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Sample records for spotted cdna microarrays

  1. Use of cDNA microarray to isolate differentially expressed genes in White Spot Virus infected shrimp (penaeus stylirostris)

    OpenAIRE

    Dhar, Arun K.; Klimpel, Kurt R.; Bullis, Robert A.; McClenaghan, Leroy R.

    2006-01-01

    White spot syndrome virus (WSSV), the etiologic agent of white spot disease, is currently the most important viral pathogen infecting penaeid shrimp worldwide. Since the initial report, white spot disease has caused losses of catastrophic proportion to shrimp aquaculture globally. Although considerable progress has been made in characterizing the WSSV and developing detection methods, information on the host genes involved in the immune response in shrimp due to WSSV infection is not availabl...

  2. AN IMPROVED FUZZY CLUSTERING ALGORITHM FOR MICROARRAY IMAGE SPOTS SEGMENTATION

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    V.G. Biju

    2015-11-01

    Full Text Available An automatic cDNA microarray image processing using an improved fuzzy clustering algorithm is presented in this paper. The spot segmentation algorithm proposed uses the gridding technique developed by the authors earlier, for finding the co-ordinates of each spot in an image. Automatic cropping of spots from microarray image is done using these co-ordinates. The present paper proposes an improved fuzzy clustering algorithm Possibility fuzzy local information c means (PFLICM to segment the spot foreground (FG from background (BG. The PFLICM improves fuzzy local information c means (FLICM algorithm by incorporating typicality of a pixel along with gray level information and local spatial information. The performance of the algorithm is validated using a set of simulated cDNA microarray images added with different levels of AWGN noise. The strength of the algorithm is tested by computing the parameters such as the Segmentation matching factor (SMF, Probability of error (pe, Discrepancy distance (D and Normal mean square error (NMSE. SMF value obtained for PFLICM algorithm shows an improvement of 0.9 % and 0.7 % for high noise and low noise microarray images respectively compared to FLICM algorithm. The PFLICM algorithm is also applied on real microarray images and gene expression values are computed.

  3. A novel method using edge detection for signal extraction from cDNA microarray image analysis.

    Science.gov (United States)

    Kim, J H; Kim, H Y; Lee, Y S

    2001-06-30

    Gene expression analyses by probes of hybridization from mRNA to cDNA targets arrayed on membranes or activated glass surfaces have revolutionized the way of profiling mega level gene expression. The main remaining problems however are sensitivity of detection, reproducibility and data processing. During processing of microarray images, especially irregularities of spot position and shape could generate significant errors: small regions of signal spots can be mis-included into background area and vice versa. Here we report a novel method to eliminate such obstacles by sensing their edges. Application of edge detection technology on separating spots from the background decreases the probability of the errors and gives more accurate information about the states of spots such as the pixel number, degree of fragmentation, width and height of spot, and circumference of spot. Such information can be used for the quality control of cDNA microarray experiments and filtering of low quality spots. We analyzed the cDNA microarray image that contains 10,368 genes using edge detection and compared the result with that of conventional method which draws circle around the spot.

  4. Observation of intermittency in gene expression on cDNA microarrays

    CERN Document Server

    Peterson, L E

    2002-01-01

    We used scaled factorial moments to search for intermittency in the log expression ratios (LERs) for thousands of genes spotted on cDNA microarrays (gene chips). Results indicate varying levels of intermittency in gene expression. The observation of intermittency in the data analyzed provides a complimentary handle on moderately expressed genes, generally not tackled by conventional techniques.

  5. Screening of cDNA libraries on glass slide microarrays.

    Science.gov (United States)

    Berger, Dave K; Crampton, Bridget G; Hein, Ingo; Vos, Wiesner

    2007-01-01

    A quantitative screening method was developed to evaluate the quality of cDNA libraries constructed by suppression subtraction hybridization (SSH) or other enrichment techniques. The SSH technique was adapted to facilitate screening of the resultant library on a small number of glass slide microarrays. A simple data analysis pipeline named SSHscreen using "linear models for microarray data" (limma) functions in the R computing environment was developed to identify clones in the cDNA libraries that are significantly differentially expressed, and to determine if they were rare or abundant in the original treated sample. This approach facilitates the choice of clones from the cDNA library for further analysis, such as DNA sequencing, Northern blotting, RT-PCR, or detailed expression profiling using a custom cDNA microarray. Furthermore, this strategy is particularly useful for studies of nonmodel organisms for which there is little genome sequence information.

  6. A Combinational Clustering Based Method for cDNA Microarray Image Segmentation.

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    Guifang Shao

    Full Text Available Microarray technology plays an important role in drawing useful biological conclusions by analyzing thousands of gene expressions simultaneously. Especially, image analysis is a key step in microarray analysis and its accuracy strongly depends on segmentation. The pioneering works of clustering based segmentation have shown that k-means clustering algorithm and moving k-means clustering algorithm are two commonly used methods in microarray image processing. However, they usually face unsatisfactory results because the real microarray image contains noise, artifacts and spots that vary in size, shape and contrast. To improve the segmentation accuracy, in this article we present a combination clustering based segmentation approach that may be more reliable and able to segment spots automatically. First, this new method starts with a very simple but effective contrast enhancement operation to improve the image quality. Then, an automatic gridding based on the maximum between-class variance is applied to separate the spots into independent areas. Next, among each spot region, the moving k-means clustering is first conducted to separate the spot from background and then the k-means clustering algorithms are combined for those spots failing to obtain the entire boundary. Finally, a refinement step is used to replace the false segmentation and the inseparable ones of missing spots. In addition, quantitative comparisons between the improved method and the other four segmentation algorithms--edge detection, thresholding, k-means clustering and moving k-means clustering--are carried out on cDNA microarray images from six different data sets. Experiments on six different data sets, 1 Stanford Microarray Database (SMD, 2 Gene Expression Omnibus (GEO, 3 Baylor College of Medicine (BCM, 4 Swiss Institute of Bioinformatics (SIB, 5 Joe DeRisi's individual tiff files (DeRisi, and 6 University of California, San Francisco (UCSF, indicate that the improved

  7. A Combinational Clustering Based Method for cDNA Microarray Image Segmentation.

    Science.gov (United States)

    Shao, Guifang; Li, Tiejun; Zuo, Wangda; Wu, Shunxiang; Liu, Tundong

    2015-01-01

    Microarray technology plays an important role in drawing useful biological conclusions by analyzing thousands of gene expressions simultaneously. Especially, image analysis is a key step in microarray analysis and its accuracy strongly depends on segmentation. The pioneering works of clustering based segmentation have shown that k-means clustering algorithm and moving k-means clustering algorithm are two commonly used methods in microarray image processing. However, they usually face unsatisfactory results because the real microarray image contains noise, artifacts and spots that vary in size, shape and contrast. To improve the segmentation accuracy, in this article we present a combination clustering based segmentation approach that may be more reliable and able to segment spots automatically. First, this new method starts with a very simple but effective contrast enhancement operation to improve the image quality. Then, an automatic gridding based on the maximum between-class variance is applied to separate the spots into independent areas. Next, among each spot region, the moving k-means clustering is first conducted to separate the spot from background and then the k-means clustering algorithms are combined for those spots failing to obtain the entire boundary. Finally, a refinement step is used to replace the false segmentation and the inseparable ones of missing spots. In addition, quantitative comparisons between the improved method and the other four segmentation algorithms--edge detection, thresholding, k-means clustering and moving k-means clustering--are carried out on cDNA microarray images from six different data sets. Experiments on six different data sets, 1) Stanford Microarray Database (SMD), 2) Gene Expression Omnibus (GEO), 3) Baylor College of Medicine (BCM), 4) Swiss Institute of Bioinformatics (SIB), 5) Joe DeRisi's individual tiff files (DeRisi), and 6) University of California, San Francisco (UCSF), indicate that the improved approach is

  8. [Software development in data analysis and mining for cDNA microarray].

    Science.gov (United States)

    Wu, Bin; Wang, Jianguo; Wang, Miqu

    2007-12-01

    Data analysis and mining is a key issue to microarray technology and is usually implemented through software development. This paper summarizes the state-of-art software development in cDNA microarray data analysis and mining. The updated software developments are discussed in three stages: data inquisition from cDNA microarray tests, statistical treatment of cDNA data and data mining from gene network.

  9. Advanced spot quality analysis in two-colour microarray experiments

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    Vetter Guillaume

    2008-09-01

    Full Text Available Abstract Background Image analysis of microarrays and, in particular, spot quantification and spot quality control, is one of the most important steps in statistical analysis of microarray data. Recent methods of spot quality control are still in early age of development, often leading to underestimation of true positive microarray features and, consequently, to loss of important biological information. Therefore, improving and standardizing the statistical approaches of spot quality control are essential to facilitate the overall analysis of microarray data and subsequent extraction of biological information. Findings We evaluated the performance of two image analysis packages MAIA and GenePix (GP using two complementary experimental approaches with a focus on the statistical analysis of spot quality factors. First, we developed control microarrays with a priori known fluorescence ratios to verify the accuracy and precision of the ratio estimation of signal intensities. Next, we developed advanced semi-automatic protocols of spot quality evaluation in MAIA and GP and compared their performance with available facilities of spot quantitative filtering in GP. We evaluated these algorithms for standardised spot quality analysis in a whole-genome microarray experiment assessing well-characterised transcriptional modifications induced by the transcription regulator SNAI1. Using a set of RT-PCR or qRT-PCR validated microarray data, we found that the semi-automatic protocol of spot quality control we developed with MAIA allowed recovering approximately 13% more spots and 38% more differentially expressed genes (at FDR = 5% than GP with default spot filtering conditions. Conclusion Careful control of spot quality characteristics with advanced spot quality evaluation can significantly increase the amount of confident and accurate data resulting in more meaningful biological conclusions.

  10. Microarrays in ecological research: A case study of a cDNA microarray for plant-herbivore interactions

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    Gase Klaus

    2004-09-01

    Full Text Available Abstract Background Microarray technology allows researchers to simultaneously monitor changes in the expression ratios (ERs of hundreds of genes and has thereby revolutionized most of biology. Although this technique has the potential of elucidating early stages in an organism's phenotypic response to complex ecological interactions, to date, it has not been fully incorporated into ecological research. This is partially due to a lack of simple procedures of handling and analyzing the expression ratio (ER data produced from microarrays. Results We describe an analysis of the sources of variation in ERs from 73 hybridized cDNA microarrays, each with 234 herbivory-elicited genes from the model ecological expression system, Nicotiana attenuata, using procedures that are commonly used in ecologic research. Each gene is represented by two independently labeled PCR products and each product was arrayed in quadruplicate. We present a robust method of normalizing and analyzing ERs based on arbitrary thresholds and statistical criteria, and characterize a "norm of reaction" of ERs for 6 genes (4 of known function, 2 of unknown with different ERs as determined across all analyzed arrays to provide a biologically-informed alternative to the use of arbitrary expression ratios in determining significance of expression. These gene-specific ERs and their variance (gene CV were used to calculate array-based variances (array CV, which, in turn, were used to study the effects of array age, probe cDNA quantity and quality, and quality of spotted PCR products as estimates of technical variation. Cluster analysis and a Principal Component Analysis (PCA were used to reveal associations among the transcriptional "imprints" of arrays hybridized with cDNA probes derived from mRNA from N. attenuata plants variously elicited and attacked by different herbivore species and from three congeners: N. quadrivalis, N. longiflora and N. clevelandii. Additionally, the PCA

  11. Radioactive cDNA microarray (II): Gene expression profiling of antidepressant treatment by human cDNA microarray

    International Nuclear Information System (INIS)

    Lee, Ji Hye; Kang, Rhee Hun; Ham, Byung Joo; Lee, Min Su; Shin, Kyung Ho; Choe, Jae Gol; Kim, Meyoung Kon

    2003-01-01

    Major depressive disorder is a prevalent psychiatric disorder in primary care, associated with impaired patient functioning and well-being. Fluoxetine is a selective serotonin-reuptake inhibitors (SSRIs) and is a commonly prescribed antidepressant compound. Its action is primarily attributed to selective inhibition of the reuptake of serotonin (5-hydroxytryptamine) in the central nervous system. Objectives ; the aims of this study were two-fold: (1) to determine the usefulness for investigation of the transcription profiles in depression patients, and (2) to assess the differences in gene expression profiles between positive response group and negative response groups by fluoxetine treatment. This study included 53 patients with major depression (26 in positive response group with antidepressant treatment, 27 in negative response group with antidepressant treatment), and 53 healthy controls. To examine the difference of gene expression profile in depression patients, radioactive complementary DNA microarrays were used to evaluate changes in the expression of 1,152 genes in total. Using 33p-labeled probes, this method provided highly sensitive gene expression profiles including brain receptors, drug metabolism, and cellular signaling. Gene transcription profiles were classified into several categories in accordance with the antidepressant gene-regulation. The gene profiles were significantly up-(22 genes) and down-(16 genes) regulated in the positive response group when compared to the control group. Also, in the negative response group, 35 genes were up-regulated and 8 genes were down-regulated when compared to the control group. Consequently, we demonstrated that radioactive human cDNA microarray is highly likely to be an efficient technology for evaluating the gene regulation of antidepressants, such as selective serotonin-reuptake inhibitors (SSRIs), by using high-throughput biotechnology

  12. Radioactive cDNA microarray (II): Gene expression profiling of antidepressant treatment by human cDNA microarray

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    Lee, Ji Hye; Kang, Rhee Hun; Ham, Byung Joo; Lee, Min Su; Shin, Kyung Ho; Choe, Jae Gol; Kim, Meyoung Kon [College of Medicine, Univ. of Korea, Seoul (Korea, Republic of)

    2003-07-01

    Major depressive disorder is a prevalent psychiatric disorder in primary care, associated with impaired patient functioning and well-being. Fluoxetine is a selective serotonin-reuptake inhibitors (SSRIs) and is a commonly prescribed antidepressant compound. Its action is primarily attributed to selective inhibition of the reuptake of serotonin (5-hydroxytryptamine) in the central nervous system. Objectives ; the aims of this study were two-fold: (1) to determine the usefulness for investigation of the transcription profiles in depression patients, and (2) to assess the differences in gene expression profiles between positive response group and negative response groups by fluoxetine treatment. This study included 53 patients with major depression (26 in positive response group with antidepressant treatment, 27 in negative response group with antidepressant treatment), and 53 healthy controls. To examine the difference of gene expression profile in depression patients, radioactive complementary DNA microarrays were used to evaluate changes in the expression of 1,152 genes in total. Using 33p-labeled probes, this method provided highly sensitive gene expression profiles including brain receptors, drug metabolism, and cellular signaling. Gene transcription profiles were classified into several categories in accordance with the antidepressant gene-regulation. The gene profiles were significantly up-(22 genes) and down-(16 genes) regulated in the positive response group when compared to the control group. Also, in the negative response group, 35 genes were up-regulated and 8 genes were down-regulated when compared to the control group. Consequently, we demonstrated that radioactive human cDNA microarray is highly likely to be an efficient technology for evaluating the gene regulation of antidepressants, such as selective serotonin-reuptake inhibitors (SSRIs), by using high-throughput biotechnology.

  13. Spotted cotton oligonucleotide microarrays for gene expression analysis

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    Nettleton Dan

    2007-03-01

    Full Text Available Abstract Background Microarrays offer a powerful tool for diverse applications plant biology and crop improvement. Recently, two comprehensive assemblies of cotton ESTs were constructed based on three Gossypium species. Using these assemblies as templates, we describe the design and creation and of a publicly available oligonucleotide array for cotton, useful for all four of the cultivated species. Results Synthetic oligonucleotide probes were generated from exemplar sequences of a global assembly of 211,397 cotton ESTs derived from >50 different cDNA libraries representing many different tissue types and tissue treatments. A total of 22,787 oligonucleotide probes are included on the arrays, optimized to target the diversity of the transcriptome and previously studied cotton genes, transcription factors, and genes with homology to Arabidopsis. A small portion of the oligonucleotides target unidentified protein coding sequences, thereby providing an element of gene discovery. Because many oligonucleotides were based on ESTs from fiber-specific cDNA libraries, the microarray has direct application for analysis of the fiber transcriptome. To illustrate the utility of the microarray, we hybridized labeled bud and leaf cDNAs from G. hirsutum and demonstrate technical consistency of results. Conclusion The cotton oligonucleotide microarray provides a reproducible platform for transcription profiling in cotton, and is made publicly available through http://cottonevolution.info.

  14. GENE EXPRESSION IN THE TESTES OF NORMOSPERMIC VERSUS TERATOSPERMIC DOMESTIC CATS USING HUMAN CDNA MICROARRAY ANALYSES

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    GENE EXPRESSION IN THE TESTES OF NORMOSPERMIC VERSUS TERATOSPERMIC DOMESTIC CATS USING HUMAN cDNA MICROARRAY ANALYSESB.S. Pukazhenthi1, J. C. Rockett2, M. Ouyang3, D.J. Dix2, J.G. Howard1, P. Georgopoulos4, W.J. J. Welsh3 and D. E. Wildt11Department of Reproductiv...

  15. ESTs, cDNA microarrays, and gene expression profiling: tools for dissecting plant physiology and development.

    Science.gov (United States)

    Alba, Rob; Fei, Zhangjun; Payton, Paxton; Liu, Yang; Moore, Shanna L; Debbie, Paul; Cohn, Jonathan; D'Ascenzo, Mark; Gordon, Jeffrey S; Rose, Jocelyn K C; Martin, Gregory; Tanksley, Steven D; Bouzayen, Mondher; Jahn, Molly M; Giovannoni, Jim

    2004-09-01

    Gene expression profiling holds tremendous promise for dissecting the regulatory mechanisms and transcriptional networks that underlie biological processes. Here we provide details of approaches used by others and ourselves for gene expression profiling in plants with emphasis on cDNA microarrays and discussion of both experimental design and downstream analysis. We focus on methods and techniques emphasizing fabrication of cDNA microarrays, fluorescent labeling, cDNA hybridization, experimental design, and data processing. We include specific examples that demonstrate how this technology can be used to further our understanding of plant physiology and development (specifically fruit development and ripening) and for comparative genomics by comparing transcriptome activity in tomato and pepper fruit.

  16. Screening for candidate genes related to breast cancer with cDNA microarray analysis

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    Yu-Juan Xiang

    2015-06-01

    Full Text Available Objective: The aim of this study was to reveal the exact changes during the occurrence of breast cancer to explore significant new and promising genes or factors related to this disease. Methods: We compared the gene expression profiles of breast cancer tissues with its uninvolved normal breast tissues as controls using the cDNA microarray analysis in seven breast cancer patients. Further, one representative gene, named IFI30, was quantitatively analyzed by real-time PCR to confirm the result of the cDNA microarray analysis. Results: A total of 427 genes were identified with significantly differential expression, 221 genes were up-regulated and 206 genes were down-regulated. And the result of cDNA microarray analysis was validated by detection of IFI30 mRNA level changes by real-time PCR. Genes for cell proliferation, cell cycle, cell division, mitosis, apoptosis, and immune response were enriched in the up-regulated genes, while genes for cell adhesion, proteolysis, and transport were significantly enriched in the down-regulated genes in breast cancer tissues compared with normal breast tissues by a gene ontology analysis. Conclusion: Our present study revealed a range of differentially expressed genes between breast cancer tissues and normal breast tissues, and provide candidate genes for further study focusing on the pathogenesis and new biomarkers for breast cancer. Keywords: Breast neoplasms, Candidate genes, Microarray

  17. Chromosomal Localization of DNA Amplifications in Neuroblastoma Tumors Using cDNA Microarray Comparative Genomic Hybridization

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    Ben Beheshti

    2003-01-01

    Full Text Available Conventional comparative genomic hybridization (CGH profiling of neuroblastomas has identified many genomic aberrations, although the limited resolution has precluded a precise localization of sequences of interest within amplicons. To map high copy number genomic gains in clinically matched stage IV neuroblastomas, CGH analysis using a 19,200-feature cDNA microarray was used. A dedicated (freely available algorithm was developed for rapid in silico determination of chromosomal localizations of microarray cDNA targets, and for generation of an ideogram-type profile of copy number changes. Using these methodologies, novel gene amplifications undetectable by chromosome CGH were identified, and larger MYCN amplicon sizes (in one tumor up to 6 Mb than those previously reported in neuroblastoma were identified. The genes HPCAL1, LPIN1/KIAA0188, NAG, and NSE1/LOC151354 were found to be coamplified with MYCN. To determine whether stage IV primary tumors could be further subclassified based on their genomic copy number profiles, hierarchical clustering was performed. Cluster analysis of microarray CGH data identified three groups: 1 no amplifications evident, 2 a small MYCN amplicon as the only detectable imbalance, and 3 a large MYCN amplicon with additional gene amplifications. Application of CGH to cDNA microarray targets will help to determine both the variation of amplicon size and help better define amplification-dependent and independent pathways of progression in neuroblastoma.

  18. [Combining SSH and cDNA microarray for identification of lung cancer related genes].

    Science.gov (United States)

    Fan, Baoxing; Zhang, Kaitai; Da, Jiping; Xie, Ling; Wang, Shengqi; Wu, Dechang

    2003-04-20

    To screen and identify differentially expressed genes among lung cancer tissues, paracancerous pulmonary tissues and some other kinds of tumor tissues using suppression subtractive hybridization (SSH) and cDNA Microarray. One cDNA chip was made by gathering clones of three differentially expressed cDNA libraries which came from BEP2D cell lines during three different malignant transformed phases. Then the clones were hybridizated with cDNA probes which extracted from 15 cases of lung cancer tissues, 5 cases of paracancerous pulmonary tissues and 24 cases of other 8 kinds of tumor tissues respectively. Twenty-six cDNAs were obtained which expressed higher in lung cancer tissues than that in paracancerous pulmonary tissues. Thirty-one cDNAs expressed remarkably higher in paracancerous tissues than those in cancer tissues. Compared with other 8 kinds of tumors, paracancerous tissues had 63 overexpressed cDNAs and lung cancer tissues had 87 overexpressed cDNAs. The combination of SSH and cDNA microarray is rapid and effective for screening and identification of differentially expressed genes in different samples. It may be potentially useful for diagnosis of lung cancer to further study the differentially expressed genes among lung cancer tissues, paracancerous pulmonary tissues and other tumor tissues.

  19. The effects of radiation on p53-mutated glioma cells using cDNA microarray technique

    International Nuclear Information System (INIS)

    Ngo, F.Q.H.; Hsiao, Y.-Y.H.

    2003-01-01

    Full text: In this study, we investigated the effects of 10-Gy irradiation on cell-cycle arrest, apoptosis and clonogenic death in the p53-mutated human U138MG (malignant glioblastoma) cell line. In order to evaluate time-dependent events in cellular responses to radiation, we did a time course study by incubating cells ranging from 0.5 to 48 hours after irradiation. Cell-cycle distribution and apoptosis were evaluated by flow cytometry using propidium iodide (PI) and annexin-V plus PI staining. Cell viability and proliferative capacity were studied by colony formation assay. Dual fluorescence cDNA microarray technique was used to examine the differential expression patterns of the irradiated cells. The cDNA microarray chips used contained DNA sequences corresponding to 12,814 human genes. From the flow cytometry data, it can be observed that radiation induced G2/M phase arrest and that late apoptosis was more evident following G2/M arrest. After 36 hours, some cells underwent senescence and the remains continued on with the cell cycle. Microarray analyses revealed changes in the expression of a small number of cell-cycle-related genes (p21, cyclin B1, etc.) and cell-death genes (tumor necrosis factors, DDB2, etc.) suggesting their involvement in radiation-induced cell-cycle arrest and apoptosis. In silico interpretations of the molecular mechanisms responsible for these radiation effects are in progress

  20. Gene expression profile analysis in human hepatocellular carcinoma by cDNA microarray.

    Science.gov (United States)

    Chung, Eun Jung; Sung, Young Kwan; Farooq, Mohammad; Kim, Younghee; Im, Sanguk; Tak, Won Young; Hwang, Yoon Jin; Kim, Yang Il; Han, Hyung Soo; Kim, Jung-Chul; Kim, Moon Kyu

    2002-12-31

    We performed gene expression profiling of normal and hepatocellular carcinoma (HCC) liver tissues using a high-density microarray that contained 3,063 human cDNA. The results of a microarray hybridization experiment from eight different HCC tissues were analyzed and classified by the Cluster program. Among these differentially-expressed genes, the galectin-3, serine/threonine kinase SGK, translation factor eIF-4A, -4B, -3, fibroblast growth factor receptor, and ribosomal protein L35A were up-regulated; the mRNAs of Nip3, decorin, and the insulin-like growth factor binding protein-3 were down-regulated in HCC. The differential expression of these genes was further confirmed by an RT-PCR analysis. In addition, our data suggest that the gene expression profile of HCC varies according to the histological types.

  1. A cell spot microarray method for production of high density siRNA transfection microarrays

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    Mpindi John-Patrick

    2011-03-01

    Full Text Available Abstract Background High-throughput RNAi screening is widely applied in biological research, but remains expensive, infrastructure-intensive and conversion of many assays to HTS applications in microplate format is not feasible. Results Here, we describe the optimization of a miniaturized cell spot microarray (CSMA method, which facilitates utilization of the transfection microarray technique for disparate RNAi analyses. To promote rapid adaptation of the method, the concept has been tested with a panel of 92 adherent cell types, including primary human cells. We demonstrate the method in the systematic screening of 492 GPCR coding genes for impact on growth and survival of cultured human prostate cancer cells. Conclusions The CSMA method facilitates reproducible preparation of highly parallel cell microarrays for large-scale gene knockdown analyses. This will be critical towards expanding the cell based functional genetic screens to include more RNAi constructs, allow combinatorial RNAi analyses, multi-parametric phenotypic readouts or comparative analysis of many different cell types.

  2. Evaluation of the gene-specific dye bias in cDNA microarray experiments.

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    Martin-Magniette, Marie-Laure; Aubert, Julie; Cabannes, Eric; Daudin, Jean-Jacques

    2005-05-01

    In cDNA microarray experiments all samples are labeled with either Cy3 or Cy5. Systematic and gene-specific dye bias effects have been observed in dual-color experiments. In contrast to systematic effects which can be corrected by a normalization method, the gene-specific dye bias is not completely suppressed and may alter the conclusions about the differentially expressed genes. The gene-specific dye bias is taken into account using an analysis of variance model. We propose an index, named label bias index, to measure the gene-specific dye bias. It requires at least two self-self hybridization cDNA microarrays. After lowess normalization we have found that the gene-specific dye bias is the major source of experimental variability between replicates. The ratio (R/G) may exceed 2. As a consequence false positive genes may be found in direct comparison without dye-swap. The stability of this artifact and its consequences on gene variance and on direct or indirect comparisons are addressed. http://www.inapg.inra.fr/ens_rech/mathinfo/recherche/mathematique

  3. Development of a porcine skeletal muscle cDNA microarray: analysis of differential transcript expression in phenotypically distinct muscles

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    Stear Michael

    2003-03-01

    Full Text Available Abstract Background Microarray profiling has the potential to illuminate the molecular processes that govern the phenotypic characteristics of porcine skeletal muscles, such as hypertrophy or atrophy, and the expression of specific fibre types. This information is not only important for understanding basic muscle biology but also provides underpinning knowledge for enhancing the efficiency of livestock production. Results We report on the de novo development of a composite skeletal muscle cDNA microarray, comprising 5500 clones from two developmentally distinct cDNA libraries (longissimus dorsi of a 50-day porcine foetus and the gastrocnemius of a 3-day-old pig. Clones selected for the microarray assembly were of low to moderate abundance, as indicated by colony hybridisation. We profiled the differential expression of genes between the psoas (red muscle and the longissimus dorsi (white muscle, by co-hybridisation of Cy3 and Cy5 labelled cDNA derived from these two muscles. Results from seven microarray slides (replicates correctly identified genes that were expected to be differentially expressed, as well as a number of novel candidate regulatory genes. Quantitative real-time RT-PCR on selected genes was used to confirm the results from the microarray. Conclusion We have developed a porcine skeletal muscle cDNA microarray and have identified a number of candidate genes that could be involved in muscle phenotype determination, including several members of the casein kinase 2 signalling pathway.

  4. Evaluation of normalization methods for cDNA microarray data by k-NN classification

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    Wu, Wei; Xing, Eric P; Myers, Connie; Mian, Saira; Bissell, Mina J

    2004-12-17

    Non-biological factors give rise to unwanted variations in cDNA microarray data. There are many normalization methods designed to remove such variations. However, to date there have been few published systematic evaluations of these techniques for removing variations arising from dye biases in the context of downstream, higher-order analytical tasks such as classification. Ten location normalization methods that adjust spatial- and/or intensity-dependent dye biases, and three scale methods that adjust scale differences were applied, individually and in combination, to five distinct, published, cancer biology-related cDNA microarray data sets. Leave-one-out cross-validation (LOOCV) classification error was employed as the quantitative end-point for assessing the effectiveness of a normalization method. In particular, a known classifier, k-nearest neighbor (k-NN), was estimated from data normalized using a given technique, and the LOOCV error rate of the ensuing model was computed. We found that k-NN classifiers are sensitive to dye biases in the data. Using NONRM and GMEDIAN as baseline methods, our results show that single-bias-removal techniques which remove either spatial-dependent dye bias (referred later as spatial effect) or intensity-dependent dye bias (referred later as intensity effect) moderately reduce LOOCV classification errors; whereas double-bias-removal techniques which remove both spatial- and intensity effect reduce LOOCV classification errors even further. Of the 41 different strategies examined, three two-step processes, IGLOESS-SLFILTERW7, ISTSPLINE-SLLOESS and IGLOESS-SLLOESS, all of which removed intensity effect globally and spatial effect locally, appear to reduce LOOCV classification errors most consistently and effectively across all data sets. We also found that the investigated scale normalization methods do not reduce LOOCV classification error. Using LOOCV error of k-NNs as the evaluation criterion, three double

  5. Genes expression by using cDNA Microarray in Whallak-tang

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    Cheol-kyung Sin

    2008-12-01

    Full Text Available Objective : This study was undertaken to determine the effect of Whallak-tang on expression of CD/cytokine Genes. Methods : The expression of CD/Cytokine Genes were examined by cDNA microarray using the human mast cell line(HMC-l. Results : The expression of ATP5F1, FLJ20671, unknown, KIAA0342, OAS2, unknown genes were increased in 200~300% range. The expression of unknown, MDS006, IFITM1, MRPL3, ZNF207, FTH1, FBP1, NRGN, NR1H2, KIAA0747 genes were decreased in 0~33% range. Conclusion : These results would provide important basic data on the possibility of the clinical treatment of Whallaktang in musculoskeletal disease.

  6. A comparison of parametric and nonparametric methods for normalising cDNA microarray data.

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    Khondoker, Mizanur R; Glasbey, Chris A; Worton, Bruce J

    2007-12-01

    Normalisation is an essential first step in the analysis of most cDNA microarray data, to correct for effects arising from imperfections in the technology. Loess smoothing is commonly used to correct for trends in log-ratio data. However, parametric models, such as the additive plus multiplicative variance model, have been preferred for scale normalisation, though the variance structure of microarray data may be of a more complex nature than can be accommodated by a parametric model. We propose a new nonparametric approach that incorporates location and scale normalisation simultaneously using a Generalised Additive Model for Location, Scale and Shape (GAMLSS, Rigby and Stasinopoulos, 2005, Applied Statistics, 54, 507-554). We compare its performance in inferring differential expression with Huber et al.'s (2002, Bioinformatics, 18, 96-104) arsinh variance stabilising transformation (AVST) using real and simulated data. We show GAMLSS to be as powerful as AVST when the parametric model is correct, and more powerful when the model is wrong. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  7. Normal uniform mixture differential gene expression detection for cDNA microarrays

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    Raftery Adrian E

    2005-07-01

    Full Text Available Abstract Background One of the primary tasks in analysing gene expression data is finding genes that are differentially expressed in different samples. Multiple testing issues due to the thousands of tests run make some of the more popular methods for doing this problematic. Results We propose a simple method, Normal Uniform Differential Gene Expression (NUDGE detection for finding differentially expressed genes in cDNA microarrays. The method uses a simple univariate normal-uniform mixture model, in combination with new normalization methods for spread as well as mean that extend the lowess normalization of Dudoit, Yang, Callow and Speed (2002 1. It takes account of multiple testing, and gives probabilities of differential expression as part of its output. It can be applied to either single-slide or replicated experiments, and it is very fast. Three datasets are analyzed using NUDGE, and the results are compared to those given by other popular methods: unadjusted and Bonferroni-adjusted t tests, Significance Analysis of Microarrays (SAM, and Empirical Bayes for microarrays (EBarrays with both Gamma-Gamma and Lognormal-Normal models. Conclusion The method gives a high probability of differential expression to genes known/suspected a priori to be differentially expressed and a low probability to the others. In terms of known false positives and false negatives, the method outperforms all multiple-replicate methods except for the Gamma-Gamma EBarrays method to which it offers comparable results with the added advantages of greater simplicity, speed, fewer assumptions and applicability to the single replicate case. An R package called nudge to implement the methods in this paper will be made available soon at http://www.bioconductor.org.

  8. An improved K-means clustering method for cDNA microarray image segmentation.

    Science.gov (United States)

    Wang, T N; Li, T J; Shao, G F; Wu, S X

    2015-07-14

    Microarray technology is a powerful tool for human genetic research and other biomedical applications. Numerous improvements to the standard K-means algorithm have been carried out to complete the image segmentation step. However, most of the previous studies classify the image into two clusters. In this paper, we propose a novel K-means algorithm, which first classifies the image into three clusters, and then one of the three clusters is divided as the background region and the other two clusters, as the foreground region. The proposed method was evaluated on six different data sets. The analyses of accuracy, efficiency, expression values, special gene spots, and noise images demonstrate the effectiveness of our method in improving the segmentation quality.

  9. Gene expression of panaxydol-treated human melanoma cells using radioactive cDNA microarrays

    International Nuclear Information System (INIS)

    Cho, Joong Youn; Yu, Su Jin; Soh, Jeong Won; Kim, Meyoung Kon

    2001-01-01

    Polyacetylenic alcohols derived from Panax ginseng have been studied to be an anticancer reagent previously. One of the Panax ginseng polyacetylenic alcohols, i.e., panaxydol, has been studied to possess an antiproliferative effect on human melanoma cell line (SK-MEL-1). In ths study, radioactive cDNA microarrays enabled an efficient approach to analyze the pattern of gene expression (3.194 genes in a total) simultaneously. The bioinformatics selection of human cDNAs, which is specifically designed for immunology, apoptosis and signal transduction, were arrayed on nylon membranes. Using with 33 P labeled probes, this method provided highly sensitive gene expression profiles of our interest including apoptosis, cell proliferation, cell cycle, and signal transduction. Gene expression profiles were also classified into several categories in accordance with the duration of panaxydol treatment. Consequently, the gene profiles of our interest were significantly up (199 genes, > 2.0 of Z-ratio) or down-(196 genes, < 2.0 of Z-ratio) regulated in panaxydol-treated human melanoma cells

  10. Comparative transcriptome maps: a new approach to the diagnosis of colorectal carcinoma patients using cDNA microarrays

    Czech Academy of Sciences Publication Activity Database

    Jansová, E.; Koutná, I.; Krontorád, P.; Svoboda, Z.; Křivánková, S.; Žaloudík, J.; Kozubek, M.; Kozubek, Stanislav

    2006-01-01

    Roč. 69, č. 3 (2006), s. 218-227 ISSN 0009-9163 R&D Projects: GA MZd(CZ) 1A8241; GA AV ČR(CZ) IAA5004306; GA AV ČR(CZ) IAA1065203; GA ČR(CZ) GA202/04/0907 Institutional research plan: CEZ:AV0Z50040507 Keywords : cDNA microarrays * colorectal carcinoma * expression profiles Subject RIV: BO - Biophysics Impact factor: 3.140, year: 2006

  11. Characterization of ovine hepatic gene expression profiles in response to Escherichia coli lipopolysaccharide using a bovine cDNA microarray

    Directory of Open Access Journals (Sweden)

    Boermans Herman J

    2006-11-01

    Full Text Available Abstract Background During systemic gram-negative bacterial infections, lipopolysaccharide (LPS ligation to the hepatic Toll-like receptor-4 complex induces the production of hepatic acute phase proteins that are involved in the host response to infection and limit the associated inflammatory process. Identifying the genes that regulate this hepatic response to LPS in ruminants may provide insight into the pathogenesis of bacterial diseases and eventually facilitate breeding of more disease resistant animals. The objective of this research was to profile the expression of ovine hepatic genes in response to Escherichia coli LPS challenge (0, 200, 400 ng/kg using a bovine cDNA microarray and quantitative real-time PCR (qRT-PCR. Results Twelve yearling ewes were challenged iv with E. coli LPS (0, 200, 400 ng/kg and liver biopsies were collected 4–5 hours post-challenge to assess hepatic gene expression profiles by bovine cDNA microarray and qRT-PCR analyses. The expression of CD14, C3, IL12R, NRAMP1, SOD and IGFBP3 genes was down regulated, whereas the expression of ACTHR, IFNαR, CD1, MCP-1 and GH was increased during LPS challenge. With the exception of C3, qRT-PCR analysis of 7 of these genes confirmed the microarray results and demonstrated that GAPDH is not a suitable housekeeping gene in LPS challenged sheep. Conclusion We have identified several potentially important genes by bovine cDNA microarray and qRT-PCR analyses that are differentially expressed during the ovine hepatic response to systemic LPS challenge. Their potential role in regulating the inflammatory response to LPS warrants further investigation.

  12. High resolution microarray comparative genomic hybridisation analysis using spotted oligonucleotides.

    NARCIS (Netherlands)

    Carvalho, B; Ouwerkerk, E; Meijer, G.A.; Ylstra, B.

    2004-01-01

    BACKGROUND: Currently, comparative genomic hybridisation array (array CGH) is the method of choice for studying genome wide DNA copy number changes. To date, either amplified representations of bacterial artificial chromosomes (BACs)/phage artificial chromosomes (PACs) or cDNAs have been spotted as

  13. Improving FoRe: A New Inlet Design for Filtering Samples through Individual Microarray Spots.

    Science.gov (United States)

    de Lange, Victoria; Habegger, Marco; Schmidt, Marco; Vörös, János

    2017-03-24

    In this publication we present an improvement to our previously introduced vertical flow microarray, the FoRe array, which capitalizes on the fusion of immunofiltration and densely packed micron test sites. Filtering samples through individual microarray spots allows us to rapidly analyze dilute samples with high-throughput and high signal-to-noise. Unlike other flowthrough microarrays, in the FoRe design samples are injected into micron channels and sequentially exposed to different targets. This arrangement makes it possible to increase the sensitivity of the microarray by simply increasing the sample volume or to rapidly reconcentrate samples after preprocessing steps dilute the analyte. Here we present a new inlet system which allows us to increase the analyzed sample volume without compromising the micron spot size and dense layout. We combined this with a model assay to demonstrate that the device is sensitive to the amount of antigen, and as a result, sample volume directly correlates to sensitivity. We introduced a simple technique for analysis of blood, which previously clogged the nanometer-sized pores, requiring only microliter volumes expected from an infant heel prick. A drop of blood is mixed with buffer to separate the plasma before reconcentrating the sample on the microarray spot. We demonstrated the success of this procedure by spiking TNF-α into blood and achieved a limit of detection of 18 pM. Compared to traditional protein microarrays, the FoRe array is still inexpensive, customizable, and simple to use, and thanks to these improvements has a broad range of applications from small animal studies to environmental monitoring.

  14. A computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

    Science.gov (United States)

    Zhang, Mingjun; Mao, Kaixuan; Tao, Weimin; Tarn, Tzyh-Jong

    2006-04-01

    Geometric measures (volume, area and length) of biological particles are of fundamental interest for biological studies. Many times, the measures are at micro-/nano-scale, and based on images of the biological particles. This paper proposes a computational method to geometric measure of biological particles. The method has been applied to DNA microarray spot size estimation. Compared with existing algorithms for microarray spot size estimation, the proposed method is computational efficient and also provides confidence probability on the measure. The contributions of this paper include a generic computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

  15. Detecting Outlier Microarray Arrays by Correlation and Percentage of Outliers Spots

    Directory of Open Access Journals (Sweden)

    Song Yang

    2006-01-01

    Full Text Available We developed a quality assurance (QA tool, namely microarray outlier filter (MOF, and have applied it to our microarray datasets for the identification of problematic arrays. Our approach is based on the comparison of the arrays using the correlation coefficient and the number of outlier spots generated on each array to reveal outlier arrays. For a human universal reference (HUR dataset, which is used as a technical control in our standard hybridization procedure, 3 outlier arrays were identified out of 35 experiments. For a human blood dataset, 12 outlier arrays were identified from 185 experiments. In general, arrays from human blood samples displayed greater variation in their gene expression profiles than arrays from HUR samples. As a result, MOF identified two distinct patterns in the occurrence of outlier arrays. These results demonstrate that this methodology is a valuable QA practice to identify questionable microarray data prior to downstream analysis.

  16. Use of the cDNA microarray technology in thesafety assessment of GM food plants

    DEFF Research Database (Denmark)

    Pedersen, Jan W.; Knudsen, Ib; Eriksen, Folmer Damsted

    This report focuses on new analytical approaches that might give more insight into possible changes in a genetically modified plant. Primarily the focus is on the new DNA microarray technique but also proteomics and metabolomics are discussed.The report describes the new techniques and evaluates ...

  17. Optical and surface analysis of DNA microarrays to assess printed spot heterogeneity

    Science.gov (United States)

    Nagaraja Rao, Archana

    DNA microarrays have been plagued with analytical problems with quantitation, metrics, figures of merit, and reliability and reproducibility issues, hindering their acceptance in clinical and diagnostic settings. The main deficiency in the printed DNA format is the microspot heterogeneity occurring during array fabrication and further amplified during target hybridization. Work described in this dissertation focuses on assessment of DNA microarray spots generated with conventional pin-type contact printing of fluorescently labeled DNA probes, on industry-standard commercial polymer-coated array slides and their hybridization with complementary oligomer DNA target. Printing of probe DNA microspots shares many features of commonly reported droplet evaporation dynamics that lead to different drying patterns and spot morphologies. This study directly identifies and analyzes different DNA probe chemical and spatial microenvironments within spots, analyzed with high-resolution time-of-flight secondary ion mass spectrometry (TOF-SIMS) chemical imaging, confocal epifluorescence, and probe microscopy force imaging methods. Drying of DNA probe spots shows Marangoni flow effects with high densities of probe DNA-Cy3 located in spot centers and nonhomogeneous DNA distributed radially within printed spots with both TOF-SIMS imaging and epifluorescence microscopy. Target hybridization kinetics and duplex formation were assessed using real-time in situ confocal imaging, and confirmed radial hemispherical diffusion-mediated distribution of target capture from spot edge to its interior. Kinetic modeling indicates pseudo-first order kinetics due to transport limitations and local density-dependent probe interactions with diffusing target. Fluorescence resonance energy transfer (FRET) and photobleaching results show that the high- density probe overcrowding in spots facilitates a broad range of target binding interactions regardless of dye orientations. Moreover, lateral probe density

  18. Genomics of hepatitis B virus-related hepatocellular carcinoma and adjacent noncancerous tissues with cDNA microarray.

    Science.gov (United States)

    Huang, Yu-kun; Fan, Xue-gong; Qiu, Fu; Wang, Zhi-ming

    2011-07-05

    Hepatocellular carcinoma (HCC) is a common primary cancer frequently associated with hepatitis B virus (HBV) infection. However, whether these identified genes are particularly associated with HBV-related HCC remains unknown. The aim of this study was to investigate the differential gene expression between HBV-related HCC tissues and adjacent noncancerous tissues. cDNA microarray was used to detect the differential gene expression profile in the HBV-related HCC tissues and adjacent noncancerous tissues, and reverse transcription-polymerase chain reaction (RT-PCR) was performed to verify the differential expression of candidate genes obtained from cDNA microarray experiment. In this study, 1369 genes or expressed sequence tags (ESTs) including 121 genes or ESTs with at least two-fold expression alterations between cancerous and noncancerous tissues were identified. Special AT-rich sequence binding protein 1 (SATB-1) expression was positive in 73% (16/22) of cancerous tissues and negative (0/22) in all noncancerous tissues of HBV-related HCC patients. Transmembrane 4 superfamily member 1 (TM4SF-1) expression was positive in 86% (19/22) of cancerous tissues and negative (0/22) in all noncancerous tissues. Suppression of tumorigenicity 14 (ST-14) expression was positive in 73% (16/22) of noncancerous tissues in patients with HBV-related HCC and negative in all HCC tissues (0/22). This study provided the gene expression profile of HBV-related HCC and presented differential expression patterns of SATB-1, TM4SF-1 and ST-14 between cancerous and noncancerous tissues in patients with HBV-related HCC.

  19. Development of a cDNA microarray for the measurement of gene expression in the sheep scab mite Psoroptes ovis

    Directory of Open Access Journals (Sweden)

    Burgess Stewart TG

    2012-02-01

    Full Text Available Abstract Background Sheep scab is caused by the ectoparasitic mite Psoroptes ovis which initiates a profound cutaneous inflammatory response, leading to the development of the skin lesions which are characteristic of the disease. Existing control strategies rely upon injectable endectocides and acaricidal dips but concerns over residues, eco-toxicity and the development of acaricide resistance limit the sustainability of this approach. In order to identify alternative means of disease control, a deeper understanding of both the parasite and its interaction with the host are required. Methods Herein we describe the development and utilisation of an annotated P. ovis cDNA microarray containing 3,456 elements for the measurement of gene expression in this economically important ectoparasite. The array consists of 981 P. ovis EST sequences printed in triplicate along with 513 control elements. Array performance was validated through the analysis of gene expression differences between fed and starved P. ovis mites. Results Sequences represented on the array include homologues of major house dust mite allergens and tick salivary proteins, along with factors potentially involved in mite reproduction and xenobiotic metabolism. In order to validate the performance of this unique resource under biological conditions we used the array to analyse gene expression differences between fed and starved P. ovis mites. These analyses identified a number of house dust mite allergen homologues up-regulated in fed mites and P. ovis transcripts involved in stress responses, autophagy and chemosensory perception up-regulated in starved mites. Conclusion The P. ovis cDNA microarray described here has been shown to be both robust and reproducible and will enable future studies to analyse gene expression in this important ectoparasite.

  20. High-throughput screening of suppression subtractive hybridization cDNA libraries using DNA microarray analysis.

    Science.gov (United States)

    van den Berg, Noëlani; Crampton, Bridget G; Hein, Ingo; Birch, Paul R J; Berger, Dave K

    2004-11-01

    Efficient construction of cDNA libraries enriched for differentially expressed transcripts is an important first step in many biological investigations. We present a quantitative procedure for screening cDNA libraries constructed by suppression subtractive hybridization (SSH). The methodology was applied to two independent SSHs from pearl millet and banana. Following two-color cyanin dye labeling and hybridization of subtracted tester with either unsubtracted driver or unsubtracted tester cDNAs to the SSH libraries arrayed on glass slides, two values were calculated for each clone, an enrichment ratio 1 (ER1) and an enrichment ratio 2 (ER2). Graphical representation of ER1 and ER2 enabled the identification of clones that were likely to represent up-regulated transcripts. Normalization of each clone by the SSH process was determined from the ER2 values, thereby indicating whether clones represented rare or abundant transcripts. Differential expression of pearl millet and banana clones identified from both libraries by this quantitative approach was verified by inverse Northern blot analysis.

  1. Tissue-wide expression profiling using cDNA subtraction and microarrays to identify tumor-specific genes.

    Science.gov (United States)

    Amatschek, Stefan; Koenig, Ulrich; Auer, Herbert; Steinlein, Peter; Pacher, Margit; Gruenfelder, Agnes; Dekan, Gerhard; Vogl, Sonja; Kubista, Ernst; Heider, Karl-Heinz; Stratowa, Christian; Schreiber, Martin; Sommergruber, Wolfgang

    2004-02-01

    With the objective of discovering novel putative intervention sites for anticancer therapy, we compared transcriptional profiles of breast cancer, lung squamous cell cancer (LSCC), lung adenocarcinoma (LAC), and renal cell cancer (RCC). Each of these tumor types still needs improvement in medical treatment. Our intention was to search for genes not only highly expressed in the majority of patient samples but which also exhibit very low or even absence of expression in a comprehensive panel of 16 critical (vital) normal tissues. To achieve this goal, we combined two powerful technologies, PCR-based cDNA subtraction and cDNA microarrays. Seven subtractive libraries consisting of approximately 9250 clones were established and enriched for tumor-specific transcripts. These clones, together with approximately 1750 additional tumor-relevant genes, were used for cDNA microarray preparation. Hybridizations were performed using a pool of 16 critical normal tissues as a reference in all experiments. In total, we analyzed 20 samples of breast cancer, 11 of LSCC, 11 of LAC, and 8 of RCC. To select for genes with low or even no expression in normal tissues, expression profiles of 22 different normal tissues were additionally analyzed. Importantly, this tissue-wide expression profiling allowed us to eliminate genes, which exhibit also high expression in normal tissues. Similarly, expression signatures of genes, which are derived from infiltrating cells of the immune system, were eliminated as well. Cluster analysis resulted in the identification of 527 expressed sequence tags specifically up-regulated in these tumors. Gene-wise hierarchical clustering of these clones clearly separated the different tumor types with RCC exhibiting the most homogeneous and LAC the most diverse expression profile. In addition to already known tumor-associated genes, the majority of identified genes have not yet been brought into context with tumorigenesis such as genes involved in bone matrix

  2. cDNA Microarray Analysis of Serially Sampled Cervical Cancer Specimens From Patients Treated With Thermochemoradiotherapy

    International Nuclear Information System (INIS)

    Borkamo, Erling Dahl; Schem, Baard-Christian; Fluge, Oystein; Bruland, Ove; Dahl, Olav; Mella, Olav

    2009-01-01

    Purpose: To elucidate changes in gene expression after treatment with regional thermochemoradiotherapy in locally advanced squamous cell cervical cancer. Methods and Materials: Tru-Cut biopsy specimens were serially collected from 16 patients. Microarray gene expression levels before and 24 h after the first and second trimodality treatment sessions were compared. Pathway and network analyses were conducted by use of Ingenuity Pathways Analysis (IPA; Ingenuity Systems, Redwood City, CA). Single gene expressions were analyzed by quantitative real-time reverse transcription-polymerase chain reaction. Results: We detected 53 annotated genes that were differentially expressed after trimodality treatment. Central in the three top networks detected by IPA were interferon alfa, interferon beta, and interferon gamma receptor; nuclear factor κB; and tumor necrosis factor, respectively. These genes encode proteins that are important in regulation cell signaling, proliferation, gene expression, and immune stimulation. Biological processes over-represented among the 53 genes were fibrosis, tumorigenesis, and immune response. Conclusions: Microarrays showed minor changes in gene expression after thermochemoradiotherapy in locally advanced cervical cancer. We detected 53 differentially expressed genes, mainly involved in fibrosis, tumorigenesis, and immune response. A limitation with the use of serial biopsy specimens was low quality of ribonucleic acid from tumors that respond to highly effective therapy. Another 'key limitation' is timing of the post-treatment biopsy, because 24 h may be too late to adequately assess the impact of hyperthermia on gene expression.

  3. Identification of differential expression of genes in hepatocellular carcinoma by suppression subtractive hybridization combined cDNA microarray.

    Science.gov (United States)

    Liu, Yuefang; Zhu, Xiaojing; Zhu, Jin; Liao, Shibing; Tang, Qi; Liu, Kaikun; Guan, Xiaohong; Zhang, Jianping; Feng, Zhenqing

    2007-10-01

    The genetic background of hepatocellular carcinoma (HCC) has yet to be completely understood. Here, we describe the application of suppression subtractive hybridization (SSH) coupled with cDNA microarray analysis for the isolation and identification of differential expression of genes in HCC. Twenty-six known genes were validated as up-regulated and 19 known genes as down-regulated in HCC. The known genes identified were found to have diverse functions. In addition to the overexpression of AFP, these genes (increased in the presence of HCC) are involved in many processes, such as transcription and protein biosynthesis (HNRPDL, PABPC1, POLR2K, SRP9, SNRPA, and six ribosomal protein genes including RPL8, RPL14, RPL41, RPS5, RPS17, RPS24), the metabolism of lipids and proteins (FADS1, ApoA-II, ApoM, FTL), cell proliferation (Syndecan-2, and Annexin A2), and signal transduction (LRRC28 and FMR1). Additionally, a glutathione-binding protein involved in the detoxification of methylglyoxal known as GLO1 and an enzyme which increases the formation of prostaglandin E(2) known as PLA2G10 were up-regulated in HCC. Among the underexpressed genes discovered in HCC, most were responsible for liver-synthesized proteins (fibrinogen, complement species, amyloid, albumin, haptoglobin, hemopexin and orosomucoid). The enzyme implicated in the biotransformation of CYP family members (LOC644587) was decreased. The genes coding enzymes ADH1C, ALDH6A1, ALDOB, Arginase and CES1 were also found. Additionally, we isolated a zinc transporter (Zip14) and a function-unknown gene named ZBTB11 (Zinc finger and BTB domain containing 11) which were underexpressed, and seven expression sequence tags deregulated in HCC without significant homology reported in the public database. Essentially, by using SSH combined with a cDNA microarray we have identified a number of genes associated with HCC, most of which have not been previously reported. Further characterization of these differentially expressed

  4. Understanding the radiosensitivity of hematopoietic stem cells through CDNA micro-arrays profiling

    Energy Technology Data Exchange (ETDEWEB)

    Pawlik, A.; Cebo, Ch.; Vaigot, P.; Tronik-Le Roux, D. [Evry Univ., Lab. de Genomique et Radiobiologie de l' Hematopoiese, Service de Genomique Fonctionnelle, CEA, 91 (France)

    2006-07-01

    Eradication of circulating hematopoietic cells has been long known to be the first noticeable somatic effect following total body ionizing radiation (IR) exposure. Among these hematopoietic cells a marked differences in sensitivity to IR have been documented reflecting the remarkable degree of heterogeneity in cell type, proliferative capacity and cell cycle status within the bone marrow cells. From all the hematopoietic cells, the small lymphocyte has the greatest radiosensitivity. In fact, a decline in absolute lymphocyte count has been used to assess IR dose in the early phase of observation after IR exposure. At moderate doses, bone marrow recovery is triggered by the differentiation of stem/early progenitor cells, which confirms further their differential sensitivity to radiation exposure. Although differences in radiosensitivity of the stem cell pool have also been documented, little is known from a molecular viewpoint. To gain insight into the molecular programs underlying the response o f hematopoietic cells to radiation exposure, we have applied a genome wide analysis strategy based on cDNA micro arrays. This technology offers a unique opportunity to dissect complex biological process by assessing three types of questions, which are, in order of complexity: Which genes are differentially expressed among the samples studied:Which genes are expressed in a coordinated manner and what are the regulators involved,what are the global biological pathways mobilized. To answer these questions transcriptional changes occurring after exposure of mice to whole body irradiation (2 Gy) were monitored in bone marrow and spleen. The time course was established in vivo and encompassed the reversible eradication of cells. For each kinetic point RNA was collected from both, spleen or sorted B.M. populations from irradiated and sham irradiated mice. The sham irradiated mice were used to eliminate stress modifications due to handling.The results highlight numerous

  5. Genomic Profiles in Stage I Primary Non Small Cell Lung Cancer Using Comparative Genomic Hybridization Analysis of cDNA Microarrays

    Directory of Open Access Journals (Sweden)

    Feng Jiang

    2004-09-01

    Full Text Available To investigate the genomic aberrations that are involved in lung tumorigenesis and therefore may be developed as biomarkers for lung cancer diagnosis, we characterized the genomic copy number changes associated with individual genes in 14 tumors from patients with primary non small cell lung cancer (NSCLC. Six squamous cell carcinomas (SQCAs and eight adenocarcinomas (ADCAs were examined by high-resolution comparative genomic hybridization (CGH analysis of cDNA microarray. The SQCAs and ADCAs shared common frequency distributions of recurrent genomic gains of 63 genes and losses of 72 genes. Cluster analysis using 57 genes defined the genomic differences between these two major histologic types of NSCLC. Genomic aberrations from a set of 18 genes showed distinct difference of primary ADCAs from their paired normal lung tissues. The genomic copy number of four genes was validated by fluorescence in situ hybridization of 32 primary NSCLC tumors, including those used for cDNA microarray CGH analysis; a strong correlation with cDNA microarray CGH data emerged. The identified genomic aberrations may be involved in the initiation and progression of lung tumorigenesis and, most importantly, may be developed as new biomarkers for the early detection and classification of lung cancer.

  6. Monitoring expression profiles of rice (Oryza sativa L.) genes under abiotic stresses using cDNA Microarray Analysis (abstract)

    International Nuclear Information System (INIS)

    Rabbani, M.A.

    2005-01-01

    Transcript regulation in response to cold, drought, high salinity and ABA application was investigated in rice (Oryza sativa L., Nipponbare) with microarray analysis including approx. 1700 independent DNA elements derived from three cDNA libraries constructed from 15-day old rice seedlings stressed with drought, cold and high salinity. A total of 141 non-redundant genes were identified, whose expression ratios were more than three-fold compared with the control genes for at least one of stress treatments in microarray analysis. However, after RNA gel blot analysis, a total of 73 genes were identified, among them the transcripts of 36, 62, 57 and 43 genes were found increased after cold, drought, high salinity and ABA application, respectively. Sixteen of these identified genes have been reported previously to be stress inducible in rice, while 57 of which are novel that have not been reported earlier as stress responsive in rice. We observed a strong association in the expression patterns of stress responsive genes and found 15 stress inducible genes that responded to all four treatments. Based on Venn diagram analysis, 56 genes were induced by both drought and high salinity, whereas 22 genes were upregulated by both cold and high salinity stress. Similarly 43 genes were induced by both drought stress and ABA application, while only 17 genes were identified as cold and ABA inducible genes. These results indicated the existence of greater cross talk between drought, ABA and high salinity stress signaling processes than those between cold and ABA, and cold and high salinity stress signaling pathways. The cold, drought, high salinity and ABA inducible genes were classified into four gene groups from their expression profiles. Analysis of data enabled us to identify a number of promoters and possible cis-acting DNA elements of several genes induced by a variety of abiotic stresses by combining expression data with genomic sequence data of rice. Comparative analysis of

  7. Statistical Analysis of Microarray Data with Replicated Spots: A Case Study with Synechococcus WH8102

    Directory of Open Access Journals (Sweden)

    E. V. Thomas

    2009-01-01

    Full Text Available Until recently microarray experiments often involved relatively few arrays with only a single representation of each gene on each array. A complete genome microarray with multiple spots per gene (spread out spatially across the array was developed in order to compare the gene expression of a marine cyanobacterium and a knockout mutant strain in a defined artificial seawater medium. Statistical methods were developed for analysis in the special situation of this case study where there is gene replication within an array and where relatively few arrays are used, which can be the case with current array technology. Due in part to the replication within an array, it was possible to detect very small changes in the levels of expression between the wild type and mutant strains. One interesting biological outcome of this experiment is the indication of the extent to which the phosphorus regulatory system of this cyanobacterium affects the expression of multiple genes beyond those strictly involved in phosphorus acquisition.

  8. Comparing gene discovery from Affymetrix GeneChip microarrays and Clontech PCR-select cDNA subtraction: a case study

    Science.gov (United States)

    Cao, Wuxiong; Epstein, Charles; Liu, Hong; DeLoughery, Craig; Ge, Nanxiang; Lin, Jieyi; Diao, Rong; Cao, Hui; Long, Fan; Zhang, Xin; Chen, Yangde; Wright, Paul S; Busch, Steve; Wenck, Michelle; Wong, Karen; Saltzman, Alan G; Tang, Zhihua; Liu, Li; Zilberstein, Asher

    2004-01-01

    Background Several high throughput technologies have been employed to identify differentially regulated genes that may be molecular targets for drug discovery. Here we compared the sets of differentially regulated genes discovered using two experimental approaches: a subtracted suppressive hybridization (SSH) cDNA library methodology and Affymetrix GeneChip® technology. In this "case study" we explored the transcriptional pattern changes during the in vitro differentiation of human monocytes to myeloid dendritic cells (DC), and evaluated the potential for novel gene discovery using the SSH methodology. Results The same RNA samples isolated from peripheral blood monocyte precursors and immature DC (iDC) were used for GeneChip microarray probing and SSH cDNA library construction. 10,000 clones from each of the two-way SSH libraries (iDC-monocytes and monocytes-iDC) were picked for sequencing. About 2000 transcripts were identified for each library from 8000 successful sequences. Only 70% to 75% of these transcripts were represented on the U95 series GeneChip microarrays, implying that 25% to 30% of these transcripts might not have been identified in a study based only on GeneChip microarrays. In addition, about 10% of these transcripts appeared to be "novel", although these have not yet been closely examined. Among the transcripts that are also represented on the chips, about a third were concordantly discovered as differentially regulated between iDC and monocytes by GeneChip microarray transcript profiling. The remaining two thirds were either not inferred as differentially regulated from GeneChip microarray data, or were called differentially regulated but in the opposite direction. This underscores the importance both of generating reciprocal pairs of SSH libraries, and of real-time RT-PCR confirmation of the results. Conclusions This study suggests that SSH could be used as an alternative and complementary transcript profiling tool to GeneChip microarrays

  9. Systematic spatial bias in DNA microarray hybridization is caused by probe spot position-dependent variability in lateral diffusion.

    Science.gov (United States)

    Steger, Doris; Berry, David; Haider, Susanne; Horn, Matthias; Wagner, Michael; Stocker, Roman; Loy, Alexander

    2011-01-01

    The hybridization of nucleic acid targets with surface-immobilized probes is a widely used assay for the parallel detection of multiple targets in medical and biological research. Despite its widespread application, DNA microarray technology still suffers from several biases and lack of reproducibility, stemming in part from an incomplete understanding of the processes governing surface hybridization. In particular, non-random spatial variations within individual microarray hybridizations are often observed, but the mechanisms underpinning this positional bias remain incompletely explained. This study identifies and rationalizes a systematic spatial bias in the intensity of surface hybridization, characterized by markedly increased signal intensity of spots located at the boundaries of the spotted areas of the microarray slide. Combining observations from a simplified single-probe block array format with predictions from a mathematical model, the mechanism responsible for this bias is found to be a position-dependent variation in lateral diffusion of target molecules. Numerical simulations reveal a strong influence of microarray well geometry on the spatial bias. Reciprocal adjustment of the size of the microarray hybridization chamber to the area of surface-bound probes is a simple and effective measure to minimize or eliminate the diffusion-based bias, resulting in increased uniformity and accuracy of quantitative DNA microarray hybridization.

  10. Systematic spatial bias in DNA microarray hybridization is caused by probe spot position-dependent variability in lateral diffusion.

    Directory of Open Access Journals (Sweden)

    Doris Steger

    Full Text Available The hybridization of nucleic acid targets with surface-immobilized probes is a widely used assay for the parallel detection of multiple targets in medical and biological research. Despite its widespread application, DNA microarray technology still suffers from several biases and lack of reproducibility, stemming in part from an incomplete understanding of the processes governing surface hybridization. In particular, non-random spatial variations within individual microarray hybridizations are often observed, but the mechanisms underpinning this positional bias remain incompletely explained.This study identifies and rationalizes a systematic spatial bias in the intensity of surface hybridization, characterized by markedly increased signal intensity of spots located at the boundaries of the spotted areas of the microarray slide. Combining observations from a simplified single-probe block array format with predictions from a mathematical model, the mechanism responsible for this bias is found to be a position-dependent variation in lateral diffusion of target molecules. Numerical simulations reveal a strong influence of microarray well geometry on the spatial bias.Reciprocal adjustment of the size of the microarray hybridization chamber to the area of surface-bound probes is a simple and effective measure to minimize or eliminate the diffusion-based bias, resulting in increased uniformity and accuracy of quantitative DNA microarray hybridization.

  11. Transcriptomic identification of candidate genes involved in sunflower responses to chilling and salt stresses based on cDNA microarray analysis.

    Science.gov (United States)

    Fernandez, Paula; Di Rienzo, Julio; Fernandez, Luis; Hopp, H Esteban; Paniego, Norma; Heinz, Ruth A

    2008-01-26

    Considering that sunflower production is expanding to arid regions, tolerance to abiotic stresses as drought, low temperatures and salinity arises as one of the main constrains nowadays. Differential organ-specific sunflower ESTs (expressed sequence tags) were previously generated by a subtractive hybridization method that included a considerable number of putative abiotic stress associated sequences. The objective of this work is to analyze concerted gene expression profiles of organ-specific ESTs by fluorescence microarray assay, in response to high sodium chloride concentration and chilling treatments with the aim to identify and follow up candidate genes for early responses to abiotic stress in sunflower. Abiotic-related expressed genes were the target of this characterization through a gene expression analysis using an organ-specific cDNA fluorescence microarray approach in response to high salinity and low temperatures. The experiment included three independent replicates from leaf samples. We analyzed 317 unigenes previously isolated from differential organ-specific cDNA libraries from leaf, stem and flower at R1 and R4 developmental stage. A statistical analysis based on mean comparison by ANOVA and ordination by Principal Component Analysis allowed the detection of 80 candidate genes for either salinity and/or chilling stresses. Out of them, 50 genes were up or down regulated under both stresses, supporting common regulatory mechanisms and general responses to chilling and salinity. Interestingly 15 and 12 sequences were up regulated or down regulated specifically in one stress but not in the other, respectively. These genes are potentially involved in different regulatory mechanisms including transcription/translation/protein degradation/protein folding/ROS production or ROS-scavenging. Differential gene expression patterns were confirmed by qRT-PCR for 12.5% of the microarray candidate sequences. Eighty genes isolated from organ-specific cDNA libraries

  12. Transcriptomic identification of candidate genes involved in sunflower responses to chilling and salt stresses based on cDNA microarray analysis

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    Paniego Norma

    2008-01-01

    Full Text Available Abstract Background Considering that sunflower production is expanding to arid regions, tolerance to abiotic stresses as drought, low temperatures and salinity arises as one of the main constrains nowadays. Differential organ-specific sunflower ESTs (expressed sequence tags were previously generated by a subtractive hybridization method that included a considerable number of putative abiotic stress associated sequences. The objective of this work is to analyze concerted gene expression profiles of organ-specific ESTs by fluorescence microarray assay, in response to high sodium chloride concentration and chilling treatments with the aim to identify and follow up candidate genes for early responses to abiotic stress in sunflower. Results Abiotic-related expressed genes were the target of this characterization through a gene expression analysis using an organ-specific cDNA fluorescence microarray approach in response to high salinity and low temperatures. The experiment included three independent replicates from leaf samples. We analyzed 317 unigenes previously isolated from differential organ-specific cDNA libraries from leaf, stem and flower at R1 and R4 developmental stage. A statistical analysis based on mean comparison by ANOVA and ordination by Principal Component Analysis allowed the detection of 80 candidate genes for either salinity and/or chilling stresses. Out of them, 50 genes were up or down regulated under both stresses, supporting common regulatory mechanisms and general responses to chilling and salinity. Interestingly 15 and 12 sequences were up regulated or down regulated specifically in one stress but not in the other, respectively. These genes are potentially involved in different regulatory mechanisms including transcription/translation/protein degradation/protein folding/ROS production or ROS-scavenging. Differential gene expression patterns were confirmed by qRT-PCR for 12.5% of the microarray candidate sequences. Conclusion

  13. Extending Immunological Profiling in the Gilthead Sea Bream, Sparus aurata, by Enriched cDNA Library Analysis, Microarray Design and Initial Studies upon the Inflammatory Response to PAMPs

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    Sebastian Boltaña

    2017-02-01

    Full Text Available This study describes the development and validation of an enriched oligonucleotide-microarray platform for Sparus aurata (SAQ to provide a platform for transcriptomic studies in this species. A transcriptome database was constructed by assembly of gilthead sea bream sequences derived from public repositories of mRNA together with reads from a large collection of expressed sequence tags (EST from two extensive targeted cDNA libraries characterizing mRNA transcripts regulated by both bacterial and viral challenge. The developed microarray was further validated by analysing monocyte/macrophage activation profiles after challenge with two Gram-negative bacterial pathogen-associated molecular patterns (PAMPs; lipopolysaccharide (LPS and peptidoglycan (PGN. Of the approximately 10,000 EST sequenced, we obtained a total of 6837 EST longer than 100 nt, with 3778 and 3059 EST obtained from the bacterial-primed and from the viral-primed cDNA libraries, respectively. Functional classification of contigs from the bacterial- and viral-primed cDNA libraries by Gene Ontology (GO showed that the top five represented categories were equally represented in the two libraries: metabolism (approximately 24% of the total number of contigs, carrier proteins/membrane transport (approximately 15%, effectors/modulators and cell communication (approximately 11%, nucleoside, nucleotide and nucleic acid metabolism (approximately 7.5% and intracellular transducers/signal transduction (approximately 5%. Transcriptome analyses using this enriched oligonucleotide platform identified differential shifts in the response to PGN and LPS in macrophage-like cells, highlighting responsive gene-cassettes tightly related to PAMP host recognition. As observed in other fish species, PGN is a powerful activator of the inflammatory response in S. aurata macrophage-like cells. We have developed and validated an oligonucleotide microarray (SAQ that provides a platform enriched for the study

  14. Biomphalaria glabrata transcriptome: cDNA microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to Schistosoma mansoni

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    Rollinson David

    2008-12-01

    Full Text Available Abstract Background Biomphalaria glabrata is an intermediate snail host for Schistosoma mansoni, one of the important schistosomes infecting man. B. glabrata/S. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. Examining differential gene expression between S. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. Results We have developed a 2053 element cDNA microarray for B. glabrata containing clones from ORESTES (Open Reading frame ESTs libraries, suppression subtractive hybridization (SSH libraries and clones identified in previous expression studies. Snail haemocyte RNA, extracted from parasite-challenged resistant and susceptible snails, 2 to 24 h post-exposure to S. mansoni, was hybridized to the custom made cDNA microarray and 98 differentially expressed genes or gene clusters were identified, 94 resistant-associated and 4 susceptible-associated. Quantitative PCR analysis verified the cDNA microarray results for representative transcripts. Differentially expressed genes were annotated and clustered using gene ontology (GO terminology and Kyoto Encyclopaedia of Genes and Genomes (KEGG pathway analysis. 61% of the identified differentially expressed genes have no known function including the 4 susceptible strain-specific transcripts. Resistant strain-specific expression of genes implicated in innate immunity of invertebrates was identified, including hydrolytic enzymes such as cathepsin L, a cysteine proteinase involved in lysis of phagocytosed particles; metabolic enzymes such as ornithine decarboxylase, the rate-limiting enzyme in the production of polyamines, important in inflammation and infection processes, as well as scavenging damaging free radicals produced during production of reactive oxygen species; stress response genes such as HSP70; proteins involved in signalling, such as importin 7

  15. Biomphalaria glabrata transcriptome: cDNA microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to Schistosoma mansoni

    Science.gov (United States)

    Lockyer, Anne E; Spinks, Jenny; Kane, Richard A; Hoffmann, Karl F; Fitzpatrick, Jennifer M; Rollinson, David; Noble, Leslie R; Jones, Catherine S

    2008-01-01

    Background Biomphalaria glabrata is an intermediate snail host for Schistosoma mansoni, one of the important schistosomes infecting man. B. glabrata/S. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. Examining differential gene expression between S. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. Results We have developed a 2053 element cDNA microarray for B. glabrata containing clones from ORESTES (Open Reading frame ESTs) libraries, suppression subtractive hybridization (SSH) libraries and clones identified in previous expression studies. Snail haemocyte RNA, extracted from parasite-challenged resistant and susceptible snails, 2 to 24 h post-exposure to S. mansoni, was hybridized to the custom made cDNA microarray and 98 differentially expressed genes or gene clusters were identified, 94 resistant-associated and 4 susceptible-associated. Quantitative PCR analysis verified the cDNA microarray results for representative transcripts. Differentially expressed genes were annotated and clustered using gene ontology (GO) terminology and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. 61% of the identified differentially expressed genes have no known function including the 4 susceptible strain-specific transcripts. Resistant strain-specific expression of genes implicated in innate immunity of invertebrates was identified, including hydrolytic enzymes such as cathepsin L, a cysteine proteinase involved in lysis of phagocytosed particles; metabolic enzymes such as ornithine decarboxylase, the rate-limiting enzyme in the production of polyamines, important in inflammation and infection processes, as well as scavenging damaging free radicals produced during production of reactive oxygen species; stress response genes such as HSP70; proteins involved in signalling, such as importin 7 and copine 1

  16. Comparing gene discovery from Affymetrix GeneChip microarrays and Clontech PCR-select cDNA subtraction: a case study

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    Wright Paul S

    2004-04-01

    Full Text Available Abstract Background Several high throughput technologies have been employed to identify differentially regulated genes that may be molecular targets for drug discovery. Here we compared the sets of differentially regulated genes discovered using two experimental approaches: a subtracted suppressive hybridization (SSH cDNA library methodology and Affymetrix GeneChip® technology. In this "case study" we explored the transcriptional pattern changes during the in vitro differentiation of human monocytes to myeloid dendritic cells (DC, and evaluated the potential for novel gene discovery using the SSH methodology. Results The same RNA samples isolated from peripheral blood monocyte precursors and immature DC (iDC were used for GeneChip microarray probing and SSH cDNA library construction. 10,000 clones from each of the two-way SSH libraries (iDC-monocytes and monocytes-iDC were picked for sequencing. About 2000 transcripts were identified for each library from 8000 successful sequences. Only 70% to 75% of these transcripts were represented on the U95 series GeneChip microarrays, implying that 25% to 30% of these transcripts might not have been identified in a study based only on GeneChip microarrays. In addition, about 10% of these transcripts appeared to be "novel", although these have not yet been closely examined. Among the transcripts that are also represented on the chips, about a third were concordantly discovered as differentially regulated between iDC and monocytes by GeneChip microarray transcript profiling. The remaining two thirds were either not inferred as differentially regulated from GeneChip microarray data, or were called differentially regulated but in the opposite direction. This underscores the importance both of generating reciprocal pairs of SSH libraries, and of real-time RT-PCR confirmation of the results. Conclusions This study suggests that SSH could be used as an alternative and complementary transcript profiling tool to

  17. Identification of testis-relevant genes using in silico analysis from testis ESTs and cDNA microarray in the black tiger shrimp (Penaeus monodon

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    Wongsurawat Thidathip

    2010-08-01

    Full Text Available Abstract Background Poor reproductive maturation of the black tiger shrimp (Penaeus monodon in captivity is one of the serious threats to sustainability of the shrimp farming industry. Understanding molecular mechanisms governing reproductive maturation processes requires the fundamental knowledge of integrated expression profiles in gonads of this economically important species. In P. monodon, a non-model species for which the genome sequence is not available, expressed sequence tag (EST and cDNA microarray analyses can help reveal important transcripts relevant to reproduction and facilitate functional characterization of transcripts with important roles in male reproductive development and maturation. Results In this study, a conventional testis EST library was exploited to reveal novel transcripts. A total of 4,803 ESTs were unidirectionally sequenced and analyzed in silico using a customizable data analysis package, ESTplus. After sequence assembly, 2,702 unique sequences comprised of 424 contigs and 2,278 singletons were identified; of these, 1,133 sequences are homologous to genes with known functions. The sequences were further characterized according to gene ontology categories (41% biological process, 24% molecular function, 35% cellular component. Through comparison with EST libraries of other tissues of P. monodon, 1,579 transcripts found only in the testis cDNA library were identified. A total of 621 ESTs have not been identified in penaeid shrimp. Furthermore, cDNA microarray analysis revealed several ESTs homologous to testis-relevant genes were more preferentially expressed in testis than in ovary. Representatives of these transcripts, homologs of saposin (PmSap and Dmc1 (PmDmc1, were further characterized by RACE-PCR. The more abundant expression levels in testis than ovary of PmSap and PmDmc1 were verified by quantitative real-time PCR in juveniles and wild broodstock of P. monodon. Conclusions Without a genome sequence, a

  18. Identification of differentially-expressed genes potentially implicated in drought response in pitaya (Hylocereus undatus) by suppression subtractive hybridization and cDNA microarray analysis.

    Science.gov (United States)

    Fan, Qing-Jie; Yan, Feng-Xia; Qiao, Guang; Zhang, Bing-Xue; Wen, Xiao-Peng

    2014-01-01

    Drought is one of the most severe threats to the growth, development and yield of plant. In order to unravel the molecular basis underlying the high tolerance of pitaya (Hylocereus undatus) to drought stress, suppression subtractive hybridization (SSH) and cDNA microarray approaches were firstly combined to identify the potential important or novel genes involved in the plant responses to drought stress. The forward (drought over drought-free) and reverse (drought-free over drought) suppression subtractive cDNA libraries were constructed using in vitro shoots of cultivar 'Zihonglong' exposed to drought stress and drought-free (control). A total of 2112 clones, among which half were from either forward or reverse SSH library, were randomly picked up to construct a pitaya cDNA microarray. Microarray analysis was carried out to verify the expression fluctuations of this set of clones upon drought treatment compared with the controls. A total of 309 expressed sequence tags (ESTs), 153 from forward library and 156 from reverse library, were obtained, and 138 unique ESTs were identified after sequencing by clustering and blast analyses, which included genes that had been previously reported as responsive to water stress as well as some functionally unknown genes. Thirty six genes were mapped to 47 KEGG pathways, including carbohydrate metabolism, lipid metabolism, energy metabolism, nucleotide metabolism, and amino acid metabolism of pitaya. Expression analysis of the selected ESTs by reverse transcriptase polymerase chain reaction (RT-PCR) corroborated the results of differential screening. Moreover, time-course expression patterns of these selected ESTs further confirmed that they were closely responsive to drought treatment. Among the differentially expressed genes (DEGs), many are related to stress tolerances including drought tolerance. Thereby, the mechanism of drought tolerance of this pitaya genotype is a very complex physiological and biochemical process, in

  19. Genome-Wide Screening of Genes Showing Altered Expression in Liver Metastases of Human Colorectal Cancers by cDNA Microarray

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    Rempei Yanagawa

    2001-01-01

    Full Text Available In spite of intensive and increasingly successful attempts to determine the multiple steps involved in colorectal carcinogenesis, the mechanisms responsible for metastasis of colorectal tumors to the liver remain to be clarified. To identify genes that are candidates for involvement in the metastatic process, we analyzed genome-wide expression profiles of 10 primary colorectal cancers and their corresponding metastatic lesions by means of a cDNA microarray consisting of 9121 human genes. This analysis identified 40 genes whose expression was commonly upregulated in metastatic lesions, and 7 that were commonly downregulated. The upregulated genes encoded proteins involved in cell adhesion, or remodeling of the actin cytoskeleton. Investigation of the functions of more of the altered genes should improve our understanding of metastasis and may identify diagnostic markers and/or novel molecular targets for prevention or therapy of metastatic lesions.

  20. cDNA microarray assessment of early gene expression profiles in Escherichia coli cells exposed to a mixture of heavy metals.

    Science.gov (United States)

    Gómez-Sagasti, María T; Becerril, José M; Martín, Iker; Epelde, Lur; Garbisu, Carlos

    2014-08-01

    Many contaminated sites are characterized by the presence of different metals, thus increasing the complexity of toxic responses in exposed organisms. Within toxicogenomics, transcriptomics can be approached through the use of microarrays aimed at producing a genetic fingerprint for the response of model organisms to the presence of chemicals. We studied temporal changes in the early gene expression profiles of Escherichia coli cells exposed to three metal doses of a polymetallic solution over three exposure times, through the application of cDNA microarray technology. In the absence of metals, many genes belonging to a variety of cellular functions were up- and down-regulated over time. At the lowest metal dose, an activation of metal-specific transporters (Cus and ZraP proteins) and a mobilization of glutathione transporters involved in metal sequestration and trafficking was observed over time; this metal dose resulted in the generation of ROS capable of stimulating the transcription of Mn-superoxide dismutase, the assembly of Fe-S clusters and the synthesis of cysteine. At the intermediate dose, an overexpression of ROS scavengers (AhpF, KatG, and YaaA) and heat shock proteins (ClpP, HslV, DnaK, and IbpAB) was observed. Finally, at the highest dose, E. coli cells showed a repression of genes related with DNA mutation correctors (MutY glycopeptidases).

  1. Hematopoietic Lineage Transcriptome Stability and Representation in PAXgeneTM Collected Peripheral Blood Utilising SPIA Single-Stranded cDNA Probes for Microarray

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    Laura Kennedy

    2008-01-01

    Full Text Available Peripheral blood as a surrogate tissue for transcriptome profiling holds great promise for the discovery of diagnostic and prognostic disease biomarkers, particularly when target tissues of disease are not readily available. To maximize the reliability of gene expression data generated from clinical blood samples, both the sample collection and the microarray probe generation methods should be optimized to provide stabilized, reproducible and representative gene expression profiles faithfully representing the transcriptional profiles of the constituent blood cell types present in the circulation. Given the increasing innovation in this field in recent years, we investigated a combination of methodological advances in both RNA stabilisation and microarray probe generation with the goal of achieving robust, reliable and representative transcriptional profiles from whole blood. To assess the whole blood profiles, the transcriptomes of purified blood cell types were measured and compared with the global transcriptomes measured in whole blood. The results demonstrate that a combination of PAXgeneTM RNA stabilising technology and single-stranded cDNA probe generation afforded by the NuGEN Ovation RNA amplification system V2TM enables an approach that yields faithful representation of specific hematopoietic cell lineage transcriptomes in whole blood without the necessity for prior sample fractionation, cell enrichment or globin reduction. Storage stability assessments of the PAXgeneTM blood samples also advocate a short, fixed room temperature storage time for all PAXgeneTM blood samples collected for the purposes of global transcriptional profiling in clinical studies.

  2. Hematopoietic Lineage Transcriptome Stability and Representation in PAXgene Collected Peripheral Blood Utilising SPIA Single-Stranded cDNA Probes for Microarray.

    Science.gov (United States)

    Kennedy, Laura; Vass, J Keith; Haggart, D Ross; Moore, Steve; Burczynski, Michael E; Crowther, Dan; Miele, Gino

    2008-08-25

    Peripheral blood as a surrogate tissue for transcriptome profiling holds great promise for the discovery of diagnostic and prognostic disease biomarkers, particularly when target tissues of disease are not readily available. To maximize the reliability of gene expression data generated from clinical blood samples, both the sample collection and the microarray probe generation methods should be optimized to provide stabilized, reproducible and representative gene expression profiles faithfully representing the transcriptional profiles of the constituent blood cell types present in the circulation. Given the increasing innovation in this field in recent years, we investigated a combination of methodological advances in both RNA stabilisation and microarray probe generation with the goal of achieving robust, reliable and representative transcriptional profiles from whole blood. To assess the whole blood profiles, the transcriptomes of purified blood cell types were measured and compared with the global transcriptomes measured in whole blood. The results demonstrate that a combination of PAXgene() RNA stabilising technology and single-stranded cDNA probe generation afforded by the NuGEN Ovation RNA amplification system V2() enables an approach that yields faithful representation of specific hematopoietic cell lineage transcriptomes in whole blood without the necessity for prior sample fractionation, cell enrichment or globin reduction. Storage stability assessments of the PAXgene() blood samples also advocate a short, fixed room temperature storage time for all PAXgene() blood samples collected for the purposes of global transcriptional profiling in clinical studies.

  3. Hematopoietic Lineage Transcriptome Stability and Representation in PAXgene™ Collected Peripheral Blood Utilising SPIA Single-Stranded cDNA Probes for Microarray

    Science.gov (United States)

    Kennedy, Laura; Vass, J. Keith; Haggart, D. Ross; Moore, Steve; Burczynski, Michael E.; Crowther, Dan; Miele, Gino

    2008-01-01

    Peripheral blood as a surrogate tissue for transcriptome profiling holds great promise for the discovery of diagnostic and prognostic disease biomarkers, particularly when target tissues of disease are not readily available. To maximize the reliability of gene expression data generated from clinical blood samples, both the sample collection and the microarray probe generation methods should be optimized to provide stabilized, reproducible and representative gene expression profiles faithfully representing the transcriptional profiles of the constituent blood cell types present in the circulation. Given the increasing innovation in this field in recent years, we investigated a combination of methodological advances in both RNA stabilisation and microarray probe generation with the goal of achieving robust, reliable and representative transcriptional profiles from whole blood. To assess the whole blood profiles, the transcriptomes of purified blood cell types were measured and compared with the global transcriptomes measured in whole blood. The results demonstrate that a combination of PAXgene™ RNA stabilising technology and single-stranded cDNA probe generation afforded by the NuGEN Ovation RNA amplification system V2™ enables an approach that yields faithful representation of specific hematopoietic cell lineage transcriptomes in whole blood without the necessity for prior sample fractionation, cell enrichment or globin reduction. Storage stability assessments of the PAXgene™ blood samples also advocate a short, fixed room temperature storage time for all PAXgene™ blood samples collected for the purposes of global transcriptional profiling in clinical studies. PMID:19578521

  4. Comparative transcript profiling of gene expression between seedless Ponkan mandarin and its seedy wild type during floral organ development by suppression subtractive hybridization and cDNA microarray

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    Qiu Wen-Ming

    2012-08-01

    Full Text Available Abstract Background Seedlessness is an important agronomic trait for citrus, and male sterility (MS is one main cause of seedless citrus fruit. However, the molecular mechanism of citrus seedlessness remained not well explored. Results An integrative strategy combining suppression subtractive hybridization (SSH library with cDNA microarray was employed to study the underlying mechanism of seedlessness of a Ponkan mandarin seedless mutant (Citrus reticulata Blanco. Screening with custom microarray, a total of 279 differentially expressed clones were identified, and 133 unigenes (43 contigs and 90 singletons were obtained after sequencing. Gene Ontology (GO distribution based on biological process suggested that the majority of differential genes are involved in metabolic process and respond to stimulus and regulation of biology process; based on molecular function they function as DNA/RNA binding or have catalytic activity and oxidoreductase activity. A gene encoding male sterility-like protein was highly up-regulated in the seedless mutant compared with the wild type, while several transcription factors (TFs such as AP2/EREBP, MYB, WRKY, NAC and C2C2-GATA zinc-finger domain TFs were down-regulated. Conclusion Our research highlighted some candidate pathways that participated in the citrus male gametophyte development and could be beneficial for seedless citrus breeding in the future.

  5. Identification of late O{sub 3}-responsive genes in Arabidopsis thaliana by cDNA microarray analysis

    Energy Technology Data Exchange (ETDEWEB)

    D' Haese, D. [Univ. of Antwerp, Dept. of Biology, Antwerp (BE) and Univ. of Newcastle, School of Biology and Psychology, Div. of Biology, Newcastle-Upon-Tyne (United Kingdom); Horemans, N.; Coen, W. De; Guisez, Y. [Univ. of Antwerp, Dept. of Biology, Antwerp (Belgium)

    2006-09-15

    To better understand the response of a plant to 0{sub 3} stress, an integrated microarray analysis was performed on Arabidopsis plants exposed during 2 days to purified air or 150 nl l{sup -1} O{sub 3}, 8 h day-l. Agilent Arabidopsis 2 Oligo Microarrays were used of which the reliability was confirmed by quantitative real-time PCR of nine randomly selected genes. We confirmed the O{sub 3} responsiveness of heat shock proteins (HSPs), glutathione-S-tranferases and genes involved in cell wall stiffening and microbial defence. Whereas, a previous study revealed that during an early stage of the O{sub 3} stress response, gene expression was strongly dependent on jasmonic acid and ethylene, we report that at a later stage (48 h) synthesis of jasrnonic acid and ethylene was downregulated. In addition, we observed the simultaneous induction of salicylic acid synthesis and genes involved in programmed cell death and senescence. Also typically, the later stage of the response to O{sub 3} appeared to be the induction of the complete pathway leading to the biosynthesis of anthocyanin diglucosides and the induction of thioredoxin-based redox control. Surprisingly absent in the list of induced genes were genes involved in ASC-dependent antioxidation, few of which were found to be induced after 12 h of 0{sub 3} exposure in another study. We discuss these and other particular results of the microarray analysis and provide a map depicting significantly affected genes and their pathways highlighting their interrelationships and subcellular localization. (au)

  6. Profiling Ethylene-Responsive Genes Expressed in the Latex of the Mature Virgin Rubber Trees Using cDNA Microarray.

    Science.gov (United States)

    Nie, Zhiyi; Kang, Guijuan; Duan, Cuifang; Li, Yu; Dai, Longjun; Zeng, Rizhong

    2016-01-01

    Ethylene is commonly used as a latex stimulant of Hevea brasiliensis by application of ethephon (chloro-2-ethylphosphonic acid); however, the molecular mechanism by which ethylene increases latex production is not clear. To better understand the effects of ethylene stimulation on the laticiferous cells of rubber trees, a latex expressed sequence tag (EST)-based complementary DNA microarray containing 2,973 unique genes (probes) was first developed and used to analyze the gene expression changes in the latex of the mature virgin rubber trees after ethephon treatment at three different time-points: 8, 24 and 48 h. Transcript levels of 163 genes were significantly altered with fold-change values ≥ 2 or ≤ -2 (q-value latex actin cytoskeleton might play important roles in ethylene-induced increase of latex production. The results may provide useful insights into understanding the molecular mechanism underlying the effect of ethylene on latex metabolism of H. brasiliensis.

  7. Genetic profile of Egyptian hepatocellular-carcinoma associated with hepatitis C virus Genotype 4 by 15 K cDNA microarray: Preliminary study

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    Mansour Tarek

    2008-10-01

    Full Text Available Abstract Background Hepatocellular carcinoma (HCC is a preventable disease rather than a curable one, since there is no well-documented effective treatment modality until now, making the molecular study of this disease mandatory. Findings We studied gene expression profile of 17 Egyptian HCC patients associated with HCV genotype-4 infection by c-DNA microarray. Out of the 15,660 studied genes, 446 were differentially expressed; 180 of them were up regulated and 134 were down regulated. Seventeen genes out of the 180 up-regulated genes are involved in 28 different pathways. Protein phosphatase 3 (PPP3R1 is involved in 10 different pathways followed by fibroblast growth factor receptor 1 (FGFR1, Cas-Br-M ecotropic retroviral transforming sequence b (CBLB, spleen tyrosine kinase (SYK involved in three pathways; bone morphogenetic protein 8a (BMP8A, laminin alpha 3 (LAMA3, cell division cycle 23 (CDC23 involved in 2 pathways and NOTCH4 which regulate Notch signaling pathway. On the other hand, 25 out of the 134 down-regulated genes are involved in 20 different pathways. Integrin alpha V alpha polypeptide antigen CD51 (ITGVA is involved in 4 pathways followed by lymphotoxin alpha (TNF superfamily, member 1 (LTA involved in 3 pathways and alpha-2-macroglobulin (A2M, phosphorylase kinase alpha 2-liver (PHKA2 and MAGI1 membrane associated guanylate kinase 1 (MAGI1 involved in 2 pathways. In addition, 22 genes showed significantly differential expression between HCC cases with cirrhosis and without cirrhosis. Confirmation analysis was performed on subsets of these genes by RT-PCR, including some up-regulated genes such as CDK4, Bax, NOTCH4 and some down-regulated genes such as ISGF3G, TNF, and VISA. Conclusion This is the first preliminary study on gene expression profile in Egyptian HCC patients associated with HCV-Genotype-4 using the cDNA microarray. The identified genes could provide a new gate for prognostic and diagnostic markers for HCC associated

  8. Analysis of the effects of sex hormone background on the rat choroid plexus transcriptome by cDNA microarrays.

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    Telma Quintela

    Full Text Available The choroid plexus (CP are highly vascularized branched structures that protrude into the ventricles of the brain, and form a unique interface between the blood and the cerebrospinal fluid (CSF, the blood-CSF barrier, that are the main site of production and secretion of CSF. Sex hormones are widely recognized as neuroprotective agents against several neurodegenerative diseases, and the presence of sex hormones cognate receptors suggest that it may be a target for these hormones. In an effort to provide further insight into the neuroprotective mechanisms triggered by sex hormones we analyzed gene expression differences in the CP of female and male rats subjected to gonadectomy, using microarray technology. In gonadectomized female and male animals, 3045 genes were differentially expressed by 1.5-fold change, compared to sham controls. Analysis of the CP transcriptome showed that the top-five pathways significantly regulated by the sex hormone background are olfactory transduction, taste transduction, metabolism, steroid hormone biosynthesis and circadian rhythm pathways. These results represent the first overview of global expression changes in CP of female and male rats induced by gonadectomy and suggest that sex hormones are implicated in pathways with central roles in CP functions and CSF homeostasis.

  9. Microarray screening of suppression subtractive hybridization-PCR cDNA libraries identifies novel RNAs regulated by dehydration in the rat supraoptic nucleus.

    Science.gov (United States)

    Ghorbel, Mohamed T; Sharman, Greig; Hindmarch, Charles; Becker, Kevin G; Barrett, Tanya; Murphy, David

    2006-01-12

    The magnocellular neurons (MCNs) of the supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus are the principal site of biosynthesis of prepropeptide precursor of the antidiuretic hormone vasopressin (VP). This precursor is processed during anterograde axonal transportation to terminals in the posterior pituitary gland, where biologically active VP is stored until release into the general circulation in response to physiological activation of the SON by osmotic cues. By binding to V2-type receptors located in the kidney, VP decreases the amount of water lost in urine. Osmotic activation of the SON is accompanied by a dramatic morphological and functional remodeling. We have sought to understand the mechanistic basis of this plasticity in terms of the differential expression of genes. To identify such genes, we adopted an unbiased global approach based on suppressive subtractive hybridization-polymerase chain reaction (SSH-PCR) Using this method, we generated libraries of clones putatively differentially expressed in control vs. dehydrated SON. To rapidly screen these libraries, 1,152 clones were subjected to microarray analysis, resulting in the identification of 459 differentially expressed transcripts. cDNA clones corresponding to 56 of these RNAs were sequenced, revealing many of them to be novel expressed sequence tags (ESTs). Four transcripts were shown by in situ hybridization (ISH) to be significantly up- or downregulated in the SON after dehydration. These genes may represent novel effectors or mediators of SON physiological remodeling.

  10. Differential gene expression in a DNA double-strand-break repair mutant XRS-5 defective in Ku80. Analysis by cDNA microarray

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    Chan, John Y.H.; Chen, Lung-Kun; Chang, Jui-Feng [National Yang Ming Univ., Taipei, Taiwan (China). Inst. of Radiological Sciences] (and others)

    2001-12-01

    The ability of cells to rejoin DNA double-strand breaks (DSBs) usually correlates with their radiosensitivity. This correlation has been demonstrated in radiosensitive cells, including the Chinese hamster ovary mutant XRS-5. XRS-5 is defective in a DNA end-binding protein, Ku80, which is a component of a DNA-dependent protein kinase complex used for joining strand breaks. However, Ku80-deficient cells are known to be retarded in cell proliferation and growth as well as other yet to be identified defects. Using custom-made 600-gene cDNA microarray filters, we found differential gene expressions between the wild-type and XRS-5 cells. Defective Ku80 apparently affects the expression of several repair genes, including topoisomerase-I and -IIA, ERCC5, MLH1, and ATM. In contrast, other DNA repair-associated genes, such as GADD45A, EGR1 MDM2 and p53, were not affected. In addition, for large numbers of growth-associated genes, such as cyclins and clks, the growth factors and cytokines were also affected. Down-regulated expression was also found in several categories of seemingly unrelated genes, including apoptosis, angiogenesis, kinase and signaling, phosphatase, stress protein, proto-oncogenes and tumor suppressors, transcription and translation factors. A RT-PCR analysis confirmed that the XRS-5 cells used were defective in Ku80 expression. The diversified groups of genes being affected could mean that Ku80, a multi-functional DNA-binding protein, not only affects DNA repair, but is also involved in transcription regulation. Our data, taken together, indicate that there are specific genes being modulated in Ku80- deficient cells, and that some of the DNA repair pathways and other biological functions are apparently linked, suggesting that a defect in one gene could have global effects on many other processes. (author)

  11. Gene expression analysis of the rat testis after treatment with di(2-ethylhexyl) phthalate using cDNA microarray and real-time RT-PCR

    International Nuclear Information System (INIS)

    Kijima, Kazuyasu; Toyosawa, Kaoru; Yasuba, Masashi; Matsuoka, Nobuo; Adachi, Tetsuya; Komiyama, Masatoshi; Mori, Chisato

    2004-01-01

    To investigate the effects of di(2-ethylhexyl) phthalate (DEHP) on gene expression in rat testis, 6-week-old male Sprague-Dawley rats were given a single oral dose of 20 or 2000 mg/kg and euthanized 3, 6, 24, or 72 h thereafter. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells were significantly increased in the testis at 24 and 72 h after the exposure to 2000 mg/kg of DEHP. On cDNA microarray analysis, in addition to apoptosis-related genes, genes associated with atrophy, APEX nuclease, MutS homologue (E. coli), testosterone-repressed-prostatic-message-2 (TRPM-2), connective tissue growth factor, collagen alpha 2 type V, and cell adhesion kinase were differentially expressed. To investigate the relationship between histopathological alteration and gene expression, we selected genes associated with apoptosis and analyzed their expression by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). With 20 mg/kg of DEHP treatment, bcl-2, key gene related to apoptosis, was increased. Up-regulation of bcl-2, inhibitor of Apaf-1/caspase-9/caspase-2 cascade of apoptosis, may be related to the fact that no morphological apoptotic change was induced after dosing of 20 mg/kg DEHP. With 2000 mg/kg of DEHP treatment, the apoptotic activator cascade, Fas/FasL, FADD/caspase-8/caspase-3 cascade, and Apaf-1/caspase-9/caspase-2 cascade were increased and bcl-2 was decreased. Thus, these gene regulations might lead the cells into apoptosis in the case of high exposure to DEHP. In contrast, FADD/caspase-10/caspase-6 cascade and caspase-11/caspase-3 cascade were not increased. These results indicate that the cascades of FADD/caspase-10/caspase-6 and caspase-11/caspase-3 are not related to apoptosis with DEHP treatment

  12. Microarray and RT-PCR screening for white spot syndrome virus immediate-early genes in cycloheximide-treated shrimp

    International Nuclear Information System (INIS)

    Liu Wangjing; Chang Yunshiang; Wang Chunghsiung; Kou, Guang-Hsiung; Lo Chufang

    2005-01-01

    Here, we report for the first time the successful use of cycloheximide (CHX) as an inhibitor to block de novo viral protein synthesis during WSSV (white spot syndrome virus) infection. Sixty candidate IE (immediate-early) genes were identified using a global analysis microarray technique. RT-PCR showed that the genes corresponding to ORF126, ORF242 and ORF418 in the Taiwan isolate were consistently CHX-insensitive, and these genes were designated ie1, ie2 and ie3, respectively. The sequences for these IE genes also appear in the two other WSSV isolates that have been sequenced. Three corresponding ORFs were identified in the China WSSV isolate, but only an ORF corresponding to ie1 was predicted in the Thailand isolate. In a promoter activity assay in Sf9 insect cells using EGFP (enhanced green fluorescence protein) as a reporter, ie1 showed very strong promoter activity, producing higher EGFP signals than the insect Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) ie2 promoter

  13. Analysis of cellular responses to aflatoxin B{sub 1} in yeast expressing human cytochrome P450 1A2 using cDNA microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yingying [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Breeden, Linda L. [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Fan, Wenhong [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Zhao Lueping [Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Eaton, David L. [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fred Hutchinson Cancer Research Center, Seattle, WA (United States); Zarbl, Helmut [Departmental of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States) and Fred Hutchinson Cancer Research Center, Seattle, WA (United States)]. E-mail: hzarbl@fhcrc.org

    2006-01-29

    Aflatoxin B1 (AFB{sub 1}) is a potent human hepatotoxin and hepatocarcinogen produced by the mold Aspergillus flavus. In human, AFB{sub 1} is bioactivated by cytochrome P450 (CYP450) enzymes, primarily CYP1A2, to the genotoxic epoxide that forms N{sup 7}-guanine DNA adducts. To characterize the transcriptional responses to genotoxic insults from AFB{sub 1}, a strain of Saccharomyces cerevisiae engineered to express human CYP1A2 was exposed to doses of AFB{sub 1} that resulted in minimal lethality, but substantial genotoxicity. Flow cytometric analysis demonstrated a dose and time dependent S phase delay under the same treatment conditions, indicating a checkpoint response to DNA damage. Replicate cDNA microarray analyses of AFB{sub 1} treated cells showed that about 200 genes were significantly affected by the exposure. The genes activated by AFB{sub 1}-treatment included RAD51, DUN1 and other members of the DNA damage response signature reported in a previous study with methylmethane sulfonate and ionizing radiation [A.P. Gasch, M. Huang, S. Metzner, D. Botstein, S.J. Elledge, P.O. Brown, Genomic expression responses to DNA-damaging agents and the regulatory role of the yeast ATR homolog Mec1p, Mol. Biol. Cell 12 (2001) 2987-3003]. However, unlike previous studies using highly cytotoxic doses, environmental stress response genes [A.P. Gasch, P.T. Spellman, C.M. Kao, O. Carmel-Harel, M.B. Eisen, G. Storz, D. Botstein, P.O. Brown, Genomic expression programs in the response of yeast cells to environmental changes, Mol. Biol. Cell 11 (2000) 4241-4257] were largely unaffected by our dosing regimen. About half of the transcripts affected are also known to be cell cycle regulated. The most strongly repressed transcripts were those encoding the histone genes and a group of genes that are cell cycle regulated and peak in M phase and early G1. These include most of the known daughter-specific genes. The rapid and coordinated repression of histones and M/G1-specific

  14. Development of a microarray for simultaneous detection and differentiation of different tospoviruses that are serologically related to Tomato spotted wilt virus.

    Science.gov (United States)

    Liu, Lu-Yuan; Ye, He-Yi; Chen, Tsang-Hai; Chen, Tsung-Chi

    2017-01-10

    Tospoviruses, the plant-infecting genus in the family Bunyaviridae, are thrips borne and cause severe agricultural losses worldwide. Based on the serological relationships of the structural nucleocapsid protein (NP), the current tospoviruses are divided into six serogroups. The use of NP-antisera is convenient for virus detection, but it is insufficient to identify virus species grouped in a serogroup due to the serological cross-reaction. Alternatively, virus species can be identified by the N gene amplification using specific primers. Tomato spotted wilt virus (TSWV) is the type species of the genus Tospovirus and one of the most destructive plant viruses. Eight known tospoviruses, Alstroemeria necrotic streak virus (ANSV), Chrysanthemum stem necrosis virus (CSNV), Groundnut ringspot virus (GRSV), Impatiens necrotic spot virus (INSV), Melon severe mosaic virus (MeSMV), Pepper necrotic spot virus (PNSV), Tomato chlorotic spot virus (TCSV) and Zucchini lethal chlorosis virus (ZLCV), sharing serological relatedness with TSWV in NP, are grouped in the TSWV serogroup. Most of the TSWV-serogroup viruses prevail in Europe and America. An efficient diagnostic method is necessary for inspecting these tospoviruses in Asia, including Taiwan. A microarray platform was developed for simultaneous detection and identification of TSWV-serogroup tospoviruses. Total RNAs extracted from Chenopodium quinoa leaves separately inoculated with ANSV, CSNV, GRSV, INSV, TCSV and TSWV were used for testing purposes. The 5'-biotinylated degenerate forward and reverse primers were designed from the consensus sequences of N genes of TSWV-serogroup tospoviruses for reverse transcription-polymerase chain reaction (RT-PCR) amplification. Virus-specific oligonucleotide probes were spotted on the surface of polyvinyl chloride (PVC) chips to hybridize with PCR products. The hybridization signals were visualized by hydrolysis of NBT/BCIP with streptavidine-conjugated alkaline phosphatase. The

  15. Robust Microarray Image Processing

    OpenAIRE

    Novikov, Eugene; Barillot, Emmanuel

    2007-01-01

    In this work we have presented a complete solution for robust, high-throughput, two-color microarray image processing comprising procedures for automatic spot localization, spot quantification and spot quality control. The spot localization algorithm is fully automatic and robust with respect to deviations from perfect spot alignment and contamination. As an input, it requires only the common array design parameters: number of blocks and number of spots in the x and y directions of the array....

  16. [Construction and characterization of normalized cDNA library of maize inbred Mo17 from multiple tissues and developmental stages].

    Science.gov (United States)

    Zhang, Z X; Zhang, F D; Tang, W H; Pi, Y J; Zheng, Y L

    2005-01-01

    Comprehensive complementary DNA (cDNA) library is a valuable resource for functional genomics. In this study, we set up a normalized cDNA library of Mo17 (MONL) by saturation hybridization with genomic DNA, which contained expressed genes of eight tissues and organs from inbred Mo17 of maize (Zea mays L.). In this library, the insert sizes range from 0.4 kb to 4 kb and the average size is 1.18 kb. 10.830 clones were spotted on nylon membrane to make a cDNA microarray. Randomly picked 300 clones from the cDNA library were sequenced. The cDNA microarry was hybridized with pooled tissue mRNA probes or housekeeping gene cDNA probes. The results showed the normalized cDNA library comprehensively includes tissue-specific genes in which 71% are unique ESTs (expressed sequence tags) based on the 300 sequences analyzed. Using BLAST program to compare the sequences against online nucleotide databases, 88% sequences were found in ZmDB or NCBI, and 12% sequences were not found in existing nucleotide databases. More than 73% sequences are of unknown function. The library could be extensively used in developing DNA markers, sequencing ESTs, mining new genes, identifying positional cloning and candidate gene, and developing microarrays in maize genomics research.

  17. Differential gene expression in gall midge susceptible rice genotypes revealed by suppressive subtraction hybridization (SSH) cDNA libraries and microarray analysis.

    Science.gov (United States)

    Rawat, Nidhi; Neeraja, Chiruvuri Naga; Nair, Suresh; Bentur, Jagadish S

    2012-12-01

    A major pest of rice, the Asian rice gall midge (Orseolia oryzae Wood-Mason), causes significant yield losses in the rice growing regions throughout Asia. Feeding by the larvae induces susceptible plants to produce nutritive tissue to support growth and development. In order to identify molecular signatures during compatible interactions, genome wide transcriptional profiling was performed using SSH library and microarray technology. Results revealed up-regulation of genes related to primary metabolism, nutrient relocation, cell organization and DNA synthesis. Concomitantly, defense, secondary metabolism and signaling genes were suppressed. Further, real-time PCR validation of a selected set of 20 genes, in three susceptible rice varieties (TN1, Kavya and Suraksha) during the interaction with the respective virulent gall midge biotypes, also revealed variation in gene expression in Kavya as compared to TN1 and Suraksha. These studies showed that virulent insects induced the plants to step up metabolism and transport nutrients to their feeding site and suppressed defense responses. But Kavya rice mounted an elevated defense response during early hours of virulent gall midge infestation, which was over-powered later, resulting in host plant susceptibility.

  18. Miniaturized electrospraying as a technique for the production of microarrays of reproducible micrometer-sized protein spots.

    Science.gov (United States)

    Moerman, R; Frank, J; Marijnissen, J C; Schalkhammer, T G; van Dedem, G W

    2001-05-15

    Electrospraying in a stable cone-jet mode at N m(-1) and conductivities ranging from 0.04 to 2.2 S m(-1) were sprayed at ultralow flow rates ranging from 100 to 300 pL s(-1). The charged jet that emanates from the cone tip breaks up into a spray of charged droplets that are deposited in the form of a uniform spot of 130-350 microm in diameter by spraying during 0.5-3 s at 220-400 microm above a substrate, respectively. After a spot was deposited, spraying was stopped instantaneously by increasing the distance between the capillary tip and the substrate by an additional 100 microm using a computer-controlled x-y-z table. This was immediately followed by a rapid shift of the substrate 400 microm sideways and 100 microm upward, thus causing spraying to resume instantaneously because of the increased electric field strength, which resulted in the deposition of the next spot. It is shown here that spraying of lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6P-DH), and pyruvate kinase (PK) on a liquid layer resulted in the complete preservation of their activities despite the high solution conductivity of 3.3 S m(-1) and high currents ranging from 300 to 500 nA. LDH and PK activities were fully preserved after spraying onto dry aluminum by adding 0.05 M buffer and 0.5 and 1 wt % of trehalose, respectively, to the spray solutions. Electrospraying allows for accurate dispensing of liquid volumes as small as 50 pL. Enzymatic activities of LDH and PK are fully preserved after spraying.

  19. Application of four dyes in gene expression analyses by microarrays

    Directory of Open Access Journals (Sweden)

    van Schooten Frederik J

    2005-07-01

    Full Text Available Abstract Background DNA microarrays are widely used in gene expression analyses. To increase throughput and minimize costs without reducing gene expression data obtained, we investigated whether four mRNA samples can be analyzed simultaneously by applying four different fluorescent dyes. Results Following tests for cross-talk of fluorescence signals, Alexa 488, Alexa 594, Cyanine 3 and Cyanine 5 were selected for hybridizations. For self-hybridizations, a single RNA sample was labelled with all dyes and hybridized on commercial cDNA arrays or on in-house spotted oligonucleotide arrays. Correlation coefficients for all combinations of dyes were above 0.9 on the cDNA array. On the oligonucleotide array they were above 0.8, except combinations with Alexa 488, which were approximately 0.5. Standard deviation of expression differences for replicate spots were similar on the cDNA array for all dye combinations, but on the oligonucleotide array combinations with Alexa 488 showed a higher variation. Conclusion In conclusion, the four dyes can be used simultaneously for gene expression experiments on the tested cDNA array, but only three dyes can be used on the tested oligonucleotide array. This was confirmed by hybridizations of control with test samples, as all combinations returned similar numbers of differentially expressed genes with comparable effects on gene expression.

  20. [Screening of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) by cDNA microarray and influence of overexpression of PAG1 on biologic behavior of human metastatic prostatic cancer cell line in vitro].

    Science.gov (United States)

    Yu, Wen-juan; Wang, Yue-wei; Xie, Zhi-gang; You, Jiang-feng; Wang, Jie-liang; Cui, Xiang-lin; Pei, Fei; Zheng, Jie

    2010-02-01

    To screen for novel gene(s) associated with tumor metastasis, and to investigate the effect of overexpression of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) on the biological behaviors of human prostatic cancer cell line PC-3M-1E8 in vitro. Four cDNA microarrays were constructed using cDNA library of prostatic cancer cells PC-3M-1E8 (high metastatic potential), PC-3M-2B4 (low metastatic potential), lung cancer cells PG-BE1 (high metastatic potential)and PG-LH7 (low metastatic potential)to screen genes which were differentially expressed according to their different metastatic properties. From a battery of differentially expressed genes, PAG1, which was markedly downregulated in both high metastatic sublines of PC-3M and PG was chosen for further investigation. Real-time PCR and Western blot were used to confirm the gene expression of PAG1 at mRNA and protein levels. Full-length coding sequence of human PAG1 was subcloned into plasmid pcDNA3.0 and the recombinant plasmids were stably transfected into PC-3M-1E8. The cell proliferation ability, anchorage-independent growth, cell cycle distribution, apoptosis rates and invasive ability were detected by MTT, and in addition, soft agar colony formation, flow cytometry analysis and matrigel invasion assay using Boyden chamber were also carried out respectively. All experiments contained pcDNA3.0-PAG1-transfected clones, vector transfected clones and non-transfected parental cells. A total of 327 differentially expressed genes were obtained between the high and low metastatic sublines of PC-3M cells, including 123 upregulated and 204 downregulated genes in PC-3M-1E8. A total of 281 genes, including 167 upregulated and 114 downregulated genes were obtained in PG-BE1 cells. Nine genes were simultaneously downregulated and 8 genes were upregulated in both high metastatic cell lines of PC-3M and PG. The expression of PAG1 at mRNA and protein level were decreased in the high metastatic subline PC-3M-1

  1. A probabilistic framework for microarray data analysis: fundamental probability models and statistical inference.

    Science.gov (United States)

    Ogunnaike, Babatunde A; Gelmi, Claudio A; Edwards, Jeremy S

    2010-05-21

    Gene expression studies generate large quantities of data with the defining characteristic that the number of genes (whose expression profiles are to be determined) exceed the number of available replicates by several orders of magnitude. Standard spot-by-spot analysis still seeks to extract useful information for each gene on the basis of the number of available replicates, and thus plays to the weakness of microarrays. On the other hand, because of the data volume, treating the entire data set as an ensemble, and developing theoretical distributions for these ensembles provides a framework that plays instead to the strength of microarrays. We present theoretical results that under reasonable assumptions, the distribution of microarray intensities follows the Gamma model, with the biological interpretations of the model parameters emerging naturally. We subsequently establish that for each microarray data set, the fractional intensities can be represented as a mixture of Beta densities, and develop a procedure for using these results to draw statistical inference regarding differential gene expression. We illustrate the results with experimental data from gene expression studies on Deinococcus radiodurans following DNA damage using cDNA microarrays. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Carbohydrate microarrays

    DEFF Research Database (Denmark)

    Park, Sungjin; Gildersleeve, Jeffrey C; Blixt, Klas Ola

    2012-01-01

    In the last decade, carbohydrate microarrays have been core technologies for analyzing carbohydrate-mediated recognition events in a high-throughput fashion. A number of methods have been exploited for immobilizing glycans on the solid surface in a microarray format. This microarray-based technol......In the last decade, carbohydrate microarrays have been core technologies for analyzing carbohydrate-mediated recognition events in a high-throughput fashion. A number of methods have been exploited for immobilizing glycans on the solid surface in a microarray format. This microarray......-based technology has been widely employed for rapid analysis of the glycan binding properties of lectins and antibodies, the quantitative measurements of glycan-protein interactions, detection of cells and pathogens, identification of disease-related anti-glycan antibodies for diagnosis, and fast assessment...

  3. Direct calibration of PICKY-designed microarrays

    Directory of Open Access Journals (Sweden)

    Ronald Pamela C

    2009-10-01

    Full Text Available Abstract Background Few microarrays have been quantitatively calibrated to identify optimal hybridization conditions because it is difficult to precisely determine the hybridization characteristics of a microarray using biologically variable cDNA samples. Results Using synthesized samples with known concentrations of specific oligonucleotides, a series of microarray experiments was conducted to evaluate microarrays designed by PICKY, an oligo microarray design software tool, and to test a direct microarray calibration method based on the PICKY-predicted, thermodynamically closest nontarget information. The complete set of microarray experiment results is archived in the GEO database with series accession number GSE14717. Additional data files and Perl programs described in this paper can be obtained from the website http://www.complex.iastate.edu under the PICKY Download area. Conclusion PICKY-designed microarray probes are highly reliable over a wide range of hybridization temperatures and sample concentrations. The microarray calibration method reported here allows researchers to experimentally optimize their hybridization conditions. Because this method is straightforward, uses existing microarrays and relatively inexpensive synthesized samples, it can be used by any lab that uses microarrays designed by PICKY. In addition, other microarrays can be reanalyzed by PICKY to obtain the thermodynamically closest nontarget information for calibration.

  4. Restriction landmark cDNA scanning (RLCS): a novel cDNA display system using two-dimensional gel electrophoresis.

    Science.gov (United States)

    Suzuki, H; Yaoi, T; Kawai, J; Hara, A; Kuwajima, G; Wantanabe, S

    1996-01-01

    We have developed a new method, designated restriction landmark cDNA scanning (RLCS), which displays many cDNA species quantitatively and simultaneously as two-dimensional gel spots. In this method cDNA species of uniform length were prepared for each mRNA species using restriction enzymes. After the restriction enzyme sites were radiolabeled as landmarks, the labeled fragments were subjected to high resolution two-dimensional gel electrophoresis. In analyses of cDNA samples from adult mouse liver and brain (cerebral cortex, cerebellum and brain stem) we detected approximately 500 and >1000 discrete gel spots respectively of various intensities at a time. The spot patterns of the three brain regions were very similar, although not identical, but were quite different from the pattern for the liver. RNA blot hybridization analysis using several cloned spot DNAs as probes showed that differences in intensity of the spots among RLCS profiles correlated well with expression levels of the corresponding mRNA species in the brain regions. Because the spots and their intensities reflect distinct mRNA species and their expression level respectively, the RLCS is a novel cDNA display system which provides a great deal of information and should be useful for systematic documentation of differentially expressed genes. PMID:8628652

  5. Microarray analysis of adipose tissue gene expression profiles ...

    Indian Academy of Sciences (India)

    Excessive accumulation of lipids in the adipose tissue is one of the main problems faced by the broiler industry nowadays. In order to visualize the mechanisms involved in the gene expression and regulation of lipid metabolism in adipose tissue, cDNA microarray containing 9 024 cDNA was used to construct gene ...

  6. Normalization and gene p-value estimation: issues in microarray data processing.

    Science.gov (United States)

    Fundel, Katrin; Küffner, Robert; Aigner, Thomas; Zimmer, Ralf

    2008-05-28

    Numerous methods exist for basic processing, e.g. normalization, of microarray gene expression data. These methods have an important effect on the final analysis outcome. Therefore, it is crucial to select methods appropriate for a given dataset in order to assure the validity and reliability of expression data analysis. Furthermore, biological interpretation requires expression values for genes, which are often represented by several spots or probe sets on a microarray. How to best integrate spot/probe set values into gene values has so far been a somewhat neglected problem. We present a case study comparing different between-array normalization methods with respect to the identification of differentially expressed genes. Our results show that it is feasible and necessary to use prior knowledge on gene expression measurements to select an adequate normalization method for the given data. Furthermore, we provide evidence that combining spot/probe set p-values into gene p-values for detecting differentially expressed genes has advantages compared to combining expression values for spots/probe sets into gene expression values. The comparison of different methods suggests to use Stouffer's method for this purpose. The study has been conducted on gene expression experiments investigating human joint cartilage samples of osteoarthritis related groups: a cDNA microarray (83 samples, four groups) and an Affymetrix (26 samples, two groups) data set. The apparently straight forward steps of gene expression data analysis, e.g. between-array normalization and detection of differentially regulated genes, can be accomplished by numerous different methods. We analyzed multiple methods and the possible effects and thereby demonstrate the importance of the single decisions taken during data processing. We give guidelines for evaluating normalization outcomes. An overview of these effects via appropriate measures and plots compared to prior knowledge is essential for the biological

  7. Gene Expression Analysis Using Agilent DNA Microarrays

    DEFF Research Database (Denmark)

    Stangegaard, Michael

    2009-01-01

    Hybridization of labeled cDNA to microarrays is an intuitively simple and a vastly underestimated process. If it is not performed, optimized, and standardized with the same attention to detail as e.g., RNA amplification, information may be overlooked or even lost. Careful balancing of the amount...

  8. MICROARRAY IMAGE GRIDDING USING GRID LINE REFINEMENT TECHNIQUE

    Directory of Open Access Journals (Sweden)

    V.G. Biju

    2015-05-01

    Full Text Available An important stage in microarray image analysis is gridding. Microarray image gridding is done to locate sub arrays in a microarray image and find co-ordinates of spots within each sub array. For accurate identification of spots, most of the proposed gridding methods require human intervention. In this paper a fully automatic gridding method which enhances spot intensity in the preprocessing step as per a histogram based threshold method is used. The gridding step finds co-ordinates of spots from horizontal and vertical profile of the image. To correct errors due to the grid line placement, a grid line refinement technique is proposed. The algorithm is applied on different image databases and results are compared based on spot detection accuracy and time. An average spot detection accuracy of 95.06% depicts the proposed method’s flexibility and accuracy in finding the spot co-ordinates for different database images.

  9. QUANTITATIVE PROTEOMICS OF THE ARCHAEON METHANOCOCCUS MARIPALUDIS VALIDATED BY MICROARRAY ANALYSIS AND REAL TIME PCR

    Science.gov (United States)

    Xia, Qiangwei; Hendrickson, Erik L.; Zhang, Yi; Wang, Tiansong; Taub, Fred; Moore, Brian C.; Porat, Iris; Whitman, William B.; Hackett, Murray; Leigh, John A.

    2009-01-01

    SUMMARY For the archaeon Methanococcus maripaludis, a fully sequenced and annotated model species of hydrogenotrophic methanogen, we report validation of quantitative protein level expression ratios on a proteome-wide basis. Using an approach based on quantitative multidimensional capillary HPLC and quadrupole ion trap mass spectrometry, coverage of gene expression approached that currently achievable with transcription microarrays. Comprehensive mass-spectrometry-based proteomics and spotted cDNA arrays were used to compare global protein and mRNA levels in a wild-type (S2) and mutant strain (S40) of M. maripaludis. Using linear regression with 652 expression ratios generated by both the proteomic and microarray methods, a product moment correlation coefficient of 0.24 was observed. The correlation improved to 0.61 if only genes showing significant expression changes were included. A novel two-stage method of outlier detection was employed for the protein measurements when Dixon’s Q-test by itself failed to give satisfactory results. The log2 transformations of the number of peptides or isotopic peptide pairs associated with each ORF, divided by the predicted molecular weight, were found to have moderately positive correlations with two bioinformatic predictors of gene expression based on codon bias. We detected peptides derived from 939 proteins or 55% of the genome coding capacity. Of these, 60 were over-expressed and 34 were under-expressed in the mutant. Of the 1722 ORFs encoded in the genome, 1597 or 93% were probed by cDNA arrays. Of these, 50 were more highly expressed and 45 showed lower expression levels in the mutant relative to the wild-type. 15 ORFs were shown to be over-expressed by both methods and 2 ORFs were shown to be over-expressed by proteomics and under-expressed by microarray. PMID:16489187

  10. DNA Microarrays

    Science.gov (United States)

    Nguyen, C.; Gidrol, X.

    Genomics has revolutionised biological and biomedical research. This revolution was predictable on the basis of its two driving forces: the ever increasing availability of genome sequences and the development of new technology able to exploit them. Up until now, technical limitations meant that molecular biology could only analyse one or two parameters per experiment, providing relatively little information compared with the great complexity of the systems under investigation. This gene by gene approach is inadequate to understand biological systems containing several thousand genes. It is essential to have an overall view of the DNA, RNA, and relevant proteins. A simple inventory of the genome is not sufficient to understand the functions of the genes, or indeed the way that cells and organisms work. For this purpose, functional studies based on whole genomes are needed. Among these new large-scale methods of molecular analysis, DNA microarrays provide a way of studying the genome and the transcriptome. The idea of integrating a large amount of data derived from a support with very small area has led biologists to call these chips, borrowing the term from the microelectronics industry. At the beginning of the 1990s, the development of DNA chips on nylon membranes [1, 2], then on glass [3] and silicon [4] supports, made it possible for the first time to carry out simultaneous measurements of the equilibrium concentration of all the messenger RNA (mRNA) or transcribed RNA in a cell. These microarrays offer a wide range of applications, in both fundamental and clinical research, providing a method for genome-wide characterisation of changes occurring within a cell or tissue, as for example in polymorphism studies, detection of mutations, and quantitative assays of gene copies. With regard to the transcriptome, it provides a way of characterising differentially expressed genes, profiling given biological states, and identifying regulatory channels.

  11. Normalizing cDNA libraries.

    Science.gov (United States)

    Bogdanov, Ekaterina A; Shagina, Irina; Barsova, Ekaterina V; Kelmanson, Ilya; Shagin, Dmitry A; Lukyanov, Sergey A

    2010-04-01

    The characterization of rare messages in cDNA libraries is complicated by the substantial variations that exist in the abundance levels of different transcripts in cells and tissues. The equalization (normalization) of cDNA is a helpful approach for decreasing the prevalence of abundant transcripts, thereby facilitating the assessment of rare transcripts. This unit provides a method for duplex-specific nuclease (DSN)-based normalization, which allows for the fast and reliable equalization of cDNA, thereby facilitating the generation of normalized, full-length-enriched cDNA libraries, and enabling efficient RNA analyses. (c) 2010 by John Wiley & Sons, Inc.

  12. Segmentation and intensity estimation of microarray images using a gamma-t mixture model.

    Science.gov (United States)

    Baek, Jangsun; Son, Young Sook; McLachlan, Geoffrey J

    2007-02-15

    use of the bivariate t distribution for the foreground intensity provides a model that is less sensitive to extreme observations; (5) as a consequence of the aforementioned properties, it allows segmentation to be undertaken for a wide range of spot shapes, including doughnut, sickle shape and artifacts. We apply our method for gridding, segmentation and estimation to cDNA microarray real images and artificial data. Our method provides better segmentation results in spot shapes as well as intensity estimation than Spot and spotSegmentation R language softwares. It detected blank spots as well as bright artifact for the real data, and estimated spot intensities with high-accuracy for the synthetic data. The algorithms were implemented in Matlab. The Matlab codes implementing both the gridding and segmentation/estimation are available upon request. Supplementary material is available at Bioinformatics online.

  13. Microarray-integrated optoelectrofluidic immunoassay system.

    Science.gov (United States)

    Han, Dongsik; Park, Je-Kyun

    2016-05-01

    A microarray-based analytical platform has been utilized as a powerful tool in biological assay fields. However, an analyte depletion problem due to the slow mass transport based on molecular diffusion causes low reaction efficiency, resulting in a limitation for practical applications. This paper presents a novel method to improve the efficiency of microarray-based immunoassay via an optically induced electrokinetic phenomenon by integrating an optoelectrofluidic device with a conventional glass slide-based microarray format. A sample droplet was loaded between the microarray slide and the optoelectrofluidic device on which a photoconductive layer was deposited. Under the application of an AC voltage, optically induced AC electroosmotic flows caused by a microarray-patterned light actively enhanced the mass transport of target molecules at the multiple assay spots of the microarray simultaneously, which reduced tedious reaction time from more than 30 min to 10 min. Based on this enhancing effect, a heterogeneous immunoassay with a tiny volume of sample (5 μl) was successfully performed in the microarray-integrated optoelectrofluidic system using immunoglobulin G (IgG) and anti-IgG, resulting in improved efficiency compared to the static environment. Furthermore, the application of multiplex assays was also demonstrated by multiple protein detection.

  14. A wavelet-based Markov random field segmentation model in segmenting microarray experiments.

    Science.gov (United States)

    Athanasiadis, Emmanouil; Cavouras, Dionisis; Kostopoulos, Spyros; Glotsos, Dimitris; Kalatzis, Ioannis; Nikiforidis, George

    2011-12-01

    In the present study, an adaptation of the Markov Random Field (MRF) segmentation model, by means of the stationary wavelet transform (SWT), applied to complementary DNA (cDNA) microarray images is proposed (WMRF). A 3-level decomposition scheme of the initial microarray image was performed, followed by a soft thresholding filtering technique. With the inverse process, a Denoised image was created. In addition, by using the Amplitudes of the filtered wavelet Horizontal and Vertical images at each level, three different Magnitudes were formed. These images were combined with the Denoised one to create the proposed SMRF segmentation model. For numerical evaluation of the segmentation accuracy, the segmentation matching factor (SMF), the Coefficient of Determination (r(2)), and the concordance correlation (p(c)) were calculated on the simulated images. In addition, the SMRF performance was contrasted to the Fuzzy C Means (FCM), Gaussian Mixture Models (GMM), Fuzzy GMM (FGMM), and the conventional MRF techniques. Indirect accuracy performances were also tested on the experimental images by means of the Mean Absolute Error (MAE) and the Coefficient of Variation (CV). In the latter case, SPOT and SCANALYZE software results were also tested. In the former case, SMRF attained the best SMF, r(2), and p(c) (92.66%, 0.923, and 0.88, respectively) scores, whereas, in the latter case scored MAE and CV, 497 and 0.88, respectively. The results and support the performance superiority of the SMRF algorithm in segmenting cDNA images. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. cDNA library preparation.

    Science.gov (United States)

    Kooiker, Maarten; Xue, Gang-Ping

    2014-01-01

    The construction of full-length cDNA libraries allows researchers to study gene expression and protein interactions and undertake gene discovery. Recent improvements allow the construction of high-quality cDNA libraries, with small amounts of mRNA. In parallel, these improvements allow for the incorporation of adapters into the cDNA, both at the 5' and 3' end of the cDNA. The 3' adapter is attached to the oligo-dT primer that is used by the reverse transcriptase, whereas the 5' adapter is incorporated by the template switching properties of the MMLV reverse transcriptase. This allows directional cloning and eliminates inefficient steps like adapter ligation, phosphorylation, and methylation. Another important step in the construction of high-quality cDNA libraries is the normalization. The difference in the levels of expression between genes might be several orders of magnitude. Therefore, it is essential that the cDNA library is normalized. With a recently discovered enzyme, duplex-specific nuclease, it is possible to normalize the cDNA library, based on the fact that more abundant molecules are more likely to reanneal after denaturation compared to rare molecules.

  16. Normalized cDNA libraries

    Science.gov (United States)

    Soares, Marcelo B.; Efstratiadis, Argiris

    1997-01-01

    This invention provides a method to normalize a directional cDNA library constructed in a vector that allows propagation in single-stranded circle form comprising: (a) propagating the directional cDNA library in single-stranded circles; (b) generating fragments complementary to the 3' noncoding sequence of the single-stranded circles in the library to produce partial duplexes; (c) purifying the partial duplexes; (d) melting and reassociating the purified partial duplexes to moderate Cot; and (e) purifying the unassociated single-stranded circles, thereby generating a normalized cDNA library.

  17. Advancing microarray assembly with acoustic dispensing technology.

    Science.gov (United States)

    Wong, E Y; Diamond, S L

    2009-01-01

    In the assembly of microarrays and microarray-based chemical assays and enzymatic bioassays, most approaches use pins for contact spotting. Acoustic dispensing is a technology capable of nanoliter transfers by using acoustic energy to eject liquid sample from an open source well. Although typically used for well plate transfers, when applied to microarraying, it avoids the drawbacks of undesired physical contact with the sample; difficulty in assembling multicomponent reactions on a chip by readdressing, a rigid mode of printing that lacks patterning capabilities; and time-consuming wash steps. We demonstrated the utility of acoustic dispensing by delivering human cathepsin L in a drop-on-drop fashion into individual 50-nanoliter, prespotted reaction volumes to activate enzyme reactions at targeted positions on a microarray. We generated variable-sized spots ranging from 200 to 750 microm (and higher) and handled the transfer of fluorescent bead suspensions with increasing source well concentrations of 0.1 to 10 x 10(8) beads/mL in a linear fashion. There are no tips that can clog, and liquid dispensing CVs are generally below 5%. This platform expands the toolbox for generating analytical arrays and meets needs associated with spatially addressed assembly of multicomponent microarrays on the nanoliter scale.

  18. Hybridization and Selective Release of DNA Microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Beer, N R; Baker, B; Piggott, T; Maberry, S; Hara, C M; DeOtte, J; Benett, W; Mukerjee, E; Dzenitis, J; Wheeler, E K

    2011-11-29

    DNA microarrays contain sequence specific probes arrayed in distinct spots numbering from 10,000 to over 1,000,000, depending on the platform. This tremendous degree of multiplexing gives microarrays great potential for environmental background sampling, broad-spectrum clinical monitoring, and continuous biological threat detection. In practice, their use in these applications is not common due to limited information content, long processing times, and high cost. The work focused on characterizing the phenomena of microarray hybridization and selective release that will allow these limitations to be addressed. This will revolutionize the ways that microarrays can be used for LLNL's Global Security missions. The goals of this project were two-fold: automated faster hybridizations and selective release of hybridized features. The first study area involves hybridization kinetics and mass-transfer effects. the standard hybridization protocol uses an overnight incubation to achieve the best possible signal for any sample type, as well as for convenience in manual processing. There is potential to significantly shorten this time based on better understanding and control of the rate-limiting processes and knowledge of the progress of the hybridization. In the hybridization work, a custom microarray flow cell was used to manipulate the chemical and thermal environment of the array and autonomously image the changes over time during hybridization. The second study area is selective release. Microarrays easily generate hybridization patterns and signatures, but there is still an unmet need for methodologies enabling rapid and selective analysis of these patterns and signatures. Detailed analysis of individual spots by subsequent sequencing could potentially yield significant information for rapidly mutating and emerging (or deliberately engineered) pathogens. In the selective release work, optical energy deposition with coherent light quickly provides the thermal energy

  19. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  20. Microarray image segmentation using additional dye--an experimental study.

    Science.gov (United States)

    Gupta, Rashi; Ruosaari, Salla; Kulathinal, Sangita; Hollmén, Jaakko; Auvinen, Petri

    2007-01-01

    The DNA microarray technique allows monitoring the expression levels of thousands of genes simultaneously. A single DNA microarray experiment involves a number of error-prone manual and automated processes, which influence the results and have an impact on the subsequent stages of analysis. Typical problems of arrays are pinning errors while probe printing and the corruption of spots by noise patches. These errors should be detected at the time of image analysis in order to prevent the erroneous intensities from ending up in the analysis and inference stages. In this paper we introduce the concept (referred to as SybrSpot) of utilizing information provided by an additional dye, SYBR green RNA II, for segmentation of gene expression microarrays. Owing to the effective binding of the SYBR green RNA II to the array probes, an image with high signal-to-noise ratio is obtained. This image is used to learn about the spot quality and to flag spots which are not reliably hybridized and corrupted by noise. Further, we compare SybrSpot with GenePix and demonstrate that SybrSpot performs better than GenePix when flagging spots with no probes or weak probes. The code is available upon request to authors.

  1. cDNA amplification by SMART-PCR and suppression subtractive hybridization (SSH)-PCR.

    Science.gov (United States)

    Hillmann, Andrew; Dunne, Eimear; Kenny, Dermot

    2009-01-01

    The comparison of two RNA populations that differ from the effects of a single-independent variable, such as a drug treatment or a specific genetic defect, can identify differences in the abundance of specific transcripts that vary in a population-dependent manner. There are a variety of methods for identifying differentially expressed genes, including microarray, SAGE, qRT-PCR, and DDGE. This protocol describes a potentially less sensitive yet relatively easy and cost-effective alternative that does not require prior knowledge of the transcriptomes under investigation and is particularly applicable when minimal levels of starting material, RNA, are available. RNA input can often be a limiting factor when analyzing RNA from, for example, rigorously purified blood cells. This protocol describes the use of SMART-PCR to amplify cDNA from sub-microgram levels of RNA. The amplified cDNA populations under comparison are then subjected to suppression subtractive hybridization (SSH-PCR), a technique that couples subtractive hybridization with suppression PCR to selectively amplify fragments of differentially expressed genes. The final products are cDNA populations enriched for significantly over-represented transcripts in either of the two input RNA preparations. These cDNA populations may then be cloned to make subtracted cDNA libraries and/or used as probes to screen subtracted cDNA, global cDNA, or genomic DNA libraries.

  2. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  3. DNA Microarray Technology

    Science.gov (United States)

    ... this page. En Español: Tecnología de micromatriz de ADN DNA Microarray Technology What is a DNA microarray? ... this page. En Español: Tecnología de micromatriz de ADN Get Email Updates Privacy Copyright Contact Accessibility Plug- ...

  4. Characterization of a tailless white spot syndrome virus from ...

    African Journals Online (AJOL)

    Jane

    2011-10-17

    Oct 17, 2011 ... interactions between WSSV and their hosts, a variety of approaches have been used, including mRNA differential display technique (Astrofsky et al., 2002), differential hybridization (He et al., 2005), cDNA microarrays (Dhar et al., 2003; Wang et al., 2006), suppression subtractive hybridization (SSH) (Pan et ...

  5. Dark Spots

    Science.gov (United States)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  6. Universal Reference RNA as a standard for microarray experiments

    Directory of Open Access Journals (Sweden)

    Fero Michael

    2004-03-01

    Full Text Available Abstract Background Obtaining reliable and reproducible two-color microarray gene expression data is critically important for understanding the biological significance of perturbations made on a cellular system. Microarray design, RNA preparation and labeling, hybridization conditions and data acquisition and analysis are variables difficult to simultaneously control. A useful tool for monitoring and controlling intra- and inter-experimental variation is Universal Reference RNA (URR, developed with the goal of providing hybridization signal at each microarray probe location (spot. Measuring signal at each spot as the ratio of experimental RNA to reference RNA targets, rather than relying on absolute signal intensity, decreases variability by normalizing signal output in any two-color hybridization experiment. Results Human, mouse and rat URR (UHRR, UMRR and URRR, respectively were prepared from pools of RNA derived from individual cell lines representing different tissues. A variety of microarrays were used to determine percentage of spots hybridizing with URR and producing signal above a user defined threshold (microarray coverage. Microarray coverage was consistently greater than 80% for all arrays tested. We confirmed that individual cell lines contribute their own unique set of genes to URR, arguing for a pool of RNA from several cell lines as a better configuration for URR as opposed to a single cell line source for URR. Microarray coverage comparing two separately prepared batches each of UHRR, UMRR and URRR were highly correlated (Pearson's correlation coefficients of 0.97. Conclusion Results of this study demonstrate that large quantities of pooled RNA from individual cell lines are reproducibly prepared and possess diverse gene representation. This type of reference provides a standard for reducing variation in microarray experiments and allows more reliable comparison of gene expression data within and between experiments and

  7. A genome-wide 20 K citrus microarray for gene expression analysis

    Directory of Open Access Journals (Sweden)

    Gadea Jose

    2008-07-01

    Full Text Available Abstract Background Understanding of genetic elements that contribute to key aspects of citrus biology will impact future improvements in this economically important crop. Global gene expression analysis demands microarray platforms with a high genome coverage. In the last years, genome-wide EST collections have been generated in citrus, opening the possibility to create new tools for functional genomics in this crop plant. Results We have designed and constructed a publicly available genome-wide cDNA microarray that include 21,081 putative unigenes of citrus. As a functional companion to the microarray, a web-browsable database 1 was created and populated with information about the unigenes represented in the microarray, including cDNA libraries, isolated clones, raw and processed nucleotide and protein sequences, and results of all the structural and functional annotation of the unigenes, like general description, BLAST hits, putative Arabidopsis orthologs, microsatellites, putative SNPs, GO classification and PFAM domains. We have performed a Gene Ontology comparison with the full set of Arabidopsis proteins to estimate the genome coverage of the microarray. We have also performed microarray hybridizations to check its usability. Conclusion This new cDNA microarray replaces the first 7K microarray generated two years ago and allows gene expression analysis at a more global scale. We have followed a rational design to minimize cross-hybridization while maintaining its utility for different citrus species. Furthermore, we also provide access to a website with full structural and functional annotation of the unigenes represented in the microarray, along with the ability to use this site to directly perform gene expression analysis using standard tools at different publicly available servers. Furthermore, we show how this microarray offers a good representation of the citrus genome and present the usefulness of this genomic tool for global

  8. Fluorescent microarray for multiplexed quantification of environmental contaminants in seawater samples

    Science.gov (United States)

    The development of a fluorescent multiplexed microarray platform able to detect and quantify a wide variety of pollutants in seawater is reported. The microarray platform has been manufactured by spotting 6 different bioconjugate competitors and it uses a cocktail of 6 monoclonal and polyclonal anti...

  9. DNA Microarray Technologies: A Novel Approach to Geonomic Research

    Energy Technology Data Exchange (ETDEWEB)

    Hinman, R.; Thrall, B.; Wong, K,

    2002-01-01

    A cDNA microarray allows biologists to examine the expression of thousands of genes simultaneously. Researchers may analyze the complete transcriptional program of an organism in response to specific physiological or developmental conditions. By design, a cDNA microarray is an experiment with many variables and few controls. One question that inevitably arises when working with a cDNA microarray is data reproducibility. How easy is it to confirm mRNA expression patterns? In this paper, a case study involving the treatment of a murine macrophage RAW 264.7 cell line with tumor necrosis factor alpha (TNF) was used to obtain a rough estimate of data reproducibility. Two trials were examined and a list of genes displaying either a > 2-fold or > 4-fold increase in gene expression was compiled. Variations in signal mean ratios between the two slides were observed. We can assume that erring in reproducibility may be compensated by greater inductive levels of similar genes. Steps taken to obtain results included serum starvation of cells before treatment, tests of mRNA for quality/consistency, and data normalization.

  10. Oligonucleotide microarrays: immobilization of phosphorylated oligonucleotides on epoxylated surface.

    Science.gov (United States)

    Mahajan, S; Kumar, P; Gupta, K C

    2006-01-01

    A facile and efficient method for direct immobilization of phosphorylated oligonucleotides on an epoxy-activated glass surface is described. The new immobilization strategy has been analyzed for its performance in DNA microarray under both microwave and thermal conditions. It reflects high immobilization efficiency ( approximately 23%), and signal-to-noise ratio ( approximately 98) and resulted in high hybridization efficiency ( approximately 36%) in comparison to those obtained with standard methods, viz., NTMTA ( approximately 9.76%) and epoxide-amine ( approximately 9.82%). The probes immobilized through the new strategy were found to be heat-stable, since the performance of microarray decreased by only approximately 7% after subjecting it to 20 PCR-like heat cycles, suggesting that the chemistry could be used in integrated PCR/microarray devices. The immobilization of probes following the proposed chemistry resulted in spots of superior quality in terms of spot morphology, spot homogeneity, and signal reproducibility. The constructed microarrays have been successfully used for the discrimination of nucleotide mismatches. In conclusion, these features make the new immobilization strategy ideal for facile, efficient, and cost-effective manufacturing of DNA microarrays.

  11. Protein microarray: sensitive and effective immunodetection for drug residues

    Directory of Open Access Journals (Sweden)

    Zer Cindy

    2010-02-01

    Full Text Available Abstract Background Veterinary drugs such as clenbuterol (CL and sulfamethazine (SM2 are low molecular weight ( Results The artificial antigens were spotted on microarray slides. Standard concentrations of the compounds were added to compete with the spotted antigens for binding to the antisera to determine the IC50. Our microarray assay showed the IC50 were 39.6 ng/ml for CL and 48.8 ng/ml for SM2, while the traditional competitive indirect-ELISA (ci-ELISA showed the IC50 were 190.7 ng/ml for CL and 156.7 ng/ml for SM2. We further validated the two methods with CL fortified chicken muscle tissues, and the protein microarray assay showed 90% recovery while the ci-ELISA had 76% recovery rate. When tested with CL-fed chicken muscle tissues, the protein microarray assay had higher sensitivity (0.9 ng/g than the ci-ELISA (0.1 ng/g for detection of CL residues. Conclusions The protein microarrays showed 4.5 and 3.5 times lower IC50 than the ci-ELISA detection for CL and SM2, respectively, suggesting that immunodetection of small molecules with protein microarray is a better approach than the traditional ELISA technique.

  12. DNA Microarray Technology; TOPICAL

    International Nuclear Information System (INIS)

    WERNER-WASHBURNE, MARGARET; DAVIDSON, GEORGE S.

    2002-01-01

    Collaboration between Sandia National Laboratories and the University of New Mexico Biology Department resulted in the capability to train students in microarray techniques and the interpretation of data from microarray experiments. These studies provide for a better understanding of the role of stationary phase and the gene regulation involved in exit from stationary phase, which may eventually have important clinical implications. Importantly, this research trained numerous students and is the basis for three new Ph.D. projects

  13. Segmentation and intensity estimation for microarray images with saturated pixels

    Directory of Open Access Journals (Sweden)

    Yang Yan

    2011-11-01

    Full Text Available Abstract Background Microarray image analysis processes scanned digital images of hybridized arrays to produce the input spot-level data for downstream analysis, so it can have a potentially large impact on those and subsequent analysis. Signal saturation is an optical effect that occurs when some pixel values for highly expressed genes or peptides exceed the upper detection threshold of the scanner software (216 - 1 = 65, 535 for 16-bit images. In practice, spots with a sizable number of saturated pixels are often flagged and discarded. Alternatively, the saturated values are used without adjustments for estimating spot intensities. The resulting expression data tend to be biased downwards and can distort high-level analysis that relies on these data. Hence, it is crucial to effectively correct for signal saturation. Results We developed a flexible mixture model-based segmentation and spot intensity estimation procedure that accounts for saturated pixels by incorporating a censored component in the mixture model. As demonstrated with biological data and simulation, our method extends the dynamic range of expression data beyond the saturation threshold and is effective in correcting saturation-induced bias when the lost information is not tremendous. We further illustrate the impact of image processing on downstream classification, showing that the proposed method can increase diagnostic accuracy using data from a lymphoma cancer diagnosis study. Conclusions The presented method adjusts for signal saturation at the segmentation stage that identifies a pixel as part of the foreground, background or other. The cluster membership of a pixel can be altered versus treating saturated values as truly observed. Thus, the resulting spot intensity estimates may be more accurate than those obtained from existing methods that correct for saturation based on already segmented data. As a model-based segmentation method, our procedure is able to identify inner

  14. Mongolian spots

    Directory of Open Access Journals (Sweden)

    Divya Gupta

    2013-01-01

    Full Text Available Mongolian spots (MS are birthmarks that are present at birth and their most common location is sacrococcygeal or lumbar area. Lesions may be single or multiple and usually involve < 5% total body surface area. They are macular and round, oval or irregular in shape. The color varies from blue to greenish, gray, black or a combination of any of the above. The size varies from few to more than 20 centimetres. Pigmentation is most intense at the age of one year and gradually fades thereafter. It is rarely seen after the age of 6 years. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although regarded as benign, recent data suggest that MS may be associated with inborn errors of metabolism and neurocristopathies. Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extrasacral lesions for cosmesis.

  15. Fully Automated Complementary DNA Microarray Segmentation using a Novel Fuzzy-based Algorithm.

    Science.gov (United States)

    Saberkari, Hamidreza; Bahrami, Sheyda; Shamsi, Mousa; Amoshahy, Mohammad Javad; Ghavifekr, Habib Badri; Sedaaghi, Mohammad Hossein

    2015-01-01

    DNA microarray is a powerful approach to study simultaneously, the expression of 1000 of genes in a single experiment. The average value of the fluorescent intensity could be calculated in a microarray experiment. The calculated intensity values are very close in amount to the levels of expression of a particular gene. However, determining the appropriate position of every spot in microarray images is a main challenge, which leads to the accurate classification of normal and abnormal (cancer) cells. In this paper, first a preprocessing approach is performed to eliminate the noise and artifacts available in microarray cells using the nonlinear anisotropic diffusion filtering method. Then, the coordinate center of each spot is positioned utilizing the mathematical morphology operations. Finally, the position of each spot is exactly determined through applying a novel hybrid model based on the principle component analysis and the spatial fuzzy c-means clustering (SFCM) algorithm. Using a Gaussian kernel in SFCM algorithm will lead to improving the quality in complementary DNA microarray segmentation. The performance of the proposed algorithm has been evaluated on the real microarray images, which is available in Stanford Microarray Databases. Results illustrate that the accuracy of microarray cells segmentation in the proposed algorithm reaches to 100% and 98% for noiseless/noisy cells, respectively.

  16. Development of a Digital Microarray with Interferometric Reflectance Imaging

    Science.gov (United States)

    Sevenler, Derin

    This dissertation describes a new type of molecular assay for nucleic acids and proteins. We call this technique a digital microarray since it is conceptually similar to conventional fluorescence microarrays, yet it performs enumerative ('digital') counting of the number captured molecules. Digital microarrays are approximately 10,000-fold more sensitive than fluorescence microarrays, yet maintain all of the strengths of the platform including low cost and high multiplexing (i.e., many different tests on the same sample simultaneously). Digital microarrays use gold nanorods to label the captured target molecules. Each gold nanorod on the array is individually detected based on its light scattering, with an interferometric microscopy technique called SP-IRIS. Our optimized high-throughput version of SP-IRIS is able to scan a typical array of 500 spots in less than 10 minutes. Digital DNA microarrays may have utility in applications where sequencing is prohibitively expensive or slow. As an example, we describe a digital microarray assay for gene expression markers of bacterial drug resistance.

  17. Expression analysis of multiple myeloma CD138 negative progenitor cells using single molecule microarray readout

    Science.gov (United States)

    Jacak, Jaroslaw; Schnidar, Harald; Muresan, Leila; Regl, Gerhard; Frischauf, Annemarie; Aberger, Fritz; Schütz, Gerhard J.; Hesse, Jan

    2013-01-01

    We present a highly sensitive bioanalytical microarray assay that enables the analysis of small genomic sample material. By combining an optimized cDNA purification step with single molecule cDNA detection on the microarray, the platform has improved sensitivity compared to conventional systems, allowing amplification-free determination of expression profiles with as little as 600 ng total RNA. Total RNA from cells was reverse transcribed into fluorescently labeled cDNA and purified employing a precipitation method that minimizes loss of cDNA material. The microarray was scanned on a fluorescence chip-reader with single molecule sensitivity. Using the newly developed platform we were able to analyze the RNA expression profile of a subpopulation of rare multiple myeloma CD138 negative progenitor (MM CD138neg) cells. The high-sensitivity microarray approach led to the identification of a set of 20 genes differentially expressed in MM CD138neg cells. Our work demonstrates the applicability of a straight-forward single-molecule DNA array technology to current topics of molecular and cellular cancer research, which are otherwise difficult to address due to the limited amount of sample material. PMID:23416329

  18. Emerging use of gene expression microarrays in plant physiology.

    Science.gov (United States)

    Wullschleger, Stan D; Difazio, Stephen P

    2003-01-01

    Microarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context of a well-designed experiment, cDNA and oligonucleotide arrays can provide highthroughput, simultaneous analysis of transcript abundance for hundreds, if not thousands, of genes. However, despite widespread acceptance, the use of microarrays as a tool to better understand processes of interest to the plant physiologist is still being explored. To help illustrate current uses of microarrays in the plant sciences, several case studies that we believe demonstrate the emerging application of gene expression arrays in plant physiology were selected from among the many posters and presentations at the 2003 Plant and Animal Genome XI Conference. Based on this survey, microarrays are being used to assess gene expression in plants exposed to the experimental manipulation of air temperature, soil water content and aluminium concentration in the root zone. Analysis often includes characterizing transcript profiles for multiple post-treatment sampling periods and categorizing genes with common patterns of response using hierarchical clustering techniques. In addition, microarrays are also providing insights into developmental changes in gene expression associated with fibre and root elongation in cotton and maize, respectively. Technical and analytical limitations of microarrays are discussed and projects attempting to advance areas of microarray design and data analysis are highlighted. Finally, although much work remains, we conclude that microarrays are a valuable tool for the plant physiologist interested in the characterization and identification of individual genes and gene families with potential application in the fields of agriculture, horticulture and forestry.

  19. Nanotechnologies in protein microarrays.

    Science.gov (United States)

    Krizkova, Sona; Heger, Zbynek; Zalewska, Marta; Moulick, Amitava; Adam, Vojtech; Kizek, Rene

    2015-01-01

    Protein microarray technology became an important research tool for study and detection of proteins, protein-protein interactions and a number of other applications. The utilization of nanoparticle-based materials and nanotechnology-based techniques for immobilization allows us not only to extend the surface for biomolecule immobilization resulting in enhanced substrate binding properties, decreased background signals and enhanced reporter systems for more sensitive assays. Generally in contemporarily developed microarray systems, multiple nanotechnology-based techniques are combined. In this review, applications of nanoparticles and nanotechnologies in creating protein microarrays, proteins immobilization and detection are summarized. We anticipate that advanced nanotechnologies can be exploited to expand promising fields of proteins identification, monitoring of protein-protein or drug-protein interactions, or proteins structures.

  20. Differentially profiling the low-expression transcriptomes of human hepatoma using a novel SSH/microarray approach.

    Science.gov (United States)

    Pan, Yi-Shin; Lee, Yun-Shien; Lee, Yung-Lin; Lee, Wei-Chen; Hsieh, Sen-Yung

    2006-05-31

    The main limitation in performing genome-wide gene-expression profiling is the assay of low-expression genes. Approaches with high throughput and high sensitivity for assaying low-expression transcripts are urgently needed for functional genomic studies. Combination of the suppressive subtractive hybridization (SSH) and cDNA microarray techniques using the subtracted cDNA clones as probes printed on chips has greatly improved the efficiency for fishing out the differentially expressed clones and has been used before. However, it remains tedious and inefficient sequencing works for identifying genes including the great number of redundancy in the subtracted amplicons, and sacrifices the original advantages of high sensitivity of SSH in profiling low-expression transcriptomes. We modified the previous combination of SSH and microarray methods by directly using the subtracted amplicons as targets to hybridize the pre-made cDNA microarrays (named as "SSH/microarray"). mRNA prepared from three pairs of hepatoma and non-hepatoma liver tissues was subjected to the SSH/microarray assays, as well as directly to regular cDNA microarray assays for comparison. As compared to the original SSH and microarray combination assays, the modified SSH/microarray assays allowed for much easier inspection of the subtraction efficiency and identification of genes in the subtracted amplicons without tedious and inefficient sequencing work. On the other hand, 5015 of the 9376 genes originally filtered out by the regular cDNA microarray assays because of low expression became analyzable by the SSH/microarray assays. Moreover, the SSH/microarray assays detected about ten times more (701 vs. 69) HCC differentially expressed genes (at least a two-fold difference and P SSH/microarray approaches resulted in identifying many differentially expressed genes implicated in the regulation of cell cycle, cell death, signal transduction and cell morphogenesis, suggesting the involvement of multi

  1. The Stanford Microarray Database

    Science.gov (United States)

    Sherlock, Gavin; Hernandez-Boussard, Tina; Kasarskis, Andrew; Binkley, Gail; Matese, John C.; Dwight, Selina S.; Kaloper, Miroslava; Weng, Shuai; Jin, Heng; Ball, Catherine A.; Eisen, Michael B.; Spellman, Paul T.; Brown, Patrick O.; Botstein, David; Cherry, J. Michael

    2001-01-01

    The Stanford Microarray Database (SMD) stores raw and normalized data from microarray experiments, and provides web interfaces for researchers to retrieve, analyze and visualize their data. The two immediate goals for SMD are to serve as a storage site for microarray data from ongoing research at Stanford University, and to facilitate the public dissemination of that data once published, or released by the researcher. Of paramount importance is the connection of microarray data with the biological data that pertains to the DNA deposited on the microarray (genes, clones etc.). SMD makes use of many public resources to connect expression information to the relevant biology, including SGD [Ball,C.A., Dolinski,K., Dwight,S.S., Harris,M.A., Issel-Tarver,L., Kasarskis,A., Scafe,C.R., Sherlock,G., Binkley,G., Jin,H. et al. (2000) Nucleic Acids Res., 28, 77–80], YPD and WormPD [Costanzo,M.C., Hogan,J.D., Cusick,M.E., Davis,B.P., Fancher,A.M., Hodges,P.E., Kondu,P., Lengieza,C., Lew-Smith,J.E., Lingner,C. et al. (2000) Nucleic Acids Res., 28, 73–76], Unigene [Wheeler,D.L., Chappey,C., Lash,A.E., Leipe,D.D., Madden,T.L., Schuler,G.D., Tatusova,T.A. and Rapp,B.A. (2000) Nucleic Acids Res., 28, 10–14], dbEST [Boguski,M.S., Lowe,T.M. and Tolstoshev,C.M. (1993) Nature Genet., 4, 332–333] and SWISS-PROT [Bairoch,A. and Apweiler,R. (2000) Nucleic Acids Res., 28, 45–48] and can be accessed at http://genome-www.stanford.edu/microarray. PMID:11125075

  2. Hyperspectral microarray scanning: impact on the accuracy and reliability of gene expression data

    Directory of Open Access Journals (Sweden)

    Martinez M Juanita

    2005-05-01

    Full Text Available Abstract Background Commercial microarray scanners and software cannot distinguish between spectrally overlapping emission sources, and hence cannot accurately identify or correct for emissions not originating from the labeled cDNA. We employed our hyperspectral microarray scanner coupled with multivariate data analysis algorithms that independently identify and quantitate emissions from all sources to investigate three artifacts that reduce the accuracy and reliability of microarray data: skew toward the green channel, dye separation, and variable background emissions. Results Here we demonstrate that several common microarray artifacts resulted from the presence of emission sources other than the labeled cDNA that can dramatically alter the accuracy and reliability of the array data. The microarrays utilized in this study were representative of a wide cross-section of the microarrays currently employed in genomic research. These findings reinforce the need for careful attention to detail to recognize and subsequently eliminate or quantify the presence of extraneous emissions in microarray images. Conclusion Hyperspectral scanning together with multivariate analysis offers a unique and detailed understanding of the sources of microarray emissions after hybridization. This opportunity to simultaneously identify and quantitate contaminant and background emissions in microarrays markedly improves the reliability and accuracy of the data and permits a level of quality control of microarray emissions previously unachievable. Using these tools, we can not only quantify the extent and contribution of extraneous emission sources to the signal, but also determine the consequences of failing to account for them and gain the insight necessary to adjust preparation protocols to prevent such problems from occurring.

  3. Laser direct writing of biomolecule microarrays

    Science.gov (United States)

    Serra, P.; Fernández-Pradas, J. M.; Berthet, F. X.; Colina, M.; Elvira, J.; Morenza, J. L.

    Protein-based biosensors are highly efficient tools for protein detection and identification. The production of these devices requires the manipulation of tiny amounts of protein solutions in conditions preserving their biological properties. In this work, laser induced forward transfer (LIFT) was used for spotting an array of a purified bacterial antigen in order to check the viability of this technique for the production of protein microarrays. A pulsed Nd:YAG laser beam (355 nm wavelength, 10 ns pulse duration) was used to transfer droplets of a solution containing the Treponema pallidum 17 kDa protein antigen on a glass slide. Optical microscopy showed that a regular array of micrometric droplets could be precisely and uniformly spotted onto a solid substrate. Subsequently, it was proved that LIFT deposition of a T. pallidum 17 kDa antigen onto nylon-coated glass slides preserves its antigenic reactivity and diagnostic properties. These results support that LIFT is suitable for the production of protein microarrays and pave the way for future diagnostics applications.

  4. New oligonucleotide microarray for rapid diagnosis of avian viral diseases.

    Science.gov (United States)

    Sultankulova, Kulyaisan T; Kozhabergenov, Nurlan S; Strochkov, Vitaliy M; Burashev, Yerbol D; Shorayeva, Kamshat A; Chervyakova, Olga V; Rametov, Nurkuisa M; Sandybayev, Nurlan T; Sansyzbay, Abylay R; Orynbayev, Mukhit B

    2017-04-05

    We developed a new oligonucleotide microarray comprising 16 identical subarrays for simultaneous rapid detection of avian viruses: avian influenza virus (AIV), Newcastle disease virus (NDV), infection bronchitis virus (IBV), and infectious bursal disease virus (IBDV) in single- and mixed-virus infections. The objective of the study was to develop an oligonucleotide microarray for rapid diagnosis of avian diseases that would be used in the course of mass analysis for routine epidemiological surveillance owing to its ability to test one specimen for several infections. The paper describes the technique for rapid and simultaneous diagnosis of avian diseases such as avian influenza, Newcastle disease, infectious bronchitis and infectious bursal disease with use of oligonucleotide microarray, conditions for hybridization of fluorescent-labelled viral cDNA on the microarray and its specificity tested with use of AIV, NDV, IBV, IBDV strains as well as biomaterials from poultry. Sensitivity and specificity of the developed microarray was evaluated with use of 122 specimens of biological material: 44 cloacal swabs from sick birds and 78 tissue specimens from dead wild and domestic birds, as well as with use of 15 AIV, NDV, IBV and IBDV strains, different in their origin, epidemiological and biological characteristics (RIBSP Microbial Collection). This microarray demonstrates high diagnostic sensitivity (99.16% within 95% CI limits 97.36-100%) and specificity (100%). Specificity of the developed technique was confirmed by direct sequencing of NP and M (AIV), VP2 (IBDV), S1 (IBV), NP (NDV) gene fragments. Diagnostic effectiveness of the developed DNA microarray is 99.18% and therefore it can be used in mass survey for specific detection of AIV, NDV, IBV and IBDV circulating in the region in the course of epidemiological surveillance. Rather simple method for rapid diagnosis of avian viral diseases that several times shortens duration of assay versus classical diagnostic

  5. Radioactive cDNA microarrys for gene expression profiles in antidepressant therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M. S.; Han, B. J.; Cha, J. H.; Ryu, Y. M.; Shin, E. K.; Park, J. H.; Park, Y. H.; Kim, M. K. [Korea University Medical College, Seoul (Korea, Republic of)

    2002-07-01

    Using radioactive cDNA microarray, we investigated a pattern of gene regulation under treatment of antidepressant on patients of depressive disoder. Basic microarray technology was performed as previously described in our research. The bioinformatic selection of human cDNAs, which is specifically designed for psychiatry, neurology, and signal transduction, were arrayed on nylon membranes. Using with 33P-labeled probes, this method provided highly sensitive gene expression profiles of our interest including brain receptors, drug metabolism, and cellular signalings. Gene expression profiles were also classified into several categories in accordance with the gene-regulation of antidepressant. The gene profiles of our interest were significantly up- (16 genes, >2.0 of Z-ratio) or down- (24 genes, <-2.0 of Z ratio) regulated when compared the good responsed group with the bad-responsed one. Consequently, we demonstrated that radioactive human cDNA microarray is highly likely to be an efficient technology for evaluating the gene regulation of antidepressants, such as selective serotonin-reuptake inhibitors (SSRIs), by using high-throughput biotechnology.

  6. Fish 'n' chips: the use of microarrays for aquatic toxicology.

    Science.gov (United States)

    Denslow, Nancy D; Garcia-Reyero, Natàlia; Barber, David S

    2007-03-01

    Gene expression analysis is changing the way that we look at toxicity, allowing toxicologists to perform parallel analyses of entire transcriptomes. While this technology is not as advanced in aquatic toxicology as it is for mammalian models, it has shown promise for determining modes of action, identifying biomarkers and developing "signatures" of chemicals that can be used for field and mixture studies. A major hurdle for the use of microarrays in aquatic toxicology is the lack of sequence information for non-model species. Custom arrays based on gene libraries enriched for genes that are expressed in response to specific contaminants have been used with excellent success for some non-model species, suggesting that this approach will work well for ecotoxicology and spurring on the sequencing of cDNA libraries for species of interest. New sequencing technology and development of repositories for gene expression data will accelerate the use of microarrays in aquatic toxicology. Notwithstanding the preliminary successes that have been achieved even with partial cDNA libraries printed on arrays, ecological samples present elevated challenges for this technology due to the high degree of variation of the samples. Furthermore, recent studies that show nonlinear toxic responses for ecological species underscore the necessity of establishing time and dose dependence of effects on gene expression and comparing these results with traditional markers of toxicity. To realize the full potential of microarrays, researchers must do the experiments required to bridge the gap between the 'omics' technologies and traditional toxicology to demonstrate that microarrays have predictive value in ecotoxicology.

  7. Improving missing value estimation in microarray data with gene ontology.

    Science.gov (United States)

    Tuikkala, Johannes; Elo, Laura; Nevalainen, Olli S; Aittokallio, Tero

    2006-03-01

    Gene expression microarray experiments produce datasets with frequent missing expression values. Accurate estimation of missing values is an important prerequisite for efficient data analysis as many statistical and machine learning techniques either require a complete dataset or their results are significantly dependent on the quality of such estimates. A limitation of the existing estimation methods for microarray data is that they use no external information but the estimation is based solely on the expression data. We hypothesized that utilizing a priori information on functional similarities available from public databases facilitates the missing value estimation. We investigated whether semantic similarity originating from gene ontology (GO) annotations could improve the selection of relevant genes for missing value estimation. The relative contribution of each information source was automatically estimated from the data using an adaptive weight selection procedure. Our experimental results in yeast cDNA microarray datasets indicated that by considering GO information in the k-nearest neighbor algorithm we can enhance its performance considerably, especially when the number of experimental conditions is small and the percentage of missing values is high. The increase of performance was less evident with a more sophisticated estimation method. We conclude that even a small proportion of annotated genes can provide improvements in data quality significant for the eventual interpretation of the microarray experiments. Java and Matlab codes are available on request from the authors. Available online at http://users.utu.fi/jotatu/GOImpute.html.

  8. A Customized DNA Microarray for Microbial Source Tracking ...

    Science.gov (United States)

    It is estimated that more than 160, 000 miles of rivers and streams in the United States are impaired due to the presence of waterborne pathogens. These pathogens typically originate from human and other animal fecal pollution sources; therefore, a rapid microbial source tracking (MST) method is needed to facilitate water quality assessment and impaired water remediation. We report a novel qualitative DNA microarray technology consisting of 453 probes for the detection of general fecal and host-associated bacteria, viruses, antibiotic resistance, and other environmentally relevant genetic indicators. A novel data normalization and reduction approach is also presented to help alleviate false positives often associated with high-density microarray applications. To evaluate the performance of the approach, DNA and cDNA was isolated from swine, cattle, duck, goose and gull fecal reference samples, as well as soiled poultry liter and raw municipal sewage. Based on nonmetric multidimensional scaling analysis of results, findings suggest that the novel microarray approach may be useful for pathogen detection and identification of fecal contamination in recreational waters. The ability to simultaneously detect a large collection of environmentally important genetic indicators in a single test has the potential to provide water quality managers with a wide range of information in a short period of time. Future research is warranted to measure microarray performance i

  9. Reverse transcription using random pentadecamer primers increases yield and quality of resulting cDNA

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Dufva, I.H.; Dufva, Hans Martin

    2006-01-01

    Reverse transcription of RNA is an invaluable method for gene expression analysis by real-time PCR or microarray methods. Random primers of varying lengths were compared with respect to their efficiency of priming reverse transcription reactions. The results showed that l5-nucleotide-long random...... that random pentadecamers can replace random hexamers in reverse transcription reactions on both poly(A) RNA and amplified RNA, resulting in higher cDNA yields and quality....... with cDNA generated with random hexamers. The increased efficiency of priming using random pentadecamers resulted in reverse transcription of > 80% of the template aRNA, while random hexamers induced reverse transcription of only 40% of the template aRNA. This suggests a better coverage...

  10. Cross-platform analysis of cancer microarray data improves gene expression based classification of phenotypes

    Directory of Open Access Journals (Sweden)

    Eils Roland

    2005-11-01

    Full Text Available Abstract Background The extensive use of DNA microarray technology in the characterization of the cell transcriptome is leading to an ever increasing amount of microarray data from cancer studies. Although similar questions for the same type of cancer are addressed in these different studies, a comparative analysis of their results is hampered by the use of heterogeneous microarray platforms and analysis methods. Results In contrast to a meta-analysis approach where results of different studies are combined on an interpretative level, we investigate here how to directly integrate raw microarray data from different studies for the purpose of supervised classification analysis. We use median rank scores and quantile discretization to derive numerically comparable measures of gene expression from different platforms. These transformed data are then used for training of classifiers based on support vector machines. We apply this approach to six publicly available cancer microarray gene expression data sets, which consist of three pairs of studies, each examining the same type of cancer, i.e. breast cancer, prostate cancer or acute myeloid leukemia. For each pair, one study was performed by means of cDNA microarrays and the other by means of oligonucleotide microarrays. In each pair, high classification accuracies (> 85% were achieved with training and testing on data instances randomly chosen from both data sets in a cross-validation analysis. To exemplify the potential of this cross-platform classification analysis, we use two leukemia microarray data sets to show that important genes with regard to the biology of leukemia are selected in an integrated analysis, which are missed in either single-set analysis. Conclusion Cross-platform classification of multiple cancer microarray data sets yields discriminative gene expression signatures that are found and validated on a large number of microarray samples, generated by different laboratories and

  11. Microfluidic Methods for Protein Microarrays

    OpenAIRE

    Hartmann, Michael

    2010-01-01

    Protein microarray technology has an enormous potential for in vitro diagnostics (IVD)1. Miniaturized and parallelized immunoassays are powerful tools to measure dozens of parameters from minute amounts of sample, whilst only requiring small amounts of reagent. Protein microarrays have become well-established research tools in basic and applied research and the first diagnostic products are already released on the market. However, in order for protein microarrays to become broadly accepted to...

  12. The IronChip evaluation package: a package of perl modules for robust analysis of custom microarrays

    Directory of Open Access Journals (Sweden)

    Brazma Alvis

    2010-03-01

    Full Text Available Abstract Background Gene expression studies greatly contribute to our understanding of complex relationships in gene regulatory networks. However, the complexity of array design, production and manipulations are limiting factors, affecting data quality. The use of customized DNA microarrays improves overall data quality in many situations, however, only if for these specifically designed microarrays analysis tools are available. Results The IronChip Evaluation Package (ICEP is a collection of Perl utilities and an easy to use data evaluation pipeline for the analysis of microarray data with a focus on data quality of custom-designed microarrays. The package has been developed for the statistical and bioinformatical analysis of the custom cDNA microarray IronChip but can be easily adapted for other cDNA or oligonucleotide-based designed microarray platforms. ICEP uses decision tree-based algorithms to assign quality flags and performs robust analysis based on chip design properties regarding multiple repetitions, ratio cut-off, background and negative controls. Conclusions ICEP is a stand-alone Windows application to obtain optimal data quality from custom-designed microarrays and is freely available here (see "Additional Files" section and at: http://www.alice-dsl.net/evgeniy.vainshtein/ICEP/

  13. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... execution within boundaries). Moreover, during the execution of the workload, SpotADAPT suggests a redeployment if the current spot instance gets terminated by Amazon or a better deployment becomes possible due to fluctuations of the spot prices. The approach is evaluated using the actual execution times...

  14. Compressive Sensing DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Sheikh Mona A

    2009-01-01

    Full Text Available Compressive sensing microarrays (CSMs are DNA-based sensors that operate using group testing and compressive sensing (CS principles. In contrast to conventional DNA microarrays, in which each genetic sensor is designed to respond to a single target, in a CSM, each sensor responds to a set of targets. We study the problem of designing CSMs that simultaneously account for both the constraints from CS theory and the biochemistry of probe-target DNA hybridization. An appropriate cross-hybridization model is proposed for CSMs, and several methods are developed for probe design and CS signal recovery based on the new model. Lab experiments suggest that in order to achieve accurate hybridization profiling, consensus probe sequences are required to have sequence homology of at least 80% with all targets to be detected. Furthermore, out-of-equilibrium datasets are usually as accurate as those obtained from equilibrium conditions. Consequently, one can use CSMs in applications in which only short hybridization times are allowed.

  15. MIGS-GPU: Microarray Image Gridding and Segmentation on the GPU.

    Science.gov (United States)

    Katsigiannis, Stamos; Zacharia, Eleni; Maroulis, Dimitris

    2017-05-01

    Complementary DNA (cDNA) microarray is a powerful tool for simultaneously studying the expression level of thousands of genes. Nevertheless, the analysis of microarray images remains an arduous and challenging task due to the poor quality of the images that often suffer from noise, artifacts, and uneven background. In this study, the MIGS-GPU [Microarray Image Gridding and Segmentation on Graphics Processing Unit (GPU)] software for gridding and segmenting microarray images is presented. MIGS-GPU's computations are performed on the GPU by means of the compute unified device architecture (CUDA) in order to achieve fast performance and increase the utilization of available system resources. Evaluation on both real and synthetic cDNA microarray images showed that MIGS-GPU provides better performance than state-of-the-art alternatives, while the proposed GPU implementation achieves significantly lower computational times compared to the respective CPU approaches. Consequently, MIGS-GPU can be an advantageous and useful tool for biomedical laboratories, offering a user-friendly interface that requires minimum input in order to run.

  16. D-MaPs - DNA-microarray projects: Web-based software for multi-platform microarray analysis.

    Science.gov (United States)

    Carazzolle, Marcelo F; Herig, Taís S; Deckmann, Ana C; Pereira, Gonçalo A G

    2009-07-01

    The web application D-Maps provides a user-friendly interface to researchers performing studies based on microarrays. The program was developed to manage and process one- or two-color microarray data obtained from several platforms (currently, GeneTAC, ScanArray, CodeLink, NimbleGen and Affymetrix). Despite the availability of many algorithms and many software programs designed to perform microarray analysis on the internet, these usually require sophisticated knowledge of mathematics, statistics and computation. D-maps was developed to overcome the requirement of high performance computers or programming experience. D-Maps performs raw data processing, normalization and statistical analysis, allowing access to the analyzed data in text or graphical format. An original feature presented by D-Maps is GEO (Gene Expression Omnibus) submission format service. The D-MaPs application was already used for analysis of oligonucleotide microarrays and PCR-spotted arrays (one- and two-color, laser and light scanner). In conclusion, D-Maps is a valuable tool for microarray research community, especially in the case of groups without a bioinformatic core.

  17. D-MaPs - DNA-microarray projects: web-based software for multi-platform microarray analysis

    Directory of Open Access Journals (Sweden)

    Marcelo F. Carazzolle

    2009-01-01

    Full Text Available The web application D-Maps provides a user-friendly interface to researchers performing studies based on microarrays. The program was developed to manage and process one- or two-color microarray data obtained from several platforms (currently, GeneTAC, ScanArray, CodeLink, NimbleGen and Affymetrix. Despite the availability of many algorithms and many software programs designed to perform microarray analysis on the internet, these usually require sophisticated knowledge of mathematics, statistics and computation. D-maps was developed to overcome the requirement of high performance computers or programming experience. D-Maps performs raw data processing, normalization and statistical analysis, allowing access to the analyzed data in text or graphical format. An original feature presented by D-Maps is GEO (Gene Expression Omnibus submission format service. The D-MaPs application was already used for analysis of oligonucleotide microarrays and PCR-spotted arrays (one- and two-color, laser and light scanner. In conclusion, D-Maps is a valuable tool for microarray research community, especially in the case of groups without a bioinformatic core.

  18. Enzyme microarrays assembled by acoustic dispensing technology.

    Science.gov (United States)

    Wong, E Y; Diamond, S L

    2008-10-01

    Miniaturizing bioassays to the nanoliter scale for high-throughput screening reduces the consumption of reagents that are expensive or difficult to handle. Through the use of acoustic dispensing technology, nanodroplets containing 10 microM ATP (3 microCi/microL (32)P) and reaction buffer in 10% glycerol were positionally dispensed to the surface of glass slides to form 40-nL compartments (100 droplets/slide) for Pim1 (proviral integration site 1) kinase reactions. The reactions were activated by dispensing 4 nL of various levels of a pyridocarbazolo-cyclopentadienyl ruthenium complex Pim1 inhibitor, followed by dispensing 4 nL of a Pim1 kinase and peptide substrate solution to achieve final concentrations of 150 nM enzyme and 10 microM substrate. The microarray was incubated at 30 degrees C (97% R(h)) for 1.5 h. The spots were then blotted to phosphocellulose membranes to capture phosphorylated substrate. With phosphor imaging to quantify the washed membranes, the assay showed that, for doses of inhibitor from 0.75 to 3 microM, Pim1 was increasingly inhibited. Signal-to-background ratios were as high as 165, and average coefficients of variation for the assay were approximately 20%. Coefficients of variation for dispensing typical working buffers were under 5%. Thus, microarrays assembled by acoustic dispensing are promising as cost-effective tools that can be used in protein assay development.

  19. PCR-based cDNA library construction: general cDNA libraries at the level of a few cells.

    OpenAIRE

    Belyavsky, A; Vinogradova, T; Rajewsky, K

    1989-01-01

    A procedure for the construction of general cDNA libraries is described which is based on the amplification of total cDNA in vitro. The first cDNA strand is synthesized from total RNA using an oligo(dT)-containing primer. After oligo(dG) tailing the total cDNA is amplified by PCR using two primers complementary to oligo(dA) and oligo(dG) ends of the cDNA. For insertion of the cDNA into a vector a controlled trimming of the 3' ends of the cDNA by Klenow enzyme was used. Starting from 10 J558L ...

  20. Identification of Candidate Breast Cancer Susceptibility Genes Using a cDNA Microarray/CGH Approach

    National Research Council Canada - National Science Library

    Godwin, Andrew

    2003-01-01

    ...; the most notorious are the BRCA1 and BRCA2 genes. However, it has become evident that not all (or even the majority) of familial breast cancer families can be attributed to mutations in BRCA1 and BRCA2...

  1. Identification of Candidate Breast Cancer Susceptibility Genes Using a cDNA Microarray/CGH Approach

    National Research Council Canada - National Science Library

    Godwin, Andrew

    2002-01-01

    ...; the most notorious are the BRCAl and BRCA2 genes. However, it has become evident that not all (or even the majority) of familial breast cancer families can be attributed to mutations in BRCAl and BRCA2...

  2. High-throughput screening of suppression subtractive hybridization cDNA libraries using DNA microarray analysis

    CSIR Research Space (South Africa)

    Van den Berg, N

    2004-11-01

    Full Text Available DNAs to the SSH libraries arrayed on glass slides, two values were calculated for each clone, an enrichment ratio 1 (ER1) and an enrichment ratio 2 (ER2). Graphical representation of ER1 and ER2 enabled the identification of clones that were likely to represent up...

  3. DNA Microarray-Based Diagnostics.

    Science.gov (United States)

    Marzancola, Mahsa Gharibi; Sedighi, Abootaleb; Li, Paul C H

    2016-01-01

    The DNA microarray technology is currently a useful biomedical tool which has been developed for a variety of diagnostic applications. However, the development pathway has not been smooth and the technology has faced some challenges. The reliability of the microarray data and also the clinical utility of the results in the early days were criticized. These criticisms added to the severe competition from other techniques, such as next-generation sequencing (NGS), impacting the growth of microarray-based tests in the molecular diagnostic market.Thanks to the advances in the underlying technologies as well as the tremendous effort offered by the research community and commercial vendors, these challenges have mostly been addressed. Nowadays, the microarray platform has achieved sufficient standardization and method validation as well as efficient probe printing, liquid handling and signal visualization. Integration of various steps of the microarray assay into a harmonized and miniaturized handheld lab-on-a-chip (LOC) device has been a goal for the microarray community. In this respect, notable progress has been achieved in coupling the DNA microarray with the liquid manipulation microsystem as well as the supporting subsystem that will generate the stand-alone LOC device.In this chapter, we discuss the major challenges that microarray technology has faced in its almost two decades of development and also describe the solutions to overcome the challenges. In addition, we review the advancements of the technology, especially the progress toward developing the LOC devices for DNA diagnostic applications.

  4. SSHscreen and SSHdb, generic software for microarray based gene discovery: application to the stress response in cowpea.

    Science.gov (United States)

    Coetzer, Nanette; Gazendam, Inge; Oelofse, Dean; Berger, Dave K

    2010-04-01

    Suppression subtractive hybridization is a popular technique for gene discovery from non-model organisms without an annotated genome sequence, such as cowpea (Vigna unguiculata (L.) Walp). We aimed to use this method to enrich for genes expressed during drought stress in a drought tolerant cowpea line. However, current methods were inefficient in screening libraries and management of the sequence data, and thus there was a need to develop software tools to facilitate the process. Forward and reverse cDNA libraries enriched for cowpea drought response genes were screened on microarrays, and the R software package SSHscreen 2.0.1 was developed (i) to normalize the data effectively using spike-in control spot normalization, and (ii) to select clones for sequencing based on the calculation of enrichment ratios with associated statistics. Enrichment ratio 3 values for each clone showed that 62% of the forward library and 34% of the reverse library clones were significantly differentially expressed by drought stress (adjusted p value 88% of the clones in both libraries were derived from rare transcripts in the original tester samples, thus supporting the notion that suppression subtractive hybridization enriches for rare transcripts. A set of 118 clones were chosen for sequencing, and drought-induced cowpea genes were identified, the most interesting encoding a late embryogenesis abundant Lea5 protein, a glutathione S-transferase, a thaumatin, a universal stress protein, and a wound induced protein. A lipid transfer protein and several components of photosynthesis were down-regulated by the drought stress. Reverse transcriptase quantitative PCR confirmed the enrichment ratio values for the selected cowpea genes. SSHdb, a web-accessible database, was developed to manage the clone sequences and combine the SSHscreen data with sequence annotations derived from BLAST and Blast2GO. The self-BLAST function within SSHdb grouped redundant clones together and illustrated that the

  5. DNA microarrays : a molecular cloning manual

    National Research Council Canada - National Science Library

    Sambrook, Joseph; Bowtell, David

    2002-01-01

    .... DNA Microarrays provides authoritative, detailed instruction on the design, construction, and applications of microarrays, as well as comprehensive descriptions of the software tools and strategies...

  6. Gene targeting associated with the radiation sensitivity in squamous cell carcinoma by using microarray analysis

    International Nuclear Information System (INIS)

    Nimura, Yoshinori; Kumagai, Ken; Kouzu, Yoshinao; Higo, Morihiro; Kato, Yoshikuni; Seki, Naohiko; Yamada, Shigeru

    2005-01-01

    In order to identify a set of genes related to radiation sensitivity of squamous cell carcinoma (SCC) and establish a predictive method, we compared expression profiles of radio-sensitive/radio-resistant SCC cell lines, using the in-house cDNA microarray consisting of 2,201 human genes derived from full-length enriched SCC cDNA libraries and the Human oligo chip 30 K (Hitachi Software Engineering). Surviving fractions (SF) after irradiation of heavy iron were calculated by colony formation assay. Three pairs (TE2-TE13, YES5-YES6, and HSC3-HSC2), sensitive (SF1 0.6), were selected for the microarray analysis. The results of cDNA microarray analysis showed that 20 genes in resistant cell lines and 5 genes in sensitive cell lines were up regulated more than 1.5-fold compared with sensitive and resistant cell lines respectively. Fourteen out of 25 genes were confirmed the gene expression profiles by real-time polymerase chain reaction (PCR). Twenty-seven genes identified by Human oligo chip 30 K are candidate for the markers to distinguish radio-sensitive from radio-resistant. These results suggest that the isolated 27 genes are the candidates that might be used as specific molecular markers to predict radiation sensitivity. (author)

  7. Microarray platform for omics analysis

    Science.gov (United States)

    Mecklenburg, Michael; Xie, Bin

    2001-09-01

    Microarray technology has revolutionized genetic analysis. However, limitations in genome analysis has lead to renewed interest in establishing 'omic' strategies. As we enter the post-genomic era, new microarray technologies are needed to address these new classes of 'omic' targets, such as proteins, as well as lipids and carbohydrates. We have developed a microarray platform that combines self- assembling monolayers with the biotin-streptavidin system to provide a robust, versatile immobilization scheme. A hydrophobic film is patterned on the surface creating an array of tension wells that eliminates evaporation effects thereby reducing the shear stress to which biomolecules are exposed to during immobilization. The streptavidin linker layer makes it possible to adapt and/or develop microarray based assays using virtually any class of biomolecules including: carbohydrates, peptides, antibodies, receptors, as well as them ore traditional DNA based arrays. Our microarray technology is designed to furnish seamless compatibility across the various 'omic' platforms by providing a common blueprint for fabricating and analyzing arrays. The prototype microarray uses a microscope slide footprint patterned with 2 by 96 flat wells. Data on the microarray platform will be presented.

  8. Magnetic Scanometric DNA Microarray Detection of Methyl Tertiary Butyl Ether Degrading Bacteria for Environmental Monitoring

    Science.gov (United States)

    Chan, Mei-Lin; Jaramillo, Gerardo; Hristova, Krassimira R.; Horsley, David A.

    2010-01-01

    A magnetoresistive biosensing platform based on a single magnetic tunnel junction (MTJ) scanning probe and DNA microarrays labeled with magnetic particles has been developed to provide an inexpensive, sensitive and reliable detection of DNA. The biosensing platform was demonstrated on a DNA microarray assay for quantifying bacteria capable of degrading methyl tertiary-butyl ether (MTBE), where concentrations as low as 10 pM were detectable. Synthetic probe bacterial DNA was immobilized on a microarray glass slide surface, hybridized with the 48 base pair long biotinylated target DNA and subsequently incubated with streptavidin-coated 2.8 μm diameter magnetic particles. The biosensing platform then makes use of a micron-sized MTJ sensor that was raster scanned across a 3 mm by 5 mm glass slide area to capture the stray magnetic field from the tagged DNA and extract two dimensional magnetic field images of the microarray. The magnetic field output is then averaged over each 100 μm diameter DNA array spot to extract the magnetic spot intensity, analogous to the fluorescence spot intensity used in conventional optical scanners. The magnetic scanning result is compared with results from a commercial laser scanner and particle coverage optical counting to demonstrate the dynamic range and linear sensitivity of the biosensing platform as a potentially inexpensive, sensitive and portable alternative for DNA microarray detection for field applications. PMID:20889328

  9. Lectin cDNA and transgenic plants derived therefrom

    Science.gov (United States)

    Raikhel, Natasha V.

    2000-10-03

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties.

  10. Cloning, sequencing and expression of cDNA encoding growth ...

    Indian Academy of Sciences (India)

    Using polymerase chain reaction (PCR) primers representing the conserved regions of fish GH sequences the 3′ region of catfish GH cDNA (540 bp) was cloned by random amplification of cDNA ends and the clone was used as a probe to isolate recombinant phages carrying the full-length cDNA sequence. The full-length ...

  11. Cloning, sequencing and expression of cDNA encoding growth ...

    Indian Academy of Sciences (India)

    Unknown

    317. 2.4 cDNA sequencing and analysis. The nucleotide sequence of the cloned H. fossilis GH. cDNA was determined by Sanger's dideoxy chain termi- nation method, using Perkin Elmer bigdye terminator kit in an ABI Prism 377 automated DNA sequencer. All other computational analysis of the GH cDNA was done using.

  12. cDNA sequence quality data - Budding yeast cDNA sequencing project | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Budding yeast cDNA sequencing project cDNA sequence quality data Data detail Data name cDNA sequence quality... data DOI 10.18908/lsdba.nbdc00838-003 Description of data contents Phred's quality score. P...tion Download License Update History of This Database Site Policy | Contact Us cDNA sequence quality

  13. MicroArray Facility: a laboratory information management system with extended support for Nylon based technologies

    Directory of Open Access Journals (Sweden)

    Beaudoing Emmanuel

    2006-09-01

    Full Text Available Abstract Background High throughput gene expression profiling (GEP is becoming a routine technique in life science laboratories. With experimental designs that repeatedly span thousands of genes and hundreds of samples, relying on a dedicated database infrastructure is no longer an option. GEP technology is a fast moving target, with new approaches constantly broadening the field diversity. This technology heterogeneity, compounded by the informatics complexity of GEP databases, means that software developments have so far focused on mainstream techniques, leaving less typical yet established techniques such as Nylon microarrays at best partially supported. Results MAF (MicroArray Facility is the laboratory database system we have developed for managing the design, production and hybridization of spotted microarrays. Although it can support the widely used glass microarrays and oligo-chips, MAF was designed with the specific idiosyncrasies of Nylon based microarrays in mind. Notably single channel radioactive probes, microarray stripping and reuse, vector control hybridizations and spike-in controls are all natively supported by the software suite. MicroArray Facility is MIAME supportive and dynamically provides feedback on missing annotations to help users estimate effective MIAME compliance. Genomic data such as clone identifiers and gene symbols are also directly annotated by MAF software using standard public resources. The MAGE-ML data format is implemented for full data export. Journalized database operations (audit tracking, data anonymization, material traceability and user/project level confidentiality policies are also managed by MAF. Conclusion MicroArray Facility is a complete data management system for microarray producers and end-users. Particular care has been devoted to adequately model Nylon based microarrays. The MAF system, developed and implemented in both private and academic environments, has proved a robust solution for

  14. Using microarrays to identify positional candidate genes for QTL: the case study of ACTH response in pigs

    DEFF Research Database (Denmark)

    Jouffe, Vincent; Rowe, Suzanne; Liaubet, Laurence

    2009-01-01

    of 237 differentially expressed cDNA clones in adrenal tissue from two pig breeds, before and after treatment with adrenocorticotropic hormone (ACTH) Microarray studies can supplement QTL studies by suggesting potential candidate genes in the QTL regions, which by themselves are too large to provide...... this with information on published QTL. The starting point is a set of 237 differentially expressed cDNA clones in adrenal tissue from two pig breeds, before and after treatment with adrenocorticotropic hormone (ACTH) Results: Different approaches to localize the differentially expressed (DE) genes to the pig genome...

  15. Structure and expression of the tomato spotted wilt virus genome : a plant-infecting bunyavirus

    NARCIS (Netherlands)

    Kormelink, R.J.M.

    1994-01-01

    This thesis describes studies which are aimed at the elucidation of the genetic organisation and expression strategy of the tomato spotted wilt virus (TSWV) RNA genome.

    Using specific cDNA clones, corresponding to all three genomic RNA segments, the synthesis of virus specific RNA

  16. The Porcelain Crab Transcriptome and PCAD, the Porcelain Crab Microarray and Sequence Database

    Energy Technology Data Exchange (ETDEWEB)

    Tagmount, Abderrahmane; Wang, Mei; Lindquist, Erika; Tanaka, Yoshihiro; Teranishi, Kristen S.; Sunagawa, Shinichi; Wong, Mike; Stillman, Jonathon H.

    2010-01-27

    Background: With the emergence of a completed genome sequence of the freshwater crustacean Daphnia pulex, construction of genomic-scale sequence databases for additional crustacean sequences are important for comparative genomics and annotation. Porcelain crabs, genus Petrolisthes, have been powerful crustacean models for environmental and evolutionary physiology with respect to thermal adaptation and understanding responses of marine organisms to climate change. Here, we present a large-scale EST sequencing and cDNA microarray database project for the porcelain crab Petrolisthes cinctipes. Methodology/Principal Findings: A set of ~;;30K unique sequences (UniSeqs) representing ~;;19K clusters were generated from ~;;98K high quality ESTs from a set of tissue specific non-normalized and mixed-tissue normalized cDNA libraries from the porcelain crab Petrolisthes cinctipes. Homology for each UniSeq was assessed using BLAST, InterProScan, GO and KEGG database searches. Approximately 66percent of the UniSeqs had homology in at least one of the databases. All EST and UniSeq sequences along with annotation results and coordinated cDNA microarray datasets have been made publicly accessible at the Porcelain Crab Array Database (PCAD), a feature-enriched version of the Stanford and Longhorn Array Databases.Conclusions/Significance: The EST project presented here represents the third largest sequencing effort for any crustacean, and the largest effort for any crab species. Our assembly and clustering results suggest that our porcelain crab EST data set is equally diverse to the much larger EST set generated in the Daphnia pulex genome sequencing project, and thus will be an important resource to the Daphnia research community. Our homology results support the pancrustacea hypothesis and suggest that Malacostraca may be ancestral to Branchiopoda and Hexapoda. Our results also suggest that our cDNA microarrays cover as much of the transcriptome as can reasonably be captured in

  17. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  18. Chum-RNA allows preparation of a high-quality cDNA library from a single-cell quantity of mRNA without PCR amplification.

    Science.gov (United States)

    Tougan, Takahiro; Okuzaki, Daisuke; Nojima, Hiroshi

    2008-09-01

    Linear RNA amplification using T7 RNA polymerase is useful in genome-wide analysis of gene expression using DNA microarrays, but exponential amplification using polymerase chain reaction (PCR) is still required for cDNA library preparation from single-cell quantities of RNA. We have designed a small RNA molecule called chum-RNA that has enabled us to prepare a single-cell cDNA library after four rounds of T7-based linear amplification, without using PCR amplification. Chum-RNA drove cDNA synthesis from only 0.49 femtograms of mRNA (730 mRNA molecules) as a substrate, a quantity that corresponds to a minor population of mRNA molecules in a single mammalian cell. Analysis of the independent cDNA clone of this library (6.6 x 10(5) cfu) suggests that 30-fold RNA amplification occurred in each round of the amplification process. The size distribution and representation of mRNAs in the resulting one-cell cDNA library retained its similarity to that of the million-cell cDNA library. The use of chum-RNA might also facilitate reactions involving other DNA/RNA modifying enzymes whose Michaelis constant (K(m)) values are around 1 mM, allowing them to be activated in the presence of only small quantities of substrate.

  19. Interaction of pseudomonas aeruginosa with epithelial cells: identification of differentially regulated genes by expression microarray analysis of human cDNAs

    NARCIS (Netherlands)

    Ichikawa, J. K.; Norris, A.; Bangera, M. G.; Geiss, G. K.; van 't Wout, A. B.; Bumgarner, R. E.; Lory, S.

    2000-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen that plays a major role in lung function deterioration in cystic fibrosis patients. To identify critical host responses during infection, we have used high-density DNA microarrays, consisting of 1,506 human cDNA clones, to monitor gene expression

  20. Construction and characterization of Japanese medaka (Oryzias latipes) hepatic cDNA library and its implementation to biomarker screening in aquatic toxicology.

    Science.gov (United States)

    Pham, Chi Hoa; Park, Kyung Seo; Kim, Byoung Chan; Kim, Han Na; Gu, Man Bock

    2011-10-01

    To strengthen the toxicogenomic study, we constructed a library of hepatic cDNA from Japanese medaka under influence of specific chemical mediated stress responses. Gene expression profile analysis of the cDNA microarrays followed by real time RT-PCR assay were conducted to screen particular biomarkers for 17-beta estradiol (E2), nonylphenol (NP) and 2-chlorophenol (2CP). Information of 1509 high-quality ESTs including 260 new ESTs was added onto GenBank and dbEST. The ESTs were clustered and assembled into 159 contigs and 372 singletons. Among them, 128 contigs and 163 singletons (54.8%) were functionally characterized and 13 UniESTs (2.5%) were hypothetical proteins. Ontology analysis resulting in 282 UniESTs which involved with 2102 GOs and 93 sequences associated with 116 enzyme codes. For each test chemical, two specific biomarkers were selected from the gene expression profiling of microarrays. The expression patterns of the marker genes in real time PCR analysis were consistent with the regulated gene expression patterns in microarrays. The tentative biomarkers showed unique gene expression patterns depending on chemical concentration(s) and exposure duration in real time RT-PCR analysis. The analysis accomplished of the hepatic cDNA library and its information added to genetic and genomic resources could be sufficiently valuable specifically for aquatic toxicity studies. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Merging microarray data, robust feature selection, and predicting prognosis in prostate cancer

    Directory of Open Access Journals (Sweden)

    Kevin R. Coombes

    2006-01-01

    Full Text Available Motivation: Individual microarray studies searching for prognostic biomarkers often have few samples and low statistical power; however, publicly accessible data sets make it possible to combine data across studies.Method: We present a novel approach for combining microarray data across institutions and platforms. We introduce a new algorithm, robust greedy feature selection (RGFS, to select predictive genes.Results: We combined two prostate cancer microarray data sets, confirmed the appropriateness of the approach with the Kolmogorov-Smirnov goodness-of-fit test, and built several predictive models. The best logistic regression model with stepwise forward selection used 7 genes and had a misclassification rate of 31%. Models that combined LDA with different feature selection algorithms had misclassification rates between 19% and 33%, and the sets of genes in the models varied substantially during cross-validation. When we combined RGFS with LDA, the best model used two genes and had a misclassification rate of 15%.Availability: Affymetrix U95Av2 array data are available at http://www.broad.mit.edu/cgi-bin/cancer/datasets.cgi. The cDNA microarray data are available through the Stanford Microarray Database (http://cmgm.stanford.edu/pbrown/. GeneLink software is freely available at http://bioinformatics.mdanderson.org/GeneLink/. DNA-Chip Analyzer software is publicly available at http://biosun1.harvard.edu/complab/dchip/.

  2. An efficient algorithm for the stochastic simulation of the hybridization of DNA to microarrays

    Directory of Open Access Journals (Sweden)

    Laurenzi Ian J

    2009-12-01

    Full Text Available Abstract Background Although oligonucleotide microarray technology is ubiquitous in genomic research, reproducibility and standardization of expression measurements still concern many researchers. Cross-hybridization between microarray probes and non-target ssDNA has been implicated as a primary factor in sensitivity and selectivity loss. Since hybridization is a chemical process, it may be modeled at a population-level using a combination of material balance equations and thermodynamics. However, the hybridization reaction network may be exceptionally large for commercial arrays, which often possess at least one reporter per transcript. Quantification of the kinetics and equilibrium of exceptionally large chemical systems of this type is numerically infeasible with customary approaches. Results In this paper, we present a robust and computationally efficient algorithm for the simulation of hybridization processes underlying microarray assays. Our method may be utilized to identify the extent to which nucleic acid targets (e.g. cDNA will cross-hybridize with probes, and by extension, characterize probe robustnessusing the information specified by MAGE-TAB. Using this algorithm, we characterize cross-hybridization in a modified commercial microarray assay. Conclusions By integrating stochastic simulation with thermodynamic prediction tools for DNA hybridization, one may robustly and rapidly characterize of the selectivity of a proposed microarray design at the probe and "system" levels. Our code is available at http://www.laurenzi.net.

  3. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  4. Transcriptional profiling of endocrine cerebro-osteodysplasia using microarray and next-generation sequencing.

    Directory of Open Access Journals (Sweden)

    Piya Lahiry

    Full Text Available BACKGROUND: Transcriptome profiling of patterns of RNA expression is a powerful approach to identify networks of genes that play a role in disease. To date, most mRNA profiling of tissues has been accomplished using microarrays, but next-generation sequencing can offer a richer and more comprehensive picture. METHODOLOGY/PRINCIPAL FINDINGS: ECO is a rare multi-system developmental disorder caused by a homozygous mutation in ICK encoding intestinal cell kinase. We performed gene expression profiling using both cDNA microarrays and next-generation mRNA sequencing (mRNA-seq of skin fibroblasts from ECO-affected subjects. We then validated a subset of differentially expressed transcripts identified by each method using quantitative reverse transcription-polymerase chain reaction (qRT-PCR. Finally, we used gene ontology (GO to identify critical pathways and processes that were abnormal according to each technical platform. Methodologically, mRNA-seq identifies a much larger number of differentially expressed genes with much better correlation to qRT-PCR results than the microarray (r² = 0.794 and 0.137, respectively. Biologically, cDNA microarray identified functional pathways focused on anatomical structure and development, while the mRNA-seq platform identified a higher proportion of genes involved in cell division and DNA replication pathways. CONCLUSIONS/SIGNIFICANCE: Transcriptome profiling with mRNA-seq had greater sensitivity, range and accuracy than the microarray. The two platforms generated different but complementary hypotheses for further evaluation.

  5. Microarray Developed on Plastic Substrates.

    Science.gov (United States)

    Bañuls, María-José; Morais, Sergi B; Tortajada-Genaro, Luis A; Maquieira, Ángel

    2016-01-01

    There is a huge potential interest to use synthetic polymers as versatile solid supports for analytical microarraying. Chemical modification of polycarbonate (PC) for covalent immobilization of probes, micro-printing of protein or nucleic acid probes, development of indirect immunoassay, and development of hybridization protocols are described and discussed.

  6. Identification of genes related to high royal jelly production in the honey bee (Apis mellifera) using microarray analysis

    OpenAIRE

    Nie, Hongyi; Liu, Xiaoyan; Pan, Jiao; Li, Wenfeng; Li, Zhiguo; Zhang, Shaowu; Chen, Shenglu; Miao, Xiaoqing; Zheng, Nenggan; Su, Songkun

    2017-01-01

    Abstract China is the largest royal jelly producer and exporter in the world, and high royal jelly-yielding strains have been bred in the country for approximately three decades. However, information on the molecular mechanism underlying high royal jelly production is scarce. Here, a cDNA microarray was used to screen and identify differentially expressed genes (DEGs) to obtain an overview on the changes in gene expression levels between high and low royal jelly producing bees. We developed a...

  7. cDNA sequences reveal considerable gene prediction inaccuracy in the Plasmodium falciparum genome

    Directory of Open Access Journals (Sweden)

    Valenzuela Jesus G

    2007-07-01

    Full Text Available Abstract Background The completion of the Plasmodium falciparum genome represents a milestone in malaria research. The genome sequence allows for the development of genome-wide approaches such as microarray and proteomics that will greatly facilitate our understanding of the parasite biology and accelerate new drug and vaccine development. Designing and application of these genome-wide assays, however, requires accurate information on gene prediction and genome annotation. Unfortunately, the genes in the parasite genome databases were mostly identified using computer software that could make some erroneous predictions. Results We aimed to obtain cDNA sequences to examine the accuracy of gene prediction in silico. We constructed cDNA libraries from mixed blood stages of P. falciparum parasite using the SMART cDNA library construction technique and generated 17332 high-quality expressed sequence tags (EST, including 2198 from primer-walking experiments. Assembly of our sequence tags produced 2548 contigs and 2671 singletons versus 5220 contigs and 5910 singletons when our EST were assembled with EST in public databases. Comparison of all the assembled EST/contigs with predicted CDS and genomic sequences in the PlasmoDB database identified 356 genes with predicted coding sequences fully covered by EST, including 85 genes (23.6% with introns incorrectly predicted. Careful automatic software and manual alignments found an additional 308 genes that have introns different from those predicted, with 152 new introns discovered and 182 introns with sizes or locations different from those predicted. Alternative spliced and antisense transcripts were also detected. Matching cDNA to predicted genes also revealed silent chromosomal regions, mostly at subtelomere regions. Conclusion Our data indicated that approximately 24% of the genes in the current databases were predicted incorrectly, although some of these inaccuracies could represent alternatively

  8. Diagnostic and analytical applications of protein microarrays

    DEFF Research Database (Denmark)

    Dufva, Hans Martin; Christensen, C.B.V.

    2005-01-01

    DNA microarrays have changed the field of biomedical sciences over the past 10 years. For several reasons, antibody and other protein microarrays have not developed at the same rate. However, protein and antibody arrays have emerged as a powerful tool to complement DNA microarrays during the post...

  9. A salmonid EST genomic study: genes, duplications, phylogeny and microarrays

    Directory of Open Access Journals (Sweden)

    Brahmbhatt Sonal

    2008-11-01

    Full Text Available Abstract Background Salmonids are of interest because of their relatively recent genome duplication, and their extensive use in wild fisheries and aquaculture. A comprehensive gene list and a comparison of genes in some of the different species provide valuable genomic information for one of the most widely studied groups of fish. Results 298,304 expressed sequence tags (ESTs from Atlantic salmon (69% of the total, 11,664 chinook, 10,813 sockeye, 10,051 brook trout, 10,975 grayling, 8,630 lake whitefish, and 3,624 northern pike ESTs were obtained in this study and have been deposited into the public databases. Contigs were built and putative full-length Atlantic salmon clones have been identified. A database containing ESTs, assemblies, consensus sequences, open reading frames, gene predictions and putative annotation is available. The overall similarity between Atlantic salmon ESTs and those of rainbow trout, chinook, sockeye, brook trout, grayling, lake whitefish, northern pike and rainbow smelt is 93.4, 94.2, 94.6, 94.4, 92.5, 91.7, 89.6, and 86.2% respectively. An analysis of 78 transcript sets show Salmo as a sister group to Oncorhynchus and Salvelinus within Salmoninae, and Thymallinae as a sister group to Salmoninae and Coregoninae within Salmonidae. Extensive gene duplication is consistent with a genome duplication in the common ancestor of salmonids. Using all of the available EST data, a new expanded salmonid cDNA microarray of 32,000 features was created. Cross-species hybridizations to this cDNA microarray indicate that this resource will be useful for studies of all 68 salmonid species. Conclusion An extensive collection and analysis of salmonid RNA putative transcripts indicate that Pacific salmon, Atlantic salmon and charr are 94–96% similar while the more distant whitefish, grayling, pike and smelt are 93, 92, 89 and 86% similar to salmon. The salmonid transcriptome reveals a complex history of gene duplication that is

  10. DNA microarray technique for detecting food-borne pathogens

    Directory of Open Access Journals (Sweden)

    Xing GAO

    2012-08-01

    Full Text Available Objective To study the application of DNA microarray technique for screening and identifying multiple food-borne pathogens. Methods The oligonucleotide probes were designed by Clustal X and Oligo 6.0 at the conserved regions of specific genes of multiple food-borne pathogens, and then were validated by bioinformatic analyses. The 5' end of each probe was modified by amino-group and 10 Poly-T, and the optimized probes were synthesized and spotted on aldehyde-coated slides. The bacteria DNA template incubated with Klenow enzyme was amplified by arbitrarily primed PCR, and PCR products incorporated into Aminoallyl-dUTP were coupled with fluorescent dye. After hybridization of the purified PCR products with DNA microarray, the hybridization image and fluorescence intensity analysis was acquired by ScanArray and GenePix Pro 5.1 software. A series of detection conditions such as arbitrarily primed PCR and microarray hybridization were optimized. The specificity of this approach was evaluated by 16 different bacteria DNA, and the sensitivity and reproducibility were verified by 4 food-borne pathogens DNA. The samples of multiple bacteria DNA and simulated water samples of Shigella dysenteriae were detected. Results Nine different food-borne bacteria were successfully discriminated under the same condition. The sensitivity of genomic DNA was 102 -103pg/ μl, and the coefficient of variation (CV of the reproducibility of assay was less than 15%. The corresponding specific hybridization maps of the multiple bacteria DNA samples were obtained, and the detection limit of simulated water sample of Shigella dysenteriae was 3.54×105cfu/ml. Conclusions The DNA microarray detection system based on arbitrarily primed PCR can be employed for effective detection of multiple food-borne pathogens, and this assay may offer a new method for high-throughput platform for detecting bacteria.

  11. Cotton-wool spots.

    Science.gov (United States)

    Brown, G C; Brown, M M; Hiller, T; Fischer, D; Benson, W E; Magargal, L E

    1985-01-01

    A series of 24 consecutive patients presenting with a fundus picture characterized by a predominance of cotton-wool spots, or a single cotton-wool spot, is reported. Excluded were patients with known diabetes mellitus. Etiologic conditions found included previously undiagnosed diabetes mellitus in five patients, systemic hypertension in five patients, cardiac valvular disease in two patients, radiation retinopathy in two patients, and severe carotid artery obstruction in two patients. Dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, leukemia, AIDS, Purtscher's retinopathy, metastatic carcinoma, intravenous drug abuse, partial central retinal artery obstruction, and giant cell arteritis were each found in one patient. In only one patient did a systemic workup fail to reveal an underlying cause. The presence of even one cotton-wool spot in an otherwise normal fundus necessitates an investigation to ascertain systemic etiologic factors.

  12. cDNA structure, genomic organization and expression patterns of ...

    African Journals Online (AJOL)

    Visfatin was a newly identified adipocytokine, which was involved in various physiologic and pathologic processes of organisms. The cDNA structure, genomic organization and expression patterns of silver Prussian carp visfatin were described in this report. The silver Prussian carp visfatin cDNA cloned from the liver was ...

  13. cDNA structure, genomic organization and expression patterns of ...

    African Journals Online (AJOL)

    use

    2011-11-23

    Nov 23, 2011 ... Visfatin was a newly identified adipocytokine, which was involved in various physiologic and pathologic processes of organisms. The cDNA structure, genomic organization and expression patterns of silver Prussian carp visfatin were described in this report. The silver Prussian carp visfatin. cDNA cloned ...

  14. Genomic resources for Myzus persicae: EST sequencing, SNP identification, and microarray design

    Directory of Open Access Journals (Sweden)

    Malloch Gaynor

    2007-11-01

    Full Text Available Abstract Background The green peach aphid, Myzus persicae (Sulzer, is a world-wide insect pest capable of infesting more than 40 plant families, including many crop species. However, despite the significant damage inflicted by M. persicae in agricultural systems through direct feeding damage and by its ability to transmit plant viruses, limited genomic information is available for this species. Results Sequencing of 16 M. persicae cDNA libraries generated 26,669 expressed sequence tags (ESTs. Aphids for library construction were raised on Arabidopsis thaliana, Nicotiana benthamiana, Brassica oleracea, B. napus, and Physalis floridana (with and without Potato leafroll virus infection. The M. persicae cDNA libraries include ones made from sexual and asexual whole aphids, guts, heads, and salivary glands. In silico comparison of cDNA libraries identified aphid genes with tissue-specific expression patterns, and gene expression that is induced by feeding on Nicotiana benthamiana. Furthermore, 2423 genes that are novel to science and potentially aphid-specific were identified. Comparison of cDNA data from three aphid lineages identified single nucleotide polymorphisms that can be used as genetic markers and, in some cases, may represent functional differences in the protein products. In particular, non-conservative amino acid substitutions in a highly expressed gut protease may be of adaptive significance for M. persicae feeding on different host plants. The Agilent eArray platform was used to design an M. persicae oligonucleotide microarray representing over 10,000 unique genes. Conclusion New genomic resources have been developed for M. persicae, an agriculturally important insect pest. These include previously unknown sequence data, a collection of expressed genes, molecular markers, and a DNA microarray that can be used to study aphid gene expression. These resources will help elucidate the adaptations that allow M. persicae to develop compatible

  15. Concordance between RNA-sequencing data and DNA microarray data in transcriptome analysis of proliferative and quiescent fibroblasts

    Science.gov (United States)

    Trost, Brett; Moir, Catherine A.; Gillespie, Zoe E.; Kusalik, Anthony; Mitchell, Jennifer A.; Eskiw, Christopher H.

    2015-01-01

    DNA microarrays and RNA sequencing (RNA-seq) are major technologies for performing high-throughput analysis of transcript abundance. Recently, concerns have been raised regarding the concordance of data derived from the two techniques. Using cDNA libraries derived from normal human foreskin fibroblasts, we measured changes in transcript abundance as cells transitioned from proliferative growth to quiescence using both DNA microarrays and RNA-seq. The internal reproducibility of the RNA-seq data was greater than that of the microarray data. Correlations between the RNA-seq data and the individual microarrays were low, but correlations between the RNA-seq values and the geometric mean of the microarray values were moderate. The two technologies had good agreement when considering probes with the largest (both positive and negative) fold change (FC) values. An independent technique, quantitative reverse-transcription PCR (qRT-PCR), was used to measure the FC of 76 genes between proliferative and quiescent samples, and a higher correlation was observed between the qRT-PCR data and the RNA-seq data than between the qRT-PCR data and the microarray data. PMID:26473061

  16. Quality assessment of microarrays: Visualization of spatial artifacts and quantitation of regional biases

    Directory of Open Access Journals (Sweden)

    Weinstein John N

    2005-07-01

    Full Text Available Abstract Background Quality-control is an important issue in the analysis of gene expression microarrays. One type of problem is regional bias, in which one region of a chip shows artifactually high or low intensities (or ratios in a two-channel array relative to the majority of the chip. Current practice in quality assessment for microarrays does not address regional biases. Results We present methods implemented in R for visualizing regional biases and other spatial artifacts on spotted microarrays and Affymetrix chips. We also propose a statistical index to quantify regional bias and investigate its typical distribution on spotted and Affymetrix arrays. We demonstrate that notable regional biases occur on both Affymetrix and spotted arrays and that they can make a significant difference in the case of spotted microarray results. Although strong biases are also seen at the level of individual probes on Affymetrix chips, the gene expression measures are less affected, especially when the RMA method is used to summarize intensities for the probe sets. A web application program for visualization and quantitation of regional bias is provided at http://www.discover.nci.nih.gov/affytools. Conclusion Researchers should visualize and measure the regional biases and should estimate their impact on gene expression measurements obtained. Here, we (i introduce pictorial visualizations of the spatial biases; (ii present for Affymetrix chips a useful resolution of the biases into two components, one related to background, the other to intensity scale factor; (iii introduce a single parameter to reflect the global bias present across an array. We also examine the pattern distribution of such biases and conclude that algorithms based on smoothing are unlikely to compensate adequately for them.

  17. Molecular cloning of lupin leghemoglobin cDNA

    DEFF Research Database (Denmark)

    Konieczny, A; Jensen, E O; Marcker, K A

    1987-01-01

    Poly(A)+ RNA isolated from root nodules of yellow lupin (Lupinus luteus, var. Ventus) has been used as a template for the construction of a cDNA library. The ds cDNA was synthesized and inserted into the Hind III site of plasmid pBR 322 using synthetic Hind III linkers. Clones containing sequences...... specific for nodules were selected by differential colony hybridization using 32P-labeled cDNA synthesized either from nodule poly(A)+ RNA or from poly(A)+ RNA of uninfected root as probes. Among the recombinant plasmids, the cDNA gene for leghemoglobin was identified. The protein structure derived from...... its nucleotide sequence was consistent with known amino acid sequence of lupin Lb II. The cloned lupin Lb cDNA hybridized to poly(A)+ RNA from nodules only, which is in accordance with the general concept, that leghemoglobin is expressed exclusively in nodules. Udgivelsesdato: 1987-null...

  18. Sediment denitrifier community composition and nirS gene expression investigated with functional gene microarrays

    DEFF Research Database (Denmark)

    Francis, C.A.; Jackson, G.A.; Ward, B.B.

    2008-01-01

    A functional gene microarray was used to investigate denitrifier community composition and nitrite reductase (nirS) gene expression in sediments along the estuarine gradient in Chesapeake Bay, USA. The nirS oligonucleotide probe set was designed to represent a sequence database containing 539...... Chesapeake Bay clones, as well as sequences from many other environments. Greatest nirS diversity was detected at the freshwater station at the head of the bay and least diversity at the higher salinity station near the mouth of the Bay. The most common OTUs from the sequence database were detected...... on the array with high signal strength in most samples. One of the most abundant OTUs, CB2-S-138, was identified as dominant at the mid-bay site by both microarray and quantitative PCR assays, but it comprised a much smaller fraction of the assemblage in the north and south bay samples. cDNA (transcribed from...

  19. [Construction of chicken embryo fibroblasts cDNA expression library].

    Science.gov (United States)

    Liu, Wei; Gao, Yu-long; Gao, Hong-lei; Wang, Xiao-mei; Xu, Xiu-hong

    2007-06-01

    Chicken embryo fibroblast (CEF) is a primary cellular material to research the infectious bursal disease virus (IBDV). Constructing the cDNA expression library of CEF is the foundation to research cell tropism and find cell receptors of IBDV from CEF. In order to achieve that purpose, a high-quality cDNA expression library of CEF was constructed by Gateway technology, which could avoid using the restriction enzyme for cloning to solve technical limitation of roution method. The mRNA was extracted from chicken embryonic fibroblast. Moreover, single-strand cDNA and double-strand cDNA were synthesized by using biotin-conjugated Oligo (dT) primer in turn. The double-strand cDNA was ligated Adapter and then purified by the cDNA Size Fractionation Columns. After BP recombination reaction, a cDNA entry library was constructed with a titer of 1 x 10(6) cfu/mL, total clones of 1.2 x 10(7) cfu and an average insertion size of about 2243 bp. After LR recombination reaction, the cDNA entry library was transformed into expression library which took on a titer of 5 x 10(5) cfu/mL, total clones of 5.5 x 10(6) cfu and an average insertion size of about 2411bp. The results indicate that the constructed cDNA expression library performs a remarkable high value in both recombination rate and library coverage. As a result, the cDNA expression library, with its good quality, may facilitate to identify the receptors associated with the resistance against IBDV in chicken embryonic fibroblast and to cast new light on the mechanism of cellular tropism. Moreover, it may also provide data of chicken embryonic fibroblast in transcription level and may be helpful to study its biological functions.

  20. Spot14/Spot14R expression may be involved in MSC adipogenic differentiation in patients with adolescent idiopathic scoliosis

    Science.gov (United States)

    WANG, QIFEI; YANG, JUNLIN; LIN, XIANG; HUANG, ZIFANG; XIE, CHAOFAN; FAN, HENGWEI

    2016-01-01

    The aim of the present study was to evaluate the different expression levels of thyroid hormone responsive (THRSP; Spot14)/S14 related, Mig12 (S14R) during bone marrow mesenchymal stem cell (BM-MSC) adipogenesis in adolescent idiopathic scoliosis (AIS) patients. MSCs were retrospectively isolated from AIS patients and controls, and adipogenic differentiation was induced. Total RNA was extracted for Affymetrix 3′-IVT expression profiling microarrays and compared with the results from healthy controls. The results were confirmed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) validation and the protein expression levels of Spot14 and its paralogous gene S14R by western blotting and immunohistochemistry. A total of 300 significantly altered mRNAs were detected (111 upregulated and 189 downregulated) and confirmed by RT-qPCR. The mRNA expression levels of seven genes, including Spot14, were altered by >2-fold in AIS patients. Spot14/S14R was selected for further investigation. The results of the western blotting demonstrated that mRNA and protein expression levels of Spot14/S14R were significantly higher in AIS patients than the controls (P<0.05). Immunohistochemistry demonstrated Spot14 was expressed in 85% (17/20 cases) in adipose tissue samples from AIS patients and 23.1% (3/13 cases) of adipose tissue samples from controls. The positive ratio of Spot14 in adipose tissue samples from AIS was significantly higher than the controls (P<0.001). The results of the present study indicated that Spot14/S14R were differently expressed in MSC adipogenesis in AIS patients, and they may be important in the abnormal adipogenic differentiation in AIS. PMID:27082501

  1. [The construction of rapid amplification of cDNA ends cDNA libraries from human fetal bone and joint].

    Science.gov (United States)

    Liang, X; Gong, Y; Liu, Q; Li, J; Chen, B; Guo, C

    2001-02-01

    To construct rapid amplification cDNA ends(RACE) cDNA libraries from human fetal bone and joint and provide resources for isolation of bone- and joint-specific development-related genes. Total RNA of bone and joint were extracted with the modified single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. The double-stranded end-blunted cDNA were synthesized using TaKaRa's cDNA synthesis kit and ligated to cassette adaptors. All of the cDNA molecules were amplified by a pair of common primers. A protocol for RACE cDNA library construction from bone and joint was established and two RACE cDNA libraries from human fetal bone and joint were successfully constructed. The protocol of RACE cDNA library construction from limited materials proved to be simple and efficient and the library was suitable for RACE to isolate tissue-specific genes.

  2. Transcriptome sequencing of the Microarray Quality Control (MAQC RNA reference samples using next generation sequencing

    Directory of Open Access Journals (Sweden)

    Thierry-Mieg Danielle

    2009-06-01

    Full Text Available Abstract Background Transcriptome sequencing using next-generation sequencing platforms will soon be competing with DNA microarray technologies for global gene expression analysis. As a preliminary evaluation of these promising technologies, we performed deep sequencing of cDNA synthesized from the Microarray Quality Control (MAQC reference RNA samples using Roche's 454 Genome Sequencer FLX. Results We generated more that 3.6 million sequence reads of average length 250 bp for the MAQC A and B samples and introduced a data analysis pipeline for translating cDNA read counts into gene expression levels. Using BLAST, 90% of the reads mapped to the human genome and 64% of the reads mapped to the RefSeq database of well annotated genes with e-values ≤ 10-20. We measured gene expression levels in the A and B samples by counting the numbers of reads that mapped to individual RefSeq genes in multiple sequencing runs to evaluate the MAQC quality metrics for reproducibility, sensitivity, specificity, and accuracy and compared the results with DNA microarrays and Quantitative RT-PCR (QRTPCR from the MAQC studies. In addition, 88% of the reads were successfully aligned directly to the human genome using the AceView alignment programs with an average 90% sequence similarity to identify 137,899 unique exon junctions, including 22,193 new exon junctions not yet contained in the RefSeq database. Conclusion Using the MAQC metrics for evaluating the performance of gene expression platforms, the ExpressSeq results for gene expression levels showed excellent reproducibility, sensitivity, and specificity that improved systematically with increasing shotgun sequencing depth, and quantitative accuracy that was comparable to DNA microarrays and QRTPCR. In addition, a careful mapping of the reads to the genome using the AceView alignment programs shed new light on the complexity of the human transcriptome including the discovery of thousands of new splice variants.

  3. Fish ‘n’ chips: the use of microarrays for aquatic toxicology

    Science.gov (United States)

    Denslow, Nancy D.; Garcia-Reyero, Natàlia; Barber, David S.

    2007-01-01

    Gene expression analysis is changing the way that we look at toxicity, allowing toxicologists to perform parallel analyses of entire transcriptomes. While this technology is not as advanced in aquatic toxicology as it is for mammalian models, it has shown promise for determining modes of action, identifying biomarkers and developing ‘‘signatures’’ of chemicals that can be used for field and mixture studies. A major hurdle for the use of microarrays in aquatic toxicology is the lack of sequence information for non-model species. Custom arrays based on gene libraries enriched for genes that are expressed in response to specific contaminants have been used with excellent success for some non-model species, suggesting that this approach will work well for ecotoxicology and spurring on the sequencing of cDNA libraries for species of interest. New sequencing technology and development of repositories for gene expression data will accelerate the use of microarrays in aquatic toxicology. Notwithstanding the preliminary successes that have been achieved even with partial cDNA libraries printed on arrays, ecological samples present elevated challenges for this technology due to the high degree of variation of the samples. Furthermore, recent studies that show nonlinear toxic responses for ecological species underscore the necessity of establishing time and dose dependence of effects on gene expression and comparing these results with traditional markers of toxicity. To realize the full potential of microarrays, researchers must do the experiments required to bridge the gap between the ‘omics’ technologies and traditional toxicology to demonstrate that microarrays have predictive value in ecotoxicology. PMID:17308663

  4. In silico design and performance of peptide microarrays for breast cancer tumour-auto-antibody testing

    Directory of Open Access Journals (Sweden)

    Andreas Weinhäusel

    2012-06-01

    Full Text Available The simplicity and potential of minimally invasive testing using sera from patients makes auto-antibody based biomarkers a very promising tool for use in cancer diagnostics. Protein microarrays have been used for the identification of such auto-antibody signatures. Because high throughput protein expression and purification is laborious, synthetic peptides might be a good alternative for microarray generation and multiplexed analyses. In this study, we designed 1185 antigenic peptides, deduced from proteins expressed by 642 cDNA expression clones found to be sero-reactive in both breast tumour patients and controls. The sero-reactive proteins and the corresponding peptides were used for the production of protein and peptide microarrays. Serum samples from females with benign and malignant breast tumours and healthy control sera (n=16 per group were then analysed. Correct classification of the serum samples on peptide microarrays were 78% for discrimination of ‘malignant versus healthy controls’, 72% for ‘benign versus malignant’ and 94% for ‘benign versus controls’. On protein arrays, correct classification for these contrasts was 69%, 59% and 59%, respectively. The over-representation analysis of the classifiers derived from class prediction showed enrichment of genes associated with ribosomes, spliceosomes, endocytosis and the pentose phosphate pathway. Sequence analyses of the peptides with the highest sero-reactivity demonstrated enrichment of the zinc-finger domain. Peptides’ sero-reactivities were found negatively correlated with hydrophobicity and positively correlated with positive charge, high inter-residue protein contact energies and a secondary structure propensity bias. This study hints at the possibility of using in silico designed antigenic peptide microarrays as an alternative to protein microarrays for the improvement of tumour auto-antibody based diagnostics.

  5. Overview of Microarray Analysis of Gene Expression and its Applications to Cervical Cancer Investigation

    Directory of Open Access Journals (Sweden)

    Angel Chao

    2007-12-01

    Full Text Available Cervical cancer is one of the leading female cancers in Taiwan and ranks as the fifth cause of cancer death in the female population. Human papillomavirus has been established as the causative agent for cervical neoplasia and cervical cancer. However, the tumor biology involved in the prognoses of different cell types in early cancers and tumor responses to radiation in advanced cancers remain largely unknown. The introduction of microarray technologies in the 1990s has provided genome-wide strategies for searching tens of thousands of genes simultaneously. In this review, we first summarize the two types of microarrays: oligonucleotides microarray and cDNA microarray. Then, we review the studies of functional genomics in cervical cancer. Gene expression studies that involved cervical cancer cell lines, cervical cells of cancer versus normal ectocervix, cancer tissues of different histology, radioresistant versus radiosensitive patients, and the combinatorial gene expression associated with chromosomal amplifications are discussed. In particular, CEACAM5, TACSTD1, S100P, and MSLN have shown to be upregulated in adenocarcinoma, and increased expression levels of CEACAM5 and TACSTD1 were significantly correlated with poorer patient outcomes. On the other hand, 35 genes, including apoptotic genes (e.g. BIK, TEGT, SSI-3, hypoxia-inducible genes (e.g. HIF1A, CA12, and tumor cell invasion and metastasis genes (e.g. CTSL, CTSB, PLAU, CD44, have been noted to echo the hypothesis that increased tumor hypoxia leads to radiation resistance in cervical cancer during radiation.

  6. Drop drying on surfaces determines chemical reactivity - the specific case of immobilization of oligonucleotides on microarrays

    Science.gov (United States)

    2013-01-01

    Background Drop drying is a key factor in a wide range of technical applications, including spotted microarrays. The applied nL liquid volume provides specific reaction conditions for the immobilization of probe molecules to a chemically modified surface. Results We investigated the influence of nL and μL liquid drop volumes on the process of probe immobilization and compare the results obtained to the situation in liquid solution. In our data, we observe a strong relationship between drop drying effects on immobilization and surface chemistry. In this work, we present results on the immobilization of dye labeled 20mer oligonucleotides with and without an activating 5′-aminoheptyl linker onto a 2D epoxysilane and a 3D NHS activated hydrogel surface. Conclusions Our experiments identified two basic processes determining immobilization. First, the rate of drop drying that depends on the drop volume and the ambient relative humidity. Oligonucleotides in a dried spot react unspecifically with the surface and long reaction times are needed. 3D hydrogel surfaces allow for immobilization in a liquid environment under diffusive conditions. Here, oligonucleotide immobilization is much faster and a specific reaction with the reactive linker group is observed. Second, the effect of increasing probe concentration as a result of drop drying. On a 3D hydrogel, the increasing concentration of probe molecules in nL spotting volumes accelerates immobilization dramatically. In case of μL volumes, immobilization depends on whether the drop is allowed to dry completely. At non-drying conditions, very limited immobilization is observed due to the low oligonucleotide concentration used in microarray spotting solutions. The results of our study provide a general guideline for microarray assay development. They allow for the initial definition and further optimization of reaction conditions for the immobilization of oligonucleotides and other probe molecule classes to different

  7. Cloning of the human androgen receptor cDNA

    International Nuclear Information System (INIS)

    Govindan, M.V.; Burelle, M.; Cantin, C.; Kabrie, C.; Labrie, F.; Lachance, Y.; Leblanc, G.; Lefebvre, C.; Patel, P.; Simard, J.

    1988-01-01

    The authors discuss how in order to define the functional domains of the human androgen receptor, complementary DNA (cDNA) clones encoding the human androgen receptor (hAR) have been isolated from a human testis λgtll cDNA library using synthetic oligonnucleotide probes, homologous to segments of the human glucocorticoid, estradiol and progesterone receptors. The cDNA clones corresponding to the human glucocorticoid, estradiol and progesterone receptors were eliminated after cross-hybridization with their respective cDNA probes and/or after restriction mapping of the cDNA clones. The remaining cDNA clones were classified into different groups after analysis by restriction digestion and cross-hybridization. Two of the largest cDNA clones from each group were inserted into an expression vector in both orientations. The linearized plasmids were used as templates in in vitro transcription with T7 RNA polymerase. Subsequent in vitro translation of the purified transcripts in rabbit reticulocyte lysate followed by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) permitted the characterization of the encoded polyeptides. The expressed proteins larger than 30,000 Da were analyzed for their ability to bind tritium-labelled dihydrotestosterone ([ 3 H] DHT) with high affinity and specificity

  8. The EADGENE Microarray Data Analysis Workshop

    DEFF Research Database (Denmark)

    de Koning, Dirk-Jan; Jaffrézic, Florence; Lund, Mogens Sandø

    2007-01-01

    Microarray analyses have become an important tool in animal genomics. While their use is becoming widespread, there is still a lot of ongoing research regarding the analysis of microarray data. In the context of a European Network of Excellence, 31 researchers representing 14 research groups from...... 10 countries performed and discussed the statistical analyses of real and simulated 2-colour microarray data that were distributed among participants. The real data consisted of 48 microarrays from a disease challenge experiment in dairy cattle, while the simulated data consisted of 10 microarrays...... from a direct comparison of two treatments (dye-balanced). While there was broader agreement with regards to methods of microarray normalisation and significance testing, there were major differences with regards to quality control. The quality control approaches varied from none, through using...

  9. Development and evaluation of a high-throughput, low-cost genotyping platform based on oligonucleotide microarrays in rice

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2008-05-01

    Full Text Available Abstract Background We report the development of a microarray platform for rapid and cost-effective genetic mapping, and its evaluation using rice as a model. In contrast to methods employing whole-genome tiling microarrays for genotyping, our method is based on low-cost spotted microarray production, focusing only on known polymorphic features. Results We have produced a genotyping microarray for rice, comprising 880 single feature polymorphism (SFP elements derived from insertions/deletions identified by aligning genomic sequences of the japonica cultivar Nipponbare and the indica cultivar 93-11. The SFPs were experimentally verified by hybridization with labeled genomic DNA prepared from the two cultivars. Using the genotyping microarrays, we found high levels of polymorphism across diverse rice accessions, and were able to classify all five subpopulations of rice with high bootstrap support. The microarrays were used for mapping of a gene conferring resistance to Magnaporthe grisea, the causative organism of rice blast disease, by quantitative genotyping of samples from a recombinant inbred line population pooled by phenotype. Conclusion We anticipate this microarray-based genotyping platform, based on its low cost-per-sample, to be particularly useful in applications requiring whole-genome molecular marker coverage across large numbers of individuals.

  10. The EADGENE Microarray Data Analysis Workshop

    OpenAIRE

    de Koning, Dirk-Jan; Jaffrézic, Florence; Lund, Mogens Sandø; Watson, Michael; Channing, Caroline; Hulsegge, Ina; Pool, Marco; Buitenhuis, Bart; Hedegaard, Jakob; Hornshøj, Henrik; Jiang, Li; Sørensen, Peter; Marot, Guillemette; Delmas, Céline; Lê Cao, Kim-Anh

    2007-01-01

    Abstract Microarray analyses have become an important tool in animal genomics. While their use is becoming widespread, there is still a lot of ongoing research regarding the analysis of microarray data. In the context of a European Network of Excellence, 31 researchers representing 14 research groups from 10 countries performed and discussed the statistical analyses of real and simulated 2-colour microarray data that were distributed among participants. The real data consisted of 48 microarra...

  11. Molecular cloning of lupin leghemoglobin cDNA

    DEFF Research Database (Denmark)

    Konieczny, A; Jensen, E O; Marcker, K A

    1987-01-01

    Poly(A)+ RNA isolated from root nodules of yellow lupin (Lupinus luteus, var. Ventus) has been used as a template for the construction of a cDNA library. The ds cDNA was synthesized and inserted into the Hind III site of plasmid pBR 322 using synthetic Hind III linkers. Clones containing sequences...... its nucleotide sequence was consistent with known amino acid sequence of lupin Lb II. The cloned lupin Lb cDNA hybridized to poly(A)+ RNA from nodules only, which is in accordance with the general concept, that leghemoglobin is expressed exclusively in nodules. Udgivelsesdato: 1987-null...

  12. Fabrication of protein microarrays for alpha fetoprotein detection by using a rapid photo-immobilization process

    Directory of Open Access Journals (Sweden)

    Sirasa Yodmongkol

    2016-03-01

    Full Text Available In this study, protein microarrays based on sandwich immunoassays are generated to quantify the amount of alpha fetoprotein (AFP in blood serum. For chip generation a mixture of capture antibody and a photoactive copolymer consisting of N,N-dimethylacrylamide (DMAA, methacryloyloxy benzophenone (MaBP, and Na-4-styrenesulfonate (SSNa was spotted onto unmodified polymethyl methacrylate (PMMA substrates. Subsequently to printing of the microarray, the polymer and protein were photochemically cross-linked and the forming, biofunctionalized hydrogels simultaneously bound to the chip surface by short UV- irradiation. The obtained biochip was incubated with AFP antigen, followed by biotinylated AFP antibody and streptavidin-Cy5 and the fluorescence signal read-out. The developed microarray biochip covers the range of AFP in serum samples such as maternal serum in the range of 5 and 100 ng/ml. The chip production process is based on a fast and simple immobilization process, which can be applied to conventional plastic surfaces. Therefore, this protein microarray production process is a promising method to fabricate biochips for AFP screening processes. Keywords: Photo-immobilization, Protein microarray, Alpha fetoprotein, Hydrogel, 3D surface, Down syndrome

  13. Gene expression profiling of whole blood: Comparison of target preparation methods for accurate and reproducible microarray analysis

    Science.gov (United States)

    Vartanian, Kristina; Slottke, Rachel; Johnstone, Timothy; Casale, Amanda; Planck, Stephen R; Choi, Dongseok; Smith, Justine R; Rosenbaum, James T; Harrington, Christina A

    2009-01-01

    Background Peripheral blood is an accessible and informative source of transcriptomal information for many human disease and pharmacogenomic studies. While there can be significant advantages to analyzing RNA isolated from whole blood, particularly in clinical studies, the preparation of samples for microarray analysis is complicated by the need to minimize artifacts associated with highly abundant globin RNA transcripts. The impact of globin RNA transcripts on expression profiling data can potentially be reduced by using RNA preparation and labeling methods that remove or block globin RNA during the microarray assay. We compared four different methods for preparing microarray hybridization targets from human whole blood collected in PAXGene tubes. Three of the methods utilized the Affymetrix one-cycle cDNA synthesis/in vitro transcription protocol but varied treatment of input RNA as follows: i. no treatment; ii. treatment with GLOBINclear; or iii. treatment with globin PNA oligos. In the fourth method cDNA targets were prepared with the Ovation amplification and labeling system. Results We find that microarray targets generated with labeling methods that reduce globin mRNA levels or minimize the impact of globin transcripts during hybridization detect more transcripts in the microarray assay compared with the standard Affymetrix method. Comparison of microarray results with quantitative PCR analysis of a panel of genes from the NF-kappa B pathway shows good correlation of transcript measurements produced with all four target preparation methods, although method-specific differences in overall correlation were observed. The impact of freezing blood collected in PAXGene tubes on data reproducibility was also examined. Expression profiles show little or no difference when RNA is extracted from either fresh or frozen blood samples. Conclusion RNA preparation and labeling methods designed to reduce the impact of globin mRNA transcripts can significantly improve the

  14. SSHscreen and SSHdb, generic software for microarray based gene discovery: application to the stress response in cowpea

    Directory of Open Access Journals (Sweden)

    Oelofse Dean

    2010-04-01

    Full Text Available Abstract Background Suppression subtractive hybridization is a popular technique for gene discovery from non-model organisms without an annotated genome sequence, such as cowpea (Vigna unguiculata (L. Walp. We aimed to use this method to enrich for genes expressed during drought stress in a drought tolerant cowpea line. However, current methods were inefficient in screening libraries and management of the sequence data, and thus there was a need to develop software tools to facilitate the process. Results Forward and reverse cDNA libraries enriched for cowpea drought response genes were screened on microarrays, and the R software package SSHscreen 2.0.1 was developed (i to normalize the data effectively using spike-in control spot normalization, and (ii to select clones for sequencing based on the calculation of enrichment ratios with associated statistics. Enrichment ratio 3 values for each clone showed that 62% of the forward library and 34% of the reverse library clones were significantly differentially expressed by drought stress (adjusted p value 88% of the clones in both libraries were derived from rare transcripts in the original tester samples, thus supporting the notion that suppression subtractive hybridization enriches for rare transcripts. A set of 118 clones were chosen for sequencing, and drought-induced cowpea genes were identified, the most interesting encoding a late embryogenesis abundant Lea5 protein, a glutathione S-transferase, a thaumatin, a universal stress protein, and a wound induced protein. A lipid transfer protein and several components of photosynthesis were down-regulated by the drought stress. Reverse transcriptase quantitative PCR confirmed the enrichment ratio values for the selected cowpea genes. SSHdb, a web-accessible database, was developed to manage the clone sequences and combine the SSHscreen data with sequence annotations derived from BLAST and Blast2GO. The self-BLAST function within SSHdb grouped

  15. SSHscreen and SSHdb, generic software for microarray based gene discovery: application to the stress response in cowpea

    Science.gov (United States)

    2010-01-01

    Background Suppression subtractive hybridization is a popular technique for gene discovery from non-model organisms without an annotated genome sequence, such as cowpea (Vigna unguiculata (L.) Walp). We aimed to use this method to enrich for genes expressed during drought stress in a drought tolerant cowpea line. However, current methods were inefficient in screening libraries and management of the sequence data, and thus there was a need to develop software tools to facilitate the process. Results Forward and reverse cDNA libraries enriched for cowpea drought response genes were screened on microarrays, and the R software package SSHscreen 2.0.1 was developed (i) to normalize the data effectively using spike-in control spot normalization, and (ii) to select clones for sequencing based on the calculation of enrichment ratios with associated statistics. Enrichment ratio 3 values for each clone showed that 62% of the forward library and 34% of the reverse library clones were significantly differentially expressed by drought stress (adjusted p value 88% of the clones in both libraries were derived from rare transcripts in the original tester samples, thus supporting the notion that suppression subtractive hybridization enriches for rare transcripts. A set of 118 clones were chosen for sequencing, and drought-induced cowpea genes were identified, the most interesting encoding a late embryogenesis abundant Lea5 protein, a glutathione S-transferase, a thaumatin, a universal stress protein, and a wound induced protein. A lipid transfer protein and several components of photosynthesis were down-regulated by the drought stress. Reverse transcriptase quantitative PCR confirmed the enrichment ratio values for the selected cowpea genes. SSHdb, a web-accessible database, was developed to manage the clone sequences and combine the SSHscreen data with sequence annotations derived from BLAST and Blast2GO. The self-BLAST function within SSHdb grouped redundant clones together and

  16. Chocolate spot of Eucalyptus

    OpenAIRE

    Cheewangkoon, R.; Groenewald, J.Z.; Hyde, K.D.; To-anun, C.; Crous, P.W.

    2012-01-01

    Chocolate Spot leaf disease of Eucalyptus is associated with several Heteroconium-like species of hyphomycetes that resemble Heteroconium s.str. in morphology. They differ, however, in their ecology, with the former being plant pathogenic, while Heteroconium s.str. is a genus of sooty moulds. Results of molecular analyses, inferred from DNA sequences of the large subunit (LSU) and internal transcribed spacers (ITS) region of nrDNA, delineated four Heteroconium-like species on Eucalyptus, name...

  17. "Harshlighting" small blemishes on microarrays

    Directory of Open Access Journals (Sweden)

    Wittkowski Knut M

    2005-03-01

    Full Text Available Abstract Background Microscopists are familiar with many blemishes that fluorescence images can have due to dust and debris, glass flaws, uneven distribution of fluids or surface coatings, etc. Microarray scans show similar artefacts, which affect the analysis, particularly when one tries to detect subtle changes. However, most blemishes are hard to find by the unaided eye, particularly in high-density oligonucleotide arrays (HDONAs. Results We present a method that harnesses the statistical power provided by having several HDONAs available, which are obtained under similar conditions except for the experimental factor. This method "harshlights" blemishes and renders them evident. We find empirically that about 25% of our chips are blemished, and we analyze the impact of masking them on screening for differentially expressed genes. Conclusion Experiments attempting to assess subtle expression changes should be carefully screened for blemishes on the chips. The proposed method provides investigators with a novel robust approach to improve the sensitivity of microarray analyses. By utilizing topological information to identify and mask blemishes prior to model based analyses, the method prevents artefacts from confounding the process of background correction, normalization, and summarization.

  18. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  19. Molecular cloning and characterization of a cDNA encoding ...

    African Journals Online (AJOL)

    enoh

    2012-03-29

    Nanjing) co., Ltd. The nucleotide sequences of these primers are as follows: ..... Ebizuka Y (2000). Molecular cloning and characterization of a cDNA for Glycyrrhiza glabra cycloartenol synthase. Biol. Pharm. Bull. 23(2):231-234.

  20. Method for construction of normalized cDNA libraries

    Science.gov (United States)

    Soares, Marcelo B.; Efstratiadis, Argiris

    1998-01-01

    This invention provides a method to normalize a directional cDNA library constructed in a vector that allows propagation in single-stranded circle form comprising: (a) propagating the directional cDNA library in single-stranded circles; (b) generating fragments complementary to the 3' noncoding sequence of the single-stranded circles in the library to produce partial duplexes; (c) purifying the partial duplexes; (d) melting and reassociating the purified partial duplexes to appropriate Cot; and (e) purifying the unassociated single-stranded circles, thereby generating a normalized cDNA library. This invention also provides normalized cDNA libraries generated by the above-described method and uses of the generated libraries.

  1. Biocompatible Hydrogels for Microarray Cell Printing and Encapsulation

    Directory of Open Access Journals (Sweden)

    Akshata Datar

    2015-10-01

    Full Text Available Conventional drug screening processes are a time-consuming and expensive endeavor, but highly rewarding when they are successful. To identify promising lead compounds, millions of compounds are traditionally screened against therapeutic targets on human cells grown on the surface of 96-wells. These two-dimensional (2D cell monolayers are physiologically irrelevant, thus, often providing false-positive or false-negative results, when compared to cells grown in three-dimensional (3D structures such as hydrogel droplets. However, 3D cell culture systems are not easily amenable to high-throughput screening (HTS, thus inherently low throughput, and requiring relatively large volume for cell-based assays. In addition, it is difficult to control cellular microenvironments and hard to obtain reliable cell images due to focus position and transparency issues. To overcome these problems, miniaturized 3D cell cultures in hydrogels were developed via cell printing techniques where cell spots in hydrogels can be arrayed on the surface of glass slides or plastic chips by microarray spotters and cultured in growth media to form cells encapsulated 3D droplets for various cell-based assays. These approaches can dramatically reduce assay volume, provide accurate control over cellular microenvironments, and allow us to obtain clear 3D cell images for high-content imaging (HCI. In this review, several hydrogels that are compatible to microarray printing robots are discussed for miniaturized 3D cell cultures.

  2. Biocompatible Hydrogels for Microarray Cell Printing and Encapsulation.

    Science.gov (United States)

    Datar, Akshata; Joshi, Pranav; Lee, Moo-Yeal

    2015-10-26

    Conventional drug screening processes are a time-consuming and expensive endeavor, but highly rewarding when they are successful. To identify promising lead compounds, millions of compounds are traditionally screened against therapeutic targets on human cells grown on the surface of 96-wells. These two-dimensional (2D) cell monolayers are physiologically irrelevant, thus, often providing false-positive or false-negative results, when compared to cells grown in three-dimensional (3D) structures such as hydrogel droplets. However, 3D cell culture systems are not easily amenable to high-throughput screening (HTS), thus inherently low throughput, and requiring relatively large volume for cell-based assays. In addition, it is difficult to control cellular microenvironments and hard to obtain reliable cell images due to focus position and transparency issues. To overcome these problems, miniaturized 3D cell cultures in hydrogels were developed via cell printing techniques where cell spots in hydrogels can be arrayed on the surface of glass slides or plastic chips by microarray spotters and cultured in growth media to form cells encapsulated 3D droplets for various cell-based assays. These approaches can dramatically reduce assay volume, provide accurate control over cellular microenvironments, and allow us to obtain clear 3D cell images for high-content imaging (HCI). In this review, several hydrogels that are compatible to microarray printing robots are discussed for miniaturized 3D cell cultures.

  3. A new approach to species determination for yeast strains: DNA microarray-based comparative genomic hybridization using a yeast DNA microarray with 6000 genes.

    Science.gov (United States)

    Watanabe, Takahito; Murata, Yoshinori; Oka, Syuichi; Iwahashi, Hitoshi

    2004-03-01

    DNA-DNA hybridization is known as the superior method in the elucidation of relationships between closely related taxa, such as species and strain. For species determination we propose a new DNA-DNA hybridization method: the DNA microarray-based comparative genomic hybridization (CGH) method, using a yeast DNA microarray with approximately 6000 genes. The genome from a yeast strain as a sample strain (Sample) was labelled with Cy3-dye and hybridized to a single DNA microarray, together with the Cy5-labelled genome of S. cerevisiae S288C as a reference strain (Reference). The log2 ratio values [log2[Cy3(Sample)/Cy5(Reference)]: Ratio] of signal intensities of all the gene spots were estimated and divided into the following groups: Ratio < or = -1; -1 < Ratio < 1; 1 < or = Ratio. The hybridization profiles of the genomes of type strains belonging to the genus Saccharomyces were significantly different from that of S. cerevisiae S288C. The Ratio-based grouping allowed us to discriminate between some species from S. cerevisiae more clearly. Furthermore, cluster analysis discriminated between closely related species and strains. Using this method, we were able to not only perform species determination but also to obtain information on alternation in gene copy number of such gene amplifications and deletions with single-gene resolution. These observations indicated that DNA microarray-based CGH is a powerful system for species determination and comparative genome analysis. Copyright 2004 John Wiley & Sons, Ltd.

  4. Constructing and detecting a cDNA library for mites.

    Science.gov (United States)

    Hu, Li; Zhao, YaE; Cheng, Juan; Yang, YuanJun; Li, Chen; Lu, ZhaoHui

    2015-10-01

    RNA extraction and construction of complementary DNA (cDNA) library for mites have been quite challenging due to difficulties in acquiring tiny living mites and breaking their hard chitin. The present study is to explore a better method to construct cDNA library for mites that will lay the foundation on transcriptome and molecular pathogenesis research. We selected Psoroptes cuniculi as an experimental subject and took the following steps to construct and verify cDNA library. First, we combined liquid nitrogen grinding with TRIzol for total RNA extraction. Then, switching mechanism at 5' end of the RNA transcript (SMART) technique was used to construct full-length cDNA library. To evaluate the quality of cDNA library, the library titer and recombination rate were calculated. The reliability of cDNA library was detected by sequencing and analyzing positive clones and genes amplified by specific primers. The results showed that the RNA concentration was 836 ng/μl and the absorbance ratio at 260/280 nm was 1.82. The library titer was 5.31 × 10(5) plaque-forming unit (PFU)/ml and the recombination rate was 98.21%, indicating that the library was of good quality. In the 33 expressed sequence tags (ESTs) of P. cuniculi, two clones of 1656 and 1658 bp were almost identical with only three variable sites detected, which had an identity of 99.63% with that of Psoroptes ovis, indicating that the cDNA library was reliable. Further detection by specific primers demonstrated that the 553-bp Pso c II gene sequences of P. cuniculi had an identity of 98.56% with those of P. ovis, confirming that the cDNA library was not only reliable but also feasible.

  5. High-Throughput Plasmid cDNA Library Screening

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Kenneth H.; Yu, Charles; George, Reed A.; Carlson, JosephW.; Hoskins, Roger A.; Svirskas, Robert; Stapleton, Mark; Celniker, SusanE.

    2006-05-24

    Libraries of cDNA clones are valuable resources foranalysing the expression, structure, and regulation of genes, as well asfor studying protein functions and interactions. Full-length cDNA clonesprovide information about intron and exon structures, splice junctionsand 5'- and 3'-untranslated regions (UTRs). Open reading frames (ORFs)derived from cDNA clones can be used to generate constructs allowingexpression of native proteins and N- or C-terminally tagged proteins.Thus, obtaining full-length cDNA clones and sequences for most or allgenes in an organism is critical for understanding genome functions.Expressed sequence tag (EST) sequencing samples cDNA libraries at random,which is most useful at the beginning of large-scale screening projects.However, as projects progress towards completion, the probability ofidentifying unique cDNAs via EST sequencing diminishes, resulting in poorrecovery of rare transcripts. We describe an adapted, high-throughputprotocol intended for recovery of specific, full-length clones fromplasmid cDNA libraries in five days.

  6. Cloning of the cDNA for human 12-lipoxygenase

    International Nuclear Information System (INIS)

    Izumi, T.; Hoshiko, S.; Radmark, O.; Samuelsson, B.

    1990-01-01

    A full-length cDNA clone encoding 12-lipoxygenase was isolated from a human platelet cDNA library by using a cDNA for human reticulocyte 15-lipoxygenase as probe for the initial screening. The cDNA had an open reading frame encoding 662 amino acid residues with a calculated molecular weight of 75,590. Three independent clones revealed minor heterogeneities in their DNA sequences. Thus, in three positions of the deduced amino acid sequence, there is a choice between two different amino acids. The deduced sequence from the clone plT3 showed 65% identity with human reticulocyte 15-lipoxygenase and 42% identity with human leukocyte 5-lipoxygenase. The 12-lipoxygenase cDNA recognized a 3.0-kilobase mRNA species in platelets and human erythroleukemia cells (HEL cells). Phorbol 12-tetradecanoyl 13-acetate induced megakaryocytic differentiation of HEL cells and 12-lipoxygenase activity and increased mRNA for 12-lipoxygenase. The identity of the cloned 12-lipoxygenase was assured by expression in a mammalian cell line (COS cells). Human platelet 12-lipoxygenase has been difficult to purify to homogeneity. The cloning of this cDNA will increase the possibilities to elucidate the structure and function of this enzyme

  7. The porcelain crab transcriptome and PCAD, the porcelain crab microarray and sequence database.

    Directory of Open Access Journals (Sweden)

    Abderrahmane Tagmount

    Full Text Available BACKGROUND: With the emergence of a completed genome sequence of the freshwater crustacean Daphnia pulex, construction of genomic-scale sequence databases for additional crustacean sequences are important for comparative genomics and annotation. Porcelain crabs, genus Petrolisthes, have been powerful crustacean models for environmental and evolutionary physiology with respect to thermal adaptation and understanding responses of marine organisms to climate change. Here, we present a large-scale EST sequencing and cDNA microarray database project for the porcelain crab Petrolisthes cinctipes. METHODOLOGY/PRINCIPAL FINDINGS: A set of approximately 30K unique sequences (UniSeqs representing approximately 19K clusters were generated from approximately 98K high quality ESTs from a set of tissue specific non-normalized and mixed-tissue normalized cDNA libraries from the porcelain crab Petrolisthes cinctipes. Homology for each UniSeq was assessed using BLAST, InterProScan, GO and KEGG database searches. Approximately 66% of the UniSeqs had homology in at least one of the databases. All EST and UniSeq sequences along with annotation results and coordinated cDNA microarray datasets have been made publicly accessible at the Porcelain Crab Array Database (PCAD, a feature-enriched version of the Stanford and Longhorn Array Databases. CONCLUSIONS/SIGNIFICANCE: The EST project presented here represents the third largest sequencing effort for any crustacean, and the largest effort for any crab species. Our assembly and clustering results suggest that our porcelain crab EST data set is equally diverse to the much larger EST set generated in the Daphnia pulex genome sequencing project, and thus will be an important resource to the Daphnia research community. Our homology results support the pancrustacea hypothesis and suggest that Malacostraca may be ancestral to Branchiopoda and Hexapoda. Our results also suggest that our cDNA microarrays cover as much of the

  8. LNA-modified isothermal oligonucleotide microarray for ...

    Indian Academy of Sciences (India)

    2014-10-20

    Oct 20, 2014 ... To achieve high detection specificity, we fabricated an isothermal microarray ... diagnosis, drug screening, food inspection, agricultural prod- uct monitoring ..... printed with probes B1, B2 and B3 for Bacillus licheniformis (image 1), and microarray analysis of Bacillus licheniformis PCR products amplified ...

  9. Diagnostic and analytical applications of protein microarrays

    DEFF Research Database (Denmark)

    Dufva, Hans Martin; Christensen, C.B.V.

    2005-01-01

    years. A genome-scale protein microarray has been demonstrated for identifying protein-protein interactions as well as for rapid identification of protein binding to a particular drug. Furthermore, protein microarrays have been shown as an efficient tool in cancer profiling, detection of bacteria...

  10. Sequencing and comparative genomics analysis inSenecio scandensBuch.-Ham. Ex D. Don, based on full-length cDNA library.

    Science.gov (United States)

    Qian, Gang; Ping, Junjiao; Zhang, Zhen; Xu, Delin

    2014-09-03

    Senecio scandens Buch.-Ham. ex D. Don, an important antibacterial source of Chinese traditional medicine, has a widespread distribution in a few ecological habitats of China. We generated a full-length complementary DNA (cDNA) library from a sample of elite individuals with superior antibacterial properties, with satisfactory parameters such as library storage (4.30 × 10 6 CFU), efficiency of titre (1.30 × 10 6 CFU/mL), transformation efficiency (96.35%), full-length ratio (64.00%) and redundancy ratio (3.28%). The BLASTN search revealed the facile formation of counterparts between the experimental sample and Arabidopsis thaliana in view of high-homology cDNA sequence (90.79%) with e -values cDNA clones consist of the major of functional genes identified by a large set of microarray data from the present experimental material. For other Compositae species, a large set of full-length cDNA clones reported in the present article will serve as a useful resource to facilitate further research on the transferability of expressed sequence tag-derived simple sequence repeats (EST-SSR) development, comparative genomics and novel transcript profiles.

  11. Isolation of Microarray-Grade Total RNA, MicroRNA, and DNA from a Single PAXgene Blood RNA Tube

    DEFF Research Database (Denmark)

    Kruhøffer, Mogens; Andersen, Lars Dyrskjøt; Voss, Thorsten

    2007-01-01

    We have developed a procedure for isolation of microRNA and genomic DNA in addition to total RNA from whole blood stabilized in PAXgene Blood RNA tubes. The procedure is based on automatic extraction on a BioRobot MDx and includes isolation of DNA from a fraction of the stabilized blood......RNA was tested using spotted locked nucleic acid-based microarrays. We conclude that the yield and quality of total RNA, microRNA, and DNA from a single PAXgene blood RNA tube is sufficient for downstream microarray analysis....

  12. DNA Microarray for Rapid Detection and Identification of Food and Water Borne Bacteria: From Dry to Wet Lab.

    Science.gov (United States)

    Ranjbar, Reza; Behzadi, Payam; Najafi, Ali; Roudi, Raheleh

    2017-01-01

    A rapid, accurate, flexible and reliable diagnostic method may significantly decrease the costs of diagnosis and treatment. Designing an appropriate microarray chip reduces noises and probable biases in the final result. The aim of this study was to design and construct a DNA Microarray Chip for a rapid detection and identification of 10 important bacterial agents. In the present survey, 10 unique genomic regions relating to 10 pathogenic bacterial agents including Escherichia coli (E.coli), Shigella boydii, Sh.dysenteriae, Sh.flexneri, Sh.sonnei, Salmonella typhi, S.typhimurium, Brucella sp., Legionella pneumophila, and Vibrio cholera were selected for designing specific long oligo microarray probes. For this reason, the in-silico operations including utilization of the NCBI RefSeq database, Servers of PanSeq and Gview, AlleleID 7.7 and Oligo Analyzer 3.1 was done. On the other hand, the in-vitro part of the study comprised stages of robotic microarray chip probe spotting, bacterial DNAs extraction and DNA labeling, hybridization and microarray chip scanning. In wet lab section, different tools and apparatus such as Nexterion® Slide E, Qarray mini spotter, NimbleGen kit, TrayMix TM S4, and Innoscan 710 were used. A DNA microarray chip including 10 long oligo microarray probes was designed and constructed for detection and identification of 10 pathogenic bacteria. The DNA microarray chip was capable to identify all 10 bacterial agents tested simultaneously. The presence of a professional bioinformatician as a probe designer is needed to design appropriate multifunctional microarray probes to increase the accuracy of the outcomes.

  13. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  14. Gene ARMADA: an integrated multi-analysis platform for microarray data implemented in MATLAB

    Directory of Open Access Journals (Sweden)

    Kolisis Fragiskos N

    2009-10-01

    Full Text Available Abstract Background The microarray data analysis realm is ever growing through the development of various tools, open source and commercial. However there is absence of predefined rational algorithmic analysis workflows or batch standardized processing to incorporate all steps, from raw data import up to the derivation of significantly differentially expressed gene lists. This absence obfuscates the analytical procedure and obstructs the massive comparative processing of genomic microarray datasets. Moreover, the solutions provided, heavily depend on the programming skills of the user, whereas in the case of GUI embedded solutions, they do not provide direct support of various raw image analysis formats or a versatile and simultaneously flexible combination of signal processing methods. Results We describe here Gene ARMADA (Automated Robust MicroArray Data Analysis, a MATLAB implemented platform with a Graphical User Interface. This suite integrates all steps of microarray data analysis including automated data import, noise correction and filtering, normalization, statistical selection of differentially expressed genes, clustering, classification and annotation. In its current version, Gene ARMADA fully supports 2 coloured cDNA and Affymetrix oligonucleotide arrays, plus custom arrays for which experimental details are given in tabular form (Excel spreadsheet, comma separated values, tab-delimited text formats. It also supports the analysis of already processed results through its versatile import editor. Besides being fully automated, Gene ARMADA incorporates numerous functionalities of the Statistics and Bioinformatics Toolboxes of MATLAB. In addition, it provides numerous visualization and exploration tools plus customizable export data formats for seamless integration by other analysis tools or MATLAB, for further processing. Gene ARMADA requires MATLAB 7.4 (R2007a or higher and is also distributed as a stand-alone application with MATLAB

  15. Gene ARMADA: an integrated multi-analysis platform for microarray data implemented in MATLAB.

    Science.gov (United States)

    Chatziioannou, Aristotelis; Moulos, Panagiotis; Kolisis, Fragiskos N

    2009-10-27

    The microarray data analysis realm is ever growing through the development of various tools, open source and commercial. However there is absence of predefined rational algorithmic analysis workflows or batch standardized processing to incorporate all steps, from raw data import up to the derivation of significantly differentially expressed gene lists. This absence obfuscates the analytical procedure and obstructs the massive comparative processing of genomic microarray datasets. Moreover, the solutions provided, heavily depend on the programming skills of the user, whereas in the case of GUI embedded solutions, they do not provide direct support of various raw image analysis formats or a versatile and simultaneously flexible combination of signal processing methods. We describe here Gene ARMADA (Automated Robust MicroArray Data Analysis), a MATLAB implemented platform with a Graphical User Interface. This suite integrates all steps of microarray data analysis including automated data import, noise correction and filtering, normalization, statistical selection of differentially expressed genes, clustering, classification and annotation. In its current version, Gene ARMADA fully supports 2 coloured cDNA and Affymetrix oligonucleotide arrays, plus custom arrays for which experimental details are given in tabular form (Excel spreadsheet, comma separated values, tab-delimited text formats). It also supports the analysis of already processed results through its versatile import editor. Besides being fully automated, Gene ARMADA incorporates numerous functionalities of the Statistics and Bioinformatics Toolboxes of MATLAB. In addition, it provides numerous visualization and exploration tools plus customizable export data formats for seamless integration by other analysis tools or MATLAB, for further processing. Gene ARMADA requires MATLAB 7.4 (R2007a) or higher and is also distributed as a stand-alone application with MATLAB Component Runtime. Gene ARMADA provides a

  16. Analysis of the Effects of Sex Hormone Background on the Rat Choroid Plexus Transcriptome by cDNA Microarrays

    OpenAIRE

    Quintela, Telma; Gon?alves, Isabel; Carreto, Laura C.; Santos, Manuel A. S.; Marcelino, Helena; Patriarca, Filipa M.; Santos, Cec?lia R. A.

    2013-01-01

    The choroid plexus (CP) are highly vascularized branched structures that protrude into the ventricles of the brain, and form a unique interface between the blood and the cerebrospinal fluid (CSF), the blood-CSF barrier, that are the main site of production and secretion of CSF. Sex hormones are widely recognized as neuroprotective agents against several neurodegenerative diseases, and the presence of sex hormones cognate receptors suggest that it may be a target for these hormones. In an effo...

  17. Molecular characterisation of the early response in pigs to experimental infection with Actinobacillus pleuropneumoniae using cDNA microarrays

    DEFF Research Database (Denmark)

    Hedegaard, Jakob; Skovgaard, Kerstin; Mortensen, Shila

    2007-01-01

    , genes encoding immune activating proteins and other pro-inflammatory mediators of the innate immune response were found to be up-regulated. Genes encoding different acute phase reactants were found to be differentially expressed in the liver. Conclusion: The obtained results are largely in accordance......Background: The bacterium Actinobacillus pleuropneumoniae is responsible for porcine pleuropneumonia, a widespread, highly contagious and often fatal respiratory disease of pigs. The general porcine innate immune response after A. pleuropneumoniae infection is still not clarified. The objective...... with previous studies of the mammalian immune response. Furthermore, a number of differentially expressed genes have not previously been associated with infection or are presently unidentified. Determination of their specific roles during infection may lead to a better understanding of innate immunity in pigs...

  18. Molecular characterisation of the early response in pigs to experimental infection with Actinobacillus pleuropneumoniae using cDNA microarrays

    DEFF Research Database (Denmark)

    Hedegaard, Jakob; Skovgaard, Kerstin; Mortensen, Shila

    2007-01-01

    Background: The bacterium Actinobacillus pleuropneumoniae is responsible for porcine pleuropneumonia, a widespread, highly contagious and often fatal respiratory disease of pigs. The general porcine innate immune response after A. pleuropneumoniae infection is still not clarified. The objective......, genes encoding immune activating proteins and other pro-inflammatory mediators of the innate immune response were found to be up-regulated. Genes encoding different acute phase reactants were found to be differentially expressed in the liver. Conclusion: The obtained results are largely in accordance...... with previous studies of the mammalian immune response. Furthermore, a number of differentially expressed genes have not previously been associated with infection or are presently unidentified. Determination of their specific roles during infection may lead to a better understanding of innate immunity in pigs...

  19. Sample size for detecting differentially expressed genes in microarray experiments

    Directory of Open Access Journals (Sweden)

    Li Jiangning

    2004-11-01

    Full Text Available Abstract Background Microarray experiments are often performed with a small number of biological replicates, resulting in low statistical power for detecting differentially expressed genes and concomitant high false positive rates. While increasing sample size can increase statistical power and decrease error rates, with too many samples, valuable resources are not used efficiently. The issue of how many replicates are required in a typical experimental system needs to be addressed. Of particular interest is the difference in required sample sizes for similar experiments in inbred vs. outbred populations (e.g. mouse and rat vs. human. Results We hypothesize that if all other factors (assay protocol, microarray platform, data pre-processing were equal, fewer individuals would be needed for the same statistical power using inbred animals as opposed to unrelated human subjects, as genetic effects on gene expression will be removed in the inbred populations. We apply the same normalization algorithm and estimate the variance of gene expression for a variety of cDNA data sets (humans, inbred mice and rats comparing two conditions. Using one sample, paired sample or two independent sample t-tests, we calculate the sample sizes required to detect a 1.5-, 2-, and 4-fold changes in expression level as a function of false positive rate, power and percentage of genes that have a standard deviation below a given percentile. Conclusions Factors that affect power and sample size calculations include variability of the population, the desired detectable differences, the power to detect the differences, and an acceptable error rate. In addition, experimental design, technical variability and data pre-processing play a role in the power of the statistical tests in microarrays. We show that the number of samples required for detecting a 2-fold change with 90% probability and a p-value of 0.01 in humans is much larger than the number of samples commonly used in

  20. Expression profiling using a hexamer-based universal microarray.

    Science.gov (United States)

    Roth, Matthew E; Feng, Li; McConnell, Kevin J; Schaffer, Paul J; Guerra, Cesar E; Affourtit, Jason P; Piper, Kevin R; Guccione, Lorri; Hariharan, Jayashree; Ford, Maura J; Powell, Stephen W; Krishnaswamy, Harish; Lane, Jennifer; Guccione, Lisa; Intrieri, Gino; Merkel, Jane S; Perbost, Clotilde; Valerio, Anthony; Zolla, Brenda; Graham, Carol D; Hnath, Jonathan; Michaelson, Chris; Wang, Rixin; Ying, Baoge; Halling, Conrad; Parman, Craig E; Raha, Debasish; Orr, Brent; Jedrzkiewicz, Barbara; Liao, Ji; Tevelev, Anton; Mattessich, Martin J; Kranz, David M; Lacey, Michelle; Kaufman, Joseph C; Kim, Junhyong; Latimer, Darin R; Lizardi, Paul M

    2004-04-01

    We describe a transcriptional analysis platform consisting of a universal micro-array system (UMAS) combined with an enzymatic manipulation step that is capable of generating expression profiles from any organism without requiring a priori species-specific knowledge of transcript sequences. The transcriptome is converted to cDNA and processed with restriction endonucleases to generate low-complexity pools (approximately 80-120) of equal length DNA fragments. The resulting material is amplified and detected with the UMAS system, comprising all possible 4,096 (4(6)) DNA hexamers. Ligation to the arrays yields thousands of 14-mer sequence tags. The compendium of signals from all pools in the array-of-universal arrays comprises a full-transcriptome expression profile. The technology was validated by analysis of the galactose response of Saccharomyces cerevisiae, and the resulting profiles showed excellent agreement with the literature and real-time PCR assays. The technology was also used to demonstrate expression profiling from a hybrid organism in a proof-of-concept experiment where a T-cell receptor gene was expressed in yeast.

  1. High quality epoxysilane substrate for clinical multiplex serodiagnostic proteomic microarrays

    Science.gov (United States)

    Ewart, Tom; Carmichael, Stuart; Lea, Peter

    2005-09-01

    Polylysine and aminopropylsilane treated glass comprised the majority of substrates employed in first generation genetic microarray substrates. Second generation single stranded long oligo libraries with amino termini provided for controlled terminal specific attachment, and rationally designed unique sequence libraries with normalized melting temperatures. These libraries benefit from active covalent coupling surfaces such as Epoxysilane. The latter's oxime ring shows versatile reactivity with amino-, thiol- and hydroxyl- groups thus encompassing small molecule, oligo and proteomic microarray applications. Batch-to-batch production uniformity supports entry of the Epoxysilane process into clinical diagnostics. We carried out multiple print runs of 21 clinically relevant bacterial and viral antigens at optimized concentrations, plus human IgG and IgM standards in triplicate on multiple batches of Epoxysilane substrates. A set of 45 patient sera were assayed in a 35 minute protocol using 10 microliters per array in a capillary-fill format (15 minute serum incubation, wash, 15 minute incubation with Cy3-labeled anti-hIgG plus Dy647-labeled anti-hIgM, final wash). The LOD (3 SD above background) was better than 1 microgram/ml for IgG, and standard curves were regular and monotonically increasing over the range 0 to 1000 micrograms/ml. Ninety-five percent of the CVs for the standards were under 10%, and 90% percent of CVs for antigen responses were under 10% across all batches of Epoxysilane and print runs. In addition, where SDs are larger than expected, microarray images may be readily reviewed for quality control purposes and pin misprints quickly identified. In order to determine the influence of stirring on sensitivity and speed of the microarray assay, we printed 10 common ToRCH antigens (H. pylori, T. gondii, Rubella, Rubeola, C. trachomatis, Herpes 1 and 2, CMV, C. jejuni, and EBV) in Epoxysilane-activated slide-wells. Anti-IgG-Cy3 direct binding to printed Ig

  2. Focused Screening of ECM-Selective Adhesion Peptides on Cellulose-Bound Peptide Microarrays

    Directory of Open Access Journals (Sweden)

    Kei Kanie

    2016-11-01

    Full Text Available The coating of surfaces with bio-functional proteins is a promising strategy for the creation of highly biocompatible medical implants. Bio-functional proteins from the extracellular matrix (ECM provide effective surface functions for controlling cellular behavior. We have previously screened bio-functional tripeptides for feasibility of mass production with the aim of identifying those that are medically useful, such as cell-selective peptides. In this work, we focused on the screening of tripeptides that selectively accumulate collagen type IV (Col IV, an ECM protein that accelerates the re-endothelialization of medical implants. A SPOT peptide microarray was selected for screening owing to its unique cellulose membrane platform, which can mimic fibrous scaffolds used in regenerative medicine. However, since the library size on the SPOT microarray was limited, physicochemical clustering was used to provide broader variation than that of random peptide selection. Using the custom focused microarray of 500 selected peptides, we assayed the relative binding rates of tripeptides to Col IV, collagen type I (Col I, and albumin. We discovered a cluster of Col IV-selective adhesion peptides that exhibit bio-safety with endothelial cells. The results from this study can be used to improve the screening of regeneration-enhancing peptides.

  3. cDNA library Table - KAIKOcDNA | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data List Contact us KAIKOcDNA... cDNA library Table Data detail Data name cDNA library Table DOI 10.18908/lsdba.nbd...c00951-005 Description of data contents List of Bombyx mori cDNA libraries. Data file File name: kaiko_cdna_...iption Registered library name Registered name of the partial cDNA library Library synonym Another name for cDNA... Download License Update History of This Database Site Policy | Contact Us cDNA library Table - KAIKOcDNA | LSDB Archive ...

  4. Study on construction of cDNA library of the treated changliver cell and quality analysis

    OpenAIRE

    Juntang, Lin; Pramanik, Jogenananda; Congrui, Wang; Huiyong, Zhang; Huigen, Feng; Baosheng, Yang; Yuchang, Li; Cunshuan, Xu

    2004-01-01

    The study aims to construct cDNA library of Changliver cell by SMART (switching mechanism at 5′ end of RNA transcript) technique and analyze its quality. cDNA of Changliver cell was made with RT-PCR and LD-PCR (long-distance PCR), the cDNA library was constructed with SMART cDNA library construction kit. Through testing, the high quality cDNA library containing whole long cDNA of Changliver cell had been constructed. The titer of the amplified cDNA library was 4.5 × 1010 pfu/ml and the averag...

  5. MARS: Microarray analysis, retrieval, and storage system

    Directory of Open Access Journals (Sweden)

    Scheideler Marcel

    2005-04-01

    Full Text Available Abstract Background Microarray analysis has become a widely used technique for the study of gene-expression patterns on a genomic scale. As more and more laboratories are adopting microarray technology, there is a need for powerful and easy to use microarray databases facilitating array fabrication, labeling, hybridization, and data analysis. The wealth of data generated by this high throughput approach renders adequate database and analysis tools crucial for the pursuit of insights into the transcriptomic behavior of cells. Results MARS (Microarray Analysis and Retrieval System provides a comprehensive MIAME supportive suite for storing, retrieving, and analyzing multi color microarray data. The system comprises a laboratory information management system (LIMS, a quality control management, as well as a sophisticated user management system. MARS is fully integrated into an analytical pipeline of microarray image analysis, normalization, gene expression clustering, and mapping of gene expression data onto biological pathways. The incorporation of ontologies and the use of MAGE-ML enables an export of studies stored in MARS to public repositories and other databases accepting these documents. Conclusion We have developed an integrated system tailored to serve the specific needs of microarray based research projects using a unique fusion of Web based and standalone applications connected to the latest J2EE application server technology. The presented system is freely available for academic and non-profit institutions. More information can be found at http://genome.tugraz.at.

  6. Annotating breast cancer microarray samples using ontologies

    Science.gov (United States)

    Liu, Hongfang; Li, Xin; Yoon, Victoria; Clarke, Robert

    2008-01-01

    As the most common cancer among women, breast cancer results from the accumulation of mutations in essential genes. Recent advance in high-throughput gene expression microarray technology has inspired researchers to use the technology to assist breast cancer diagnosis, prognosis, and treatment prediction. However, the high dimensionality of microarray experiments and public access of data from many experiments have caused inconsistencies which initiated the development of controlled terminologies and ontologies for annotating microarray experiments, such as the standard microarray Gene Expression Data (MGED) ontology (MO). In this paper, we developed BCM-CO, an ontology tailored specifically for indexing clinical annotations of breast cancer microarray samples from the NCI Thesaurus. Our research showed that the coverage of NCI Thesaurus is very limited with respect to i) terms used by researchers to describe breast cancer histology (covering 22 out of 48 histology terms); ii) breast cancer cell lines (covering one out of 12 cell lines); and iii) classes corresponding to the breast cancer grading and staging. By incorporating a wider range of those terms into BCM-CO, we were able to indexed breast cancer microarray samples from GEO using BCM-CO and MGED ontology and developed a prototype system with web interface that allows the retrieval of microarray data based on the ontology annotations. PMID:18999108

  7. cDNA library construction of two human Demodexspecies.

    Science.gov (United States)

    Niu, DongLing; Wang, RuiLing; Zhao, YaE; Yang, Rui; Hu, Li; Lei, YuYang; Dan, WeiChao

    2017-06-01

    The research of Demodex, a type of pathogen causing various dermatoses in animals and human beings, is lacking at RNA level. This study aims at extracting RNA and constructing cDNA library for Demodex. First, P. cuniculiand D. farinaewere mixed to establish homogenization method for RNA extraction. Second, D. folliculorumand D. breviswere collected and preserved in Trizol, which were mixed with D. farinaerespectively to extract RNA. Finally, cDNA library was constructed and its quality was assessed. The results indicated that for D. folliculorum& D. farinae, the recombination rate of cDNA library was 90.67% and the library titer was 7.50 × 104 pfu/ml. 17 of the 59 positive clones were predicted to be of D. folliculorum; For D. brevis& D. farinae, the recombination rate was 90.96% and the library titer was 7.85 x104 pfu/ml. 40 of the 59 positive clones were predicted to be of D. brevis. Further detection by specific primers demonstrated that mtDNA cox1, cox3and ATP6 detected from cDNA libraries had 96.52%-99.73% identities with the corresponding sequences in GenBank. In conclusion, the cDNA libraries constructed for Demodexmixed with D. farinaewere successful and could satisfy the requirements for functional genes detection.

  8. Second-strand cDNA synthesis: classical method

    International Nuclear Information System (INIS)

    Gubler, U.

    1987-01-01

    The classical scheme for the synthesis of double-stranded cDNA as it was reported in 1976 is described. Reverse transcription of mRNA with oligo(dT) as the primer generates first strands with a small loop at the 3' end of the cDNA (the end that corresponds to the 5' end of the mRNA). Subsequent removal of the mRNA by alkaline hydrolysis leaves single-stranded cDNA molecules again with a small 3' loop. This loop can be used by either reverse transcriptase or Klenow fragment of DNA polymerase I as a primer for second-strand synthesis. The resulting products are double-stranded cDNA molecules that are covalently closed at the end corresponding to the 5' end of the original mRNA. Subsequent cleavage of the short piece of single-stranded cDNA within the loop with the single-strand-specific S 1 nuclease generate open double-stranded molecules that can be used for molecular cloning in plasmids or in phage. Useful variations of this scheme have been described

  9. Applications of heparin and heparan sulfate microarrays.

    Science.gov (United States)

    Yin, Jian; Seeberger, Peter H

    2010-01-01

    Carbohydrate microarrays have become crucial tools for revealing the biological interactions and functions of glycans, primarily because the microarray format enables the investigation of large numbers of carbohydrates at a time. Heparan sulfate (HS) and heparin are the most structurally complex glycosaminoglycans (GAGs). In this chapter, we describe the preparation of a small library of HS/heparin oligosaccharides, and the fabrication of HS/heparin microarrays that have been used to establish HS/heparin-binding profiles. Fibroblast growth factors (FGFs), natural cytotoxicity receptors (NCRs), and chemokines were screened to illuminate the very important biological functions of these glycans. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  10. Fuzzy clustering analysis of microarray data.

    Science.gov (United States)

    Han, Lixin; Zeng, Xiaoqin; Yan, Hong

    2008-10-01

    Fuzzy clustering is a useful tool for identifying relevant subsets of microarray data. This paper proposes a fuzzy clustering method for microarray data analysis. An advantage of the method is that it used a combination of the fuzzy c-means and the principal component analysis to identify the groups of genes that show similar expression patterns. It allows a gene to belong to more than a gene expression pattern with different membership grades. The method is suitable for the analysis of large amounts of noisy microarray data.

  11. Metric learning for DNA microarray data analysis

    International Nuclear Information System (INIS)

    Takeuchi, Ichiro; Nakagawa, Masao; Seto, Masao

    2009-01-01

    In many microarray studies, gene set selection is an important preliminary step for subsequent main task such as tumor classification, cancer subtype identification, etc. In this paper, we investigate the possibility of using metric learning as an alternative to gene set selection. We develop a simple metric learning algorithm aiming to use it for microarray data analysis. Exploiting a property of the algorithm, we introduce a novel approach for extending the metric learning to be adaptive. We apply the algorithm to previously studied microarray data on malignant lymphoma subtype identification.

  12. Pineal function: impact of microarray analysis

    DEFF Research Database (Denmark)

    Klein, David C; Bailey, Michael J; Carter, David A

    2009-01-01

    Microarray analysis has provided a new understanding of pineal function by identifying genes that are highly expressed in this tissue relative to other tissues and also by identifying over 600 genes that are expressed on a 24-h schedule. This effort has highlighted surprising similarity to the re......Microarray analysis has provided a new understanding of pineal function by identifying genes that are highly expressed in this tissue relative to other tissues and also by identifying over 600 genes that are expressed on a 24-h schedule. This effort has highlighted surprising similarity...... foundation that microarray analysis has provided will broadly support future research on pineal function....

  13. A study of inter-lab and inter-platform agreement of DNA microarray data

    Directory of Open Access Journals (Sweden)

    Wilson Carole

    2005-05-01

    Full Text Available Abstract As gene expression profile data from DNA microarrays accumulate rapidly, there is a natural need to compare data across labs and platforms. Comparisons of microarray data can be quite challenging due to data complexity and variability. Different labs may adopt different technology platforms. One may ask about the degree of agreement we can expect from different labs and different platforms. To address this question, we conducted a study of inter-lab and inter-platform agreement of microarray data across three platforms and three labs. The statistical measures of consistency and agreement used in this paper are the Pearson correlation, intraclass correlation, kappa coefficients, and a measure of intra-transcript correlation. The three platforms used in the present paper were Affymetrix GeneChip, custom cDNA arrays, and custom oligo arrays. Using the within-platform variability as a benchmark, we found that these technology platforms exhibited an acceptable level of agreement, but the agreement between two technologies within the same lab was greater than that between two labs using the same technology. The consistency of replicates in each experiment varies from lab to lab. When there is high consistency among replicates, different technologies show good agreement within and across labs using the same RNA samples. On the other hand, the lab effect, especially when confounded with the RNA sample effect, plays a bigger role than the platform effect on data agreement.

  14. Microarray analysis of gene expression in disk abalone Haliotis discus discus after bacterial challenge.

    Science.gov (United States)

    De Zoysa, Mahanama; Nikapitiya, Chamilani; Oh, Chulhong; Lee, Youngdeuk; Whang, Ilson; Lee, Jae-Seong; Choi, Cheol Young; Lee, Jehee

    2011-02-01

    In this study, we investigated the gene expression profiling of disk abalone, Haliotis discus discus challenged by a mixture of three pathogenic bacteria Vibrio alginolyticus, Vibrio parahemolyticus, and Listeria monocytogenes using a cDNA microarray. Upon bacteria challenge, 68 (1.6%) and 112 (2.7%) gene transcripts changed their expression levels ≥2 or ≤2 -fold in gills and digestive tract, respectively. There were 46 tissue-specific transcripts that up-regulated specifically in the digestive tract. In contrast, only 13 transcripts showed gill-specific up-regulation. Quantitative real-time PCR was performed to verify microarray data and results revealed that candidate genes namely Krüppell-like factor (KLF), lachesin, muscle lim protein, thioredoxin-2 (TRx-2), nuclear factor interleukin 3 (NFIL-3) and abalone protein 38 were up-regulated. Also, our results further indicated that bacteria challenge may activate the transcription factors or their activators (Krüppell-like factor, inhibitor of NF-κB or Ik-B), inflammatory cytokines (IL-3 regulated protein, allograft inflammatory factor), other cytokines (IFN-44-like protein, SOCS-2), antioxidant enzymes (glutathione-S-transferase, thioredoxin-2 and thioredoxin peroxidase), and apoptosis-related proteins (TNF-α, archeron) in abalone. The identification of immune and stress response genes and their expression profiles in this microarray will permit detailed investigation of the stress and immune responses of abalone genes. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. White-spot Lesions and Gingivitis Microbiotas in Orthodontic Patients

    Science.gov (United States)

    Tanner, A.C.R.; Sonis, A.L.; Lif Holgerson, P.; Starr, J.R.; Nunez, Y.; Kressirer, C.A.; Paster, B.J.; Johansson, I.

    2012-01-01

    White-spot lesions (WSL) associated with orthodontic appliances are a cosmetic problem and increase risk for cavities. We characterized the microbiota of WSL, accounting for confounding due to gingivitis. Participants were 60 children with fixed appliances, aged between 10 and 19 yrs, half with WSL. Plaque samples were assayed by a 16S rRNA-based microarray (HOMIM) and by PCR. Mean gingival index was positively associated with WSL (p = 0.018). Taxa associated with WSL by microarray included Granulicatella elegans (p = 0.01), Veillonellaceae sp. HOT 155 (p gingivitis by microarray included: Gemella sanguinis (p = 0.002), Actinomyces sp. HOT 448 (p = 0.003), Prevotella cluster IV (p = 0.021), and Streptococcus sp. HOT 071/070 (p = 0.023); and levels of S. mutans (p = 0.02) and Bifidobacteriaceae (p = 0.012) by qPCR. Species’ associations with WSL were minimally changed with adjustment for gingivitis level. Partial least-squares discriminant analysis yielded good discrimination between children with and those without WSL. Granulicatella, Veillonellaceae and Bifidobacteriaceae, in addition to S. mutans and S. wiggsiae, were associated with the presence of WSL in adolescents undergoing orthodontic treatment. Many taxa showed a stronger association with gingivitis than with WSL. PMID:22837552

  16. Evolution of the MIDTAL microarray: the adaption and testing of oligonucleotide 18S and 28S rDNA probes and evaluation of subsequent microarray generations with Prymnesium spp. cultures and field samples.

    Science.gov (United States)

    McCoy, Gary R; Touzet, Nicolas; Fleming, Gerard T A; Raine, Robin

    2015-07-01

    The toxic microalgal species Prymnesium parvum and Prymnesium polylepis are responsible for numerous fish kills causing economic stress on the aquaculture industry and, through the consumption of contaminated shellfish, can potentially impact on human health. Monitoring of toxic phytoplankton is traditionally carried out by light microscopy. However, molecular methods of identification and quantification are becoming more common place. This study documents the optimisation of the novel Microarrays for the Detection of Toxic Algae (MIDTAL) microarray from its initial stages to the final commercial version now available from Microbia Environnement (France). Existing oligonucleotide probes used in whole-cell fluorescent in situ hybridisation (FISH) for Prymnesium species from higher group probes to species-level probes were adapted and tested on the first-generation microarray. The combination and interaction of numerous other probes specific for a whole range of phytoplankton taxa also spotted on the chip surface caused high cross reactivity, resulting in false-positive results on the microarray. The probe sequences were extended for the subsequent second-generation microarray, and further adaptations of the hybridisation protocol and incubation temperatures significantly reduced false-positive readings from the first to the second-generation chip, thereby increasing the specificity of the MIDTAL microarray. Additional refinement of the subsequent third-generation microarray protocols with the addition of a poly-T amino linker to the 5' end of each probe further enhanced the microarray performance but also highlighted the importance of optimising RNA labelling efficiency when testing with natural seawater samples from Killary Harbour, Ireland.

  17. cDNA libraries for virus-induced gene silencing.

    Science.gov (United States)

    Todd, Andrea T; Liu, Enwu; Page, Jonathan E

    2010-01-01

    Virus-induced gene silencing (VIGS) exploits endogenous plant antiviral defense mechanisms to posttranscriptionally silence the expression of targeted plant genes. VIGS is quick and relatively easy to perform and therefore serves as a powerful tool for high-throughput functional genomics in plants. Combined with the use of subtractive cDNA libraries for generating a collection of VIGS-ready cDNA inserts, VIGS can be utilized to screen a large number of genes to determine phenotypes resulting from the knockdown/knockout of gene function. Taking into account the optimal insert design for VIGS, we describe a methodology for producing VIGS-ready cDNA libraries enriched for inserts relevant to the biological process of interest.

  18. Procedure for normalization of cDNA libraries

    Science.gov (United States)

    Bonaldo, Maria DeFatima; Soares, Marcelo Bento

    1997-01-01

    This invention provides a method to normalize a cDNA library constructed in a vector capable of being converted to single-stranded circles and capable of producing complementary nucleic acid molecules to the single-stranded circles comprising: (a) converting the cDNA library in single-stranded circles; (b) generating complementary nucleic acid molecules to the single-stranded circles; (c) hybridizing the single-stranded circles converted in step (a) with complementary nucleic acid molecules of step (b) to produce partial duplexes to an appropriate Cot; (e) separating the unhybridized single-stranded circles from the hybridized single-stranded circles, thereby generating a normalized cDNA library.

  19. Simultaneous Detection of Multiple Fish Pathogens Using a Naked-Eye Readable DNA Microarray

    Directory of Open Access Journals (Sweden)

    King-Jung Lin

    2012-02-01

    Full Text Available We coupled 16S rDNA PCR and DNA hybridization technology to construct a microarray for simultaneous detection and discrimination of eight fish pathogens (Aeromonas hydrophila, Edwardsiella tarda, Flavobacterium columnare, Lactococcus garvieae, Photobacterium damselae, Pseudomonas anguilliseptica, Streptococcus iniae and Vibrio anguillarum commonly encountered in aquaculture. The array comprised short oligonucleotide probes (30 mer complementary to the polymorphic regions of 16S rRNA genes for the target pathogens. Targets annealed to the microarray probes were reacted with streptavidin-conjugated alkaline phosphatase and nitro blue tetrazolium/5-bromo-4-chloro-3′-indolylphosphate, p-toluidine salt (NBT/BCIP, resulting in blue spots that are easily visualized by the naked eye. Testing was performed against a total of 168 bacterial strains, i.e., 26 representative collection strains, 81 isolates of target fish pathogens, and 61 ecologically or phylogenetically related strains. The results showed that each probe consistently identified its corresponding target strain with 100% specificity. The detection limit of the microarray was estimated to be in the range of 1 pg for genomic DNA and 103 CFU/mL for pure pathogen cultures. These high specificity and sensitivity results demonstrate the feasibility of using DNA microarrays in the diagnostic detection of fish pathogens.

  20. 3D Biomaterial Microarrays for Regenerative Medicine

    DEFF Research Database (Denmark)

    Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars

    2015-01-01

    Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem...

  1. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  2. PATMA: parser of archival tissue microarray

    Directory of Open Access Journals (Sweden)

    Lukasz Roszkowiak

    2016-12-01

    Full Text Available Tissue microarrays are commonly used in modern pathology for cancer tissue evaluation, as it is a very potent technique. Tissue microarray slides are often scanned to perform computer-aided histopathological analysis of the tissue cores. For processing the image, splitting the whole virtual slide into images of individual cores is required. The only way to distinguish cores corresponding to specimens in the tissue microarray is through their arrangement. Unfortunately, distinguishing the correct order of cores is not a trivial task as they are not labelled directly on the slide. The main aim of this study was to create a procedure capable of automatically finding and extracting cores from archival images of the tissue microarrays. This software supports the work of scientists who want to perform further image processing on single cores. The proposed method is an efficient and fast procedure, working in fully automatic or semi-automatic mode. A total of 89% of punches were correctly extracted with automatic selection. With an addition of manual correction, it is possible to fully prepare the whole slide image for extraction in 2 min per tissue microarray. The proposed technique requires minimum skill and time to parse big array of cores from tissue microarray whole slide image into individual core images.

  3. Diagnostic and analytical applications of protein microarrays.

    Science.gov (United States)

    Dufva, Martin; Christensen, Claus B V

    2005-01-01

    DNA microarrays have changed the field of biomedical sciences over the past 10 years. For several reasons, antibody and other protein microarrays have not developed at the same rate. However, protein and antibody arrays have emerged as a powerful tool to complement DNA microarrays during the past 5 years. A genome-scale protein microarray has been demonstrated for identifying protein-protein interactions as well as for rapid identification of protein binding to a particular drug. Furthermore, protein microarrays have been shown as an efficient tool in cancer profiling, detection of bacteria and toxins, identification of allergen reactivity and autoantibodies. They have also demonstrated the ability to measure the absolute concentration of small molecules. Besides their capacity for parallel diagnostics, microarrays can be more sensitive than traditional methods such as enzyme-linked immunosorbent assay, mass spectrometry or high-performance liquid chromatography-based assays. However, for protein and antibody arrays to be successfully introduced into diagnostics, the biochemistry of immunomicroarrays must be better characterized and simplified, they must be validated in a clinical setting and be amenable to automation or integrated into easy-to-use systems, such as micrototal analysis systems or point-of-care devices.

  4. Contributions to Statistical Problems Related to Microarray Data

    Science.gov (United States)

    Hong, Feng

    2009-01-01

    Microarray is a high throughput technology to measure the gene expression. Analysis of microarray data brings many interesting and challenging problems. This thesis consists three studies related to microarray data. First, we propose a Bayesian model for microarray data and use Bayes Factors to identify differentially expressed genes. Second, we…

  5. In-depth cDNA library sequencing provides quantitative gene expression profiling in cancer biomarker discovery.

    Science.gov (United States)

    Yang, Wanling; Ying, Dingge; Lau, Yu-Lung

    2009-06-01

    Quantitative gene expression analysis plays an important role in identifying differentially expressed genes in various pathological states, gene expression regulation and co-regulation, shedding light on gene functions. Although microarray is widely used as a powerful tool in this regard, it is suboptimal quantitatively and unable to detect unknown gene variants. Here we demonstrated effective detection of differential expression and co-regulation of certain genes by expressed sequence tag analysis using a selected subset of cDNA libraries. We discussed the issues of sequencing depth and library preparation, and propose that increased sequencing depth and improved preparation procedures may allow detection of many expression features for less abundant gene variants. With the reduction of sequencing cost and the emerging of new generation sequencing technology, in-depth sequencing of cDNA pools or libraries may represent a better and powerful tool in gene expression profiling and cancer biomarker detection. We also propose using sequence-specific subtraction to remove hundreds of the most abundant housekeeping genes to increase sequencing depth without affecting relative expression ratio of other genes, as transcripts from as few as 300 most abundantly expressed genes constitute about 20% of the total transcriptome. In-depth sequencing also represents a unique advantage of detecting unknown forms of transcripts, such as alternative splicing variants, fusion genes, and regulatory RNAs, as well as detecting mutations and polymorphisms that may play important roles in disease pathogenesis.

  6. Spotting and validation of a genome wide oligonucleotide chip with duplicate measurement of each gene

    International Nuclear Information System (INIS)

    Thomassen, Mads; Skov, Vibe; Eiriksdottir, Freyja; Tan, Qihua; Jochumsen, Kirsten; Fritzner, Niels; Brusgaard, Klaus; Dahlgaard, Jesper; Kruse, Torben A.

    2006-01-01

    The quality of DNA microarray based gene expression data relies on the reproducibility of several steps in a microarray experiment. We have developed a spotted genome wide microarray chip with oligonucleotides printed in duplicate in order to minimise undesirable biases, thereby optimising detection of true differential expression. The validation study design consisted of an assessment of the microarray chip performance using the MessageAmp and FairPlay labelling kits. Intraclass correlation coefficient (ICC) was used to demonstrate that MessageAmp was significantly more reproducible than FairPlay. Further examinations with MessageAmp revealed the applicability of the system. The linear range of the chips was three orders of magnitude, the precision was high, as 95% of measurements deviated less than 1.24-fold from the expected value, and the coefficient of variation for relative expression was 13.6%. Relative quantitation was more reproducible than absolute quantitation and substantial reduction of variance was attained with duplicate spotting. An analysis of variance (ANOVA) demonstrated no significant day-to-day variation

  7. The monitoring of gene functions on a cell-defined siRNA microarray in human bone marrow stromal and U2OS cells

    Directory of Open Access Journals (Sweden)

    Hi Chul Kim

    2016-06-01

    Full Text Available Here, we developed a cell defined siRNA microarray (CDSM for human bone marrow stromal cells (hBMSCs designed to control the culture of cells inside the spot area without reducing the efficiency of siRNA silencing, “Development of a cell-defined siRNA microarray for analysis of gene functionin human bone marrow stromal cells” (Kim et al., 2016 [1]. First, we confirmed that p65 protein inhibition efficiency was maintained when hBMSCs were culture for 7 days on the siRNA spot, and siRNA spot activity remained in spite of long term storage (10 days and 2 months. Additionally, we confirmed p65 protein inhibition in U2OS cells after 48 h reverse transfection.

  8. Cloning, sequencing and expression of cDNA encoding growth ...

    Indian Academy of Sciences (India)

    Unknown

    cell embryo and the expression was monitored continuously. The expression shown here is in developing embryo and freshly hatched fish. The intensity of green colour indicate the strong expression of EGFP in all the tissues of the embryo/fry. The expression of EGPF indicates the co-expression of catfish GH cDNA and the ...

  9. cDNA cloning, structural analysis, SNP detection and tissue ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 96; Issue 2. cDNA cloning, structural analysis, SNP detection and tissue ... Abstract. Insulin-like growth factor 1 (IGF1) plays an important role in growth, reproduction, foetal development and cell proliferation. The present study was conducted to clone and sequence the ...

  10. Cloning and characterization of cDNA encoding xyloglucan ...

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... construction and restructuring of xyloglucan cross-links, thereby controlling the mechanical properties of cell wall. We cloned complete cDNA of an ..... are marked by horizontal lines. The conserved cysteine residues (amino acids 220, 229, 274 and 288 in P. glaucum) are marked by vertical blue arrows.

  11. cDNA, genomic sequence cloning and overexpression of ribosomal ...

    African Journals Online (AJOL)

    RPS16 of eukaryote is a component of the 40S small ribosomal subunit encoded by RPS16 gene and is also a homolog of prokaryotic RPS9. The cDNA and genomic sequence of RPS16 was cloned successfully for the first time from the Giant Panda (Ailuropoda melanoleuca) using reverse transcription-polymerase chain ...

  12. cDNA cloning, structural analysis, SNP detection and tissue ...

    Indian Academy of Sciences (India)

    THOMAS NAICY

    [Naicy T., Venkatachalapathy T., Aravindakshan T., Raghavan K. C., Mini M. and Shyama K. 2017 cDNA cloning, structural analysis, SNP detection and tissue expression profile of the IGF1 gene in Malabari and Attappady Black goats of India. J. Genet. 96, xx–xx]. Introduction. Insulin-like growth factor 1 (IGF1), an important ...

  13. Construction of yeast surface-displayed cDNA libraries.

    Science.gov (United States)

    Bidlingmaier, Scott; Liu, Bin

    2011-01-01

    Using yeast display, heterologous protein fragments can be efficiently displayed at high copy levels on the Saccharomyces cerevisiae cell wall. Yeast display can be used to screen large expressed protein libraries for proteins or protein fragments with specific binding properties. Recently, yeast surface-displayed cDNA libraries have been constructed and used to identify proteins that bind to various target molecules such as peptides, small molecules, and antibodies. Because yeast protein expression pathways are similar to those found in mammalian cells, human protein fragments displayed on the yeast cell wall are likely to be properly folded and functional. Coupled with fluorescence-activated cell sorting, yeast surface-displayed cDNA libraries potentially allow the selection of protein fragments or domains with affinity for any soluble molecule that can be fluorescently detected. In this report, we describe protocols for the construction and validation of yeast surface-displayed cDNA libraries using preexisting yeast two-hybrid cDNA libraries as a starting point.

  14. A BIOINFORMATIC STRATEGY TO RAPIDLY CHARACTERIZE CDNA LIBRARIES

    Science.gov (United States)

    A Bioinformatic Strategy to Rapidly Characterize cDNA LibrariesG. Charles Ostermeier1, David J. Dix2 and Stephen A. Krawetz1.1Departments of Obstetrics and Gynecology, Center for Molecular Medicine and Genetics, & Institute for Scientific Computing, Wayne State Univer...

  15. Development of a predictor for human brain tumors based on gene expression values obtained from two types of microarray technologies.

    Science.gov (United States)

    Castells, Xavier; Acebes, Juan José; Boluda, Susana; Moreno-Torres, Angel; Pujol, Jesús; Julià-Sapé, Margarida; Candiota, Ana Paula; Ariño, Joaquín; Barceló, Anna; Arús, Carles

    2010-04-01

    Development of molecular diagnostics that can reliably differentiate amongst different subtypes of brain tumors is an important unmet clinical need in postgenomics medicine and clinical oncology. A simple linear formula derived from gene expression values of four genes (GFAP, PTPRZ1, GPM6B, and PRELP) measured from cDNA microarrays (n = 35) have distinguished glioblastoma and meningioma cases in a previous study. We herein extend this work further and report that the above predictor formula showed its robustness when applied to Affymetrix microarray data acquired prospectively in our laboratory (n = 80) as well as publicly available data (n = 98). Importantly, GFAP and GPM6B were both retained as being significant in the predictive model upon using the Affymetrix data obtained in our laboratory, whereas the other two predictor genes were SFRP2 and SLC6A2. These results collectively indicate the importance of the expression values of GFAP and GPM6B genes sampled from the two types of microarray technologies tested. The high prediction accuracy obtained in these instances demonstrates the robustness of the predictors across microarray platforms used. This result would require further validation with a larger population of meningioma and glioblastoma cases. At any rate, this study paves the way for further application of gene signatures to more stringent biopsy discrimination challenges.

  16. Inter-Platform comparability of microarrays in acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Mintz Michelle

    2004-09-01

    for prognostic variables. We have also been able to validate the gene predictors with high accuracy using an independent dataset generated on cDNA arrays. Conclusion Interarray comparisons such as this one will further enhance the ability to integrate data from several generations of microarray experiments and will help to break down barriers to the assimilation of existing datasets into a comprehensive data pool.

  17. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  18. Anti-CD antibody microarray for human leukocyte morphology examination allows analyzing rare cell populations and suggesting preliminary diagnosis in leukemia.

    Science.gov (United States)

    Khvastunova, Alina N; Kuznetsova, Sofya A; Al-Radi, Liubov S; Vylegzhanina, Alexandra V; Zakirova, Anna O; Fedyanina, Olga S; Filatov, Alexander V; Vorobjev, Ivan A; Ataullakhanov, Fazly

    2015-07-27

    We describe a method for leukocyte sorting by a microarray of anti-cluster-of-differentiation (anti-CD) antibodies and for preparation of the bound cells for morphological or cytochemical examination. The procedure results in a "sorted" smear with cells positive for certain surface antigens localised in predefined areas. The morphology and cytochemistry of the microarray-captured normal and neoplastic peripheral blood mononuclear cells are identical to the same characteristics in a smear. The microarray permits to determine the proportions of cells positive for the CD antigens on the microarray panel with high correlation with flow cytometry. Using the anti-CD microarray we show that normal granular lymphocytes and lymphocytes with radial segmentation of the nuclei are positive for CD3, CD8, CD16 or CD56 but not for CD4 or CD19. We also show that the described technique permits to obtain a pure leukemic cell population or to separate two leukemic cell populations on different antibody spots and to study their morphology or cytochemistry directly on the microarray. In cases of leukemias/lymphomas when circulating neoplastic cells are morphologically distinct, preliminary diagnosis can be suggested from full analysis of cell morphology, cytochemistry and their binding pattern on the microarray.

  19. EST and microarray analysis of horn development in Onthophagus beetles

    Directory of Open Access Journals (Sweden)

    Tang Zuojian

    2009-10-01

    Full Text Available Abstract Background The origin of novel traits and their subsequent diversification represent central themes in evo-devo and evolutionary ecology. Here we explore the genetic and genomic basis of a class of traits that is both novel and highly diverse, in a group of organisms that is ecologically complex and experimentally tractable: horned beetles. Results We developed two high quality, normalized cDNA libraries for larval and pupal Onthophagus taurus and sequenced 3,488 ESTs that assembled into 451 contigs and 2,330 singletons. We present the annotation and a comparative analysis of the conservation of the sequences. Microarrays developed from the combined libraries were then used to contrast the transcriptome of developing primordia of head horns, prothoracic horns, and legs. Our experiments identify a first comprehensive list of candidate genes for the evolution and diversification of beetle horns. We find that developing horns and legs show many similarities as well as important differences in their transcription profiles, suggesting that the origin of horns was mediated partly, but not entirely, by the recruitment of genes involved in the formation of more traditional appendages such as legs. Furthermore, we find that horns developing from the head and prothorax differ in their transcription profiles to a degree that suggests that head and prothoracic horns are not serial homologs, but instead may have evolved independently from each other. Conclusion We have laid the foundation for a systematic analysis of the genetic basis of horned beetle development and diversification with the potential to contribute significantly to several major frontiers in evolutionary developmental biology.

  20. Discovering biological progression underlying microarray samples.

    Directory of Open Access Journals (Sweden)

    Peng Qiu

    2011-04-01

    Full Text Available In biological systems that undergo processes such as differentiation, a clear concept of progression exists. We present a novel computational approach, called Sample Progression Discovery (SPD, to discover patterns of biological progression underlying microarray gene expression data. SPD assumes that individual samples of a microarray dataset are related by an unknown biological process (i.e., differentiation, development, cell cycle, disease progression, and that each sample represents one unknown point along the progression of that process. SPD aims to organize the samples in a manner that reveals the underlying progression and to simultaneously identify subsets of genes that are responsible for that progression. We demonstrate the performance of SPD on a variety of microarray datasets that were generated by sampling a biological process at different points along its progression, without providing SPD any information of the underlying process. When applied to a cell cycle time series microarray dataset, SPD was not provided any prior knowledge of samples' time order or of which genes are cell-cycle regulated, yet SPD recovered the correct time order and identified many genes that have been associated with the cell cycle. When applied to B-cell differentiation data, SPD recovered the correct order of stages of normal B-cell differentiation and the linkage between preB-ALL tumor cells with their cell origin preB. When applied to mouse embryonic stem cell differentiation data, SPD uncovered a landscape of ESC differentiation into various lineages and genes that represent both generic and lineage specific processes. When applied to a prostate cancer microarray dataset, SPD identified gene modules that reflect a progression consistent with disease stages. SPD may be best viewed as a novel tool for synthesizing biological hypotheses because it provides a likely biological progression underlying a microarray dataset and, perhaps more importantly, the

  1. [Research on the relevance between the virulent genes differential expression and pathogenecity of Leptospira with microarray].

    Science.gov (United States)

    Yu, De-li; Bao, Lang

    2015-01-01

    To find the change of virulent gene expression and to analyze the relevance between the virulent change and the gene expression. Grouped guinea pigs were inoculated with 1 mL Leptospira cultured in vivo, Leptospira cultured in vitro and the Leptospira culture medium through abdominal subcutaneous respectively. The survival rate, body mass and temperature change of guinea pigs in different groups were measured within 15 d after the inoculation, then the survived guinea pigs were scarified, and the organ coefficient was also measured to know the virulence of Leptospira cultured in different environment. The amplified gene segments from Leptospira were used as probes and wrote the microarray. The total RNA was extracted from Leptospira standard strain cultured in culture medium and guinea pigs. After reverse transcription to cDNA, they were labeled with Cy3 and Cy5 respectively. Labeled cDNA was mixed and hybridized with the microarray. The hybridized mircroarray was scanned and analysed. The survival rate of inoculated guinea pig was different from group to group (in vivo group: 0%; in vitro group: 88.9%; culture medium group: 100%). The guinea pigs in vivo group had a higher temperature (PLeptospira: LA1027, LA1029, LA4004, LA3050, LA3540, LA0327, LA0378, LA1650, LA3937, LA2089, LA2144, LA3576, LA0011 and gene of Loa22 were up regulation after continuously cultured in guinea pigs. The pathogenic ability of Leptospira cultured in different environment is different and the gene expression of Leptospira is different between in vivo and in vitro as well. The understanding of the meaning of this change might help to know the pathogenecity of Leptospira.

  2. The use of microarrays in microbial ecology

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, G.L.; He, Z.; DeSantis, T.Z.; Brodie, E.L.; Zhou, J.

    2009-09-15

    Microarrays have proven to be a useful and high-throughput method to provide targeted DNA sequence information for up to many thousands of specific genetic regions in a single test. A microarray consists of multiple DNA oligonucleotide probes that, under high stringency conditions, hybridize only to specific complementary nucleic acid sequences (targets). A fluorescent signal indicates the presence and, in many cases, the abundance of genetic regions of interest. In this chapter we will look at how microarrays are used in microbial ecology, especially with the recent increase in microbial community DNA sequence data. Of particular interest to microbial ecologists, phylogenetic microarrays are used for the analysis of phylotypes in a community and functional gene arrays are used for the analysis of functional genes, and, by inference, phylotypes in environmental samples. A phylogenetic microarray that has been developed by the Andersen laboratory, the PhyloChip, will be discussed as an example of a microarray that targets the known diversity within the 16S rRNA gene to determine microbial community composition. Using multiple, confirmatory probes to increase the confidence of detection and a mismatch probe for every perfect match probe to minimize the effect of cross-hybridization by non-target regions, the PhyloChip is able to simultaneously identify any of thousands of taxa present in an environmental sample. The PhyloChip is shown to reveal greater diversity within a community than rRNA gene sequencing due to the placement of the entire gene product on the microarray compared with the analysis of up to thousands of individual molecules by traditional sequencing methods. A functional gene array that has been developed by the Zhou laboratory, the GeoChip, will be discussed as an example of a microarray that dynamically identifies functional activities of multiple members within a community. The recent version of GeoChip contains more than 24,000 50mer

  3. Molecular cloning of growth hormone encoding cDNA of Indian ...

    Indian Academy of Sciences (India)

    A modified rapid amplification of cDNA ends (RACE) strategy has been developed for cloning highly conserved cDNA sequences. Using this modified method, the growth hormone (GH) encoding cDNA sequences of Labeo rohita, Cirrhina mrigala and Catla catla have been cloned, characterized and overexpressed in ...

  4. cDNA cloning and characterization of a mannose-binding lectin from ...

    Indian Academy of Sciences (India)

    Using RNA extracted from Zingiber officinale rhizomes and primers designed according to the conservative regions of monocot mannose-binding lectins, the full-length cDNA of Z. officinale agglutinin (ZOA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zoa was 746 bp and contained a ...

  5. Isolation and characterization of a Coffea canephora ERF-like c-DNA

    African Journals Online (AJOL)

    A cDNA corresponding to an ERF gene has been isolated from a Coffea canephora fruit cDNA library. The cDNA was 1,317 nucleotides long and has an open reading frame of 987 bp. The predicted polypeptide showed a great similitude with equivalent proteins from others plant species. The binding domain shows 98.3% ...

  6. Molecular cloning of growth hormone encoding cDNA of Indian

    Indian Academy of Sciences (India)

    A modified rapid amplification of cDNA ends (RACE) strategy has been developed for cloning highly conserved cDNA sequences. Using this modified method, the growth hormone (GH) encoding cDNA sequences of Labeo rohita, Cirrhina mrigala and Catla catla have been cloned, characterized and overexpressed in ...

  7. cDNA cloning and characterization of a mannose-binding lectin

    Indian Academy of Sciences (India)

    Using RNA extracted from Zingiber officinale rhizomes and primers designed according to the conservative regions of monocot mannose-binding lectins, the full-length cDNA of Z. officinale agglutinin (ZOA) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of zoa was 746 bp and contained a ...

  8. cDNA library information - Dicty_cDB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available (C) 5) sexually fusion-competent KAX3 cells (Gamete phase) (F) cDNA library construction method How to const...dir) 2) Full-length cDNA libraries (oligocapped method)(fl) 3) Gamete-specific subtraction library (sub) cDNA library construction

  9. [CDNA cloning of human leptin and its expression].

    Science.gov (United States)

    Jia, Zhen-Yu; Fu, Xiao-Min; Jin, Ai-Hua; Cao, Jiang

    2003-07-01

    To clone cDNA of human leptin gene and obtain leptin protein for future study on leptin binding proteins. The cDNA of human leptin with 6 x his-tag was cloned by over-hang extension PCR protocol using human genomic DNA as template, and subcloned into in vitro expression vector pIVEX2.3MCS, and the fusion protein was expressed in vitro by Rapid Translation System (RTS) (RTS500 cycle primer Kit and RTS500 ProteoMaster of Roche company). The apparent molecular weight(19.46 kD) and the immuno-specificity of the fusion protein were confirmed by SDS-PAGE and Western blot, and the expressed fusion protein stayed mainly in the supernatant of the reaction mixture in soluble form. This work provides us solid basis for further study on new leptin-associated proteins.

  10. Construction of cDNA library of Pyrocystis lunula (Pyrophyta)

    Science.gov (United States)

    Sui, Zhenghong; Kowallik, Klaus V.

    2004-10-01

    Complementary DNA library of a dinoflagellate Pyrocystis lunula was constructed for the purpose of expression sequence tags analysis. The RNA isolated from this alga was about 20µgg-1 net cells, and the band intensity ratio of 28S/18 S in electrophoresis pattern was nearly 1 to 1. Different cDNA/vector molar ratios were exploited in the ligating reaction to be optimized. The clones produced by cDNA/vector molar ratio of 3.75 to 1 were desirable, most of whose inserts were longer than 300 bp. The recombinants insert length of the unfractionation cDNA library was largely shorter than 500 bp. However, in the fractionation library made from high molecule weight cDNA parts, over seventy percent of the recombinants contained inserts longer than 1 kb, some of which were even longer than 3 kb. Operating concerns were discussed at the end.

  11. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  12. Construction of cDNA libraries in vaccinia virus.

    Science.gov (United States)

    Smith, Ernest S; Shi, Shuying; Zauderer, Maurice

    2004-01-01

    Poxvirus expression vectors have gained widespread use for expression of foreign proteins and as delivery vehicles for vaccine antigens. We have developed a novel method using the poxvirus as a library vector for functional selection of specific cDNA. Poxviruses have several unique and useful properties as a library vector. Most importantly, because poxviruses are packaged into fully infectious particles in the cell cytoplasm, specific recombinants can be readily recovered even from a very small number of selected cells. Moreover, in contrast to libraries constructed in retrovirus or plasmid-based vectors, recombinant vaccinia virus can be efficiently recovered even from cells that have been induced to undergo apoptosis or cessation of cell growth. In the past, the major obstacle in this application to poxviruses has been the low frequency with which recombinants can be generated. The most commonly used method to construct recombinant poxvirus is homologous recombination. The frequency of recombinants derived in this manner is of the order of 0.1%, sufficient to recover a recombinant of a purified DNA clone in a transfer plasmid, but far too low to permit construction of a representative cDNA library. We have developed a method that generates nearly 100% recombinant vaccinia viruses at good titer. We have termed this method trimolecular recombination. cDNA libraries of as many as 107 or more independent viral recombinants can be constructed by trimolecular recombination. For the first time, large, diverse, and representative cDNA libraries can be screened in a vaccinia virus-based expression vector.

  13. cDNA cloning, structural analysis, SNP detection and tissue ...

    Indian Academy of Sciences (India)

    THOMAS NAICY

    E-mail: naicy@kvasu.ac.in. and conception rate ... transformed into DH5α strain of Escherichia coli and the clones harbouring ... Primer pairs for caprine IGF1 and GAPDH were designed using Primer3 software (table 1). RTq-PCR was conducted in a 25 μL reaction volume containing 50 ng of cDNA and 2× Max- ima SYBR ...

  14. Microarray Я US: a user-friendly graphical interface to Bioconductor tools that enables accurate microarray data analysis and expedites comprehensive functional analysis of microarray results

    Directory of Open Access Journals (Sweden)

    Dai Yilin

    2012-06-01

    Full Text Available Abstract Background Microarray data analysis presents a significant challenge to researchers who are unable to use the powerful Bioconductor and its numerous tools due to their lack of knowledge of R language. Among the few existing software programs that offer a graphic user interface to Bioconductor packages, none have implemented a comprehensive strategy to address the accuracy and reliability issue of microarray data analysis due to the well known probe design problems associated with many widely used microarray chips. There is also a lack of tools that would expedite the functional analysis of microarray results. Findings We present Microarray Я US, an R-based graphical user interface that implements over a dozen popular Bioconductor packages to offer researchers a streamlined workflow for routine differential microarray expression data analysis without the need to learn R language. In order to enable a more accurate analysis and interpretation of microarray data, we incorporated the latest custom probe re-definition and re-annotation for Affymetrix and Illumina chips. A versatile microarray results output utility tool was also implemented for easy and fast generation of input files for over 20 of the most widely used functional analysis software programs. Conclusion Coupled with a well-designed user interface, Microarray Я US leverages cutting edge Bioconductor packages for researchers with no knowledge in R language. It also enables a more reliable and accurate microarray data analysis and expedites downstream functional analysis of microarray results.

  15. [Construction of subtractive cDNA library of apoptosis-related genes in NB4 cells treated by arsenic trioxide].

    Science.gov (United States)

    Di, Chunhong; Gu, Shaohua; Tan, Xiaohua; Xian, Lingling; Wu, Qihan; Yang, Lei

    2009-02-01

    Construct the gene library of apoptosis related genes in acute promyelocytic leukemia (APL) cell line NB4 cells treated by arsenic trioxide to clarify the apoptotic mechanism of NB4 cells. APL cell line NB4 cells treated with or without arsenic trioxide for 24 hours. Total RNA was extracted and suppress subtractive hybridization (SSH) was conducted according to the manual. With the cDNA of the apoptosis cells as the tester and that of control cells as the driver, forward and reverse hybridization was performed. Differentially expressed genes were linked with pGEM-Teasy cloning vector and transformed into E. coli DH5alpha. The positive clones were screened by blue and white spot. PCR were used to amplify these genes. The subtractive cDNA libraries related with apoptosis of NB4 cells were successfully constructed. The constructed subtractive libraries are suitable for further study on the functional genes associated with apoptosis ofNB4 cells induced by arsenic trioxide.

  16. CDNA encoding a polypeptide including a hevein sequence

    Science.gov (United States)

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  17. cDNA library generation from ribonucleoprotein particles.

    Science.gov (United States)

    Rederstorff, Mathieu; Hüttenhofer, Alexander

    2011-02-01

    Most, if not all, known noncoding RNAs (ncRNAs) are associated with RNA binding proteins, thus forming ribonucleoprotein particles or RNPs. Here we describe a protocol for the generation of a specialized cDNA library from RNPs, thereby increasing the proportion of functional ncRNA species in the library. To that end, cellular extracts are fractionated on 10-30% glycerol gradients. Subsequently, RNP-derived ncRNAs are isolated and 3'-tailed by cytidine triphosphate and poly(A) polymerase; this is followed by 5' adapter ligation by T4 RNA ligase. Reverse transcription of ncRNAs into cDNAs is carried out with an oligo-d(G) anchor primer. The generated cDNA libraries are subsequently submitted to high-throughput sequencing. This RNP selection procedure increases the probability of the presence of biologically relevant ncRNA species in the library compared with libraries generation methods that use size-selected, protein-devoid ncRNAs. The protocol enables the generation of deep-sequencing-compatible cDNA libraries that code for functional ncRNAs within 1 week.

  18. cDNA encoding a polypeptide including a hevein sequence

    Energy Technology Data Exchange (ETDEWEB)

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  19. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  20. Bacterial species determination from DNA-DNA hybridization by using genome fragments and DNA microarrays.

    Science.gov (United States)

    Cho, J C; Tiedje, J M

    2001-08-01

    Whole genomic DNA-DNA hybridization has been a cornerstone of bacterial species determination but is not widely used because it is not easily implemented. We have developed a method based on random genome fragments and DNA microarray technology that overcomes the disadvantages of whole-genome DNA-DNA hybridization. Reference genomes of four fluorescent Pseudomonas species were fragmented, and 60 to 96 genome fragments of approximately 1 kb from each strain were spotted on microarrays. Genomes from 12 well-characterized fluorescent Pseudomonas strains were labeled with Cy dyes and hybridized to the arrays. Cluster analysis of the hybridization profiles revealed taxonomic relationships between bacterial strains tested at species to strain level resolution, suggesting that this approach is useful for the identification of bacteria as well as determining the genetic distance among bacteria. Since arrays can contain thousands of DNA spots, a single array has the potential for broad identification capacity. In addition, the method does not require laborious cross-hybridizations and can provide an open database of hybridization profiles, avoiding the limitations of traditional DNA-DNA hybridization.

  1. Image Processing of Porous Silicon Microarray in Refractive Index Change Detection

    Directory of Open Access Journals (Sweden)

    Zhiqing Guo

    2017-06-01

    Full Text Available A new method for extracting the dots is proposed by the reflected light image of porous silicon (PSi microarray utilization in this paper. The method consists of three parts: pretreatment, tilt correction and spot segmentation. First, based on the characteristics of different components in HSV (Hue, Saturation, Value space, a special pretreatment is proposed for the reflected light image to obtain the contour edges of the array cells in the image. Second, through the geometric relationship of the target object between the initial external rectangle and the minimum bounding rectangle (MBR, a new tilt correction algorithm based on the MBR is proposed to adjust the image. Third, based on the specific requirements of the reflected light image segmentation, the array cells are segmented into dots as large as possible and the distance between the dots is equal in the corrected image. Experimental results show that the pretreatment part of this method can effectively avoid the influence of complex background and complete the binarization processing of the image. The tilt correction algorithm has a shorter computation time, which makes it highly suitable for tilt correction of reflected light images. The segmentation algorithm makes the dots in a regular arrangement, excludes the edges and the bright spots. This method could be utilized in the fast, accurate and automatic dots extraction of the PSi microarray reflected light image.

  2. Image Processing of Porous Silicon Microarray in Refractive Index Change Detection.

    Science.gov (United States)

    Guo, Zhiqing; Jia, Zhenhong; Yang, Jie; Kasabov, Nikola; Li, Chuanxi

    2017-06-08

    A new method for extracting the dots is proposed by the reflected light image of porous silicon (PSi) microarray utilization in this paper. The method consists of three parts: pretreatment, tilt correction and spot segmentation. First, based on the characteristics of different components in HSV (Hue, Saturation, Value) space, a special pretreatment is proposed for the reflected light image to obtain the contour edges of the array cells in the image. Second, through the geometric relationship of the target object between the initial external rectangle and the minimum bounding rectangle (MBR), a new tilt correction algorithm based on the MBR is proposed to adjust the image. Third, based on the specific requirements of the reflected light image segmentation, the array cells are segmented into dots as large as possible and the distance between the dots is equal in the corrected image. Experimental results show that the pretreatment part of this method can effectively avoid the influence of complex background and complete the binarization processing of the image. The tilt correction algorithm has a shorter computation time, which makes it highly suitable for tilt correction of reflected light images. The segmentation algorithm makes the dots in a regular arrangement, excludes the edges and the bright spots. This method could be utilized in the fast, accurate and automatic dots extraction of the PSi microarray reflected light image.

  3. Cellular neural networks, the Navier-Stokes equation, and microarray image reconstruction.

    Science.gov (United States)

    Zineddin, Bachar; Wang, Zidong; Liu, Xiaohui

    2011-11-01

    Although the last decade has witnessed a great deal of improvements achieved for the microarray technology, many major developments in all the main stages of this technology, including image processing, are still needed. Some hardware implementations of microarray image processing have been proposed in the literature and proved to be promising alternatives to the currently available software systems. However, the main drawback of those proposed approaches is the unsuitable addressing of the quantification of the gene spot in a realistic way without any assumption about the image surface. Our aim in this paper is to present a new image-reconstruction algorithm using the cellular neural network that solves the Navier-Stokes equation. This algorithm offers a robust method for estimating the background signal within the gene-spot region. The MATCNN toolbox for Matlab is used to test the proposed method. Quantitative comparisons are carried out, i.e., in terms of objective criteria, between our approach and some other available methods. It is shown that the proposed algorithm gives highly accurate and realistic measurements in a fully automated manner within a remarkably efficient time.

  4. Visible DNA microarray system as an adjunctive molecular test in the identification of pathogenic fungi directly from a blood culture bottle.

    Science.gov (United States)

    Sturaro, Lais Lovison; Gonoi, Tohru; Busso-Lopes, Ariane Fidelis; Tararam, Cibele Aparecida; Levy, Carlos Emilio; Lyra, Luzia; Trabasso, Plinio; Schreiber, Angélica Zaninelli; Kamei, Katsuhiko; Moretti, Maria Luiza

    2018-03-07

    A DNA microarray platform, based on the nucleotide sequences of the internal transcribed spacer regions (ITS1, ITS2) of the rRNA gene, was developed to identify 32 fungal pathogens at the species level. The probe sequences were spotted onto polycarbonate slides with a mini-microarray printer, and after the hybridization, the results were visible with the naked eye. The performance of the microarray platform was evaluated against the commercial automated systems (Vitek ® 2 and BD Phoenix™ systems) and DNA sequencing (gold standard). A total of 461 blood culture bottles were tested: 127 positive for fungi, 302 positive for bacteria, and 32 tested negative. Once the microorganisms were identified by automated systems, fungal DNA was extracted directly from the blood culture bottles. The DNA products were tested using the microarray platform, and DNA sequencing was performed. The results of the microarray and DNA sequencing were concordant in 96.7% of cases, and the results from the automated systems and DNA sequencing were concordant in 98.4%. Of all the nucleotide sequences contained in the microarray platform, the microarray failed to identify four fungal isolates (one Candida parapsilosis , two Candida tropicalis, and one Cryptococcus neoformans ). Of note, the microarray detected Candida krusei DNA in two blood cultures from the same patient, whereas the automated system was only positive for Enterococcus faecium. Our microarray system provided reliable and fast fungal identification compared to DNA sequencing and the automated systems. The simplicity of reading the results by the naked eye made this DNA platform a suitable method for fungal molecular diagnosis. Copyright © 2018 American Society for Microbiology.

  5. Biological microarray interpretation : The rules of engagement

    NARCIS (Netherlands)

    Breitling, Rainer

    2006-01-01

    Gene expression microarrays are now established as a standard tool in biological and biochemical laboratories. Interpreting the masses of data generated by this technology poses a number of unusual new challenges. Over the past few years a consensus has begun to emerge concerning the most important

  6. Single-species microarrays and comparative transcriptomics.

    Directory of Open Access Journals (Sweden)

    Frédéric J J Chain

    Full Text Available BACKGROUND: Prefabricated expression microarrays are currently available for only a few species but methods have been proposed to extend their application to comparisons between divergent genomes. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrate that the hybridization intensity of genomic DNA is a poor basis on which to select unbiased probes on Affymetrix expression arrays for studies of comparative transcriptomics, and that doing so produces spurious results. We used the Affymetrix Xenopus laevis microarray to evaluate expression divergence between X. laevis, X. borealis, and their F1 hybrids. When data are analyzed with probes that interrogate only sequences with confirmed identity in both species, we recover results that differ substantially analyses that use genomic DNA hybridizations to select probes. CONCLUSIONS/SIGNIFICANCE: Our findings have implications for the experimental design of comparative expression studies that use single-species microarrays, and for our understanding of divergent expression in hybrid clawed frogs. These findings also highlight important limitations of single-species microarrays for studies of comparative transcriptomics of polyploid species.

  7. Microarray technology: a promising tool in nutrigenomics.

    Science.gov (United States)

    Masotti, Andrea; Da Sacco, Letizia; Bottazzo, Gian Franco; Alisi, Anna

    2010-08-01

    Microarray technology is a powerful tool for the global evaluation of gene expression profiles in tissues and for understanding many of the factors controlling the regulation of gene transcription. This technique not only provides a considerable amount of information on markers and predictive factors that may potentially characterize a specific clinical picture, but also promises new applications for therapy. One of the most recent applications of microarrays concerns nutritional genomics. Nutritional genomics, known as nutrigenomics, aims to identify and understand mechanisms of molecular interaction between nutrients and/or other dietary bioactive compounds and the genome. Actually, many nutrigenomic studies utilize new approaches such as microarrays, genomics, and bioinformatics to understand how nutrients influence gene expression. The coupling of these new technologies with nutrigenomics promises to lead to improvements in diet and health. In fact, it may provide new information which can be used to ameliorate dietary regimens and to discover novel natural agents for the treatment of important diseases such as diabetes and cancer. This critical review gives an overview of the clinical relevance of a nutritional approach to several important diseases, and proposes the use of microarray for nutrigenomic studies.

  8. Comparing transformation methods for DNA microarray data

    NARCIS (Netherlands)

    Thygesen, Helene H.; Zwinderman, Aeilko H.

    2004-01-01

    Background: When DNA microarray data are used for gene clustering, genotype/phenotype correlation studies, or tissue classification the signal intensities are usually transformed and normalized in several steps in order to improve comparability and signal/noise ratio. These steps may include

  9. Shrinkage covariance matrix approach for microarray data

    Science.gov (United States)

    Karjanto, Suryaefiza; Aripin, Rasimah

    2013-04-01

    Microarray technology was developed for the purpose of monitoring the expression levels of thousands of genes. A microarray data set typically consists of tens of thousands of genes (variables) from just dozens of samples due to various constraints including the high cost of producing microarray chips. As a result, the widely used standard covariance estimator is not appropriate for this purpose. One such technique is the Hotelling's T2 statistic which is a multivariate test statistic for comparing means between two groups. It requires that the number of observations (n) exceeds the number of genes (p) in the set but in microarray studies it is common that n Hotelling's T2 statistic with the shrinkage approach is proposed to estimate the covariance matrix for testing differential gene expression. The performance of this approach is then compared with other commonly used multivariate tests using a widely analysed diabetes data set as illustrations. The results across the methods are consistent, implying that this approach provides an alternative to existing techniques.

  10. Evaluating different methods of microarray data normalization

    Directory of Open Access Journals (Sweden)

    Ferreira Carlos

    2006-10-01

    Full Text Available Abstract Background With the development of DNA hybridization microarray technologies, nowadays it is possible to simultaneously assess the expression levels of thousands to tens of thousands of genes. Quantitative comparison of microarrays uncovers distinct patterns of gene expression, which define different cellular phenotypes or cellular responses to drugs. Due to technical biases, normalization of the intensity levels is a pre-requisite to performing further statistical analyses. Therefore, choosing a suitable approach for normalization can be critical, deserving judicious consideration. Results Here, we considered three commonly used normalization approaches, namely: Loess, Splines and Wavelets, and two non-parametric regression methods, which have yet to be used for normalization, namely, the Kernel smoothing and Support Vector Regression. The results obtained were compared using artificial microarray data and benchmark studies. The results indicate that the Support Vector Regression is the most robust to outliers and that Kernel is the worst normalization technique, while no practical differences were observed between Loess, Splines and Wavelets. Conclusion In face of our results, the Support Vector Regression is favored for microarray normalization due to its superiority when compared to the other methods for its robustness in estimating the normalization curve.

  11. Ecologically relevant stress resistance: from microarrays and ...

    Indian Academy of Sciences (India)

    2004-10-15

    Oct 15, 2004 ... Home; Journals; Journal of Biosciences; Volume 29; Issue 4. Ecologically relevant stress resistance: from microarrays and quantitative trait loci to candidate genes – A research plan and preliminary results using Drosophila as a model organism and climatic and genetic stress as model stresses.

  12. Design of a covalently bonded glycosphingolipid microarray

    DEFF Research Database (Denmark)

    Arigi, Emma; Blixt, Klas Ola; Buschard, Karsten

    2012-01-01

    Glycosphingolipids (GSLs) are well known ubiquitous constituents of all eukaryotic cell membranes, yet their normal biological functions are not fully understood. As with other glycoconjugates and saccharides, solid phase display on microarrays potentially provides an effective platform for in vi......Glycosphingolipids (GSLs) are well known ubiquitous constituents of all eukaryotic cell membranes, yet their normal biological functions are not fully understood. As with other glycoconjugates and saccharides, solid phase display on microarrays potentially provides an effective platform......, the major classes of plant and fungal GSLs. In this work, a prototype "universal" GSL-based covalent microarray has been designed, and preliminary evaluation of its potential utility in assaying protein-GSL binding interactions investigated. An essential step in development involved the enzymatic release......-mercaptoethylamine, was also tested. Underivatized or linker-derivatized lyso-GSL were then immobilized on N-hydroxysuccinimide- or epoxide-activated glass microarray slides and probed with carbohydrate binding proteins of known or partially known specificities (i.e., cholera toxin B-chain; peanut agglutinin...

  13. Superhydrophilic-Superhydrophobic Patterned Surfaces as High-Density Cell Microarrays: Optimization of Reverse Transfection.

    Science.gov (United States)

    Ueda, Erica; Feng, Wenqian; Levkin, Pavel A

    2016-10-01

    High-density microarrays can screen thousands of genetic and chemical probes at once in a miniaturized and parallelized manner, and thus are a cost-effective alternative to microwell plates. Here, high-density cell microarrays are fabricated by creating superhydrophilic-superhydrophobic micropatterns in thin, nanoporous polymer substrates such that the superhydrophobic barriers confine both aqueous solutions and adherent cells within each superhydrophilic microspot. The superhydrophobic barriers confine and prevent the mixing of larger droplet volumes, and also control the spreading of droplets independent of the volume, minimizing the variability that arises due to different liquid and surface properties. Using a novel liposomal transfection reagent, ScreenFect A, the method of reverse cell transfection is optimized on the patterned substrates and several factors that affect transfection efficiency and cytotoxicity are identified. Higher levels of transfection are achieved on HOOC- versus NH 2 -functionalized superhydrophilic spots, as well as when gelatin and fibronectin are added to the transfection mixture, while minimizing the amount of transfection reagent improves cell viability. Almost no diffusion of the printed transfection mixtures to the neighboring microspots is detected. Thus, superhydrophilic-superhydrophobic patterned surfaces can be used as cell microarrays and for optimizing reverse cell transfection conditions before performing further cell screenings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A method of microarray data storage using array data type.

    Science.gov (United States)

    Tsoi, Lam C; Zheng, W Jim

    2007-04-01

    A well-designed microarray database can provide valuable information on gene expression levels. However, designing an efficient microarray database with minimum space usage is not an easy task since designers need to integrate the microarray data with the information of genes, probe annotation, and the descriptions of each microarray experiment. Developing better methods to store microarray data can greatly improve the efficiency and usefulness of such data. A new schema is proposed to store microarray data by using array data type in an object-relational database management system--PostgreSQL. The implemented database can store all the microarray data from the same chip in an array data structure. The variable-length array data type in PostgreSQL can store microarray data from same chip. The implementation of our schema can help to increase the data retrieval and space efficiency.

  15. Microarray Analysis of Space-flown Murine Thymus Tissue

    Data.gov (United States)

    National Aeronautics and Space Administration — Microarray Analysis of Space-flown Murine Thymus Tissue Reveals Changes in Gene Expression Regulating Stress and Glucocorticoid Receptors. We used microarrays to...

  16. Identifying Fishes through DNA Barcodes and Microarrays.

    Science.gov (United States)

    Kochzius, Marc; Seidel, Christian; Antoniou, Aglaia; Botla, Sandeep Kumar; Campo, Daniel; Cariani, Alessia; Vazquez, Eva Garcia; Hauschild, Janet; Hervet, Caroline; Hjörleifsdottir, Sigridur; Hreggvidsson, Gudmundur; Kappel, Kristina; Landi, Monica; Magoulas, Antonios; Marteinsson, Viggo; Nölte, Manfred; Planes, Serge; Tinti, Fausto; Turan, Cemal; Venugopal, Moleyur N; Weber, Hannes; Blohm, Dietmar

    2010-09-07

    International fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection. This study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S), cytochrome b (cyt b), and cytochrome oxidase subunit I (COI) for the identification of 50 European marine fish species by combining techniques of "DNA barcoding" and microarrays. In a DNA barcoding approach, neighbour Joining (NJ) phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the "position of label" effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (>90%) renders the DNA barcoding marker as rather unsuitable for this high-throughput technology. Based on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products.

  17. Identifying Fishes through DNA Barcodes and Microarrays.

    Directory of Open Access Journals (Sweden)

    Marc Kochzius

    Full Text Available BACKGROUND: International fish trade reached an import value of 62.8 billion Euro in 2006, of which 44.6% are covered by the European Union. Species identification is a key problem throughout the life cycle of fishes: from eggs and larvae to adults in fisheries research and control, as well as processed fish products in consumer protection. METHODOLOGY/PRINCIPAL FINDINGS: This study aims to evaluate the applicability of the three mitochondrial genes 16S rRNA (16S, cytochrome b (cyt b, and cytochrome oxidase subunit I (COI for the identification of 50 European marine fish species by combining techniques of "DNA barcoding" and microarrays. In a DNA barcoding approach, neighbour Joining (NJ phylogenetic trees of 369 16S, 212 cyt b, and 447 COI sequences indicated that cyt b and COI are suitable for unambiguous identification, whereas 16S failed to discriminate closely related flatfish and gurnard species. In course of probe design for DNA microarray development, each of the markers yielded a high number of potentially species-specific probes in silico, although many of them were rejected based on microarray hybridisation experiments. None of the markers provided probes to discriminate the sibling flatfish and gurnard species. However, since 16S-probes were less negatively influenced by the "position of label" effect and showed the lowest rejection rate and the highest mean signal intensity, 16S is more suitable for DNA microarray probe design than cty b and COI. The large portion of rejected COI-probes after hybridisation experiments (>90% renders the DNA barcoding marker as rather unsuitable for this high-throughput technology. CONCLUSIONS/SIGNIFICANCE: Based on these data, a DNA microarray containing 64 functional oligonucleotide probes for the identification of 30 out of the 50 fish species investigated was developed. It represents the next step towards an automated and easy-to-handle method to identify fish, ichthyoplankton, and fish products.

  18. Facilitating functional annotation of chicken microarray data

    Directory of Open Access Journals (Sweden)

    Gresham Cathy R

    2009-10-01

    Full Text Available Abstract Background Modeling results from chicken microarray studies is challenging for researchers due to little functional annotation associated with these arrays. The Affymetrix GenChip chicken genome array, one of the biggest arrays that serve as a key research tool for the study of chicken functional genomics, is among the few arrays that link gene products to Gene Ontology (GO. However the GO annotation data presented by Affymetrix is incomplete, for example, they do not show references linked to manually annotated functions. In addition, there is no tool that facilitates microarray researchers to directly retrieve functional annotations for their datasets from the annotated arrays. This costs researchers amount of time in searching multiple GO databases for functional information. Results We have improved the breadth of functional annotations of the gene products associated with probesets on the Affymetrix chicken genome array by 45% and the quality of annotation by 14%. We have also identified the most significant diseases and disorders, different types of genes, and known drug targets represented on Affymetrix chicken genome array. To facilitate functional annotation of other arrays and microarray experimental datasets we developed an Array GO Mapper (AGOM tool to help researchers to quickly retrieve corresponding functional information for their dataset. Conclusion Results from this study will directly facilitate annotation of other chicken arrays and microarray experimental datasets. Researchers will be able to quickly model their microarray dataset into more reliable biological functional information by using AGOM tool. The disease, disorders, gene types and drug targets revealed in the study will allow researchers to learn more about how genes function in complex biological systems and may lead to new drug discovery and development of therapies. The GO annotation data generated will be available for public use via AgBase website and

  19. Development of a high-throughput microfluidic integrated microarray for the detection of chimeric bioweapons.

    Energy Technology Data Exchange (ETDEWEB)

    Sheppod, Timothy; Satterfield, Brent; Hukari, Kyle W.; West, Jason A. A.; Hux, Gary A.

    2006-10-01

    The advancement of DNA cloning has significantly augmented the potential threat of a focused bioweapon assault, such as a terrorist attack. With current DNA cloning techniques, toxin genes from the most dangerous (but environmentally labile) bacterial or viral organism can now be selected and inserted into robust organism to produce an infinite number of deadly chimeric bioweapons. In order to neutralize such a threat, accurate detection of the expressed toxin genes, rather than classification on strain or genealogical decent of these organisms, is critical. The development of a high-throughput microarray approach will enable the detection of unknowns chimeric bioweapons. The development of a high-throughput microarray approach will enable the detection of unknown bioweapons. We have developed a unique microfluidic approach to capture and concentrate these threat genes (mRNA's) upto a 30 fold concentration. These captured oligonucleotides can then be used to synthesize in situ oligonucleotide copies (cDNA probes) of the captured genes. An integrated microfluidic architecture will enable us to control flows of reagents, perform clean-up steps and finally elute nanoliter volumes of synthesized oligonucleotides probes. The integrated approach has enabled a process where chimeric or conventional bioweapons can rapidly be identified based on their toxic function, rather than being restricted to information that may not identify the critical nature of the threat.

  20. arrayCGHbase: an analysis platform for comparative genomic hybridization microarrays

    Directory of Open Access Journals (Sweden)

    Moreau Yves

    2005-05-01

    Full Text Available Abstract Background The availability of the human genome sequence as well as the large number of physically accessible oligonucleotides, cDNA, and BAC clones across the entire genome has triggered and accelerated the use of several platforms for analysis of DNA copy number changes, amongst others microarray comparative genomic hybridization (arrayCGH. One of the challenges inherent to this new technology is the management and analysis of large numbers of data points generated in each individual experiment. Results We have developed arrayCGHbase, a comprehensive analysis platform for arrayCGH experiments consisting of a MIAME (Minimal Information About a Microarray Experiment supportive database using MySQL underlying a data mining web tool, to store, analyze, interpret, compare, and visualize arrayCGH results in a uniform and user-friendly format. Following its flexible design, arrayCGHbase is compatible with all existing and forthcoming arrayCGH platforms. Data can be exported in a multitude of formats, including BED files to map copy number information on the genome using the Ensembl or UCSC genome browser. Conclusion ArrayCGHbase is a web based and platform independent arrayCGH data analysis tool, that allows users to access the analysis suite through the internet or a local intranet after installation on a private server. ArrayCGHbase is available at http://medgen.ugent.be/arrayCGHbase/.

  1. Use of signal thresholds to determine significant changes in microarray data analyses

    Directory of Open Access Journals (Sweden)

    Li Xinmin

    2005-01-01

    Full Text Available The use of a constant fold-change to determine significant changes in gene expression has been widely accepted for its intuition and ease of use in microarray data analysis, but this concept has been increasingly criticized because it does not reflect signal intensity and can result in a substantial number of false positives and false negatives. To resolve this dilemma, we have analyzed 65 replicate Affymetrix chip-chip comparisons and determined a series of user adjustable signal-dependent thresholds which do not require replicates and offer a 95% confidence interval. Quantitative RT-PCR shows that such thresholds significantly improve the power to discriminate biological changes in mRNA from noise and reduce false calls compared to the traditional two-fold threshold. The user-friendly nature of this approach means that it can be easily applied by any user of microarray analysis, even those without any specialized knowledge of computational techniques or statistics. Noise is a function of signal intensity not only for Affymetrix data but also for cDNA array data, analysis of which may also be benefited by our methodology.

  2. Microarray-Based Analysis of Differential Gene Expression between Infective and Noninfective Larvae of Strongyloides stercoralis

    Science.gov (United States)

    Ramanathan, Roshan; Varma, Sudhir; Ribeiro, José M. C.; Myers, Timothy G.; Nolan, Thomas J.; Abraham, David; Lok, James B.; Nutman, Thomas B.

    2011-01-01

    Background Differences between noninfective first-stage (L1) and infective third-stage (L3i) larvae of parasitic nematode Strongyloides stercoralis at the molecular level are relatively uncharacterized. DNA microarrays were developed and utilized for this purpose. Methods and Findings Oligonucleotide hybridization probes for the array were designed to bind 3,571 putative mRNA transcripts predicted by analysis of 11,335 expressed sequence tags (ESTs) obtained as part of the Nematode EST project. RNA obtained from S. stercoralis L3i and L1 was co-hybridized to each array after labeling the individual samples with different fluorescent tags. Bioinformatic predictions of gene function were developed using a novel cDNA Annotation System software. We identified 935 differentially expressed genes (469 L3i-biased; 466 L1-biased) having two-fold expression differences or greater and microarray signals with a p valuemicroarray tool for the examination of S. stercoralis biology has been developed and provides new and valuable insights regarding differences between infective and noninfective S. stercoralis larvae. Potential therapeutic and vaccine targets were identified for further study. PMID:21572524

  3. Expression microarray reproducibility is improved by optimising purification steps in RNA amplification and labelling

    Directory of Open Access Journals (Sweden)

    Brenton James D

    2004-01-01

    Full Text Available Abstract Background Expression microarrays have evolved into a powerful tool with great potential for clinical application and therefore reliability of data is essential. RNA amplification is used when the amount of starting material is scarce, as is frequently the case with clinical samples. Purification steps are critical in RNA amplification and labelling protocols, and there is a lack of sufficient data to validate and optimise the process. Results Here the purification steps involved in the protocol for indirect labelling of amplified RNA are evaluated and the experimentally determined best method for each step with respect to yield, purity, size distribution of the transcripts, and dye coupling is used to generate targets tested in replicate hybridisations. DNase treatment of diluted total RNA samples followed by phenol extraction is the optimal way to remove genomic DNA contamination. Purification of double-stranded cDNA is best achieved by phenol extraction followed by isopropanol precipitation at room temperature. Extraction with guanidinium-phenol and Lithium Chloride precipitation are the optimal methods for purification of amplified RNA and labelled aRNA respectively. Conclusion This protocol provides targets that generate highly reproducible microarray data with good representation of transcripts across the size spectrum and a coefficient of repeatability significantly better than that reported previously.

  4. Comparison of gene expression microarray data with count-based RNA measurements informs microarray interpretation.

    Science.gov (United States)

    Richard, Arianne C; Lyons, Paul A; Peters, James E; Biasci, Daniele; Flint, Shaun M; Lee, James C; McKinney, Eoin F; Siegel, Richard M; Smith, Kenneth G C

    2014-08-04

    Although numerous investigations have compared gene expression microarray platforms, preprocessing methods and batch correction algorithms using constructed spike-in or dilution datasets, there remains a paucity of studies examining the properties of microarray data using diverse biological samples. Most microarray experiments seek to identify subtle differences between samples with variable background noise, a scenario poorly represented by constructed datasets. Thus, microarray users lack important information regarding the complexities introduced in real-world experimental settings. The recent development of a multiplexed, digital technology for nucleic acid measurement enables counting of individual RNA molecules without amplification and, for the first time, permits such a study. Using a set of human leukocyte subset RNA samples, we compared previously acquired microarray expression values with RNA molecule counts determined by the nCounter Analysis System (NanoString Technologies) in selected genes. We found that gene measurements across samples correlated well between the two platforms, particularly for high-variance genes, while genes deemed unexpressed by the nCounter generally had both low expression and low variance on the microarray. Confirming previous findings from spike-in and dilution datasets, this "gold-standard" comparison demonstrated signal compression that varied dramatically by expression level and, to a lesser extent, by dataset. Most importantly, examination of three different cell types revealed that noise levels differed across tissues. Microarray measurements generally correlate with relative RNA molecule counts within optimal ranges but suffer from expression-dependent accuracy bias and precision that varies across datasets. We urge microarray users to consider expression-level effects in signal interpretation and to evaluate noise properties in each dataset independently.

  5. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  6. [cDNA library construction from panicle meristem of finger millet].

    Science.gov (United States)

    Radchuk, V; Pirko, Ia V; Isaenkov, S V; Emets, A I; Blium, Ia B

    2014-01-01

    The protocol for production of full-size cDNA using SuperScript Full-Length cDNA Library Construction Kit II (Invitrogen) was tested and high quality cDNA library from meristematic tissue of finger millet panicle (Eleusine coracana (L.) Gaertn) was created. The titer of obtained cDNA library comprised 3.01 x 10(5) CFU/ml in avarage. In average the length of cDNA insertion consisted about 1070 base pairs, the effectivity of cDNA fragment insertions--99.5%. The selective sequencing of cDNA clones from created library was performed. The sequences of cDNA clones were identified with usage of BLAST-search. The results of cDNA library analysis and selective sequencing represents prove good functionality and full length character of inserted cDNA clones. Obtained cDNA library from meristematic tissue of finger millet panicle represents good and valuable source for isolation and identification of key genes regulating metabolism and meristematic development and for mining of new molecular markers to conduct out high quality genetic investigations and molecular breeding as well.

  7. Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia adhesion

    Directory of Open Access Journals (Sweden)

    Faisal Mohamed

    2010-05-01

    Full Text Available Abstract Background The zebra mussel (Dreissena polymorpha has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. Results In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A, current velocity (Factor B, dissolved oxygen (Factor C, and byssogenesis status (Factor D. Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR. The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. Conclusions The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment.

  8. Factorial microarray analysis of zebra mussel (Dreissena polymorpha: Dreissenidae, Bivalvia) adhesion.

    Science.gov (United States)

    Xu, Wei; Faisal, Mohamed

    2010-05-28

    The zebra mussel (Dreissena polymorpha) has been well known for its expertise in attaching to substances under the water. Studies in past decades on this underwater adhesion focused on the adhesive protein isolated from the byssogenesis apparatus of the zebra mussel. However, the mechanism of the initiation, maintenance, and determination of the attachment process remains largely unknown. In this study, we used a zebra mussel cDNA microarray previously developed in our lab and a factorial analysis to identify the genes that were involved in response to the changes of four factors: temperature (Factor A), current velocity (Factor B), dissolved oxygen (Factor C), and byssogenesis status (Factor D). Twenty probes in the microarray were found to be modified by one of the factors. The transcription products of four selected genes, DPFP-BG20_A01, EGP-BG97/192_B06, EGP-BG13_G05, and NH-BG17_C09 were unique to the zebra mussel foot based on the results of quantitative reverse transcription PCR (qRT-PCR). The expression profiles of these four genes under the attachment and non-attachment were also confirmed by qRT-PCR and the result is accordant to that from microarray assay. The in situ hybridization with the RNA probes of two identified genes DPFP-BG20_A01 and EGP-BG97/192_B06 indicated that both of them were expressed by a type of exocrine gland cell located in the middle part of the zebra mussel foot. The results of this study suggested that the changes of D. polymorpha byssogenesis status and the environmental factors can dramatically affect the expression profiles of the genes unique to the foot. It turns out that the factorial design and analysis of the microarray experiment is a reliable method to identify the influence of multiple factors on the expression profiles of the probesets in the microarray; therein it provides a powerful tool to reveal the mechanism of zebra mussel underwater attachment.

  9. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  10. Investigation of cellular signalling responses to non-ionising radiation in melanocytes by microarray analysis

    International Nuclear Information System (INIS)

    Boyle, G.M.; Pedley, J.; Martyn, A.C.; Fraser, L.M.; Banducci, K.J.; Parsons, P.G.; Breit, S.N.

    2003-01-01

    Melanoma is a highly aggressive cancer resulting from the abnormal proliferation and spread of specialised pigment cells in the skin, known as melanocytes. Extensive epidemiological and molecular evidence suggests that a major risk factor for melanoma formation is exposure to non-ionising radiation in the form of solar ultra-violet (UV) light. However, the exact role of solar UV in the development of melanoma is unclear. To elucidate the molecular events that occur in melanocytes following solar UV exposure and determine how they lead to melanoma development, cDNA microarray analysis was used to analyse the gene expression profile of normal melanocytes, melanocytes exposed to simulated solar UV and melanoma cells. The development of cDNA microarray technology has allowed gene expression profiling at the mRNA level to be conducted for many thousands of genes simultaneously by hybridising an array of known sequences with labelled cDNA reverse transcribed form the sample RNA. Gene expression analysis was performed for over 13,000 genes. More than 500 genes were identified as differentially expressed in melanocytes following a single UV exposure, although overall there was a general suppression of transcription. Genes that were up-regulated included oncogenes and cytoskeletal genes; in contrast, genes encoding protein tyrosine kinases and apoptosis effectors were down-regulated. Many of the genes identified as being differentially expressed represent novel UV-regulated targets. Repeated exposure to solar UV resulted in the elevation in expression of a novel member of the transforming growth factor-b (TGF-b) superfamily, the Macrophage Inhibitory Cytokine-1 (MIC-1). Our results have shown that MIC-1 is up-regulated by solar UV in melanocytes, and is highly expressed (>3 fold) in a number of metastatic melanoma cell lines (31/61) in comparison to primary melanocytes. Furthermore functional, dimerised MIC-1 was found to be secreted by melanocytes, and secreted levels were

  11. [Construction and identification of the expression library of album pollen allergens cDNA].

    Science.gov (United States)

    Zhang, Jie; Sun, Xiu-zhen; Yan, Hong; Zhang, Ni; Feng, Xiang-li

    2011-05-01

    To construct and identify the express library of album pollen allergens cDNA. Total RNA were extracted from the album pollen with TRIzol reagent and the mRNA was isolate for the amplify followed. A double stranded cDNA (ds cDNA) was synthesized using primers containing Xho I and Poly(dT) sequence by ZAP Express®cDNA synthesis kit. The ds cDNA was modified and purified by gel chromatography, and then the cDNA fragment with the length of more than 400 bp containing sticky ends was obtained. The cDNA fragment was ligated with Uni-ZAP XR vector and subsequently treated with in vitro packaging using phage by ZAP-cDNA express GigapackIII Gold cloning kit. The express library of album pollen cDNA was constructed by in vitro packaging. The recombination rate and the lengths of fragments inserted of the cDNA library were detected by polymerase chain reaction. The titer and the recombination rate of cDNA expression library constructed were 9.7×10(5) and 100%, respectively. The capacity of the library was 4.85 Pfu. The average length of cDNA fragments inserted was about 1.0 kb. Based on the capacity of cDNA expression library constructed and the length of cDNA insertion fragments, the cDNA expression library constructed is qualified to screening target cDNA clone, laying the foundation for preparation of gene recombinant allergen pollen vaccine.

  12. EMMA 2 – A MAGE-compliant system for the collaborative analysis and integration of microarray data

    Directory of Open Access Journals (Sweden)

    Mertens Dominik

    2009-02-01

    Full Text Available Abstract Background Understanding transcriptional regulation by genome-wide microarray studies can contribute to unravel complex relationships between genes. Attempts to standardize the annotation of microarray data include the Minimum Information About a Microarray Experiment (MIAME recommendations, the MAGE-ML format for data interchange, and the use of controlled vocabularies or ontologies. The existing software systems for microarray data analysis implement the mentioned standards only partially and are often hard to use and extend. Integration of genomic annotation data and other sources of external knowledge using open standards is therefore a key requirement for future integrated analysis systems. Results The EMMA 2 software has been designed to resolve shortcomings with respect to full MAGE-ML and ontology support and makes use of modern data integration techniques. We present a software system that features comprehensive data analysis functions for spotted arrays, and for the most common synthesized oligo arrays such as Agilent, Affymetrix and NimbleGen. The system is based on the full MAGE object model. Analysis functionality is based on R and Bioconductor packages and can make use of a compute cluster for distributed services. Conclusion Our model-driven approach for automatically implementing a full MAGE object model provides high flexibility and compatibility. Data integration via SOAP-based web-services is advantageous in a distributed client-server environment as the collaborative analysis of microarray data is gaining more and more relevance in international research consortia. The adequacy of the EMMA 2 software design and implementation has been proven by its application in many distributed functional genomics projects. Its scalability makes the current architecture suited for extensions towards future transcriptomics methods based on high-throughput sequencing approaches which have much higher computational requirements than

  13. Deep learning for tissue microarray image-based outcome prediction in patients with colorectal cancer

    Science.gov (United States)

    Bychkov, Dmitrii; Turkki, Riku; Haglund, Caj; Linder, Nina; Lundin, Johan

    2016-03-01

    Recent advances in computer vision enable increasingly accurate automated pattern classification. In the current study we evaluate whether a convolutional neural network (CNN) can be trained to predict disease outcome in patients with colorectal cancer based on images of tumor tissue microarray samples. We compare the prognostic accuracy of CNN features extracted from the whole, unsegmented tissue microarray spot image, with that of CNN features extracted from the epithelial and non-epithelial compartments, respectively. The prognostic accuracy of visually assessed histologic grade is used as a reference. The image data set consists of digitized hematoxylin-eosin (H and E) stained tissue microarray samples obtained from 180 patients with colorectal cancer. The patient samples represent a variety of histological grades, have data available on a series of clinicopathological variables including long-term outcome and ground truth annotations performed by experts. The CNN features extracted from images of the epithelial tissue compartment significantly predicted outcome (hazard ratio (HR) 2.08; CI95% 1.04-4.16; area under the curve (AUC) 0.66) in a test set of 60 patients, as compared to the CNN features extracted from unsegmented images (HR 1.67; CI95% 0.84-3.31, AUC 0.57) and visually assessed histologic grade (HR 1.96; CI95% 0.99-3.88, AUC 0.61). As a conclusion, a deep-learning classifier can be trained to predict outcome of colorectal cancer based on images of H and E stained tissue microarray samples and the CNN features extracted from the epithelial compartment only resulted in a prognostic discrimination comparable to that of visually determined histologic grade.

  14. Production of DNA microarray and expression analysis of genes from Xylella fastidiosa in different culture media

    Directory of Open Access Journals (Sweden)

    Regiane de Fátima Travensolo

    2009-06-01

    Full Text Available DNA Microarray was developed to monitor the expression of many genes from Xylella fastidiosa, allowing the side by-side comparison of two situations in a single experiment. The experiments were performed using X. fastidiosa cells grown in two culture media: BCYE and XDM2. The primers were synthesized, spotted onto glass slides and the array was hybridized against fluorescently labeled cDNAs. The emitted signals were quantified, normalized and the data were statistically analyzed to verify the differentially expressed genes. According to the data, 104 genes were differentially expressed in XDM2 and 30 genes in BCYE media. The present study showed that DNA microarray technique efficiently differentiate the expressed genes under different conditions.DNA Microarray foi desenvolvida para monitorar a expressão de muitos genes de Xylella fastidiosa, permitindo a comparação de duas situações distintas em um único experimento. Os experimentos foram feitos utilizando células de X. fastidiosa cultivada em dois meios de cultura: BCYE e XDM2. Pares de oligonucleotídeos iniciadores foram sintetizados, depositados em lâminas de vidro e o arranjo foi hibridizado contra cDNAs marcados fluorescentemente. Os sinais emitidos foram quantificados, normalizados e os dados foram estatisticamente analisados para verificar os genes diferencialmente expressos. De acordo com nossos dados, 104 genes foram diferencialmente expressos para o meio de cultura XDM2 e 30 genes para o BCYE. No presente estudo, nós demonstramos que a técnica de DNA microarrays eficientemente diferencia genes expressos sob diferentes condições de cultivo.

  15. Preparation of a differentially expressed, full-length cDNA expression library by RecA-mediated triple-strand formation with subtractively enriched cDNA fragments

    NARCIS (Netherlands)

    Hakvoort, T. B.; Spijkers, J. A.; Vermeulen, J. L.; Lamers, W. H.

    1996-01-01

    We have developed a fast and general method to obtain an enriched, full-length cDNA expression library with subtractively enriched cDNA fragments. The procedure relies on RecA-mediated triple-helix formation of single-stranded cDNA fragments with a double-stranded cDNA plasmid library. The complexes

  16. Microarray analysis of gene expression on herbal glycoside recipes improving deficient ability of spatial learning memory in ischemic mice.

    Science.gov (United States)

    Wang, Zhong; Du, Qingyou; Wang, Fusheng; Liu, Zhongrong; Li, Baigang; Wang, Anmin; Wang, Yongyan

    2004-03-01

    In order to reveal the mechanism of herbal glycoside recipes retrieving deficient ability of spatial learning memory in mice suffering from cerebral ischemia/reperfusion, a microarray system was used to analyze gene expression in those groups with increasing ability of spatial learning memory who were different from ischemic mice. In this work, we reported a comprehensive characterization of gene expression profiles of mouse hippocampus by the use of cDNA microarray system containing 1176 known genes in middle cerebral artery occlusion (MCAO) ischemic mice after treating with different dosage recipes of glycoside herbs (30, 90, and 270 mg/kg). The ability of spatial learning memory in ischemic mice was found to be decreased. The pathological process in ischemic mouse brain showed that a complex related to 100 genes' expression yielded 1.8-fold. Dose-dependent effects showed an improvement in the deficient ability and reduction in infarct volume when treated with glycoside recipes. Many genes (38-46) in expression were found greater than 1.8-fold in those effective recipes groups, including genes in cell cycle regulation, signal transduction, nerve system transcription factors, DNA binding protein, etc. Nine genes related to retrieving deficient ability of spatial learning memory treated with glycoside recipes were also found in this study. These results suggest that microarray analysis of gene expression might be useful for elucidating the mechanisms of pharmacological function of recipes.

  17. Toward a cDNA map of the human genome

    Energy Technology Data Exchange (ETDEWEB)

    Korenberg, J.R.; Chen, X.N. [Cedars-Sinai Research Institute, Los Angeles, CA (United States); Adams, M.D.; Venter, J.C. [Institute for Genomic Research, Gaithersburg, MD (United States)

    1995-09-20

    Advances in the Human Genome Project are shaping the strategies for identifying the 50,000-100,000 human genes. High-resolution genetic maps of the human genome combined with sequencing herald an era of rapid regional definition of disease genes. However, only once their chromosomes band location is known will the systematic partial sequencing of thousands of random cDNA clones provide the reagents for the rapid assessment of the genes responsible for the inherited disorders. We now present an approach to the rapid determination of map position and therefore to the creation of a transcribed map of the human genome. Sensitive fluorescence in situ hybridization has been combined with high-resolution chromosome banding and random cDNA sequencing to 41 cDNAs with an average insert size of < 2 kb to single human chromosome bands. The results provide 15 new genes, with database and functional information, as candidates for human disease. These include the large extracellular single-related kinase (HUMERK), the ERK activator kinase (PRKMK1), a new member of the RAS oncogene family, protein phosphotase 2 regulatory subunit B alpha isoform (PPP2R2A), and a novel human gene with very high homology to a plant membrane transport family. Further, an analysis of expressed genes associated with pseudogenes showed that by using these techniques, it is possible to detect accurately the transcribed locus within a multigene or processed pseudogene family in most cases. These findings suggest that direct cDNA mapping using fluorescence in situ hybridization provides an accurate and rapid approach to the definition of a transcribed map of the human genome. This low-cost, high-resolution (205 Mb) mapping greatly enhances the speed with which these genes can be subsequently assigned to contigs. This assignment provides a necessary first step in understanding the relationship of the genes to both acquired and inherited human diseases. 16 refs., 1 fig., 3 tabs.

  18. Viral diagnosis in Indian livestock using customized microarray chips.

    Science.gov (United States)

    Yadav, Brijesh S; Pokhriyal, Mayank; Ratta, Barkha; Kumar, Ajay; Saxena, Meeta; Sharma, Bhaskar

    2015-01-01

    Viral diagnosis in Indian livestock using customized microarray chips is gaining momentum in recent years. Hence, it is possible to design customized microarray chip for viruses infecting livestock in India. Customized microarray chips identified Bovine herpes virus-1 (BHV-1), Canine Adeno Virus-1 (CAV-1), and Canine Parvo Virus-2 (CPV-2) in clinical samples. Microarray identified specific probes were further confirmed using RT-PCR in all clinical and known samples. Therefore, the application of microarray chips during viral disease outbreaks in Indian livestock is possible where conventional methods are unsuitable. It should be noted that customized application requires a detailed cost efficiency calculation.

  19. Generation of a large scale repertoire of Expressed Sequence Tags (ESTs from normalised rainbow trout cDNA libraries

    Directory of Open Access Journals (Sweden)

    Guiguen Yann

    2006-08-01

    Full Text Available Abstract Background Within the framework of a genomics project on livestock species (AGENAE, we initiated a high-throughput DNA sequencing program of Expressed Sequence Tags (ESTs in rainbow trout, Oncorhynchus mykiss. Results We constructed three cDNA libraries including one highly complex pooled-tissue library. These libraries were normalized and subtracted to reduce clone redundancy. ESTs sequences were produced, and 96 472 ESTs corresponding to high quality sequence reads were released on the international database, currently representing 42.5% of the overall sequence knowledge in this species. All these EST sequences and other publicly available ESTs in rainbow trout have been included on a publicly available Website (SIGENAE and have been clustered into a total of 52 930 clusters of putative transcripts groups, including 24 616 singletons. 57.1% of these 52 930 clusters are represented by at least one Agenae EST and 14 343 clusters (27.1% are only composed by Agenae ESTs. Sequence analysis also reveals that normalization and especially subtraction were effective in decreasing redundancy, and that the pooled-tissue library was representative of the initial tissue complexity. Conclusion Due to present work on the construction of rainbow trout normalized cDNA libraries and their extensive sequencing, along with other large scale sequencing programs, rainbow trout is now one of the major fish models in term of EST sequences available in a public database, just after Zebrafish, Danio rerio. This information is now used for the selection of a non redundant set of clones for producing DNA micro-arrays in order to examine global gene expression.

  20. Construction and characterization of a normalized cDNA library.

    OpenAIRE

    Soares, M B; Bonaldo, M F; Jelene, P; Su, L; Lawton, L; Efstratiadis, A

    1994-01-01

    We have developed a simple procedure based on reassociation kinetics that can reduce effectively the high variation in abundance among the clones of a cDNA library that represent individual mRNA species. For this normalization, we used as a model system a library of human infant brain cDNAs that were cloned directionally into a phagemid vector and, thus, could be easily converted into single-stranded circles. After controlled primer extension to synthesize a short complementary strand on each...

  1. Facilitating RNA structure prediction with microarrays.

    Science.gov (United States)

    Kierzek, Elzbieta; Kierzek, Ryszard; Turner, Douglas H; Catrina, Irina E

    2006-01-17

    Determining RNA secondary structure is important for understanding structure-function relationships and identifying potential drug targets. This paper reports the use of microarrays with heptamer 2'-O-methyl oligoribonucleotides to probe the secondary structure of an RNA and thereby improve the prediction of that secondary structure. When experimental constraints from hybridization results are added to a free-energy minimization algorithm, the prediction of the secondary structure of Escherichia coli 5S rRNA improves from 27 to 92% of the known canonical base pairs. Optimization of buffer conditions for hybridization and application of 2'-O-methyl-2-thiouridine to enhance binding and improve discrimination between AU and GU pairs are also described. The results suggest that probing RNA with oligonucleotide microarrays can facilitate determination of secondary structure.

  2. Respiratory Tularemia:Francisella Tularensisand Microarray Probe Designing.

    Science.gov (United States)

    Ranjbar, Reza; Behzadi, Payam; Mammina, Caterina

    2016-01-01

    Francisella tularensis ( F. tularensis ) is the etiological microorganism for tularemia. There are different forms of tularemia such as respiratory tularemia. Respiratory tularemia is the most severe form of tularemia with a high rate of mortality; if not treated. Therefore, traditional microbiological tools and Polymerase Chain Reaction (PCR) are not useful for a rapid, reliable, accurate, sensitive and specific diagnosis. But, DNA microarray technology does. DNA microarray technology needs to appropriate microarray probe designing. The main goal of this original article was to design suitable long oligo microarray probes for detection and identification of F. tularensis . For performing this research, the complete genomes of F. tularensis subsp. tularensis FSC198, F. tularensis subsp. holarctica LVS, F. tularensis subsp. mediasiatica , F. tularensis subsp. novicida ( F. novicida U112), and F. philomiragia subsp. philomiragia ATCC 25017 were studied via NCBI BLAST tool, GView and PanSeq Servers and finally the microarray probes were produced and processed via AlleleID 7.7 software and Oligoanalyzer tool, respectively. In this in silico investigation, a number of long oligo microarray probes were designed for detecting and identifying F. tularensis . Among these probes, 15 probes were recognized as the best candidates for microarray chip designing. Calibrated microarray probes reduce the biasis of DNA microarray technology as an advanced, rapid, accurate and cost-effective molecular diagnostic tool with high specificity and sensitivity. Professional microarray probe designing provides us with much more facility and flexibility regarding preparation of a microarray diagnostic chip.

  3. [Construction and Identification of the cDNA Expression Library for Human Esophageal Cancer Cells].

    Science.gov (United States)

    Zhang, Zhe; Wu, Xiang-Yu; Feng, Lu; Huang, Shang-Ke; Luo, Min-Na; Shao, Shan; Zhao, Xin-Han

    2016-09-01

    To construct a cDNA phage expression library for human esophageal cancer cells. After the total RNA were obtained from esophageal cancer cells, the mRNA were separated with magnetic beads adsorption method, and the single-strand and double-strand cDNA were synthesized through reverse transcription. With the undesirable cDNA fragments removed, the remaining cDNA (linked with Eco R1 aptamer and phosphorylated its 5'end) combined with the carrier of T7 Select10-3b. The recombinant phage were packaged in vitro for preliminary cDNA library. PCR was used to identify the size of inserted cDNA. The constructed original cDNA phage expression library for human esophageal cancer cells was consisted of 2.01×10⁶ pfu/mL bacteriophages with a recombination rate of 100%. The length of the inserted cDNA fragments were range from 300 bp to 1 500 bp. The cDNA phage expression library of human esophageal cell is successfully constructed to meet the currently recognized standards, and can be well used to screen cDNA-cloned genes of human esophageal cancer antigens by serological analysis of recombinantly expressed cDNA clone (SEREX).

  4. PMD: A Resource for Archiving and Analyzing Protein Microarray data.

    Science.gov (United States)

    Xu, Zhaowei; Huang, Likun; Zhang, Hainan; Li, Yang; Guo, Shujuan; Wang, Nan; Wang, Shi-Hua; Chen, Ziqing; Wang, Jingfang; Tao, Sheng-Ce

    2016-01-27

    Protein microarray is a powerful technology for both basic research and clinical study. However, because there is no database specifically tailored for protein microarray, the majority of the valuable original protein microarray data is still not publically accessible. To address this issue, we constructed Protein Microarray Database (PMD), which is specifically designed for archiving and analyzing protein microarray data. In PMD, users can easily browse and search the entire database by experimental name, protein microarray type, and sample information. Additionally, PMD integrates several data analysis tools and provides an automated data analysis pipeline for users. With just one click, users can obtain a comprehensive analysis report for their protein microarray data. The report includes preliminary data analysis, such as data normalization, candidate identification, and an in-depth bioinformatics analysis of the candidates, which include functional annotation, pathway analysis, and protein-protein interaction network analysis. PMD is now freely available at www.proteinmicroarray.cn.

  5. Weighted analysis of general microarray experiments

    Directory of Open Access Journals (Sweden)

    Kristiansson Erik

    2007-10-01

    Full Text Available Abstract Background In DNA microarray experiments, measurements from different biological samples are often assumed to be independent and to have identical variance. For many datasets these assumptions have been shown to be invalid and typically lead to too optimistic p-values. A method called WAME has been proposed where a variance is estimated for each sample and a covariance is estimated for each pair of samples. The current version of WAME is, however, limited to experiments with paired design, e.g. two-channel microarrays. Results The WAME procedure is extended to general microarray experiments, making it capable of handling both one- and two-channel datasets. Two public one-channel datasets are analysed and WAME detects both unequal variances and correlations. WAME is compared to other common methods: fold-change ranking, ordinary linear model with t-tests, LIMMA and weighted LIMMA. The p-value distributions are shown to differ greatly between the examined methods. In a resampling-based simulation study, the p-values generated by WAME are found to be substantially more correct than the alternatives when a relatively small proportion of the genes is regulated. WAME is also shown to have higher power than the other methods. WAME is available as an R-package. Conclusion The WAME procedure is generalized and the limitation to paired-design microarray datasets is removed. The examined other methods produce invalid p-values in many cases, while WAME is shown to produce essentially valid p-values when a relatively small proportion of genes is regulated. WAME is also shown to have higher power than the examined alternative methods.

  6. Tissue Microarray Analysis Applied to Bone Diagenesis

    OpenAIRE

    Barrios Mello, Rafael; Regis Silva, Maria Regina; Seixas Alves, Maria Teresa; Evison, Martin; Guimarães, Marco Aurélio; Francisco, Rafaella Arrabaça; Dias Astolphi, Rafael; Miazato Iwamura, Edna Sadayo

    2017-01-01

    Taphonomic processes affecting bone post mortem are important in forensic, archaeological and palaeontological investigations. In this study, the application of tissue microarray (TMA) analysis to a sample of femoral bone specimens from 20 exhumed individuals of known period of burial and age at death is described. TMA allows multiplexing of subsamples, permitting standardized comparative analysis of adjacent sections in 3-D and of representative cross-sections of a large number of specimens....

  7. Characterisation and correction of signal fluctuations in successive acquisitions of microarray images

    Directory of Open Access Journals (Sweden)

    François Nicolas

    2009-03-01

    Full Text Available Abstract Background There are many sources of variation in dual labelled microarray experiments, including data acquisition and image processing. The final interpretation of experiments strongly relies on the accuracy of the measurement of the signal intensity. For low intensity spots in particular, accurately estimating gene expression variations remains a challenge as signal measurement is, in this case, highly subject to fluctuations. Results To evaluate the fluctuations in the fluorescence intensities of spots, we used series of successive scans, at the same settings, of whole genome arrays. We measured the decrease in fluorescence and we evaluated the influence of different parameters (PMT gain, resolution and chemistry of the slide on the signal variability, at the level of the array as a whole and by intensity interval. Moreover, we assessed the effect of averaging scans on the fluctuations. We found that the extent of photo-bleaching was low and we established that 1 the fluorescence fluctuation is linked to the resolution e.g. it depends on the number of pixels in the spot 2 the fluorescence fluctuation increases as the scanner voltage increases and, moreover, is higher for the red as opposed to the green fluorescence which can introduce bias in the analysis 3 the signal variability is linked to the intensity level, it is higher for low intensities 4 the heterogeneity of the spots and the variability of the signal and the intensity ratios decrease when two or three scans are averaged. Conclusion Protocols consisting of two scans, one at low and one at high PMT gains, or multiple scans (ten scans can introduce bias or be difficult to implement. We found that averaging two, or at most three, acquisitions of microarrays scanned at moderate photomultiplier settings (PMT gain is sufficient to significantly improve the accuracy (quality of the data and particularly those for spots having low intensities and we propose this as a general

  8. Characterisation and correction of signal fluctuations in successive acquisitions of microarray images

    Science.gov (United States)

    Glatigny, Annie; Delacroix, Hervé; Tang, Thomas; François, Nicolas; Aggerbeck, Lawrence; Mucchielli-Giorgi, Marie-Hélène

    2009-01-01

    Background There are many sources of variation in dual labelled microarray experiments, including data acquisition and image processing. The final interpretation of experiments strongly relies on the accuracy of the measurement of the signal intensity. For low intensity spots in particular, accurately estimating gene expression variations remains a challenge as signal measurement is, in this case, highly subject to fluctuations. Results To evaluate the fluctuations in the fluorescence intensities of spots, we used series of successive scans, at the same settings, of whole genome arrays. We measured the decrease in fluorescence and we evaluated the influence of different parameters (PMT gain, resolution and chemistry of the slide) on the signal variability, at the level of the array as a whole and by intensity interval. Moreover, we assessed the effect of averaging scans on the fluctuations. We found that the extent of photo-bleaching was low and we established that 1) the fluorescence fluctuation is linked to the resolution e.g. it depends on the number of pixels in the spot 2) the fluorescence fluctuation increases as the scanner voltage increases and, moreover, is higher for the red as opposed to the green fluorescence which can introduce bias in the analysis 3) the signal variability is linked to the intensity level, it is higher for low intensities 4) the heterogeneity of the spots and the variability of the signal and the intensity ratios decrease when two or three scans are averaged. Conclusion Protocols consisting of two scans, one at low and one at high PMT gains, or multiple scans (ten scans) can introduce bias or be difficult to implement. We found that averaging two, or at most three, acquisitions of microarrays scanned at moderate photomultiplier settings (PMT gain) is sufficient to significantly improve the accuracy (quality) of the data and particularly those for spots having low intensities and we propose this as a general approach. For averaging and

  9. Development of a gold nanoparticle-based universal oligonucleotide microarray for multiplex and low-cost detection of foodborne pathogens.

    Science.gov (United States)

    Wang, Xiaoqiang; Ying, Sisi; Wei, Xiaoguang; Yuan, Jun

    2017-07-17

    Bacterial foodborne diseases remain major threats to food safety and public health, especially in developing countries. In this study a novel assay, combining gold nanoparticle (GNP)-based multiplex oligonucleotide ligation-PCR and universal oligonucleotide microarray technology, was developed for inexpensive, specific, sensitive, and multiplex detection of eight common foodborne pathogens, including Shigella spp., Campylobacter jejuni, Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, and Vibrio parahaemolyticus. The target fragments of the eight pathogens were enriched by multiplex PCR and subjected to multiplex ligase detection reaction. Ligation products were enriched and labeled with GNPs by universal asymmetric PCR, using excess GNP-conjugated primers. The labeled single-stranded amplicons containing complementary tag sequences were captured by the corresponding tag sequences immobilized on microarrays, followed by silver staining for signal enhancement. Black images of microarray spots were visualized by naked eyes or scanned on a simple flatbed scanner, and quantified. The results indicated that this assay could unambiguously discriminate all eight pathogens in single and multiple infections, with detection sensitivity of 3.3-85CFU/mL for pure cultures. Microarray results of ninety-five artificially contaminated and retail food samples were consistent with traditional culture, biochemical and real-time PCR findings. Therefore, the novel assay has the potential to be used for routine detection due to rapidity, low cost, and high specificity and sensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Analyzing microarray data using quantitative association rules.

    Science.gov (United States)

    Georgii, Elisabeth; Richter, Lothar; Rückert, Ulrich; Kramer, Stefan

    2005-09-01

    We tackle the problem of finding regularities in microarray data. Various data mining tools, such as clustering, classification, Bayesian networks and association rules, have been applied so far to gain insight into gene-expression data. Association rule mining techniques used so far work on discretizations of the data and cannot account for cumulative effects. In this paper, we investigate the use of quantitative association rules that can operate directly on numeric data and represent cumulative effects of variables. Technically speaking, this type of quantitative association rules based on half-spaces can find non-axis-parallel regularities. We performed a variety of experiments testing the utility of quantitative association rules for microarray data. First of all, the results should be statistically significant and robust against fluctuations in the data. Next, the approach should be scalable in the number of variables, which is important for such high-dimensional data. Finally, the rules should make sense biologically and be sufficiently different from rules found in regular association rule mining working with discretizations. In all of these dimensions, the proposed approach performed satisfactorily. Therefore, quantitative association rules based on half-spaces should be considered as a tool for the analysis of microarray gene-expression data. The code is available from the authors on request.

  11. Metadata management and semantics in microarray repositories.

    Science.gov (United States)

    Kocabaş, F; Can, T; Baykal, N

    2011-12-01

    The number of microarray and other high-throughput experiments on primary repositories keeps increasing as do the size and complexity of the results in response to biomedical investigations. Initiatives have been started on standardization of content, object model, exchange format and ontology. However, there are backlogs and inability to exchange data between microarray repositories, which indicate that there is a great need for a standard format and data management. We have introduced a metadata framework that includes a metadata card and semantic nets that make experimental results visible, understandable and usable. These are encoded in syntax encoding schemes and represented in RDF (Resource Description Frame-word), can be integrated with other metadata cards and semantic nets, and can be exchanged, shared and queried. We demonstrated the performance and potential benefits through a case study on a selected microarray repository. We concluded that the backlogs can be reduced and that exchange of information and asking of knowledge discovery questions can become possible with the use of this metadata framework.

  12. A New Distribution Family for Microarray Data

    Directory of Open Access Journals (Sweden)

    Diana Mabel Kelmansky

    2017-02-01

    Full Text Available The traditional approach with microarray data has been to apply transformations that approximately normalize them, with the drawback of losing the original scale. The alternative stand point taken here is to search for models that fit the data, characterized by the presence of negative values, preserving their scale; one advantage of this strategy is that it facilitates a direct interpretation of the results. A new family of distributions named gpower-normal indexed by p∈R is introduced and it is proven that these variables become normal or truncated normal when a suitable gpower transformation is applied. Expressions are given for moments and quantiles, in terms of the truncated normal density. This new family can be used to model asymmetric data that include non-positive values, as required for microarray analysis. Moreover, it has been proven that the gpower-normal family is a special case of pseudo-dispersion models, inheriting all the good properties of these models, such as asymptotic normality for small variances. A combined maximum likelihood method is proposed to estimate the model parameters, and it is applied to microarray and contamination data. Rcodes are available from the authors upon request.

  13. Dressing percentage in Romanian spotted breed

    Directory of Open Access Journals (Sweden)

    eleonora nistor

    2013-05-01

    Full Text Available The purpose of this research was to determine whether there are significant differences in terms of carcass weight, forequarters, hindquarters and the dressing percentage among Romanian Spotted breed steers and first generation crossbreed obtained between Romanian Spotted and Holstein at slaughter age of 12 and 17 months respectively. Study was done on Romanian Spotted breed steer aged 12 months (36 heads and 17 months (19 heads; Romanian Spotted x Holstein first generation crossbreed of aged 12 months (29 heads and 17 months (20 heads. The Romanian Spotted breed steer, show superiority in terms of carcass weight compared to crossbreed of Romanian Spotted x Holstein, therefore this breed has a better suitability for fattening for meat. Regarding dressing percentage is higher in crossbreed of Romanian Spotted x Holstein compared with Romanian Spotted breed steers, but the difference is insignificant.

  14. MicroarrayDesigner: an online search tool and repository for near-optimal microarray experimental designs.

    Science.gov (United States)

    Sacan, Ahmet; Ferhatosmanoglu, Nilgun; Ferhatosmanoglu, Hakan

    2009-09-22

    Dual-channel microarray experiments are commonly employed for inference of differential gene expressions across varying organisms and experimental conditions. The design of dual-channel microarray experiments that can help minimize the errors in the resulting inferences has recently received increasing attention. However, a general and scalable search tool and a corresponding database of optimal designs were still missing. An efficient and scalable search method for finding near-optimal dual-channel microarray designs, based on a greedy hill-climbing optimization strategy, has been developed. It is empirically shown that this method can successfully and efficiently find near-optimal designs. Additionally, an improved interwoven loop design construction algorithm has been developed to provide an easily computable general class of near-optimal designs. Finally, in order to make the best results readily available to biologists, a continuously evolving catalog of near-optimal designs is provided. A new search algorithm and database for near-optimal microarray designs have been developed. The search tool and the database are accessible via the World Wide Web at http://db.cse.ohio-state.edu/MicroarrayDesigner. Source code and binary distributions are available for academic use upon request.

  15. MicroarrayDesigner: an online search tool and repository for near-optimal microarray experimental designs

    Directory of Open Access Journals (Sweden)

    Ferhatosmanoglu Nilgun

    2009-09-01

    Full Text Available Abstract Background Dual-channel microarray experiments are commonly employed for inference of differential gene expressions across varying organisms and experimental conditions. The design of dual-channel microarray experiments that can help minimize the errors in the resulting inferences has recently received increasing attention. However, a general and scalable search tool and a corresponding database of optimal designs were still missing. Description An efficient and scalable search method for finding near-optimal dual-channel microarray designs, based on a greedy hill-climbing optimization strategy, has been developed. It is empirically shown that this method can successfully and efficiently find near-optimal designs. Additionally, an improved interwoven loop design construction algorithm has been developed to provide an easily computable general class of near-optimal designs. Finally, in order to make the best results readily available to biologists, a continuously evolving catalog of near-optimal designs is provided. Conclusion A new search algorithm and database for near-optimal microarray designs have been developed. The search tool and the database are accessible via the World Wide Web at http://db.cse.ohio-state.edu/MicroarrayDesigner. Source code and binary distributions are available for academic use upon request.

  16. Multiplex Detection and Genotyping of Point Mutations Involved in Charcot-Marie-Tooth Disease Using a Hairpin Microarray-Based Assay

    Directory of Open Access Journals (Sweden)

    Yasser Baaj

    2009-01-01

    Full Text Available We previously developed a highly specific method for detecting SNPs with a microarray-based system using stem-loop probes. In this paper we demonstrate that coupling a multiplexing procedure with our microarray method is possible for the simultaneous detection and genotyping of four point mutations, in three different genes, involved in Charcot-Marie-Tooth disease. DNA from healthy individuals and patients was amplified, labeled with Cy3 by multiplex PCR; and hybridized to microarrays. Spot signal intensities were 18 to 74 times greater for perfect matches than for mismatched target sequences differing by a single nucleotide (discrimination ratio for “homozygous” DNA from healthy individuals. “Heterozygous” mutant DNA samples gave signal intensity ratios close to 1 at the positions of the mutations as expected. Genotyping by this method was therefore reliable. This system now combines the principle of highly specific genotyping based on stem-loop structure probes with the advantages of multiplex analysis.

  17. Characterization of a cDNA encoding cottonseed catalase.

    Science.gov (United States)

    Ni, W; Turley, R B; Trelease, R N

    1990-06-21

    A 1.7 kb cDNA clone was isolated from our lambda gt11 library constructed from poly(A) RNA of 24-h-old cotyledons. The cDNA encodes a full-length catalase peptide (492 amino acid residues). The calculated molecular mass is 56,800, similar to that determined for purified enzyme (57,000 SDS-PAGE). Among higher plant catalases, this cotton catalase shows the highest amino acid sequence identity (85%) to the subunit of homotetrameric maize CAT 1, a developmental counterpart to the homotetrameric CAT A isoform of cotton seeds. Comparison of sequences from cotton, sweet potato, maize CAT 1, and yeast with bovine catalase revealed that the amino acid residues and regions that are involved in catalytic activity and/or required to maintain basic catalase structure, are highly conserved. The C-terminus region, which has the lowest nucleotide sequence identity between plant and mammalian catalases, does not terminate with a tripeptide, S-K/R/H-L, a putative targeting signal for peroxisomal proteins.

  18. Infectious Maize rayado fino virus from Cloned cDNA.

    Science.gov (United States)

    Edwards, Michael C; Weiland, John J; Todd, Jane; Stewart, Lucy R

    2015-06-01

    A full-length cDNA clone was produced from a U.S. isolate of Maize rayado fino virus (MRFV), the type member of the genus Marafivirus within the family Tymoviridae. Infectivity of transcripts derived from cDNA clones was demonstrated by infection of maize plants and protoplasts, as well as by transmission via the known leafhopper vectors Dalbulus maidis and Graminella nigrifrons that transmit the virus in a persistent-propagative manner. Infection of maize plants through vascular puncture inoculation of seed with transcript RNA resulted in the induction of fine stipple stripe symptoms typical of those produced by wild-type MRFV and a frequency of infection comparable with that of the wild type. Northern and Western blotting confirmed the production of MRFV-specific RNAs and proteins in infected plants and protoplasts. An unanticipated increase in subgenomic RNA synthesis over levels in infected plants was observed in protoplasts infected with either wild-type or cloned virus. A conserved cleavage site motif previously demonstrated to function in both Oat blue dwarf virus capsid protein and tymoviral nonstructural protein processing was identified near the amino terminus of the MRFV replicase polyprotein, suggesting that cleavage at this site also may occur.

  19. Dominant white spotting in the Chinese hamster.

    Science.gov (United States)

    Henwood, C; Henwood, J; Robinson, R

    1987-01-01

    An autosomal dominant white spotting mutant is described for the Chinese hamster. The mutant gene is designated as dominant spot (symbol Ds). The homozygote DsDs is a prenatal lethal while the heterozygote Ds + displays white spotting. The expression of white is variable, ranging from a white forehead spot to extensive white on the body. The venter is invariably white. Growth appears to be normal and the fertility of both sizes shows no impairment.

  20. Laser Pyrometer For Spot Temperature Measurements

    Science.gov (United States)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  1. DNA Microarray for Detection of Gastrointestinal Viruses

    Science.gov (United States)

    Martínez, Miguel A.; Soto-del Río, María de los Dolores; Gutiérrez, Rosa María; Chiu, Charles Y.; Greninger, Alexander L.; Contreras, Juan Francisco; López, Susana; Arias, Carlos F.

    2014-01-01

    Gastroenteritis is a clinical illness of humans and other animals that is characterized by vomiting and diarrhea and caused by a variety of pathogens, including viruses. An increasing number of viral species have been associated with gastroenteritis or have been found in stool samples as new molecular tools have been developed. In this work, a DNA microarray capable in theory of parallel detection of more than 100 viral species was developed and tested. Initial validation was done with 10 different virus species, and an additional 5 species were validated using clinical samples. Detection limits of 1 × 103 virus particles of Human adenovirus C (HAdV), Human astrovirus (HAstV), and group A Rotavirus (RV-A) were established. Furthermore, when exogenous RNA was added, the limit for RV-A detection decreased by one log. In a small group of clinical samples from children with gastroenteritis (n = 76), the microarray detected at least one viral species in 92% of the samples. Single infection was identified in 63 samples (83%), and coinfection with more than one virus was identified in 7 samples (9%). The most abundant virus species were RV-A (58%), followed by Anellovirus (15.8%), HAstV (6.6%), HAdV (5.3%), Norwalk virus (6.6%), Human enterovirus (HEV) (9.2%), Human parechovirus (1.3%), Sapporo virus (1.3%), and Human bocavirus (1.3%). To further test the specificity and sensitivity of the microarray, the results were verified by reverse transcription-PCR (RT-PCR) detection of 5 gastrointestinal viruses. The RT-PCR assay detected a virus in 59 samples (78%). The microarray showed good performance for detection of RV-A, HAstV, and calicivirus, while the sensitivity for HAdV and HEV was low. Furthermore, some discrepancies in detection of mixed infections were observed and were addressed by reverse transcription-quantitative PCR (RT-qPCR) of the viruses involved. It was observed that differences in the amount of genetic material favored the detection of the most abundant

  2. Classification across gene expression microarray studies

    Directory of Open Access Journals (Sweden)

    Kuner Ruprecht

    2009-12-01

    Full Text Available Abstract Background The increasing number of gene expression microarray studies represents an important resource in biomedical research. As a result, gene expression based diagnosis has entered clinical practice for patient stratification in breast cancer. However, the integration and combined analysis of microarray studies remains still a challenge. We assessed the potential benefit of data integration on the classification accuracy and systematically evaluated the generalization performance of selected methods on four breast cancer studies comprising almost 1000 independent samples. To this end, we introduced an evaluation framework which aims to establish good statistical practice and a graphical way to monitor differences. The classification goal was to correctly predict estrogen receptor status (negative/positive and histological grade (low/high of each tumor sample in an independent study which was not used for the training. For the classification we chose support vector machines (SVM, predictive analysis of microarrays (PAM, random forest (RF and k-top scoring pairs (kTSP. Guided by considerations relevant for classification across studies we developed a generalization of kTSP which we evaluated in addition. Our derived version (DV aims to improve the robustness of the intrinsic invariance of kTSP with respect to technologies and preprocessing. Results For each individual study the generalization error was benchmarked via complete cross-validation and was found to be similar for all classification methods. The misclassification rates were substantially higher in classification across studies, when each single study was used as an independent test set while all remaining studies were combined for the training of the classifier. However, with increasing number of independent microarray studies used in the training, the overall classification performance improved. DV performed better than the average and showed slightly less variance. In

  3. Preparation of full-length cDNA libraries: focus on metazoans.

    Science.gov (United States)

    Harada, Masako; Hayashizaki, Yoshihide

    2009-01-01

    Critical steps in a cDNA library preparation include efficient cDNA synthesis, selection of full-length cDNAs, normalizing their abundance, and the subtraction of redundant transcripts. The use of trehalose and sorbiol stabilizes the activity of the reverse transcriptase leading to efficient cDNA synthesis and the cap-trapping method is used for efficient full-length cDNA selection. Through the incorporation of additional normalization and subtraction steps that eliminate the size bias and expressed gene frequency, it is possible to attain cDNA libraries that include larger or rarely expressed genes. This chapter describes an efficient method to construct a full-length cDNA library, with a focus on metazoan samples.

  4. Novel design and controls for focused DNA microarrays: applications in quality assurance/control and normalization for the Health Canada ToxArray™

    Directory of Open Access Journals (Sweden)

    Lambert Iain B

    2006-10-01

    Full Text Available Abstract Background Microarray normalizations typically apply methods that assume absence of global transcript shifts, or absence of changes in internal control features such as housekeeping genes. These normalization approaches are not appropriate for focused arrays with small sets of genes where a large portion may be expected to change. Furthermore, many microarrays lack control features that can be used for quality assurance (QA. Here, we describe a novel external control series integrated with a design feature that addresses the above issues. Results An EC dilution series that involves spike-in of a single concentration of the A. thaliana chlorophyll synthase gene to hybridize against spotted dilutions (0.000015 to 100 μM of a single complimentary oligonucleotide representing the gene was developed. The EC series is printed in duplicate within each subgrid of the microarray and covers the full range of signal intensities from background to saturation. The design and placement of the series allows for QA examination of frequently encountered problems in hybridization (e.g., uneven hybridizations and printing (e.g., cross-spot contamination. Additionally, we demonstrate that the series can be integrated with a LOWESS normalization to improve the detection of differential gene expression (improved sensitivity and predictivity over LOWESS normalization on its own. Conclusion The quality of microarray experiments and the normalization methods used affect the ability to measure accurate changes in gene expression. Novel methods are required for normalization of small focused microarrays, and for incorporating measures of performance and quality. We demonstrate that dilution of oligonucleotides on the microarray itself provides an innovative approach allowing the full dynamic range of the scanner to be covered with a single gene spike-in. The dilution series can be used in a composite normalization to improve detection of differential gene

  5. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  6. Current Knowledge on Microarray Technology - An Overview

    African Journals Online (AJOL)

    Erah

    parallel analytical devices containing libraries of oligonucleotides robotically spotted (printed) or synthesized in situ on solid supports (glass, coated glass, silicon or plastic) in a such way ... by an algorithm that messages the difference between the match and ... images from scanner by importing into a software in which they ...

  7. Sweet Spots and Door Stops

    Science.gov (United States)

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  8. Evaluation of toxicity of the mycotoxin citrinin using yeast ORF DNA microarray and Oligo DNA microarray

    Directory of Open Access Journals (Sweden)

    Nobumasa Hitoshi

    2007-04-01

    Full Text Available Abstract Background Mycotoxins are fungal secondary metabolites commonly present in feed and food, and are widely regarded as hazardous contaminants. Citrinin, one of the very well known mycotoxins that was first isolated from Penicillium citrinum, is produced by more than 10 kinds of fungi, and is possibly spread all over the world. However, the information on the action mechanism of the toxin is limited. Thus, we investigated the citrinin-induced genomic response for evaluating its toxicity. Results Citrinin inhibited growth of yeast cells at a concentration higher than 100 ppm. We monitored the citrinin-induced mRNA expression profiles in yeast using the ORF DNA microarray and Oligo DNA microarray, and the expression profiles were compared with those of the other stress-inducing agents. Results obtained from both microarray experiments clustered together, but were different from those of the mycotoxin patulin. The oxidative stress response genes – AADs, FLR1, OYE3, GRE2, and MET17 – were significantly induced. In the functional category, expression of genes involved in "metabolism", "cell rescue, defense and virulence", and "energy" were significantly activated. In the category of "metabolism", genes involved in the glutathione synthesis pathway were activated, and in the category of "cell rescue, defense and virulence", the ABC transporter genes were induced. To alleviate the induced stress, these cells might pump out the citrinin after modification with glutathione. While, the citrinin treatment did not induce the genes involved in the DNA repair. Conclusion Results from both microarray studies suggest that citrinin treatment induced oxidative stress in yeast cells. The genotoxicity was less severe than the patulin, suggesting that citrinin is less toxic than patulin. The reproducibility of the expression profiles was much better with the Oligo DNA microarray. However, the Oligo DNA microarray did not completely overcome cross

  9. Solid-phase cDNA library construction, a versatile approach.

    OpenAIRE

    Roeder, T

    1998-01-01

    A rapid and versatile method for cDNA library construction was developed. It is based on conventional cDNA library synthesis including all enzymatic steps usually required, but is performed on a solid support. The cDNA is immobilised via a biotin residue to streptavidin coupled magnetic beads, which allows rapid and easy to perform changes of buffers and enzymes. Therefore, it combines speed (library construction within a single day) with high quality libraries, making it ideally suited for m...

  10. Molecular cloning and mammalian expression of human beta 2-glycoprotein I cDNA

    DEFF Research Database (Denmark)

    Kristensen, Torsten; Schousboe, Inger; Boel, Espen

    1991-01-01

    Human β2-glycoprotein (β2gpI) cDNA was isolated from a liver cDNA library and sequenced. The cDNA encoded a 19-residue hydrophobic signal peptide followed by the mature β2gpI of 326 amino acid residues. In liver and in the hepatoma cell line HepG2 there are two mRNA species of about 1.4 and 4.3 kb...

  11. Justifications shape ethical blind spots.

    Science.gov (United States)

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

  12. Functional cloning using pFB retroviral cDNA expression libraries.

    Science.gov (United States)

    Felts, Katherine A; Chen, Keith; Zaharee, Kim; Sundar, Latha; Limjoco, Jamie; Miller, Anna; Vaillancourt, Peter

    2002-09-01

    Retroviral cDNA expression libraries allow the efficient introduction of complex cDNA libraries into virtually any mitotic cell type for screening based on gene function. The cDNA copy number per cell can be easily controlled by adjusting the multiplicity of infection, thus cell populations may be generated in which >90% of infected cells contain one to three cDNAs. We describe the isolation of two known oncogenes and one cell-surface receptor from a human Burkitt's lymphoma (Daudi) cDNA library inserted into the high-titer retroviral vector pFB.

  13. Custom microarray construction and analysis for determining potential biomarkers of subchronic androgen exposure in the Eastern Mosquitofish (Gambusia holbrooki).

    Science.gov (United States)

    Brockmeier, Erica K; Yu, Fahong; Amador, David Moraga; Bargar, Timothy A; Denslow, Nancy D

    2013-09-28

    The eastern mosquitofish (Gambusia holbrooki) has the potential to become a bioindicator organism of endocrine disrupting chemicals (EDCs) due to its androgen-driven secondary sexual characteristics. However, the lack of molecular information on G. holbrooki hinders its use as a bioindicator coupled with biomarker data. While traditional gene-by-gene approaches provide insight for biomarker development, a holistic analysis would provide more rapid and expansive determination of potential biomarkers. The objective of this study was to develop and utilize a mosquitofish microarray to determine potential biomarkers of subchronic androgen exposure. To achieve this objective, two specific aims were developed: 1) Sequence a G. holbrooki cDNA library, and 2) Use microarray analysis to determine genes that are differentially regulated by subchronic androgen exposure in hepatic tissues of 17β-trenbolone (TB) exposed adult female G. holbrooki. A normalized library of multiple organs of male and female G. holbrooki was prepared and sequenced by the Illumina GA IIx and Roche 454 XLR70. Over 30,000 genes with e-value ≤ 10⁻⁴ were annotated and 14,758 of these genes were selected for inclusion on the microarray. Hepatic microarray analysis of adult female G. holbrooki exposed to the vehicle control or 1 μg/L of TB (a potent anabolic androgen) revealed 229 genes upregulated and 279 downregulated by TB (one-way ANOVA, p 1.5 and bioindicator for EDCs. Future studies using this array will enhance knowledge of the biology and toxicological response of this species. This work provides a foundation of molecular knowledge and tools that can be used to delve further into understanding the biology of G. holbrooki and how this organism can be used as a bioindicator organism for endocrine disrupting pollutants in the environment.

  14. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  15. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  16. Normalization for triple-target microarray experiments

    Directory of Open Access Journals (Sweden)

    Magniette Frederic

    2008-04-01

    Full Text Available Abstract Background Most microarray studies are made using labelling with one or two dyes which allows the hybridization of one or two samples on the same slide. In such experiments, the most frequently used dyes are Cy3 and Cy5. Recent improvements in the technology (dye-labelling, scanner and, image analysis allow hybridization up to four samples simultaneously. The two additional dyes are Alexa488 and Alexa494. The triple-target or four-target technology is very promising, since it allows more flexibility in the design of experiments, an increase in the statistical power when comparing gene expressions induced by different conditions and a scaled down number of slides. However, there have been few methods proposed for statistical analysis of such data. Moreover the lowess correction of the global dye effect is available for only two-color experiments, and even if its application can be derived, it does not allow simultaneous correction of the raw data. Results We propose a two-step normalization procedure for triple-target experiments. First the dye bleeding is evaluated and corrected if necessary. Then the signal in each channel is normalized using a generalized lowess procedure to correct a global dye bias. The normalization procedure is validated using triple-self experiments and by comparing the results of triple-target and two-color experiments. Although the focus is on triple-target microarrays, the proposed method can be used to normalize p differently labelled targets co-hybridized on a same array, for any value of p greater than 2. Conclusion The proposed normalization procedure is effective: the technical biases are reduced, the number of false positives is under control in the analysis of differentially expressed genes, and the triple-target experiments are more powerful than the corresponding two-color experiments. There is room for improving the microarray experiments by simultaneously hybridizing more than two samples.

  17. Expression analysis of a ''Cucurbita'' cDNA encoding endonuclease

    International Nuclear Information System (INIS)

    Szopa, J.

    1995-01-01

    The nuclear matrices of plant cell nuclei display intrinsic nuclease activity which consists in nicking supercoiled DNA. A cDNA encoding a 32 kDa endonuclease has been cloned and sequenced. The nucleotide and deduced amino-acid sequences show high homology to known 14-3-3-protein sequences from other sources. The amino-acid sequence shows agreement with consensus sequences for potential phosphorylation by protein kinase A and C and for calcium, lipid and membrane-binding sites. The nucleotide-binding site is also present within the conserved part of the sequence. By Northern blot analysis, the differential expression of the corresponding mRNA was detected; it was the strongest in sink tissues. The endonuclease activity found on DNA-polyacrylamide gel electrophoresis coincided with mRNA content and was the highest in tuber. (author). 22 refs, 6 figs

  18. Antigen microarrays: descriptive chemistry or functional immunomics?

    Science.gov (United States)

    Prechl, József; Papp, Krisztián; Erdei, Anna

    2010-04-01

    Advances in protein microarray technology allow the generation of high content, reliable information about complex, multilevel protein interaction networks. Yet antigen arrays are used mostly only as devices for parallel immune assays describing multitudes of individual binding events. We propose here that the huge amount of immunological information hidden in the plasma of an individual could be better revealed by combining the characterization of antibody binding to target epitopes with improved estimation of effector functions triggered by these binding events. Furthermore, we could generate functional immune profiles characterizing general immune responsiveness of the individual by designing arrays incorporating epitope collections from diverse subsets of antibody targets. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Tumor classification ranking from microarray data

    Directory of Open Access Journals (Sweden)

    Kijsanayothin Phongphun

    2008-09-01

    Full Text Available Abstract Background Gene expression profiles based on microarray data are recognized as potential diagnostic indices of cancer. Molecular tumor classifications resulted from these data and learning algorithms have advanced our understanding of genetic changes associated with cancer etiology and development. However, classifications are not always perfect and in such cases the classification rankings (likelihoods of correct class predictions can be useful for directing further research (e.g., by deriving inferences about predictive indicators or prioritizing future experiments. Classification ranking is a challenging problem, particularly for microarray data, where there is a huge number of possible regulated genes with no known rating function. This study investigates the possibility of making tumor classification more informative by using a method for classification ranking that requires no additional ranking analysis and maintains relatively good classification accuracy. Results Microarray data of 11 different types and subtypes of cancer were analyzed using MDR (Multi-Dimensional Ranker, a recently developed boosting-based ranking algorithm. The number of predictor genes in all of the resulting classification models was at most nine, a huge reduction from the more than 12 thousands genes in the majority of the expression samples. Compared to several other learning algorithms, MDR gives the greatest AUC (area under the ROC curve for the classifications of prostate cancer, acute lymphoblastic leukemia (ALL and four ALL subtypes: BCR-ABL, E2A-PBX1, MALL and TALL. SVM (Support Vector Machine gives the highest AUC for the classifications of lung, lymphoma, and breast cancers, and two ALL subtypes: Hyperdiploid > 50 and TEL-AML1. MDR gives highly competitive results, producing the highest average AUC, 91.01%, and an average overall accuracy of 90.01% for cancer expression analysis. Conclusion Using the classification rankings from MDR is a simple

  20. Linking probe thermodynamics to microarray quantification

    International Nuclear Information System (INIS)

    Li, Shuzhao; Pozhitkov, Alexander; Brouwer, Marius

    2010-01-01

    Understanding the difference in probe properties holds the key to absolute quantification of DNA microarrays. So far, Langmuir-like models have failed to link sequence-specific properties to hybridization signals in the presence of a complex hybridization background. Data from washing experiments indicate that the post-hybridization washing has no major effect on the specifically bound targets, which give the final signals. Thus, the amount of specific targets bound to probes is likely determined before washing, by the competition against nonspecific binding. Our competitive hybridization model is a viable alternative to Langmuir-like models. (comment)

  1. Microarray technology applied to the complex disorder of preeclampsia.

    Science.gov (United States)

    Founds, Sandra A; Dorman, Janice S; Conley, Yvette P

    2008-01-01

    Preeclampsia is a life-threatening perinatal complication with unknown etiology. Microarray technology has characterized global gene expression in complex disorders such as preeclampsia. Nursing research and future practice may incorporate findings from microarray analyses to identify susceptibility to and prevent disease, to diagnose early, and to design and monitor personalized therapies. This overview of microarray technology, with emphasis on how it can inform genomics of preeclampsia, may provide concepts to improve future maternal-neonatal nursing care.

  2. Isolation of full-length putative rat lysophospholipase cDNA using improved methods for mRNA isolation and cDNA cloning

    International Nuclear Information System (INIS)

    Han, J.H.; Stratowa, C.; Rutter, W.J.

    1987-01-01

    The authors have cloned a full-length putative rat pancreatic lysophospholipase cDNA by an improved mRNA isolation method and cDNA cloning strategy using [ 32 P]-labelled nucleotides. These new methods allow the construction of a cDNA library from the adult rat pancreas in which the majority of recombinant clones contained complete sequences for the corresponding mRNAs. A previously recognized but unidentified long and relatively rare cDNA clone containing the entire sequence from the cap site at the 5' end to the poly(A) tail at the 3' end of the mRNA was isolated by single-step screening of the library. The size, amino acid composition, and the activity of the protein expressed in heterologous cells strongly suggest this mRNA codes for lysophospholipase

  3. Detection and identification of enterohemorrhagic Escherichia coli O157:H7 and Vibrio cholerae O139 using oligonucleotide microarray

    Directory of Open Access Journals (Sweden)

    Zhang Zheng

    2007-12-01

    Full Text Available Abstract Background The rapid and accurate detection and identification of the new subtype of the pathogens is crucial for diagnosis, treatment and control of the contagious disease outbreak. Here, in this study, an approach to detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139 was established using oligonucleotide microarray. We coupled multiplex PCR with oligonucleotide microarray to construct an assay suitable for simultaneous identification of two subtypes of the pathogens. Results The stx1, stx2 gene and uidA gene having the specific mutant spot were chosen as the targets for Escherichia coli O157:H7, and meanwhile the ctxA, tcpA, and LPSgt gene for Vibrio cholerae O139. The oligonucleotide microarray was composed of eight probes including negative control and positive control from 16S rDNA gene. The six primers were designed to amplify target fragments in two triplex PCR, and then hybridized with oligonucleotide microarray. An internal control would be to run a PCR reaction in parallel. Multiplex PCR did not produce any non-specific amplicons when 149 related species or genera of standard bacteria were tested (100% specificity. In addition, Escherichia coli O157:H7 and Escherichia coli O157:non-H7, Vibrio cholerae O139 and Vibrio cholerae O1 had been discriminated respectively. Using recombinant plasmid and target pathogens, we were able to detect positive hybridization signals with 102 copies/μL and 103 cfu/mL per reaction. Conclusion The DNA microarray assay reported here could detect and identify Escherichia coli O157:H7 and Vibrio cholerae O139, and furthermore the subtype was distinguished. This assay was a specific and sensitive tool for simultaneous detection and identification of the new subtype of two pathogens causing diarrhea in human.

  4. Prognostic meta-signature of breast cancer developed by two-stage mixture modeling of microarray data

    Directory of Open Access Journals (Sweden)

    Ghosh Debashis

    2004-12-01

    Full Text Available Abstract Background An increasing number of studies have profiled tumor specimens using distinct microarray platforms and analysis techniques. With the accumulating amount of microarray data, one of the most intriguing yet challenging tasks is to develop robust statistical models to integrate the findings. Results By applying a two-stage Bayesian mixture modeling strategy, we were able to assimilate and analyze four independent microarray studies to derive an inter-study validated "meta-signature" associated with breast cancer prognosis. Combining multiple studies (n = 305 samples on a common probability scale, we developed a 90-gene meta-signature, which strongly associated with survival in breast cancer patients. Given the set of independent studies using different microarray platforms which included spotted cDNAs, Affymetrix GeneChip, and inkjet oligonucleotides, the individually identified classifiers yielded gene sets predictive of survival in each study cohort. The study-specific gene signatures, however, had minimal overlap with each other, and performed poorly in pairwise cross-validation. The meta-signature, on the other hand, accommodated such heterogeneity and achieved comparable or better prognostic performance when compared with the individual signatures. Further by comparing to a global standardization method, the mixture model based data transformation demonstrated superior properties for data integration and provided solid basis for building classifiers at the second stage. Functional annotation revealed that genes involved in cell cycle and signal transduction activities were over-represented in the meta-signature. Conclusion The mixture modeling approach unifies disparate gene expression data on a common probability scale allowing for robust, inter-study validated prognostic signatures to be obtained. With the emerging utility of microarrays for cancer prognosis, it will be important to establish paradigms to meta

  5. Chemiluminescence microarrays in analytical chemistry: a critical review.

    Science.gov (United States)

    Seidel, Michael; Niessner, Reinhard

    2014-09-01

    Multi-analyte immunoassays on microarrays and on multiplex DNA microarrays have been described for quantitative analysis of small organic molecules (e.g., antibiotics, drugs of abuse, small molecule toxins), proteins (e.g., antibodies or protein toxins), and microorganisms, viruses, and eukaryotic cells. In analytical chemistry, multi-analyte detection by use of analytical microarrays has become an innovative research topic because of the possibility of generating several sets of quantitative data for different analyte classes in a short time. Chemiluminescence (CL) microarrays are powerful tools for rapid multiplex analysis of complex matrices. A wide range of applications for CL microarrays is described in the literature dealing with analytical microarrays. The motivation for this review is to summarize the current state of CL-based analytical microarrays. Combining analysis of different compound classes on CL microarrays reduces analysis time, cost of reagents, and use of laboratory space. Applications are discussed, with examples from food safety, water safety, environmental monitoring, diagnostics, forensics, toxicology, and biosecurity. The potential and limitations of research on multiplex analysis by use of CL microarrays are discussed in this review.

  6. Lectin-based protein microarray analysis of differences in serum alpha-2-macroglobulin glycosylation between patients with colorectal cancer and persons without cancer.

    Science.gov (United States)

    Šunderić, Miloš; Šedivá, Alena; Robajac, Dragana; Miljuš, Goran; Gemeiner, Peter; Nedić, Olgica; Katrlík, Jaroslav

    2016-07-01

    Glycosylation is co- and posttranslational modifications affecting proteins. The glycopattern changes are associated with changes in biological function and are involved in many diseases including cancer. We present the lectin-based protein microarray method enabling determination of differences in protein glycosylation. The method involves isolation of targeted protein from samples by immunoprecipitation, spotting of protein from multiple samples into arrays on a microarray slide, incubation with set of biotinylated lectins, the reaction with fluorescent conjugate of streptavidin, and detection of fluorescent intensities by microarray scanner. Lectin-based protein microarray was applied in investigation of differences in alpha-2-macroglobulin (α2M) glycosylation isolated from sera samples of healthy persons and patients with colorectal cancer (CC). From 14 lectins used in analysis, statistically significant differences (Student's t-test, P microarray developed and described can serve as a suitable analytical technique for sensitive, simple, fast, and high-throughput determination of differences in protein glycosylation isolated from serum or other samples. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  7. Watermarking spot colors in packaging

    Science.gov (United States)

    Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

    2015-03-01

    In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

  8. Microarray time course experiments: finding profiles.

    Science.gov (United States)

    Irigoien, Itziar; Vives, Sergi; Arenas, Concepción

    2011-01-01

    Time course studies with microarray techniques and experimental replicates are very useful in biomedical research. We present, in replicate experiments, an alternative approach to select and cluster genes according to a new measure for association between genes. First, the procedure normalizes and standardizes the expression profile of each gene, and then, identifies scaling parameters that will further minimize the distance between replicates of the same gene. Then, the procedure filters out genes with a flat profile, detects differences between replicates, and separates genes without significant differences from the rest. For this last group of genes, we define a mean profile for each gene and use it to compute the distance between two genes. Next, a hierarchical clustering procedure is proposed, a statistic is computed for each cluster to determine its compactness, and the total number of classes is determined. For the rest of the genes, those with significant differences between replicates, the procedure detects where the differences between replicates lie, and assigns each gene to the best fitting previously identified profile or defines a new profile. We illustrate this new procedure using simulated data and a representative data set arising from a microarray experiment with replication, and report interesting results.

  9. Additive risk survival model with microarray data

    Directory of Open Access Journals (Sweden)

    Huang Jian

    2007-06-01

    Full Text Available Abstract Background Microarray techniques survey gene expressions on a global scale. Extensive biomedical studies have been designed to discover subsets of genes that are associated with survival risks for diseases such as lymphoma and construct predictive models using those selected genes. In this article, we investigate simultaneous estimation and gene selection with right censored survival data and high dimensional gene expression measurements. Results We model the survival time using the additive risk model, which provides a useful alternative to the proportional hazards model and is adopted when the absolute effects, instead of the relative effects, of multiple predictors on the hazard function are of interest. A Lasso (least absolute shrinkage and selection operator type estimate is proposed for simultaneous estimation and gene selection. Tuning parameter is selected using the V-fold cross validation. We propose Leave-One-Out cross validation based methods for evaluating the relative stability of individual genes and overall prediction significance. Conclusion We analyze the MCL and DLBCL data using the proposed approach. A small number of probes represented on the microarrays are identified, most of which have sound biological implications in lymphoma development. The selected probes are relatively stable and the proposed approach has overall satisfactory prediction power.

  10. Enchytraeus albidus microarray: enrichment, design, annotation and database (EnchyBASE).

    Science.gov (United States)

    Novais, Sara C; Arrais, Joel; Lopes, Pedro; Vandenbrouck, Tine; De Coen, Wim; Roelofs, Dick; Soares, Amadeu M V M; Amorim, Mónica J B

    2012-01-01

    Enchytraeus albidus (Oligochaeta) is an ecologically relevant species used as standard test organisms for risk assessment. Effects of stressors in this species are commonly determined at the population level using reproduction and survival as endpoints. The assessment of transcriptomic responses can be very useful e.g. to understand underlying mechanisms of toxicity with gene expression fingerprinting. In the present paper the following is being addressed: 1) development of suppressive subtractive hybridization (SSH) libraries enriched for differentially expressed genes after metal and pesticide exposures; 2) sequencing and characterization of all generated cDNA inserts; 3) development of a publicly available genomic database on E. albidus. A total of 2100 Expressed Sequence Tags (ESTs) were isolated, sequenced and assembled into 1124 clusters (947 singletons and 177 contigs). From these sequences, 41% matched known proteins in GenBank (BLASTX, e-value ≤ 10(-5)) and 37% had at least one Gene Ontology (GO) term assigned. In total, 5.5% of the sequences were assigned to a metabolic pathway, based on KEGG. With this new sequencing information, an Agilent custom oligonucleotide microarray was designed, representing a potential tool for transcriptomic studies. EnchyBASE (http://bioinformatics.ua.pt/enchybase/) was developed as a web freely available database containing genomic information on E. albidus and will be further extended in the near future for other enchytraeid species. The database so far includes all ESTs generated for E. albidus from three cDNA libraries. This information can be downloaded and applied in functional genomics and transcription studies.

  11. Enchytraeus albidus microarray: enrichment, design, annotation and database (EnchyBASE.

    Directory of Open Access Journals (Sweden)

    Sara C Novais

    Full Text Available Enchytraeus albidus (Oligochaeta is an ecologically relevant species used as standard test organisms for risk assessment. Effects of stressors in this species are commonly determined at the population level using reproduction and survival as endpoints. The assessment of transcriptomic responses can be very useful e.g. to understand underlying mechanisms of toxicity with gene expression fingerprinting. In the present paper the following is being addressed: 1 development of suppressive subtractive hybridization (SSH libraries enriched for differentially expressed genes after metal and pesticide exposures; 2 sequencing and characterization of all generated cDNA inserts; 3 development of a publicly available genomic database on E. albidus. A total of 2100 Expressed Sequence Tags (ESTs were isolated, sequenced and assembled into 1124 clusters (947 singletons and 177 contigs. From these sequences, 41% matched known proteins in GenBank (BLASTX, e-value ≤ 10(-5 and 37% had at least one Gene Ontology (GO term assigned. In total, 5.5% of the sequences were assigned to a metabolic pathway, based on KEGG. With this new sequencing information, an Agilent custom oligonucleotide microarray was designed, representing a potential tool for transcriptomic studies. EnchyBASE (http://bioinformatics.ua.pt/enchybase/ was developed as a web freely available database containing genomic information on E. albidus and will be further extended in the near future for other enchytraeid species. The database so far includes all ESTs generated for E. albidus from three cDNA libraries. This information can be downloaded and applied in functional genomics and transcription studies.

  12. Construction and analysis of a cDNA library from yellow-fruit ginseng

    African Journals Online (AJOL)

    The total RNA was isolated from yellow-fruit ginseng (Panax ginseng C.A. Meyer) leaf tissue. A cDNA library of panax ginseng leaves was constructed by using pDNR-LIB vector according to the SMART cDNA library construction kit protocol. We obtained 378 high quality sequences (GenBank accession number: ...

  13. cDNA table - RPD | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data ...ile URL: ftp://ftp.biosciencedbc.jp/archive/rpd/LATEST/rpd_cdna.zip File size: 15 KB Simple search URL http:...age About This Database Database Description Download License Update History of This Database Site Policy | Contact Us cDNA table - RPD | LSDB Archive ...

  14. [Construction of cDNA library of Magnaporthe grisea with magnetic bead].

    Science.gov (United States)

    Feng, Xu; Xiaoli, Wu; Dewen, Qiu

    2008-06-01

    We constructed cDNA library of Magnaporthe grisea. The good quality cDNA library could facilitate finding proteinaceous elicitors of M. grisea, and elucidating the mechanisms of the M. grisea--rice interaction. The Oligo(dT) combined with the magnetic bead was used to extract mRNA from total RNA of Magnaporthe grisea and as primers to synthesize the first-strand cDNA. Terminal transferase introduced PolyA into 3'terminal of the first cDNA strand, then the PolyA was used for amplifying the second-strand cDNA. Restriction enzyme and adapter were avoided in this research, which could solve technical limitation of the traditional method. Because all reactions were done in one centrifuge tube, this process could reduce the risk of cDNA loss and cross-contamination. The primers designed in this research could clone the amplified cDNAs into expression vector in a desirable orientation. The cDNA library constructed had a high titer of 8.9 x 10(6) cfu/mL, and contained a total clones of 8.9 x 10(7) cfu, with an average inserts size of about 1380 bp. Constructing cDNA library with magnetic bead was a highly efficient method using only small amount of experimental materials within a short period.

  15. Development of a simple and powerful method, cDNA AFLP-SSPAG ...

    African Journals Online (AJOL)

    Differential cDNAs were easily obtained from silver stained cDNA-AFLP separated on polyacylamide gels. The cDNA was then reamplified, cloned and fragments were sequenced. Sequenced clones were used as probes in northern dot blot analyses and library screening. Full-length cDNA was cloned from a library ...

  16. Genomic and cDNA cloning of a novel mouse lipoxygenase gene

    NARCIS (Netherlands)

    Willems van Dijk, K.; Steketee, K.; Havekes, L.; Frants, R.; Hofker, M.

    1995-01-01

    A novel 12- and 15-lipoxygenase related gene was isolated from a mouse strain 129 genomic phage library in a screen with a human 15-lipoxygenase cDNA probe. The complete genomic sequence revealed 14 exons and 13 introns covering 7.3 kb of DNA. The splice junctions were verified from the cDNA

  17. Construction of full-length cDNA library of white flower Salvia ...

    African Journals Online (AJOL)

    In order to screen and isolate secondary metabolite biosynthesis related gene, we construct a cDNA library of white flower Salvia miltiorrhiza bge. f.alba. High quality of total RNA was successfully isolated from roots of white flower S. miltiorrhiza using modified CTAB method. Double strand cDNA was cloned into pDNR-LIB ...

  18. Cloning and functional expression of a human pancreatic islet glucose-transporter cDNA

    International Nuclear Information System (INIS)

    Permutt, M.A.; Koranyi, L.; Keller, K.; Lacy, P.E.; Scharp, D.W.; Mueckler, M.

    1989-01-01

    Previous studies have suggested that pancreatic islet glucose transport is mediated by a high-K m , low-affinity facilitated transporter similar to that expressed in liver. To determine the relationship between islet and liver glucose transporters, liver-type glucose-transporter cDNA clones were isolated from a human liver cDNA library. The liver-type glucose-transporter cDNA clone hybridized to mRNA transcripts of the same size in human liver and pancreatic islet RNA. A cDNA library was prepared from purified human pancreatic islet tissue and screened with human liver-type glucose-transporter cDNA. The authors isolated two overlapping cDNA clones encompassing 2600 base pairs, which encode a pancreatic islet protein identical in sequence to that of the putative liver-type glucose-transporter protein. Xenopus oocytes injected with synthetic mRNA transcribed from a full-length cDNA construct exhibited increased uptake of 2-deoxyglucose, confirming the functional identity of the clone. These cDNA clones can now be used to study regulation of expression of the gene and to assess the role of inherited defects in this gene as a candidate for inherited susceptibility to non-insulin-dependent diabetes mellitus

  19. Cloning and sequence analysis of H. contortus HC58cDNA gene ...

    African Journals Online (AJOL)

    Phylogenetic analysis revealed close evolutionary proximity of the protein sequence to counterpart sequences in the cathepsin B like proteases, suggesting that HC58cDNA was a member of the papain family. Keywords:Haemonchus contortus, HC58cDNA, cathepsin B like protease, papain family. Kenya Veterinarian Vol.

  20. [A novel vector for construction of a cDNA library].

    Science.gov (United States)

    Fedchenko, V I; Kaloshin, A A; Medvedev, A E

    2010-01-01

    A new original vector pEM-(dT)40(f+) has been prepared. It can be used for cDNA library construction from polyadenylated mRNA, isolated from various sources. The pGEM-(dT)40f(+) is initially transformed into single stranded and then into a linear form and its (dT)40 tail at 3'-end is used as the vector-primer for synthesis of the first strand cDNA. The use of a synthetic oligonucleotide complementary to the vector and recombinant DNA results in vector cyclization and synthesis of the second strand cDNA. This approach significantly simplifies cDNA library construction, it does not require PCR reaction (which can induce artifact mutations in cDNA sequences) and restrictase treatment.

  1. Detection of small genomic imbalances using microarray-based multiplex amplifiable probe hybridization.

    Science.gov (United States)

    Patsalis, Philippos C; Kousoulidou, Ludmila; Männik, Katrin; Sismani, Carolina; Zilina, Olga; Parkel, Sven; Puusepp, Helen; Tõnisson, Neeme; Palta, Priit; Remm, Maido; Kurg, Ants

    2007-02-01

    Array-based genome-wide screening methods were recently introduced to clinical practice in order to detect small genomic imbalances that may cause severe genetic disorders. The continuous advancement of such methods plays an extremely important role in diagnostic genetics and medical genomics. We have modified and adapted the original multiplex amplifiable probe hybridization (MAPH) to a novel microarray format providing an important new diagnostic tool for detection of small size copy-number changes in any locus of human genome. Here, we describe the new array-MAPH diagnostic method and show proof of concept through fabrication, interrogation and validation of a human chromosome X-specific array. We have developed new bioinformatic tools and methodology for designing and producing amplifiable hybridization probes (200-600 bp) for array-MAPH. We designed 558 chromosome X-specific probes with median spacing 238 kb and 107 autosomal probes, which were spotted onto microarrays. DNA samples from normal individuals and patients with known and unknown chromosome X aberrations were analyzed for validation. Array-MAPH detected exactly the same deletions and duplications in blind studies, as well as other unknown small size deletions showing its accuracy and sensitivity. All results were confirmed by fluorescence in situ hybridization and probe-specific PCR. Array-MAPH is a new microarray-based diagnostic tool for the detection of small-scale copy-number changes in complex genomes, which may be useful for genotype-phenotype correlations, identification of new genes, studying genetic variation and provision of genetic services.

  2. Experimental Protocol for Detecting Cyanobacteria in Liquid and Solid Samples with an Antibody Microarray Chip.

    Science.gov (United States)

    Blanco, Yolanda; Moreno-Paz, Mercedes; Parro, Victor

    2017-02-07

    Global warming and eutrophication make some aquatic ecosystems behave as true bioreactors that trigger rapid and massive cyanobacterial growth; this has relevant health and economic consequences. Many cyanobacterial strains are toxin producers, and only a few cells are necessary to induce irreparable damage to the environment. Therefore, water-body authorities and administrations require rapid and efficient early-warning systems providing reliable data to support their preventive or curative decisions. This manuscript reports an experimental protocol for the in-field detection of toxin-producing cyanobacterial strains by using an antibody microarray chip with 17 antibodies (Abs) with taxonomic resolution (CYANOCHIP). Here, a multiplex fluorescent sandwich microarray immunoassay (FSMI) for the simultaneous monitoring of 17 cyanobacterial strains frequently found blooming in freshwater ecosystems, some of them toxin producers, is described. A microarray with multiple identical replicates (up to 24) of the CYANOCHIP was printed onto a single microscope slide to simultaneously test a similar number of samples. Liquid samples can be tested either by direct incubation with the antibodies (Abs) or after cell concentration by filtration through a 1- to 3-μm filter. Solid samples, such as sediments and ground rocks, are first homogenized and dispersed by a hand-held ultrasonicator in an incubation buffer. They are then filtered (5 - 20 μm) to remove the coarse material, and the filtrate is incubated with Abs. Immunoreactions are revealed by a final incubation with a mixture of the 17 fluorescence-labeled Abs and are read by a portable fluorescence detector. The whole process takes around 3 h, most of it corresponding to two 1-h periods of incubation. The output is an image, where bright spots correspond to the positive detection of cyanobacterial markers.

  3. Oil futures and spot markets

    International Nuclear Information System (INIS)

    Samii, M.V.

    1992-01-01

    In the last decade, the oil futures market has risen to prominence and has become a major factor in influencing oil market psychology and the crude oil market. On a normal day, over 92 thousand contracts, the equivalent of 92 million barrels per day, change hands on the New York Mercantile Exchange, NYMEX. This market has provided a vehicle for hedging against risk. At the same time, it has also created opportunities for speculation. Those who previously were unable to participate in oil market transactions can now become involved through the futures market. The large number of participants in the future market and the availability of information has made this market more efficient and transparent, relative to the crude oil market. While there has been considerable in-depth analysis of other future markets, relatively little theoretical attention has focused on that of oil. This paper looks at the following issues. First, what is the relationship between futures and spot oil prices? And secondly, are futures prices a good predictor of spot crude prices in the future? (author)

  4. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  5. Three-dimensional (3D) plasma micro-nanotextured slides for high performance biomolecule microarrays: Comparison with epoxy-silane coated glass slides.

    Science.gov (United States)

    Tsougeni, Katerina; Ellinas, Kosmas; Koukouvinos, George; Petrou, Panagiota S; Tserepi, Angeliki; Kakabakos, Sotirios E; Gogolides, Evangelos

    2018-02-25

    Glass slides coated with a poly(methyl methacrylate) layer and plasma micro-nanotextured to acquire 3D topography (referred as 3D micro-nanotextured slides) were evaluated as substrates for biomolecule microarrays. Their performance is compared with that of epoxy-coated glass slides. We found that the proposed three-dimensional (3D) slides offered significant improvements in terms of spot intensity, homogeneity, and reproducibility. In particular, they provided higher spot intensity, by a factor of at least 1.5, and significantly improved spot homogeneity when compared to the epoxy-silane coated ones (intra-spot and between spot coefficients of variation ranging between 5 and 15% for the 3D micro-nanotextured slides and between 25 and 85% for the epoxy-silane coated ones). The latter was to a great extent the result of a strong "coffee-ring" effect observed for the spots created on the epoxy-coated slides; a phenomenon that was severely reduced in the 3D micro-nanotextured slides. The 3D micro-nanotextured slides offered in addition higher signal to noise ratio values over a wide range of protein probe concentrations and shelf-life over one year without requirement for specific storage conditions. Finally, the protocols employed for protein probe immobilization were extremely simple. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Near-optimal designs for dual channel microarray studies

    NARCIS (Netherlands)

    Wit, Ernst; Nobile, Agostino; Khanin, Raya

    2005-01-01

    Much biological and medical research employs microarray studies to monitor gene expression levels across a wide range of organisms and under many experimental conditions. Dual channel microarrays are a common platform and allow two samples to be measured simultaneously. A frequently used design uses

  7. Design of an Enterobacteriaceae Pan-genome Microarray Chip

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Ussery, David

    2010-01-01

    -density microarray chip has been designed, using 116 Enterobacteriaceae genome sequences, taking into account the enteric pan-genome. Probes for the microarray were checked in silico and performance of the chip, based on experimental strains from four different genera, demonstrate a relatively high ability...

  8. Microarray-based Detection of Antibiotic Resisteance Genes in Salmonella

    NARCIS (Netherlands)

    Hoek, van A.H.A.M.; Aarts, H.J.M.

    2008-01-01

    In the presented study, 143 Salmonella isolates belonging to 26 different serovars were screened for the presence of antibiotic resistance genes by microarray analysis. The microarray contained a total of 223 oligonucleotides representing genes encoding for resistance to the following antibiotic

  9. A Critical Perspective On Microarray Breast Cancer Gene Expression Profiling

    NARCIS (Netherlands)

    Sontrop, H.M.J.

    2015-01-01

    Microarrays offer biologists an exciting tool that allows the simultaneous assessment of gene expression levels for thousands of genes at once. At the time of their inception, microarrays were hailed as the new dawn in cancer biology and oncology practice with the hope that within a decade diseases

  10. Shared probe design and existing microarray reanalysis using PICKY

    Directory of Open Access Journals (Sweden)

    Chou Hui-Hsien

    2010-04-01

    Full Text Available Abstract Background Large genomes contain families of highly similar genes that cannot be individually identified by microarray probes. This limitation is due to thermodynamic restrictions and cannot be resolved by any computational method. Since gene annotations are updated more frequently than microarrays, another common issue facing microarray users is that existing microarrays must be routinely reanalyzed to determine probes that are still useful with respect to the updated annotations. Results PICKY 2.0 can design shared probes for sets of genes that cannot be individually identified using unique probes. PICKY 2.0 uses novel algorithms to track sharable regions among genes and to strictly distinguish them from other highly similar but nontarget regions during thermodynamic comparisons. Therefore, PICKY does not sacrifice the quality of shared probes when choosing them. The latest PICKY 2.1 includes the new capability to reanalyze existing microarray probes against updated gene sets to determine probes that are still valid to use. In addition, more precise nonlinear salt effect estimates and other improvements are added, making PICKY 2.1 more versatile to microarray users. Conclusions Shared probes allow expressed gene family members to be detected; this capability is generally more desirable than not knowing anything about these genes. Shared probes also enable the design of cross-genome microarrays, which facilitate multiple species identification in environmental samples. The new nonlinear salt effect calculation significantly increases the precision of probes at a lower buffer salt concentration, and the probe reanalysis function improves existing microarray result interpretations.

  11. Identification of genes related to high royal jelly production in the honey bee (Apis mellifera) using microarray analysis.

    Science.gov (United States)

    Nie, Hongyi; Liu, Xiaoyan; Pan, Jiao; Li, Wenfeng; Li, Zhiguo; Zhang, Shaowu; Chen, Shenglu; Miao, Xiaoqing; Zheng, Nenggan; Su, Songkun

    2017-01-01

    China is the largest royal jelly producer and exporter in the world, and high royal jelly-yielding strains have been bred in the country for approximately three decades. However, information on the molecular mechanism underlying high royal jelly production is scarce. Here, a cDNA microarray was used to screen and identify differentially expressed genes (DEGs) to obtain an overview on the changes in gene expression levels between high and low royal jelly producing bees. We developed a honey bee gene chip that covered 11,689 genes, and this chip was hybridised with cDNA generated from RNA isolated from heads of nursing bees. A total of 369 DEGs were identified between high and low royal jelly producing bees. Amongst these DEGs, 201 (54.47%) genes were up-regulated, whereas 168 (45.53%) were down-regulated in high royal jelly-yielding bees. Gene ontology (GO) analyses showed that they are mainly involved in four key biological processes, and pathway analyses revealed that they belong to a total of 46 biological pathways. These results provide a genetic basis for further studies on the molecular mechanisms involved in high royal jelly production.

  12. Identification of genes related to high royal jelly production in the honey bee (Apis mellifera using microarray analysis

    Directory of Open Access Journals (Sweden)

    Hongyi Nie

    2017-10-01

    Full Text Available Abstract China is the largest royal jelly producer and exporter in the world, and high royal jelly-yielding strains have been bred in the country for approximately three decades. However, information on the molecular mechanism underlying high royal jelly production is scarce. Here, a cDNA microarray was used to screen and identify differentially expressed genes (DEGs to obtain an overview on the changes in gene expression levels between high and low royal jelly producing bees. We developed a honey bee gene chip that covered 11,689 genes, and this chip was hybridised with cDNA generated from RNA isolated from heads of nursing bees. A total of 369 DEGs were identified between high and low royal jelly producing bees. Amongst these DEGs, 201 (54.47% genes were up-regulated, whereas 168 (45.53% were down-regulated in high royal jelly-yielding bees. Gene ontology (GO analyses showed that they are mainly involved in four key biological processes, and pathway analyses revealed that they belong to a total of 46 biological pathways. These results provide a genetic basis for further studies on the molecular mechanisms involved in high royal jelly production.

  13. Microarray Assisted Gene Discovery in Ulcerative Colitis

    DEFF Research Database (Denmark)

    Brusgaard, Klaus

    ), and microarray based expression studies. In IBD the increased production of chemo attractants from the inflamed microenvironment results in recruitment of activated CD4+ T lymphocytes which results in tissue damage. Where Th1 cell-derived cytokines has been reported to be essential mediators in CD with high (IFN...... on the activation of different downstream pathways. Thus it seems that different genetic backgrounds can lead to similar clinical manifestations, and as well determines the susceptibility to IBD. In the previous micro array based expression studies on UC the main target has been to point to new candidate genes...... based on analysis of the main up or down regulated genes in the dataset. The majority of the studies are hampered by a relatively shortcoming of the numbers of genes analysed on the particular array. In this study the main target has been to point to clusters of genes involved in biochemical pathways...

  14. Uses of Dendrimers for DNA Microarrays

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Majoral

    2006-08-01

    Full Text Available Biosensors such as DNA microarrays and microchips are gaining an increasingimportance in medicinal, forensic, and environmental analyses. Such devices are based onthe detection of supramolecular interactions called hybridizations that occur betweencomplementary oligonucleotides, one linked to a solid surface (the probe, and the other oneto be analyzed (the target. This paper focuses on the improvements that hyperbranched andperfectly defined nanomolecules called dendrimers can provide to this methodology. Twomain uses of dendrimers for such purpose have been described up to now; either thedendrimer is used as linker between the solid surface and the probe oligonucleotide, or thedendrimer is used as a multilabeled entity linked to the target oligonucleotide. In the firstcase the dendrimer generally induces a higher loading of probes and an easier hybridization,due to moving away the solid phase. In the second case the high number of localized labels(generally fluorescent induces an increased sensitivity, allowing the detection of smallquantities of biological entities.

  15. Bystander effect: Biological endpoints and microarray analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, M. Ahmad [Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, 302 Rowell Building, Burlington, VT 05405 (United States) and DNA Microarray Facility, University of Vermont, Burlington, VT 05405 (United States)]. E-mail: mchaudhr@uvm.edu

    2006-05-11

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  16. Bystander effect: Biological endpoints and microarray analysis

    International Nuclear Information System (INIS)

    Chaudhry, M. Ahmad

    2006-01-01

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  17. Lipid Microarray Biosensor for Biotoxin Detection.

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anup K.; Throckmorton, Daniel J.; Moran-Mirabal, Jose C.; Edel, Joshua B.; Meyer, Grant D.; Craighead, Harold G.

    2006-05-01

    We present the use of micron-sized lipid domains, patterned onto planar substrates and within microfluidic channels, to assay the binding of bacterial toxins via total internal reflection fluorescence microscopy (TIRFM). The lipid domains were patterned using a polymer lift-off technique and consisted of ganglioside-populated DSPC:cholesterol supported lipid bilayers (SLBs). Lipid patterns were formed on the substrates by vesicle fusion followed by polymer lift-off, which revealed micron-sized SLBs containing either ganglioside GT1b or GM1. The ganglioside-populated SLB arrays were then exposed to either Cholera toxin subunit B (CTB) or Tetanus toxin fragment C (TTC). Binding was assayed on planar substrates by TIRFM down to 1 nM concentration for CTB and 100 nM for TTC. Apparent binding constants extracted from three different models applied to the binding curves suggest that binding of a protein to a lipid-based receptor is strongly affected by the lipid composition of the SLB and by the substrate on which the bilayer is formed. Patterning of SLBs inside microfluidic channels also allowed the preparation of lipid domains with different compositions on a single device. Arrays within microfluidic channels were used to achieve segregation and selective binding from a binary mixture of the toxin fragments in one device. The binding and segregation within the microfluidic channels was assayed with epifluorescence as proof of concept. We propose that the method used for patterning the lipid microarrays on planar substrates and within microfluidic channels can be easily adapted to proteins or nucleic acids and can be used for biosensor applications and cell stimulation assays under different flow conditions. KEYWORDS. Microarray, ganglioside, polymer lift-off, cholera toxin, tetanus toxin, TIRFM, binding constant.4

  18. Construction and characterization of a normalized cDNA library.

    Science.gov (United States)

    Soares, M B; Bonaldo, M F; Jelene, P; Su, L; Lawton, L; Efstratiadis, A

    1994-09-27

    We have developed a simple procedure based on reassociation kinetics that can reduce effectively the high variation in abundance among the clones of a cDNA library that represent individual mRNA species. For this normalization, we used as a model system a library of human infant brain cDNAs that were cloned directionally into a phagemid vector and, thus, could be easily converted into single-stranded circles. After controlled primer extension to synthesize a short complementary strand on each circular template, melting and reannealing of the partial duplexes at relatively low C0t, and hydroxyapatite column chromatography, unreassociated circles were recovered from the flow through fraction and electroporated into bacteria, to propagate a normalized library without a requirement for subcloning steps. An evaluation of the extent of normalization has indicated that, from an extreme range of abundance of 4 orders of magnitude in the original library, the frequency of occurrence of any clone examined in the normalized library was brought within the narrow range of only 1 order of magnitude.

  19. Construction and analysis of SSH cDNA library of human vascular endothelial cells related to gastrocarcinoma

    OpenAIRE

    Liu, Yong-Bo; Wei, Zhao-Xia; Li, Li; Li, Hang-Sheng; Chen, Hui; Li, Xiao-Wen

    2003-01-01

    AIM: To construct subtracted cDNA libraries of human vascular endothelial cells (VECs) related to gastrocarcinoma using suppression substractive hybridization (SSH) and to analyze cDNA libraries of gastrocarcinoma and VECs in Cancer Gene Anatomy Project (CGAP) database.

  20. Hot spots of mutualistic networks.

    Science.gov (United States)

    Gilarranz, Luis J; Sabatino, Malena; Aizen, Marcelo A; Bascompte, Jordi

    2015-03-01

    Incorporating interactions into a biogeographical framework may serve to understand how interactions and the services they provide are distributed in space. We begin by simulating the spatiotemporal dynamics of realistic mutualistic networks inhabiting spatial networks of habitat patches. We proceed by comparing the predicted patterns with the empirical results of a set of pollination networks in isolated hills of the Argentinian Pampas. We first find that one needs to sample up to five times as much area to record interactions as would be needed to sample the same proportion of species. Secondly, we find that peripheral patches have fewer interactions and harbour less nested networks - therefore potentially less resilient communities - compared to central patches. Our results highlight the important role played by the structure of dispersal routes on the spatial distribution of community patterns. This may help to understand the formation of biodiversity hot spots. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  1. Cosmicflows-3: Cold Spot Repeller?

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra [University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN, Lyon (France); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hoffman, Yehuda [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Pomarède, Daniel [Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-09-20

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contribute to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.

  2. SiPM as miniaturised optical biosensor for DNA-microarray applications

    Directory of Open Access Journals (Sweden)

    M.F. Santangelo

    2015-12-01

    Full Text Available A miniaturized optical biosensor for low-level fluorescence emitted by DNA strands labelled with CY5 is showed. Aim of this work is to demonstrate that a Si-based photodetector, having a low noise and a high sensitivity, can replace traditional detection systems in DNA-microarray applications. The photodetector used is a photomultiplier (SiPM, with 25 pixels. It exhibits a higher sensitivity than commercial optical readers and we experimentally found a detection limit for spotted dried samples of ∼1 nM. We measured the fluorescence signal in different operating conditions (angle of analysis, fluorophores concentrations, solution volumes and support. Once fixed the angle of analysis, for samples spotted on Al-TEOS slide dried, the system is proportional to the concentration of the analyte in the sample and is linear in the range 1 nM–1 μM. For solutions, the range of linearity ranges from 100 fM to 10 nM. The system potentialities and the device low costs suggest it as basic component for the design and fabrication of a cheap, easy and portable optical system.

  3. Microarray analysis of choroid/RPE gene expression in marmoset eyes undergoing changes in ocular growth and refraction

    Science.gov (United States)

    Shelton, Lilian; Troilo, David; Lerner, Megan R; Gusev, Yuriy; Brackett, Daniel J

    2008-01-01

    Purpose: Visually guided ocular growth is facilitated by scleral extracellular matrix remodeling at the posterior pole of the eye. Coincident with scleral remodeling, significant changes in choroidal morphology, blood flow, and protein synthesis have been shown to occur in eyes undergoing ocular growth changes. The current study is designed to identify gene expression changes that may occur in the choroid/retinal pigment epithelium (RPE) of marmoset eyes during their compensation for hyperopic defocus as compared to eyes compensating for myopic defocus. Methods: Total RNA was isolated from choroid/RPE from four common marmosets (Callithrix jacchus) undergoing binocular lens treatment using extended wear soft contact lenses of equal magnitude but opposite sign (±5 diopter [D]). After reverse transcription, cDNA was labeled and hybridized to a human oligonucleotide microarray and gene transcript expression profiles were determined. Real-time polymerase chain reaction (PCR) and western blot analysis were used to confirm genes and proteins of interest, respectively. Results: Microarray analyses in choroid/RPE indicated 204 genes were significantly changed in minus lens-treated as compared with plus lens-treated eyes (pscleral remodeling. PMID:18698376

  4. Suppression subtractive hybridization coupled with microarray analysis to examine differential expression of genes in virus infected cells

    Directory of Open Access Journals (Sweden)

    Munir Shirin

    2004-01-01

    Full Text Available High throughput detection of differential expression of genes is an efficient means of identifying genes and pathways that may play a role in biological systems under certain experimental conditions. There exist a variety of approaches that could be used to identify groups of genes that change in expression in response to a particular stimulus or environment. We here describe the application of suppression subtractive hybridization (SSH coupled with cDNA microarray analysis for isolation and identification of chicken transcripts that change in expression on infection of host cells with a paramyxovirus. SSH was used for initial isolation of differentially expressed transcripts, a large-scale validation of which was accomplished by microarray analysis. The data reveals a large group of regulated genes constituting many biochemical pathways that could serve as targets for future investigations to explore their role in paramyxovirus pathogenesis. The detailed methods described herein could be useful and adaptable to any biological system for studying changes in gene expression.

  5. [Construction of a cDNA library from liver tissue of rhesus monkey, Macaca mulatta].

    Science.gov (United States)

    Qin, Sheng-fang; Tan, Wei-dong; Chen, You-nan; Ding, Yang; Li, Sheng-fu; Li, Hong-xia; Wang, Li; Yang, Rong; Lu, Yan-rong

    2007-06-01

    To screen the target rhesus genes and give some basic genetic evidences to its value as one of the most important animal model in biomedical study, we constructed a cDNA expression library from liver tissue of a healthy rhesus monkey. With Trizol reagent, the total RNA was extracted from healthy rhesus liver tissue. By mutant Moloney Murine Leukemia Virus Reverse Transcriptase (MMLV-RT), the first-strand cDNA was synthesized from purified mRNA, and subsequently the second-strand cDNA was generated via E. coli DNA polymerase I . Then, the EcoR I adapter was added to the synthesized double-strand cDNA, which was subsequently digested by Xho I restriction enzyme and fractionated with CHROMA APIN-400 column. The fractionated cDNA fragments to be longer than 0. 5 kb were ligated into lambda ZAP express vector to form the phagemid cDNA recombinants, which were further packaged into the lambda ZAP cDNA library according to the standard protocol with phage lambda Gold packaging extract. In order to get more stable clones with larger quantity, the primary library was amplified through infecting the host strain XL1-Blue MRF'. Then, the library titre, recombinant rate and length of inserted cDNA were measured, respectively. The capacity of the primary stand or unamplified library was 1. 2X 10(6) pfu. The titers of the unamplified library or the amplified library was 1.1 X 10(6) mixture, pfu/mL or 7. 7 X 10(9) pfu/mL respectively, the percentages of recombinants were 99. 3% and 98. 2%, and the average lengths of the inserts were 2.0 kb and 2. 3 kb, respectively. An excellent cDNA expression library has been constructed successfully, which would lay solid foundation for transplantation study and pre-clinic evaluation of related drugs.

  6. [cDNA libraries construction and screening in gene expression profiling of disease resistance in wheat].

    Science.gov (United States)

    Luo, Meng; Kong, Xiu-Ying; Liu, Yue; Zhou, Rong-Hua; Jia, Ji-Zeng

    2002-09-01

    A wheat line, Bai Nong 3217/Mardler BC5F4 with resistance to powdery mildew, was used to construct a conventional cDNA library and a suppression subtractive hybridization (SSH) cDNA library from wheat leaves inoculated by Erysiphe graminis DC. Three hundred and eighty-seven non-redundant ESTs from the conventional cDNA library and 760 ESTs from the SSH cDNA library were obtained, and the ESTs similarity analysis using BLASTn and BLASTx were conducted by comparing these ESTs with sequences in GenBank. The results showed that the redundancy of some kinds of genes such as photosynthesis related genes and ribosome related genes was higher in the conventional cDNA library but the varieties and quantities of disease resistance genes were less than those in the SSH cDNA library. The SSH cDNA library was found to have obvious advantages in gene expression profiling of disease resistance such as simple library construction procedure, rich specific DRR (disease-resistance-related) genes and decreased sequencing amount. To acquire genes that were involved in the powdery mildew resistance of wheat, hybridization with high-density dots membranes was used to screen the two libraries. The result showed that the method was relatively simple in operation, and the membranes could be used for many times. But some problems also existed with this screening method. For instance, a large amount of mRNA and radioactive isotope were needed and the hybridization procedure must be repeated several times to obtain stable hybridization results. About 54.1% function-known ESTs in the SSH cDNA library were identified to be DRR genes by screening. There were 247 clones of the SSH cDNA library that had positive signal in the repeated hybridizations with the pathogen uninfected probe. The identified DRR genes distributed in the whole procedure of powdery mildew resistance, but mainly focused on the SAR (systemic of acquired resistance).

  7. Isolation of cDNA clones coding for human tissue factor: primary structure of the protein and cDNA

    International Nuclear Information System (INIS)

    Spicer, E.K.; Horton, R.; Bloem, L.

    1987-01-01

    Tissue factor is a membrane-bound procoagulant protein that activates the extrinsic pathway of blood coagulation in the presence of factor VII and calcium. λ Phage containing the tissue factor gene were isolated from a human placental cDNA library. The amino acid sequence deduced from the nucleotide sequence of the cDNAs indicates that tissue factor is synthesized as a higher molecular weight precursor with a leader sequence of 32 amino acids, while the mature protein is a single polypeptide chain composed of 263 residues. The derived primary structure of tissue factor has been confirmed by comparison to protein and peptide sequence data. The sequence of the mature protein suggests that there are three distinct domains: extracellular, residues 1-219; hydrophobic, residues 220-242; and cytoplasmic, residues 243-263. Three potential N-linked carbohydrate attachment sites occur in the extracellular domain. The amino acid sequence of tissue factor shows no significant homology with the vitamin K-dependent serine proteases, coagulation cofactors, or any other protein in the National Biomedical Research Foundation sequence data bank (Washington, DC)

  8. Hot Spot Removal System: System description

    International Nuclear Information System (INIS)

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

  9. Cloning of human purine-nucleoside phosphorylase cDNA sequences by complementation in Escherichia coli.

    OpenAIRE

    Goddard, J M; Caput, D; Williams, S R; Martin, D W

    1983-01-01

    We have obtained cDNA clones that contain the entire coding region of the human purine-nucleoside phosphorylase (PNP; EC 2.4.2.1) mRNA. The cDNA sequences were generated by reverse transcription of PNP-enriched mRNA obtained by immunoadsorption of HeLa cell polyribosomes with monospecific antibody to human PNP. cDNA molecules that were close in length to PNP mRNA were separated by agarose gel electrophoresis and inserted into the Pst I site of the plasmid pBR322. Plasmid DNA from the pooled c...

  10. Generation of cDNA expression libraries enriched for in-frame sequences

    OpenAIRE

    Davis, Claytus A.; Benzer, Seymour

    1997-01-01

    Bacterial cDNA expression libraries are made to reproduce protein sequences present in the mRNA source tissue. However, there is no control over which frame of the cDNA is translated, because translation of the cDNA must be initiated on vector sequence. In a library of nondirectionally cloned cDNAs, only some 8% of the protein sequences produced are expected to be correct. Directional cloning can increase this by a factor of two, but it does not solve the frame problem. We have therefore deve...

  11. Generation of full-length cDNA libraries: focus on plants.

    Science.gov (United States)

    Seki, Motoaki; Kamiya, Asako; Carninci, Piero; Hayashizaki, Yoshihide; Shinozaki, Kazuo

    2009-01-01

    Full-length cDNAs are essential for the correct annotation of transcriptional units and gene products from genomic sequence data and for functional analysis of the genes. Full-length cDNA libraries are very important resources for isolation of the full-length cDNAs. The biotinylated cap trapper method using the trehalose-thermostabilized reverse transcriptase has been developed and has become an efficient method for construction of high-content full-length cDNA libraries. We have constructed full-length cDNA libraries from various plants and animals using this method. The protocol of the method is described in this chapter.

  12. Cloning and sequencing of dolphinfish (Coryphaena hippurus, Coryphaenidae) growth hormone-encoding cDNA.

    Science.gov (United States)

    Peduel, A D; Elizur, A; Knibb, W

    1994-01-01

    The cDNA encoding the preprotein growth hormone from the dolphinfish (Coryphaena hippurus) has been cloned and sequenced. The cDNA was derived by reverse transcription of RNA from the pituitary of a young fish using the method known as Rapid Amplification of cDNA Ends (RACE). An oligonucleotide primer corresponding to the 5' region of Pagrus major and the universal RACE primer enabled amplification using the Polymerase Chain Reaction (PCR). The dolphinfish and yellow-tail, Seriola quineqeradiata, are both members of the sub-order Percoidei (Perciforme) and their GH sequences show a high level of homology.

  13. Chaperone network composition in Solanum lycopersicum explored by transcriptome profiling and microarray meta-analysis.

    Science.gov (United States)

    Fragkostefanakis, Sotirios; Simm, Stefan; Paul, Puneet; Bublak, Daniela; Scharf, Klaus-Dieter; Schleiff, Enrico

    2015-04-01

    Heat shock proteins (Hsps) are molecular chaperones primarily involved in maintenance of protein homeostasis. Their function has been best characterized in heat stress (HS) response during which Hsps are transcriptionally controlled by HS transcription factors (Hsfs). The role of Hsfs and Hsps in HS response in tomato was initially examined by transcriptome analysis using the massive analysis of cDNA ends (MACE) method. Approximately 9.6% of all genes expressed in leaves are enhanced in response to HS, including a subset of Hsfs and Hsps. The underlying Hsp-Hsf networks with potential functions in stress responses or developmental processes were further explored by meta-analysis of existing microarray datasets. We identified clusters with differential transcript profiles with respect to abiotic stresses, plant organs and developmental stages. The composition of two clusters points towards two major chaperone networks. One cluster consisted of constitutively expressed plastidial chaperones and other genes involved in chloroplast protein homeostasis. The second cluster represents genes strongly induced by heat, drought and salinity stress, including HsfA2 and many stress-inducible chaperones, but also potential targets of HsfA2 not related to protein homeostasis. This observation attributes a central regulatory role to HsfA2 in controlling different aspects of abiotic stress response and tolerance in tomato. © 2014 John Wiley & Sons Ltd.

  14. Protective Effect of Gwakhyangjeonggisan Herbal Acupuncture Solution in Glioblastoma Cells: Microarray Analysis of Gene Expression

    Directory of Open Access Journals (Sweden)

    Hong-Seok Lee

    2005-12-01

    Full Text Available Objectives : Neurological disorders have been one of main therapeutic targets of acupuncture. The present study investigated the protective effects of Gwakhyangjeonggisan herbal acupuncture solution (GHAS. Methods : We performed 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay in glioblastoma cells, and did microarray analysis with cells exposed to reactive oxigen species (ROS of hydrogen peroxide by 8.0 k Human cDNA, with cut-off level of 2-fold changes in gene expression. Results : MTT assay showed protective effect of GHAS on the glioblastoma cells exposed to hydrogen peroxide. When glioblastoma cells were exposed to hydrogen peroxide, 24 genes were downregulated. When the cells were pretreated with GHAS before exposure to hydrogen peroxide, 46 genes were downregulated. Many of the genes downregulated by hydrogen peroxide stimulation were decreased in the amount of downregulation or reversed to upregulation. Conclusions : The gene expression changes observed in the present study are supposed to be related to the protective molecular mechanism of GHAS in the glioblastoma cells exposed to ROS stress.

  15. Microarray analysis of differential gene expression elicited in Trametes versicolor during interspecific mycelial interactions.

    Science.gov (United States)

    Eyre, Catherine; Muftah, Wafa; Hiscox, Jennifer; Hunt, Julie; Kille, Peter; Boddy, Lynne; Rogers, Hilary J

    2010-08-01

    Trametes versicolor is an important white rot fungus of both industrial and ecological interest. Saprotrophic basidiomycetes are the major decomposition agents in woodland ecosystems, and rarely form monospecific populations, therefore interspecific mycelial interactions continually occur. Interactions have different outcomes including replacement of one species by the other or deadlock. We have made subtractive cDNA libraries to enrich for genes that are expressed when T. versicolor interacts with another saprotrophic basidiomycete, Stereum gausapatum, an interaction that results in the replacement of the latter. Expressed sequence tags (ESTs) (1920) were used for microarray analysis, and their expression compared during interaction with three different fungi: S. gausapatum (replaced by T. versicolor), Bjerkandera adusta (deadlock) and Hypholoma fasciculare (replaced T. versicolor). Expression of significantly more probes changed in the interaction between T. versicolor and S. gausapatum or B. adusta compared to H. fasciculare, suggesting a relationship between interaction outcome and changes in gene expression. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  16. Microarray analysis reveals genetic pathways modulated by tipifarnib in acute myeloid leukemia

    International Nuclear Information System (INIS)

    Raponi, Mitch; Belly, Robert T; Karp, Judith E; Lancet, Jeffrey E; Atkins, David; Wang, Yixin

    2004-01-01

    Farnesyl protein transferase inhibitors (FTIs) were originally developed to inhibit oncogenic ras, however it is now clear that there are several other potential targets for this drug class. The FTI tipifarnib (ZARNESTRA™, R115777) has recently demonstrated clinical responses in adults with refractory and relapsed acute leukemias. This study was conducted to identify genetic markers and pathways that are regulated by tipifarnib in acute myeloid leukemia (AML). Tipifarnib-mediated gene expression changes in 3 AML cell lines and bone marrow samples from two patients with AML were analyzed on a cDNA microarray containing approximately 7000 human genes. Pathways associated with these expression changes were identified using the Ingenuity Pathway Analysis tool. The expression analysis identified a common set of genes that were regulated by tipifarnib in three leukemic cell lines and in leukemic blast cells isolated from two patients who had been treated with tipifarnib. Association of modulated genes with biological functional groups identified several pathways affected by tipifarnib including cell signaling, cytoskeletal organization, immunity, and apoptosis. Gene expression changes were verified in a subset of genes using real time RT-PCR. Additionally, regulation of apoptotic genes was found to correlate with increased Annexin V staining in the THP-1 cell line but not in the HL-60 cell line. The genetic networks derived from these studies illuminate some of the biological pathways affected by FTI treatment while providing a proof of principle for identifying candidate genes that might be used as surrogate biomarkers of drug activity

  17. Transcriptome sequencing and development of an expression microarray platform for the domestic ferret

    Directory of Open Access Journals (Sweden)

    McBrayer Alexis

    2010-04-01

    Full Text Available Abstract Background The ferret (Mustela putorius furo represents an attractive animal model for the study of respiratory diseases, including influenza. Despite its importance for biomedical research, the number of reagents for molecular and immunological analysis is restricted. We present here a parallel sequencing effort to produce an extensive EST (expressed sequence tags dataset derived from a normalized ferret cDNA library made from mRNA from ferret blood, liver, lung, spleen and brain. Results We produced more than 500000 sequence reads that were assembled into 16000 partial ferret genes. These genes were combined with the available ferret sequences in the GenBank to develop a ferret specific microarray platform. Using this array, we detected tissue specific expression patterns which were confirmed by quantitative real time PCR assays. We also present a set of 41 ferret genes with even transcription profiles across the tested tissues, indicating their usefulness as housekeeping genes. Conclusion The tools developed in this study allow for functional genomic analysis and make further development of reagents for the ferret model possible.

  18. Cytokeratin Profiles Identify Diagnostic Signatures in Colorectal Cancer Using Multiplex Analysis of Tissue Microarrays

    Directory of Open Access Journals (Sweden)

    Thomas Knösel

    2006-01-01

    Full Text Available Background and aims: Recent cDNA expression profiling analyses indicate that within specific organ cancers Cytokeratins (CKs dysregulation may identify subgroups with distinct biological phenotypes. Our objectives in this study were (1 to test whether cytokeratins were also distinct on the protein level, (2 to evaluate these biomarkers in a series of well-characterised CRCs, (3 to apply hierarchical cluster analysis to immunohistochemical data. Methods: Tissue microarrays (TMA comprising 468 CRC specimens from 203 patients were constructed to evaluate CK5, CK7, CK8, CK13, CK14, CK16, CK17, CK18, CK19 and CK20. In total, 2919 samples were analyzed. Results: Unsupervised hierarchical clustering discovered subgroups represented by reduced CK8 and CK20 expression, that differed by a shorter patients survival. The evaluation of the specific biomarkers by Kaplan–Meier analysis showed that reduced CK8 expression (p < 0.01 was significantly associated with shorter patients’ survival, but was not an independent factor correlated with tumour stage (pT, grading (G and nodal stage (pN. Conclusions: Reduced coexpression of CK8 and CK20 may indicate an epithelial-mesenchymal transition (EMT representing an important step in the development of more aggressive CRCs. In addition, multiplex analysis of TMAs together with immunohistochemistry (IHC supplemented by hierarchical clustering are a useful, promising and very powerful tool for the identification of tumour subgroups with diagnostic and prognostic signatures.

  19. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color. ...

  20. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color. ...

  1. 7 CFR 28.413 - Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color. ...

  2. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color. ...

  3. 5'-end sequences of budding yeast full-length cDNA clones and quality scores - Budding yeast cDNA sequencing project | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Budding yeast cDNA sequencing project 5'-end sequences of budding yeast full-length cDNA clones and quality... scores Data detail Data name 5'-end sequences of budding yeast full-length cDNA clones and quality...or-capping method, the sequence quality score generated by the Phred software, and links to SGD, dbEST and U...es. FASTA format. Quality Phred's quality score About This Database Database Desc...g yeast full-length cDNA clones and quality scores - Budding yeast cDNA sequencing project | LSDB Archive ...

  4. Protein microarray-mediated detection of antienterovirus antibodies in serum.

    Science.gov (United States)

    Zhang, Aiying; Xiu, Bingshui; Zhang, Heqiu; Li, Ning

    2016-04-01

    To utilize prokaryotic gene expression and protein microarray to develop and evaluate a sensitive, accurate protein microarray assay for detecting antienterovirus antibodies in serum samples from patients with hand, foot and mouth disease (HFMD). Enterovirus 71 (EV71) and coxsackievirus A16 (CA16), two common causative agents for HFMD, were used for assay development. Serum was collected from patients with HFMD and healthy controls. EV71 and CA16 VP1 and VP3 genes were expressed in transfected Escherichia coli; the resultant VP1 and 3 proteins were used in a microarray assay for human serum EV71 and CA16 immunoglobulin (Ig) M and IgG. To validate the microarray assay, serum samples were tested for EV71 IgM using enzyme-linked immunosorbent assay (ELISA). Out of 50 patients with HFMD, EV71 IgM and CA16 IgM was detected in 80% and 44% of serum samples, respectively, using protein microarray, and EV71 IgM was detected in 78% of samples using ELISA. Protein microarray and ELISA showed 100% specificity for EV71-IgM detection. The protein microarray assay developed in the present study shows potential as a sensitive technique for detecting EV71 IgM in serum samples from patients with HFMD. © The Author(s) 2016.

  5. A Human Lectin Microarray for Sperm Surface Glycosylation Analysis *

    Science.gov (United States)

    Sun, Yangyang; Cheng, Li; Gu, Yihua; Xin, Aijie; Wu, Bin; Zhou, Shumin; Guo, Shujuan; Liu, Yin; Diao, Hua; Shi, Huijuan; Wang, Guangyu; Tao, Sheng-ce

    2016-01-01

    Glycosylation is one of the most abundant and functionally important protein post-translational modifications. As such, technology for efficient glycosylation analysis is in high demand. Lectin microarrays are a powerful tool for such investigations and have been successfully applied for a variety of glycobiological studies. However, most of the current lectin microarrays are primarily constructed from plant lectins, which are not well suited for studies of human glycosylation because of the extreme complexity of human glycans. Herein, we constructed a human lectin microarray with 60 human lectin and lectin-like proteins. All of the lectins and lectin-like proteins were purified from yeast, and most showed binding to human glycans. To demonstrate the applicability of the human lectin microarray, human sperm were probed on the microarray and strong bindings were observed for several lectins, including galectin-1, 7, 8, GalNAc-T6, and ERGIC-53 (LMAN1). These bindings were validated by flow cytometry and fluorescence immunostaining. Further, mass spectrometry analysis showed that galectin-1 binds several membrane-associated proteins including heat shock protein 90. Finally, functional assays showed that binding of galectin-8 could significantly enhance the acrosome reaction within human sperms. To our knowledge, this is the first construction of a human lectin microarray, and we anticipate it will find wide use for a range of human or mammalian studies, alone or in combination with plant lectin microarrays. PMID:27364157

  6. Towards standardization of microarray-based genotyping of Salmonella

    DEFF Research Database (Denmark)

    Löfström, Charlotta; Grønlund, Hugo Ahlm; Riber, Leise

    2010-01-01

    Genotyping is becoming an increasingly important tool to improve risk assessments of Salmonella. DNA microarray technology is a promising diagnostic tool that can provide high resolution genomic profile of many genes simultaneously. However, standardization of DNA microarray analysis is needed...... of Salmonella at two different laboratories. The low-density array contained 281 of 57-60-mer oligonucleotide probes for detecting a wide range of specific genomic markers associated with antibiotic resistance, cell envelope structures, mobile genetic elements and pathogenicity. Several test parameters...... for a decentralized and simple-to-implement DNA microarray as part of a pan-European source-attribution model for risk assessment of Salmonella....

  7. AFM 4.0: a toolbox for DNA microarray analysis.

    Science.gov (United States)

    Breitkreutz, B J; Jorgensen, P; Breitkreutz, A; Tyers, M

    2001-01-01

    We have developed a series of programs, collectively packaged as Array File Maker 4.0 (AFM), that manipulate and manage DNA microarray data. AFM 4.0 is simple to use, applicable to any organism or microarray, and operates within the familiar confines of Microsoft Excel. Given a database of expression ratios, AFM 4.0 generates input files for clustering, helps prepare colored figures and Venn diagrams, and can uncover aneuploidy in yeast microarray data. AFM 4.0 should be especially useful to laboratories that do not have access to specialized commercial or in-house software.

  8. Mouse tetranectin: cDNA sequence, tissue-specific expression, and chromosomal mapping

    DEFF Research Database (Denmark)

    Ibaraki, K; Kozak, C A; Wewer, U M

    1995-01-01

    regulation, mouse tetranectin cDNA was cloned from a 16-day-old mouse embryo library. Sequence analysis revealed a 992-bp cDNA with an open reading frame of 606 bp, which is identical in length to the human tetranectin cDNA. The deduced amino acid sequence showed high homology to the human cDNA with 76...... in human. Although additional minor bands of 1.5 and 3.3 kb were found in Northern blots, RT-PCR (reverse transcription polymerase chain reaction) analysis failed to provide evidence that these minor bands are products of the tetranectin gene. Finally, the genetic map location for this gene, Tna...

  9. Cloning and sequencing of complete τ-crystallin cDNA from ...

    Indian Academy of Sciences (India)

    Unknown

    length τ-crystallin cDNA from crocodilian lens and α-enolase from other tissues. ... human (Acc. No. NM_001428). The sequences were used to construct a phylogenetic tree depicting gene lineage, using the clustering program DNAML.

  10. Construction and characterization of a cDNA expression library from the endangered Hu sheep.

    Science.gov (United States)

    Hu, P-F; Li, X-C; Liu, H-K; Guan, W-J; Ma, Y-H

    2014-10-31

    Hu sheep is one of the most important species in China; it is also listed as one of the 78 nationally protected domestic animals by the Chinese government in 2000. The construction of cDNA expression library of Hu sheep is of great significance for protecting individual genomes, generating transgenic sheep, and conducting clinical research using cDNA from Hu sheep. In this study, the total RNA from the ear tissue of Hu sheep was extracted, and a cDNA expression library was constructed using the SMART(TM) technique. The titer of amplified cDNA library was 1.09 x 10(10) PFU/mL, the rate of recombination was above 91.6%, and the average size of fragments was 1.1 kb. This study has an important significance for the preservation of Hu sheep resources at the genome level.

  11. Mouse tetranectin: cDNA sequence, tissue-specific expression, and chromosomal mapping

    DEFF Research Database (Denmark)

    Ibaraki, K; Kozak, C A; Wewer, U M

    1995-01-01

    regulation, mouse tetranectin cDNA was cloned from a 16-day-old mouse embryo library. Sequence analysis revealed a 992-bp cDNA with an open reading frame of 606 bp, which is identical in length to the human tetranectin cDNA. The deduced amino acid sequence showed high homology to the human cDNA with 76......(s) of tetranectin. The sequence analysis revealed a difference in both sequence and size of the noncoding regions between mouse and human cDNAs. Northern analysis of the various tissues from mouse, rat, and cow showed the major transcript(s) to be approximately 1 kb, which is similar in size to that observed...

  12. cDNA - ASTRA | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available ing/transcriptional initiation regionss About This Database Database Description Download License Update History of This Database Site Policy | Contact Us cDNA - ASTRA | LSDB Archive ...

  13. Transcriptomic identification of candidate genes involved in sunflower responses to chilling and salt stresses based on cDNA microarray analysis

    OpenAIRE

    Paniego Norma; Hopp H Esteban; Fernandez Luis; Di Rienzo Julio; Fernandez Paula; Heinz Ruth A

    2008-01-01

    Abstract Background Considering that sunflower production is expanding to arid regions, tolerance to abiotic stresses as drought, low temperatures and salinity arises as one of the main constrains nowadays. Differential organ-specific sunflower ESTs (expressed sequence tags) were previously generated by a subtractive hybridization method that included a considerable number of putative abiotic stress associated sequences. The objective of this work is to analyze concerted gene expression profi...

  14. Identificação de marcadores moleculares para o câncer de tireóide por cDNA microarrays

    OpenAIRE

    Beatriz Simonsen Stolf

    2003-01-01

    Doenças tireoideanas são bastante comuns, sendo sua maioria benigna. A relação entre os diversos tipos de doenças tireoideanas, bem como seus aspectos moleculares, são pouco conhecidos. O bócio (hiperplasia), por exemplo, é descrito por alguns como relacionado com carcinoma (tumor maligno) papilífero, enquanto que outros afirmam não haver relação causal entre as duas doenças. A questão mais desafiante, porém, refere-se à distinção entre adenoma (tumor benigno) e carcinoma folicular, que atual...

  15. Construction of primary and subtracted cDNA libraries from early embryos.

    Science.gov (United States)

    Rothstein, J L; Johnson, D; Jessee, J; Skowronski, J; DeLoia, J A; Solter, D; Knowles, B B

    1993-01-01

    By modifying current cDNA cloning and electroporation methods, large and representative murine cDNA libraries were synthesized from 10 to 100 ng mRNA isolated from unfertilized egg and preimplantation mouse embryos. High cloning efficiency is essential for complete representation of genes expressed in egg and preimplantation embryos and for the isolation of stage-specific genes using subtractive hybridization. Because the mouse embryo contains no more than 50 pg of poly(A)+ mRNA at any stage of preimplantation development, approximately 5000-10,000 embryos are required to obtain enough mRNA to synthesize libraries using current methods. To obtain a representative library that also includes rare transcripts, the size of the library should be at least 10(6) clones. The average percent conversion of mRNA to single-stranded cDNA was 20-40%, so that a cloning efficiency of nearly 2 x 10(8) cfu/microgram cDNA is required for such a cDNA library. No previous methods have provided directional cloning of cDNA into plasmids with these high efficiencies. The advent of electroporation methods for the introduction of nucleic acids into bacteria has made possible the use of standard plasmid vectors for high-efficiency cDNA cloning. Plasmid vectors are currently available that can accommodate the directional cloning of cDNA such that T7 and T3 RNA polymerase promoter sequences can be used to generate sense and anti-sense transcripts for subtractive hybridization and riboprobe synthesis. The cDNA libraries we derived using this methodology are a reusable and abundant source of genetic information about the control of preimplantation development. Specialized subtractive cDNA libraries enriched for genes expressed exclusively at a predetermined time in development give access to genes expressed in a stage-specific manner. The ability to construct new cDNA libraries from limited amounts of starting material ensures the provision of new and important resources for the identification

  16. Tissue Microarray Analysis Applied to Bone Diagenesis.

    Science.gov (United States)

    Mello, Rafael Barrios; Silva, Maria Regina Regis; Alves, Maria Teresa Seixas; Evison, Martin Paul; Guimarães, Marco Aurelio; Francisco, Rafaella Arrabaca; Astolphi, Rafael Dias; Iwamura, Edna Sadayo Miazato

    2017-01-04

    Taphonomic processes affecting bone post mortem are important in forensic, archaeological and palaeontological investigations. In this study, the application of tissue microarray (TMA) analysis to a sample of femoral bone specimens from 20 exhumed individuals of known period of burial and age at death is described. TMA allows multiplexing of subsamples, permitting standardized comparative analysis of adjacent sections in 3-D and of representative cross-sections of a large number of specimens. Standard hematoxylin and eosin, periodic acid-Schiff and silver methenamine, and picrosirius red staining, and CD31 and CD34 immunohistochemistry were applied to TMA sections. Osteocyte and osteocyte lacuna counts, percent bone matrix loss, and fungal spheroid element counts could be measured and collagen fibre bundles observed in all specimens. Decalcification with 7% nitric acid proceeded more rapidly than with 0.5 M EDTA and may offer better preservation of histological and cellular structure. No endothelial cells could be detected using CD31 and CD34 immunohistochemistry. Correlation between osteocytes per lacuna and age at death may reflect reported age-related responses to microdamage. Methodological limitations and caveats, and results of the TMA analysis of post mortem diagenesis in bone are discussed, and implications for DNA survival and recovery considered.

  17. Tissue microarray profiling in human heart failure.

    Science.gov (United States)

    Lal, Sean; Nguyen, Lisa; Tezone, Rhenan; Ponten, Fredrik; Odeberg, Jacob; Li, Amy; Dos Remedios, Cristobal

    2016-09-01

    Tissue MicroArrays (TMAs) are a versatile tool for high-throughput protein screening, allowing qualitative analysis of a large number of samples on a single slide. We have developed a customizable TMA system that uniquely utilizes cryopreserved human cardiac samples from both heart failure and donor patients to produce formalin-fixed paraffin-embedded sections. Confirmatory upstream or downstream molecular studies can then be performed on the same (biobanked) cryopreserved tissue. In a pilot study, we applied our TMAs to screen for the expression of four-and-a-half LIM-domain 2 (FHL2), a member of the four-and-a-half LIM family. This protein has been implicated in the pathogenesis of heart failure in a variety of animal models. While FHL2 is abundant in the heart, not much is known about its expression in human heart failure. For this purpose, we generated an affinity-purified rabbit polyclonal anti-human FHL2 antibody. Our TMAs allowed high-throughput profiling of FHL2 protein using qualitative and semiquantitative immunohistochemistry that proved complementary to Western blot analysis. We demonstrated a significant relative reduction in FHL2 protein expression across different forms of human heart failure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Transcriptome analysis of zebrafish embryogenesis using microarrays.

    Directory of Open Access Journals (Sweden)

    Sinnakaruppan Mathavan

    2005-08-01

    Full Text Available Zebrafish (Danio rerio is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition, a time point earlier than when the zygotic genome was traditionally thought to become active. Here we provide, for the first time to our knowledge, a comprehensive list of developmentally regulated zebrafish genes and their expression profiles during embryogenesis, including novel information on the temporal expression of several thousand previously uncharacterized genes. The expression data generated from this study are accessible to all interested scientists from our institute resource database (http://giscompute.gis.a-star.edu.sg/~govind/zebrafish/data_download.html.

  19. [Primary culture of cat intestinal epithelial cell and construction of its cDNA library].

    Science.gov (United States)

    Ye, L; Gui-Hua, Z; Kun, Y; Hong-Fa, W; Ting, X; Gong-Zhen, L; Wei-Xia, Z; Yong, C

    2017-04-12

    Objective To establish the primary cat intestinal epithelial cells (IECs) culture methods and construct the cDNA library for the following yeast two-hybrid experiment, so as to screen the virulence interaction factors among the final host. Methods The primary cat IECs were cultured by the tissue cultivation and combined digestion with collagenase XI and dispase I separately. Then the cat IECs cultured was identified with the morphological observation and cyto-keratin detection, by using goat anti-cyto-keratin monoclonal antibodies. The mRNA of cat IECs was isolated and used as the template to synthesize the first strand cDNA by SMART™ technology, and then the double-strand cDNAs were acquired by LD-PCR, which were subsequently cloned into the plasmid PGADT7-Rec to construct yeast two-hybrid cDNA library in the yeast strain Y187 by homologous recombination. Matchmaker™ Insert Check PCR was used to detect the size distribution of cDNA fragments after the capacity calculation of the cDNA library. Results The comparison of the two cultivation methods indicated that the combined digestion of collagenase XI and dispase I was more effective than the tissue cultivation. The cat IECs system of continuous culture was established and the cat IECs with high purity were harvested for constructing the yeast two-hybrid cDNA library. The library contained 1.1×10 6 independent clones. The titer was 2.8×10 9 cfu/ml. The size of inserted fragments was among 0.5-2.0 kb. Conclusion The yeast two-hybrid cDNA library of cat IECs meets the requirements of further screen research, and this study lays the foundation of screening the Toxoplasma gondii virulence interaction factors among the cDNA libraries of its final hosts.

  20. cDNA fingerprinting of osteoprogenitor cells to isolate differentiation stage-specific genes.

    OpenAIRE

    Candeliere, G A; Rao, Y; Floh, A; Sandler, S D; Aubin, J E

    1999-01-01

    A cDNA fingerprinting strategy was developed to identify genes based on their differential expression pattern during osteoblast development. Preliminary biological and molecular staging of cDNA pools prepared by global amplification PCR allowed discrim-inating choices to be made in selection of expressed sequence tags (ESTs) to be isolated. Sequencing of selected ESTs confirmed that both known and novel genes can be isolated from any developmental stage of interest, e.g. from primitive progen...

  1. Construction and characteristics of 3-end enriched cDNA library from individual embryos of cattle.

    Science.gov (United States)

    Long, Jian-Er; He, Li-Qiang; Cai, Xia; Ren, Zhao-Rui; Huang, Shu-Zhen; Zeng, Yi-Tao

    2006-11-01

    To analyze stage-specific gene expression profiles of pre-implantation embryos and evaluate potential viability, techniques were adapted to generate 3-end enriched cDNA libraries from individual embryos of cattle based on RT-PCR methodology. The reproducibility of constructing a cDNA library was tested by five independent PCR experiments with specific primers for the presence of several rare genes such as DNMT1 (DNA methylation transferase 1), DNMT2, DNMT3A, Oct-4/3 (octmer-binding transcription factor), IFN-iota, IGF-2r (insulin like growth factor 2 receptor), and the housekeeping genes, H2A and beta-actin. Results indicated repeatability and that a proportion of expressed genes in the cDNA library from an individual embryo was not affected by limited PCR amplification. From the cDNA library, 134 clones were randomly selected for sequencing and showed that structure related elements accounted for 33.5% of transcripts and the energy- and metabolism-related genes were also an important component being 11.9% in the cDNA library. Approximately 14% of genes in the library were functionally unknown including greater than 5% of genes that were likely novel because there was no identity in Genbank. The frequency of structure-related genes such as beta-actin and ribosomal proteins in the cDNA library corresponded to other reports and suggested that the cDNA library constructed by RT-PCR might be proportional to the mRNA populations. The cDNA libraries constructed from different stage embryos will provide a powerful tool to explore novel genes relevant to embryogenesis, determine the profiling of stage-specific gene expression, and evaluate the potential viability of embryos.

  2. CDNA cloning, characterization and expression of an endosperm-specific barley peroxidase

    DEFF Research Database (Denmark)

    Rasmussen, Søren Kjærsgård; Welinder, K.G.; Hejgaard, J.

    1991-01-01

    A barley peroxidase (BP 1) of pI ca. 8.5 and M(r) 37000 has been purified from mature barley grains. Using antibodies towards peroxidase BP 1, a cDNA clone (pcR7) was isolated from cDNA expression library. The nucleotide sequence of pcR7 gave a derived amino acid sequence identical to the 158 C...

  3. Construction of an infectious cDNA clone of foot-and-mouth disease ...

    Indian Academy of Sciences (India)

    A stable, full-length cDNA clone of FMDV type O1BFS 1860 preceded by a bacteriophage T7 polymerase promoter was assembled in a plasmid vector pGEMR-7Zf(–). An ∼8.2 kb PCR product was amplified from the cDNA clone and a full-length RNA was generated from it by in vitro transcription. Transfection of BHK-21 ...

  4. cDNA cloning and mRNA expression of heat shock protein 70 gene ...

    African Journals Online (AJOL)

    In this study, the full-length heat shock protein 70 of Tegillarca granosa was cloned from cDNA library by rapid amplification of cDNA end (RACE). The open reading frame (ORF) of heat shock protein 70 was 1968 bp, and it encoded a protein of 655 amino acids with a predicted molecular weight of 71.48 kDa and an ...

  5. Cloning of cDNA encoding steroid 11β-hydroxylase (P450c11)

    International Nuclear Information System (INIS)

    Chua, S.C.; Szabo, P.; Vitek, A.; Grzeschik, K.H.; John, M.; White, P.C.

    1987-01-01

    The authors have isolated bovine and human adrenal cDNA clones encoding the adrenal cytochrome P-450 specific for 11β-hydroxylation (P450c11). A bovine adrenal cDNA library constructed in the bacteriophage λ vector gt10 was probed with a previously isolated cDNA clone corresponding to part of the 3' untranslated region of the 4.2-kilobase (kb) mRNA encoding P450c11. Several clones with 3.2-kb cDNA inserts were isolated. Sequence analysis showed that they overlapped the original probe by 300 base pairs (bp). Combined cDNA and RNA sequence data demonstrated a continuous open reading frame of 1509 bases. P450c11 is predicted to contain 479 amino acid residues in the mature protein in addition to a 24-residue amino-terminal mitochondrial signal sequence. A bovine clone was used to isolate a homologous clone with a 3.5-kb insert from a human adrenal cDNA library. A region of 1100 bp was 81% homologous to 769 bp of the coding sequence of the bovine cDNA except for a 400-bp segment presumed to be an unprocessed intron. Hybridization of the human cDNA to DNA from a panel of human-rodent somatic cell hybrid lines and in situ hybridization to metaphase spreads of human chromosomes localized the gene to the middle of the long arm of chromosome 8. These data should be useful in developing reagents for heterozygote detection and prenatal diagnosis of 11β-hydroxylase deficiency, the second most frequent cause of congenital adrenal hyperplasia

  6. Isolation and analysis of genes mainly expressed in adult mouse heart using subtractive hybridization cDNA library.

    Science.gov (United States)

    Komurcu-Bayrak, Evrim; Ozsait, Bilge; Erginel-Unaltuna, Nihan

    2012-08-01

    Subtractive hybridization cDNA library (SHL) is one of the powerful approaches for isolating differentially expressed genes. Using this technique between mouse heart and skeletal muscle (skm) tissues, we aimed to construct a cDNA-library that was specific to heart tissue and to identify the potential candidate genes that might be responsible for the development of cardiac diseases or related pathophysiological conditions. In the first step of the study, we created a cDNA-library between mouse heart and skm tissues. The homologies of the randomly selected 215 clones were analyzed and then classified by function. A total of 146 genes were analyzed for their expression profiles in the heart and skm tissues in published mouse microarray dataset. In the second step, we analyzed the expression patterns of the selected genes by Northern blot and RNA in situ hybridization (RISH). In Northern blot analyses, the expression levels of Myl3, Myl2, Mfn2, Dcn, Pdlim4, mt-Co3, mt-Co1, Atpase6 and Tsc22d1 genes were higher in heart than skm. For first time with this study, expression patterns of Pdlim4 and Tsc22d1 genes in mouse heart and skm were shown by RISH. In the last step, 43 genes in this library were identified to have relationships mostly with cardiac diseases and/or related phenotypes. This is the first study reporting differentially expressed genes in healthy mouse heart using SHL technique. This study confirms our hypothesis that tissue-specific genes are most likely to have a disease association, if they possess mutations.

  7. HUBBLE FINDS NEW DARK SPOT ON NEPTUNE

    Science.gov (United States)

    2002-01-01

    NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet. The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared. Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere. Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere. The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops. Credit: H. Hammel (Massachusetts Institute of Technology) and NASA

  8. Trehalose as a good candidate for enriching full-length cDNAs in cDNA library construction.

    Science.gov (United States)

    Chen, Lei; Cao, Lixue; Zhou, Longhai; Jing, Yudong; Chen, Zuozhou; Deng, Cheng; Shen, Yu; Chen, Liangbiao

    2007-01-10

    It has been reported that the disaccharide trehalose is capable of increasing the thermostability and thermoactivity of reverse transcriptase, and therefore improving the length of cDNA synthesis. However, no test has been done on how the disaccharide trehalose performs in the context of the entire cDNA synthesis processes, or whether it can seamlessly integrate into the commercially available cDNA synthesis kit. In this report, we optimized a protocol to incorporate trehalose in the Stratagene's cDNA library construction kit in order to demonstrate great improvement in cDNA's length (average length of 1.8 kb in the trehalose group versus 1.0 kb in the control). Sequence analysis of the cDNA clones showed that the addition of trehalose did not increase the error rate of the RT products but greatly increase the quantity of full-length in cDNA library.

  9. Construction of Infectious cDNA Clone of a Chrysanthemum stunt viroid Korean Isolate

    Science.gov (United States)

    Yoon, Ju-Yeon; Cho, In-Sook; Choi, Gug-Seoun; Choi, Seung-Kook

    2014-01-01

    Chrysanthemum stunt viroid (CSVd), a noncoding infectious RNA molecule, causes seriously economic losses of chrysanthemum for 3 or 4 years after its first infection. Monomeric cDNA clones of CSVd isolate SK1 (CSVd-SK1) were constructed in the plasmids pGEM-T easy vector and pUC19 vector. Linear positive-sense transcripts synthesized in vitro from the full-length monomeric cDNA clones of CSVd-SK1 could infect systemically tomato seedlings and chrysanthemum plants, suggesting that the linear CSVd RNA transcribed from the cDNA clones could be replicated as efficiently as circular CSVd in host species. However, direct inoculation of plasmid cDNA clones containing full-length monomeric cDNA of CSVd-SK1 failed to infect tomato and chrysanthemum and linear negative-sense transcripts from the plasmid DNAs were not infectious in the two plant species. The cDNA sequences of progeny viroid in systemically infected tomato and chrysanthemum showed a few substitutions at a specific nucleotide position, but there were no deletions and insertions in the sequences of the CSVd progeny from tomato and chrysanthemum plants. PMID:25288987

  10. Construction of a T7 Human Lung Cancer cDNA Library

    Directory of Open Access Journals (Sweden)

    Wentao YUE

    2008-10-01

    Full Text Available Background and objective Currently, only a limited numbers of tumor markers for non small lung cancer (NSCLC diagnosis, new biomarker, such as serum autoantibody may improve the early detection of lung cancer. Our objective is construction human lung squamous carcinoma and adenocarcinoma T7 phage display cDNA library from the tissues of NSCLC patients. Methods mRNA was isolated from a pool of total RNA extract from NSCLC tissues obtained from 5 adenocarcinomas and 5 squamous carcinomas, and then mRNA was reverse transcribed into double stranded cDNA. After digestion, the cDNA was inserted into T7Select 10-3 vector. The phage display cDNA library was constructed by package reaction in vitro and plate proliferation. Plaque assay and PCR were used to evaluate the library.Results Two T7 phage display cDNA library were established. Plaque assay show the titer of lung squamas carcinoma library was 1.8×106 pfu, and the adenocarcinoma library was 5×106 pfu. The phage titer of the amplified library were 3.2×1010 pfu/mL and 2.5×1010 pfu/mL. PCR amplification of random plaque show insert ratio were 100% (24/24 in adenocarcinoma library and 95.8% in human lung squamas carcinoma library (23/24. Insert range from 300 bp to 1 500 bp. Conclusion Two phage display cDNA library from NSCLC were constructed.

  11. [Construction of suppression subtracted cDNA library of deltamethrin-resistant Aedes albopictus].

    Science.gov (United States)

    Wu, Jia-hong; Zhao, Tong-yan; Dong, Yan-de

    2006-08-01

    To construct the suppression subtracted cDNA library of deltamethrin-resistant Aedes albopictus. Total RNA was extracted from the deltamethrin-resistant (R-lab) and -sensitive (S-lab) isolates, mRNA was obtained after purification. Double stranded cDNAs were synthesized after reverse transcription. Two subtractions were performed by suppression subtractive hybridization with S-lab as tester and R-lab as driver or S-lab as driver and R-lab as tester. Enriched different expressed cDNA was cloned into pMD18-T vector to construct subtractive libraries. The subtracted cDNA libraries contained 580 and 477 positive clones respectively. The PCR results of 150 clones picked randomly from each library showed that the positive ratio of constructed cDNA libraries was 93%, with a length of cDNA fragments ranged from 150bp to 750bp. The suppression subtracted cDNA library of deltamethrin-resistant Ae. albopictus is constructed.

  12. [Construction of the subtracted cDNA libraries related to artemisinin-resistance of Plasmodium berghei].

    Science.gov (United States)

    Bei, Zhu-chun; Wang, Jing-yan

    2004-06-01

    To construct the subtracted cDNA libraries related to artemisinin-resistance of Plasmodium berghei using suppression subtractive hybridization PCR (SSH PCR). Total RNA was extracted from the artemisinin-sensitive (NS) and artemisinin-resistant (AR) strains of Plasmodium berghei K173. The cDNA synthesis followed the protocol of super SMART cDNA synthesis kit. Taking the NS as driver, AR as tester and reverse, two subtractions were performed by SSH PCR. Enriched different expressed cDNA was cloned into pMD18-T vector to construct subtractive libraries. The subtracted cDNA libraries of NS-AR and AR-NS contained 395 and 506 positive clones respectively. The PCR results of 108 clones picked randomly from each library showed 100 and 104 positive inserts contained in the plasmids respectively, and distributing in 250-2000 bp. The successful construction of the subtracted cDNA libraries related to artemisinin-resistance of P. berghei enable us to identify the different expressed genes involved in the resistance mechanism.

  13. [cDNA library constructing and specific antigen expression of Streptomyces thermohydroscopicus].

    Science.gov (United States)

    Xu, Lei; Wang, Ling-ling; Liu, Shuo; Ling, Yuan; Ma, Lie; Wang, Qun; Zhang, Li-jiao; He, Xiao-yu; Zhao, Ming-jing; Wang, Xiao-ge

    2012-03-01

    To construct a cDNA library from Streptomyces thermohydroscopicus and screen genes with virulence, obtain the recombinant fusion virulence proteins by prokaryotic expression system. The Streptomyces thermohydroscopicus cDNA library was constructed by switching mechanism at 5'end of RNA transcript approach. A total of 1020 clones randomly selected from the cDNA library were sequenced and these expressed sequence tags (EST) were further analyzed for the screen of antigen-specific genes. The two candidate genes were subcloned into expression vector pET-28a. The recombinants were transformed into BL2 and proteins were expressed by the induction of isopropyl-β-D-1-thiogalactopyranoside (IPTG). A high-quality cDNA library from Streptomyces thermohydroscopicus was constructed and a set of 978 valid sequences were obtained. Clustering and assembly of these cDNA sequences resulted in 347 unique genes, among which 2 potential antigen-specific genes were highly allied with outer membrane lipoprotein (51%) and transferring-binding protein B (42%) from Actinobacillus pleuropneumoniae serotype (APP). The open reading frame (ORF) of the two candidate genes are 1554 bp and 726 bp, which coded two peptides with 517 and 241 amino acids, respectively. The molecular weights of the recombinant fusion proteins were 63 000 and 30 000. The cDNA library of Streptomyces thermohydroscopicus reached the quality requirement of gene library. EST database in the library would greatly facilitate further screening of virulence genes.

  14. Rapid Diagnosis of Bacterial Meningitis Using a Microarray

    Directory of Open Access Journals (Sweden)

    Ren-Jy Ben

    2008-06-01

    Conclusion: The microarray method provides a more accurate and rapid diagnostic tool for bacterial meningitis compared to traditional culture methods. Clinical application of this new technique may reduce the potential risk of delay in treatment.

  15. Identification of mycotoxigenic fungi using an oligonucleotide microarray

    CSIR Research Space (South Africa)

    Barros, E

    2013-01-01

    Full Text Available the development of an oligonucleotide microarray specific for eleven mycotoxigenic fungi isolated from different food commodities in South Africa. This array is suitable for the detection and identification of cultures of potential mycotoxigenic fungi in both...

  16. Novel Protein Microarray Technology to Examine Men with Prostate Cancer

    National Research Council Canada - National Science Library

    Lilja, Hans

    2005-01-01

    The authors developed a novel macro and nanoporous silicon surface for protein microarrays to facilitate high-throughput biomarker discovery, and high-density protein-chip array analyses of complex biological samples...

  17. Kernel Based Nonlinear Dimensionality Reduction and Classification for Genomic Microarray

    Science.gov (United States)

    Li, Xuehua; Shu, Lan

    2008-01-01

    Genomic microarrays are powerful research tools in bioinformatics and modern medicinal research because they enable massively-parallel assays and simultaneous monitoring of thousands of gene expression of biological samples. However, a simple microarray experiment often leads to very high-dimensional data and a huge amount of information, the vast amount of data challenges researchers into extracting the important features and reducing the high dimensionality. In this paper, a nonlinear dimensionality reduction kernel method based locally linear embedding(LLE) is proposed, and fuzzy K-nearest neighbors algorithm which denoises datasets will be introduced as a replacement to the classical LLE's KNN algorithm. In addition, kernel method based support vector machine (SVM) will be used to classify genomic microarray data sets in this paper. We demonstrate the application of the techniques to two published DNA microarray data sets. The experimental results confirm the superiority and high success rates of the presented method. PMID:27879930

  18. Kernel Based Nonlinear Dimensionality Reduction and Classification for Genomic Microarray.

    Science.gov (United States)

    Li, Xuehua; Shu, Lan

    2008-07-15

    Genomic microarrays are powerful research tools in bioinformatics and modern medicinal research because they enable massively-parallel assays and simultaneous monitoring of thousands of gene expression of biological samples. However, a simple microarray experiment often leads to very high-dimensional data and a huge amount of information, the vast amount of data challenges researchers into extracting the important features and reducing the high dimensionality. In this paper, a nonlinear dimensionality reduction kernel method based locally linear embedding(LLE) is proposed, and fuzzy K-nearest neighbors algorithm which denoises datasets will be introduced as a replacement to the classical LLE's KNN algorithm. In addition, kernel method based support vector machine (SVM) will be used to classify genomic microarray data sets in this paper. We demonstrate the application of the techniques to two published DNA microarray data sets. The experimental results confirm the superiority and high success rates of the presented method.

  19. Pink Spot - Literature Review and Case Report.

    Science.gov (United States)

    Petel, Roy; Fuks, Anna

    Pink spots in teeth were first described by Mummery in 1920, and were related to resorption. Resorption is a pathologic process that often eludes the clinician with its varied etiologic factors and diverse clinical presentations. Resorption can be generally classified as internal and external resorption. Internal resorption has been described as a rare occurrence as compared to external resorption. This article describes a pink spot that was diagnosed as a progressing resorption process. Early diagnosis enabled a successful management of the lesion. Early diagnosis and treatment of an internal resorption, clinically seen as a pink spot, in a primary central incisor may prevent its fast progress and subsequent loss.

  20. Characterization of ORF89 - A latency-related gene of white spot syndrome virus

    International Nuclear Information System (INIS)

    Hossain, M.S.; Khadijah, Siti; Kwang, Jimmy

    2004-01-01

    Open reading frame 89 (ORF89) is one of the three genes that are believed to be involved in the latent infection of white spot syndrome virus (WSSV). Here, we report the structure and functional characterization of ORF89. cDNA sequencing, 5' RLM-RACE, and 3' RLM-RACE showed that ORF89 gene is transcribed into an unspliced mRNA of 4436 nucleotides, which is predicted to encode a protein of 1437 amino acids. ORF89 expressed an approximately 165-kDa protein in Sf9 cells that localized in the nucleus. Amino acids 678-683 were found to be essential for nuclear localization. Cotransfection assays demonstrated that ORF89 protein repressed its own promoter as well as those of a protein kinase and the thymidine-thymidylate kinase genes of WSSV. SYBR Green real-time PCR indicated that the repression occurred at the transcriptional level

  1. Profiling In Situ Microbial Community Structure with an Amplification Microarray

    Science.gov (United States)

    Knickerbocker, Christopher; Bryant, Lexi; Golova, Julia; Wiles, Cory; Williams, Kenneth H.; Peacock, Aaron D.; Long, Philip E.

    2013-01-01

    The objectives of this study were to unify amplification, labeling, and microarray hybridization chemistries within a single, closed microfluidic chamber (an amplification microarray) and verify technology performance on a series of groundwater samples from an in situ field experiment designed to compare U(VI) mobility under conditions of various alkalinities (as HCO3−) during stimulated microbial activity accompanying acetate amendment. Analytical limits of detection were between 2 and 200 cell equivalents of purified DNA. Amplification microarray signatures were well correlated with 16S rRNA-targeted quantitative PCR results and hybridization microarray signatures. The succession of the microbial community was evident with and consistent between the two microarray platforms. Amplification microarray analysis of acetate-treated groundwater showed elevated levels of iron-reducing bacteria (Flexibacter, Geobacter, Rhodoferax, and Shewanella) relative to the average background profile, as expected. Identical molecular signatures were evident in the transect treated with acetate plus NaHCO3, but at much lower signal intensities and with a much more rapid decline (to nondetection). Azoarcus, Thaurea, and Methylobacterium were responsive in the acetate-only transect but not in the presence of bicarbonate. Observed differences in microbial community composition or response to bicarbonate amendment likely had an effect on measured rates of U reduction, with higher rates probable in the part of the field experiment that was amended with bicarbonate. The simplification in microarray-based work flow is a significant technological advance toward entirely closed-amplicon microarray-based tests and is generally extensible to any number of environmental monitoring applications. PMID:23160129

  2. Microarray analysis of gene expression during bacteriophage T4 infection.

    Science.gov (United States)

    Luke, Kimberly; Radek, Agnes; Liu, XiuPing; Campbell, John; Uzan, Marc; Haselkorn, Robert; Kogan, Yakov

    2002-08-01

    Genomic microarrays were used to examine the complex temporal program of gene expression exhibited by bacteriophage T4 during the course of development. The microarray data confirm the existence of distinct early, middle, and late transcriptional classes during the bacteriophage replicative cycle. This approach allows assignment of previously uncharacterized genes to specific temporal classes. The genomic expression data verify many promoter assignments and predict the existence of previously unidentified promoters.

  3. Design and analysis of mismatch probes for long oligonucleotide microarrays

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Ye; He, Zhili; Van Nostrand, Joy D.; Zhou, Jizhong

    2008-08-15

    Nonspecific hybridization is currently a major concern with microarray technology. One of most effective approaches to estimating nonspecific hybridizations in oligonucleotide microarrays is the utilization of mismatch probes; however, this approach has not been used for longer oligonucleotide probes. Here, an oligonucleotide microarray was constructed to evaluate and optimize parameters for 50-mer mismatch probe design. A perfect match (PM) and 28 mismatch (MM) probes were designed for each of ten target genes selected from three microorganisms. The microarrays were hybridized with synthesized complementary oligonucleotide targets at different temperatures (e.g., 42, 45 and 50 C). In general, the probes with evenly distributed mismatches were more distinguishable than those with randomly distributed mismatches. MM probes with 3, 4 and 5 mismatched nucleotides were differentiated for 50-mer oligonucleotide probes hybridized at 50, 45 and 42 C, respectively. Based on the experimental data generated from this study, a modified positional dependent nearest neighbor (MPDNN) model was constructed to adjust the thermodynamic parameters of matched and mismatched dimer nucleotides in the microarray environment. The MM probes with four flexible positional mismatches were designed using the newly established MPDNN model and the experimental results demonstrated that the redesigned MM probes could yield more consistent hybridizations. Conclusions: This study provides guidance on the design of MM probes for long oligonucleotides (e.g., 50 mers). The novel MPDNN model has improved the consistency for long MM probes, and this modeling method can potentially be used for the prediction of oligonucleotide microarray hybridizations.

  4. Assessing Bacterial Interactions Using Carbohydrate-Based Microarrays

    Directory of Open Access Journals (Sweden)

    Andrea Flannery

    2015-12-01

    Full Text Available Carbohydrates play a crucial role in host-microorganism interactions and many host glycoconjugates are receptors or co-receptors for microbial binding. Host glycosylation varies with species and location in the body, and this contributes to species specificity and tropism of commensal and pathogenic bacteria. Additionally, bacterial glycosylation is often the first bacterial molecular species encountered and responded to by the host system. Accordingly, characterising and identifying the exact structures involved in these critical interactions is an important priority in deciphering microbial pathogenesis. Carbohydrate-based microarray platforms have been an underused tool for screening bacterial interactions with specific carbohydrate structures, but they are growing in popularity in recent years. In this review, we discuss carbohydrate-based microarrays that have been profiled with whole bacteria, recombinantly expressed adhesins or serum antibodies. Three main types of carbohydrate-based microarray platform are considered; (i conventional carbohydrate or glycan microarrays; (ii whole mucin microarrays; and (iii microarrays constructed from bacterial polysaccharides or their components. Determining the nature of the interactions between bacteria and host can help clarify the molecular mechanisms of carbohydrate-mediated interactions in microbial pathogenesis, infectious disease and host immune response and may lead to new strategies to boost therapeutic treatments.

  5. Transcriptome analysis of Litopenaeus vannamei in response to white spot syndrome virus infection.

    Directory of Open Access Journals (Sweden)

    Xiaohan Chen

    Full Text Available Pacific white shrimp (Litopenaeus vannamei is the most extensively farmed crustacean species in the world. White spot syndrome virus (WSSV is one of the major pathogens in the cultured shrimp. However, the molecular mechanisms of the host-virus interaction remain largely unknown. In this study, the impact of WSSV infection on host gene expression in the hepatopancreas of L. vannamei was investigated through the use of 454 pyrosequencing-based RNA-Seq of cDNA libraries developed from WSSV-challenged shrimp or normal controls. By comparing the two cDNA libraries, we show that 767 host genes are significantly up-regulated and 729 genes are significantly down-regulated by WSSV infection. KEGG analysis of the differentially expressed genes indicated that the distribution of gene pathways between the up- and down-regulated genes is quite different. Among the differentially expressed genes, several are found to be involved in various processes of animal defense against pathogens such as apoptosis, mitogen-activated protein kinase (MAPK signaling, toll-like receptor (TLR signaling, Wnt signaling and antigen processing and presentation pathways. The present study provides valuable information on differential expression of L. vannamei genes following WSSV infection and improves our current understanding of this host-virus interaction. In addition, the large number of transcripts obtained in this study provides a strong basis for future genomic research on shrimp.

  6. Efficacy Testing of H56 cDNA Tattoo Immunization against Tuberculosis in a Mouse Model.

    Science.gov (United States)

    Platteel, Anouk C M; Nieuwenhuizen, Natalie E; Domaszewska, Teresa; Schürer, Stefanie; Zedler, Ulrike; Brinkmann, Volker; Sijts, Alice J A M; Kaufmann, Stefan H E

    2017-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis ( Mtb ), remains a global threat. The only approved vaccine against TB, Mycobacterium bovis bacillus Calmette-Guérin (BCG), provides insufficient protection and, being a live vaccine, can cause disseminated disease in immunocompromised individuals. Previously, we found that intradermal cDNA tattoo immunization with cDNA of tetanus toxoid fragment C domain 1 fused to cDNA of the fusion protein H56, comprising the Mtb antigens Ag85B, ESAT-6, and Rv2660c, induced antigen-specific CD8 + T cell responses in vivo . As cDNA tattoo immunization would be safer than a live vaccine in immunocompromised patients, we tested the protective efficacy of intradermal tattoo immunization against TB with H56 cDNA, as well as with H56_E, a construct optimized for epitope processing in a mouse model. As Mtb antigens can be used in combination with BCG to boost immune responses, we also tested the protective efficacy of heterologous prime-boost, using dermal tattoo immunization with H56_E cDNA to boost BCG immunization in mice. Dermal H56 and H56_E cDNA immunization induced H56-specific CD4 + and CD8 + T cell responses and Ag85B-specific IgG antibodies, but did not reduce bacterial loads, although immunization with H56_E ameliorated lung pathology. Both subcutaneous and intradermal immunization with BCG resulted in broad cellular immune responses, with increased frequencies of CD4 + T effector memory cells, T follicular helper cells, and germinal center B cells, and resulted in reduced bacterial loads and lung pathology. Heterologous vaccination with BCG/H56_E cDNA induced increased H56-specific CD4 + and CD8 + T cell cytokine responses compared to vaccination with BCG alone, and lung pathology was significantly decreased in BCG/H56_E cDNA immunized mice compared to unvaccinated controls. However, bacterial loads were not decreased after heterologous vaccination compared to BCG alone. CD4 + T cells responding to Ag85B- and ESAT-6

  7. Asparagus Beetle and Spotted Asparagus Beetle

    OpenAIRE

    Hodgson, Erin W.; Drost, Dan

    2007-01-01

    Asparagus beetle, Crioceris asparagi, and spotted asparagus beetle, C. duodecimpunctata are leaf beetles in the family Chrysomelidae. These beetles feed exclusively on asparagus and are native to Europe. Asparagus beetle is the more economically injurious of the two species.

  8. Detecting Blind Spot By Using Ultrasonic Sensor

    Directory of Open Access Journals (Sweden)

    T. S. Ajay

    2015-08-01

    Full Text Available Safety remains a top concern for automobile industries and new-car shoppers. Detection of Blind Spots is a major concern for safety issues. So automobiles have been constantly updating their products with new technologies to detect blind spots so that they can add more safety to the vehicle and also reduce the road accidents. Almost 1.5 million people die in road accidents each year. Blind spot of an automobile is the region of the vehicle which cannot be observed properly while looking either through side or rear mirror view. To meet the above requirements this paper describes detecting blind spot by using ultrasonic sensor and controlling the direction of car by automatic steering. The technology embedded in the system is capable of automatically steer the vehicle away from an obstacle if the system determines that a collision is impending or if the vehicle is in the vicinity of our car.

  9. How Many Spots Does a Cheetah Have?

    Science.gov (United States)

    Reed, Kristine M.

    2000-01-01

    Describes first grade students' mathematical investigation of the number of spots on a cheetah. The exploration of counting and estimation strategies that grew from the investigation gives evidence that mathematicians come in all ages. (ASK)

  10. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  11. A telemetry experiment on spotted grunter Pomadasys ...

    African Journals Online (AJOL)

    associated fish in South Africa was investigated by conducting a tracking experiment on spotted grunter Pomadasys commersonnii in the East Kleinemonde Estuary. The telemetry equipment comprised two VEMCO V8 transmitters and a ...

  12. Measuring microfocus focal spots using digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Fry, David A [Los Alamos National Laboratory

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification (especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application); (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. When determining microfocus focal spot dimensions using unsharpness measurements both signal-to-noise (SNR) and magnification can be important. There is a maximum accuracy that is a function of SNR and therefore an optimal magnification. Greater than optimal magnification can be used but it will not increase accuracy.

  13. X-ray spot film device

    International Nuclear Information System (INIS)

    Pury, T.; Tsen, M.L.S.; Gray, F.L.; Stehr, R.E.; Konle, R.L.

    1981-01-01

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  14. Thermal Wave Imaging: Flying SPOT Camera.

    Science.gov (United States)

    Wang, Yiqian

    1993-01-01

    A novel "Flying Spot" infrared camera for nondestructive evaluation (NDE) and nondestructive characterization is presented. The camera scans the focal point of an unmodulated heating laser beam across the sample in a raster. The detector of the camera tracks the heating spot in the same raster, but with a time delay. The detector is thus looking at the "thermal wake" of the heating spot. The time delay between heating and detection is determined by the speed of the laser spot and the distance between it and the detector image. Since this time delay can be made arbitrarily small, the camera is capable of making thermal wave images of phenomena which occur on a very short time scale. In addition, because the heat source is a very small spot, the heat flow is fully three-dimensional. This makes the camera system sensitive to features, like tightly closed vertical cracks, which are invisible to imaging systems which employ full-field heating. A detailed theory which relates the temperature profile around the heating spot to the sample thermal properties is also described. The camera represents a potentially useful tool for measuring thermal diffusivities of materials by means of fitting the recorded temperature profiles to the theoretical curves with the diffusivity as a fitting parameter.

  15. cDNA sequencing improves the detection of P53 missense mutations in colorectal cancer

    International Nuclear Information System (INIS)

    Szybka, Malgorzata; Kordek, Radzislaw; Zakrzewska, Magdalena; Rieske, Piotr; Pasz-Walczak, Grazyna; Kulczycka-Wojdala, Dominika; Zawlik, Izabela; Stawski, Robert; Jesionek-Kupnicka, Dorota; Liberski, Pawel P

    2009-01-01

    Recently published data showed discrepancies beteween P53 cDNA and DNA sequencing in glioblastomas. We hypothesised that similar discrepancies may be observed in other human cancers. To this end, we analyzed 23 colorectal cancers for P53 mutations and gene expression using both DNA and cDNA sequencing, real-time PCR and immunohistochemistry. We found P53 gene mutations in 16 cases (15 missense and 1 nonsense). Two of the 15 cases with missense mutations showed alterations based only on cDNA, and not DNA sequencing. Moreover, in 6 of the 15 cases with a cDNA mutation those mutations were difficult to detect in the DNA sequencing, so the results of DNA analysis alone could be misinterpreted if the cDNA sequencing results had not also been available. In all those 15 cases, we observed a higher ratio of the mutated to the wild type template by cDNA analysis, but not by the DNA analysis. Interestingly, a similar overexpression of P53 mRNA was present in samples with and without P53 mutations. In terms of colorectal cancer, those discrepancies might be explained under three conditions: 1, overexpression of mutated P53 mRNA in cancer cells as compared with normal cells; 2, a higher content of cells without P53 mutation (normal cells and cells showing K-RAS and/or APC but not P53 mutation) in samples presenting P53 mutation; 3, heterozygous or hemizygous mutations of P53 gene. Additionally, for heterozygous mutations unknown mechanism(s) causing selective overproduction of mutated allele should also be considered. Our data offer new clues for studying discrepancy in P53 cDNA and DNA sequencing analysis

  16. [Construction of phage display cDNA library from adult worms of Schistosoma japonicum].

    Science.gov (United States)

    Sun, Yi; Jia, Ren-chu; Liu, Jin-ming; Yuan, Chun-xiu; Shi, Yao-jun; Lu, Ke; Fu, Zhi-qiang; Sun, Huan; Cai, You-min; Lin, Jiao-jiao

    2007-10-01

    To screen protective antigen genes and construct the T7 phage display library from adult worms of Schistosoma japonicum. Total RNA was extracted from adult worms of S. japonicum by Trizol reagent anti mRNA was isolated from the total RNA. The ds cDNA was synthesized by reverse transcription using random primer. Directional EcoR I/ Hind III linkers were ligated into the ends of ds cDNA and the ds cDNA was digested with EcoR I anti Hind III, which resulted in ds cDNA with EcoR I and Hind III adhering ends. The digested ds cDNA fragments longer than 300 bp in length were fractionated and ligated into T7 Select 10-3b vector. After packaging in citro, the T7 Select 10-3b vector was transformed into BLT5403 to construct the T7 phage display cDNA library. Plaque assay and PCR were used to evaluate the library. Seven known objective genes of S. japonicum were screened by PCR to detect the representation of the library. Primary library capacity was 4.98 x 10(6) pfu, and the titer of amplified library was 3.85 x 10(11) pfu/mL. The PCR identification result of 96 clones picked at random showed that recombination rate was 93.8%, in which 95.6% inserted cDNA fragments were longer than 300 bp in length. All the seven known objective genes of S. japonicum were amplified from the library. The T7 phage display library from adult worms of Schistosoma japonicum was constructed.

  17. [Construction of cDNA expression library of unfed female Haemaphysalis longicornis and immuno-screening].

    Science.gov (United States)

    Chai, Hui-ping; Liu, Guang-yuan; Zhang, Lin; Gong, Zhen-li; Xie, Jun-ren; Tian, Zhan-cheng; Wang, Lu; Jia, Ning

    2009-02-28

    To construct a cDNA expression library from unfed female tick Haemaphysalis longicornis for screening and cloning potential antigenic genes. Total RNA was isolated from unfed female ticks, mRNA was purified and a library of oligo (dT) -primed cDNA with added directional EcoR I /Hind III linkers was constructed from the purified mRNA. The constructed cDNA was ligated to the EcoR I /Hind III arms of the lambda SCREEN vector. Pure phage stocks were harvested by plaque purification and converted to plasmid subclones by plating phage on host strain BM25.8. Recombinant plasmids that were subcloned to E. coli BM25.8 were isolated and transformed into E. coli JM109. Recombinant plasmids abstracted from JM109 were identified by PCR and sequencing. The recombinant phage DNA was packaged by using phage-marker packaging extracts, resulting in a primary cDNA library with a size of 1.8 x 10(6) pfu. Data showed 100% of the library were recombinant and the titer of the amplified library was 2.4 x 10(9) pfu/ml. Forty-two clones of encoding immunodominant antigens were obtained from the cDNA library. Sequence analysis revealed 12 unique cDNA sequences and the encoded putative proteins showed similarities to H. longicornis tropomyosin mRNA, Rhipicephalus annulatus unknown larval protein mRNA, chromosome 2R of Drosophila melanogaster, mitochondrial DNA of H. flava, clones HqL09 unkown mRNA and Hq05 mRNA of H. qinghaiensis, and myosin alkali light chain protein mRNA. The cDNA expression library from unfed female H. longicornis was successfully constructed and screening of protective genes may provide candidate antigens of the tick.

  18. Assessing probe-specific dye and slide biases in two-color microarray data

    Directory of Open Access Journals (Sweden)

    Goldberg Zelanna

    2008-07-01

    Full Text Available Abstract Background A primary reason for using two-color microarrays is that the use of two samples labeled with different dyes on the same slide, that bind to probes on the same spot, is supposed to adjust for many factors that introduce noise and errors into the analysis. Most users assume that any differences between the dyes can be adjusted out by standard methods of normalization, so that measures such as log ratios on the same slide are reliable measures of comparative expression. However, even after the normalization, there are still probe specific dye and slide variation among the data. We define a method to quantify the amount of the dye-by-probe and slide-by-probe interaction. This serves as a diagnostic, both visual and numeric, of the existence of probe-specific dye bias. We show how this improved the performance of two-color array analysis for arrays for genomic analysis of biological samples ranging from rice to human tissue. Results We develop a procedure for quantifying the extent of probe-specific dye and slide bias in two-color microarrays. The primary output is a graphical diagnostic of the extent of the bias which called ECDF (Empirical Cumulative Distribution Function, though numerical results are also obtained. Conclusion We show that the dye and slide biases were high for human and rice genomic arrays in two gene expression facilities, even after the standard intensity-based normalization, and describe how this diagnostic allowed the problems causing the probe-specific bias to be addressed, and resulted in important improvements in performance. The R package LMGene which contains the method described in this paper has been available to download from Bioconductor.

  19. Analysis of human HPRT- deletion mutants by the microarray-CGH (comparative genomic hybridization)

    International Nuclear Information System (INIS)

    Kodaira, M.; Sasaki, K.; Tagawa, H.; Omine, H.; Kushiro, J.; Takahashi, N.; Katayama, H.

    2003-01-01

    We are trying to evaluate genetic effects of radiation on human using mutation frequency as an indicator. For the efficient detection of mutations, it is important to understand the mechanism and the characteristics of radiation-induced mutations. We have started the analysis of hypoxanthine-guanine phosphoribosyl transferase (HPRT) mutants induced by X-ray in order to clarify the deletion size and the mutation-distribution. We analyzed 39 human X-ray induced HPRT-deletion mutants by using the microarray-CGH. The array for this analysis contains 57 BAC clones covering as much as possible of the 4Mb of the 5' side and 10Mb of the 3' side of the HPRT gene based on the NCBI genome database. DNA from parent strain and each HPRT-mutant strain are labeled with Cy5 and Cy3 respectively, and were mixed and hybridized on the array. Fluorescent intensity ratio of the obtained spots was analyzed using software we developed to identify clones corresponding to the deletion region. The deletion in these strains ranged up to 3.5 Mb on the 5' side and 6 Mb on the 3' side of the HPRT gene. Deletions in 13 strains ended around BAC clones located at about 3 Mb on the 5' side. On the 3' side, deletions extended up to the specific clones located at 1.5 Mb in 11 strains. The mutations seem to be complex on the 3' end of deletion; some accompanied duplications with deletions and others could not be explained by one mutation event. We need to confirm these results, taking into account the experimental reproducibility and the accuracy of the published genetic map. The results of the research using the microarray-CGH help us to search the regions where deletions are easily induced and to identify the factors affecting the range of deletions

  20. Combining Next-Generation Sequencing and Microarray Technology into a Transcriptomics Approach for the Non-Model Organism Chironomus riparius

    Science.gov (United States)

    Marinković, Marino; de Leeuw, Wim C.; de Jong, Mark; Kraak, Michiel H. S.; Admiraal, Wim; Breit, Timo M.; Jonker, Martijs J.

    2012-01-01

    Whole-transcriptome gene-expression analyses are commonly performed in species that have a sequenced genome and for which microarrays are commercially available. To do such analyses in species with no or limited genome data, i.e. non-model organisms, necessary transcriptomics resources, i.e. an annotated transcriptome and a validated gene-expression microarray, must first be developed. The aim of the present study was to establish an advanced approach for developing transcriptomics resources for non-model organisms by combining next-generation sequencing (NGS) and microarray technology. We applied our approach to the non-biting midge Chironomus riparius, an ecologically relevant species that is widely used in sediment ecotoxicity testing. We sampled extensively covering all C. riparius developmental stages as well as toxicant exposed larvae and obtained from a normalized cDNA library 1.5 M NGS reads totalling 501 Mbp. Using the NGS data we developed transcriptomics resources in several steps. First, we designed 844 k probes directly on the NGS reads, as well as 76 k probes targeting expressed sequence tags of related species. These probes were tested for their affinity to C. riparius DNA and mRNA, by performing two biological experiments with a 1 M probe-selection microarray that contained the entire probe-library. Subsequently, the 1.5 M NGS reads were assembled into 23,709 isotigs and 135,082 singletons, which were associated to ∼55 k, respectively, ∼61 k gene ontology terms and which corresponded together to 22,593 unique protein accessions. An algorithm was developed that took the assembly and the probe affinities to DNA and mRNA into account, what resulted in 59 k highly-reliable probes that targeted uniquely 95% of the isotigs and 18% of the singletons. Concluding, our approach allowed the development of high-quality transcriptomics resources for C. riparius, and is applicable to any non-model organism. It is expected, that these resources will advance

  1. Microarray profiling of mononuclear peripheral blood cells identifies novel candidate genes related to chemoradiation response in rectal cancer.

    Directory of Open Access Journals (Sweden)

    Pablo Palma

    Full Text Available Preoperative chemoradiation significantly improves oncological outcome in locally advanced rectal cancer. However there is no effective method of predicting tumor response to chemoradiation in these patients. Peripheral blood mononuclear cells have emerged recently as pathology markers of cancer and other diseases, making possible their use as therapy predictors. Furthermore, the importance of the immune response in radiosensivity of solid organs led us to hypothesized that microarray gene expression profiling of peripheral blood mononuclear cells could identify patients with response to chemoradiation in rectal cancer. Thirty five 35 patients with locally advanced rectal cancer were recruited initially to perform the study. Peripheral blood samples were obtained before neaodjuvant treatment. RNA was extracted and purified to obtain cDNA and cRNA for hybridization of microarrays included in Human WG CodeLink bioarrays. Quantitative real time PCR was used to validate microarray experiment data. Results were correlated with pathological response, according to Mandard´s criteria and final UICC Stage (patients with tumor regression grade 1-2 and downstaging being defined as responders and patients with grade 3-5 and no downstaging as non-responders. Twenty seven out of 35 patients were finally included in the study. We performed a multiple t-test using Significance Analysis of Microarrays, to find those genes differing significantly in expression, between responders (n = 11 and non-responders (n = 16 to CRT. The differently expressed genes were: BC 035656.1, CIR, PRDM2, CAPG, FALZ, HLA-DPB2, NUPL2, and ZFP36. The measurement of FALZ (p = 0.029 gene expression level determined by qRT-PCR, showed statistically significant differences between the two groups. Gene expression profiling reveals novel genes in peripheral blood samples of mononuclear cells that could predict responders and non-responders to chemoradiation in patients with

  2. DNA Microarray Detection of 18 Important Human Blood Protozoan Species.

    Science.gov (United States)

    Chen, Mu-Xin; Ai, Lin; Chen, Jun-Hu; Feng, Xin-Yu; Chen, Shao-Hong; Cai, Yu-Chun; Lu, Yan; Zhou, Xiao-Nong; Chen, Jia-Xu; Hu, Wei

    2016-12-01

    Accurate detection of blood protozoa from clinical samples is important for diagnosis, treatment and control of related diseases. In this preliminary study, a novel DNA microarray system was assessed for the detection of Plasmodium, Leishmania, Trypanosoma, Toxoplasma gondii and Babesia in humans, animals, and vectors, in comparison with microscopy and PCR data. Developing a rapid, simple, and convenient detection method for protozoan detection is an urgent need. The microarray assay simultaneously identified 18 species of common blood protozoa based on the differences in respective target genes. A total of 20 specific primer pairs and 107 microarray probes were selected according to conserved regions which were designed to identify 18 species in 5 blood protozoan genera. The positive detection rate of the microarray assay was 91.78% (402/438). Sensitivity and specificity for blood protozoan detection ranged from 82.4% (95%CI: 65.9% ~ 98.8%) to 100.0% and 95.1% (95%CI: 93.2% ~ 97.0%) to 100.0%, respectively. Positive predictive value (PPV) and negative predictive value (NPV) ranged from 20.0% (95%CI: 2.5% ~ 37.5%) to 100.0% and 96.8% (95%CI: 95.0% ~ 98.6%) to 100.0%, respectively. Youden index varied from 0.82 to 0.98. The detection limit of the DNA microarrays ranged from 200 to 500 copies/reaction, similar to PCR findings. The concordance rate between microarray data and DNA sequencing results was 100%. Overall, the newly developed microarray platform provides a convenient, highly accurate, and reliable clinical assay for the determination of blood protozoan species.

  3. PreP+07: improvements of a user friendly tool to preprocess and analyse microarray data

    Directory of Open Access Journals (Sweden)

    Claros M Gonzalo

    2009-01-01

    Full Text Available Abstract Background Nowadays, microarray gene expression analysis is a widely used technology that scientists handle but whose final interpretation usually requires the participation of a specialist. The need for this participation is due to the requirement of some background in statistics that most users lack or have a very vague notion of. Moreover, programming skills could also be essential to analyse these data. An interactive, easy to use application seems therefore necessary to help researchers to extract full information from data and analyse them in a simple, powerful and confident way. Results PreP+07 is a standalone Windows XP application that presents a friendly interface for spot filtration, inter- and intra-slide normalization, duplicate resolution, dye-swapping, error removal and statistical analyses. Additionally, it contains two unique implementation of the procedures – double scan and Supervised Lowess-, a complete set of graphical representations – MA plot, RG plot, QQ plot, PP plot, PN plot – and can deal with many data formats, such as tabulated text, GenePix GPR and ArrayPRO. PreP+07 performance has been compared with the equivalent functions in Bioconductor using a tomato chip with 13056 spots. The number of differentially expressed genes considering p-values coming from the PreP+07 and Bioconductor Limma packages were statistically identical when the data set was only normalized; however, a slight variability was appreciated when the data was both normalized and scaled. Conclusion PreP+07 implementation provides a high degree of freedom in selecting and organizing a small set of widely used data processing protocols, and can handle many data formats. Its reliability has been proven so that a laboratory researcher can afford a statistical pre-processing of his/her microarray results and obtain a list of differentially expressed genes using PreP+07 without any programming skills. All of this gives support to scientists

  4. Isolation and characterization of the murine alpha-L-iduronidase cDNA

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, L.A.; Zhang, H. Nasir, J. [Univ. of British Columbia, Vancouver (Canada)] [and others

    1994-09-01

    Mucopolysaccharidosis I (MPS I) are a group of disorders caused by deficiency of the lysosomal enzyme alpha-L-iduronidase. The characterization of the human gene and the identification of mutations underlying MPS I in humans has led to the delineation of the molecular basis of this disorder. Model systems are now needed for the evaluation and development of therapeutics for this disorder. Both canine and feline models for MPS type I have been described but only the canine gene has been isolated and characterized. We report here the cloning and expression of the murine alpha-L-iduronidase cDNA. The murine cDNA was obtained by screening a mouse liver cDNA library with a probe from the human cDNA. The full length murine cDNA is 3120 base pairs in length and thus is considerably larger than both the human and canine transcripts. The increase in size is due to a 1.2 kb 3{prime} untranslated region in the murine cDNA that contains a CA dinucleotide repeat. Within the coding region the murine cDNA shows sequences. At the protein level the murine protein shows 77% similarity with the human protein and 75% similarity with the canine protein. There are significant differences in both the start and stop sites with the murine protein 9 amino acids shorter at both the N terminal signal peptide region and the C terminus. Expression of the murine cDNA in COS-1 cells resulted in a 20 fold increase in intracellular alpha-L-iduronidase activity as well as the detection of considerable enzyme activity in the culture medium. Comparison of the reported missense mutations underlying MPS I in humans (A75T, H82P, R89Q, L218P, P533R, Q310X, T366P) has shown conservation of these amino acid residues in the murine protein. The isolation of the murine iduronidase cDNA will now allow for the development of a murine model for MPS I.

  5. Digital analysis of cDNA abundance; expression profiling by means of restriction fragment fingerprinting

    Directory of Open Access Journals (Sweden)

    Regenbogen Johannes

    2002-03-01

    Full Text Available Abstract Background Gene expression profiling among different tissues is of paramount interest in various areas of biomedical research. We have developed a novel method (DADA, Digital Analysis of cDNA Abundance, that calculates the relative abundance of genes in cDNA libraries. Results DADA is based upon multiple restriction fragment length analysis of pools of clones from cDNA libraries and the identification of gene-specific restriction fingerprints in the resulting complex fragment mixtures. A specific cDNA cloning vector had to be constructed that governed missing or incomplete cDNA inserts which would generate misleading fingerprints in standard cloning vectors. Double stranded cDNA was synthesized using an anchored oligo dT primer, uni-directionally inserted into the DADA vector and cDNA libraries were constructed in E. coli. The cDNA fingerprints were generated in a PCR-free procedure that allows for parallel plasmid preparation, labeling, restriction digest and fragment separation of pools of 96 colonies each. This multiplexing significantly enhanced the throughput in comparison to sequence-based methods (e.g. EST approach. The data of the fragment mixtures were integrated into a relational database system and queried with fingerprints experimentally produced by analyzing single colonies. Due to limited predictability of the position of DNA fragments on the polyacrylamid gels of a given size, fingerprints derived solely from cDNA sequences were not accurate enough to be used for the analysis. We applied DADA to the analysis of gene expression profiles in a model for impaired wound healing (treatment of mice with dexamethasone. Conclusions The method proved to be capable of identifying pharmacologically relevant target genes that had not been identified by other standard methods routinely used to find differentially expressed genes. Due to the above mentioned limited predictability of the fingerprints, the method was yet tested only with

  6. Possible recombinogenic effect of caprolactam in the mammalian spot test.

    Science.gov (United States)

    Fahrig, R

    1989-11-01

    Tests of caprolactam in the mouse spot test showed that treatment with this compound increased the frequency of color spots among animals treated in utero. The nature of these spots suggests that caprolactam may induce spots through the induction of mitotic recombination.

  7. 7 CFR 28.423 - Middling Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Spotted Color. 28.423 Section 28.423... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Spotted Cotton § 28.423 Middling Spotted Color. Middling Spotted Color is color which is within the range represented by a set of samples in the custody of...

  8. Generation of cDNA expression libraries enriched for in-frame sequences.

    Science.gov (United States)

    Davis, C A; Benzer, S

    1997-03-18

    Bacterial cDNA expression libraries are made to reproduce protein sequences present in the mRNA source tissue. However, there is no control over which frame of the cDNA is translated, because translation of the cDNA must be initiated on vector sequence. In a library of nondirectionally cloned cDNAs, only some 8% of the protein sequences produced are expected to be correct. Directional cloning can increase this by a factor of two, but it does not solve the frame problem. We have therefore developed and tested a library construction methodology using a novel vector, pKE-1, with which translation in the correct reading frame confers kanamycin resistance on the host. Following kanamycin selection, the cDNA libraries contained 60-80% open, in-frame clones. These, compared with unselected libraries, showed a 10-fold increase in the number of matches between the cDNA-encoded proteins made by the bacteria and database protein sequences. cDNA sequencing programs will benefit from the enrichment for correct coding sequences, and screening methods requiring protein expression will benefit from the enrichment for authentic translation products.

  9. [Construction of a yeast two-hybrid cDNA library from the human testis].

    Science.gov (United States)

    Zheng, Ying; Zhang, Lu-Ping; Jia, Xiao-Qin; Wang, Hai-Yan

    2012-04-01

    To construct a human testis cDNA library for yeast two-hybrid screening. Human normal testis mRNA was purified from total RNA, and ds cDNA was synthesized and amplified using primers SMART III and CDS III oligo (dT) as the base of recombination. The purified PCR products and linearized plasmid pGADT7-Rec were co-transformed into the competent yeast Y187 and recombined by yeast homologous recombinase in the yeast cells to form an active cyclic plasmid. All the clones growing on the SD/-Leu plates were harvested to constitute a human testis cDNA library. We constructed a human testis cDNA library with high multiplication and adequate capacity, from which 2.0 x 10(6) recombinants were obtained. The amplified PCR fragments were between 0.3 kb and 4.0 kb in length. The yeast two-hybrid cDNA library of human testis was successfully constructed by the Clontech SMART method, which has prepared a ground for further studies on the molecular mechanism of spermatogenesis.

  10. [Construction of cDNA expression library of salivary gland from Boophilus microplus].

    Science.gov (United States)

    Tian, Zhan-Cheng; Liu, Guang-Yuan; Xie, Jun-Ren; Gong, Zhen-Li

    2008-10-30

    Total RNA were isolated from salivary gland dissected from partially engorged Boophilus microplus. The mRNA was purified. A library of oligo (dT)-primed cDNA with added directional EcoR I/Hind III linkers was constructed from the purified mRNA. The constructed cDNA was ligated to the EcoR I/Hind III arms of the lambda SCREEN vector. The recombinant phage DNA was packaged by phage-marker packaging extracts, resulting in a primary cDNA library with a size of 1.38x10(6) PFU. Data showed 100% of the library were recombinant and the titer of the amplified library was 2x10(9) PFU/ml. A partial cDNA encoding cytochrome oxidase C subunit II of B. microplus was screened from the expression library with rabbit serum against B. microplus salivary gland proteins. The results is suggested that the cDNA expression library has been constructed.

  11. Construction of equalized short hairpin RNA library from human brain cDNA.

    Science.gov (United States)

    Xu, Lei; Li, Jingqi; Liu, Li; Lu, Lixia; Gao, Jingxia; Li, Xueli

    2007-02-20

    Short hairpin RNA (shRNA) library is a powerful new tool for high-throughput loss-of-function genetic screens in mammalian cells. An shRNA library can be constructed from synthetic oligonucleotides or enzymatically cleaved natural cDNA. Here, we describe a new method for constructing equalized shRNA libraries from cDNA. First, enzymatically digested cDNA fragments are equalized by a suppression PCR-based method modified from suppression subtractive hybridization. The efficiency of equalization was confirmed by quantitative real-time PCR. The fragments are then converted into an shRNA library by a series of enzymatic treatments. With this new technology, we constructed a library from human brain cDNA. Sequence analysis showed that most of the randomly selected clones had inverted repeat sequences converted from different cDNA. After transfecting HEK 293T cells and detecting gene expression, three out of eight clones were demonstrated to significantly inhibit their target genes.

  12. Molecular cloning of goat 20alpha-hydroxysteroid dehydrogenase cDNA.

    Science.gov (United States)

    Jayasekara, Walimuni Samantha Nilanthi; Yonezawa, Tomohiro; Ishida, Maho; Yamanouchi, Keitaro; Nishihara, Masugi

    2004-06-01

    20Alpha-hydroxysteroid dehydrogenase (20alpha-HSD), which catalyzes the conversion of progesterone to its inactive form 20alpha-dihydroprogesterone, is expressed in murine placenta and has been suggested to play roles in maintaining pregnancy. To understand the role of 20alpha-HSD during pregnancy in the goat, as a first step, cloning and sequencing of 20alpha-HSD cDNA were performed. The full nucleotide sequence of 20alpha-HSD cDNA was determined on samples obtained from the corpus luteum at the luteal phase of the estrous cycle and the placenta in late pregnancy by RT-PCR and 3' and 5' RACE systems. Cloned 20alpha-HSD cDNA consisted of 1124 bp and belonged to the aldo-keto reductase superfamily. From the start codon to stop codon there were 323 amino acids, the same as in other species. To verify whether the protein derived from goat 20alpha-HSD cDNA had 20alpha-HSD activity, the cDNA was expressed by bacteria. Bacterially expressed goat 20alpha-HSD protein showed 20alpha-HSD enzyme activity. A tissue distribution study demonstrated that 20alpha-HSD was expressed in the placenta, but not in the adrenal gland, liver and spleen during pregnancy. The present study suggests that goat 20alpha-HSD is another member of the aldo-keto reductase superfamily and that it plays a role in the placenta during pregnancy.

  13. Sequence of a cDNA encoding turtle high mobility group 1 protein.

    Science.gov (United States)

    Zheng, Jifang; Hu, Bi; Wu, Duansheng

    2005-07-01

    In order to understand sequence information about turtle HMG1 gene, a cDNA encoding HMG1 protein of the Chinese soft-shell turtle (Pelodiscus sinensis) was amplified by RT-PCR from kidney total RNA, and was cloned, sequenced and analyzed. The results revealed that the open reading frame (ORF) of turtle HMG1 cDNA is 606 bp long. The ORF codifies 202 amino acid residues, from which two DNA-binding domains and one polyacidic region are derived. The DNA-binding domains share higher amino acid identity with homologues sequences of chicken (96.5%) and mammalian (74%) than homologues sequence of rainbow trout (67%). The polyacidic region shows 84.6% amino acid homology with the equivalent region of chicken HMG1 cDNA. Turtle HMG1 protein contains 3 Cys residues located at completely conserved positions. Conservation in sequence and structure suggests that the functions of turtle HMG1 cDNA may be highly conserved during evolution. To our knowledge, this is the first report of HMG1 cDNA sequence in any reptilian.

  14. Microarray-based analysis of fish egg quality after natural or controlled ovulation

    Directory of Open Access Journals (Sweden)

    Fostier Alexis

    2007-02-01

    Full Text Available Abstract Background The preservation of fish egg quality after ovulation-control protocols is a major issue for the development of specific biotechnological processes (e.g. nuclear transfer. Depending on the species, it is often necessary to control the timing of ovulation or induce the ovulatory process. The hormonal or photoperiodic control of ovulation can induce specific egg quality defects that have been thoroughly studied. In contrast, the impact on the egg transcriptome as a result of these manipulations has received far less attention. Furthermore, the relationship between the mRNA abundance of maternally-inherited mRNAs and the developmental potential of the egg has never benefited from genome-wide studies. Thus, the present study aimed at studying the rainbow trout (Oncorhynchus mykiss egg transcriptome after natural or controlled ovulation using 9152-cDNA microarrays. Results The analysis of egg transcriptome after natural or controlled ovulation led to the identification of 26 genes. The expression patterns of 17 of those genes were monitored by real-time PCR. We observed that the control of ovulation by both hormonal induction and photoperiod manipulation induced significant changes in the egg mRNA abundance of specific genes. A dramatic increase of Apolipoprotein C1 (APOC1 and tyrosine protein kinase HCK was observed in the eggs when a hormonal induction of ovulation was performed. In addition, both microarray and real-time PCR analyses showed that prohibitin 2 (PHB2 egg mRNA abundance was negatively correlated with developmental success. Conclusion First, we showed, for the first time in fish, that the control of ovulation using either a hormonal induction or a manipulated photoperiod can induce differences in the egg mRNA abundance of specific genes. While the impact of these modifications on subsequent embryonic development is unknown, our observations clearly show that the egg transcriptome is affected by an artificial

  15. Development of an ordered microarray of electrochemiluminescent nanosensors

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    Chovin, Arnaud; Garrigue, Patrick; Pecastaings, Gilles; Saadaoui, Hassan; Sojic, Neso

    2006-05-01

    A microarray of electrochemiluminescent (ECL) nanosensors for remote detection is reported. Such nanosensor arrays were created on the distal face of coherent optical fibre bundles by adapting near-field optical probe and nanoelectrode methodologies. The fabrication process allows the production of high-density microarrays of nanosensors where each optical aperture is surrounded by a gold nanoring electrode. The initial architecture of the optical fibre bundle is retained and thus the microarray keeps its imaging properties. The electrochemical response of the array displays a steady-state current. This feature indicates that the nanoelectrodes forming the array can be considered as diffusively independent. In other words, each ring-shaped electrode of the array probes electrochemically a different micro-environment. We also show that this microdevice can be used as an ECL nanosensor microarray. Indeed, ECL light is initiated by the gold nanoring electrode in the presence of a co-reactant biospecies, NADH. A fraction of the isotropically electrochemically generated light is collected by the same aperture, transmitted by the corresponding fibre core and eventually imaged by a CCD camera. The gold coating therefore acts as an electrode material and also to confine the ECL light in each etched core. Such nanostructured microdevice integrates ECL-light generation, collection and imaging in a microarray format.

  16. Automated multidimensional phenotypic profiling using large public microarray repositories

    Science.gov (United States)

    Xu, Min; Li, Wenyuan; James, Gareth M.; Mehan, Michael R.; Zhou, Xianghong Jasmine

    2009-01-01

    Phenotypes are complex, and difficult to quantify in a high-throughput fashion. The lack of comprehensive phenotype data can prevent or distort genotype–phenotype mapping. Here, we describe “PhenoProfiler,” a computational method that enables in silico phenotype profiling. Drawing on the principle that similar gene expression patterns are likely to be associated with similar phenotype patterns, PhenoProfiler supplements the missing quantitative phenotype information for a given microarray dataset based on other well-characterized microarray datasets. We applied our method to 587 human microarray datasets covering >14,000 samples, and confirmed that the predicted phenotype profiles are highly consistent with true phenotype descriptions. PhenoProfiler offers several unique capabilities: (i) automated, multidimensional phenotype profiling, facilitating the analysis and treatment design of complex diseases; (ii) the extrapolation of phenotype profiles beyond provided classes; and (iii) the detection of confounding phenotype factors that could otherwise bias biological inferences. Finally, because no direct comparisons are made between gene expression values from different datasets, the method can use the entire body of cross-platform microarray data. This work has produced a compendium of phenotype profiles for the National Center for Biotechnology Information GEO datasets, which can facilitate an unbiased understanding of the transcriptome-phenome mapping. The continued accumulation of microarray data will further increase the power of PhenoProfiler, by increasing the variety and the quality of phenotypes to be profiled. PMID:19590007

  17. Statistical implications of pooling RNA samples for microarray experiments

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    Landfield Philip W

    2003-06-01

    Full Text Available Abstract Background Microarray technology has become a very important tool for studying gene expression profiles under various conditions. Biologists often pool RNA samples extracted from different subjects onto a single microarray chip to help defray the cost of microarray experiments as well as to correct for the technical difficulty in getting sufficient RNA from a single subject. However, the statistical, technical and financial implications of pooling have not been explicitly investigated. Results Modeling the resulting gene expression from sample pooling as a mixture of individual responses, we derived expressions for the experimental error and provided both upper and lower bounds for its value in terms of the variability among individuals and the number of RNA samples pooled. Using "virtual" pooling of data from real experiments and computer simulations, we investigated the statistical properties of RNA sample pooling. Our study reveals that pooling biological samples appropriately is statistically valid and efficient for microarray experiments. Furthermore, optimal pooling design(s can be found to meet statistical requirements while minimizing total cost. Conclusions Appropriate RNA pooling can provide equivalent power and improve efficiency and cost-effectiveness for microarray experiments with a modest increase in total number of subjects. Pooling schemes in terms of replicates of subjects and arrays can be compared before experiments are conducted.

  18. Evaluating melanocytic lesions with single nucleotide polymorphism (SNP) chromosomal microarray.

    Science.gov (United States)

    Hedayat, Amin A; Linos, Konstantinos; Jung, Hou-Sung; Tafe, Laura J; Yan, Shaofeng; LeBlanc, Robert E; Lefferts, Joel A

    2017-12-01

    Histopathology is the gold standard for diagnosing melanocytic lesions; however, distinguishing benign versus malignant is not always clear histologically. Single nucleotide polymorphism (SNP) microarray analysis may help in making a definitive diagnosis. Here, we share our experience with the Oncoscan FFPE Assay and demonstrate its diagnostic utility in the context of ambiguous melanocytic lesions. Eleven archival melanocytic lesions, including three benign nevi, four melanomas, three BAP1-deficient Spitzoid nevi and one nevoid melanoma were selected for validation. SNP-array was performed according to the manufacturer's protocol, using the recommended 80ng of DNA; however, as little as 15ng was used if the extraction yield was lower. Concordance was assessed with H&E and various combinations of BAP1 and p16 immunohistochemical stains (IHC) and external reference laboratory chromosomal microarray results. After validation, the SNP array was utilized to make definitive diagnoses in four challenging cases. Oncoscan SNP array findings were in concordance with H&E, IHC, and reference laboratory chromosomal microarray testing. The SNP-based microarray can accurately detect copy number changes and aid in making a more definitive diagnosis of challenging melanocytic lesions. This can be accomplished using significantly less DNA than is required by other microarray technologies. Copyright © 2017. Published by Elsevier Inc.

  19. Can Zipf's law be adapted to normalize microarrays?

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    Häsler Robert

    2005-02-01

    Full Text Available Abstract Background Normalization is the process of removing non-biological sources of variation between array experiments. Recent investigations of data in gene expression databases for varying organisms and tissues have shown that the majority of expressed genes exhibit a power-law distribution with an exponent close to -1 (i.e. obey Zipf's law. Based on the observation that our single channel and two channel microarray data sets also followed a power-law distribution, we were motivated to develop a normalization method based on this law, and examine how it compares with existing published techniques. A computationally simple and intuitively appealing technique based on this observation is presented. Results Using pairwise comparisons using MA plots (log ratio vs. log intensity, we compared this novel method to previously published normalization techniques, namely global normalization to the mean, the quantile method, and a variation on the loess normalization method designed specifically for boutique microarrays. Results indicated that, for single channel microarrays, the quantile method was superior with regard to eliminating intensity-dependent effects (banana curves, but Zipf's law normalization does minimize this effect by rotating the data distribution such that the maximal number of data points lie on the zero of the log ratio axis. For two channel boutique microarrays, the Zipf's law normalizations performed as well as, or better than existing techniques. Conclusion Zipf's law normalization is a useful tool where the Quantile method cannot be applied, as is the case with microarrays containing functionally specific gene sets (boutique arrays.

  20. Advanced Data Mining of Leukemia Cells Micro-Arrays

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    Ryan M. Pierce

    2009-12-01

    Full Text Available This paper provides continuation and extensions of previous research by Segall and Pierce (2009a that discussed data mining for micro-array databases of Leukemia cells for primarily self-organized maps (SOM. As Segall and Pierce (2009a and Segall and Pierce (2009b the results of applying data mining are shown and discussed for the data categories of microarray databases of HL60, Jurkat, NB4 and U937 Leukemia cells that are also described in this article. First, a background section is provided on the work of others pertaining to the applications of data mining to micro-array databases of Leukemia cells and micro-array databases in general. As noted in predecessor article by Segall and Pierce (2009a, micro-array databases are one of the most popular functional genomics tools in use today. This research in this paper is intended to use advanced data mining technologies for better interpretations and knowledge discovery as generated by the patterns of gene expressions of HL60, Jurkat, NB4 and U937 Leukemia cells. The advanced data mining performed entailed using other data mining tools such as cubic clustering criterion, variable importance rankings, decision trees, and more detailed examinations of data mining statistics and study of other self-organized maps (SOM clustering regions of workspace as generated by SAS Enterprise Miner version 4. Conclusions and future directions of the research are also presented.