Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Biol Chem ; 291(8): 4004-18, 2016 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-26655717

RESUMO

Impaired function of the Ikaros (IKZF1) protein is associated with the development of high-risk B-cell precursor acute lymphoblastic leukemia (B-ALL). The mechanisms of Ikaros tumor suppressor activity in leukemia are unknown. Ikaros binds to the upstream regulatory elements of its target genes and regulates their transcription via chromatin remodeling. Here, we report that Ikaros represses transcription of the histone H3K4 demethylase, JARID1B (KDM5B). Transcriptional repression of JARID1B is associated with increased global levels of H3K4 trimethylation. Ikaros-mediated repression of JARID1B is dependent on the activity of the histone deacetylase, HDAC1, which binds to the upstream regulatory element of JARID1B in complex with Ikaros. In leukemia, JARID1B is overexpressed, and its inhibition results in cellular growth arrest. Ikaros-mediated repression of JARID1B in leukemia is impaired by pro-oncogenic casein kinase 2 (CK2). Inhibition of CK2 results in increased binding of the Ikaros-HDAC1 complex to the promoter of JARID1B, with increased formation of trimethylated histone H3 lysine 27 and decreased histone H3 Lys-9 acetylation. In cases of high-risk B-ALL that carry deletion of one Ikaros (IKZF1) allele, targeted inhibition of CK2 restores Ikaros binding to the JARID1B promoter and repression of JARID1B. In summary, the presented data suggest a mechanism through which Ikaros and HDAC1 regulate the epigenetic signature in leukemia: via regulation of JARID1B transcription. The presented data identify JARID1B as a novel therapeutic target in B-ALL and provide a rationale for the use of CK2 inhibitors in the treatment of high-risk B-ALL.


Assuntos
Caseína Quinase II/metabolismo , Epigênese Genética , Regulação Enzimológica da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Histona Desacetilase 1/metabolismo , Fator de Transcrição Ikaros/metabolismo , Histona Desmetilases com o Domínio Jumonji/biossíntese , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/biossíntese , Proteínas Repressoras/biossíntese , Transcrição Gênica , Caseína Quinase II/genética , Histona Desacetilase 1/genética , Humanos , Fator de Transcrição Ikaros/genética , Histona Desmetilases com o Domínio Jumonji/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Proteínas Repressoras/genética , Células U937
2.
Blood ; 126(15): 1813-22, 2015 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-26219304

RESUMO

Ikaros (IKZF1) is a tumor suppressor that binds DNA and regulates expression of its target genes. The mechanism of Ikaros activity as a tumor suppressor and the regulation of Ikaros function in leukemia are unknown. Here, we demonstrate that Ikaros controls cellular proliferation by repressing expression of genes that promote cell cycle progression and the phosphatidylinositol-3 kinase (PI3K) pathway. We show that Ikaros function is impaired by the pro-oncogenic casein kinase II (CK2), and that CK2 is overexpressed in leukemia. CK2 inhibition restores Ikaros function as transcriptional repressor of cell cycle and PI3K pathway genes, resulting in an antileukemia effect. In high-risk leukemia where one IKZF1 allele has been deleted, CK2 inhibition restores the transcriptional repressor function of the remaining wild-type IKZF1 allele. CK2 inhibition demonstrated a potent therapeutic effect in a panel of patient-derived primary high-risk B-cell acute lymphoblastic leukemia xenografts as indicated by prolonged survival and a reduction of leukemia burden. We demonstrate the efficacy of a novel therapeutic approach for high-risk leukemia: restoration of Ikaros tumor suppressor activity via inhibition of CK2. These results provide a rationale for the use of CK2 inhibitors in clinical trials for high-risk leukemia, including cases with deletion of one IKZF1 allele.


Assuntos
Caseína Quinase II/antagonistas & inibidores , Genes Supressores de Tumor , Fator de Transcrição Ikaros/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Animais , Apoptose/efeitos dos fármacos , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Proliferação de Células/efeitos dos fármacos , Imunoprecipitação da Cromatina , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Fator de Transcrição Ikaros/genética , Camundongos , Camundongos Endogâmicos NOD , Fosfatidilinositol 3-Quinases , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
3.
IUBMB Life ; 66(6): 415-23, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24916949

RESUMO

Activation of the AMP-dependent protein kinase (AMPK) is linked to cancer cell survival in a variety of cancer cell lines, particularly under conditions of stress. As a potent activator of AMPK, metformin has become a hot topic of discussion for its effect on cancer cell. Here, we report that AMPK activated by metformin promotes HeLa-S3 cell survival and growth in vivo. Our results show that metformin inhibited cell proliferation in MCF-7 cells, but not in LKB1-deficient HeLa-S3 cells. Re-expression of LKB-1 in HeLa-S3 cells restored the growth inhibitory effect of metformin, indicating a requirement for LKB-1 in metformin-induced growth inhibition. Moreover, AMPK activation exerted a protective effect in HeLa-S3 cells by relieving ER stress, modulating ER Ca(2+) storage, and finally contributing to cellular adaptation and resistance to apoptosis. Our findings identify a link between AMPK activation and cell survival in HeLa-S3 cells, which demonstrates a beneficial effect of AMPK activated by metformin in cancer cell, and suggests a discrete re-evaluation on the role of metformin/AMPK activation on tumor cell growth, proliferation, and on clinical application in cancer therapy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ativação Enzimática/efeitos dos fármacos , Células HeLa/enzimologia , Células HeLa/fisiologia , Metformina/farmacologia , Western Blotting , Cálcio/metabolismo , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Humanos , Imuno-Histoquímica , Células MCF-7
4.
J Neuropathol Exp Neurol ; 83(7): 567-578, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38833313

RESUMO

We report the novel clinical presentation of a primary brain neoplasm in a 30-year-old man with a mass-like area in the anteromedial temporal lobe. Histopathological analysis revealed a low-grade neuroepithelial tumor with cytologically abnormal neurons and atypical glial cells within the cerebral cortex. Molecular analysis showed a previously undescribed FGFR2::DLG5 rearrangement. We discuss the clinical significance and molecular implications of this fusion event, shedding light on its potential impact on tumor development and patient prognosis. Additionally, an extensive review places the finding in this case in the context of protein fusions in brain tumors in general and highlights their diverse manifestations, underlying molecular mechanisms, and therapeutic implications.


Assuntos
Neoplasias Encefálicas , Neoplasias Neuroepiteliomatosas , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Humanos , Masculino , Adulto , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/patologia , Proteínas de Fusão Oncogênica/genética
5.
J Mol Diagn ; 26(2): 140-149, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38008285

RESUMO

Detection of cancer-associated gene fusions is crucial for diagnosis, prognosis, and treatment selection. Many bioinformatics tools are available for the detection of fusion transcripts by RNA sequencing, but there are fewer well-validated software tools for DNA next-generation sequencing (NGS). A 542-gene solid tumor NGS panel was designed, with exonic probes supplemented with intronic bait probes against genes commonly involved in oncogenic fusions, with a focus on lung cancer. Three software tools for the detecting gene fusions in this DNA-NGS panel were selected and evaluated. The performance of these tools was compared after a pilot study, and each was configured for optimal batch analysis and detection rate. A blacklist for filtering common tool-specific artifacts, and criteria for selecting clinically reportable fusions, were established. Visualization tools for annotating and confirming somatic fusions were applied. Subsequently, a full clinical validation was used for comparing the results to those from in situ hybridization and/or RNA sequencing. With JuLI, Factera, and GeneFuse, 94.1%, 88.2%, and 66.7% of expected fusions were detected, respectively. With a combinatorial pipeline (termed FindDNAFusion), developed by integrating fusion-calling tools with methods for fusion filtering, annotating, and flagging reportable calls, the accuracy of detection of intron-tiled genes was improved to 98.0%. FindDNAFusion is an accurate and efficient tool in detecting somatic fusions in DNA-NGS panels with intron-tiled bait probes when RNA is unavailable.


Assuntos
Neoplasias Pulmonares , Software , Humanos , Projetos Piloto , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Fusão Gênica , DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Genômica/métodos
6.
Sci Total Environ ; 801: 149757, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34467932

RESUMO

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in more than 129 million confirm cases. Many health authorities around the world have implemented wastewater-based epidemiology as a rapid and complementary tool for the COVID-19 surveillance system and more recently for variants of concern emergence tracking. In this study, three SARS-CoV-2 target genes (N1 and N2 gene regions, and E gene) were quantified from wastewater influent samples (n = 250) obtained from the capital city and 7 other cities in various size in central Ohio from July 2020 to January 2021. To determine human-specific fecal strength in wastewater samples more accurately, two human fecal viruses (PMMoV and crAssphage) were quantified to normalize the SARS-CoV-2 gene concentrations in wastewater. To estimate the trend of new case numbers from SARS-CoV-2 gene levels, different statistical models were built and evaluated. From the longitudinal data, SARS-CoV-2 gene concentrations in wastewater strongly correlated with daily new confirmed COVID-19 cases (average Spearman's r = 0.70, p < 0.05), with the N2 gene region being the best predictor of the trend of confirmed cases. Moreover, average daily case numbers can help reduce the noise and variation from the clinical data. Among the models tested, the quadratic polynomial model performed best in correlating and predicting COVID-19 cases from the wastewater surveillance data, which can be used to track the effectiveness of vaccination in the later stage of the pandemic. Interestingly, neither of the normalization methods using PMMoV or crAssphage significantly enhanced the correlation with new case numbers, nor improved the estimation models. Viral sequencing showed that shifts in strain-defining variants of SARS-CoV-2 in wastewater samples matched those in clinical isolates from the same time periods. The findings from this study support that wastewater surveillance is effective in COVID-19 trend tracking and provide sentinel warning of variant emergence and transmission within various types of communities.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Ohio , Águas Residuárias , Vigilância Epidemiológica Baseada em Águas Residuárias
7.
J Struct Funct Genomics ; 11(4): 241-5, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20945103

RESUMO

The identification of sequence-based protein domains and their boundaries is often a prelude to structure determination. An accurate prediction of disordered regions, secondary structures and low complexity segments of target protein sequences can improve the efficiency of selection in structural genomics and also aid in design of constructs for directed structural biology studies. At the Center for Eukaryotic Structural Genomics (CESG) we have developed DomainView, a web tool to visualize and analyze predicted protein domains, disordered regions, secondary structures and low complexity segments of target protein sequences for selection of experimental protein structure attempts. DomainView consists of a relational database and a web graphical-user interface. The database was developed based on MySQL, which stores data from target protein sequences and their domains, disordered regions, secondary structures and low complexity segments. The program of the web user interface is a Perl CGI script. When a user searches for a target protein sequence, the script displays the combinational information about the domains and other features of that target sequence graphically on a web page by querying the database. The graphical representation for each feature is linked to a web page showing more detailed annotation information or to a new window directly running the corresponding prediction program to show further information about that feature.


Assuntos
Biologia Computacional/métodos , Bases de Dados de Proteínas , Estrutura Terciária de Proteína , Sequência de Aminoácidos , Gráficos por Computador , Internet , Software , Interface Usuário-Computador
8.
Cancers (Basel) ; 12(11)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126432

RESUMO

Leukemia-associated alternative splicing of IKZF1 can result in proteins with loss of one to four copies of its N-terminal zinc finger domains (N-ZnF). The best characterized pathogenic splice isoforms, Ik-6 and Ik-8, have been commonly found in BCR-ABL1+ acute lymphoblastic leukemia (ALL) and a subset of BCR-ABL1-like ALL. Infantile and childhood ALL that express these pathogenic IKZF1 isoforms have shown inferior clinical outcomes and can be resistant to tyrosine kinase inhibitors. Using ALL cell lines, we designed and validated a method to detect abnormal IKZF1 transcripts. In the SUP-B15 leukemia cell line, we noted novel IKZF1 transcripts that include both an Ik-6 splice and a transcript with a 14 base pair insertion at the C-terminus. There was also increased IKZF2 protein in SUP-B15 as compared to other ALL lines. Expression of Ik-6 could be suppressed by treatment with the pro-apoptotic type II histone deacetylase inhibitor givinostat. In 17 adult ALL samples, we noted the Ik-6 isoforms in 6 of 15 BCR-ABL1-, and 1 of 2 BCR-ABL1+ cases, with Ik-8 also expressed in one case. Cases with Ik-6 expression showed inferior survival as well as older age at presentation, lower expression of CD10 and more commonly a diploid karyotype.

9.
Sci Rep ; 8(1): 395, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29321689

RESUMO

Smooth muscle cells (SMCs) and endothelial cells (ECs) are vital cell types composing the vascular medial wall and the atheroprotective inner lining, respectively. Current treatments for cardiovascular disease inhibit SMC hyperplasia but compromise EC integrity, predisposing patients to thrombosis. Therapeutics targeting SMCs without collateral damage to ECs are highly desirable. However, differential (SMC versus EC) disease-associated regulations remain poorly defined. We conducted RNA-seq experiments to investigate SMC-versus-EC differential transcriptomic dynamics, following treatment of human primary SMCs and ECs with TNFα or IL-1ß, both established inducers of SMC hyperplasia and EC dysfunction. As revealed by combined SMC/EC transcriptomes, after TNFα or IL-1ß induction, 174 and 213 genes respectively showed greater up-regulation in SMCs than in ECs (SMC-enriched), while 117 and 138 genes showed greater up-regulation in ECs over SMCs (EC-enriched). Analysis of gene interaction networks identified central genes shared in the two SMC-enriched gene sets, and a distinct group of central genes common in the two EC-enriched gene sets. Significantly, four gene modules (subnetworks) were identified from these central genes, including SMC-enriched JUN and FYN modules and EC-enriched SMAD3 and XPO1 modules. These modules may inform potential intervention targets for selective blockage of SMC hyperplasia without endothelial damage.


Assuntos
Citocinas/farmacologia , Endotélio Vascular/citologia , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/efeitos dos fármacos , Músculo Liso Vascular/citologia , Análise de Sequência de RNA/métodos , Linhagem Celular , Células Endoteliais/química , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/química , Endotélio Vascular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1beta/farmacologia , Músculo Liso Vascular/química , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/química , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Especificidade de Órgãos , Fator de Necrose Tumoral alfa/farmacologia
10.
Int J Nurs Sci ; 4(4): 378-383, 2017 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31406781

RESUMO

OBJECTIVES: This study aims to investigate the environmental and individual factors contributing to male nurses' psychological well-being and to explore the psychological mechanisms that may explain the links between nurses' practice environment and work engagement, thereby presenting the implications for nurse managers. METHODS: A total of 161 male nurses from three tertiary first-class hospitals in Changsha City in China participated in the study. We collected the data using the Practice Environment Scale of the Nursing Work Index, the Psychological Capital Questionnaire, and the Utrecht Work Engagement Scale. RESULTS: Scores of male nurses' practice environment (2.88 ± 0.31), psychological capital (4.42 ± 0.62), and work engagement (3.17 ± 1.39) were all above the midpoint; however, the subscales "the nursing staffing and resources adequacy" (2.72 ± 0.48), "hope" (4.33 ± 0.72), and "dedication" (2.96 ± 1.61)scored lowest. Nurses' practice environment and psychological capital positively predicted nurses' work engagement; psychological capital fully mediated the influence of nurses' practice environment on work engagement. CONCLUSIONS: Creating a supportive nursing practice environment can increase male nurses' work engagement by developing their psychological capital. Nurse managers can then provide reasonable workload and pathways for male nurses to achieve goals, thereby fostering their hope.

12.
Nucleic Acids Res ; 31(4): 1245-51, 2003 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12582244

RESUMO

Insertional mutagenesis techniques, including transposon- and T-DNA-mediated mutagenesis, are key resources for systematic identification of gene function in the model plant species Arabidopsis thaliana. We have developed a database (http://atidb.cshl.org/) for archiving, searching and analyzing insertional mutagenesis lines. Flanking sequences from approximately 10 500 insertion lines (including transposon and T-DNA insertions) from several tagging programs in Arabidopsis were mapped to the genome sequence through our annotation system before being entered into the database. The database front end provides World Wide Web searching and analyzing interfaces for genome researchers and other biologists. Users can search the database to identify insertions in a particular gene or perform genome-wide analysis to study the distribution and preference of insertions. Tools integrated with the database include a graphical genome browser, a protein search function, a graphical representation of the insertion distribution and a Blast search function. The database is based on open source components and is available under an open source license.


Assuntos
Arabidopsis/genética , Bases de Dados Factuais , Mutagênese Insercional/genética , Sequência de Aminoácidos , Sítios de Ligação/genética , Genoma de Planta , Internet , Dados de Sequência Molecular
13.
Nucleic Acids Res ; 30(1): 103-5, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11752266

RESUMO

Gramene (http://www.gramene.org) is a comparative genome mapping database for grasses and a community resource for rice. Rice, in addition to being an economically important crop, is also a model monocot for understanding other agronomically important grass genomes. Gramene replaces the existing AceDB database 'RiceGenes' with a relational database based on Oracle. Gramene provides curated and integrative information about maps, sequence, genes, genetic markers, mutants, QTLs, controlled vocabularies and publications. Its aims are to use the rice genetic, physical and sequence maps as fundamental organizing units, to provide a common denominator for moving from one crop grass to another and is to serve as a portal for interconnecting with other web-based crop grass resources. This paper describes the initial steps we have taken towards realizing these goals.


Assuntos
Bases de Dados Genéticas , Genoma de Planta , Oryza/genética , Poaceae/genética , Mapeamento Cromossômico , Gráficos por Computador , Sistemas de Gerenciamento de Base de Dados , Previsões , Genes de Plantas , Marcadores Genéticos , Armazenamento e Recuperação da Informação , Internet , Mutação , Característica Quantitativa Herdável , Homologia de Sequência
14.
J Struct Funct Genomics ; 8(4): 209-16, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18236171

RESUMO

Determination of a protein structure requires a series of decisions and processes, starting with target selection, through cloning, expression, purification, and finally structure determination. Structural genomics projects may distribute these steps among several different groups of researchers. Although this division may achieve a lower cost per solved structure, it creates a unique set of challenges for integrating and passing information on the progress of a given target across several functional divisions. Laboratory information management systems (LIMS) are essential for gathering this information, but may not display the progress of a given target in an intuitive way. In addition, structural genomics projects funded by the Protein Structure Initiative (PSI) are obliged to disseminate data regularly to the TargetDB and PepcDB data repositories, and this requires the creation of specialized views of the data. We report here how the flow of a target through a structural genomics pipeline and reports to TargetDB and PepcDB can be abstracted as directed acyclic graphs or trees. To implement this kind of display, we created software that tracks the flow of activity leading toward protein structure determination and prepares XML reports as input to TargetDB and PepcDB. The target tracing software consists of a set of Perl CGI scripts that integrate with the Graphviz visualization system to provide a graphical, user-friendly Web interface. The database reporting software, also coded in Perl, transfers large-scale genomics data from our LIMS into a PepcDB reportable XML file. This software package has facilitated inter-group communication, improved the quality and accuracy of information in our LIMS, and increased the efficiency and accuracy of our reports to PepcDB.


Assuntos
Sistemas de Gerenciamento de Base de Dados , Bases de Dados de Proteínas , Genômica , Armazenamento e Recuperação da Informação/métodos , Proteínas/química , Proteínas/metabolismo , Software
15.
Bioinformatics ; 21(17): 3461-8, 2005 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-15994196

RESUMO

MOTIVATION: The recent efforts of various sequence projects to sequence deeply into various phylogenies provide great resources for comparative sequence analysis. A generic and portable tool is essential for scientists to visualize and analyze sequence comparisons. RESULTS: We have developed SynBrowse, a synteny browser for visualizing and analyzing genome alignments both within and between species. It is intended to help scientists study macrosynteny, microsynteny and homologous genes between sequences. It can also aid with the identification of uncharacterized genes, putative regulatory elements and novel structural features of a species. SynBrowse is a GBrowse (the Generic Genome Browser) family software tool that runs on top of the open source BioPerl modules. It consists of two components: a web-based front end and a set of relational database back ends. Each database stores pre-computed alignments from a focus sequence to reference sequences in addition to the genome annotations of the focus sequence. The user interface lets end users select a key comparative alignment type and search for syntenic blocks between two sequences and zoom in to view the relationships among the corresponding genome annotations in detail. SynBrowse is portable with simple installation, flexible configuration, convenient data input and easy integration with other components of a model organism system. AVAILABILITY: The software is available at http://www.gmod.org CONTACT: vbrendel@iastate.edu


Assuntos
Mapeamento Cromossômico/métodos , Alinhamento de Sequência/métodos , Análise de Sequência de DNA/métodos , Software , Sintenia/genética , Interface Usuário-Computador , Algoritmos , Sequência de Bases , Gráficos por Computador , Dados de Sequência Molecular
16.
Plant Physiol ; 137(1): 168-75, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15618417

RESUMO

We have performed a comparative analysis of the insertion sites of engineered Arabidopsis (Arabidopsis thaliana) insertional mutagenesis vectors that are based on the maize (Zea mays) transposable elements and Agrobacterium T-DNA. The transposon-based agents show marked preference for high GC content, whereas the T-DNA-based agents show preference for low GC content regions. The transposon-based agents show a bias toward insertions near the translation start codons of genes, while the T-DNAs show a predilection for the putative transcriptional regulatory regions of genes. The transposon-based agents also have higher insertion site densities in exons than do the T-DNA insertions. These observations show that the transposon-based and T-DNA-based mutagenesis techniques could complement one another well, and neither alone is sufficient to achieve the goal of saturation mutagenesis in Arabidopsis. These results also suggest that transposon-based mutagenesis techniques may prove the most effective for obtaining gene disruptions and for generating gene traps, while T-DNA-based agents may be more effective for activation tagging and enhancer trapping. From the patterns of insertion site distributions, we have identified a set of nucleotide sequence motifs that are overrepresented at the transposon insertion sites. These motifs may play a role in the transposon insertion site preferences. These results could help biologists to study the mechanisms of insertions of the insertional mutagenesis agents and to design better strategies for genome-wide insertional mutagenesis.


Assuntos
Arabidopsis/genética , Mutagênese Insercional/genética , Sequência de Bases , Elementos de DNA Transponíveis/fisiologia , DNA Bacteriano/química
17.
Comp Funct Genomics ; 3(2): 132-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-18628886

RESUMO

Gramene (http://www.gramene.org/) is a comparative genome database for cereal crops and a community resource for rice. We are populating and curating Gramene with annotated rice (Oryza sativa) genomic sequence data and associated biological information including molecular markers, mutants, phenotypes, polymorphisms and Quantitative Trait Loci (QTL). In order to support queries across various data sets as well as across external databases, Gramene will employ three related controlled vocabularies. The specific goal of Gramene is, first to provide a Trait Ontology (TO) that can be used across the cereal crops to facilitate phenotypic comparisons both within and between the genera. Second, a vocabulary for plant anatomy terms, the Plant Ontology (PO) will facilitate the curation of morphological and anatomical feature information with respect to expression, localization of genes and gene products and the affected plant parts in a phenotype. The TO and PO are both in the early stages of development in collaboration with the International Rice Research Institute, TAIR and MaizeDB as part of the Plant Ontology Consortium. Finally, as part of another consortium comprising macromolecular databases from other model organisms, the Gene Ontology Consortium, we are annotating the confirmed and predicted protein entries from rice using both electronic and manual curation.

18.
Proc Natl Acad Sci U S A ; 100(20): 11541-6, 2003 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-12954979

RESUMO

We describe an efficient system for site-selected transposon mutagenesis in maize. A total of 43,776 F1 plants were generated by using Robertson's Mutator (Mu) pollen parents and self-pollinated to establish a library of transposon-mutagenized seed. The frequency of new seed mutants was between 10-4 and 10-5 per F1 plant. As a service to the maize community, maize-targeted mutagenesis selects insertions in genes of interest from this library by using the PCR. Pedigree, knockout, sequence, phenotype, and other information is stored in a powerful interactive database (maize-targeted mutagenesis database) that enables analysis of the entire population and the handling of knockout requests. By inhibiting Mu activity in most F1 plants, we sought to reduce somatic insertions that may cause false positives selected from pooled tissue. By monitoring the remaining Mu activity in the F2, however, we demonstrate that seed phenotypes depend on it, and false positives occur in lines that appear to lack it. We conclude that more than half of all mutations arising in this population are suppressed on losing Mu activity. These results have implications for epigenetic models of inbreeding and for functional genomics.


Assuntos
Elementos de DNA Transponíveis , Mutagênese Insercional , Zea mays/genética , Sequência de Bases , Primers do DNA , Fenótipo , Reação em Cadeia da Polimerase
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA