• Title/Summary/Keyword: gene set

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Biological Feature Selection and Disease Gene Identification using New Stepwise Random Forests

  • Hwang, Wook-Yeon
    • Industrial Engineering and Management Systems
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    • v.16 no.1
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    • pp.64-79
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    • 2017
  • Identifying disease genes from human genome is a critical task in biomedical research. Important biological features to distinguish the disease genes from the non-disease genes have been mainly selected based on traditional feature selection approaches. However, the traditional feature selection approaches unnecessarily consider many unimportant biological features. As a result, although some of the existing classification techniques have been applied to disease gene identification, the prediction performance was not satisfactory. A small set of the most important biological features can enhance the accuracy of disease gene identification, as well as provide potentially useful knowledge for biologists or clinicians, who can further investigate the selected biological features as well as the potential disease genes. In this paper, we propose a new stepwise random forests (SRF) approach for biological feature selection and disease gene identification. The SRF approach consists of two stages. In the first stage, only important biological features are iteratively selected in a forward selection manner based on one-dimensional random forest regression, where the updated residual vector is considered as the current response vector. We can then determine a small set of important biological features. In the second stage, random forests classification with regard to the selected biological features is applied to identify disease genes. Our extensive experiments show that the proposed SRF approach outperforms the existing feature selection and classification techniques in terms of biological feature selection and disease gene identification.

Comparison of Invariant NKT Cells with Conventional T Cells by Using Gene Set Enrichment Analysis (GSEA)

  • Oh, Sae-Jin;Ahn, Ji-Ye;Chung, Doo-Hyun
    • IMMUNE NETWORK
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    • v.11 no.6
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    • pp.406-411
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    • 2011
  • Background: Invariant Natural killer T (iNKT) cells, a distinct subset of CD1d-restricted T cells with invariant $V{\alpha}{\beta}$ TCR, functionally bridge innate and adaptive immunity. While iNKT cells share features with conventional T cells in some functional aspects, they simultaneously produce large amount of Th1 and Th2 cytokines upon T-cell receptor (TCR) ligation. However, gene expression pattern in two types of cells has not been well characterized. Methods: we performed comparative microarray analyses of gene expression in murine iNKT cells and conventional $CD4^+CD25^-$ ${\gamma}{\delta}TCR^-$ T cells by using Gene Set Enrichment Analysis (GSEA) method. Results: Here, we describe profound differences in gene expression pattern between iNKT cells and conventional $CD4^+CD25^-$ ${\gamma}{\delta}TCR^-$ T cells. Conclusion: Our results provide new insights into the functional competence of iNKT cells and a better understanding of their various roles during immune responses.

An improvement on fuzzy seismic fragility analysis using gene expression programming

  • Ebrahimi, Elaheh;Abdollahzadeh, Gholamreza;Jahani, Ehsan
    • Structural Engineering and Mechanics
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    • v.83 no.5
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    • pp.577-591
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    • 2022
  • This paper develops a comparatively time-efficient methodology for performing seismic fragility analysis of the reinforced concrete (RC) buildings in the presence of uncertainty sources. It aims to appraise the effectiveness of any variation in the material's mechanical properties as epistemic uncertainty, and the record-to-record variation as aleatory uncertainty in structural response. In this respect, the fuzzy set theory, a well-known 𝛼-cut approach, and the Genetic Algorithm (GA) assess the median of collapse fragility curves as a fuzzy response. GA is requisite for searching the maxima and minima of the objective function (median fragility herein) in each membership degree, 𝛼. As this is a complicated and time-consuming process, the authors propose utilizing the Gene Expression Programming-based (GEP-based) equation for reducing the computational analysis time of the case study building significantly. The results indicate that the proposed structural analysis algorithm on the derived GEP model is able to compute the fuzzy median fragility about 33.3% faster, with errors less than 1%.

Gene Expression Signatures for Compound Response in Cancers

  • He, Ningning;Yoon, Suk-Joon
    • Genomics & Informatics
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    • v.9 no.4
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    • pp.173-180
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    • 2011
  • Recent trends in generating multiple, large-scale datasets provide new challenges to manipulating the relationship of different types of components, such as gene expression and drug response data. Integrative analysis of compound response and gene expression datasets generates an opportunity to capture the possible mechanism of compounds by using signature genes on diverse types of cancer cell lines. Here, we integrated datasets of compound response and gene expression profiles on NCI60 cell lines and constructed a network, revealing the relationship for 801 compounds and 341 gene probes. As examples, obtusol, which shows an exclusive sensitivity on a small number of colon cell lines, is related to a set of gene probes that have unique overexpression in colon cell lines. We also found that the SLC7A11 gene, a direct target of miR-26b, might be a key element in understanding the action of many diverse classes of anticancer compounds. We demonstrated that this network might be useful for studying the mechanisms of varied compound response on diverse cancer cell lines.

Development of Species-Specific Primers for PCR Identification of Lactobacillus hilgardii and Lactobacillus farciminis in Kimchi

  • Lee, Myung-Ki;Ku, Kyung-Hyung;Kim, Young-Jin;Kim, Kyung-Hee;Kim, Yu-Ri;Yang, Hye-Jung
    • Preventive Nutrition and Food Science
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    • v.15 no.2
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    • pp.159-166
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    • 2010
  • The aim of this study was to develop species-specific primer sets for kimchi Lactobacillus. Known gene sequences of Lactobacillus 16S rRNA were collected from the NCBI Gene bank, and 69 primer sets were designed using the homologous gene sequence. Six species of kimchi Lactobacilli were used as reference strains: Lactobacillus brevis KCTC3102, Lactobacillus farciminis KCTC3681, Lactobacillus fermentum KCTC3112, Lactobacillus hilgardii KCTC3500, Lactobacillus plantarum KCTC3099, and Lactobacillus sanfranciscensis KCTC3205. PCR amplification and gel electrophoresis were performed to identify the accuracy and specificity of the developed primer set. The results show that the primer set of 5'-aagcctgcgaaggcaag-3' & 5'-aggccaccggctttg-3', 5'-acatactatgcaaatctaagagattagacg-3' & 5'-actgagaatggctttaagagattagcttac-3' resulted in a specific PCR band on L. hilgardii, and primer set of 5'-ctaataccgcataacaactactttcacat-3' & 5'-aacttaataaaccgcctacattctctttac-3' on L. farciminis. The results indicate that the developed primer sets can provide a useful tool for the identification and differentiation of L. hilgardii and L. farciminis from other Lactobacillus species of kimchi.

Rapid Enumeration of Listeria monocytogenes in Pork Meat Using Competitive PCR

  • Lim, Hyung-Kun;Hong, Chong-Hae;Choi, Weon-Sang
    • Food Science and Biotechnology
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    • v.14 no.3
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    • pp.387-391
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    • 2005
  • Competitive polymerase chain reaction (cPCR) was used to develop a direct enumeration method of Listeria monocytogenes in pork meat. Pork meat was artificially inoculated with L. monocytogenes and DNA was extracted using guanidine thiocyanate-phenol-chloroform and subjected to PCR amplification. Sixteen primer sets for L. monocytogenes hlyA gene were tested for sensitive detection and the DG69/DG74 primer set was selected. The detection limit achieved with this primer set was as low as 860 colony-forming units (cfu) per 0.1 g of pork meat. When the samples were cultured at $30^{\circ}C$ for 16 hr in Brain Heart Infusion (BHI) medium, even a single bacterium could be detected with this primer set by PCR. For cPCR, the hlyA gene, which features a 148 bp-deletion, was cloned in the pGEM-4Z vector. A known amount of competitor DNA which has the same primer binding sites was co-amplified with L. monocytogenes total DNA from the artificially inoculated pork meat. The cell-number determined by cPCR was approximately equal to cfu from the Most Probable Number (MPN) method. The whole procedure took only 5 hr.

A hybrid method to compose an optimal gene set for multi-class classification using mRMR and modified particle swarm optimization (mRMR과 수정된 입자군집화 방법을 이용한 다범주 분류를 위한 최적유전자집단 구성)

  • Lee, Sunho
    • The Korean Journal of Applied Statistics
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    • v.33 no.6
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    • pp.683-696
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    • 2020
  • The aim of this research is to find an optimal gene set that provides highly accurate multi-class classification with a minimum number of genes. A two-stage procedure is proposed: Based on minimum redundancy and maximum relevance (mRMR) framework, several statistics to rank differential expression genes and K-means clustering to reduce redundancy between genes are used for data filtering procedure. And a particle swarm optimization is modified to select a small subset of informative genes. Two well known multi-class microarray data sets, ALL and SRBCT, are analyzed to indicate the effectiveness of this hybrid method.

Non-Invasive Sex Determination of Asiatic Black Bear (Ursus thibetanus) via Sex-Specific Amplification of the Amelogenin Gene

  • Baek-Jun Kim
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.4
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    • pp.154-158
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    • 2023
  • The Asiatic black bear, Ursus thibetanus, is among the most threatened or endangered species in Asia. For its conservation and management, sex identification of U. thibetanus using non-invasive samples (e.g., hair and/or feces) is potentially valuable. In this study, a non-invasive molecular method for sex identification of U. thibetanus samples collected from various countries was first utilized, and it was based on polymerase chain reaction (PCR) amplification of the amelogenin gene via PCRs. Thirty-three bear DNA samples, extracted not only from blood (n=9) but also from hair (n=18) and feces (n=6), were used. We performed sex-specific PCR amplifications of the amelogenin gene using a primer set, SE47 and SE48. The primer set could successfully amplify a single X-specific band for females and both X- and Y-specific bands for males from all blood (100%) and hair (100%) samples. In addition, the primer set could distinguish the sex of bears in four out of a total of six fecal samples (approximately 67%). This study's findings suggest that this molecular method can be applied to sex identification of Asiatic black bears from various Asian regions using non-invasive samples, such as hair and feces.

Fine-tuning of gene expression dynamics by the Set2-Rpd3S pathway

  • Lee, Bo Bae;Kim, Ji Hyun;Kim, TaeSoo
    • BMB Reports
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    • v.50 no.4
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    • pp.162-163
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    • 2017
  • RNA polymerase II-interacting the Set2 methyltransferase co-transcriptionally methylates histone H3 at lysine 36 within the body of genes. This modification facilitates histone deacetylation by Rpd3S HDAC in 3' transcribed regions to suppress cryptic initiation and slow elongation. Although this pathway is important for global deacetylation, no strong effects have been seen on genome-wide transcription under optimized laboratory conditions. In contrast, this pathway slows the kinetics of mRNA induction when target genes are induced upon environmental changes. Interestingly, a majority of Set2-repressed genes are overlapped by a lncRNA transcription that targets H3K36 methylation and deacetylation by Rpd3S HDAC to mRNA promoters. Furthermore, this pathway delays the induction of many cryptic transcripts upon environmental changes. Therefore, the Set2-Rpd3S HDAC pathway functions to fine-tune expression dynamics of mRNAs and ncRNAs.

Association of a miR-502-Binding Site Single Nucleotide Polymorphism in the 3'-Untranslated Region of SET8 and the TP53 Codon 72 Polymorphism with Cervical Cancer in the Chinese Population

  • Yang, Shao-Di;Cai, Yan-Lin;Jiang, Pei;Li, Wen;Tang, Jian-Xin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6505-6510
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    • 2014
  • Objective: This study was conducted to identify whether polymorphic variants of set domain-containing protein 8 (SET8) and tumor protein p53 (TP53) codon 72, either independently or jointly, might be associated with increased risk for cervical cancer. Methods: We genotyped SET8 and TP53 codon 72 polymorphisms of peripheral blood DNA from 114 cervical cancer patients and 200 controls using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and direct DNA sequencing. Results: The frequency of SET8 CC (odds ratios (OR) = 2.717, 95% CI=1.436-5.141) or TP53 GG (OR=2.168, 95% CI=1.149-4.089) genotype was associated with an increased risk of cervical cancer on comparison with the SET8 TT or TP53 CC genotypes, respectively. In additional, interaction between the SET8 and TP53 polymorphisms increased the risk of cervical cancer in a synergistic manner, with the OR being 9.913 (95% CI=2.028-48.459) for subjects carrying both SET8 CC and TP53 GG genotypes. Conclusion: These data suggest that there are significant associations between the miR-502-binding site SNP in the 3'-UTR of SET8 and the TP53 codon 72 polymorphism with cervical cancer in Chinese, and there is a gene-gene interaction.