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Walters R, Manion J, Neely GG. Dissecting Motor Neuron Disease With Drosophila melanogaster. Front Neurosci 2019; 13:331. [PMID: 31031583 PMCID: PMC6473072 DOI: 10.3389/fnins.2019.00331] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 03/21/2019] [Indexed: 12/13/2022] Open
Abstract
Motor Neuron Disease (MND) typically affects patients during the later stages of life, and thus, MND is having an increasingly devastating impact on diagnosed individuals, their families and society. The umbrella term MND refers to diseases which cause the progressive loss of upper and/or lower motor neurons and a subsequent decrease in motor ability such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). The study of these diseases is complex and has recently involved the use of genome-wide association studies (GWAS). However, in the case of MND, it has been difficult to identify the complex genetics involved in subtypes, and functional investigation of new candidate disease genes is warranted. Drosophila is a powerful model for addressing these complex diseases. The UAS/Gal4/Gal80 system allows for the upregulation of Drosophila genes, the “knockdown” of genes and the ectopic expression of human genes or mutations in a tissue-specific manner; often resulting in Drosophila models which exhibit typical MND disease pathologies. These can then be further interrogated to identify disease-modifying genes or mutations and disease pathways. This review will discuss two common MNDs and the current Drosophila models which are being used to research their genetic basis and the different pathologies of MND.
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Affiliation(s)
- Rachel Walters
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - John Manion
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - G Gregory Neely
- Dr. John and Anne Chong Lab for Functional Genomics, Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
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Brabcová J, Demianová Z, Kindl J, Pichová I, Valterová I, Zarevúcka M. Characterisation of Acetyl-CoA Thiolase: The First Enzyme in the Biosynthesis of Terpenic Sex Pheromone Components in the Labial Gland ofBombus terrestris. Chembiochem 2015; 16:1047-51. [DOI: 10.1002/cbic.201402591] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Indexed: 11/10/2022]
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3
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Diaper DC, Adachi Y, Sutcliffe B, Humphrey DM, Elliott CJ, Stepto A, Ludlow ZN, Vanden Broeck L, Callaerts P, Dermaut B, Al-Chalabi A, Shaw CE, Robinson IM, Hirth F. Loss and gain of Drosophila TDP-43 impair synaptic efficacy and motor control leading to age-related neurodegeneration by loss-of-function phenotypes. Hum Mol Genet 2013; 22:1539-57. [PMID: 23307927 PMCID: PMC3605831 DOI: 10.1093/hmg/ddt005] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 01/03/2013] [Indexed: 12/12/2022] Open
Abstract
Cytoplasmic accumulation and nuclear clearance of TDP-43 characterize familial and sporadic forms of amyotrophic lateral sclerosis and frontotemporal lobar degeneration, suggesting that either loss or gain of TDP-43 function, or both, cause disease formation. Here we have systematically compared loss- and gain-of-function of Drosophila TDP-43, TAR DNA Binding Protein Homolog (TBPH), in synaptic function and morphology, motor control, and age-related neuronal survival. Both loss and gain of TBPH severely affect development and result in premature lethality. TBPH dysfunction caused impaired synaptic transmission at the larval neuromuscular junction (NMJ) and in the adult. Tissue-specific knockdown together with electrophysiological recordings at the larval NMJ also revealed that alterations of TBPH function predominantly affect pre-synaptic efficacy, suggesting that impaired pre-synaptic transmission is one of the earliest events in TDP-43-related pathogenesis. Prolonged loss and gain of TBPH in adults resulted in synaptic defects and age-related, progressive degeneration of neurons involved in motor control. Toxic gain of TBPH did not downregulate or mislocalize its own expression, indicating that a dominant-negative effect leads to progressive neurodegeneration also seen with mutational inactivation of TBPH. Together these data suggest that dysfunction of Drosophila TDP-43 triggers a cascade of events leading to loss-of-function phenotypes whereby impaired synaptic transmission results in defective motor behavior and progressive deconstruction of neuronal connections, ultimately causing age-related neurodegeneration.
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Affiliation(s)
| | | | - Ben Sutcliffe
- Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth, PlymouthPL6 8BU, UK
| | | | | | | | | | - Lies Vanden Broeck
- Laboratory of Behavioural & Developmental Genetics, Centre for Human Genetics, University of Leuven & VIB Centre for the Biology of Disease, Leuven3000, Belgium
| | - Patrick Callaerts
- Laboratory of Behavioural & Developmental Genetics, Centre for Human Genetics, University of Leuven & VIB Centre for the Biology of Disease, Leuven3000, Belgium
| | - Bart Dermaut
- Laboratory of Behavioural & Developmental Genetics, Centre for Human Genetics, University of Leuven & VIB Centre for the Biology of Disease, Leuven3000, Belgium
- INSERM U744, Pasteur Institute of Lille, University of Lille North of France, Lille, France
| | - Ammar Al-Chalabi
- Department of Clinical Neuroscience, Institute of Psychiatry, MRC Centre for Neurodegeneration Research, King's College London, LondonSE5 8AF, UK
| | - Christopher E. Shaw
- Department of Clinical Neuroscience, Institute of Psychiatry, MRC Centre for Neurodegeneration Research, King's College London, LondonSE5 8AF, UK
| | - Iain M. Robinson
- Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth, PlymouthPL6 8BU, UK
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4
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Kishita Y, Tsuda M, Aigaki T. Impaired fatty acid oxidation in a Drosophila model of mitochondrial trifunctional protein (MTP) deficiency. Biochem Biophys Res Commun 2012; 419:344-9. [DOI: 10.1016/j.bbrc.2012.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 02/03/2012] [Indexed: 11/16/2022]
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5
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miRNA-mediated feedback inhibition of JAK/STAT morphogen signalling establishes a cell fate threshold. Nat Cell Biol 2011; 13:1062-9. [PMID: 21857668 PMCID: PMC3167036 DOI: 10.1038/ncb2316] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 06/24/2011] [Indexed: 12/20/2022]
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6
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Lukacsovich T, Hamada N, Miyazaki S, Kimpara A, Yamamoto D. A new versatile gene-trap vector for insect transgenics. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2008; 69:168-175. [PMID: 18949801 DOI: 10.1002/arch.20276] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A new piggyBac-based gene-trap vector, pB-GT1, was constructed. pB-GT1 contains three marker genes, dsRed, Gal4, and EGFP. dsRed is under the control of the constitutive 3xP3 promoter, which induces dsRed expression wherever the vector is inserted in the host genome. The Gal4 sequence has no promoter but is preceded by the splice acceptor site so that it can be transcribed as a transcript fused with the host exon 5' to the insertion site. EGFP is driven by the constitutive ie+hr promoter but lacks a poly(A)(+) signal sequence, and thus the EGFP expression is detectable only when its transcript is fused with the host exon 3' downstream of the insertion. By the microinjection of the vector into fertilized eggs, we obtained transgenic Drosophila with a single copy of pB-GT1, which was inserted into the first intron of the ovo gene. The female flies of this transgenic line are sterile, indicating that the insertion inactivated the ovo gene, generating a new allele of this locus, ovo(pB-GT1). RT-PCR analysis demonstrated that an ovo-Gal4-fusion transcript is produced in ovo(pB-GT1) flies. The fact that UAS-EGFP reporter expression was detected in ovo(pB-GT1) germ cells in a pattern similar to that reported for wild-type ovo indicates that functional Gal4 is expressed via pB-GT1, recapitulating the endogenous expression pattern of the trapped gene. pB-GT1 is thus useful in insect genomics for the efficient assignment of functions of individual genes.
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Affiliation(s)
- Tamas Lukacsovich
- Tohoku University Graduate School of Life Sciences, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan
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Allen MJ, Drummond JA, Sweetman DJ, Moffat KG. Analysis of two P-element enhancer-trap insertion lines that show expression in the giant fibre neuron of Drosophila melanogaster. GENES BRAIN AND BEHAVIOR 2006; 6:347-58. [PMID: 16879616 DOI: 10.1111/j.1601-183x.2006.00263.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The giant fibre system (GFS) of Drosophila is a simple neural circuit that mediates escape responses in adult flies. Here we report the initial characterization of two genes that are preferentially expressed in the GFS. Two P-element insertion lines, carrying the GAL4 transcriptional activator, were identified that exhibited pronounced expression in elements of the GFS and relatively low levels elsewhere within the adult central nervous system. Genomic DNA flanking the P-element insertion site was recovered from each of these lines, sequenced, and nearby transcripts identified and confirmed to exhibit GFS expression by in situ hybridization. This analysis revealed that these P-elements were in previously characterized genes. Line P[GAL4]-A307 has an insert in the gene short stop for which we have identified a novel transcript, while line P[GAL4]-141 has an insert in the transcription factor ken and barbie. Here we show that ken and barbie mutants have defects in escape behaviour, behavioural responses to visual stimuli and synaptic functions in the GFS. We have therefore revealed a neural role for a transcription factor that previously had no implicated neural function.
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Affiliation(s)
- M J Allen
- Department of Biological Sciences, University of Warwick, Coventry, and Department of Biosciences, University of Kent, Canterbury, United Kingdom
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Arbouzova NI, Bach EA, Zeidler MP. Ken & barbie selectively regulates the expression of a subset of Jak/STAT pathway target genes. Curr Biol 2006; 16:80-8. [PMID: 16401426 DOI: 10.1016/j.cub.2005.11.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 11/06/2005] [Accepted: 11/07/2005] [Indexed: 11/24/2022]
Abstract
A limited number of evolutionarily conserved signal transduction pathways are repeatedly reused during development to regulate a wide range of processes. Here we describe a new negative regulator of JAK/STAT signaling and identify a potential mechanism by which the pleiotropy of responses resulting from pathway activation is generated in vivo. As part of a genetic interaction screen, we have identified Ken & Barbie (Ken) , which is an ortholog of the mammalian proto-oncogene BCL6 , as a negative regulator of the JAK/STAT pathway. Ken genetically interacts with the pathway in vivo and recognizes a DNA consensus sequence overlapping that of STAT92E in vitro. Tissue culture-based assays demonstrate the existence of Ken-sensitive and Ken-insensitive STAT92E binding sites, while ectopically expressed Ken is sufficient to downregulate a subset of JAK/STAT pathway target genes in vivo. Finally, we show that endogenous Ken specifically represses JAK/STAT-dependent expression of ventral veins lacking (vvl) in the posterior spiracles. Ken therefore represents a novel regulator of JAK/STAT signaling whose dynamic spatial and temporal expression is capable of selectively modulating the transcriptional repertoire elicited by activated STAT92E in vivo.
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Affiliation(s)
- Natalia I Arbouzova
- Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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Davis GK, D'Alessio JA, Patel NH. Pax3/7 genes reveal conservation and divergence in the arthropod segmentation hierarchy. Dev Biol 2005; 285:169-84. [PMID: 16083872 DOI: 10.1016/j.ydbio.2005.06.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2005] [Revised: 06/06/2005] [Accepted: 06/13/2005] [Indexed: 11/15/2022]
Abstract
Several features of Pax3/7 gene expression are shared among distantly related insects, including pair-rule, segment polarity, and neural patterns. Recent data from arachnids imply that roles in segmentation and neurogenesis are likely to be played by Pax3/7 genes in all arthropods. To further investigate Pax3/7 genes in non-insect arthropods, we isolated two monoclonal antibodies that recognize the products of Pax3/7 genes in a wide range of taxa, allowing us to quickly survey Pax3/7 expression in all four major arthropod groups. Epitope analysis reveals that these antibodies react to a small subset of Paired-class homeodomains, which includes the products of all known Pax3/7 genes. Using these antibodies, we find that Pax3/7 genes in crustaceans are expressed in an early broad and, in one case, dynamic domain followed by segmental stripes, while myriapods and chelicerates exhibit segmental stripes that form early in the posterior-most part of the germ band. This suggests that Pax3/7 genes acquired their role in segmentation deep within, or perhaps prior to, the arthropod lineage. However, we do not detect evidence of pair-rule patterning in either myriapods or chelicerates, suggesting that the early pair-rule expression pattern of Pax3/7 genes in insects may have been acquired within the crustacean-hexapod lineage.
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Affiliation(s)
- Gregory K Davis
- Committee on Developmental Biology, University of Chicago, Chicago, IL 60637, USA
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10
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Ayala YM, Pantano S, D'Ambrogio A, Buratti E, Brindisi A, Marchetti C, Romano M, Baralle FE. Human, Drosophila, and C.elegans TDP43: Nucleic Acid Binding Properties and Splicing Regulatory Function. J Mol Biol 2005; 348:575-88. [PMID: 15826655 DOI: 10.1016/j.jmb.2005.02.038] [Citation(s) in RCA: 268] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Revised: 02/17/2005] [Accepted: 02/20/2005] [Indexed: 11/21/2022]
Abstract
TAR DNA binding protein (TDP43), a highly conserved heterogeneous nuclear ribonucleoprotein, was found to down-regulate splicing of the exon 9 cystic fibrosis transmembrane conductance regulator (CFTR) through specific binding to a UG-rich polymorphic region upstream of the 3' splice site. Despite the emergence of new information regarding the protein's nuclear localization and splicing regulatory activity, TDP43's role in cells remains elusive. To investigate the function of human TDP43 and its homologues, we cloned and characterized the proteins from Drosophila melanogaster and Caenorhabditis elegans. The proteins from human, fly, and worm show striking similarities in their nucleic acid binding specificity. We found that residues at two different positions, which show a strong conservation among TDP43 family members, are linked to the tight recognition of the target sequence. Our three-dimensional model of TDP43 in complex with a (UG)(m) sequence predicts that these residues make amino acid side-chain to base contacts. Moreover, our results suggest that Drosophila TDP43 is comparable to human TDP43 in regulating exon splicing. On the other hand, C.elegans TDP43 has no effect on exon recognition. TDP43 from C.elegans lacks the glycine-rich domain found at the carboxy terminus of the other two homologues. Mutants of human and fly TDP43 devoid of the C-terminal domain are likewise unable to affect splicing. Our studies suggest that the glycine-rich domain is essential for splicing regulation by human and fly TDP43.
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Affiliation(s)
- Youhna M Ayala
- International Centre for Genetic Engineering and Biotechnology (ICGEB) 34012 Trieste, Italy
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11
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Sinenko SA, Kim EK, Wynn R, Manfruelli P, Ando I, Wharton KA, Perrimon N, Mathey-Prevot B. Yantar, a conserved arginine-rich protein is involved in Drosophila hemocyte development. Dev Biol 2004; 273:48-62. [PMID: 15302597 DOI: 10.1016/j.ydbio.2004.05.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 05/06/2004] [Accepted: 05/07/2004] [Indexed: 10/26/2022]
Abstract
To identify novel factors involved in Drosophila hematopoiesis, we screened a collection of lethal recessive mutations that also affected normal hemocyte composition in larvae. We present the characterization of the gene yantar (ytr) for which we isolated null and hypomorphic mutations that were associated with severe defects in hemocyte differentiation and proliferation; ytr is predominantly expressed in the hematopoietic tissue during larval development and encodes an evolutionary conserved protein which is predominantly localized in the nucleus. The hematopoietic phenotype in ytr mutants is consistent with a defect or block in differentiation of precursor hemocytes: mutant larvae have enlarged lymph glands (LGs) and have an excess of circulating hemocytes. In addition, many cells exhibit both lamellocyte and crystal cell markers. Ytr function has been preserved in evolution as hematopoietic specific expression of the Drosophila or mouse Ytr proteins rescue the differentiation defects in mutant hemocytes.
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Affiliation(s)
- Sergey A Sinenko
- Division of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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12
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Wang HY, Wang IF, Bose J, Shen CKJ. Structural diversity and functional implications of the eukaryotic TDP gene family. Genomics 2004; 83:130-9. [PMID: 14667816 DOI: 10.1016/s0888-7543(03)00214-3] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TDP-43 is an RNA-binding protein that functions in mammalian cells in transcriptional repression and exon skipping. The gene encoding TDP-43 (HGMW-approved gene symbol TARDBP) is conserved in human, mouse, Drosophila melanogaster, and Caenorhabditis elegans. Sequence comparison of the coding regions of the TDP genes among the four taxa reveals an extraordinarily low rate of sequence divergence, suggesting that the TDP genes carry out essential functions in these organisms. With DNA transfection assay, we have established the importance of the glycine-rich domain for the exon-skipping activity of TDP-43. Both human and mouse TDP genes belong to a gene family that also consists of a number of processed pseudogenes. Interestingly, combined database analysis and cDNA cloning have demonstrated that the primary transcript of the mammalian TDP genes undergoes alternative splicing to generate 11 mRNAs, including the one encoding TDP-43. Eight of the 11 splicing events involved the use of four each of the 5'-donor and 3'-acceptor sites, all of which reside within the last exon of the TDP-43 mRNA. The existence of multispliced isoforms of TDP-encoded proteins provides further support for the functional complexity of the eukaryotic TDP genes.
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Affiliation(s)
- Hurng-Yi Wang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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13
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Lukacsovich T, Yuge K, Awano W, Asztalos Z, Kondo S, Juni N, Yamamoto D. The ken and barbie gene encoding a putative transcription factor with a BTB domain and three zinc finger motifs functions in terminalia development of Drosophila. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2003; 54:77-94. [PMID: 14518006 DOI: 10.1002/arch.10105] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mutations in the ken and barbie locus are accompanied by the malformation of terminalia in adult Drosophila. Male and female genitalia often remain inside the body, and the same portions of genitalia and analia are missing in a fraction of homozygous flies. Rotated and/or duplicated terminalia are also observed. Terminalia phenotypes are enhanced by mutations in the gap gene tailless, the homeobox gene caudal, and the decapentaplegic gene that encodes a TGFbeta-like morphogen. The ken and barbie gene encodes a protein with three CCHH-type zinc finger motifs that are conserved in several transcription factors such as Krüppel and BCL-6. All defects in ken and barbie mutants are fully rescued by the expression of a wild-type genomic construct, which establishes the causality between phenotypes and the gene.
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Affiliation(s)
- Tamas Lukacsovich
- ERATO Yamamoto Behavior Genes Project at Mitsubishi Kagaku Institute of Life Sciences, Tokyo, Japan
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14
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Wang IF, Reddy NM, Shen CKJ. Higher order arrangement of the eukaryotic nuclear bodies. Proc Natl Acad Sci U S A 2002; 99:13583-8. [PMID: 12361981 PMCID: PMC129717 DOI: 10.1073/pnas.212483099] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2002] [Accepted: 08/12/2002] [Indexed: 11/18/2022] Open
Abstract
The nuclei of eukaryotic cells consist of discrete substructures. These substructures include the nuclear bodies, which have been implicated in a number of biological processes such as transcription and splicing. However, for most nuclear bodies, the details of involvement in these processes in relation to their three-dimensional distributions in the nucleus are still unclear. Through the analysis of TDP, a protein functional in both transcriptional repression and alternative splicing, we have identified a new category of nuclear bodies within which the TDP molecules reside. Remarkably, the TDP bodies (TBs) colocalize or overlap with several different types of nuclear bodies previously suggested to function in transcription or splicing. Of these nuclear bodies, the Gemini of coiled bodies (GEM) seems to associate with TB through the interaction between survival motor neuron (SMN) protein and TDP. Furthermore, TB sometimes appears to be the bridge of two or more of these other nuclear bodies. Our data suggest the existence of a hierarchy and possibly functional arrangement of the nuclear bodies within the eukaryotic nuclei.
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Affiliation(s)
- I-Fan Wang
- Institute of Molecular Biology, Academia Sinica, National Taiwan University, Taipei, Taiwan 115, Republic of China
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15
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Buratti E, Baralle FE. Characterization and functional implications of the RNA binding properties of nuclear factor TDP-43, a novel splicing regulator of CFTR exon 9. J Biol Chem 2001; 276:36337-43. [PMID: 11470789 DOI: 10.1074/jbc.m104236200] [Citation(s) in RCA: 499] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Variations in a polymorphic (TG)m sequence near exon 9 of the human CFTR gene have been associated with variable proportions of exon skipping and occurrence of disease. We have recently identified nuclear factor TDP-43 as a novel splicing regulator capable of binding to this element in the CFTR pre-mRNA and inhibiting recognition of the neighboring exon. In this study we report the dissection of the RNA binding properties of TDP-43 and their functional implications in relationship with the splicing process. Our results show that this protein contains two fully functional RNA recognition motif (RRM) domains with distinct RNA/DNA binding characteristics. Interestingly, TDP-43 can bind a minimum number of six UG (or TG) single-stranded dinucleotide stretches, and binding affinity increases with the number of repeats. In particular, the highly conserved Phe residues in the first RRM region play a key role in nucleic acid recognition.
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Affiliation(s)
- E Buratti
- International Center for Genetic Engineering and Biotechnology (ICGEB) 34012 Trieste, Italy
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16
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Abstract
We describe four members of the tetraspanin/TM4SF superfamily of proteins that were identified in expressed sequence tag projects on the antennae of Manduca sexta moths and Apis mellifera honey bees. The three moth genes are expressed in the sensillar epithelium of male antennae, and some are expressed in female antennae, haemocytes, wing scale cell primordia and/or embryonic tissues. These proteins are probably involved in diverse cellular processes, much like their vertebrate homologues. A phylogenetic analysis of all known tetraspanins, including thirty-seven members of the superfamily revealed by the Drosophila melanogaster genome and twenty in the nematode Caenorhabditis elegans genome, reveals some phylum-specific gene amplification, in particular a contiguous array of eighteen genes in the D. melanogaster genome.
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Affiliation(s)
- E Todres
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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17
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Usui-Aoki K, Ito H, Ui-Tei K, Takahashi K, Lukacsovich T, Awano W, Nakata H, Piao ZF, Nilsson EE, Tomida J, Yamamoto D. Formation of the male-specific muscle in female Drosophila by ectopic fruitless expression. Nat Cell Biol 2000; 2:500-6. [PMID: 10934470 DOI: 10.1038/35019537] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Drosophila fruitless (fru) gene product Fru has been postulated to be a neural sex-determination factor that directs the development of at least two male-specific characteristics, namely courtship behaviour and formation of the muscle of Lawrence (MOL). The fru gene encodes a putative transcription factor with a BTB domain and two zinc-finger motifs, and with consensus Tra-binding sequences. The binding of Tra to these sequences results in sex-specific alternative splicing of the fru mRNA, leading to production of the 'male-type' or 'female-type' Fru protein. We show here that the Fru protein is not detected in the female central nervous system (CNS), despite the similar level of expression of fru mRNA in both male and female CNS. As ectopic expression of both the 'male-type' (with the sequence for the amino-terminal extension) and 'female-type' (without the sequence for the amino-terminal extension) fru cDNA can induce formation of the MOL in females, the presence or absence of the Fru protein, and not its sex-specific structure, seems to be responsible for the sexually dimorphic actions of the fru gene.
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Affiliation(s)
- K Usui-Aoki
- School of Human Sciences and Advanced Research Institute for Science and Engineering, Waseda University, 2-579-15, Mikajima, Tokorozawa 359-1192, Japan
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18
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Ohlstein B, Lavoie CA, Vef O, Gateff E, McKearin DM. The Drosophila cystoblast differentiation factor, benign gonial cell neoplasm, is related to DExH-box proteins and interacts genetically with bag-of-marbles. Genetics 2000; 155:1809-19. [PMID: 10924476 PMCID: PMC1461197 DOI: 10.1093/genetics/155.4.1809] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Selection of asymmetric cell fates can involve both intrinsic and extrinsic factors. Previously we have identified the bag-of-marbles (bam) gene as an intrinsic factor for cystoblast fate in Drosophila germline cells and shown that it requires active product from the benign gonial cell neoplasm (bgcn) gene. Here we present the cloning and characterization of bgcn. The predicted Bgcn protein is related to the DExH-box family of RNA-dependent helicases but lacks critical residues for ATPase and helicase functions. Expression of the bgcn gene is extremely limited in ovaries but, significantly, bgcn mRNA is expressed in a very limited number of germline cells, including the stem cells. Also, mutations in bgcn dominantly enhance a bam mutant phenotype, further corroborating the interdependence of these two genes' functions. On the basis of known functions of DExH-box proteins, we propose that Bgcn and Bam may be involved in regulating translational events that are necessary for activation of the cystoblast differentiation program.
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Affiliation(s)
- B Ohlstein
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA
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Misener SR, Walker VK. Extraordinarily high density of unrelated genes showing overlapping and intraintronic transcription units. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1492:269-70. [PMID: 10858562 DOI: 10.1016/s0167-4781(00)00096-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The cloning of pyrroline 5-carboxylate reductase from Drosophila melanogaster was accomplished by cDNA complementation of an Escherichia coli proline auxotroph. The corresponding P5cr gene is tightly clustered with three other expressed coding regions. A bidirectional promoter, an overlapping 3'UTR and an intraintronic sequence may all be found in only 4.3 kb, making this the most densely clustered region of unrelated genes in any eukaryote.
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Affiliation(s)
- S R Misener
- Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6
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Abstract
In the present work we show that in the Drosophila genome (which covers a 37-51% GC range at a DNA size of approx.50kb) a linear correlation holds between GC (or GC(3)50kb) genomic sequences embedding them. This correlation allows us to position the two compositional distributions of (a) coding sequences, and (b) of long DNA segments relative to each other and to calculate gene concentration across the compositional range of the Drosophila genome. Using this approach, we show that gene concentration increases with increasing GC of the regions embedding the genes, reaching a 7-fold higher level in the GC-richest regions compared with the GC-poorest regions. The gene distribution of the Drosophila genome is, therefore, similar to (although less striking than) that of the human genome, whereas it is very different from those of the Arabidopsis genome, which has about the same size as the Drosophila genome.
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Affiliation(s)
- K Jabbari
- Laboratoire de Génétique Moléculaire, Institut Jacques Monod, 2 Place Jussieu, 75005, Paris, France
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