RESUMO
The expanding use of RNA interference (RNAi) in agricultural biotechnology necessitates tools for characterizing and quantifying double-stranded RNA (dsRNA)-containing transcripts that are expressed in transgenic plants. We sought to detect and quantify such transcripts in transgenic maize lines engineered to control western corn rootworm (Diabrotica virgifera virgifera LeConte) via overexpression of an inverted repeat sequence bearing a portion of the putative corn rootworm orthologue of yeast Snf7 (DvSnf7), an essential component of insect cell receptor sorting. A quantitative assay was developed to detect DvSnf7 sense strand-containing dsRNA transcripts that is based on the QuantiGene Plex 2.0 RNA assay platform from Affymetrix. The QuantiGene assay utilizes cooperative binding of multiple oligonucleotide probes with specificity for the target sequence resulting in exceptionally high assay specificity. Successful implementation of this assay required heat denaturation in the presence of the oligonucleotide probes prior to hybridization, presumably to dissociate primary transcripts carrying the duplex dsRNA structure. The dsRNA assay was validated using a strategy analogous to the rigorous enzyme-linked immunosorbent assay evaluations that are typically performed for foreign proteins expressed in transgenic plants. Validation studies indicated that the assay is sensitive (to 10 pg of dsRNA/g of fresh tissue), highly reproducible, and linear over â¼2.5 logs. The assay was validated using purified RNA from multiple maize tissue types, and studies indicate that the assay is also quantitative in crude tissue lysates. To the best of our knowledge, this is the first report of a non-polymerase chain reaction-based quantitative assay for dsRNA-containing transcripts, based on the use of the QuantiGene technology platform, and will broadly facilitate characterization of dsRNA in biological and environmental samples.
Assuntos
Besouros/genética , Proteínas de Insetos/genética , Hibridização de Ácido Nucleico/métodos , Doenças das Plantas/parasitologia , Plantas Geneticamente Modificadas/genética , RNA de Cadeia Dupla/genética , Zea mays/genética , Animais , Besouros/fisiologia , Proteínas de Insetos/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/parasitologia , RNA de Cadeia Dupla/metabolismo , Transgenes , Zea mays/metabolismo , Zea mays/parasitologiaRESUMO
We conducted genome-wide association studies of non-Hodgkin lymphoma using Illumina HumanHap550 BeadChips to identify subtype-specific associations in follicular, diffuse large B-cell and chronic lymphocytic leukemia/small lymphocytic lymphomas. We found that rs6457327 on 6p21.33 was associated with susceptibility to follicular lymphoma (FL; N = 189 cases, 592 controls) with validation in another 456 FL cases and 2,785 controls (combined allelic P = 4.7 x 10(-11)). The region of strongest association overlapped C6orf15 (STG), located near psoriasis susceptibility region 1 (PSORS1).
Assuntos
Cromossomos Humanos Par 6/genética , Predisposição Genética para Doença , Variação Genética , Linfoma Folicular/genética , Humanos , Linfoma Difuso de Grandes Células B/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
We conducted a genome-wide association pooling study for cutaneous melanoma and performed validation in samples totaling 2,019 cases and 2,105 controls. Using pooling, we identified a new melanoma risk locus on chromosome 20 (rs910873 and rs1885120), with replication in two further samples (combined P < 1 x 10(-15)). The per allele odds ratio was 1.75 (1.53, 2.01), with evidence for stronger association in early-onset cases.
Assuntos
Cromossomos Humanos Par 20 , Predisposição Genética para Doença , Melanoma/genética , Polimorfismo de Nucleotídeo Único , Neoplasias Cutâneas/genética , Adulto , Idade de Início , Estudos de Casos e Controles , Humanos , Desequilíbrio de Ligação , Razão de ChancesRESUMO
Low-copy repeats (LCRs) are genomic features that affect chromosome stability and can produce disease-associated rearrangements. We describe members of three families with deletions in 10q22.3-q23.31, a region harboring a complex set of LCRs, and demonstrate that rearrangements in this region are associated with behavioral and neurodevelopmental abnormalities, including cognitive impairment, autism, hyperactivity, and possibly psychiatric disease. Fine mapping of the deletions in members of all three families by use of a custom 10q oligonucleotide array-based comparative genomic hybridization (NimbleGen) and polymerase chain reaction-based methods demonstrated a different deletion in each family. In one proband, the deletion breakpoints are associated with DNA fragments containing noncontiguous sequences of chromosome 10, whereas, in the other two families, the breakpoints are within paralogous LCRs, removing approximately 7.2 Mb and 32 genes. Our data provide evidence that the 10q22-q23 genomic region harbors one or more genes important for cognitive and behavioral development and that recurrent deletions affecting this interval define a novel genomic disorder.
