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1.
J Evol Biol ; 26(12): 2606-21, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24118176

RESUMO

Recent progress in methods for detecting adaptive population divergence in situ shows promise for elucidating the conditions under which selection acts to generate intraspecific diversity. Rapid ecological diversification is common in fishes; however, the role of phenotypic plasticity and adaptation to local environments is poorly understood. It is now possible to investigate genetic patterns to make inferences regarding phenotypic traits under selection and possible mechanisms underlying ecotype divergence, particularly where similar novel phenotypes have arisen in multiple independent populations. Here, we employed a bottom-up approach to test for signatures of directional selection associated with divergence of beach- and stream-spawning kokanee, the obligate freshwater form of sockeye salmon (Oncorhynchus nerka). Beach- and stream-spawners co-exist in many post-glacial lakes and exhibit distinct reproductive behaviours, life-history traits and spawning habitat preferences. Replicate ecotype pairs across five lakes in British Columbia, Canada were genotyped at 57 expressed sequence tag-linked and anonymous microsatellite loci identified in a previous genome scan. Fifteen loci exhibited signatures of directional selection (high FST outliers), four of which were identified in multiple lakes. However, the lack of parallel genetic patterns across all lakes may be a result of: 1) an inability to detect loci truly under selection; 2) alternative genetic pathways underlying ecotype divergence in this system; and/or 3) phenotypic plasticity playing a formative role in driving kokanee spawning habitat differences. Gene annotations for detected outliers suggest pathogen resistance and energy metabolism as potential mechanisms contributing to the divergence of beach- and stream-spawning kokanee, but further study is required.


Assuntos
Ecologia , Reprodução , Salmão/fisiologia , Animais , Colúmbia Britânica , Geografia , Filogenia , Salmão/classificação , Salmão/genética
2.
Nat Genet ; 9(4): 424-31, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7795650

RESUMO

High plasma concentrations of apolipoprotein (a) (apo(a)) have been implicated as a major independent risk factor for atherosclerosis in humans. Apo(a) is a large, evolutionarily new gene (present primarily in primates) for which considerable controversy exists concerning the factors that regulate its expression. To investigate the in vivo regulation of apo(a), we have created several lines of YAC transgenic mice containing a 110-kb human apo(a) gene surrounded by greater than 60 kb of 5' and 3' flanking DNA. Studies in humans have suggested that acute-phase inducers increase and sex steroids decrease apo(a) concentrations, but these results are controversial. Analysis of the YAC transgenic mice conclusively supports the hypothesized role of sex steroids and refutes the suggested role of acute-phase inducers in regulating the apo(a) gene.


Assuntos
Reação de Fase Aguda/genética , Apolipoproteínas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônios Esteroides Gonadais/farmacologia , Lipoproteína(a) , Animais , Apoproteína(a) , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Artificiais de Levedura , Primers do DNA/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Distribuição Tecidual
3.
Nat Genet ; 23(2): 241-4, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10508526

RESUMO

Many quantitative trait loci (QTLs) contributing to genetically complex conditions have been discovered, but few causative genes have been identified. This is mainly due to the large size of QTLs and the subtle connection between genotype and quantitative phenotype associated with these conditions. Transgenic mice have been successfully used to analyse well-characterized genes suspected of contributing to quantitative traits. Although this approach is powerful for examining one gene at a time, it can be impractical for surveying the large genomic intervals containing many genes that are typically associated with QTLs. To screen for genes contributing to an asthma QTL mapped to human chromosome 5q3 (refs 6,7), we characterized a panel of large-insert 5q31 transgenics based on studies demonstrating that altering gene dosage frequently affects quantitative phenotypes normally influenced by that gene. This panel of human YAC transgenics, propagating a 1-Mb interval of chromosome 5q31 containing 6 cytokine genes and 17 partially characterized genes, was screened for quantitative changes in several asthma-associated phenotypes. Multiple independent transgenic lines with altered IgE response to antigen treatment shared a 180-kb region containing 5 genes, including those encoding human interleukin 4 (IL4) and interleukin 13 (IL13 ), which induce IgE class switching in B cells. Further analysis of these mice and mice transgenic for mouse Il4 and Il13 demonstrated that moderate changes in Il4 and Il13 expression affect asthma-associated phenotypes in vivo. This functional screen of large-insert transgenics enabled us to identify genes that influence the QTL phenotype in vivo.


Assuntos
Asma/genética , Característica Quantitativa Herdável , Animais , Asma/fisiopatologia , Testes de Provocação Brônquica , Broncoconstrição/efeitos dos fármacos , Cromossomos Artificiais de Levedura , Citometria de Fluxo , Expressão Gênica , Testes Genéticos , Humanos , Imunoglobulina E/sangue , Interleucina-13/genética , Interleucina-4/genética , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , RNA/genética , RNA/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismo , Células Th2/citologia , Células Th2/efeitos dos fármacos , Células Th2/metabolismo
4.
Prev Med Rep ; 32: 102158, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36875512

RESUMO

There is growing evidence that smoking cessation (SC) improves outcomes following diagnosis of cancer. Notwithstanding adverse outcomes, a significant number of those diagnosed with cancer continue to smoke. Our objective was to document the SC services provided for patients with cancer by specialist adult cancer hospitals across Ireland, a country with a stated tobacco endgame goal. A cross-sectional survey based on recent national clinical guidelines was used to determine SC care delivery across eight adult cancer specialist hospitals, and one specialist radiotherapy centre. Qualtrics was used. The response rate was 88.9% with data reported from seven cancer hospitals and one specialist radiotherapy centre, all indicating they had some SC related provision (100%). Stop smoking medications were provided to cancer inpatients in two hospitals, at outpatients and attending day ward services in one hospital. Smokers with cancer were referred automatically to the SC service in two hospitals at diagnosis. While stop smoking medications were available 24 h a day in five hospitals, most did not stock all three (Nicotine Replacement Therapy, Bupropion, Varenicline). One hospital advised they had data on uptake of SC services for smokers with cancer but were unable to provide detail. There is considerable variation in SC information and services provided to cancer patients across adult cancer specialist centres in Ireland, reflecting the suboptimal practice of smoking cessation for patients with cancer found in the limited international audits. Such audits are essential to demonstrate service gaps and provide a baseline for service improvement.

5.
J Cell Biol ; 107(2): 687-97, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3417768

RESUMO

A major laminin-binding protein (LBP), distinct from previously described LBPs, has been isolated from chick and rat skeletal muscle (Mr 56,000 and 66,000, respectively). The purified LBPs from the two species were shown to be related antigenically and to have similar NH2-terminal amino acid sequences and total amino acid compositions. Protein blots using laminin and laminin fragments provided evidence that this LBP interacts with the major heparin-binding domain, E3, of laminin. Studies on the association of this LBP with muscle membrane fractions and reconstituted lipid vesicles indicate that this protein can interact with lipid bilayers and has properties of a peripheral, not an integral membrane protein. These properties are consistent with its amino acid sequence, determined from cDNAs (Clegg et al., 1988). Examination by light and electron microscopy of the LBP antigen distribution in skeletal muscle indicated that the protein is localized primarily extracellularly, near the extracellular matrix and myotube plasmalemma. While a form of this LBP has been identified in heart muscle, it is present at low or undetectable levels in other tissues examined by immunocytochemistry indicating that it is probably a muscle-specific protein. As this protein is localized extracellularly and can bind to both membranes and laminin, it may mediate myotube interactions with the extracellular matrix.


Assuntos
Proteínas de Transporte/isolamento & purificação , Laminina/metabolismo , Músculos/análise , Sequência de Aminoácidos , Animais , Autorradiografia , Proteínas de Ligação ao Cálcio , Calsequestrina , Proteínas de Transporte/análise , Membrana Celular/análise , Centrifugação com Gradiente de Concentração , Galinhas , Cromatografia DEAE-Celulose , Eletroforese em Gel de Poliacrilamida , Matriz Extracelular/análise , Feminino , Imunoensaio , Imuno-Histoquímica , Proteínas de Membrana/análise , Microscopia Eletrônica , Dados de Sequência Molecular , Peso Molecular , Músculos/ultraestrutura , Coelhos , Ratos
6.
Science ; 288(5463): 136-40, 2000 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-10753117

RESUMO

Long-range regulatory elements are difficult to discover experimentally; however, they tend to be conserved among mammals, suggesting that cross-species sequence comparisons should identify them. To search for regulatory sequences, we examined about 1 megabase of orthologous human and mouse sequences for conserved noncoding elements with greater than or equal to 70% identity over at least 100 base pairs. Ninety noncoding sequences meeting these criteria were discovered, and the analysis of 15 of these elements found that about 70% were conserved across mammals. Characterization of the largest element in yeast artificial chromosome transgenic mice revealed it to be a coordinate regulator of three genes, interleukin-4, interleukin-13, and interleukin-5, spread over 120 kilobases.


Assuntos
Proteínas de Ligação a DNA , Interleucina-13/genética , Interleucina-4/genética , Interleucina-5/genética , Sequências Reguladoras de Ácido Nucleico , Proteínas de Saccharomyces cerevisiae , Animais , Sequência de Bases , Cromossomos Humanos Par 5/genética , Sequência Conservada , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Regulação da Expressão Gênica , Humanos , Interleucina-13/biossíntese , Interleucina-4/biossíntese , Interleucina-5/biossíntese , Cinesinas/biossíntese , Cinesinas/genética , Camundongos , Camundongos Transgênicos , Mapeamento Físico do Cromossomo , Especificidade da Espécie , Células Th1/imunologia , Células Th2/imunologia , Transgenes
7.
Science ; 294(5547): 1719-23, 2001 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-11721056

RESUMO

Global patterns of human DNA sequence variation (haplotypes) defined by common single nucleotide polymorphisms (SNPs) have important implications for identifying disease associations and human traits. We have used high-density oligonucleotide arrays, in combination with somatic cell genetics, to identify a large fraction of all common human chromosome 21 SNPs and to directly observe the haplotype structure defined by these SNPs. This structure reveals blocks of limited haplotype diversity in which more than 80% of a global human sample can typically be characterized by only three common haplotypes.


Assuntos
Cromossomos Humanos Par 21/genética , Haplótipos/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Polimorfismo de Nucleotídeo Único/genética , Algoritmos , Alelos , Animais , Etnicidade/genética , Frequência do Gene/genética , Variação Genética/genética , Genoma Humano , Humanos , Células Híbridas/metabolismo , Mutação/genética , Grupos Raciais/genética , Distribuição Aleatória , Sensibilidade e Especificidade
8.
J Thromb Haemost ; 16(9): 1763-1774, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29964323

RESUMO

Essentials Discovery of predictive biomarkers of venous thromboembolism (VTE) may aid risk stratification. A case-control study where plasma was sampled before the occurrence of VTE was established. We generated untargeted plasma proteomic profiles of 200 individuals by use of mass spectrometry. Assessment of the biomarker potential of 501 proteins yielded 46 biomarker candidates. ABSTRACT: Background Prophylactic anticoagulant treatment may substantially reduce the incidence of venous thromboembolism (VTE) but entails considerable risk of severe bleeding. Identification of individuals at high risk of VTE through the use of predictive biomarkers is desirable in order to achieve a favorable benefit-to-harm ratio. Objective We aimed to identify predictive protein biomarker candidates of VTE. Methods We performed a case-control study of 200 individuals that participated in the Tromsø Study, a population-based cohort, where blood samples were collected before the VTE events occurred. Untargeted tandem mass tag-synchronous precursor selection-mass spectrometry (TMT-SPS-MS3)-based proteomic profiling was used to study the plasma proteomes of each individual. Results Of the 501 proteins detected in a sufficient number of samples to allow multivariate analysis, 46 proteins were associated with VTE case-control status with P-values below the 0.05 significance threshold. The strongest predictive biomarker candidates, assessed by statistical significance, were transthyretin, vitamin K-dependent protein Z and protein/nucleic acid deglycase DJ-1. Conclusions Our untargeted approach of plasma proteome profiling revealed novel predictive biomarker candidates of VTE and confirmed previously reported candidates, thereby providing conceptual support for the validity of the study. A larger nested case-control study will be conducted to validate our findings.


Assuntos
Biomarcadores/sangue , Proteínas Sanguíneas/análise , Proteômica/métodos , Embolia Pulmonar/sangue , Espectrometria de Massas em Tandem/métodos , Tromboembolia Venosa/sangue , Trombose Venosa/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Prognóstico , Estudos Prospectivos , Medição de Risco
9.
J Thromb Haemost ; 16(1): 83-89, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29094466

RESUMO

Essentials Body height and prothrombotic genotypes are associated with risk of venous thromboembolism (VTE). The joint effect of prothrombotic genotypes and tall stature on VTE risk is scarcely investigated. We investigated the joint effect of prothrombotic genotypes and tall stature on VTE risk. Prothrombotic genotypes did not yield excess risk of VTE in subjects with a tall stature. SUMMARY: Background Studies have reported synergistic effects of prothrombotic single-nucleotide polymorphisms (SNPs) and obesity on the risk of venous thromboembolism (VTE). Tall stature is associated with an increased VTE risk, but the joint effect of prothrombotic genotypes and tall stature on the VTE risk is unknown. Aims To investigate the joint effects of prothrombotic genotypes and tall stature on the VTE risk. Methods Cases with incident VTE (n = 676) and a randomly selected age-weighted subcohort (n = 1842) were sampled from the Tromsø study (cohort follow-up: 1994-2012). DNA was genotyped for rs6025 (factor V Leiden), rs1799963 (FII), rs8176719 (ABO blood group), rs2066865 (fibrinogen-γ), and rs2036914 (FIX). Age-adjusted and sex-adjusted hazard ratios (HRs) of VTE were calculated by categories of risk alleles (de Haan 5-SNP score: 0-1, 2-3, and ≥ 4) and body height (< 40th, 40th-80th and > 80th percentiles). Results The VTE risk increased by increasing category of body height, and subjects with height ≥ 178 cm had a two-fold higher VTE risk (HR 2.03; 95% confidence interval [CI] 1.51-2.73) than those with height ≤ 165 cm. The VTE risk also increased across categories of risk alleles. However, the combination of a tall stature and risk alleles, either individual SNPs or risk score, did not result in an excess VTE risk. Subjects with four or more risk alleles and height ≥ 178 cm had a two-fold (HR 2.08; 95% CI 1.24-3.52) higher VTE risk than subjects ≤ 165 cm with no risk allele or one risk allele. Conclusions In contrast to obesity, the presence of prothrombotic genotypes did not result in an excess VTE risk in subjects with a tall stature.


Assuntos
Estatura , Polimorfismo de Nucleotídeo Único , Tromboembolia Venosa/genética , Sistema ABO de Grupos Sanguíneos/genética , Idoso , Estudos de Casos e Controles , Fator IX/genética , Fator V/genética , Feminino , Fibrinogênio/genética , Predisposição Genética para Doença , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Noruega/epidemiologia , Fenótipo , Estudos Prospectivos , Protrombina/genética , Medição de Risco , Fatores de Risco , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/fisiopatologia
10.
Nucleic Acids Res ; 33(Database issue): D471-5, 2005 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-15608240

RESUMO

The Mouse Genome Database (MGD) forms the core of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a model organism database resource for the laboratory mouse. MGD provides essential integration of experimental knowledge for the mouse system with information annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genotype (sequence) through phenotype information, including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships among genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent improvements in MGD discussed here include the enhancement of phenotype resources, the re-development of the International Mouse Strain Resource, IMSR, the update of mammalian orthology datasets and the electronic publication of classic books in mouse genetics.


Assuntos
Bases de Dados Genéticas , Genômica , Camundongos/genética , Animais , Genes , Genoma , Genótipo , Internet , Camundongos Mutantes , Fenótipo , Integração de Sistemas , Interface Usuário-Computador
11.
Nucleic Acids Res ; 32(Database issue): D476-81, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14681461

RESUMO

The Mouse Genome Database (MGD) is one component of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a community database resource for the laboratory mouse. MGD strives to provide a comprehensive knowledgebase about the mouse with experiments and data annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genetic, genotype (sequence) and phenotype information including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships between genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent developments in MGD discussed here include an extensive integration of the mouse sequence data and substantial revisions in the presentation, query and visualization of sequence data.


Assuntos
Biologia Computacional , Bases de Dados Genéticas , Genoma , Camundongos/genética , Animais , Genômica , Armazenamento e Recuperação da Informação , Internet , Biologia Molecular , Fenótipo , Terminologia como Assunto
12.
Methods Cell Biol ; 135: 451-81, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27443940

RESUMO

The Zebrafish Model Organism Database (ZFIN; zfin.org) serves as the central repository for genetic and genomic data produced using zebrafish (Danio rerio). Data in ZFIN are either manually curated from peer-reviewed publications or submitted directly to ZFIN from various data repositories. Data types currently supported include mutants, transgenic lines, DNA constructs, gene expression, phenotypes, antibodies, morpholinos, TALENs, CRISPRs, disease models, movies, and images. The rapidly changing methods of genomic science have increased the production of data that cannot readily be represented in standard journal publications. These large data sets require web-based presentation. As the central repository for zebrafish research data, it has become increasingly important for ZFIN to provide the zebrafish research community with support for their data sets and guidance on what is required to submit these data to ZFIN. Regardless of their volume, all data that are submitted for inclusion in ZFIN must include a minimum set of information that describes the data. The aim of this chapter is to identify data types that fit into the current ZFIN database and explain how to provide those data in the optimal format for integration. We identify the required and optional data elements, define jargon, and present tools and templates that can help with the acquisition and organization of data as they are being prepared for submission to ZFIN. This information will also appear in the ZFIN wiki, where it will be updated as our services evolve over time.


Assuntos
Bases de Dados Genéticas , Genômica/métodos , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Genoma/genética , Morfolinos/genética , Mutação
14.
Blood Cancer J ; 5: e303, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25860294

RESUMO

We examined genetic and epigenetic changes that occur during disease progression from indolent to aggressive forms of chronic lymphocytic leukemia (CLL) using serial samples from 27 patients. Analysis of DNA mutations grouped the leukemia cases into three categories: evolving (26%), expanding (26%) and static (47%). Thus, approximately three-quarters of the CLL cases had little to no genetic subclonal evolution. However, we identified significant recurrent DNA methylation changes during progression at 4752 CpGs enriched for regions near Polycomb 2 repressive complex (PRC2) targets. Progression-associated CpGs near the PRC2 targets undergo methylation changes in the same direction during disease progression as during normal development from naive to memory B cells. Our study shows that CLL progression does not typically occur via subclonal evolution, but that certain CpG sites undergo recurrent methylation changes. Our results suggest CLL progression may involve developmental processes shared in common with the generation of normal memory B cells.


Assuntos
Evolução Clonal/genética , Metilação de DNA/genética , Epigênese Genética , Leucemia Linfocítica Crônica de Células B/genética , Ilhas de CpG/genética , Progressão da Doença , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Mutação , Proteínas do Grupo Polycomb/genética
15.
Science ; 288(5475): 2319a, 2000 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-17769838
16.
Laryngoscope ; 103(6): 679-82, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8502103

RESUMO

The duration of the conventional caloric stimulus is too long and the termination of the stimulus is uncontrolled. This study explores the use of a brief terminal "washout" irrigation pulse at 37 degrees C which is intended to 1. shorten the duration of action of the caloric stimulus and 2. eliminate uncertainty over the magnitude and duration of the terminal portion of the thermal labyrinthine stimulus. Twelve normal subjects were tested with 1. conventional 30-second irrigations, 2. 30-second irrigations plus a "washout" pulse, and 3. temperature-switching caloric (TSC) irrigations plus a "washout" pulse. Clinical test scores were comparable with all three irrigation methods. The "washout" pulse produced only a slight shortening of the conventional 30-second irrigation responses.


Assuntos
Temperatura Corporal , Testes Calóricos/métodos , Meato Acústico Externo/fisiologia , Adulto , Testes Calóricos/instrumentação , Estudos de Avaliação como Assunto , Humanos , Monitorização Fisiológica , Canais Semicirculares/fisiologia
17.
Otolaryngol Clin North Am ; 25(3): 499-520, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1625863

RESUMO

This article reviews the epidemiology of both unilateral and bilateral (NF-2) acoustic tumors. The growth rate of acoustic tumors is examined from a clinical, radiographic, and laboratory perspective. The anatomic, histologic, and biochemical considerations as well as the influences of sex hormones on acoustic tumor formation are reviewed. Also presented are an update on the laboratory search for the NF-2 gene on chromosome 22 and recently identified DNA markers. Predictions are made concerning the potential future applications of genetic testing for prenatal or presymptomatic diagnosis of the disease that causes bilateral acoustic tumors.


Assuntos
Neuroma Acústico/etiologia , Feminino , Genes da Neurofibromatose 2/genética , Ligação Genética , Marcadores Genéticos , Hormônios Esteroides Gonadais/fisiologia , Humanos , Masculino , Neuroma Acústico/epidemiologia , Neuroma Acústico/genética
18.
Bioinformatics ; 15(2): 170-1, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10089202

RESUMO

SUMMARY: A single gene can generate multiple transcribed gene products. An extensive list of alternatively transcribed mouse genes has been generated, and is publicly available from http://www.informatics.jax.org/report.html. CONTACT: mgi-help@informatics.jax.org


Assuntos
Processamento Alternativo , Bases de Dados Factuais , Camundongos/genética , Animais , Internet
19.
Nucleic Acids Res ; 19(16): 4371-5, 1991 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-1886764

RESUMO

We describe a simple PCR based technique which can be used to isolate sequences adjacent to rare cutter sites and can subsequently be employed for the construction of long range physical maps. The method involves the ligation of an adaptor to rare cutter sequences and its use as a target for forward priming in PCR. Primers to Alu repeat elements initiate synthesis of the reverse strand. Using this technique any rare cutter site which has a repeat element within amplification range can be cloned. We have isolated six unique sequences around NotI sites from an irradiation reduced hybrid containing a fragment of human chromosome 22 and are using these for physical mapping around the Ewing's sarcoma translocation breakpoint on chromosome 22.


Assuntos
Mapeamento Cromossômico/métodos , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Células Cultivadas , Cromossomos Humanos Par 22 , Clonagem Molecular , DNA de Cadeia Simples/genética , Humanos , Células Híbridas , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico/genética , Sarcoma de Ewing/genética , Translocação Genética/genética , Células Tumorais Cultivadas
20.
Am J Hum Genet ; 51(3): 478-85, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1496981

RESUMO

The neurofibromatosis type 2 (NF2) gene has been hypothesized to be a recessive tumor suppressor, with mutations at the same locus on chromosome 22 that lead to NF2 also leading to sporadic tumors of the types seen in NF2. Flanking markers for this gene have previously been defined as D22S1 centromeric and D22S28 telomeric. Identification of subregions of this interval that are consistently rearranged in the NF2-related tumors would aid in better defining the disease locus. To this end, we have compared tumor and constitutional DNAs, isolated from 39 unrelated patients with sporadic and NF2-associated acoustic neuromas, meningiomas, schwannomas, and ependymomas, at eight polymorphic loci on chromosome 22. Two of the tumors studied revealed loss-of-heterozygosity patterns, which is consistent with the presence of chromosome 22 terminal deletions. By using additional polymorphic markers, the terminal deletion breakpoint found in one of the tumors, an acoustic neuroma from an NF2 patient, was mapped within the previously defined NF2 region. The breakpoint occurred between the haplotyped markers D22S41/D22S46 and D22S56. This finding redefines the proximal flanking marker and localizes the NF2 gene between markers D22S41/D22S46 and D22S28. In addition, we identified a sporadic acoustic neuroma that reveals a loss-of-heterozygosity pattern consistent with mitotic recombination or deletion and reduplication, which are mechanisms not previously seen in studies of these tumors. This finding, while inconsistent with models of tumorigenesis that invoke single deletions and their gene-dosage effects, lends further support to the recessive tumor-suppressor model.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 22 , Genes da Neurofibromatose 2/genética , Neoplasias do Sistema Nervoso/genética , Neurofibromatose 2/genética , Southern Blotting , Marcadores Genéticos/genética , Humanos
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