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Diaz LR, Gil-Ranedo J, Jaworek KJ, Nsek N, Marques JP, Costa E, Hilton DA, Bieluczyk H, Warrington O, Hanemann CO, Futschik ME, Bossing T, Barros CS. Ribogenesis boosts controlled by HEATR1-MYC interplay promote transition into brain tumour growth. EMBO Rep 2024; 25:168-197. [PMID: 38225354 PMCID: PMC10897169 DOI: 10.1038/s44319-023-00017-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 01/17/2024] Open
Abstract
Cell commitment to tumourigenesis and the onset of uncontrolled growth are critical determinants in cancer development but the early events directing tumour initiating cell (TIC) fate remain unclear. We reveal a single-cell transcriptome profile of brain TICs transitioning into tumour growth using the brain tumour (brat) neural stem cell-based Drosophila model. Prominent changes in metabolic and proteostasis-associated processes including ribogenesis are identified. Increased ribogenesis is a known cell adaptation in established tumours. Here we propose that brain TICs boost ribogenesis prior to tumour growth. In brat-deficient TICs, we show that this dramatic change is mediated by upregulated HEAT-Repeat Containing 1 (HEATR1) to promote ribosomal RNA generation, TIC enlargement and onset of overgrowth. High HEATR1 expression correlates with poor glioma patient survival and patient-derived glioblastoma stem cells rely on HEATR1 for enhanced ribogenesis and tumourigenic potential. Finally, we show that HEATR1 binds the master growth regulator MYC, promotes its nucleolar localisation and appears required for MYC-driven ribogenesis, suggesting a mechanism co-opted in ribogenesis reprogramming during early brain TIC development.
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Affiliation(s)
- Laura R Diaz
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Jon Gil-Ranedo
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Karolina J Jaworek
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
- School of Biological Sciences, Bangor University, LL57 2UW, Bangor, UK
| | - Nsikan Nsek
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Joao Pinheiro Marques
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Eleni Costa
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - David A Hilton
- Department of Cellular and Anatomical Pathology, University Hospitals Plymouth, PL6 8DH, Plymouth, UK
| | - Hubert Bieluczyk
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Oliver Warrington
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, London, UK
| | - C Oliver Hanemann
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Matthias E Futschik
- School of Biomedical Sciences, Faculty of Health, Derriford Research Facility, University of Plymouth, PL6 8BU, Plymouth, UK
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3004-504, Coimbra, Portugal
| | - Torsten Bossing
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK
| | - Claudia S Barros
- Peninsula Medical School, Faculty of Health, John Bull Building, University of Plymouth, PL6 8BU, Plymouth, UK.
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Gao Y, Liu S, Jia Q, Wu L, Yuan D, Li EY, Feng Q, Wang G, Palli SR, Wang J, Li S. Juvenile hormone membrane signaling phosphorylates USP and thus potentiates 20-hydroxyecdysone action in Drosophila. Sci Bull (Beijing) 2022; 67:186-197. [PMID: 36546012 DOI: 10.1016/j.scib.2021.06.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/10/2021] [Accepted: 06/15/2021] [Indexed: 01/06/2023]
Abstract
Juvenile hormone (JH) and 20-hydroxyecdysone (20E) coordinately regulate development and metamorphosis in insects. Two JH intracellular receptors, methoprene-tolerant (Met) and germ-cell expressed (Gce), have been identified in the fruit fly Drosophila melanogaster. To investigate JH membrane signaling pathway without the interference from JH intracellular signaling, we characterized phosphoproteome profiles of the Met gce double mutant in the absence or presence of JH in both chronic and acute phases. Functioning through a potential receptor tyrosine kinase and phospholipase C pathway, JH membrane signaling activated protein kinase C (PKC) which phosphorylated ultraspiracle (USP) at Ser35, the PKC phosphorylation site required for the maximal action of 20E through its nuclear receptor complex EcR-USP. The uspS35A mutant, in which Ser was replaced with Ala at position 35 by genome editing, showed decreased expression of Halloween genes that are responsible for ecdysone biosynthesis and thus attenuated 20E signaling that delayed developmental timing. The uspS35A mutant also showed lower Yorkie activity that reduced body size. Altogether, JH membrane signaling phosphorylates USP at Ser35 and thus potentiates 20E action that regulates the normal fly development. This study helps better understand the complex JH signaling network.
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Affiliation(s)
- Yue Gao
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China; Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514779, China
| | - Suning Liu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Qiangqiang Jia
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Lixian Wu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Dongwei Yuan
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Emma Y Li
- International Department, The Affiliated High School of South China Normal University, Guangzhou 510631, China
| | - Qili Feng
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Guirong Wang
- Lingnan Guangdong Laboratory of Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Subba R Palli
- Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington 40546, USA
| | - Jian Wang
- Department of Entomology, University of Maryland, College Park 20742, USA.
| | - Sheng Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China; Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou 514779, China.
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3
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Endow SA, Miller SE, Ly PT. Mitochondria-enriched protrusions are associated with brain and intestinal stem cells in Drosophila. Commun Biol 2019; 2:427. [PMID: 31799429 PMCID: PMC6874589 DOI: 10.1038/s42003-019-0671-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 11/04/2019] [Indexed: 12/12/2022] Open
Abstract
Brain stem cells stop dividing in late Drosophila embryos and begin dividing again in early larvae after feeding induces reactivation. Quiescent neural stem cells (qNSCs) display an unusual cytoplasmic protrusion that is no longer present in reactivated NSCs. The protrusions join the qNSCs to the neuropil, brain regions that are thought to maintain NSCs in an undifferentiated state, but the function of the protrusions is not known. Here we show that qNSC protrusions contain clustered mitochondria that are likely maintained in position by slow forward-and-backward microtubule growth. Larvae treated with a microtubule-stabilizing drug show bundled microtubules and enhanced mitochondrial clustering in NSCs, together with reduced qNSC reactivation. We further show that intestinal stem cells contain mitochondria-enriched protrusions. The qNSC and intestinal stem-cell protrusions differ from previously reported cytoplasmic extensions by forming stem-cell-to-niche mitochondrial bridges that could potentially both silence genes and sense signals from the stem cell niche.
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Affiliation(s)
- Sharyn A. Endow
- Programme in Neuroscience and Behavioural Disorders, Duke-NUS Medical School, Singapore, 169857 Singapore
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710 USA
| | - Sara E. Miller
- Department of Pathology, Duke University Medical Center, Durham, NC 27710 USA
| | - Phuong Thao Ly
- Programme in Neuroscience and Behavioural Disorders, Duke-NUS Medical School, Singapore, 169857 Singapore
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Maternal Proteins That Are Phosphoregulated upon Egg Activation Include Crucial Factors for Oogenesis, Egg Activation and Embryogenesis in Drosophila melanogaster. G3-GENES GENOMES GENETICS 2018; 8:3005-3018. [PMID: 30012668 PMCID: PMC6118307 DOI: 10.1534/g3.118.200578] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Egg activation is essential for the successful transition from a mature oocyte to a developmentally competent egg. It consists of a series of events including the resumption and completion of meiosis, initiation of translation of some maternal mRNAs and destruction of others, and changes to the vitelline envelope. This major change of cell state is accompanied by large scale alteration in the oocyte’s phosphoproteome. We hypothesize that the cohort of proteins that are subject to phosphoregulation during egg activation are functionally important for processes before, during, or soon after this transition, potentially uniquely or as proteins carrying out essential cellular functions like those they do in other (somatic) cells. In this study, we used germline-specific RNAi to examine the function of 189 maternal proteins that are phosphoregulated during egg activation in Drosophila melanogaster. We identified 53 genes whose knockdown reduced or abolished egg production and caused a range of defects in ovarian morphology, as well as 51 genes whose knockdown led to significant impairment or abolishment of the egg hatchability. We observed different stages of developmental arrest in the embryos and various defects in spindle morphology and aberrant centrosome activities in the early arrested embryos. Our results, validated by the detection of multiple genes with previously-documented maternal effect phenotypes among the proteins we tested, revealed 15 genes with newly discovered roles in egg activation and early embryogenesis in Drosophila. Given that protein phosphoregulation is a conserved characteristic of this developmental transition, we suggest that the phosphoregulated proteins may provide a rich pool of candidates for the identification of important players in the egg-to-embryo transition.
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Drosophila mbm is a nucleolar myc and casein kinase 2 target required for ribosome biogenesis and cell growth of central brain neuroblasts. Mol Cell Biol 2014; 34:1878-91. [PMID: 24615015 DOI: 10.1128/mcb.00658-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proper cell growth is a prerequisite for maintaining repeated cell divisions. Cells need to translate information about intracellular nutrient availability and growth cues from energy-sensing organs into growth-promoting processes, such as sufficient supply with ribosomes for protein synthesis. Mutations in the mushroom body miniature (mbm) gene impair proliferation of neural progenitor cells (neuroblasts) in the central brain of Drosophila melanogaster. Yet the molecular function of Mbm has so far been unknown. Here we show that mbm does not affect the molecular machinery controlling asymmetric cell division of neuroblasts but instead decreases their cell size. Mbm is a nucleolar protein required for small ribosomal subunit biogenesis in neuroblasts. Accordingly, levels of protein synthesis are reduced in mbm neuroblasts. Mbm expression is transcriptionally regulated by Myc, which, among other functions, relays information from nutrient-dependent signaling pathways to ribosomal gene expression. At the posttranslational level, Mbm becomes phosphorylated by casein kinase 2 (CK2), which has an impact on localization of the protein. We conclude that Mbm is a new part of the Myc target network involved in ribosome biogenesis, which, together with CK2-mediated signals, enables neuroblasts to synthesize sufficient amounts of proteins required for proper cell growth.
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Extremes of lineage plasticity in the Drosophila brain. Curr Biol 2013; 23:1908-13. [PMID: 24055154 DOI: 10.1016/j.cub.2013.07.074] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/17/2013] [Accepted: 07/22/2013] [Indexed: 01/10/2023]
Abstract
An often-overlooked aspect of neural plasticity is the plasticity of neuronal composition, in which the numbers of neurons of particular classes are altered in response to environment and experience. The Drosophila brain features several well-characterized lineages in which a single neuroblast gives rise to multiple neuronal classes in a stereotyped sequence during development. We find that in the intrinsic mushroom body neuron lineage, the numbers for each class are highly plastic, depending on the timing of temporal fate transitions and the rate of neuroblast proliferation. For example, mushroom body neuroblast cycling can continue under starvation conditions, uncoupled from temporal fate transitions that depend on extrinsic cues reflecting organismal growth and development. In contrast, the proliferation rates of antennal lobe lineages are closely associated with organismal development, and their temporal fate changes appear to be cell cycle-dependent, such that the same numbers and types of uniglomerular projection neurons innervate the antennal lobe following various perturbations. We propose that this surprising difference in plasticity for these brain lineages is adaptive, given their respective roles as parallel processors versus discrete carriers of olfactory information.
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Emelyanov AV, Vershilova E, Ignatyeva MA, Pokrovsky DK, Lu X, Konev AY, Fyodorov DV. Identification and characterization of ToRC, a novel ISWI-containing ATP-dependent chromatin assembly complex. Genes Dev 2012; 26:603-14. [PMID: 22426536 DOI: 10.1101/gad.180604.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
SNF2-like motor proteins, such as ISWI, cooperate with histone chaperones in the assembly and remodeling of chromatin. Here we describe a novel, evolutionarily conserved, ISWI-containing complex termed ToRC (Toutatis-containing chromatin remodeling complex). ToRC comprises ISWI, Toutatis/TIP5 (TTF-I-interacting protein 5), and the transcriptional corepressor CtBP (C-terminal-binding protein). ToRC facilitates ATP-dependent nucleosome assembly in vitro. All three subunits are required for its maximal biochemical activity. The toutatis gene exhibits strong synthetic lethal interactions with CtBP. Thus, ToRC mediates, at least in part, biological activities of CtBP and Toutatis. ToRC subunits colocalize in euchromatic arms of polytene chromosomes. Furthermore, nuclear localization and precise distribution of ToRC in chromosomes are dependent on CtBP. ToRC is involved in CtBP-mediated regulation of transcription by RNA polymerase II in vivo. For instance, both Toutatis and CtBP are required for repression of genes of a proneural gene cluster, achaete-scute complex (AS-C), in Drosophila larvae. Intriguingly, native C-terminally truncated Toutatis isoforms do not associate with CtBP and localize predominantly to the nucleolus. Thus, Toutatis forms two alternative complexes that have differential distribution and can participate in distinct aspects of nuclear DNA metabolism.
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Affiliation(s)
- Alexander V Emelyanov
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Joyce EF, Williams BR, Xie T, Wu CT. Identification of genes that promote or antagonize somatic homolog pairing using a high-throughput FISH-based screen. PLoS Genet 2012; 8:e1002667. [PMID: 22589731 PMCID: PMC3349724 DOI: 10.1371/journal.pgen.1002667] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 03/07/2012] [Indexed: 12/22/2022] Open
Abstract
The pairing of homologous chromosomes is a fundamental feature of the meiotic cell. In addition, a number of species exhibit homolog pairing in nonmeiotic, somatic cells as well, with evidence for its impact on both gene regulation and double-strand break (DSB) repair. An extreme example of somatic pairing can be observed in Drosophila melanogaster, where homologous chromosomes remain aligned throughout most of development. However, our understanding of the mechanism of somatic homolog pairing remains unclear, as only a few genes have been implicated in this process. In this study, we introduce a novel high-throughput fluorescent in situ hybridization (FISH) technology that enabled us to conduct a genome-wide RNAi screen for factors involved in the robust somatic pairing observed in Drosophila. We identified both candidate "pairing promoting genes" and candidate "anti-pairing genes," providing evidence that pairing is a dynamic process that can be both enhanced and antagonized. Many of the genes found to be important for promoting pairing are highly enriched for functions associated with mitotic cell division, suggesting a genetic framework for a long-standing link between chromosome dynamics during mitosis and nuclear organization during interphase. In contrast, several of the candidate anti-pairing genes have known interphase functions associated with S-phase progression, DNA replication, and chromatin compaction, including several components of the condensin II complex. In combination with a variety of secondary assays, these results provide insights into the mechanism and dynamics of somatic pairing.
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Affiliation(s)
- Eric F. Joyce
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Benjamin R. Williams
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Tiao Xie
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- Image and Data Analysis Core, Harvard Medical School, Boston, Massachusetts, United States of America
| | - C.-ting Wu
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
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Protein landscape at Drosophila melanogaster telomere-associated sequence repeats. Mol Cell Biol 2012; 32:2170-82. [PMID: 22493064 DOI: 10.1128/mcb.00010-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The specific set of proteins bound at each genomic locus contributes decisively to regulatory processes and to the identity of a cell. Understanding of the function of a particular locus requires the knowledge of what factors interact with that locus and how the protein composition changes in different cell types or during the response to internal and external signals. Proteomic analysis of isolated chromatin segments (PICh) was developed as a tool to target, purify, and identify proteins associated with a defined locus and was shown to allow the purification of human telomeric chromatin. Here we have developed this method to identify proteins that interact with the Drosophila telomere-associated sequence (TAS) repeats. Several of the purified factors were validated as novel TAS-bound proteins by chromatin immunoprecipitation, and the Brahma complex was confirmed as a dominant modifier of telomeric position effect through the use of a genetic test. These results offer information on the efficacy of applying the PICh protocol to loci with sequence more complex than that found at human telomeres and identify proteins that bind to the TAS repeats, which might contribute to TAS biology and chromatin silencing.
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Wake-up-call, a lin-52 paralogue, and Always early, a lin-9 homologue physically interact, but have opposing functions in regulating testis-specific gene expression. Dev Biol 2011; 355:381-93. [PMID: 21570388 PMCID: PMC3123737 DOI: 10.1016/j.ydbio.2011.04.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 04/21/2011] [Accepted: 04/26/2011] [Indexed: 12/01/2022]
Abstract
A conserved multi-subunit complex (MybMuvB, MMB), regulates transcriptional activity of many different target genes in Drosophila somatic cells. A paralogous complex, tMAC, controls expression of at least 1500 genes in the male germline, and is essential for sperm production. The roles of specific subunits of tMAC, MMB or orthologous complexes in regulating target gene expression are not understood. MMB and orthologous complexes have Lin-52 as a subunit, but Lin-52 did not co-purify with tMAC. We identified wake-up-call (wuc), a lin-52 paralogue, via a physical interaction with the tMAC lin-9-related subunit Aly, and find that Wuc co-localises with known tMAC subunits. We show that wuc, like aly, is required for spermatogenesis. However, despite phenotypic similarities, the role of wuc is very different from that of previously characterised tMAC mutants. Unlike aly, loss of wuc results in only relatively mild defects in testis-specific gene expression. Strikingly, wuc loss of function partially rescues expression of target genes in aly mutant testes. We propose that wuc represses testis-specific gene expression, that this repression is counteracted by aly, and that aly and a testis-specific TFIID complex work together to promote high transcriptional activity of spermiogenic genes specifically in primary spermatocytes.
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Marinho J, Casares F, Pereira PS. The Drosophila Nol12 homologue viriato is a dMyc target that regulates nucleolar architecture and is required for dMyc-stimulated cell growth. Development 2011; 138:349-57. [PMID: 21177347 DOI: 10.1242/dev.054411] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The nucleolus is a subnuclear factory, the activity of which is required beyond ribosome biogenesis for the regulation of cell growth, death and proliferation. In both Drosophila and mammalian cells, the activity of the nucleolus is regulated by the proto-oncogene Myc. Myc induces the transcription of genes required for ribosome biogenesis and the synthesis of rRNA by RNA polymerase I, a nucleolar event that is rate limiting for cell growth. Here, we show that the fruit fly Nol12 homologue Viriato is a key determinant of nucleolar architecture that is required for tissue growth and cell survival during Drosophila development. We further show that viriato expression is controlled by Drosophila Myc (dMyc), and that the ability of dMyc to stimulate nucleolar and cellular growth depends on viriato expression. Therefore, viriato acts downstream of dMyc to ensure a coordinated nucleolar response to dMyc-induced growth and, thereby, normal organ development.
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Affiliation(s)
- Joana Marinho
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal
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Kim J, Lee S, Hwang M, Ko S, Min C, Kim-Ha J. Bunched specifically regulates alpha/beta mushroom body neuronal cell proliferation during metamorphosis. Neuroscience 2009; 161:46-52. [PMID: 19328837 DOI: 10.1016/j.neuroscience.2009.03.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 03/17/2009] [Accepted: 03/19/2009] [Indexed: 01/18/2023]
Abstract
In Drosophila, mushroom bodies are centers for higher order behavior. Mushroom body neurons consist of three distinct types of neuronal cells, alpha, alpha'/beta', and alpha/beta, which are all generated by the same neuroblasts. The mechanism by which a single neuroblast generates three different types of mushroom body neurons is a compelling area of research. Here, we report that bunched (bun) is expressed only in alpha/beta-type mushroom body neurons and that mutation of the bun gene only affects the development of alpha/beta neurons. Reduced bun expression causes decreased and premature arrest of neuroblast cell division, which results in reduced numbers of alpha/beta neurons and thin axon bundled formation. We propose that bun acts as a specific factor in regulating neuroblast mitotic activity during the development of alpha/beta neurons.
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Affiliation(s)
- J Kim
- Department of Molecular Biology, College of Life Sciences, Sejong University, 98 Kunja-dong, Kwangjin-ku, Seoul, 143-747, South Korea
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Aso Y, Grübel K, Busch S, Friedrich AB, Siwanowicz I, Tanimoto H. The mushroom body of adult Drosophila characterized by GAL4 drivers. J Neurogenet 2009; 23:156-72. [PMID: 19140035 DOI: 10.1080/01677060802471718] [Citation(s) in RCA: 269] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The mushroom body is required for a variety of behaviors of Drosophila melanogaster. Different types of intrinsic and extrinsic mushroom body neurons might underlie its functional diversity. There have been many GAL4 driver lines identified that prominently label the mushroom body intrinsic neurons, which are known as "Kenyon cells." Under one constant experimental condition, we analyzed and compared the the expression patterns of 25 GAL4 drivers labeling the mushroom body. As an internet resource, we established a digital catalog indexing representative confocal data of them. Further more, we counted the number of GAL4-positive Kenyon cells in each line. We found that approximately 2,000 Kenyon cells can be genetically labeled in total. Three major Kenyon cell subtypes, the gamma, alpha'/beta', and alpha/beta neurons, respectively, contribute to 33, 18, and 49% of 2,000 Kenyon cells. Taken together, this study lays groundwork for functional dissection of the mushroom body.
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Affiliation(s)
- Yoshinori Aso
- Max-Planck-Institut für Neurobiologie, Martinsried, Germany
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