1
|
Urban JM, Foulk MS, Bliss JE, Coleman CM, Lu N, Mazloom R, Brown SJ, Spradling AC, Gerbi SA. High contiguity de novo genome assembly and DNA modification analyses for the fungus fly, Sciara coprophila, using single-molecule sequencing. BMC Genomics 2021; 22:643. [PMID: 34488624 PMCID: PMC8419958 DOI: 10.1186/s12864-021-07926-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 08/08/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The lower Dipteran fungus fly, Sciara coprophila, has many unique biological features that challenge the rule of genome DNA constancy. For example, Sciara undergoes paternal chromosome elimination and maternal X chromosome nondisjunction during spermatogenesis, paternal X elimination during embryogenesis, intrachromosomal DNA amplification of DNA puff loci during larval development, and germline-limited chromosome elimination from all somatic cells. Paternal chromosome elimination in Sciara was the first observation of imprinting, though the mechanism remains a mystery. Here, we present the first draft genome sequence for Sciara coprophila to take a large step forward in addressing these features. RESULTS We assembled the Sciara genome using PacBio, Nanopore, and Illumina sequencing. To find an optimal assembly using these datasets, we generated 44 short-read and 50 long-read assemblies. We ranked assemblies using 27 metrics assessing contiguity, gene content, and dataset concordance. The highest-ranking assemblies were scaffolded using BioNano optical maps. RNA-seq datasets from multiple life stages and both sexes facilitated genome annotation. A set of 66 metrics was used to select the first draft assembly for Sciara. Nearly half of the Sciara genome sequence was anchored into chromosomes, and all scaffolds were classified as X-linked or autosomal by coverage. CONCLUSIONS We determined that X-linked genes in Sciara males undergo dosage compensation. An entire bacterial genome from the Rickettsia genus, a group known to be endosymbionts in insects, was co-assembled with the Sciara genome, opening the possibility that Rickettsia may function in sex determination in Sciara. Finally, the signal level of the PacBio and Nanopore data support the presence of cytosine and adenine modifications in the Sciara genome, consistent with a possible role in imprinting.
Collapse
Affiliation(s)
- John M Urban
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Sidney Frank Hall for Life Sciences, 185 Meeting Street, Providence, RI, 02912, USA.
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute Research Laboratories, 3520 San Martin Drive, Baltimore, MD, 21218, USA.
| | - Michael S Foulk
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Sidney Frank Hall for Life Sciences, 185 Meeting Street, Providence, RI, 02912, USA
- Present Address: Department of Biology, Mercyhurst University, Erie, PA, 16546, USA
| | - Jacob E Bliss
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Sidney Frank Hall for Life Sciences, 185 Meeting Street, Providence, RI, 02912, USA
| | - C Michelle Coleman
- KSU Bioinformatics Center, Kansas State University Division of Biology, Ackert Hall, Manhattan, Kansas, 66502, USA
| | - Nanyan Lu
- KSU Bioinformatics Center, Kansas State University Division of Biology, Ackert Hall, Manhattan, Kansas, 66502, USA
| | - Reza Mazloom
- KSU Bioinformatics Center, Kansas State University Division of Biology, Ackert Hall, Manhattan, Kansas, 66502, USA
| | - Susan J Brown
- KSU Bioinformatics Center, Kansas State University Division of Biology, Ackert Hall, Manhattan, Kansas, 66502, USA
| | - Allan C Spradling
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute Research Laboratories, 3520 San Martin Drive, Baltimore, MD, 21218, USA
| | - Susan A Gerbi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Sidney Frank Hall for Life Sciences, 185 Meeting Street, Providence, RI, 02912, USA.
| |
Collapse
|
2
|
Yamamoto Y, Gustafson EA, Foulk MS, Smith HS, Gerbi SA. Anatomy and evolution of a DNA replication origin. Chromosoma 2021; 130:199-214. [PMID: 34254172 DOI: 10.1007/s00412-021-00756-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/09/2021] [Accepted: 03/09/2021] [Indexed: 10/20/2022]
Abstract
DNA amplification occurs at the DNA puff II/9A locus in the fungus fly Sciara coprophila. As a foundation to study the molecular mechanism for the initiating events of II/9A DNA re-replication, we have sequenced 14 kb spanning a DNase hypersensitive site (DHS) upstream of the 1 kb amplification origin and through transcription units II/9-1 and II/9-2 downstream of the origin. These elements are annotated as well as the ORC binding site at the origin and the transition point (TP) between continuous and discontinuous DNA syntheses that marks the origin of bidirectional replication at the nucleotide level. A 9 bp motif found at the TP is repeated near the other end of the 1 kb ORI and may identify a putative second TP. The steroid hormone ecdysone induces DNA amplification as well as transcription and puffing at locus II/9A. Within the 14 kb, several matches to the ecdysone response element (EcRE) consensus sequence were identified, including some in the amplification origin region. EcRE O-P is at a central axis of a remarkable symmetry, equidistant to the TPs that are themselves equidistant to EcRE O-1 and EcRE O-2. DNA sequence alterations have occurred throughout the II/9A region in a newly discovered polymorphism (#2). Polymorphism #2 is not specific to developmental stage, sex, or tissue, and it does not impair DNA amplification. The DHS, both 9 bp TP sequences, and EcREs O-1, O-P, and O-2 are conserved between the polymorphism #1 and #2 sequences, suggesting their functional importance and retention during evolutionary selection. Moreover, a 72 bp sequence in the Sciara DHS at DNA puff II/9A is conserved in DNA puff C-3 of Rhynchosciara americana. Comparisons are discussed between the Sciara II/9A amplicon and the chorion locus amplicon on the third chromosome of Drosophila.
Collapse
Affiliation(s)
- Yutaka Yamamoto
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Box G - Sidney Frank Life Sciences Building room 260, Providence, RI, 02912, USA
| | - Eric A Gustafson
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Box G - Sidney Frank Life Sciences Building room 260, Providence, RI, 02912, USA.,Zipher Medical Affairs Co., 380 Wareham Street, Marion, MA, 02738, USA
| | - Michael S Foulk
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Box G - Sidney Frank Life Sciences Building room 260, Providence, RI, 02912, USA.,Department of Biology, Mercyhurst University, 501 East 38th Street, Erie, PA, 16546, USA
| | - Heidi S Smith
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Box G - Sidney Frank Life Sciences Building room 260, Providence, RI, 02912, USA
| | - Susan A Gerbi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University Division of Biology and Medicine, Box G - Sidney Frank Life Sciences Building room 260, Providence, RI, 02912, USA.
| |
Collapse
|
3
|
Simon CR, Siviero F, Monesi N. Beyond DNA puffs: What can we learn from studying sciarids? Genesis 2016; 54:361-78. [PMID: 27178805 DOI: 10.1002/dvg.22946] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 11/07/2022]
Abstract
Members of the Sciaridae family attracted the interest of researchers because of the demonstration that the DNA puff regions, which are formed in the salivary gland polytene chromosomes at the end of the fourth larval instar, constitute sites of developmentally regulated gene amplification. Besides contributing to a deeper understanding of the process of gene amplification, the study of sciarids has also provided important insights on other biological processes such as sex determination, programmed cell death, insect immunity, telomere maintenance, and nucleolar organizing regions (NOR) formation. Open questions in sciarids include among others, early development, the role of noncoding RNAs in gene amplification and the relationship between gene amplification and transcription in DNA puff forming regions. These and other questions can now be pursued with next generation sequencing techniques and experiments using RNAi experiments, since this latter technique has been shown to be feasible in sciarids. These new perspectives in the field of sciarid biology open the opportunity to consolidate sciarid species as important emerging models. genesis 54:361-378, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Claudio Roberto Simon
- Departamento de Biologia Estrutural, Universidade Federal do Triângulo Mineiro-UFTM, Instituto de Ciências Biológicas e Naturais, Uberaba, MG, Brazil, CEP 38025-015
| | - Fábio Siviero
- Departamento de Biologia Celular e do Desenvolvimento, Universidade de São Paulo, Instituto de Ciências Biomédicas, São Paulo, SP, Brazil, CEP 05508-900
| | - Nadia Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Universidade de São Paulo, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| |
Collapse
|
4
|
Björk P, Wieslander L. The Balbiani Ring Story: Synthesis, Assembly, Processing, and Transport of Specific Messenger RNA-Protein Complexes. Annu Rev Biochem 2015; 84:65-92. [PMID: 26034888 DOI: 10.1146/annurev-biochem-060614-034150] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eukaryotic gene expression is the result of the integrated action of multimolecular machineries. These machineries associate with gene transcripts, often already nascent precursor messenger RNAs (pre-mRNAs). They rebuild the transcript and convey properties allowing the processed transcript, the mRNA, to be exported to the cytoplasm, quality controlled, stored, translated, and degraded. To understand these integrated processes, one must understand the temporal and spatial aspects of the fate of the gene transcripts in relation to interacting molecular machineries. Improved methodology is necessary to study gene expression in vivo for endogenous genes. A complementary approach is to study biological systems that provide exceptional experimental possibilities. We describe such a system, the Balbiani ring (BR) genes in polytene cells in the dipteran Chironomus tentans. The BR genes, along with their pre-mRNA-protein complexes (pre-mRNPs) and mRNA-protein complexes (mRNPs), allow the visualization of intact cell nuclei and enable analyses of where and when different molecular machineries associate with and act on the BR pre-mRNAs and mRNAs.
Collapse
Affiliation(s)
- Petra Björk
- Department of Molecular Biosciences, Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden;
| | | |
Collapse
|
5
|
Abstract
Polyploid cells, which contain more than two genome copies, occur throughout nature. Beyond well-established roles in increasing cell size/metabolic output, polyploidy can also promote nonuniform genome, transcriptome, and metabolome alterations. Polyploidy also frequently confers resistance to environmental stresses not tolerated by diploid cells. Recent progress has begun to unravel how this fascinating phenomenon contributes to normal physiology and disease.
Collapse
Affiliation(s)
- Kevin P Schoenfelder
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Donald T Fox
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| |
Collapse
|
6
|
The ecdysone receptor (ScEcR-A) binds DNA puffs at the start of DNA amplification in Sciara coprophila. Chromosome Res 2013; 21:345-60. [PMID: 23737076 DOI: 10.1007/s10577-013-9360-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 04/11/2013] [Accepted: 04/23/2013] [Indexed: 12/20/2022]
Abstract
The steroid hormone ecdysone induces DNA amplification and subsequent DNA puff formation in late fourth larval instar salivary gland polytene chromosomes of the fungus fly, Sciara coprophila. Previous in vitro studies on DNA puff II/9A in Sciara demonstrated that the ecdysone receptor (ScEcR-A) efficiently binds an ecdysone response element adjacent to the origin recognition complex binding site within the II/9A amplification origin, implying a role for ScEcR-A in amplification. Here, we extrapolate the molecular details from locus II/9A to the rest of the genome using immunofluorescence with a ScEcR-A-specific antibody. ScEcR-A binds all DNA puff sites just as amplification begins and persists throughout the processes of amplification, transcription, and puffing. Ecdysone injections into pre-amplification stage larvae prematurely induce both DNA amplification and ScEcR-A binding to DNA puff sites. These data are consistent with a direct role for ScEcR-A in DNA amplification.
Collapse
|
7
|
Foulk MS, Waggener JM, Johnson JM, Yamamoto Y, Liew GM, Urnov FD, Young Y, Lee G, Smith HS, Gerbi SA. Isolation and characterization of the ecdysone receptor and its heterodimeric partner ultraspiracle through development in Sciara coprophila. Chromosoma 2013; 122:103-19. [PMID: 23321980 DOI: 10.1007/s00412-012-0395-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/09/2012] [Accepted: 12/18/2012] [Indexed: 01/08/2023]
Abstract
Regulation of DNA replication is critical, and loss of control can lead to DNA amplification. Naturally occurring, developmentally regulated DNA amplification occurs in the DNA puffs of the late larval salivary gland giant polytene chromosomes in the fungus fly, Sciara coprophila. The steroid hormone ecdysone induces DNA amplification in Sciara, and the amplification origin of DNA puff II/9A contains a putative binding site for the ecdysone receptor (EcR). We report here the isolation, cloning, and characterizing of two ecdysone receptor isoforms in Sciara (ScEcR-A and ScEcR-B) and the heterodimeric partner, ultraspiracle (ScUSP). ScEcR-A is the predominant isoform in larval tissues and ScEcR-B in adult tissues, contrary to the pattern in Drosophila. Moreover, ScEcR-A is produced at amplification but is absent just prior. We discuss these results in relation to the model of ecdysone regulation of DNA amplification.
Collapse
Affiliation(s)
- Michael S Foulk
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, 02912, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Nordman J, Li S, Eng T, MacAlpine D, Orr-Weaver TL. Developmental control of the DNA replication and transcription programs. Genome Res 2011; 21:175-81. [PMID: 21177957 PMCID: PMC3032921 DOI: 10.1101/gr.114611.110] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/26/2010] [Indexed: 01/03/2023]
Abstract
Polyploid or polytene cells, which have more than 2C DNA content, are widespread throughout nature and present in most differentiated Drosophila tissues. These cells also can display differential replication, that is, genomic regions of increased or decreased DNA copy number relative to overall genomic ploidy. How frequently differential replication is used as a developmental strategy remains unclear. Here, we use genome-wide array-based comparative genomic hybridization (aCGH) to profile differential DNA replication in isolated and purified larval fat body and midgut tissues of Drosophila, and we compare them with recent aCGH profiles of the larval salivary gland. We identify sites of euchromatic underreplication that are common to all three tissues and others that are tissue specific. We demonstrate that both common and tissue-specific underreplicated sites are dependent on the Suppressor of Underreplication protein, SUUR. mRNA-seq profiling shows that whereas underreplicated regions are generally transcriptionally silent in the larval midgut and salivary gland, transcriptional silencing and underreplication have been uncoupled in the larval fat body. In addition to revealing the prevalence of differential replication, our results show that transcriptional silencing and underreplication can be mechanistically uncoupled.
Collapse
Affiliation(s)
- Jared Nordman
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Sharon Li
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Thomas Eng
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - David MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Terry L. Orr-Weaver
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
9
|
Candido-Silva J, Monesi N. Bradysia hygida (Diptera, Sciaridae) presents two eukaryotic Elongation Factor 1A gene homologues: partial characterization of the eukaryotic Elongation Factor 1A-F1 gene. Braz J Med Biol Res 2010; 43:437-44. [DOI: 10.1590/s0100-879x2010007500029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 04/01/2010] [Indexed: 11/22/2022] Open
|
10
|
Candido-Silva JA, de Carvalho DP, Coelho GR, de Almeida JC. Indirect immune detection of ecdysone receptor (EcR) during the formation of DNA puffs in Bradysia hygida (Diptera, Sciaridae). Chromosome Res 2008; 16:609-22. [PMID: 18483872 DOI: 10.1007/s10577-008-1215-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 02/18/2008] [Accepted: 02/18/2008] [Indexed: 11/24/2022]
Abstract
Gene amplification occurs in Bradysia hygida salivary glands, at the end of the fourth larval instar. The hormone 20-hydroxyecdysone (20E) triggers this process, which results in DNA puff formation. Amplified genes are activated in two distinct groups. The activity of the first group is dependent on high levels of 20E, while the second group needs low hormone levels. Consequently, the salivary glands of B. hygida constitute an interesting biological model to study how 20E, and its receptors, affect gene amplification and activity. We produced polyclonal antibodies against B. hygida EcR (BhEcR). In western blots a polypeptide of about 66 kDa was detected in salivary gland extracts. The antibodies were also used for indirect immune-localization of BhEcR in polytene chromosomes. RNA-polymerase II was also immune-detected. We did not detect the receptor in chromosome C where the first and second groups of DNA puffs form during DNA puff anlage formation, but it was present during puff expansion. During the active phase of both groups of DNA puffs, RNA polymerase II co-localized with BhEcR. After puff regression, these antigens were not detected. Apparently, EcR plays a direct role in the transcription of amplified genes, but its role in gene amplification remains enigmatic.
Collapse
Affiliation(s)
- Juliana Aparecida Candido-Silva
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Universidade de São Paulo, Ribeirão Preto, SP, CEP 14049-900, Brazil
| | | | | | | |
Collapse
|
11
|
Andrioli LP, Gorab E, Amabis JM. The DNA puff 4C expresses a salivary secretion protein in Trichosia pubescens (Diptera; Sciaridae). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2008; 67:76-86. [PMID: 18076109 DOI: 10.1002/arch.20222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
DNA puffs are genomic regions of polytene chromosomes that undergo developmentally controlled DNA amplification and transcription in salivary glands of sciarid flies. Here, we tested the hypothesis that DNA puff genes code for salivary proteins in Trichosia pubescens. To do that, we generated antibodies against saliva and immunoscreened a cDNA library made from salivary glands. We isolated clones corresponding to DNA puff regions, including clone D-50 that contained the entire coding sequence of the previously isolated C4B1 gene from puff 4C. Indeed, we showed that puff 4C is a DNA puff region detecting its local transcription and its extra rounds of DNA incorporation compared to neighboring regions. We further confirmed D-50 clone identity in Western blots reacted with the anti-saliva anitiserum. We detected a recombinant protein expressed by this clone that had the expected size for a full-length product of the gene. We end with a discussion of the relationship between DNA puff genes and their products.
Collapse
Affiliation(s)
- Luiz Paulo Andrioli
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
| | | | | |
Collapse
|
12
|
Lecci MS, Malta TM, Flausino VT, Gitaí DL, Ruiz JC, Monesi N. Functional and bioinformatics analyses reveal conservation ofcis-regulatory elements between sciaridae and drosophilidae. Genesis 2008; 46:43-51. [DOI: 10.1002/dvg.20364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
13
|
Affiliation(s)
- Susan A Gerbi
- Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912, USA.
| |
Collapse
|
14
|
Foulk MS, Liang C, Wu N, Blitzblau HG, Smith H, Alam D, Batra M, Gerbi SA. Ecdysone induces transcription and amplification in Sciara coprophila DNA puff II/9A. Dev Biol 2006; 299:151-63. [PMID: 16938289 DOI: 10.1016/j.ydbio.2006.07.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 07/13/2006] [Accepted: 07/14/2006] [Indexed: 01/10/2023]
Abstract
DNA replication is normally tightly regulated to ensure the production of only one copy of the genome per cell cycle. However, DNA puffs of the salivary gland giant polytene chromosomes of Sciara coprophila undergo DNA amplification during the normal course of development, overriding this control. This developmental strategy provides more template for the production of large amounts of protein needed for pupation. We have focused on DNA puff II/9A, which amplifies approximately 17-fold over the rest of the genome. Evidence presented here suggests that DNA amplification at this locus is controlled by the steroid hormone ecdysone, the master regulator of insect development. Explanted, pre-amplification stage salivary glands undergo premature amplification when incubated with ecdysone. Injection of ecdysone into pre-amplification stage larvae induces amplification. Ecdysone also induces transcription of the II/9A genes. We report the presence of a putative ecdysone response element directly adjacent to the origin recognition complex (ORC)-binding site in the II/9A origin and demonstrate that it is efficiently bound by the Sciara ecdysone receptor. These results implicate ecdysone in the regulation of DNA amplification in Sciara and suggest the ecdysone receptor may be the elusive amplification factor. This would be a new role for this transcription factor.
Collapse
Affiliation(s)
- Michael S Foulk
- Brown University, 69 Brown St.-J.W. Wilson Laboratory, Providence, RI 02912, USA
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Monesi N, Silva JA, Martins PCM, Teixeira AB, Dornelas EC, Moreira JE, Paçó Larson ML. Immunocharacterization of the DNA puff BhC4-1 protein of Bradysia hygida (Diptera: Sciaridae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:531-542. [PMID: 15147755 DOI: 10.1016/j.ibmb.2004.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2003] [Accepted: 02/13/2004] [Indexed: 05/24/2023]
Abstract
The DNA puff BhC4-1 gene is amplified and highly expressed in the salivary gland of Bradysia hygida late larvae. Using affinity-purified polyclonal antibodies we have identified the product of the BhC4-1 gene as a 43 kDa polypeptide which is present in extracts of salivary glands from late fourth instar larvae and in the corresponding gland secretion, but not in glands from earlier stages. We also demonstrate that this protein is produced mainly in the S1 and S3 regions of the salivary gland, where BhC4-1 amplification levels are more pronounced and larger amounts of mRNA are produced. By immunoelectron microscopy the BhC4-1 protein was detected in secretory granules of the S1 and S3 regions, and localized in fibrous structures present in the saliva.
Collapse
Affiliation(s)
- N Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | | | | | | | | |
Collapse
|
16
|
Claycomb JM, Benasutti M, Bosco G, Fenger DD, Orr-Weaver TL. Gene amplification as a developmental strategy: isolation of two developmental amplicons in Drosophila. Dev Cell 2004; 6:145-55. [PMID: 14723854 DOI: 10.1016/s1534-5807(03)00398-8] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Gene amplification is known to be critical for upregulating gene expression in a few cases, but the extent to which amplification is utilized in the development of diverse organisms remains unknown. By quantifying genomic DNA hybridization to microarrays to assay gene copy number, we identified two additional developmental amplicons in the follicle cells of the Drosophila ovary. Both amplicons contain genes which, following their amplification, are expressed in the follicle cells, and the expression of three of these genes becomes restricted to specialized follicle cells late in differentiation. Genetic analysis establishes that at least one of these genes, yellow-g, is critical for follicle cell function, because mutations in yellow-g disrupt eggshell integrity. Thus, during follicle cell differentiation the entire genome is overreplicated as the cells become polyploid, and subsequently specific genomic intervals are overreplicated to facilitate gene expression.
Collapse
Affiliation(s)
- Julie M Claycomb
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | | | | | | | | |
Collapse
|
17
|
Monesi N, Basso LR, Paçó-Larson ML. Identification of regulatory regions in the DNA puff BhC4-1 promoter. INSECT MOLECULAR BIOLOGY 2003; 12:247-254. [PMID: 12752658 DOI: 10.1046/j.1365-2583.2003.00408.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The mechanisms that control DNA puff BhC4-1 expression in the salivary gland of sciarid late larvae have been shown to be conserved in Drosophila. By analysing Drosophila transformed with constructs carrying progressive deletions of the BhC4-1 promoter fragment (-3314/+40) fused to the lacZ reporter gene we show that the elements required for the correct BhC4-1-lacZ developmental regulation in prepupal salivary glands are contained in a 226 bp fragment (-186/+40). Also, interestingly, this study identified a 67 bp fragment (-253/-187) that activates BhC4-1-lacZ expression specifically in the ring gland.
Collapse
Affiliation(s)
- N Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil.
| | | | | |
Collapse
|
18
|
Lunyak VV, Ezrokhi M, Smith HS, Gerbi SA. Developmental changes in the Sciara II/9A initiation zone for DNA replication. Mol Cell Biol 2002; 22:8426-37. [PMID: 12446763 PMCID: PMC139883 DOI: 10.1128/mcb.22.24.8426-8437.2002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Developmentally regulated initiation of DNA synthesis was studied in the fly Sciara at locus II/9A. PCR analysis of nascent strands revealed an initiation zone that spans approximately 8 kb in mitotic embryonic cells and endoreplicating salivary glands but contracts to 1.2 to 2.0 kb during DNA amplification of DNA puff II/9A. Thus, the amplification origin occurs within the initiation zone used for normal replication. The initiation zone left-hand border is constant, but the right-hand border changes during development. Also, there is a shift in the preferred site for initiation of DNA synthesis during DNA amplification compared to that in preamplification stages. This is the first demonstration that once an initiation zone is defined in embryos, its borders and preferred replication start sites can change during development. Chromatin immunoprecipitation showed that the RNA polymerase II 140-kDa subunit occupies the promoter of gene II/9-1 during DNA amplification, even though intense transcription will not start until the next developmental stage. RNA polymerase II is adjacent to the right-hand border of the initiation zone at DNA amplification but not at preamplification, suggesting that it may influence the position of this border. These findings support a relationship between the transcriptional machinery and establishment of the replication initiation zone.
Collapse
Affiliation(s)
- Victoria V Lunyak
- Brown University Division of Biology and Medicine, Providence, Rhode Island 02912, USA
| | | | | | | |
Collapse
|
19
|
Monesi N, Sousa JF, Paçó-Larson ML. The DNA puff BhB10-1 gene is differentially expressed in various tissues of Bradysia hygida late larvae and constitutively transcribed in transgenic Drosophila. Braz J Med Biol Res 2001; 34:851-9. [PMID: 11449302 DOI: 10.1590/s0100-879x2001000700003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We extended the characterization of the DNA puff BhB10-1 gene of Bradysia hygida by showing that, although its mRNA is detected only at the end of the fourth larval instar, BhB10-1 expression is not restricted to the salivary gland, the tissue in which this gene is amplified. Different amounts of BhB10-1 mRNA were detected in other larval tissues such as gut, Malpighian tubules, fat body, brain and cuticle, suggesting that this gene is expressed differentially in the various tissues analyzed. Analysis of transgenic Drosophila carrying the BhB10-1 transcription unit and flanking sequences revealed that the tested fragment promotes transcription in a constitutive manner. We suggest that either cis-regulatory elements are missing in the transgene or factors that temporally regulate the BhB10-1 gene in B. hygida are not conserved in Drosophila.
Collapse
Affiliation(s)
- N Monesi
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
| | | | | |
Collapse
|
20
|
Fiorini A, Basso LR, Paçó-Larson ML, Fernandez MA. Mapping of intrinsic bent DNA sites in the upstream region of DNA puff BhC4-1 amplified gene. J Cell Biochem 2001; 83:1-13. [PMID: 11500949 DOI: 10.1002/jcb.1188] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We have identified bent DNA sites in the distal and proximal DNA puff BhC4-1 amplified gene promoter region of Bradysia hygida. The 2D modeling of the 3D DNA path and the ENDS ratio values calculated in this promoter region resulted in the identification of ten pronounced bent sites named BhC4B - 9 to + 1. The 1847 bp fragment (- 3697 to - 1850) in relation to the transcription start site shows multiple bending sites, BhC4B - 9 to BhC4B - 4, with periodicity approximately 300 bp. The analysis of the other identified bent region, starting at position - 957, reveals that the BhC4B + 1 bent site colocalizes with the putative BhC4-1 minimal promoter. The sequence analysis of bent site BhC4B - 4 shows a distribution of dA*dT at approximately 10 bp intervals between the middle of each tract, but intervals with more than one turn, approximately 20 bp, two helix turns, were detected in the other bent sites described here. The bent sites BhC4B - 6 and BhC4B - 4, contain two consensus sequences, with 60 bp each. The apparent molecular weight of fragments in the BhC4-1 promoter region were estimated in agarose gels and compared with the data obtained in polyacrylamide gels without and with ethidium bromide. The mobility reduction ratios (R-values) were determined, and a high R-value, 1.80, for a 1215 bp fragment in the distal promoter region and a 1.23 significant R-value for a 662 bp fragment in the proximal segment were found. To further analyze the predicted bent DNA sites in these fragments, the 2D trajectories of the 3D DNA path and other parameters, AT percentage, roll angle, ENDS ratio and DeltaG, were determined. The role of these bent sites in the BhC4-1 transcription regulation is discussed.
Collapse
Affiliation(s)
- A Fiorini
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, Paraná 87020-900, Brazil
| | | | | | | |
Collapse
|
21
|
de Carvalho DP, Coelho PS, de Almeida JC. A dual role of 20-hydroxyecdysone in the control of protein synthesis related to DNA puff activity in the anterior region of Bradysia hygida (Diptera, Sciaridae) salivary gland. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2000; 30:541-548. [PMID: 10844246 DOI: 10.1016/s0965-1748(00)00022-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
During the last 30 h of the larval stage, the salivary glands of Bradysia hygida show the amplification of some genes, resulting in the formation of two successive groups of DNA puffs, which direct the synthesis of two different sets of polypeptides. Incubation of anterior (S1) salivary gland regions, at age E7, beginning of first group of DNA puffs activity, in culture medium for 2 to 10 h results in a decrease in the synthesis of the polypeptides characteristic of this period. However, during subsequent incubation (from E7 to E7+12 h-24 h), when the second group of DNA puffs is active, S1 regions were able to synthesize some polypeptides characteristic of this period. The role of 20-OH ecdysone was studied, in vitro and in vivo, during these two periods of protein synthesis in S1 regions. The presence of the hormone was shown to be necessary to maintain, in vitro, the synthesis of the first set of polypeptides and was strongly inhibitory, in vitro and in vivo, to the synthesis of the second set of polypeptides. Thus, it is likely that the activity of the two distinct groups of DNA puffs is under opposite 20-OH-ecdysone control mechanisms.
Collapse
Affiliation(s)
- D P de Carvalho
- Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900, SP, Ribeirão Preto, Brazil
| | | | | |
Collapse
|
22
|
Fontes AM, Conacci ME, Monesi N, de Almeida JC, Paçó-Larson ML. The DNA puff BhB10-1 gene encodes a glycine-rich protein secreted by the late stage larval salivary glands of Bradysia hygida. Gene X 1999; 231:67-75. [PMID: 10231570 DOI: 10.1016/s0378-1119(99)00089-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
We present the molecular characterization of a gene of Bradysia hygida DNA puff B10 whose temporal expression in the salivary gland correlates with the puff expansion. The transcription unit of this gene, named BhB10-1, was mapped in a 2-kb EcoRI genomic fragment that is amplified in the salivary gland of late fourth instar larvae. Its 1.3-kb transcript undergoes poly-A tail shortening during development, indicating that post-transcriptional controls as well as transcription activation are involved in the temporal regulation of the BhB10-1 gene. Analysis of the deduced amino acid sequence from the cDNA indicates that the BhB10-1 protein is a glycine-rich secretory protein. A BhB10-1-fusion protein expressed in bacteria was used to raise polyclonal antibodies. Using an immunopurified antibody, we identified the product of the DNA puff BhB10-1 gene as a 23-kDa polypeptide that is produced mainly by the salivary gland regions S1 and S3 and is present in the saliva of late larvae. This is the first direct identification of a protein encoded by a DNA puff amplified gene.
Collapse
Affiliation(s)
- A M Fontes
- Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, CEP 14049-900, Ribeirão Preto, Brazil
| | | | | | | | | |
Collapse
|
23
|
de-Almeida JC. A 28-fold increase in secretory protein synthesis is associated with DNA puff activity in the salivary gland of Bradysia hygida (Diptera, Sciaridae). Braz J Med Biol Res 1997; 30:605-14. [PMID: 9283627 DOI: 10.1590/s0100-879x1997000500006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
When the first group of DNA puffs is active in the salivary gland regions S1 and S3 of Bradysia hygida larvae, there is a large increase in the production and secretion of new salivary proteins demonstrable by [3H]-Leu incorporation. The present study shows that protein separation by SDS-PAGE and detection by fluorography demonstrated that these polypeptides range in molecular mass from about 23 to 100 kDa. Furthermore, these proteins were synthesized mainly in the S1 and S3 salivary gland regions where the DNA puffs C7, C5, C4 and B10 are conspicuous, while in the S2 region protein synthesis was very low. Others have shown that the extent of amplification for DNA sequences that code for mRNA in the DNA puffs C4 and B10 was about 22 and 10 times, respectively. The present data for this group of DNA puffs are consistent with the proposition that gene amplification is necessary to provide some cells with additional gene copies for the production of massive amounts of proteins within a short period of time.
Collapse
Affiliation(s)
- J C de-Almeida
- Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil
| |
Collapse
|
24
|
|
25
|
Monesi N, Fernandez MA, Fontes AM, Basso LR, Nakanishi Y, Baron B, Buttin G, Paçó-Larson ML. Molecular characterization of an 18 kb segment of DNA puff C4 of Bradysia hygida (Diptera, sciaridae). Chromosoma 1995; 103:715-24. [PMID: 7664619 DOI: 10.1007/bf00344233] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The data presented here are an extension of the molecular characterization of DNA puff C4 of Bradysia hygida. A cDNA related to a gene amplified in this puff and expressed when puff C4 expands was cloned and sequenced. Analysis of the amino acid sequence deduced from the open reading frame present in the cDNA indicate that the encoded protein is secreted and comprises mostly alpha-helical coiled-coil. An 18 kb genomic segment containing the transcription unit of this gene was also cloned and the structure and expression of the 1.4 kb mRNA was determined. Quantitative slot blot hybridization of DNA complementary to the transcription unit shows that this gene is amplified about 21 times in the salivary gland, confirming data previously obtained. Fragments upstream of the 5' end, and beyond the 3' end, of the gene transcription unit were also analysed and shown to be amplified at least eight and five times, respectively. Based on these data we discuss how amplification could occur at DNA puffs.
Collapse
Affiliation(s)
- N Monesi
- Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14049-900, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Analysis of an origin of DNA amplification in Sciara coprophila by a novel three-dimensional gel method. Mol Cell Biol 1994. [PMID: 8289825 DOI: 10.1128/mcb.14.2.1520] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The replication origin region for DNA amplification in Sciara coprophila DNA puff II/9A was analyzed with a novel three-dimensional (3D) gel method. Our 3D gel method involves running a neutral/neutral 2D gel and then cutting out vertical gel slices from the area containing replication intermediates, rotating these slices 90 degrees to form the third dimension, and running an alkaline gel for each of the slices. Therefore, replication intermediates are separated into forks and bubbles and then are resolved into parental and nascent strands. We used this technique to determine the size of forks and bubbles and to confirm the location of the major initiation region previously mapped by 2D gels to a 1-kb region. Furthermore, our 3D gel analyses suggest that only one initiation event in the origin region occurs on a single DNA molecule and that the fork arc in the composite fork-plus-bubble pattern in neutral/neutral 2D gels does not result from broken bubbles.
Collapse
|
27
|
Liang C, Gerbi SA. Analysis of an origin of DNA amplification in Sciara coprophila by a novel three-dimensional gel method. Mol Cell Biol 1994; 14:1520-9. [PMID: 8289825 PMCID: PMC358507 DOI: 10.1128/mcb.14.2.1520-1529.1994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The replication origin region for DNA amplification in Sciara coprophila DNA puff II/9A was analyzed with a novel three-dimensional (3D) gel method. Our 3D gel method involves running a neutral/neutral 2D gel and then cutting out vertical gel slices from the area containing replication intermediates, rotating these slices 90 degrees to form the third dimension, and running an alkaline gel for each of the slices. Therefore, replication intermediates are separated into forks and bubbles and then are resolved into parental and nascent strands. We used this technique to determine the size of forks and bubbles and to confirm the location of the major initiation region previously mapped by 2D gels to a 1-kb region. Furthermore, our 3D gel analyses suggest that only one initiation event in the origin region occurs on a single DNA molecule and that the fork arc in the composite fork-plus-bubble pattern in neutral/neutral 2D gels does not result from broken bubbles.
Collapse
Affiliation(s)
- C Liang
- Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912
| | | |
Collapse
|
28
|
Liang C, Spitzer JD, Smith HS, Gerbi SA. Replication initiates at a confined region during DNA amplification in Sciara DNA puff II/9A. Genes Dev 1993; 7:1072-84. [PMID: 8504930 DOI: 10.1101/gad.7.6.1072] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Two independent two-dimensional (2D) gel methods were used to map an origin of replication that is developmentally regulated by the steroid hormone ecdysone, namely an origin for DNA puff amplification in the fungus fly Sciara coprophila. Initiation of replication was found to occur within a small region of no larger than 6 kb by use of the neutral/neutral 2D gel method. Neutral/alkaline 2D gel analyses support the results of the neutral/neutral 2D gels and further define within the origin region an approximately 1-kb area where the majority of replication initiates. This is the first example of an origin of replication in multicellular eukaryotes that has been mapped by 2D gels to such a small defined region. Moreover, replication can be seen by the neutral/alkaline 2D gel method to proceed bidirectionally outward from this replication origin region. These data are consistent with an onion-skin mechanism whereby multiple rounds of DNA replication initiate at a specific origin of replication for Sciara DNA puff amplification.
Collapse
Affiliation(s)
- C Liang
- Division of Biology and Medicine, Brown University, Providence, Rhode Island 02912
| | | | | | | |
Collapse
|