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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.
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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.
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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.
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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.
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Structure and function of the alternatively spliced isoforms of the ecdysone receptor gene in the Chinese mitten crab, Eriocheir sinensis. Sci Rep 2017; 7:12993. [PMID: 29021633 PMCID: PMC5636884 DOI: 10.1038/s41598-017-13474-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 09/26/2017] [Indexed: 11/10/2022] Open
Abstract
Alternative splicing is an essential molecular mechanism that increase the protein diversity of a species to regulate important biological processes. Ecdysone receptor (EcR), an essential nuclear receptor, is essential in the molting, growth, development, reproduction, and regeneration of crustaceans. In this study, the whole sequence of EcR gene from Eriocheir sinensis was obtained. The sequence was 45,481 bp in length with 9 exons. Moreover, four alternatively spliced EcR isoforms (Es-EcR-1, Es-EcR-2, Es-EcR-3 and Es-EcR-4) were identified. The four isoforms harbored a common A/B domain and a DNA-binding region but different D domains and ligand-binding regions. Three alternative splicing patterns (alternative 5′ splice site, exon skipping, and intron retention) were identified in the four isoforms. Functional studies indicated that the four isoforms have specific functions. Es-EcR-3 may play essential roles in regulating periodic molting. Es-EcR-2 may participate in the regulation of ovarian development. Our results indicated that Es-EcR has broad regulatory functions in molting and development and established the molecular basis for the investigation of ecdysteroid signaling related pathways in E. sinensis.
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Frank HO, Sanchez DG, de Freitas Oliveira L, Kobarg J, Monesi N. The Drosophila melanogaster Eip74EF-PA transcription factor directly binds the sciarid BhC4-1 promoter. Genesis 2017; 55. [PMID: 28971561 DOI: 10.1002/dvg.23075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 12/28/2022]
Abstract
The DNA puff BhC4-1 gene of Bradysia hygida (Diptera, Sciaridae) is amplified and expressed in the salivary glands at the end of the last larval instar. Even though there are no BhC4-1 orthologs in Drosophila melanogaster, the mechanisms that regulate BhC4-1 gene expression in B. hygida are for the most part conserved in D. melanogaster. The BhC4-1 promoter contains a 129bp (-186/-58) cis-regulatory module (CRM) that drives developmentally regulated expression in transgenic salivary glands at the onset of metamorphosis. Both in the sciarid and in transgenic D. melanogaster, BhC4-1 gene expression is induced by the increase in ecdysone titers that triggers metamorphosis. Genetic interaction experiments revealed that in the absence of the Eip74EF-PA early gene isoform BhC4-1-lacZ levels of expression in the salivary gland are severely reduced. Here we show that the overexpression of the Eip74EF-PA transcription factor is sufficient to anticipate BhC4-1-lacZ expression in transgenic D. melanogaster. Through yeast one-hybrid assays we confirm that the Eip74EF-PA transcription factor directly binds to the 129 bp sciarid CRM. Together, these results contribute to the characterization of an insect CRM and indicate that the ecdysone gene regulatory network that promotes metamorphosis is conserved between D. melanogaster and the sciarid B. hygida.
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Affiliation(s)
- Henrique Oliveira Frank
- Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Danilo Garcia Sanchez
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, sem número, Ribeirão Preto, São Paulo, 14040-903, Brazil
| | - Lucas de Freitas Oliveira
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, sem número, Ribeirão Preto, São Paulo, 14040-903, Brazil
| | - Jörg Kobarg
- Faculdade de Ciências Farmacêuticas e Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade Estadual de Campinas, Rua Monteiro Lobato 255, Campinas, São Paulo, 13083-970, Brazil
| | - Nadia Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, sem número, Ribeirão Preto, São Paulo, 14040-903, Brazil
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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: 7] [Impact Index Per Article: 0.9] [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.
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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
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Abstract
The mechanism that duplicates the nuclear genome during the trillions of cell divisions required to develop from zygote to adult is the same throughout the eukarya, but the mechanisms that determine where, when and how much nuclear genome duplication occur regulate development and differ among the eukarya. They allow organisms to change the rate of cell proliferation during development, to activate zygotic gene expression independently of DNA replication, and to restrict nuclear DNA replication to once per cell division. They allow specialized cells to exit their mitotic cell cycle and differentiate into polyploid cells, and in some cases, to amplify the number of copies of specific genes. It is genome duplication that drives evolution, by virtue of the errors that inevitably occur when the same process is repeated trillions of times. It is, unfortunately, the same errors that produce age-related genetic disorders such as cancer.
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Affiliation(s)
- Melvin L DePamphilis
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
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Developmental ecdysteroid titers and DNA puffs in larvae of two sciarid species, Rhynchosciara americana and Rhynchosciara milleri (Diptera: Sciaridae). Genetica 2015; 143:597-612. [DOI: 10.1007/s10709-015-9859-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/01/2015] [Indexed: 01/16/2023]
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Candido-Silva JA, Machado MCR, Hartfelder KH, de Almeida JC, Paçó-Larson ML, Monesi N. Amplification and expression of a salivary gland DNA puff gene in the prothoracic gland of Bradysia hygida (Diptera: Sciaridae). JOURNAL OF INSECT PHYSIOLOGY 2015; 74:30-37. [PMID: 25666977 DOI: 10.1016/j.jinsphys.2015.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 01/29/2015] [Accepted: 01/30/2015] [Indexed: 06/04/2023]
Abstract
The DNA puff BhC4-1 gene, located in DNA puff C4 of Bradysiahygida, is amplified and expressed in the salivary gland at the end of the fourth larval instar as a late response to the increase in 20-hydroxyecdysone titer that triggers metamorphosis. Functional studies revealed that the mechanisms that regulate BhC4-1 expression in the salivary gland are conserved in transgenic Drosophila. These studies also led to the identification of a cis-regulatory module that drives developmentally regulated expression of BhC4-1-lacZ in the prothoracic gland cells of the ring gland, a compound organ which in Drosophila results from the fusion of the prothoracic glands, the corpus allatum and the corpus cardiacum. Here we have investigated the occurrence of BhC4-1 expression in B. hygida prothoracic glands. We report the identification of the B. hygida prothoracic gland and demonstrate that it releases ecdysone. Using RT-qPCR, western blots and immunolocalization experiments, we demonstrate that the BhC4-1 mRNA and the BhC4-1 protein are both expressed in the B. hygida prothoracic glands at the same time that DNA puff C4 is formed in the salivary gland. We also show that BhC4-1 is concomitantly amplified 4.8-fold in the prothoracic gland and 23-fold in the salivary gland. Our results reveal the occurrence of stage specific expression of a DNA puff gene in the prothoracic glands of B. hygida, and extend previous studies that have shown that DNA puff genes expression is not restricted to the salivary gland. In addition, the description of stage specific gene amplification in the prothoracic glands of B. hygida constitutes the first demonstration that gene amplification in Diptera might occur concomitantly in two different tissues in the same developmental stage.
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Affiliation(s)
- Juliana Aparecida Candido-Silva
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14040-903, Brazil.
| | - Maiaro Cabral Rosa Machado
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14049-900, Brazil.
| | - Klaus Hartmann Hartfelder
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14049-900, Brazil.
| | - Jorge Cury de Almeida
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14049-900, Brazil.
| | - Maria Luisa Paçó-Larson
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14049-900, Brazil.
| | - Nadia Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP CEP 14040-903, Brazil.
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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.
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