domain of the bithorax complex. The resulting animals fail to make the normal bxd noncoding RNA and show no transcription across the bxd Polycomb Response Element in early embryos. The mutant flies look normal; the regulation of the bxd domain appears unaffected. Thus, the bxd noncoding RNA has no apparent function.
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28
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Kadakkuzha BM, Puthanveettil SV. Genomics and proteomics in solving brain complexity. MOLECULAR BIOSYSTEMS 2013; 9:1807-21. [PMID: 23615871 DOI: 10.1039/c3mb25391k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human brain is extraordinarily complex, composed of billions of neurons and trillions of synaptic connections. Neurons are organized into circuit assemblies that are modulated by specific interneurons and non-neuronal cells, such as glia and astrocytes. Data on human genome sequences predicts that each of these cells in the human brain has the potential of expressing ∼20 000 protein coding genes and tens of thousands of noncoding RNAs. A major challenge in neuroscience is to determine (1) how individual neurons and circuitry utilize this potential during development and maturation of the nervous system, and for higher brain functions such as cognition, and (2) how this potential is altered in neurological and psychiatric disorders. In this review, we will discuss how recent advances in next generation sequencing, proteomics and bioinformatics have transformed our understanding of gene expression and the functions of neural circuitry, memory storage, and disorders of cognition.
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Affiliation(s)
- Beena M Kadakkuzha
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida 130 Scripps Way, Jupiter, FL 33458, USA
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29
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Characterization of Drosophila GDNF receptor-like and evidence for its evolutionarily conserved interaction with neural cell adhesion molecule (NCAM)/FasII. PLoS One 2012; 7:e51997. [PMID: 23284846 PMCID: PMC3527400 DOI: 10.1371/journal.pone.0051997] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 11/09/2012] [Indexed: 01/01/2023] Open
Abstract
Background Glial cell line-derived neurotrophic factor (GDNF) family ligands are secreted growth factors distantly related to the TGF-β superfamily. In mammals, they bind to the GDNF family receptor α (Gfrα) and signal through the Ret receptor tyrosine kinase. In order to gain insight into the evolution of the Ret-Gfr-Gdnf signaling system, we have cloned and characterized the first invertebrate Gfr-like cDNA (DmGfrl) from Drosophila melanogaster and generated a DmGfrl mutant allele. Results We found that DmGfrl encodes a large GPI-anchored membrane protein with four GFR-like domains. In line with the fact that insects lack GDNF ligands, DmGfrl mediated neither Drosophila Ret phosphorylation nor mammalian RET phosphorylation. In situ hybridization analysis revealed that DmGfrl is expressed in the central and peripheral nervous systems throughout Drosophila development, but, surprisingly, DmGfrl and DmRet expression patterns were largely non-overlapping. We generated a DmGfrl null allele by genomic FLP deletion and found that both DmGfrl null females and males are viable but display fertility defects. The female fertility defect manifested as dorsal appendage malformation, small size and reduced viability of eggs laid by mutant females. In male flies DmGfrl interacted genetically with the Drosophila Ncam (neural cell adhesion molecule) homolog FasII to regulate fertility. Conclusion Our results suggest that Ret and Gfrl did not function as an in cis receptor-coreceptor pair before the emergence of GDNF family ligands, and that the Ncam-Gfr interaction predated the in cis Ret-Gfr interaction in evolution. The fertility defects that we describe in DmGfrl null flies suggest that GDNF receptor-like has an evolutionarily ancient role in regulating male fertility and a previously unrecognized role in regulating oogenesis. Significance These results shed light on the evolutionary aspects of the structure, expression and function of Ret-Gfrα and Ncam-Gfrα signaling complexes.
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Abstract
Detection of RNAs by in situ hybridization (ISH) is a well-established technique that permits the study of specific RNA expression patterns in tissues; however, not all tissues are equally amenable to staining using the same procedure. Here we describe a protocol that combines whole-mount immunofluorescence (IF) and fluorescence in situ hybridization (FISH) for the simultaneous detection of specific RNA transcripts and proteins, greatly enhancing the spatial resolution of RNA expression in complex, intact fly tissues. To date, we have successfully used this protocol in adult testis, larval male gonads, adult intestine and Malpighian tubules. IF is conducted in RNase-free solutions, prior to the harsh conditions of FISH, in order to preserve protein antigenicity within dissected tissues. Separate protocols are described for mRNA and miRNA detection, which are based on robust digoxigenin (DIG) RNA and locked nucleic acid (LNA) probes, respectively. The combined IF-FISH procedure can be completed in 2 d for miRNA detection and 4 d for mRNA detection. Although optimized for Drosophila, this IF-FISH protocol should be adaptable to a wide variety of organisms, tissues, antibodies and probes, thus providing a reliable and simple means to compare RNA and protein abundance and localization.
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Elbeik T, Shults K, Patterson BK. Simultaneous ultrasensitive subpopulation staining/hybridization in situ: multiplex analyses of transcriptionally active HIV-1 intact cell reservoirs. Future Virol 2012. [DOI: 10.2217/fvl.12.72] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Tarek Elbeik
- Elbeik Associates LLC.,584 Castro Street #349, San Francisco, CA, USA
| | - Keith Shults
- IncellDx Inc. 1700 El Camino Real, Menlo Park, CA, USA
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Mouri K, Horiuchi SY, Uemura T. Cohesin controls planar cell polarity by regulating the level of the seven-pass transmembrane cadherin Flamingo. Genes Cells 2012; 17:509-24. [PMID: 22563761 DOI: 10.1111/j.1365-2443.2012.01604.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Planar cell polarity (PCP) refers to the coordination of global organ axes and individual cell polarity in vertebrate and invertebrate epithelia. Mechanisms of PCP have been best studied in the Drosophila wing, in which each epidermal cell produces a single wing hair at the distal cell edge, and this spatial specification is mediated by redistribution of the core group proteins, including the seven-pass transmembrane cadherin Flamingo/Starry night (Fmi/Stan), to selective plasma membrane domains. Through genetic screening, we found that a mutation of the SMC3 gene caused dramatic misspecification of wing hair positions. SMC3 protein is one subunit of the cohesin complex, which regulates sister chromatid cohesion and also plays a role in transcriptional control of gene expression. In the SMC3 mutant cells, Fmi appeared to be upregulated by a posttranscriptional mechanism(s), and this elevation of Fmi was at least one cause of the PCP defect. In addition to the PCP phenotype, the loss of the cohesin function affected wing morphogenesis at multiple levels: one malformation was loss of the wing margin, and this was most likely a result of downregulation of the homeodomain protein Cut. At the cellular level, apical cell size and hexagonal packing were affected in the mutant wing. Dysfunction of cohesin in humans results in Cornelia de Lange syndrome (CdLS), which is characterized by various developmental abnormalities and mental retardation. Our analysis of cohesin in epithelia may provide new insight into cellular and molecular mechanisms of CdLS.
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Affiliation(s)
- Kousuke Mouri
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
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Gummalla M, Maeda RK, Castro Alvarez JJ, Gyurkovics H, Singari S, Edwards KA, Karch F, Bender W. abd-A regulation by the iab-8 noncoding RNA. PLoS Genet 2012; 8:e1002720. [PMID: 22654672 PMCID: PMC3359974 DOI: 10.1371/journal.pgen.1002720] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 04/03/2012] [Indexed: 12/29/2022] Open
Abstract
The homeotic genes in Drosophila melanogaster are aligned on the chromosome in the order of the body segments that they affect. The genes affecting the more posterior segments repress the more anterior genes. This posterior dominance rule must be qualified in the case of abdominal-A (abd-A) repression by Abdominal-B (Abd-B). Animals lacking Abd-B show ectopic expression of abd-A in the epidermis of the eighth abdominal segment, but not in the central nervous system. Repression in these neuronal cells is accomplished by a 92 kb noncoding RNA. This “iab-8 RNA” produces a micro RNA to repress abd-A, but also has a second, redundant repression mechanism that acts only “in cis.” Transcriptional interference with the abd-A promoter is the most likely mechanism. Although long, noncoding RNAs have been found in many organisms, it has been difficult to assign to them any molecular function. The homeotic gene clusters in the fruit fly, Drosophila melanogaster, contain many such noncoding RNAs. We have characterized one such noncoding RNA, a 92 kb transcription unit from within the bithorax complex. This transcript, called the iab-8 ncRNA, is made in the cells of the central nervous system in the eighth abdominal segment, along with the homeotic transcription factor Abdominal-B. Another homeotic transcription factor, abdominal-A, is repressed in these cells. It has generally been assumed that abdominal-A repression in these cells is mediated by the Abdominal-B protein. However, here we show that it is not Abdominal-B that represses abdominal-A, but the iab-8 ncRNA. This repression is accomplished by two redundant mechanisms; the iab-8 precursor produces a micro RNA, which targets the abdominal-A mRNA, and iab-8 transcription interferes with the abdominal-A promoter, which lies just downstream of the iab-8 ncRNA poly(A) site.
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Affiliation(s)
- Maheshwar Gummalla
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland
| | - Robert K. Maeda
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland
| | | | | | - Swetha Singari
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
| | - Kevin A. Edwards
- School of Biological Sciences, Illinois State University, Normal, Illinois, United States of America
| | - François Karch
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland
- * E-mail: (FK); (WB)
| | - Welcome Bender
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (FK); (WB)
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Three Drosophila Hox complex microRNAs do not have major effects on expression of evolutionarily conserved Hox gene targets during embryogenesis. PLoS One 2012; 7:e31365. [PMID: 22393361 PMCID: PMC3290615 DOI: 10.1371/journal.pone.0031365] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 01/09/2012] [Indexed: 12/21/2022] Open
Abstract
The discovery of microRNAs has resulted in a major expansion of the number of molecules known to be involved in gene regulation. Elucidating the functions of animal microRNAs has posed a significant challenge as their target interactions with messenger RNAs do not adhere to simple rules. Of the thousands of known animal microRNAs, relatively few microRNA:messenger RNA regulatory interactions have been biologically validated in an normal organismal context. Here we present evidence that three microRNAs from the Hox complex in Drosophila (miR-10-5p, miR-10-3p, miR-iab-4-5p) do not have significant effects during embryogenesis on the expression of Hox genes that contain high confidence microRNAs target sites in the 3′ untranslated regions of their messenger RNAs. This is significant, in that it suggests that many predicted microRNA-target interactions may not be biologically relevant, or that the outcomes of these interactions may be so subtle that mutants may only show phenotypes in specific contexts, such as in environmental stress conditions, or in combinations with other microRNA mutations.
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Kawamori H, Tai M, Sato M, Yasugi T, Tabata T. Fat/Hippo pathway regulates the progress of neural differentiation signaling in the Drosophila optic lobe. Dev Growth Differ 2011; 53:653-67. [PMID: 21671914 DOI: 10.1111/j.1440-169x.2011.01279.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A large number of neural and glial cell species differentiate from neuronal precursor cells during nervous system development. Two types of Drosophila optic lobe neurons, lamina and medulla neurons, are derived from the neuroepithelial (NE) cells of the outer optic anlagen. During larval development, epidermal growth factor receptor (EGFR)/Ras signaling sweeps the NE field from the medial edge and drives medulla neuroblast (NB) formation. This signal drives the transient expression of a proneural gene, lethal of scute, and we refer to its signal array as the "proneural wave," as it is the marker of the EGFR/Ras signaling front. In this study, we show that the atypical cadherin Fat and the downstream Hippo pathways regulate the transduction of EGFR/Ras signaling along the NE field and, thus, ensure the progress of NB differentiation. Fat/Hippo pathway mutation also disrupts the pattern formation of the medulla structure, which is associated with the regulation of neurogenesis. A candidate for the Fat ligand, Dachsous is expressed in the posterior optic lobe, and its mutation was observed to cause a similar phenotype as fat mutation, although in a regionally restricted manner. We also show that Dachsous functions as the ligand in this pathway and genetically interacts with Fat in the optic lobe. These findings provide new insights into the function of the Fat/Hippo pathway, which regulates the ordered progression of neurogenesis in the complex nervous system.
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Affiliation(s)
- Haruhiko Kawamori
- Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku Tokyo 113-0032, Japan
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Sultana H, Verma S, Mishra RK. A BEAF dependent chromatin domain boundary separates myoglianin and eyeless genes of Drosophila melanogaster. Nucleic Acids Res 2011; 39:3543-57. [PMID: 21247873 PMCID: PMC3089456 DOI: 10.1093/nar/gkq1297] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Precise transcriptional control is dependent on specific interactions of a number of regulatory elements such as promoters, enhancers and silencers. Several studies indicate that the genome in higher eukaryotes is divided into chromatin domains with functional autonomy. Chromatin domain boundaries are a class of regulatory elements that restrict enhancers to interact with appropriate promoters and prevent misregulation of genes. While several boundary elements have been identified, a rational approach to search for such elements is lacking. With a view to identifying new chromatin domain boundary elements we analyzed genomic regions between closely spaced but differentially expressed genes of Drosophila melanogaster. We have identified a new boundary element between myoglianin and eyeless, ME boundary, that separates these two differentially expressed genes. ME boundary maps to a DNaseI hypersensitive site and acts as an enhancer blocker both in embryonic and adult stages in transgenic context. We also report that BEAF and GAF are the two major proteins responsible for the ME boundary function. Our studies demonstrate a rational approach to search for potential boundaries in genomic regions that are well annotated.
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Affiliation(s)
- Hina Sultana
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500007, India
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37
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Abstract
Tissue-specific gene expression is a major determinant in the elaboration of cells with distinctive phenotypes and functions, which is crucial for the development and homeostasis of multicellular organisms. Fluorescent in situ hybridization (FISH) is a powerful method for assessing the expression and localization properties of RNA at subcellular resolution in whole mount organism and tissue specimens. This chapter describes a high-resolution FISH protocol for the detection of RNA expression and localization dynamics in embryos and tissues of the fruit fly, Drosophila melanogaster. The approach utilizes tyramide signal amplification (TSA) for enhanced sensitivity and resolution in the detection of coding and noncoding RNAs, for the codetection of different RNA species or of RNA and a protein marker of interest. Furthermore, the protocol outlines details for conducting FISH in microtiter plates, which greatly enhances the throughput, practicality, and economy of the procedure.
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Regulation and functions of the lms homeobox gene during development of embryonic lateral transverse muscles and direct flight muscles in Drosophila. PLoS One 2010; 5:e14323. [PMID: 21179520 PMCID: PMC3002276 DOI: 10.1371/journal.pone.0014323] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 11/16/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Patterning and differentiation of developing musculatures require elaborate networks of transcriptional regulation. In Drosophila, significant progress has been made into identifying the regulators of muscle development and defining their interactive networks. One major family of transcription factors involved in these processes consists of homeodomain proteins. In flies, several members of this family serve as muscle identity genes to specify the fates of individual muscles, or groups thereof, during embryonic and/or adult muscle development. Herein, we report on the expression and function of a new Drosophila homeobox gene during both embryonic and adult muscle development. METHODOLOGY/PRINCIPAL FINDINGS The newly described homeobox gene, termed lateral muscles scarcer (lms), which has yet uncharacterized orthologs in other invertebrates and primitive chordates but not in vertebrates, is expressed exclusively in subsets of developing muscle tissues. In embryos, lms is expressed specifically in the four lateral transverse (LT) muscles and their founder cells in each hemisegment, whereas in larval wing imaginal discs, it is expressed in myoblasts that develop into direct flight muscles (DFMs), which are important for proper wing positioning. We have analyzed the regulatory inputs of various other muscle identity genes with overlapping or complementary expression patterns towards the cell type specific regulation of lms expression. Further we demonstrate that lms null mutants exhibit reduced numbers of embryonic LT muscles, and null mutant adults feature held-out-wing phenotypes. We provide a detailed description of the pattern and morphology of the direct flight muscles in the wild type and lms mutant flies by using the recently-developed ultramicroscopy and show that, in the mutants, all DFMs are present and present normal morphologies. CONCLUSIONS/SIGNIFICANCE We have identified the homeobox gene lms as a new muscle identity gene and show that it interacts with various previously-characterized muscle identity genes to regulate normal formation of embryonic lateral transverse muscles. In addition, the direct flight muscles in the adults require lms for reliably exerting their functions in controlling wing postures.
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Bunt S, Denholm B, Skaer H. Characterisation of the Drosophila procollagen lysyl hydroxylase, dPlod. Gene Expr Patterns 2010; 11:72-8. [PMID: 20888931 PMCID: PMC3044864 DOI: 10.1016/j.gep.2010.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 09/22/2010] [Accepted: 09/23/2010] [Indexed: 12/04/2022]
Abstract
The lysyl hydroxylase (LH) family of enzymes has important roles in the biosynthesis of collagen. In this paper we present the first description of Drosophila LH3 (dPlod), the only lysyl hydroxylase encoded in the fly genome. We have characterised in detail the developmental expression patterns of dPlod RNA and protein during embryogenesis. Consistent with its predicted function as a collagen-modifying enzyme, we find that dPlod is highly expressed in type-IV collagen-producing cells, particularly the haemocytes and fat body. Examination of dPlod subcellular localisation reveals that it is an endoplasmic reticulum resident protein, that partially overlaps with intracellular type-IV collagen. Furthermore, we show that dPlod is required for type-IV collagen secretion from haemocytes and fat body, and thus establish that LH3 enzyme function is conserved across widely separated animal phyla. Our findings, and the new tools we describe, establish the fly as an attractive model in which to study this important collagen biosynthesis enzyme.
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Affiliation(s)
- Stephanie Bunt
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK
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Hemocyte-secreted type IV collagen enhances BMP signaling to guide renal tubule morphogenesis in Drosophila. Dev Cell 2010; 19:296-306. [PMID: 20708591 PMCID: PMC2941037 DOI: 10.1016/j.devcel.2010.07.019] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 07/09/2010] [Accepted: 07/28/2010] [Indexed: 12/17/2022]
Abstract
Details of the mechanisms that determine the shape and positioning of organs in the body cavity remain largely obscure. We show that stereotypic positioning of outgrowing Drosophila renal tubules depends on signaling in a subset of tubule cells and results from enhanced sensitivity to guidance signals by targeted matrix deposition. VEGF/PDGF ligands from the tubules attract hemocytes, which secrete components of the basement membrane to ensheath them. Collagen IV sensitizes tubule cells to localized BMP guidance cues. Signaling results in pathway activation in a subset of tubule cells that lead outgrowth through the body cavity. Failure of hemocyte migration, loss of collagen IV, or abrogation of BMP signaling results in tubule misrouting and defective organ shape and positioning. Such regulated interplay between cell-cell and cell-matrix interactions is likely to have wide relevance in organogenesis and congenital disease.
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Yasugi T, Sugie A, Umetsu D, Tabata T. Coordinated sequential action of EGFR and Notch signaling pathways regulates proneural wave progression in the Drosophila optic lobe. Development 2010; 137:3193-203. [PMID: 20724446 DOI: 10.1242/dev.048058] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During neurogenesis in the medulla of the Drosophila optic lobe, neuroepithelial cells are programmed to differentiate into neuroblasts at the medial edge of the developing optic lobe. The wave of differentiation progresses synchronously in a row of cells from medial to the lateral regions of the optic lobe, sweeping across the entire neuroepithelial sheet; it is preceded by the transient expression of the proneural gene lethal of scute [l(1)sc] and is thus called the proneural wave. We found that the epidermal growth factor receptor (EGFR) signaling pathway promotes proneural wave progression. EGFR signaling is activated in neuroepithelial cells and induces l(1)sc expression. EGFR activation is regulated by transient expression of Rhomboid (Rho), which is required for the maturation of the EGF ligand Spitz. Rho expression is also regulated by the EGFR signal. The transient and spatially restricted expression of Rho generates sequential activation of EGFR signaling and assures the directional progression of the differentiation wave. This study also provides new insights into the role of Notch signaling. Expression of the Notch ligand Delta is induced by EGFR, and Notch signaling prolongs the proneural state. Notch signaling activity is downregulated by its own feedback mechanism that permits cells at proneural states to subsequently develop into neuroblasts. Thus, coordinated sequential action of the EGFR and Notch signaling pathways causes the proneural wave to progress and induce neuroblast formation in a precisely ordered manner.
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Affiliation(s)
- Tetsuo Yasugi
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Hsia CC, Paré AC, Hannon M, Ronshaugen M, McGinnis W. Silencing of an abdominal Hox gene during early development is correlated with limb development in a crustacean trunk. Evol Dev 2010; 12:131-43. [PMID: 20433454 DOI: 10.1111/j.1525-142x.2010.00399.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We tested whether Artemia abd-A could repress limbs in Drosophila embryos, and found that although abd-A transcripts were produced, ABD-A protein was not. Similarly, developing Artemia epidermal cells showed expression of abd-A transcripts without accumulation of ABD-A protein. This finding in Artemia reveals a new variation in Hox gene function that is associated with morphological evolution. In this case, a HOX protein expression pattern is completely absent during early development, although the HOX protein is expressed at later stages in the central nervous system in a "homeotic-like" pattern. The combination of an absence of ABD-A protein expression in the Artemia limb primordia and the weak repressive function of Artemia UBX protein on the limb-promoting gene Dll are likely to be two reasons why homonomous limbs develop throughout the entire Artemia trunk.
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Affiliation(s)
- Cheryl C Hsia
- Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
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Figeac N, Jagla T, Aradhya R, Da Ponte JP, Jagla K. Drosophila adult muscle precursors form a network of interconnected cells and are specified by the rhomboid-triggered EGF pathway. Development 2010; 137:1965-73. [PMID: 20463031 DOI: 10.1242/dev.049080] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Drosophila, a population of muscle-committed stem-like cells called adult muscle precursors (AMPs) keeps an undifferentiated and quiescent state during embryonic life. The embryonic AMPs are at the origin of all adult fly muscles and, as we demonstrate here, they express repressors of myogenic differentiation and targets of the Notch pathway known to be involved in muscle cell stemness. By targeting GFP to the AMP cell membranes, we show that AMPs are tightly associated with the peripheral nervous system and with a subset of differentiated muscles. They send long cellular processes running along the peripheral nerves and, by the end of embryogenesis, form a network of interconnected cells. Based on evidence from laser ablation experiments, the main role of these cellular extensions is to maintain correct spatial positioning of AMPs. To gain insights into mechanisms that lead to AMP cell specification, we performed a gain-of-function screen with a special focus on lateral AMPs expressing the homeobox gene ladybird. Our data show that the rhomboid-triggered EGF signalling pathway controls both the specification and the subsequent maintenance of AMP cells. This finding is supported by the identification of EGF-secreting cells in the lateral domain and the EGF-dependent regulatory modules that drive expression of the ladybird gene in lateral AMPs. Taken together, our results reveal an unsuspected capacity of embryonic AMPs to form a cell network, and shed light on the mechanisms governing their specification and maintenance.
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Affiliation(s)
- Nicolas Figeac
- GReD, INSERM U931, CNRS UMR6247, Clermont University, Faculté de Médecine, 28 Place Henri Dunant, Clermont-Ferrand, 63000, France
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Funakoshi Y, Negishi Y, Gergen JP, Seino J, Ishii K, Lennarz WJ, Matsuo I, Ito Y, Taniguchi N, Suzuki T. Evidence for an essential deglycosylation-independent activity of PNGase in Drosophila melanogaster. PLoS One 2010; 5:e10545. [PMID: 20479940 PMCID: PMC2866665 DOI: 10.1371/journal.pone.0010545] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 04/12/2010] [Indexed: 12/03/2022] Open
Abstract
Background Peptide:N-glycanase (PNGase) is an enzyme which releases N-linked glycans from glycopeptides/glycoproteins. This enzyme plays a role in the ER-associated degradation (ERAD) pathway in yeast and mice, but the biological importance of this activity remains unknown. Principal Findings In this study, we characterized the ortholog of cytoplasmic PNGases, PNGase-like (Pngl), in Drosophila melanogaster. Pngl was found to have a molecular weight of ∼74K and was mainly localized in the cytosol. Pngl lacks a CXXC motif that is critical for enzymatic activity in other species and accordingly did not appear to possess PNGase activity, though it still retains carbohydrate-binding activity. We generated microdeletions in the Pngl locus in order to investigate the functional importance of this protein in vivo. Elimination of Pngl led to a serious developmental delay or arrest during the larval and pupal stages, and surviving mutant adult males and females were frequently sterile. Most importantly, these phenotypes were rescued by ubiquitous expression of Pngl, clearly indicating that those phenotypic consequences were indeed due to the lack of functional Pngl. Interestingly, a putative “catalytic-inactive” mutant could not rescue the growth-delay phenotype, indicating that a biochemical activity of this protein is important for its biological function. Conclusion Pngl was shown to be inevitable for the proper developmental transition and the biochemical properties other than deglycosylation activity is important for its biological function.
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Affiliation(s)
- Yoko Funakoshi
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Advanced Science Institute, Wako, Saitama, Japan
- * E-mail: (YF); (TS)
| | - Yuki Negishi
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Advanced Science Institute, Wako, Saitama, Japan
| | - J. Peter Gergen
- Department of Biochemistry and Cell Biology and the Center for Developmental Genetics, Stony Brook University, Stony Brook, New York, United States of America
| | - Junichi Seino
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Advanced Science Institute, Wako, Saitama, Japan
| | - Kumiko Ishii
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Advanced Science Institute, Wako, Saitama, Japan
| | - William J. Lennarz
- Department of Biochemistry and Cell Biology and Institute for Cell and Developmental Biology, Stony Brook University, Stony Brook, New York, United States of America
| | - Ichiro Matsuo
- Department of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma, Japan
| | - Yukishige Ito
- Synthetic Cellular Chemistry Laboratory, RIKEN Advanced Science Institute, Wako, Saitama, Japan
- Glycotrilogy Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan
| | - Naoyuki Taniguchi
- Department of Disease Glycomics, The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan
- Disease Glycomics Team, RIKEN Advanced Science Institute, Wako, Saitama, Japan
| | - Tadashi Suzuki
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Advanced Science Institute, Wako, Saitama, Japan
- Core Research for Evolutionary Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan
- * E-mail: (YF); (TS)
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Paré A, Lemons D, Kosman D, Beaver W, Freund Y, McGinnis W. Visualization of individual Scr mRNAs during Drosophila embryogenesis yields evidence for transcriptional bursting. Curr Biol 2010; 19:2037-42. [PMID: 19931455 DOI: 10.1016/j.cub.2009.10.028] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Revised: 09/11/2009] [Accepted: 10/08/2009] [Indexed: 11/18/2022]
Abstract
The detection and counting of transcripts within single cells via fluorescent in situ hybridization (FISH) has allowed researchers to ask quantitative questions about gene expression at the level of individual cells. This method is often preferable to quantitative RT-PCR, because it does not necessitate destruction of the cells being probed and maintains spatial information that may be of interest. Until now, studies using FISH at single-molecule resolution have only been rigorously carried out in isolated cells (e.g., yeast cells or mammalian cell culture). Here, we describe the detection and counting of transcripts within single cells of fixed, whole-mount Drosophila embryos via a combination of FISH, immunohistochemistry, and image segmentation. Our method takes advantage of inexpensive, long RNA probes detected with antibodies, and we present novel evidence to show that we can robustly detect single mRNA molecules. We use this method to characterize transcription at the endogenous locus of the Hox gene Sex combs reduced (Scr), by comparing a stably expressing group of cells to a group that only transiently expresses the gene. Our data provide evidence for transcriptional bursting, as well for divergent "accumulation" and "maintenance" phases of gene activity at the Scr locus.
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Affiliation(s)
- Adam Paré
- Section of Cell and Developmental Biology, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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YOKOYAMA KK, MURATA T, PAN J, NAKADE K, KISHIKAWA S, UGAI H, KIMURA M, KUJIME Y, HIROSE M, MASUZAKI S, YAMASAKI T, KURIHARA C, OKUBO M, NAKANO Y, KUSA Y, YOSHIKAWA A, INABE K, UENO K, OBATA Y. Genetic Materials at the Gene Engineering Division, RIKEN BioResource Center. Exp Anim 2010; 59:115-24. [DOI: 10.1538/expanim.59.115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Kazunari K. YOKOYAMA
- Gene Engineering Division, RIKEN BioResource Center
- Center of Excellence for Environmental Medicine, Graduate Institute of Medicine, Kaohsiung Medical University
- Department of Molecular Preventive Medicine, Graduate School of Medicine, The University of Tokyo
| | | | - Jianzhi PAN
- Gene Engineering Division, RIKEN BioResource Center
- Institute of Veterinary and Animal Husbandry, Zhejiang Academy of Agriculture Sciences
| | - Koji NAKADE
- Gene Engineering Division, RIKEN BioResource Center
| | | | - Hideyo UGAI
- Gene Engineering Division, RIKEN BioResource Center
- Division of Human Gene Therapy, Department of Medicine, University of Alabama at Birmingham
| | - Makoto KIMURA
- Gene Engineering Division, RIKEN BioResource Center
- Imamoto Cellular Dynamics Laboratory, RIKEN Advanced Science Institute
| | | | | | | | | | | | - Masato OKUBO
- Gene Engineering Division, RIKEN BioResource Center
| | - Yuri NAKANO
- Gene Engineering Division, RIKEN BioResource Center
| | - Yuka KUSA
- Gene Engineering Division, RIKEN BioResource Center
| | | | - Kumiko INABE
- Gene Engineering Division, RIKEN BioResource Center
| | - Kazuko UENO
- Gene Engineering Division, RIKEN BioResource Center
| | - Yuichi OBATA
- Gene Engineering Division, RIKEN BioResource Center
- RIKEN BioResource Center
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Hsu SN, Yonekura S, Ting CY, Robertson HM, Iwai Y, Uemura T, Lee CH, Chiba A. Conserved alternative splicing and expression patterns of arthropod N-cadherin. PLoS Genet 2009; 5:e1000441. [PMID: 19343204 PMCID: PMC2655722 DOI: 10.1371/journal.pgen.1000441] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Accepted: 03/02/2009] [Indexed: 12/04/2022] Open
Abstract
Metazoan development requires complex mechanisms to generate cells with diverse function. Alternative splicing of pre-mRNA not only expands proteomic diversity but also provides a means to regulate tissue-specific molecular expression. The N-Cadherin gene in Drosophila contains three pairs of mutually-exclusive alternatively-spliced exons (MEs). However, no significant differences among the resulting protein isoforms have been successfully demonstrated in vivo. Furthermore, while the N-Cadherin gene products exhibit a complex spatiotemporal expression pattern within embryos, its underlying mechanisms and significance remain unknown. Here, we present results that suggest a critical role for alternative splicing in producing a crucial and reproducible complexity in the expression pattern of arthropod N-Cadherin. We demonstrate that the arthropod N-Cadherin gene has maintained the three sets of MEs for over 400 million years using in silico and in vivo approaches. Expression of isoforms derived from these MEs receives precise spatiotemporal control critical during development. Both Drosophila and Tribolium use ME-13a and ME-13b in “neural” and “mesodermal” splice variants, respectively. As proteins, either ME-13a- or ME-13b-containing isoform can cell-autonomously rescue the embryonic lethality caused by genetic loss of N-Cadherin. Ectopic muscle expression of either isoform beyond the time it normally ceases leads to paralysis and lethality. Together, our results offer an example of well-conserved alternative splicing increasing cellular diversity in metazoans. Animal development requires complex mechanisms to generate many different types of cells. Alternative splicing is a process by which a single gene could produce several protein variants under particular circumstances. It is a useful means to generate a diversified set of proteins in different cell types. In this report, we showed that the alternative splicing of the arthropod N-Cadherin gene has been maintained for over 400 million years. The switch of expression patterns of two distinct variants is also well conserved in arthropods. As proteins, these two N-Cadherin splice variants have similar ability to rescue the embryonic lethality caused by genetic loss of N-Cadherin. However, when the expression of either isoforms was prolonged in muscles where the endogenous expression ceased beyond certain stages, it leads to larval lethality, suggesting the importance of precise spatiotemporal regulation of N-Cadherin splice-variant expression. This finding is particularly important because it offers an example of well-conserved alternative splicing increasing cellular diversity in animals.
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Affiliation(s)
- Shu-Ning Hsu
- Neuroscience Program, University of Illinois, Urbana, Illinois, United States of America.
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Bicaudal-C associates with a Trailer Hitch/Me31B complex and is required for efficient Gurken secretion. Dev Biol 2009; 328:160-72. [PMID: 19389362 DOI: 10.1016/j.ydbio.2009.01.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 01/05/2009] [Accepted: 01/19/2009] [Indexed: 01/15/2023]
Abstract
Bicaudal-C (Bic-C) is a multiple KH-domain RNA-binding protein required for Drosophila oogenesis and, maternally, for embryonic patterning. In early oogenesis, Bic-C negatively regulates target mRNAs, including Bic-C, by recruiting the CCR4 deadenylase through a direct association with its NOT3 subunit. Here, we identify a novel function for Bic-C in secretion of the TGF-alpha homolog Gurken (Grk). In Bic-C mutant egg chambers, Grk is sequestered within actin-coated structures during mid-oogenesis. As a consequence, Egfr signalling is not efficiently activated in the dorsal-anterior follicle cells. This phenotype is strikingly similar to that of trailer hitch (tral) mutants. Consistent with the idea that Bic-C and Tral act together in Grk secretion, Bic-C co-localizes with Tral within cytoplasmic granules, and can be co-purified with multiple protein components of a Tral mRNP complex. Taken together, our results implicate translational regulation by Bic-C and Tral in the secretory pathway.
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Shippy TD, Yeager SJ, Denell RE. The Tribolium spineless ortholog specifies both larval and adult antennal identity. Dev Genes Evol 2008; 219:45-51. [PMID: 19030877 DOI: 10.1007/s00427-008-0261-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 09/29/2008] [Indexed: 11/24/2022]
Abstract
The morphology of insect antennae varies widely among species, but our understanding of antennal development comes almost solely from studies of one species-the fruit fly, Drosophila melanogaster. Moreover, this knowledge applies mostly to adult structures, since Drosophila lacks external larval appendages. In contrast to Drosophila, the red flour beetle, Tribolium castaneum, has both larval and adult antennae, which are very different from one another in morphology. Thus, Tribolium provides an ideal system to compare modes of antennal development both within and between species. Here, we report that the Tribolium ortholog of spineless (Tc-ss) is required in both the larval and adult antennae. Knockdown of Tc-ss by RNAi during either larval or imaginal development causes transformation of the distal portion of the antennae to legs. Thus, the function of ss is conserved between Drosophila and Tribolium with respect to adult antennal specification and also between Tribolium larval and adult antennal development. The similarity of the Tc-ss RNAi phenotype to that of a classically described Tribolium mutation, antennapedia (ap) (of no relationship to the Drosophila Hox gene of the same name), led us to characterize the original ap mutation and two newly identified ap alleles. Our mapping and phenotypic data suggest that Tc-ss is the best candidate for the ap locus. These results represent a first step in characterizing larval and adult antennal patterning in Tribolium, which should provide important insights into the evolution of insect antennal development.
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Affiliation(s)
- Teresa D Shippy
- Arthropod Genomics Center, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
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