A novel BDNF gene promoter directs expression to skeletal muscle

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Heinrich Gerhard

2003-06-01

Full Text Available Abstract Background Cell-specific expression of the gene that encodes brain-derived neurotrophic factor (BDNF is required for the normal development of peripheral sensory neurons and efficient synaptic transmission in the mature central and peripheral nervous system. The control of BDNF gene expression involves multiple tissue and cell-specific promoters that are differentially regulated. The molecular mechanisms that are responsible for tissue and cell-specific expression of these promoters are still incompletely understood. Results The cloning and analysis of three additional zebrafish (Danio rerio BDNF gene exons and two associated promoters, is reported. Among them are two exons that generate a novel tripartite mature transcript. The exons were located on the transcription unit, whose overall organization was determined by cloning, Southern blot hybridization and sequence analysis, and compared with the pufferfish (Fugu rubripes and mammalian BDNF loci, revealing a conserved but more compact organization. Structural and functional analysis of the exons, their adjacent promoters and 5' flanks, showed that they are expressed cell-specifically. The promoter associated with the 5' exon of the tripartite transcript is GC-rich, TATA-less and the 5' flank adjacent to it contains multiple Sp1, Mef2, and AP1 elements. A fusion gene containing the promoter and 1.5 KB of 5' flank is directed exclusively to skeletal muscle of transiently transfected embryos. The second promoter, whose associated 5' exon contains a 25-nucleotide segment of identity with a mammalian BDNF gene exon, was transiently expressed in yolk of the early embryo. RT-PCR analysis of total RNA from whole juvenile fish and adult female skeletal muscle revealed tissue-specific expression of the 5' exons but the novel exon could not be detected even after two rounds of nested PCR. Conclusion The zebrafish BDNF gene is as complex as the mammalian gene yet much more compact. Its exons are

An enhanced topologically significant directed random walk in cancer classification using gene expression datasets

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Choon Sen Seah

2017-12-01

Full Text Available Microarray technology has become one of the elementary tools for researchers to study the genome of organisms. As the complexity and heterogeneity of cancer is being increasingly appreciated through genomic analysis, cancerous classification is an emerging important trend. Significant directed random walk is proposed as one of the cancerous classification approach which have higher sensitivity of risk gene prediction and higher accuracy of cancer classification. In this paper, the methodology and material used for the experiment are presented. Tuning parameter selection method and weight as parameter are applied in proposed approach. Gene expression dataset is used as the input datasets while pathway dataset is used to build a directed graph, as reference datasets, to complete the bias process in random walk approach. In addition, we demonstrate that our approach can improve sensitive predictions with higher accuracy and biological meaningful classification result. Comparison result takes place between significant directed random walk and directed random walk to show the improvement in term of sensitivity of prediction and accuracy of cancer classification.

Direct and long-term detection of gene doping in conventional blood samples.

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Beiter, T; Zimmermann, M; Fragasso, A; Hudemann, J; Niess, A M; Bitzer, M; Lauer, U M; Simon, P

2011-03-01

The misuse of somatic gene therapy for the purpose of enhancing athletic performance is perceived as a coming threat to the world of sports and categorized as 'gene doping'. This article describes a direct detection approach for gene doping that gives a clear yes-or-no answer based on the presence or absence of transgenic DNA in peripheral blood samples. By exploiting a priming strategy to specifically amplify intronless DNA sequences, we developed PCR protocols allowing the detection of very small amounts of transgenic DNA in genomic DNA samples to screen for six prime candidate genes. Our detection strategy was verified in a mouse model, giving positive signals from minute amounts (20 μl) of blood samples for up to 56 days following intramuscular adeno-associated virus-mediated gene transfer, one of the most likely candidate vector systems to be misused for gene doping. To make our detection strategy amenable for routine testing, we implemented a robust sample preparation and processing protocol that allows cost-efficient analysis of small human blood volumes (200 μl) with high specificity and reproducibility. The practicability and reliability of our detection strategy was validated by a screening approach including 327 blood samples taken from professional and recreational athletes under field conditions.

Activation of Fetal γ-globin Gene Expression via Direct Protein Delivery of Synthetic Zinc-finger DNA-Binding Domains

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Mir A Hossain

2016-01-01

Full Text Available Reactivation of γ-globin expression has been shown to ameliorate disease phenotypes associated with mutations in the adult β-globin gene, including sickle cell disease. Specific mutations in the promoter of the γ-globin genes are known to prevent repression of the genes in the adult and thus lead to hereditary persistence of fetal hemoglobin. One such hereditary persistence of fetal hemoglobin is associated with a sequence located 567 bp upstream of the Gγ-globin gene which assembles a GATA-containing repressor complex. We generated two synthetic zinc-finger DNA-binding domains (ZF-DBDs targeting this sequence. The -567Gγ ZF-DBDs associated with high affinity and specificity with the target site in the γ-globin gene promoter. We delivered the -567Gγ ZF-DBDs directly to primary erythroid cells. Exposure of these cells to the recombinant -567Gγ ZF-DBDs led to increased expression of the γ-globin gene. Direct protein delivery of ZF-DBDs that compete with transcription regulatory proteins will have broad implications for modulating gene expression in analytical or therapeutic settings.

Identification of a gene expression profile that discriminates indirect-acting genotoxins from direct-acting genotoxins

Energy Technology Data Exchange (ETDEWEB)

Hu Ting; Gibson, David P.; Carr, Gregory J.; Torontali, Suzanne M.; Tiesman, Jay P.; Chaney, Joel G.; Aardema, Marilyn J

2004-05-18

During the safety evaluation process of new drugs and chemicals, a battery of genotoxicity tests is conducted starting with in vitro genotoxicity assays. Obtaining positive results in in vitro genotoxicity tests is not uncommon. Follow-up studies to determine the biological relevance of positive genotoxicity results are costly, time consuming, and utilize animals. More efficient methods, especially for identifying a putative mode of action like an indirect mechanism of genotoxicity (where DNA molecules are not the initial primary targets), would greatly improve the risk assessment for genotoxins. To this end, we are participating in an International Life Sciences Institute (ILSI) project involving studies of gene expression changes caused by model genotoxins. The purpose of the work is to evaluate gene expression tools in general, and specifically for discriminating genotoxins that are direct-acting from indirect-acting. Our lab has evaluated gene expression changes as well as micronuclei (MN) in L5178Y TK{sup +/-} mouse lymphoma cells treated with six compounds. Direct-acting genotoxins (where DNA is the initial primary target) that were evaluated included the DNA crosslinking agents, mitomycin C (MMC) and cisplatin (CIS), and an alkylating agent, methyl methanesulfonate (MMS). Indirect-acting genotoxins included hydroxyurea (HU), a ribonucleotide reductase inhibitor, taxol (TXL), a microtubule inhibitor, and etoposide (ETOP), a DNA topoisomerase II inhibitor. Microarray gene expression analysis was conducted using Affymetrix mouse oligonucleotide arrays on RNA samples derived from cells which were harvested immediately after the 4 h chemical treatment, and 20 h after the 4 h chemical treatment. The evaluation of these experimental results yields evidence of differentially regulated genes at both 4 and 24 h time points that appear to have discriminating power for direct versus indirect genotoxins, and therefore may serve as a fingerprint for classifying chemicals

A Simplified Method for Gene Knockout and Direct Screening of Recombinant Clones for Application in Paenibacillus polymyxa.

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Seong-Bin Kim

Full Text Available Paenibacillus polymyxa is a bacterium widely used in agriculture, industry, and environmental remediation because it has multiple functions including nitrogen fixation and produces various biologically active compounds. Among these compounds are the antibiotics polymyxins, and the bacterium is currently being reassessed for medical application. However, a lack of genetic tools for manipulation of P. polymyxa has limited our understanding of the biosynthesis of these compounds.To facilitate an understanding of the genetic determinants of the bacterium, we have developed a system for marker exchange mutagenesis directly on competent cells of P. polymyxa under conditions where homologous recombination is enhanced by denaturation of the suicide plasmid DNA. To test this system, we targeted P. polymyxa α-and β-amylase genes for disruption. Chloramphenicol or erythromycin resistance genes were inserted into the suicide plasmid pGEM7Z-f+ (Promega. To mediate homologous recombination and replacement of the targeted genes with the antibiotic resistance genes nucleotide sequences of the α-and β-amylase genes were cloned into the plasmid flanking the antibiotic resistance genes.We have created a simple system for targeted gene deletion in P. polymyxa E681. We propose that P. polymyxa isogenic mutants could be developed using this system of marker exchange mutagenesis. α-and β-amylase genes provide a useful tool for direct recombinant screening in P. polymyxa.

Rapid direct identification of Cryptococcus neoformans from pigeon droppings by nested PCR using CNLAC1 gene.

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Chae, H S; Park, G N; Kim, S H; Jo, H J; Kim, J T; Jeoung, H Y; An, D J; Kim, N H; Shin, B W; Kang, Y I; Chang, K S

2012-08-01

Isolation and identification of Cryptococcus neoformans and pathogenic yeast-like fungi from pigeon droppings has been taken for a long time and requires various nutrients for its growth. In this study, we attempted to establish a rapid direct identification method of Cr. neoformans from pigeon dropping samples by nested-PCR using internal transcribed spacer (ITS) CAP64 and CNLAC1 genes, polysaccharide capsule gene and laccase-associated gene to produce melanin pigment, respectively, which are common genes of yeasts. The ITS and CAP64 genes were amplified in all pathogenic yeasts, but CNLAC1 was amplified only in Cr. neoformans. The ITS gene was useful for yeast genotyping depending on nucleotide sequence. Homology of CAP64 genes among the yeasts were very high. The specificity of PCR using CNLAC1 was demonstrated in Cr. neoformans environmental strains but not in other yeast-like fungi. The CNLAC1 gene was detected in 5 serotypes of Cr. neoformans. The nested-PCR amplified up to 10(-11) μg of the genomic DNA and showed high sensitivity. All pigeon droppings among 31 Cr. neoformans-positive samples were positive and all pigeon droppings among 348 Cr. neoformans-negative samples were negative by the direct nested-PCR. In addition, after primary enrichment of pigeon droppings in Sabouraud dextrose broth, all Cr. neoformans-negative samples were negative by the nested-PCR, which showed high specificity. The nested-PCR showed high sensitivity without culture of pigeon droppings. Nested-PCR using CNLAC1 provides a rapid and reliable molecular diagnostic method to overcome weak points such as long culture time of many conventional methods.

Direct detection of hemophilia B F9 gene mutation using multiplex PCR and conformation sensitive gel electrophoresis

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Ki Young Yoo

2010-03-01

Full Text Available Purpose : The F9 gene is known to be the causative gene for hemophilia B, but unfortunately the detection rate for restriction fragment length polymorphism-based linkage analysis is only 55.6%. Direct DNA sequencing can detect 98% of mutations, but this alternative procedure is very costly. Here, we conducted multiplex polymerase chain reactions (PCRs and conformation sensitive gel electrophoresis (CSGE to perform a screened DNA sequencing for the F9 gene, and we compared the results with direct sequencing in terms of accuracy, cost, simplicity, and time consumption. Methods : A total of 27 unrelated hemophilia B patients were enrolled. Direct DNA sequencing was performed for 27 patients by a separate institute, and multiplex PCR-CSGE screened sequencing was done in our laboratory. Results of the direct DNA sequencing were used as a reference, to which the results of the multiplex PCR-CSGE screened sequencing were compared. For the patients whose mutation was not detected by the 2 methods, multiplex ligation-dependent probe amplification (MLPA was conducted. Results : With direct sequencing, the mutations could be identified from 26 patients (96.3%, whereas for multiplex PCR- CSGE screened sequencing, the mutations could be detected in 23 (85.2%. One patient’s mutation was identified by MLPA. A total of 21 different mutations were found among the 27 patients. Conclusion : Multiplex PCR-CSGE screened DNA sequencing detected 88.9% of mutations and reduced costs by 55.7% compared with direct DNA sequencing. However, it was more labor-intensive and time-consuming.

Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

KAUST Repository

Li, Yongxin; Li, Zhongrui; Yamanaka, Kazuya; Xu, Ying; Zhang, Weipeng; Vlamakis, Hera; Kolter, Roberto; Moore, Bradley S.; Qian, Pei-Yuan

2015-01-01

validating this direct cloning plug-and-playa approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation

Identification of hookworm DAF-16/FOXO response elements and direct gene targets.

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Xin Gao

2010-08-01

Full Text Available The infective stage of the parasitic nematode hookworm is developmentally arrested in the environment and needs to infect a specific host to complete its life cycle. The canine hookworm (Ancylostoma caninum is an excellent model for investigating human hookworm infections. The transcription factor of A. caninum, Ac-DAF-16, which has a characteristic fork head or "winged helix" DNA binding domain (DBD, has been implicated in the resumption of hookworm development in the host. However, the precise roles of Ac-DAF-16 in hookworm parasitism and its downstream targets are unknown. In the present study, we combined molecular techniques and bioinformatics to identify a group of Ac-DAF-16 binding sites and target genes.The DNA binding domain of Ac-DAF-16 was used to select genomic fragments by in vitro genomic selection. Twenty four bound genomic fragments were analyzed for the presence of the DAF-16 family binding element (DBE and possible alternative Ac-DAF-16 bind motifs. The 22 genes linked to these genomic fragments were identified using bioinformatics tools and defined as candidate direct gene targets of Ac-DAF-16. Their developmental stage-specific expression patterns were examined. Also, a new putative DAF-16 binding element was identified.Our results show that Ac-DAF-16 is involved in diverse biological processes throughout hookworm development. Further investigation of these target genes will provide insights into the molecular basis by which Ac-DAF-16 regulates its downstream gene network in hookworm infection.

Direct Repression of Evening Genes by CIRCADIAN CLOCK-ASSOCIATED1 in the Arabidopsis Circadian Clock.

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Kamioka, Mari; Takao, Saori; Suzuki, Takamasa; Taki, Kyomi; Higashiyama, Tetsuya; Kinoshita, Toshinori; Nakamichi, Norihito

2016-03-01

The circadian clock is a biological timekeeping system that provides organisms with the ability to adapt to day-night cycles. Timing of the expression of four members of the Arabidopsis thaliana PSEUDO-RESPONSE REGULATOR(PRR) family is crucial for proper clock function, and transcriptional control of PRRs remains incompletely defined. Here, we demonstrate that direct regulation of PRR5 by CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) determines the repression state of PRR5 in the morning. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) analyses indicated that CCA1 associates with three separate regions upstream of PRR5 CCA1 and its homolog LATE ELONGATED HYPOCOTYL (LHY) suppressed PRR5 promoter activity in a transient assay. The regions bound by CCA1 in the PRR5 promoter gave rhythmic patterns with troughs in the morning, when CCA1 and LHY are at high levels. Furthermore,ChIP-seq revealed that CCA1 associates with at least 449 loci with 863 adjacent genes. Importantly, this gene set contains genes that are repressed but upregulated incca1 lhy double mutants in the morning. This study shows that direct binding by CCA1 in the morning provides strong repression of PRR5, and repression by CCA1 also temporally regulates an evening-expressed gene set that includes PRR5. © 2016 American Society of Plant Biologists. All rights reserved.

Sendai viroplexes for epidermal growth factor receptor-directed delivery of interleukin-12 and salmosin genes to cancer cells.

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Kim, Jung Seok; Kim, Min Woo; Jeong, Hwa Yeon; Kang, Seong Jae; Park, Sang Il; Lee, Yeon Kyung; Kim, Hong Sung; Kim, Keun Sik; Park, Yong Serk

2016-07-01

The effective delivery of therapeutic genes to target cells has been a fundamental goal in cancer gene therapy because of its advantages with respect to both safety and transfection efficiency. In the present, study we describe a tumor-directed gene delivery system that demonstrates remarkable efficacy in gene delivery and minimizes the off-target effects of gene transfection. The system consists of a well-verified cationic O,O'-dimyristyl-N-lysyl glutamate (DMKE), Sendai virus fusion (F) protein and hemagglutinin-neuraminidase (HN) protein, referred to as cationic Sendai F/HN virosomes. To achieve tumor-specific recognition, anti-epidermal growth factor (EGF) receptor antibody was coupled to the surface of the virosomes containing interleukin-12 (IL-12) and/or salmosin genes that have potent anti-angiogenetic functions. Among the virosomal formulations, the anti-EGF receptor (EGFR) viroplexes, prepared via complexation of plasmid DNA (pDNA) with cationic DMKE lipid, exhibited more efficient gene transfection to tumor cells over-expressing EGF receptors compared to the neutrally-charged anti-EGFR virosomes encapsulating pDNA. In addition, the anti-EGFR viroplexes with IL-12 and salmosin genes exhibited the most effective therapeutic efficacy in a mouse tumor model. Especially when combined with doxorubicin, transfection of the two genes via the anti-EGFR viroplexes exhibited an enhanced inhibitory effect on tumor growth and metastasis in lungs. The results of the present study suggest that anti-EGFR viroplexes can be utilized as an effective strategy for tumor-directed gene delivery. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Gene expression and gene therapy imaging

International Nuclear Information System (INIS)

Rome, Claire; Couillaud, Franck; Moonen, Chrit T.W.

2007-01-01

The fast growing field of molecular imaging has achieved major advances in imaging gene expression, an important element of gene therapy. Gene expression imaging is based on specific probes or contrast agents that allow either direct or indirect spatio-temporal evaluation of gene expression. Direct evaluation is possible with, for example, contrast agents that bind directly to a specific target (e.g., receptor). Indirect evaluation may be achieved by using specific substrate probes for a target enzyme. The use of marker genes, also called reporter genes, is an essential element of MI approaches for gene expression in gene therapy. The marker gene may not have a therapeutic role itself, but by coupling the marker gene to a therapeutic gene, expression of the marker gene reports on the expression of the therapeutic gene. Nuclear medicine and optical approaches are highly sensitive (detection of probes in the picomolar range), whereas MRI and ultrasound imaging are less sensitive and require amplification techniques and/or accumulation of contrast agents in enlarged contrast particles. Recently developed MI techniques are particularly relevant for gene therapy. Amongst these are the possibility to track gene therapy vectors such as stem cells, and the techniques that allow spatiotemporal control of gene expression by non-invasive heating (with MRI guided focused ultrasound) and the use of temperature sensitive promoters. (orig.)

Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

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Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

2015-01-01

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494

Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

Science.gov (United States)

Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

2015-05-27

Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.

Directed evolution combined with synthetic biology strategies expedite semi-rational engineering of genes and genomes.

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Kang, Zhen; Zhang, Junli; Jin, Peng; Yang, Sen

2015-01-01

Owing to our limited understanding of the relationship between sequence and function and the interaction between intracellular pathways and regulatory systems, the rational design of enzyme-coding genes and de novo assembly of a brand-new artificial genome for a desired functionality or phenotype are difficult to achieve. As an alternative approach, directed evolution has been widely used to engineer genomes and enzyme-coding genes. In particular, significant developments toward DNA synthesis, DNA assembly (in vitro or in vivo), recombination-mediated genetic engineering, and high-throughput screening techniques in the field of synthetic biology have been matured and widely adopted, enabling rapid semi-rational genome engineering to generate variants with desired properties. In this commentary, these novel tools and their corresponding applications in the directed evolution of genomes and enzymes are discussed. Moreover, the strategies for genome engineering and rapid in vitro enzyme evolution are also proposed.

Do GnRH analogues directly affect human endometrial epithelial cell gene expression?

KAUST Repository

Zhang, Xiaomei

2010-03-04

We examined whether Gonadotrophin-releasing hormone (GnRH) analogues [leuprolide acetate (LA) and ganirelix acetate (GA)] modulate gene expression in Ishikawa cells used as surrogate for human endometrial epithelial cells in vitro. The specific aims were: (i) to study the modulatory effect of GnRH analogues by RT-PCR [in the absence and presence of E2 and P4, and cyclic adenosine monophos-phate (cAMP)] on mRNA expression of genes modulated during the window of implantation in GnRH analogues/rFSH-treated assisted reproductive technology cycles including OPTINEURIN (OPTN), CHROMATIN MODIFYING PROTEIN (CHMP1A), PROSAPOSIN (PSAP), IGFBP-5 and SORTING NEXIN 7 (SNX7), and (ii) to analyze the 5\\'-flanking regions of such genes for the presence of putative steroid-response elements [estrogen-response elements (EREs) and P4-response element (PREs)]. Ishikawa cells were cytokeratin+/vimentin2 and expressed ERa,ERb, PR and GnRH-R proteins. At 6 and 24 h, neither LA nor GA alone had an effect on gene expression. GnRH analogues alone or following E2 and/or P4 co-incubation for 24 h also had no effect on gene expression, but P4 significantly increased expression of CHMP1A.E2 + P4 treatment for 4 days, alone or followed by GA, had no effect, but E2 + P4 treatment followed by LA significantly decreased IGFBP-5 expression. The addition of 8-Br cAMP did not modify gene expression, with the exception of IGFBP-5 that was significantly increased. The GnRH analogues did not modify intracellular cAMP levels. We identified conserved EREs for OPN, CHMP1A, SNX7 and PSAP and PREs for SNX7. We conclude that GnRH analogues appear not to have major direct effects on gene expression of human endo-metrial epithelial cells in vitro. © The Author 2010. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

Evolutionary dynamics of DNA-binding sites and direct target genes of a floral master regulatory transcription factor [RNA-Seq

NARCIS (Netherlands)

Muiño, J.M.; Bruijn, de S.A.; Vingron, Martin; Angenent, G.C.; Kaufmann, Kerstin

2015-01-01

Plant development is controlled by transcription factors (TFs) which form complex gene-regulatory networks. Genome-wide TF DNA-binding studies revealed that these TFs have several thousands of binding sites in the Arabidopsis genome, and may regulate the expression of many genes directly. Given the

Hypoxia-inducible factor directs POMC gene to mediate hypothalamic glucose sensing and energy balance regulation.

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Hai Zhang

2011-07-01

Full Text Available Hypoxia-inducible factor (HIF is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance.

Hypoxia-Inducible Factor Directs POMC Gene to Mediate Hypothalamic Glucose Sensing and Energy Balance Regulation

Science.gov (United States)

Zhang, Hai; Zhang, Guo; Gonzalez, Frank J.; Park, Sung-min; Cai, Dongsheng

2011-01-01

Hypoxia-inducible factor (HIF) is a nuclear transcription factor that responds to environmental and pathological hypoxia to induce metabolic adaptation, vascular growth, and cell survival. Here we found that HIF subunits and HIF2α in particular were normally expressed in the mediobasal hypothalamus of mice. Hypothalamic HIF was up-regulated by glucose to mediate the feeding control of hypothalamic glucose sensing. Two underlying molecular pathways were identified, including suppression of PHDs by glucose metabolites to prevent HIF2α degradation and the recruitment of AMPK and mTOR/S6K to regulate HIF2α protein synthesis. HIF activation was found to directly control the transcription of POMC gene. Genetic approach was then employed to develop conditional knockout mice with HIF inhibition in POMC neurons, revealing that HIF loss-of-function in POMC neurons impaired hypothalamic glucose sensing and caused energy imbalance to promote obesity development. The metabolic effects of HIF in hypothalamic POMC neurons were independent of leptin signaling or pituitary ACTH pathway. Hypothalamic gene delivery of HIF counteracted overeating and obesity under conditions of nutritional excess. In conclusion, HIF controls hypothalamic POMC gene to direct the central nutrient sensing in regulation of energy and body weight balance. PMID:21814490

PMS2 gene mutational analysis: direct cDNA sequencing to circumvent pseudogene interference.

Science.gov (United States)

Wimmer, Katharina; Wernstedt, Annekatrin

2014-01-01

The presence of highly homologous pseudocopies can compromise the mutation analysis of a gene of interest. In particular, when using PCR-based strategies, pseudogene co-amplification has to be effectively prevented. This is often achieved by using primers designed to be parental gene specific according to the reference sequence and by applying stringent PCR conditions. However, there are cases in which this approach is of limited utility. For example, it has been shown that the PMS2 gene exchanges sequences with one of its pseudogenes, named PMS2CL. This results in functional PMS2 alleles containing pseudogene-derived sequences at their 3'-end and in nonfunctional PMS2CL pseudogene alleles that contain gene-derived sequences. Hence, the paralogues cannot be distinguished according to the reference sequence. This shortcoming can be effectively circumvented by using direct cDNA sequencing. This approach is based on the selective amplification of PMS2 transcripts in two overlapping 1.6-kb RT-PCR products. In addition to avoiding pseudogene co-amplification and allele dropout, this method has also the advantage that it allows to effectively identify deletions, splice mutations, and de novo retrotransposon insertions that escape the detection of most DNA-based mutation analysis protocols.

Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

KAUST Repository

Li, Yongxin

2015-03-24

Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning plug-and-playa approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

Directed natural product biosynthesis gene cluster capture and expression in the model bacterium Bacillus subtilis

Science.gov (United States)

Li, Yongxin; Li, Zhongrui; Yamanaka, Kazuya; Xu, Ying; Zhang, Weipeng; Vlamakis, Hera; Kolter, Roberto; Moore, Bradley S.; Qian, Pei-Yuan

2015-03-01

Bacilli are ubiquitous low G+C environmental Gram-positive bacteria that produce a wide assortment of specialized small molecules. Although their natural product biosynthetic potential is high, robust molecular tools to support the heterologous expression of large biosynthetic gene clusters in Bacillus hosts are rare. Herein we adapt transformation-associated recombination (TAR) in yeast to design a single genomic capture and expression vector for antibiotic production in Bacillus subtilis. After validating this direct cloning ``plug-and-play'' approach with surfactin, we genetically interrogated amicoumacin biosynthetic gene cluster from the marine isolate Bacillus subtilis 1779. Its heterologous expression allowed us to explore an unusual maturation process involving the N-acyl-asparagine pro-drug intermediates preamicoumacins, which are hydrolyzed by the asparagine-specific peptidase into the active component amicoumacin A. This work represents the first direct cloning based heterologous expression of natural products in the model organism B. subtilis and paves the way to the development of future genome mining efforts in this genus.

Gene array analysis of neural crest cells identifies transcription factors necessary for direct conversion of embryonic fibroblasts into neural crest cells

Directory of Open Access Journals (Sweden)

Tsutomu Motohashi

2016-03-01

Full Text Available Neural crest cells (NC cells are multipotent cells that emerge from the edge of the neural folds and migrate throughout the developing embryo. Although the gene regulatory network for generation of NC cells has been elucidated in detail, it has not been revealed which of the factors in the network are pivotal to directing NC identity. In this study we analyzed the gene expression profile of a pure NC subpopulation isolated from Sox10-IRES-Venus mice and investigated whether these genes played a key role in the direct conversion of Sox10-IRES-Venus mouse embryonic fibroblasts (MEFs into NC cells. The comparative molecular profiles of NC cells and neural tube cells in 9.5-day embryos revealed genes including transcription factors selectively expressed in developing trunk NC cells. Among 25 NC cell-specific transcription factor genes tested, SOX10 and SOX9 were capable of converting MEFs into SOX10-positive (SOX10+ cells. The SOX10+ cells were then shown to differentiate into neurons, glial cells, smooth muscle cells, adipocytes and osteoblasts. These SOX10+ cells also showed limited self-renewal ability, suggesting that SOX10 and SOX9 directly converted MEFs into NC cells. Conversely, the remaining transcription factors, including well-known NC cell specifiers, were unable to convert MEFs into SOX10+ NC cells. These results suggest that SOX10 and SOX9 are the key factors necessary for the direct conversion of MEFs into NC cells.

Evolutionary dynamics of DNA-binding sites and direct target genes of a floral master regulatory transcription factor [ChIP-Seq

NARCIS (Netherlands)

Muiño, J.M.; Bruijn, de S.A.; Vingron, Martin; Angenent, G.C.; Kaufmann, K.

2015-01-01

Plant development is controlled by transcription factors (TFs) which form complex gene-regulatory networks. Genome-wide TF DNA-binding studies revealed that these TFs have several thousands of binding sites in the Arabidopsis genome, and may regulate the expression of many genes directly. Given the

Generation of Directly Converted Human Osteoblasts That Are Free of Exogenous Gene and Xenogenic Protein.

Science.gov (United States)

Yamamoto, Kenta; Sato, Yoshiki; Honjo, Kenichi; Ichioka, Hiroaki; Oseko, Fumishige; Sowa, Yoshihiro; Yamamoto, Toshiro; Kanamura, Narisato; Kishida, Tsunao; Mazda, Osam

2016-11-01

Generation of osteoblasts from human somatic cells may be applicable in an effective transplantation therapy against bone diseases. Recently we established a procedure to directly convert human fibroblasts into osteoblasts by transducing some transcription factor genes via retroviral vectors. However, retroviral vector-mediated transduction may potentially cause tumor formation from the infected cells, thus a non-viral gene transfection method may be more preferable for preparation of osteoblasts to be used for transplantation therapy. Here, we constructed a plasmid vector encoding Oct4, Osterix, and L-Myc that were an appropriate combination of transcription factors for this purpose. Osteoblast-like phenotypes including high alkaline phosphatase (ALP) activity, bone matrix production and osteoblast-specific gene expression were induced in normal human fibroblasts that were transfected with the plasmid followed by culturing in osteogenic medium. The plasmid-driven directly converted osteoblasts (p-dOBs) were obtained even in the absence of a xenogenic protein. The plasmid vector sequence had fallen out of the p-dOBs. The cells formed deposition of calcified bodies in situ after transplantation into mice. These results strongly suggest that p-dOBs can be put into practical use for a novel cell-based therapy against bone diseases. J. Cell. Biochem. 117: 2538-2545, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Direct gene transfer in the Gottingen minipig CNS using stereotaxic lentiviral microinjections

DEFF Research Database (Denmark)

GLUD, AN; Hedegaard, Claus; Nielsen, Mette Slot

2010-01-01

We aim to induce direct viral mediated gene transfer in the substantia nigra (SN) of the Gottingen minipig using MRI guided stereotaxic injections of lentiviral vectors encoding enhanced green fluorescent protein (EGFP). Nine female Gottingen minipigs were injected unilaterally into the SN with 6...... per 2.5 microliters lentivirus capable of transducing cells and mediating expression of recombinant EGFP. The animals were euthanized after four (n=3) or twenty weeks (n=6). Fresh brain tissue from three animals was used for PCR. The remaining six brains were cryo- or paraffin...

Characterization of Zur-dependent genes and direct Zur targets in Yersinia pestis

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Wang Xiaoyi

2009-06-01

Full Text Available Abstract Background The zinc uptake regulator Zur is a Zn2+-sensing metalloregulatory protein involved in the maintenance of bacterial zinc homeostasis. Up to now, regulation of zinc homeostasis by Zur is poorly understood in Y. pestis. Results We constructed a zur null mutant of Y. pestis biovar microtus strain 201. Microarray expression analysis disclosed a set of 154 Zur-dependent genes of Y. pestis upon exposure to zinc rich condition. Real-time reverse transcription (RT-PCR was subsequently used to validate the microarray data. Based on the 154 Zur-dependent genes, predicted regulatory Zur motifs were used to screen for potential direct Zur targets including three putative operons znuA, znuCB and ykgM-RpmJ2. The LacZ reporter fusion analysis verified that Zur greatly repressed the promoter activity of the above three operons. The subsequent electrophoretic mobility shift assay (EMSA demonstrated that a purified Zur protein was able to bind to the promoter regions of the above three operons. The DNase I footprinting was used to identify the Zur binding sites for the above three operons, verifying the Zur box sequence as predicted previously in γ-Proteobacteria. The primer extension assay was further used to determine the transcription start sites for the above three operons and to localize the -10 and -35 elements. Zur binding sites overlapped the -10 sequence of its target promoters, which was consistent with the previous observation that Zur binding would block the entry of the RNA polymerase to repress the transcription of its target genes. Conclusion Zur as a repressor directly controls the transcription of znuA, znuCB and ykgM-RpmJ2 in Y. pestis by employing a conserved mechanism of Zur-promoter DNA association as observed in γ-Proteobacteria. Zur contributes to zinc homeostasis in Y. pestis likely through transcriptional repression of the high-affinity zinc uptake system ZnuACB and two alternative ribosomal proteins YkgM and RpmJ2.

SLAM-seq defines direct gene-regulatory functions of the BRD4-MYC axis.

Science.gov (United States)

Muhar, Matthias; Ebert, Anja; Neumann, Tobias; Umkehrer, Christian; Jude, Julian; Wieshofer, Corinna; Rescheneder, Philipp; Lipp, Jesse J; Herzog, Veronika A; Reichholf, Brian; Cisneros, David A; Hoffmann, Thomas; Schlapansky, Moritz F; Bhat, Pooja; von Haeseler, Arndt; Köcher, Thomas; Obenauf, Anna C; Popow, Johannes; Ameres, Stefan L; Zuber, Johannes

2018-05-18

Defining direct targets of transcription factors and regulatory pathways is key to understanding their roles in physiology and disease. We combined SLAM-seq [thiol(SH)-linked alkylation for the metabolic sequencing of RNA], a method for direct quantification of newly synthesized messenger RNAs (mRNAs), with pharmacological and chemical-genetic perturbation in order to define regulatory functions of two transcriptional hubs in cancer, BRD4 and MYC, and to interrogate direct responses to BET bromodomain inhibitors (BETis). We found that BRD4 acts as general coactivator of RNA polymerase II-dependent transcription, which is broadly repressed upon high-dose BETi treatment. At doses triggering selective effects in leukemia, BETis deregulate a small set of hypersensitive targets including MYC. In contrast to BRD4, MYC primarily acts as a selective transcriptional activator controlling metabolic processes such as ribosome biogenesis and de novo purine synthesis. Our study establishes a simple and scalable strategy to identify direct transcriptional targets of any gene or pathway. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

The Arabidopsis SKU5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth

Science.gov (United States)

Sedbrook, John C.; Carroll, Kathleen L.; Hung, Kai F.; Masson, Patrick H.; Somerville, Chris R.

2002-01-01

To investigate how roots respond to directional cues, we characterized a T-DNA-tagged Arabidopsis mutant named sku5 in which the roots skewed and looped away from the normal downward direction of growth on inclined agar surfaces. sku5 roots and etiolated hypocotyls were slightly shorter than normal and exhibited a counterclockwise (left-handed) axial rotation bias. The surface-dependent skewing phenotype disappeared when the roots penetrated the agar surface, but the axial rotation defect persisted, revealing that these two directional growth processes are separable. The SKU5 gene belongs to a 19-member gene family designated SKS (SKU5 Similar) that is related structurally to the multiple-copper oxidases ascorbate oxidase and laccase. However, the SKS proteins lack several of the conserved copper binding motifs characteristic of copper oxidases, and no enzymatic function could be assigned to the SKU5 protein. Analysis of plants expressing SKU5 reporter constructs and protein gel blot analysis showed that SKU5 was expressed most strongly in expanding tissues. SKU5 was glycosylated and modified by glycosyl phosphatidylinositol and localized to both the plasma membrane and the cell wall. Our observations suggest that SKU5 affects two directional growth processes, possibly by participating in cell wall expansion.

Autoantibodies directed to centromere protein F in a patient with BRCA1 gene mutation

OpenAIRE

Moghaddas, Fiona; Joshua, Fredrick; Taylor, Roberta; Fritzler, Marvin J.; Toh, Ban Hock

2016-01-01

Background Autoantibodies directed to centromere protein F were first reported in 1993 and their association with malignancy has been well documented. Case We present the case of a 48-year-old Caucasian female with a BRCA1 gene mutation associated with bilateral breast cancer. Antinuclear autoantibody immunofluorescence performed for workup of possible inflammatory arthropathy showed a high titre cell cycle related nuclear speckled pattern, with subsequent confirmation by addressable laser be...

Establishing a novel single-copy primer-internal intron-spanning PCR (spiPCR) procedure for the direct detection of gene doping.

Science.gov (United States)

Beiter, Thomas; Zimmermann, Martina; Fragasso, Annunziata; Armeanu, Sorin; Lauer, Ulrich M; Bitzer, Michael; Su, Hua; Young, William L; Niess, Andreas M; Simon, Perikles

2008-01-01

So far, the abuse of gene transfer technology in sport, so-called gene doping, is undetectable. However, recent studies in somatic gene therapy indicate that long-term presence of transgenic DNA (tDNA) following various gene transfer protocols can be found in DNA isolated from whole blood using conventional PCR protocols. Application of these protocols for the direct detection of gene doping would require almost complete knowledge about the sequence of the genetic information that has been transferred. Here, we develop and describe the novel single-copy primer-internal intron-spanning PCR (spiPCR) procedure that overcomes this difficulty. Apart from the interesting perspectives that this spiPCR procedure offers in the fight against gene doping, this technology could also be of interest in biodistribution and biosafety studies for gene therapeutic applications.

Directed mutagenesis affects recombination in Azospirillum brasilense nif genes

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C.P. Nunes

2000-12-01

Full Text Available In order to improve the gene transfer/mutagenesis system for Azospirillum brasilense, gene-cartridge mutagenesis was used to replace the nifD gene with the Tn5 kanamycin resistance gene. The construct was transferred to A. brasilense by electrotransformation. Of the 12 colonies isolated using the suicide plasmid pSUP202 as vector, only four did not show vector integration into the chromosome. Nevertheless, all 12 colonies were deficient in acetylene reduction, indicating an Nif- phenotype. Four Nif- mutants were analyzed by Southern blot, using six different probes spanning the nif and Km r genes and the plasmid vector. Apparently, several recombination events occurred in the mutant genomes, probably caused mainly by gene disruption owing to the mutagenesis technique used: resistance gene-cartridge mutagenesis combined with electrotransformation.Com o objetivo de melhorar os sistemas de transferência gênica e mutagênese para Azospirillum brasilense, a técnica de mutagênese através do uso de um gene marcador ("gene-cartridge mutagenesis" foi utilizada para substituir a região genômica de A. brasilense correspondente ao gene nifD por um segmento de DNA do transposon Tn5 contendo o gene que confere resistência ao antibiótico canamicina. A construção foi transferida para a linhagem de A. brasilense por eletrotransformação. Doze colônias transformantes foram isoladas com o plasmídeo suicida pSUP202 servindo como vetor. Dessas, somente quatro não possuíam o vetor integrado no cromossomo da bactéria. Independentemente da integração ou não do vetor, as 12 colônias foram deficientes na redução do gás acetileno, evidenciando o fenótipo Nif -. Quatro mutantes Nif - foram analisados através da técnica de Southern blot, utilizando-se seis diferentes fragmentos contendo genes nif, de resistência à canamicina e do vetor como sondas. Os resultados sugerem a ocorrência de eventos recombinacionais variados no genoma dos mutantes. A

Directed partial correlation: inferring large-scale gene regulatory network through induced topology disruptions.

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Yinyin Yuan

Full Text Available Inferring regulatory relationships among many genes based on their temporal variation in transcript abundance has been a popular research topic. Due to the nature of microarray experiments, classical tools for time series analysis lose power since the number of variables far exceeds the number of the samples. In this paper, we describe some of the existing multivariate inference techniques that are applicable to hundreds of variables and show the potential challenges for small-sample, large-scale data. We propose a directed partial correlation (DPC method as an efficient and effective solution to regulatory network inference using these data. Specifically for genomic data, the proposed method is designed to deal with large-scale datasets. It combines the efficiency of partial correlation for setting up network topology by testing conditional independence, and the concept of Granger causality to assess topology change with induced interruptions. The idea is that when a transcription factor is induced artificially within a gene network, the disruption of the network by the induction signifies a genes role in transcriptional regulation. The benchmarking results using GeneNetWeaver, the simulator for the DREAM challenges, provide strong evidence of the outstanding performance of the proposed DPC method. When applied to real biological data, the inferred starch metabolism network in Arabidopsis reveals many biologically meaningful network modules worthy of further investigation. These results collectively suggest DPC is a versatile tool for genomics research. The R package DPC is available for download (http://code.google.com/p/dpcnet/.

Beating Bias in the Directed Evolution of Proteins: Combining High-Fidelity on-Chip Solid-Phase Gene Synthesis with Efficient Gene Assembly for Combinatorial Library Construction.

Science.gov (United States)

Li, Aitao; Acevedo-Rocha, Carlos G; Sun, Zhoutong; Cox, Tony; Xu, Jia Lucy; Reetz, Manfred T

2018-02-02

Saturation mutagenesis (SM) constitutes a widely used technique in the directed evolution of selective enzymes as catalysts in organic chemistry and in the manipulation of metabolic paths and genomes, but the quality of the libraries is far from optimal due to the inherent amino acid bias. Herein, it is shown how this fundamental problem can be solved by applying high-fidelity solid-phase chemical gene synthesis on silicon chips followed by efficient gene assembly. Limonene epoxide hydrolase was chosen as the catalyst in the model desymmetrization of cyclohexene oxide with the stereoselective formation of (R,R)- and (S,S)-cyclohexane-1,2-diol. A traditional combinatorial PCR-based SM library, produced by simultaneous randomization at several residues by using a reduced amino acid alphabet, and the respective synthetic library were constructed and compared. Statistical analysis at the DNA level with massive sequencing demonstrates that, in the synthetic approach, 97 % of the theoretically possible DNA mutants are formed, whereas the traditional SM library contained only about 50 %. Screening at the protein level also showed the superiority of the synthetic library; many highly (R,R)- and (S,S)-selective variants being discovered are not found in the traditional SM library. With the prices of synthetic genes decreasing, this approach may point the way to future directed evolution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Circadian clock gene LATE ELONGATED HYPOCOTYL directly regulates the timing of floral scent emission in Petunia.

Science.gov (United States)

Fenske, Myles P; Hewett Hazelton, Kristen D; Hempton, Andrew K; Shim, Jae Sung; Yamamoto, Breanne M; Riffell, Jeffrey A; Imaizumi, Takato

2015-08-04

Flowers present a complex display of signals to attract pollinators, including the emission of floral volatiles. Volatile emission is highly regulated, and many species restrict emissions to specific times of the day. This rhythmic emission of scent is regulated by the circadian clock; however, the mechanisms have remained unknown. In Petunia hybrida, volatile emissions are dominated by products of the floral volatile benzenoid/phenylpropanoid (FVBP) metabolic pathway. Here we demonstrate that the circadian clock gene P. hybrida LATE ELONGATED HYPOCOTYL (LHY; PhLHY) regulates the daily expression patterns of the FVBP pathway genes and floral volatile production. PhLHY expression peaks in the morning, antiphasic to the expression of P. hybrida GIGANTEA (PhGI), the master scent regulator ODORANT1 (ODO1), and many other evening-expressed FVBP genes. Overexpression phenotypes of PhLHY in Arabidopsis caused an arrhythmic clock phenotype, which resembles those of LHY overexpressors. In Petunia, constitutive expression of PhLHY depressed the expression levels of PhGI, ODO1, evening-expressed FVBP pathway genes, and FVBP emission in flowers. Additionally, in the Petunia lines in which PhLHY expression was reduced, the timing of peak expression of PhGI, ODO1, and the FVBP pathway genes advanced to the morning. Moreover, PhLHY protein binds to cis-regulatory elements called evening elements that exist in promoters of ODO1 and other FVBP genes. Thus, our results imply that PhLHY directly sets the timing of floral volatile emission by restricting the expression of ODO1 and other FVBP genes to the evening in Petunia.

Challenges to develop nitrogen-fixing cereals by direct nif-gene transfer.

Science.gov (United States)

Curatti, Leonardo; Rubio, Luis M

2014-08-01

Some regions of the developing world suffer low cereal production yields due to low fertilizer inputs, among other factors. Biological N2 fixation, catalyzed by the prokaryotic enzyme nitrogenase, is an alternative to the use of synthetic N fertilizers. The molybdenum nitrogenase is an O2-labile metalloenzyme composed of the NifDK and NifH proteins, which biosyntheses require a number of nif gene products. A challenging strategy to increase cereal crop productivity in a scenario of low N fertilization is the direct transfer of nif genes into cereals. The sensitivity of nitrogenase to O2 and the apparent complexity of nitrogenase biosynthesis are the main barriers identified so far. Expression of active NifH requires the products of nifM, nifH, and possibly nifU and nifS, whereas active NifDK requires the products of nifH, nifD, nifK, nifB, nifE, nifN, and possibly nifU, nifS, nifQ, nifV, nafY, nifW and nifZ. Plastids and mitochondria are potential subcellular locations for nitrogenase. Both could provide the ATP and electrons required for nitrogenase to function but they differ in their internal O2 levels and their ability to incorporate ammonium into amino acids. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Regulation and functions of the lms homeobox gene during development of embryonic lateral transverse muscles and direct flight muscles in Drosophila.

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Dominik Müller

Full Text Available BACKGROUND: Patterning and differentiation of developing musculatures require elaborate networks of transcriptional regulation. In Drosophila, significant progress has been made into identifying the regulators of muscle development and defining their interactive networks. One major family of transcription factors involved in these processes consists of homeodomain proteins. In flies, several members of this family serve as muscle identity genes to specify the fates of individual muscles, or groups thereof, during embryonic and/or adult muscle development. Herein, we report on the expression and function of a new Drosophila homeobox gene during both embryonic and adult muscle development. METHODOLOGY/PRINCIPAL FINDINGS: The newly described homeobox gene, termed lateral muscles scarcer (lms, which has yet uncharacterized orthologs in other invertebrates and primitive chordates but not in vertebrates, is expressed exclusively in subsets of developing muscle tissues. In embryos, lms is expressed specifically in the four lateral transverse (LT muscles and their founder cells in each hemisegment, whereas in larval wing imaginal discs, it is expressed in myoblasts that develop into direct flight muscles (DFMs, which are important for proper wing positioning. We have analyzed the regulatory inputs of various other muscle identity genes with overlapping or complementary expression patterns towards the cell type specific regulation of lms expression. Further we demonstrate that lms null mutants exhibit reduced numbers of embryonic LT muscles, and null mutant adults feature held-out-wing phenotypes. We provide a detailed description of the pattern and morphology of the direct flight muscles in the wild type and lms mutant flies by using the recently-developed ultramicroscopy and show that, in the mutants, all DFMs are present and present normal morphologies. CONCLUSIONS/SIGNIFICANCE: We have identified the homeobox gene lms as a new muscle identity gene

Stratification of clear cell renal cell carcinoma (ccRCC) genomes by gene-directed copy number alteration (CNA) analysis.

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Thiesen, H-J; Steinbeck, F; Maruschke, M; Koczan, D; Ziems, B; Hakenberg, O W

2017-01-01

Tumorigenic processes are understood to be driven by epi-/genetic and genomic alterations from single point mutations to chromosomal alterations such as insertions and deletions of nucleotides up to gains and losses of large chromosomal fragments including products of chromosomal rearrangements e.g. fusion genes and proteins. Overall comparisons of copy number alterations (CNAs) presented in 48 clear cell renal cell carcinoma (ccRCC) genomes resulted in ratios of gene losses versus gene gains between 26 ccRCC Fuhrman malignancy grades G1 (ratio 1.25) and 20 G3 (ratio 0.58). Gene losses and gains of 15762 CNA genes were mapped to 795 chromosomal cytoband loci including 280 KEGG pathways. CNAs were classified according to their contribution to Fuhrman tumour gradings G1 and G3. Gene gains and losses turned out to be highly structured processes in ccRCC genomes enabling the subclassification and stratification of ccRCC tumours in a genome-wide manner. CNAs of ccRCC seem to start with common tumour related gene losses flanked by CNAs specifying Fuhrman grade G1 losses and CNA gains favouring grade G3 tumours. The appearance of recurrent CNA signatures implies the presence of causal mechanisms most likely implicated in the pathogenesis and disease-outcome of ccRCC tumours distinguishing lower from higher malignant tumours. The diagnostic quality of initial 201 genes (108 genes supporting G1 and 93 genes G3 phenotypes) has been successfully validated on published Swiss data (GSE19949) leading to a restricted CNA gene set of 171 CNA genes of which 85 genes favour Fuhrman grade G1 and 86 genes Fuhrman grade G3. Regarding these gene sets overall survival decreased with the number of G3 related gene losses plus G3 related gene gains. CNA gene sets presented define an entry to a gene-directed and pathway-related functional understanding of ongoing copy number alterations within and between individual ccRCC tumours leading to CNA genes of prognostic and predictive value.

Recombinant AAV-mediated HSVtk gene transfer with direct intratumoral injections and Tet-On regulation for implanted human breast cancer

International Nuclear Information System (INIS)

Zi-Bo, LI; Zhao-Jun, ZENG; Qian, CHEN; Sai-Qun, LUO; Wei-Xin, HU

2006-01-01

HSVtk/ganciclovir (GCV) gene therapy has been extensively studied in tumors and relies largely on the gene expression of HSVtk. Most studies, however, have failed to demonstrate any significant benefit of a controlled gene expression strategy in cancer treatment. The Tet-On system is commonly used to regulate gene expression following Dox induction. We have evaluated the antitumor effect of HSVtk/ganciclovir gene therapy under Tet-On regulation by means of adeno-associated virus-2 (AAV-2)-mediated HSVtk gene transfer with direct intratumoral injections in mice bearing breast cancer tumors. Recombinant adeno-associated virus-2 (rAAV) was constructed and transduced into MCF-7 cell line. GCV treatment to the rAAV infected MCF-7 cells was performed by MTT assay under the doxycycline (Dox) induction or without Dox induction at a vp (viral particle) number of ≥10 4 /cell. The virus was administered intratumorally to nude mice that had also received GCV intraperitoneally. The antitumor effects were evaluated by measuring tumor regression and histological analysis. We have demonstrated that GCV treatment to the infected MCF-7 cells under the Dox induction was of more inhibited effects than those without Dox induction at ≥10 4 vp/cell. In ex vivo experiments, tumor growth of BALB/C nude mice breast cancer was retarded after rAAV-2/HSVtk/Tet-On was injected into the tumors under the Dox induction. Infiltrating cells were also observed in tumors after Dox induction followed by GCV treatment and cells were profoundly damaged. The expression of HSVtk gene in MCF-7 cells and BALB/C nude mice tumors was up-regulated by Tet-On under Dox induction with reverse transcription-PCR (RT-PCR) analysis. The antitumor effect of rAAV-mediated HSVtk/GCV gene therapy under the Dox induction with direct intratumoral injections may be a useful treatment for breast cancer and other solid tumors

Direct Regulation of tRNA and 5S rRNA Gene Transcription by Polo-like Kinase 1

NARCIS (Netherlands)

Fairley, Jennifer A.; Mitchell, Louise E.; Berg, Tracy; Kenneth, Niall S.; von Schubert, Conrad; Sillje, Herman H. W.; Medema, Rene H.; Nigg, Erich A.; White, Robert J.

2012-01-01

Polo-like kinase Plk1 controls numerous aspects of cell-cycle progression. We show that it associates with tRNA and 5S rRNA genes and regulates their transcription by RNA polymerase Ill (pol Ill) through direct binding and phosphorylation of transcription factor Brit During interphase, Plk1 promotes

Gene Directed Enzyme Prodrug Therapy Using Rabbit Cytochrome P450 4B1 in Murine Colon Adenocarcinoma

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Kim, Sung Joo; Kang, Joo Hyun; Lee, Tae Sup; Kim, Kyeong Min; Woo, Kwang Sun; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2007-07-01

The conventional cancer therapy is chemotherapy, surgical resection and/or radiotherapy. Chemotherapy using cytotoxic drug has some problems with lack of tumor selectivity resulting in toxicity to normal tissues. To enhance the tumor selectivity of cytotoxic drug, the application of suicidal gene therapy technology was designed. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a non-toxic prodrug into a cytotoxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1- tk) and cytosine deaminase (cd). Recently, a new prodrug-converting enzyme based on rabbit cytochrome P450 4B1 gene (cyp4B1) has been reported for therapy of experimental brain tumor. This enzyme activates the prodrugs such as 4-ipomeanol (4-IM) and 2- aminoanthracene (2-AA) to highly reactive furane epoxide and unsaturated dialdehyde intermediate, respectively. DNA alkylation seems to be the main mechanism of cytotoxicity of these activated drugs. In this study, we isolated cyp4B1 cDNA from rabbit lung, transduced cyp4B1 expression vector into murine colon cancer cell, and then analyzed the cytotoxic properties of cyp4b1-activated 2-AA in cyp4B1 transduced cells to verify the cyp4B1 enzyme system for gene directed enzyme prodrug therapy.

Gene Directed Enzyme Prodrug Therapy Using Rabbit Cytochrome P450 4B1 in Murine Colon Adenocarcinoma

International Nuclear Information System (INIS)

Kim, Sung Joo; Kang, Joo Hyun; Lee, Tae Sup; Kim, Kyeong Min; Woo, Kwang Sun; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo

2007-01-01

The conventional cancer therapy is chemotherapy, surgical resection and/or radiotherapy. Chemotherapy using cytotoxic drug has some problems with lack of tumor selectivity resulting in toxicity to normal tissues. To enhance the tumor selectivity of cytotoxic drug, the application of suicidal gene therapy technology was designed. Suicidal gene therapy is based on the expression in tumor cells of a gene encoding an enzyme that converts a non-toxic prodrug into a cytotoxic product. Representative suicidal genes are Herpes simplex virus type 1 thymidine kinase (HSV1- tk) and cytosine deaminase (cd). Recently, a new prodrug-converting enzyme based on rabbit cytochrome P450 4B1 gene (cyp4B1) has been reported for therapy of experimental brain tumor. This enzyme activates the prodrugs such as 4-ipomeanol (4-IM) and 2- aminoanthracene (2-AA) to highly reactive furane epoxide and unsaturated dialdehyde intermediate, respectively. DNA alkylation seems to be the main mechanism of cytotoxicity of these activated drugs. In this study, we isolated cyp4B1 cDNA from rabbit lung, transduced cyp4B1 expression vector into murine colon cancer cell, and then analyzed the cytotoxic properties of cyp4b1-activated 2-AA in cyp4B1 transduced cells to verify the cyp4B1 enzyme system for gene directed enzyme prodrug therapy

Bi-directional gene set enrichment and canonical correlation analysis identify key diet-sensitive pathways and biomarkers of metabolic syndrome

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Gaora Peadar Ó

2010-10-01

Full Text Available Abstract Background Currently, a number of bioinformatics methods are available to generate appropriate lists of genes from a microarray experiment. While these lists represent an accurate primary analysis of the data, fewer options exist to contextualise those lists. The development and validation of such methods is crucial to the wider application of microarray technology in the clinical setting. Two key challenges in clinical bioinformatics involve appropriate statistical modelling of dynamic transcriptomic changes, and extraction of clinically relevant meaning from very large datasets. Results Here, we apply an approach to gene set enrichment analysis that allows for detection of bi-directional enrichment within a gene set. Furthermore, we apply canonical correlation analysis and Fisher's exact test, using plasma marker data with known clinical relevance to aid identification of the most important gene and pathway changes in our transcriptomic dataset. After a 28-day dietary intervention with high-CLA beef, a range of plasma markers indicated a marked improvement in the metabolic health of genetically obese mice. Tissue transcriptomic profiles indicated that the effects were most dramatic in liver (1270 genes significantly changed; p Conclusion Bi-directional gene set enrichment analysis more accurately reflects dynamic regulatory behaviour in biochemical pathways, and as such highlighted biologically relevant changes that were not detected using a traditional approach. In such cases where transcriptomic response to treatment is exceptionally large, canonical correlation analysis in conjunction with Fisher's exact test highlights the subset of pathways showing strongest correlation with the clinical markers of interest. In this case, we have identified selenoamino acid metabolism and steroid biosynthesis as key pathways mediating the observed relationship between metabolic health and high-CLA beef. These results indicate that this type of

Gene Editing With CRISPR/Cas9 RNA-Directed Nuclease.

Science.gov (United States)

Doetschman, Thomas; Georgieva, Teodora

2017-03-03

Genetic engineering of model organisms and cultured cells has for decades provided important insights into the mechanisms underlying cardiovascular development and disease. In the past few years the development of several nuclease systems has broadened the range of model/cell systems that can be engineered. Of these, the CRISPR (clustered regularly interspersed short palindromic repeats)/Cas9 (CRISPR-associated protein 9) system has become the favorite for its ease of application. Here we will review this RNA-guided nuclease system for gene editing with respect to its usefulness for cardiovascular studies and with an eye toward potential therapy. Studies on its off-target activity, along with approaches to minimize this activity will be given. The advantages of gene editing versus gene targeting in embryonic stem cells, including the breadth of species and cell types to which it is applicable, will be discussed. We will also cover its use in iPSC for research and possible therapeutic purposes; and we will review its use in muscular dystrophy studies where considerable progress has been made toward dystrophin correction in mice. The CRISPR/Ca9s system is also being used for high-throughput screening of genes, gene regulatory regions, and long noncoding RNAs. In addition, the CRISPR system is being used for nongene-editing purposes such as activation and inhibition of gene expression, as well as for fluorescence tagging of chromosomal regions and individual mRNAs to track their cellular location. Finally, an approach to circumvent the inability of post-mitotic cells to support homologous recombination-based gene editing will be presented. In conclusion, applications of the CRISPR/Cas system are expanding at a breath-taking pace and are revolutionizing approaches to gain a better understanding of human diseases. © 2017 American Heart Association, Inc.

Hypoxia-response element (HRE)-directed transcriptional regulation of the rat lysyl oxidase gene in response to cobalt and cadmium.

Science.gov (United States)

Gao, Song; Zhou, Jing; Zhao, Yinzhi; Toselli, Paul; Li, Wande

2013-04-01

Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Computer analysis indicated that at least four hypoxia-response element (HRE) consensuses (5'-ACGTG-3') exist in the cloned LO promoter. Treatment of rat lung fibroblasts (RFL6) with CoCl2 (Co, 10-100 μM), a chemical hypoxia reagent, enhanced LO mRNA expression and promoter activities. Overexpression of LO was associated with upregulation of hypoxia-inducible factor (HIF)-1α at mRNA levels in cobalt (Co)-treated cells. Thus, LO is a hypoxia-responsive gene. Dominant negative-HIF-1α inhibited LO promoter activities stimulated by Co. Electrophoretic mobility shift, oligonucleotide competition, and in vitro translated HIF-1α binding assays indicated that only one HRE mapped at -387/-383 relative to ATG was functionally active among four consensuses. Site-directed mutation of this HRE significantly diminished the Co-induced and LO promoter-directed expression of the reporter gene. Cadmium (Cd), an inducer of reactive oxygen species, inhibited HIF-1α mRNA expression and HIF-1α binding to the LO gene in Co-treated cells as revealed by RT-PCR and ChIP assays, respectively. Thus, modulation of the HRE activity by Co and Cd plays a critical role in LO gene transactivation.

DnaB gene product-independence of DNA polymerase III-directed repair synthesis in Escherichia coli K-12

International Nuclear Information System (INIS)

Billen, D.; Hellermann, G.R.

1977-01-01

An investigation has been carried out into the role of dnaB gene product in X-ray-induced repair synthesis carried out by DNA polymerase III in toluene-treated Escherichia coli K-12. A polAl polBlOO dnaB mutant deficient in both DNA polymerase I and II activities was used, and it was shown that the level of X-ray-induced, ATP-dependent, non-conservative DNA synthesis was, unlike semi-conservative DNA synthesis, unaffected by a temperature shift from 30 0 to 42 0 C. The dnaB gene product was not therefore necessary for DNA polymerase III-directed repair synthesis, which occurred in the absence of replicative synthesis. (U.K.)

Novel Random Mutagenesis Method for Directed Evolution.

Science.gov (United States)

Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

2017-01-01

Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

Identification of the interleukin 4 receptor alpha gene as a direct target for p73.

Science.gov (United States)

Sasaki, Yasushi; Mita, Hiroaki; Toyota, Minoru; Ishida, Setsuko; Morimoto, Ichiro; Yamashita, Toshiharu; Tanaka, Toshihiro; Imai, Kohzoh; Nakamura, Yusuke; Tokino, Takashi

2003-12-01

p73 has a high degree of structural homology to p53 and can activate transcription of p53-responsive genes. However, analysis of p73-deficient mice revealed a marked divergence in the physiological activities of p53 family genes and distinguishes p73 from p53. Mice deficient for p73 exhibit profound defects, including hippocampal dysgenesis, chronic infection, and inflammation, as well as abnormalities in pheromone sensory pathways. p73 plays important roles in neurogenesis, sensory pathways, and homeostatic regulation. Here, we found that the interleukin 4 receptor alpha (IL-4Ralpha) gene is up-regulated by p73 but not significantly by p53 in several human cancer cell lines. IL-4Ralphatranscription is also activated in response to cisplatin, a DNA-damaging agent known to induce p73. By using small interference RNA designed to target p73, we demonstrated that silencing endogenous p73 abrogates the induction of the IL-4Ralpha gene after cisplatin treatment. Furthermore, we identified a p73-binding site in the first intron of the IL-4Ralpha gene that can directly interact with the p73 protein in vivo. This p73-binding site consists of eight copies of a 10-bp consensus p53-binding motif and is a functional response element that is relatively specific for p73 among the p53 family. p73beta promoted localized nucleosomal acetylation through recruitment of coactivator p300, indicating that p73 regulates transcription of IL-4Ralpha through the unique p73-binding site. We also found that p73beta-transfected tumor cells are sensitive to IL-4-mediated apoptosis. Our data suggest that IL-4Ralpha could mediate, in part, certain immune responses and p73-dependent cell death.

Oxytocin receptor gene polymorphisms are associated with human directed social behavior in dogs (Canis familiaris.

Directory of Open Access Journals (Sweden)

Anna Kis

Full Text Available The oxytocin system has a crucial role in human sociality; several results prove that polymorphisms of the oxytocin receptor gene are related to complex social behaviors in humans. Dogs' parallel evolution with humans and their adaptation to the human environment has made them a useful species to model human social interactions. Previous research indicates that dogs are eligible models for behavioral genetic research, as well. Based on these previous findings, our research investigated associations between human directed social behaviors and two newly described (-212AG, 19131AG and one known (rs8679684 single nucleotide polymorphisms (SNPs in the regulatory regions (5' and 3' UTR of the oxytocin receptor gene in German Shepherd (N = 104 and Border Collie (N = 103 dogs. Dogs' behavior traits have been estimated in a newly developed test series consisting of five episodes: Greeting by a stranger, Separation from the owner, Problem solving, Threatening approach, Hiding of the owner. Buccal samples were collected and DNA was isolated using standard protocols. SNPs in the 3' and 5' UTR regions were analyzed by polymerase chain reaction based techniques followed by subsequent electrophoresis analysis. The gene-behavior association analysis suggests that oxytocin receptor gene polymorphisms have an impact in both breeds on (i proximity seeking towards an unfamiliar person, as well as their owner, and on (ii how friendly dogs behave towards strangers, although the mediating molecular regulatory mechanisms are yet unknown. Based on these results, we conclude that similarly to humans, the social behavior of dogs towards humans is influenced by the oxytocin system.

Oxytocin receptor gene polymorphisms are associated with human directed social behavior in dogs (Canis familiaris).

Science.gov (United States)

Kis, Anna; Bence, Melinda; Lakatos, Gabriella; Pergel, Enikő; Turcsán, Borbála; Pluijmakers, Jolanda; Vas, Judit; Elek, Zsuzsanna; Brúder, Ildikó; Földi, Levente; Sasvári-Székely, Mária; Miklósi, Adám; Rónai, Zsolt; Kubinyi, Enikő

2014-01-01

The oxytocin system has a crucial role in human sociality; several results prove that polymorphisms of the oxytocin receptor gene are related to complex social behaviors in humans. Dogs' parallel evolution with humans and their adaptation to the human environment has made them a useful species to model human social interactions. Previous research indicates that dogs are eligible models for behavioral genetic research, as well. Based on these previous findings, our research investigated associations between human directed social behaviors and two newly described (-212AG, 19131AG) and one known (rs8679684) single nucleotide polymorphisms (SNPs) in the regulatory regions (5' and 3' UTR) of the oxytocin receptor gene in German Shepherd (N = 104) and Border Collie (N = 103) dogs. Dogs' behavior traits have been estimated in a newly developed test series consisting of five episodes: Greeting by a stranger, Separation from the owner, Problem solving, Threatening approach, Hiding of the owner. Buccal samples were collected and DNA was isolated using standard protocols. SNPs in the 3' and 5' UTR regions were analyzed by polymerase chain reaction based techniques followed by subsequent electrophoresis analysis. The gene-behavior association analysis suggests that oxytocin receptor gene polymorphisms have an impact in both breeds on (i) proximity seeking towards an unfamiliar person, as well as their owner, and on (ii) how friendly dogs behave towards strangers, although the mediating molecular regulatory mechanisms are yet unknown. Based on these results, we conclude that similarly to humans, the social behavior of dogs towards humans is influenced by the oxytocin system.

Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

International Nuclear Information System (INIS)

Al-Salman, Fadheela; Plant, Nick

2012-01-01

The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

Hypoxia-Response Element (HRE)–Directed Transcriptional Regulation of the Rat Lysyl Oxidase Gene in Response to Cobalt and Cadmium

Science.gov (United States)

Li, Wande

2013-01-01

Lysyl oxidase (LO) catalyzes crosslink of collagen, elastin, and histone H1, stabilizing the extracellular matrix and cell nucleus. This enzyme displays dual functions for tumorigenesis, i.e., as a tumor suppressor inactivating the ras oncogene and as a tumor promoter enhancing malignant cell metastasis. To elucidate LO transcriptional regulation, we have cloned the 804 base pair region upstream of the translation start site (ATG) of the rat LO gene with the maximal promoter activity. Computer analysis indicated that at least four hypoxia-response element (HRE) consensuses (5′-ACGTG-3′) exist in the cloned LO promoter. Treatment of rat lung fibroblasts (RFL6) with CoCl2 (Co, 10–100 μM), a chemical hypoxia reagent, enhanced LO mRNA expression and promoter activities. Overexpression of LO was associated with upregulation of hypoxia-inducible factor (HIF)-1α at mRNA levels in cobalt (Co)–treated cells. Thus, LO is a hypoxia-responsive gene. Dominant negative-HIF-1α inhibited LO promoter activities stimulated by Co. Electrophoretic mobility shift, oligonucleotide competition, and in vitro translated HIF-1α binding assays indicated that only one HRE mapped at −387/−383 relative to ATG was functionally active among four consensuses. Site-directed mutation of this HRE significantly diminished the Co-induced and LO promoter-directed expression of the reporter gene. Cadmium (Cd), an inducer of reactive oxygen species, inhibited HIF-1α mRNA expression and HIF-1α binding to the LO gene in Co-treated cells as revealed by RT-PCR and ChIP assays, respectively. Thus, modulation of the HRE activity by Co and Cd plays a critical role in LO gene transactivation. PMID:23161664

Macrophage-specific gene functions in Spi1-directed innate immunity

NARCIS (Netherlands)

Zakrzewska, Anna; Cui, Chao; Stockhammer, Oliver W.; Benard, Erica L.; Spaink, Herman P.; Meijer, Annemarie H.

2010-01-01

The Spi1/Pu.1 transcription factor plays a crucial role in myeloid cell development in vertebrates. Despite extensive studies of Spi1, the controlled gene group remains largely unknown. To identify genes dependent on Spi1, we used a microarray strategy using a knockdown approach in zebrafish embryos

Rapid approach for cloning bacterial single-genes directly from soils ...

African Journals Online (AJOL)

Obtaining functional genes of bacteria from environmental samples usually depends on library-based approach which is not favored as its large amount of work with small possibility of positive clones. A kind of bacterial single-gene encoding glutamine synthetase (GS) was selected as example to detect the efficiency of ...

Adaptive population divergence and directional gene flow across steep elevational gradients in a climate-sensitive mammal.

Science.gov (United States)

Waterhouse, Matthew D; P Erb, Liesl; Beever, Erik A; Russello, Michael A

2018-04-25

The ecological effects of climate change have been shown in most major taxonomic groups; however, the evolutionary consequences are less well-documented. Adaptation to new climatic conditions offers a potential long-term mechanism for species to maintain viability in rapidly changing environments, but mammalian examples remain scarce. The American pika (Ochotona princeps) has been impacted by recent climate-associated extirpations and range-wide reductions in population sizes, establishing it as a sentinel mammalian species for climate change. To investigate evidence for local adaptation and reconstruct patterns of genomic diversity and gene flow across rapidly changing environments, we used a space-for-time design and restriction site-associated DNA sequencing to genotype American pikas along two steep elevational gradients at 30,966 SNPs and employed independent outlier detection methods that scanned for genotype-environment associations. We identified 338 outlier SNPs detected by two separate analyses and/or replicated in both transects, several of which were annotated to genes involved in metabolic function and oxygen transport. Additionally, we found evidence of directional gene flow primarily downslope from high-elevation populations, along with reduced gene flow at outlier loci. If this trend continues, elevational range contractions in American pikas will likely be from local extirpation rather than upward movement of low-elevation individuals; this, in turn, could limit the potential for adaptation within this landscape. These findings are of particular relevance for future conservation and management of American pikas and other elevationally-restricted, thermally-sensitive species. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pandemic H1N1 influenza A directly induces a robust and acute inflammatory gene signature in primary human bronchial epithelial cells downstream of membrane fusion

Energy Technology Data Exchange (ETDEWEB)

Paquette, Stéphane G. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Banner, David [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Chi, Le Thi Bao [Department of Microbiology, Hue University of Medicine and Pharmacy, Thua Thien Hue (Viet Nam); Carlo Urbani Centre, Hue University of Medicine and Pharmacy, Thua Thien Hue (Viet Nam); Leon, Alberto J. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong (China); Xu, Luoling; Ran, Longsi [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Huang, Stephen S.H. [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario (Canada); Farooqui, Amber [Division of Experimental Therapeutics, Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario (Canada); International Institute of Infection and Immunity, Shantou University Medical College, Shantou, Guangdong (China); and others

2014-01-05

Pandemic H1N1 influenza A (H1N1pdm) elicits stronger pulmonary inflammation than previously circulating seasonal H1N1 influenza A (sH1N1), yet mechanisms of inflammatory activation in respiratory epithelial cells during H1N1pdm infection are unclear. We investigated host responses to H1N1pdm/sH1N1 infection and virus entry mechanisms in primary human bronchial epithelial cells in vitro. H1N1pdm infection rapidly initiated a robust inflammatory gene signature (3 h post-infection) not elicited by sH1N1 infection. Protein secretion inhibition had no effect on gene induction. Infection with membrane fusion deficient H1N1pdm failed to induce robust inflammatory gene expression which was rescued with restoration of fusion ability, suggesting H1N1pdm directly triggered the inflammatory signature downstream of membrane fusion. Investigation of intra-virion components revealed H1N1pdm viral RNA (vRNA) triggered a stronger inflammatory phenotype than sH1N1 vRNA. Thus, our study is first to report H1N1pdm induces greater inflammatory gene expression than sH1N1 in vitro due to direct virus–epithelial cell interaction. - Highlights: • We investigated H1N1pdm/sH1N1 infection in primary epithelial cells. • H1N1pdm directly initiated a robust inflammatory gene signature, sH1N1 did not. • H1N1pdm viral RNA triggered a stronger response than sH1N1. • H1N1pdm induces greater response due to direct virus–cell interaction. • These results have potential to impact vaccine and therapeutic development.

Pandemic H1N1 influenza A directly induces a robust and acute inflammatory gene signature in primary human bronchial epithelial cells downstream of membrane fusion

International Nuclear Information System (INIS)

Paquette, Stéphane G.; Banner, David; Chi, Le Thi Bao; Leon, Alberto J.; Xu, Luoling; Ran, Longsi; Huang, Stephen S.H.; Farooqui, Amber

2014-01-01

Pandemic H1N1 influenza A (H1N1pdm) elicits stronger pulmonary inflammation than previously circulating seasonal H1N1 influenza A (sH1N1), yet mechanisms of inflammatory activation in respiratory epithelial cells during H1N1pdm infection are unclear. We investigated host responses to H1N1pdm/sH1N1 infection and virus entry mechanisms in primary human bronchial epithelial cells in vitro. H1N1pdm infection rapidly initiated a robust inflammatory gene signature (3 h post-infection) not elicited by sH1N1 infection. Protein secretion inhibition had no effect on gene induction. Infection with membrane fusion deficient H1N1pdm failed to induce robust inflammatory gene expression which was rescued with restoration of fusion ability, suggesting H1N1pdm directly triggered the inflammatory signature downstream of membrane fusion. Investigation of intra-virion components revealed H1N1pdm viral RNA (vRNA) triggered a stronger inflammatory phenotype than sH1N1 vRNA. Thus, our study is first to report H1N1pdm induces greater inflammatory gene expression than sH1N1 in vitro due to direct virus–epithelial cell interaction. - Highlights: • We investigated H1N1pdm/sH1N1 infection in primary epithelial cells. • H1N1pdm directly initiated a robust inflammatory gene signature, sH1N1 did not. • H1N1pdm viral RNA triggered a stronger response than sH1N1. • H1N1pdm induces greater response due to direct virus–cell interaction. • These results have potential to impact vaccine and therapeutic development

Usefulness of intra-arterial embolization method using gelfoam particles in effective gene transduction of adenoviral vector for liver-directed gene therapy: an preliminary animal study in dogs

International Nuclear Information System (INIS)

Lee, Jin Hwa; Park, Byeong Ho; Kim, Chan Sung

2003-01-01

Liver-directed gene therapy is being actively pursued and developed as a method of treating various liver diseases. A number of aspects, including gene intervention, an efficient gene delivery system, and stable transgene expression are key to the success of the chosen strategy, and to overcome problems in these areas, several tactics can be used. In this study, we assess the utility of transarterial embolization using gelfoam particles soaked in an adenovirus vector as a gene-delivery method. Using the angiographic approach, three dogs each weighing 9.5-11kg were superselectively catheterized at the left hepatic artery using a 3-F microcatheter and the coaxial method. Two of the dogs were embolized at the left hepatic artery using 3x2x2-mm and 2x1x1-mm gelfoam particles soaked in 2x10 11 particles/kg of recombinant adv. CMV.LacZ(LacZ-adv). The left hepatic artery of the remaining animal, used as a control, was infused with the same dose of lacZ-adv in the same way as before but without embolization of the left hepatic artery. Three days after embolization or the infusion of LacZ-adv, the dogs were sacrificed prior to harvest of the entire liver for the evaluation of gene transduction. X-gal staining of the liver tissue obtained was positive for hepatocytes, but the pattern and degree of gene transduction differed according to gelfoam particle size. Where this was 3x2x2 mm, gene transduction along the liver hilum varied, but where 2x1x1-mm particles were used, transduction was more even. No pathologic hepatic tissue injury or inflammation was apparent, and control liver tissue was not stained by X-gal. Serum SGOT and SGPT levels were slightly higher one day after the procedure, but had normalized by day 3. Intrahepatic transarterial embolization using gelfoam particles soaked in LacZ-adv appears to be a good method for effective liver-targed gene therapy

Usefulness of intra-arterial embolization method using gelfoam particles in effective gene transduction of adenoviral vector for liver-directed gene therapy: an preliminary animal study in dogs

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Hwa; Park, Byeong Ho; Kim, Chan Sung [Dong-A University College of Medicine, Pusan (Korea, Republic of)

2003-02-01

Liver-directed gene therapy is being actively pursued and developed as a method of treating various liver diseases. A number of aspects, including gene intervention, an efficient gene delivery system, and stable transgene expression are key to the success of the chosen strategy, and to overcome problems in these areas, several tactics can be used. In this study, we assess the utility of transarterial embolization using gelfoam particles soaked in an adenovirus vector as a gene-delivery method. Using the angiographic approach, three dogs each weighing 9.5-11kg were superselectively catheterized at the left hepatic artery using a 3-F microcatheter and the coaxial method. Two of the dogs were embolized at the left hepatic artery using 3x2x2-mm and 2x1x1-mm gelfoam particles soaked in 2x10{sup 11} particles/kg of recombinant adv. CMV.LacZ(LacZ-adv). The left hepatic artery of the remaining animal, used as a control, was infused with the same dose of lacZ-adv in the same way as before but without embolization of the left hepatic artery. Three days after embolization or the infusion of LacZ-adv, the dogs were sacrificed prior to harvest of the entire liver for the evaluation of gene transduction. X-gal staining of the liver tissue obtained was positive for hepatocytes, but the pattern and degree of gene transduction differed according to gelfoam particle size. Where this was 3x2x2 mm, gene transduction along the liver hilum varied, but where 2x1x1-mm particles were used, transduction was more even. No pathologic hepatic tissue injury or inflammation was apparent, and control liver tissue was not stained by X-gal. Serum SGOT and SGPT levels were slightly higher one day after the procedure, but had normalized by day 3. Intrahepatic transarterial embolization using gelfoam particles soaked in LacZ-adv appears to be a good method for effective liver-targed gene therapy.

Research progress in machine learning methods for gene-gene interaction detection.

Science.gov (United States)

Peng, Zhe-Ye; Tang, Zi-Jun; Xie, Min-Zhu

2018-03-20

Complex diseases are results of gene-gene and gene-environment interactions. However, the detection of high-dimensional gene-gene interactions is computationally challenging. In the last two decades, machine-learning approaches have been developed to detect gene-gene interactions with some successes. In this review, we summarize the progress in research on machine learning methods, as applied to gene-gene interaction detection. It systematically examines the principles and limitations of the current machine learning methods used in genome wide association studies (GWAS) to detect gene-gene interactions, such as neural networks (NN), random forest (RF), support vector machines (SVM) and multifactor dimensionality reduction (MDR), and provides some insights on the future research directions in the field.

Rapid and efficient CRISPR/Cas9 gene inactivation in human neurons during human pluripotent stem cell differentiation and direct reprogramming.

Science.gov (United States)

Rubio, Alicia; Luoni, Mirko; Giannelli, Serena G; Radice, Isabella; Iannielli, Angelo; Cancellieri, Cinzia; Di Berardino, Claudia; Regalia, Giulia; Lazzari, Giovanna; Menegon, Andrea; Taverna, Stefano; Broccoli, Vania

2016-11-18

The CRISPR/Cas9 system is a rapid and customizable tool for gene editing in mammalian cells. In particular, this approach has widely opened new opportunities for genetic studies in neurological disease. Human neurons can be differentiated in vitro from hPSC (human Pluripotent Stem Cells), hNPCs (human Neural Precursor Cells) or even directly reprogrammed from fibroblasts. Here, we described a new platform which enables, rapid and efficient CRISPR/Cas9-mediated genome targeting simultaneously with three different paradigms for in vitro generation of neurons. This system was employed to inactivate two genes associated with neurological disorder (TSC2 and KCNQ2) and achieved up to 85% efficiency of gene targeting in the differentiated cells. In particular, we devised a protocol that, combining the expression of the CRISPR components with neurogenic factors, generated functional human neurons highly enriched for the desired genome modification in only 5 weeks. This new approach is easy, fast and that does not require the generation of stable isogenic clones, practice that is time consuming and for some genes not feasible.

Manipulation of cell cycle progression can counteract the apparent loss of correction frequency following oligonucleotide-directed gene repair

Directory of Open Access Journals (Sweden)

Kmiec Eric B

2007-02-01

Full Text Available Abstract Background Single-stranded oligonucleotides (ssODN are used routinely to direct specific base alterations within mammalian genomes that result in the restoration of a functional gene. Despite success with the technique, recent studies have revealed that following repair events, correction frequencies decrease as a function of time, possibly due to a sustained activation of damage response signals in corrected cells that lead to a selective stalling. In this study, we use thymidine to slow down the replication rate to enhance repair frequency and to maintain substantial levels of correction over time. Results First, we utilized thymidine to arrest cells in G1 and released the cells into S phase, at which point specific ssODNs direct the highest level of correction. Next, we devised a protocol in which cells are maintained in thymidine following the repair reaction, in which the replication is slowed in both corrected and non-corrected cells and the initial correction frequency is retained. We also present evidence that cells enter a senescence state upon prolonged treatment with thymidine but this passage can be avoided by removing thymidine at 48 hours. Conclusion Taken together, we believe that thymidine may be used in a therapeutic fashion to enable the maintenance of high levels of treated cells bearing repaired genes.

Clinical and molecular characterization of a cohort of patients with novel nucleotide alterations of the Dystrophin gene detected by direct sequencing

Directory of Open Access Journals (Sweden)

Corti Stefania

2011-03-01

Full Text Available Abstract Background Duchenne and Becker Muscular dystrophies (DMD/BMD are allelic disorders caused by mutations in the dystrophin gene, which encodes a sarcolemmal protein responsible for muscle integrity. Deletions and duplications account for approximately 75% of mutations in DMD and 85% in BMD. The implementation of techniques allowing complete gene sequencing has focused attention on small point mutations and other mechanisms underlying complex rearrangements. Methods We selected 47 patients (41 families; 35 DMD, 6 BMD without deletions and duplications in DMD gene (excluded by multiplex ligation-dependent probe amplification and multiplex polymerase chain reaction analysis. This cohort was investigated by systematic direct sequence analysis to study sequence variation. We focused our attention on rare mutational events which were further studied through transcript analysis. Results We identified 40 different nucleotide alterations in DMD gene and their clinical correlates; altogether, 16 mutations were novel. DMD probands carried 9 microinsertions/microdeletions, 19 nonsense mutations, and 7 splice-site mutations. BMD patients carried 2 nonsense mutations, 2 splice-site mutations, 1 missense substitution, and 1 single base insertion. The most frequent stop codon was TGA (n = 10 patients, followed by TAG (n = 7 and TAA (n = 4. We also analyzed the molecular mechanisms of five rare mutational events. They are two frame-shifting mutations in the DMD gene 3'end in BMD and three novel splicing defects: IVS42: c.6118-3C>A, which causes a leaky splice-site; c.9560A>G, which determines a cryptic splice-site activation and c.9564-426 T>G, which creates pseudoexon retention within IVS65. Conclusion The analysis of our patients' sample, carrying point mutations or complex rearrangements in DMD gene, contributes to the knowledge on phenotypic correlations in dystrophinopatic patients and can provide a better understanding of pre-mRNA maturation defects

Acute TNF-induced repression of cell identity genes is mediated by NFκB-directed redistribution of cofactors from super-enhancers

DEFF Research Database (Denmark)

Schmidt, Søren Fisker; Larsen, Bjørk Ditlev; Loft, Anne

2015-01-01

The proinflammatory cytokine tumor necrosis factor (TNF) plays a central role in low-grade adipose tissue inflammation and development of insulin resistance during obesity. In this context, nuclear factor κ-light-chain-enhancer of activated B cells (NFκB) is directly involved and required for the...... specifically repressing super-enhancer-associated cell identity genes....... binding to the associated enhancers but rather loss of cofactors and enhancer RNA (eRNA) selectively from high-occupancy sites within super-enhancers. Based on these data, we have developed models that, with high accuracy, predict which enhancers and genes are repressed by TNF in adipocytes. We show...... that these models are applicable to other cell types where TNF represses genes associated with super-enhancers in a highly cell-type-specific manner. Our results propose a novel paradigm for NFκB-mediated repression, whereby NFκB selectively redistributes cofactors from high-occupancy enhancers, thereby...

Oral Tolerance: A New Tool for the Treatment of Gastrointestinal Inflammatory Disorders and Liver-Directed Gene Therapy

Directory of Open Access Journals (Sweden)

Yaron Ilan

1999-01-01

Full Text Available Oral tolerance is a method of downregulating an immune response by feeding antigens. The use of oral tolerance toward adenoviruses and colitis-extracted proteins for long term gene therapy and alleviation of experimental colitis, and the mechanisms of tolerance induction are presented. Adenoviruses are efficient vectors in liver-directed gene therapy; however, the antiviral immune response precludes the ability to achieve long term gene expression and prohibits the ability to reinject the recombinant virus. Oral tolerance induction via feeding of viral-extracted proteins prevented the antiadenoviral humoral and cellular immune responses, thus enabling long term gene therapy using these viruses. Moreover, pre-existing immune response to the virus was overcome by tolerance induction, enabling prolonged gene expression in a presensitized host. Inflammatory bowel diseases are immune-mediated disorders where an imbalance between proinflammatory (T helper cell type 1 and anti-inflammatory (T helper cell type 2 cytokines are thought to play a role in the pathogenesis. In the experimental colitis model, the feeding of colitis-extracted proteins downregulated the anticolon immune response. Tolerance induction toward colitis-extracted proteins ameliorated colonic inflammation as shown by decreased diarrhea and reduction of colonic ulcerations, intestinal and peritoneal adhesions, wall thickness and edema. Histological parameters for colitis were markedly improved in tolerized animals. In both models, tolerized animals developed an increase in transforming growth factor-beta, interleukin-4 and interleukin-10, and a decrease in the mRNA of interferon-gamma lymphocytes and serum levels. Adoptive transfer of tolerized lymphocytes enabled the transfer of tolerance toward adenoviruses and colon-extracted proteins. Thus, oral tolerance induces suppressor lymphocytes that mediate immune response downregulation by induction of a shift from a proinflammatory T

Direct detection of the AR-E211 G > A gene polymorphism from blood and tissue samples without DNA isolation.

Science.gov (United States)

Reptova, Silvie; Trtkova, Katerina Smesny; Kolar, Zdenek

2014-04-01

The pathogenesis of prostate cancer (CaP) involves alterations in a gene structure of the androgen receptor (AR). The single nucleotide polymorphism AR-E211 G > A localized in exon 1 of the AR gene (G1733A) was detected using direct polymerase chain reaction and restriction digestion (PCR-RFLP) method on blood and tissue samples without prior DNA isolation. We used blood samples of patients with a diagnosis of benign prostatic hyperplasia (BPH) or CaP. From monitored group of CaP patients were selected specimen in formalin-fixed paraffin-embedded tissue blocks with morphology of BPH and CaP. The main objective of our study was to develop a method based the direct PCR-RFLP analysis from blood and tissue without prior DNA isolation for faster genotyping analysis of a large number of samples. We found no statistically significant differences in allelic % of the AR-E211 G > A polymorphism between BPH and CaP patients (p ≤ 0.8462). Genotyping of the AR-E211 G > A variant in blood was not identical with tumor tissue genotyping analysis. Significant agreement between blood and tissue AR-E211 G > A polymorphism only in non-tumor tissue focus was confirmed. Although we analyzed a limited number of the tissue samples, we suppose that a presence of the minor allele A may be associated with cancer transformation-induced changes of the modified AR gene.

Site-directed mutagenesis in Petunia × hybrida protoplast system using direct delivery of purified recombinant Cas9 ribonucleoproteins.

Science.gov (United States)

Subburaj, Saminathan; Chung, Sung Jin; Lee, Choongil; Ryu, Seuk-Min; Kim, Duk Hyoung; Kim, Jin-Soo; Bae, Sangsu; Lee, Geung-Joo

2016-07-01

Site-directed mutagenesis of nitrate reductase genes using direct delivery of purified Cas9 protein preassembled with guide RNA produces mutations efficiently in Petunia × hybrida protoplast system. The clustered, regularly interspaced, short palindromic repeat (CRISPR)-CRISPR associated endonuclease 9 (CRISPR/Cas9) system has been recently announced as a powerful molecular breeding tool for site-directed mutagenesis in higher plants. Here, we report a site-directed mutagenesis method targeting Petunia nitrate reductase (NR) gene locus. This method could create mutations efficiently using direct delivery of purified Cas9 protein and single guide RNA (sgRNA) into protoplast cells. After transient introduction of RNA-guided endonuclease (RGEN) ribonucleoproteins (RNPs) with different sgRNAs targeting NR genes, mutagenesis at the targeted loci was detected by T7E1 assay and confirmed by targeted deep sequencing. T7E1 assay showed that RGEN RNPs induced site-specific mutations at frequencies ranging from 2.4 to 21 % at four different sites (NR1, 2, 4 and 6) in the PhNR gene locus with average mutation efficiency of 14.9 ± 2.2 %. Targeted deep DNA sequencing revealed mutation rates of 5.3-17.8 % with average mutation rate of 11.5 ± 2 % at the same NR gene target sites in DNA fragments of analyzed protoplast transfectants. Further analysis from targeted deep sequencing showed that the average ratio of deletion to insertion produced collectively by the four NR-RGEN target sites (NR1, 2, 4, and 6) was about 63:37. Our results demonstrated that direct delivery of RGEN RNPs into protoplast cells of Petunia can be exploited as an efficient tool for site-directed mutagenesis of genes or genome editing in plant systems.

RNA-directed DNA methylation: Mechanisms and functions

KAUST Repository

Mahfouz, Magdy M.

2010-01-01

Epigenetic RNA based gene silencing mechanisms play a major role in genome stability and control of gene expression. Transcriptional gene silencing via RNA-directed DNA methylation (RdDM) guides the epigenetic regulation of the genome in response

NTL8 Regulates Trichome Formation in Arabidopsis by Directly Activating R3 MYB Genes TRY and TCL1.

Science.gov (United States)

Tian, Hainan; Wang, Xianling; Guo, Hongyan; Cheng, Yuxin; Hou, Chunjiang; Chen, Jin-Gui; Wang, Shucai

2017-08-01

The NAM, ATAF1/2, and CUC (NAC) are plant-specific transcription factors that regulate multiple aspects of plant growth and development and plant response to environmental stimuli. We report here the identification of NTM1-LIKE8 (NTL8), a membrane-associated NAC transcription factor, as a novel regulator of trichome formation in Arabidopsis ( Arabidopsis thaliana ). From an activation-tagged Arabidopsis population, we identified a dominant, gain-of-function mutant with glabrous inflorescence stem. By using plasmid rescue and RT-PCR analyses, we found that NTL8 was tagged; thus, the mutant was named ntl8-1 Dominant ( ntl8-1D ). Recapitulation experiment further confirmed that the phenotype observed in the ntl8-1D mutant was caused by elevated expression of NTL8 Quantitative RT-PCR results showed that the expression level of the single-repeat R3 MYB genes TRIPTYCHON ( TRY ) and TRICHOMELESS1 ( TCL1 ) was elevated in the ntl8-1D mutant. Genetic analyses demonstrated that NTL8 acts upstream of TRY and TCL1 in the regulation of trichome formation. When recruited to the promoter region of the reporter gene Gal4:GUS by a fused GAL4 DNA-binding domain, NTL8 activated the expression of the reporter gene. Chromatin immunoprecipitation results indicated that TRY and TCL1 are direct targets of NTL8. However, NTL8 did not interact with SQUAMOSA PROMOTER BINDING PROTEIN LIKE9, another transcription factor that regulates the expression of TRY and TCL1 , in yeast and plant cells. Taken together, our results suggest that NTL8 negatively regulates trichome formation in Arabidopsis by directly activating the expression of TRY and TCL1 . © 2017 American Society of Plant Biologists. All Rights Reserved.

Adaptive population divergence and directional gene flow across steep elevational gradients in a climate‐sensitive mammal

Science.gov (United States)

Waterhouse, Matthew D.; Erb, Liesl P.; Beever, Erik; Russello, Michael A.

2018-01-01

The American pika is a thermally sensitive, alpine lagomorph species. Recent climate-associated population extirpations and genetic signatures of reduced population sizes range-wide indicate the viability of this species is sensitive to climate change. To test for potential adaptive responses to climate stress, we sampled pikas along two elevational gradients (each ~470 to 1640 m) and employed three outlier detection methods, BAYESCAN, LFMM, and BAYPASS, to scan for genotype-environment associations in samples genotyped at 30,763 SNP loci. We resolved 173 loci with robust evidence of natural selection detected by either two independent analyses or replicated in both transects. A BLASTN search of these outlier loci revealed several genes associated with metabolic function and oxygen transport, indicating natural selection from thermal stress and hypoxia. We also found evidence of directional gene flow primarily downslope from large high-elevation populations and reduced gene flow at outlier loci, a pattern suggesting potential impediments to the upward elevational movement of adaptive alleles in response to contemporary climate change. Finally, we documented evidence of reduced genetic diversity associated the south-facing transect and an increase in corticosterone stress levels associated with inbreeding. This study suggests the American pika is already undergoing climate-associated natural selection at multiple genomic regions. Further analysis is needed to determine if the rate of climate adaptation in the American pika and other thermally sensitive species will be able to keep pace with rapidly changing climate conditions.

Site-targeted non-viral gene delivery by direct DNA injection into the pancreatic parenchyma and subsequent in vivo electroporation in mice.

Science.gov (United States)

Sato, Masahiro; Inada, Emi; Saitoh, Issei; Ohtsuka, Masato; Nakamura, Shingo; Sakurai, Takayuki; Watanabe, Satoshi

2013-11-01

The pancreas is considered an important gene therapy target because the organ is the site of several high burden diseases, including diabetes mellitus, cystic fibrosis, and pancreatic cancer. We aimed to develop an efficient in vivo gene delivery system using non-viral DNA. Direct intra-parenchymal injection of a solution containing circular plasmid pmaxGFP DNA was performed on adult anesthetized ICR female mice. The injection site was sandwiched with a pair of tweezer-type electrode disks, and electroporated using a square-pulse generator. Green fluorescent protein (GFP) expression within the injected pancreatic portion was observed one day after gene delivery. GFP expression reduced to baseline within a week of transfection. Application of voltages over 40 V resulted in tissue damage during electroporation. We demonstrate that electroporation is effective for safe and efficient transfection of pancreatic cells. This novel gene delivery method to the pancreatic parenchyma may find application in gene therapy strategies for pancreatic diseases and in investigation of specific gene function in situ. © 2013 The Authors. Biotechnology Journal published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptions are made.

An SGS3-like protein functions in RNA-directed DNA methylation and transcriptional gene silencing in Arabidopsis

KAUST Repository

Zheng, Zhimin

2010-01-06

RNA-directed DNA methylation (RdDM) is an important epigenetic mechanism for silencing transgenes and endogenous repetitive sequences such as transposons. The RD29A promoter-driven LUCIFERASE transgene and its corresponding endogenous RD29A gene are hypermethylated and silenced in the Arabidopsis DNA demethylase mutant ros1. By screening for second-site suppressors of ros1, we identified the RDM12 locus. The rdm12 mutation releases the silencing of the RD29A-LUC transgene and the endogenous RD29A gene by reducing the promoter DNA methylation. The rdm12 mutation also reduces DNA methylation at endogenous RdDM target loci, including transposons and other repetitive sequences. In addition, the rdm12 mutation affects the levels of small interfering RNAs (siRNAs) from some of the RdDM target loci. RDM12 encodes a protein with XS and coiled-coil domains, and is similar to SGS3, which is a partner protein of RDR6 and can bind to double-stranded RNAs with a 5′ overhang, and is required for several post-transcriptional gene silencing pathways. Our results show that RDM12 is a component of the RdDM pathway, and suggest that RdDM may involve double-stranded RNAs with a 5′ overhang and the partnering between RDM12 and RDR2. © 2010 Blackwell Publishing Ltd.

Degeneration and domestication of a selfish gene in yeast: molecular evolution versus site-directed mutagenesis.

Science.gov (United States)

Koufopanou, Vassiliki; Burt, Austin

2005-07-01

VDE is a homing endonuclease gene in yeasts with an unusual evolutionary history including horizontal transmission, degeneration, and domestication into the mating-type switching locus HO. We investigate here the effects of these features on its molecular evolution. In addition, we correlate rates of evolution with results from site-directed mutagenesis studies. Functional elements have lower rates of evolution than degenerate ones and higher conservation at functionally important sites. However, functionally important and unimportant sites are equally likely to have been involved in the evolution of new function during the domestication of VDE into HO. The domestication event also indicates that VDE has been lost in some species and that VDE has been present in yeasts for more than 50 Myr.

Search Engine for Antimicrobial Resistance: A Cloud Compatible Pipeline and Web Interface for Rapidly Detecting Antimicrobial Resistance Genes Directly from Sequence Data.

Science.gov (United States)

Rowe, Will; Baker, Kate S; Verner-Jeffreys, David; Baker-Austin, Craig; Ryan, Jim J; Maskell, Duncan; Pearce, Gareth

2015-01-01

Antimicrobial resistance remains a growing and significant concern in human and veterinary medicine. Current laboratory methods for the detection and surveillance of antimicrobial resistant bacteria are limited in their effectiveness and scope. With the rapidly developing field of whole genome sequencing beginning to be utilised in clinical practice, the ability to interrogate sequencing data quickly and easily for the presence of antimicrobial resistance genes will become increasingly important and useful for informing clinical decisions. Additionally, use of such tools will provide insight into the dynamics of antimicrobial resistance genes in metagenomic samples such as those used in environmental monitoring. Here we present the Search Engine for Antimicrobial Resistance (SEAR), a pipeline and web interface for detection of horizontally acquired antimicrobial resistance genes in raw sequencing data. The pipeline provides gene information, abundance estimation and the reconstructed sequence of antimicrobial resistance genes; it also provides web links to additional information on each gene. The pipeline utilises clustering and read mapping to annotate full-length genes relative to a user-defined database. It also uses local alignment of annotated genes to a range of online databases to provide additional information. We demonstrate SEAR's application in the detection and abundance estimation of antimicrobial resistance genes in two novel environmental metagenomes, 32 human faecal microbiome datasets and 126 clinical isolates of Shigella sonnei. We have developed a pipeline that contributes to the improved capacity for antimicrobial resistance detection afforded by next generation sequencing technologies, allowing for rapid detection of antimicrobial resistance genes directly from sequencing data. SEAR uses raw sequencing data via an intuitive interface so can be run rapidly without requiring advanced bioinformatic skills or resources. Finally, we show that SEAR

Direct activation of EXPANSIN14 by LBD18 in the gene regulatory network of lateral root formation in Arabidopsis.

Science.gov (United States)

Kim, Jungmook; Lee, Han Woo

2013-02-01

Root system architecture is important for plants to adapt to a changing environment. The major determinant of the root system is lateral roots originating from the primary root. The developmental process of lateral root formation can be divided into priming, initiation, primordium development and the emergence of lateral roots, and is well characterized in Arabidopsis. The hormone auxin plays a critical role in lateral root development, and several auxin response modules involving AUXIN RESPONSE FACTORS (ARFs), transcriptional regulators of auxin-regulated genes and Aux/IAA, negative regulators of ARFs, regulate lateral root formation. The LATERAL ORGAN BOUNDARIES DOMAIN/ASYMMETRIC LEAVES2-LIKE (LBD/ASL) gene family encodes a unique class of transcription factors harbouring a conserved plant-specific lateral organ boundary domain and plays a role in lateral organ development of plants including lateral root formation. In our previous study, we showed that LBD18 stimulates lateral root formation in combination with LBD16 downstream of ARF7 and ARF19 during the auxin response. We have recently demonstrated that LBD18 activates expression of EXP14, a gene encoding the cell-wall loosening factor, by directly binding to the EXP14 promoter to promote lateral root emergence. Here we present the molecular function of LBD18 and its gene regulatory network during lateral root formation.

Genomic signatures of local directional selection in a high gene flow marine organism, the Atlantic cod (Gadus morhua)

DEFF Research Database (Denmark)

Eg Nielsen, Einar; Hansen, Jakob Hemmer; Poulsen, Nina Aagaard

2009-01-01

-associated single nucleotide polymorphisms (SNPs) for evidence of selection in local populations of Atlantic cod (Gadus morhua L.) across the species distribution. Results: Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional...... selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread...

Anti-EGFR immunonanoparticles containing IL12 and salmosin genes for targeted cancer gene therapy.

Science.gov (United States)

Kim, Jung Seok; Kang, Seong Jae; Jeong, Hwa Yeon; Kim, Min Woo; Park, Sang Il; Lee, Yeon Kyung; Kim, Hong Sung; Kim, Keun Sik; Park, Yong Serk

2016-09-01

Tumor-directed gene delivery is of major interest in the field of cancer gene therapy. Varied functionalizations of non-viral vectors have been suggested to enhance tumor targetability. In the present study, we prepared two different types of anti-EGF receptor (EGFR) immunonanoparticles containing pDNA, neutrally charged liposomes and cationic lipoplexes, for tumor-directed transfection of cancer therapeutic genes. Even though both anti-EGFR immunonanoparticles had a high binding affinity to the EGFR-positive cancer cells, the anti-EGFR immunolipoplex formulation exhibited approximately 100-fold higher transfection to the target cells than anti-EGFR immunoliposomes. The lipoplex formulation also showed a higher transfection to SK-OV-3 tumor xenografts in mice. Thus, IL12 and/or salmosin genes were loaded in the anti-EGFR immunolipoplexes and intravenously administered to mice carrying SK-OV-3 tumors. Co-transfection of IL12 and salmosin genes using anti-EGFR immunolipoplexes significantly reduced tumor growth and pulmonary metastasis. Furthermore, combinatorial treatment with doxorubicin synergistically inhibited tumor growth. These results suggest that anti-EGFR immunolipoplexes containing pDNA encoding therapeutic genes could be utilized as a gene-transfer modality for cancer gene therapy.

Ha-ras oncogene expression directed by a milk protein gene promoter: tissue specificity, hormonal regulation, and tumor induction in transgenic mice

International Nuclear Information System (INIS)

Andres, A.C.; Schoenenberger, C.A.; Groner, B.; Henninghausen, L.; LeMeur, M.; Gelinger, P.

1987-01-01

The activated human Ha-ras oncogene was subjected to the control of the promoter region of the murine whey acidic protein (Wap) gene, which is expressed in mammary epithelial cells in response to lactogenic hormones. The Wap-ras gene was stably introduced into the mouse germ line of five transgenic mice (one male and four females). Wap-ras expression was observed in the mammary glands of lactating females in two lines derived from female founders. The tissue-directed and hormone-dependent Wap expression was conferred on the Ha-ras oncogene. The signals governing Wap expression are located within 2.5 kilobases of 5' flanking sequence. The other two lines derived from female founders did not express the chimeric gene. In the line derived from the male founder the Wap-ras gene is integrated into the Y chromosome. Expression was found in the salivary gland of male animals only. After a long latency, Wap-ras-expressing mice developed tumors. The tumors arose in tissues expressing Wap-ras - i.e., mammary or salivary glands. Compared to the corresponding nonmalignant tissues, Wap-ras expression was enhanced in the tumors

Genome-wide identification of direct HBx genomic targets

KAUST Repository

Guerrieri, Francesca

2017-02-17

Background The Hepatitis B Virus (HBV) HBx regulatory protein is required for HBV replication and involved in HBV-related carcinogenesis. HBx interacts with chromatin modifying enzymes and transcription factors to modulate histone post-translational modifications and to regulate viral cccDNA transcription and cellular gene expression. Aiming to identify genes and non-coding RNAs (ncRNAs) directly targeted by HBx, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) to analyse HBV recruitment on host cell chromatin in cells replicating HBV. Results ChIP-Seq high throughput sequencing of HBx-bound fragments was used to obtain a high-resolution, unbiased, mapping of HBx binding sites across the genome in HBV replicating cells. Protein-coding genes and ncRNAs involved in cell metabolism, chromatin dynamics and cancer were enriched among HBx targets together with genes/ncRNAs known to modulate HBV replication. The direct transcriptional activation of genes/miRNAs that potentiate endocytosis (Ras-related in brain (RAB) GTPase family) and autophagy (autophagy related (ATG) genes, beclin-1, miR-33a) and the transcriptional repression of microRNAs (miR-138, miR-224, miR-576, miR-596) that directly target the HBV pgRNA and would inhibit HBV replication, contribute to HBx-mediated increase of HBV replication. Conclusions Our ChIP-Seq analysis of HBx genome wide chromatin recruitment defined the repertoire of genes and ncRNAs directly targeted by HBx and led to the identification of new mechanisms by which HBx positively regulates cccDNA transcription and HBV replication.

American Society of Gene & Cell Therapy

Science.gov (United States)

... Gene & Cell Therapy Defined Gene therapy and cell therapy are overlapping fields of biomedical research that aim to repair the direct cause of genetic diseases. Read More Gene & Cell Therapy FAQ's Read the most common questions raised by ...

A simple, flexible and efficient PCR-fusion/Gateway cloning procedure for gene fusion, site-directed mutagenesis, short sequence insertion and domain deletions and swaps

Directory of Open Access Journals (Sweden)

Etchells J Peter

2009-10-01

Full Text Available Abstract Background The progress and completion of various plant genome sequencing projects has paved the way for diverse functional genomic studies that involve cloning, modification and subsequent expression of target genes. This requires flexible and efficient procedures for generating binary vectors containing: gene fusions, variants from site-directed mutagenesis, addition of protein tags together with domain swaps and deletions. Furthermore, efficient cloning procedures, ideally high throughput, are essential for pyramiding of multiple gene constructs. Results Here, we present a simple, flexible and efficient PCR-fusion/Gateway cloning procedure for construction of binary vectors for a range of gene fusions or variants with single or multiple nucleotide substitutions, short sequence insertions, domain deletions and swaps. Results from selected applications of the procedure which include ORF fusion, introduction of Cys>Ser mutations, insertion of StrepII tag sequence and domain swaps for Arabidopsis secondary cell wall AtCesA genes are demonstrated. Conclusion The PCR-fusion/Gateway cloning procedure described provides an elegant, simple and efficient solution for a wide range of diverse and complicated cloning tasks. Through streamlined cloning of sets of gene fusions and modification variants into binary vectors for systematic functional studies of gene families, our method allows for efficient utilization of the growing sequence and expression data.

Compositional gradients in Gramineae genes

DEFF Research Database (Denmark)

Wong, Gane Ka-Shu; Wang, Jun; Tao, Lin

2002-01-01

In this study, we describe a property of Gramineae genes, and perhaps all monocot genes, that is not observed in eudicot genes. Along the direction of transcription, beginning at the junction of the 5'-UTR and the coding region, there are gradients in GC content, codon usage, and amino-acid usage...

Gene therapy prospects--intranasal delivery of therapeutic genes.

Science.gov (United States)

Podolska, Karolina; Stachurska, Anna; Hajdukiewicz, Karolina; Małecki, Maciej

2012-01-01

Gene therapy is recognized to be a novel method for the treatment of various disorders. Gene therapy strategies involve gene manipulation on broad biological processes responsible for the spreading of diseases. Cancer, monogenic diseases, vascular and infectious diseases are the main targets of gene therapy. In order to obtain valuable experimental and clinical results, sufficient gene transfer methods are required. Therapeutic genes can be administered into target tissues via gene carriers commonly defined as vectors. The retroviral, adenoviral and adeno-associated virus based vectors are most frequently used in the clinic. So far, gene preparations may be administered directly into target organs or by intravenous, intramuscular, intratumor or intranasal injections. It is common knowledge that the number of gene therapy clinical trials has rapidly increased. However, some limitations such as transfection efficiency and stable and long-term gene expression are still not resolved. Consequently, great effort is focused on the evaluation of new strategies of gene delivery. There are many expectations associated with intranasal delivery of gene preparations for the treatment of diseases. Intranasal delivery of therapeutic genes is regarded as one of the most promising forms of pulmonary gene therapy research. Gene therapy based on inhalation of gene preparations offers an alternative way for the treatment of patients suffering from such lung diseases as cystic fibrosis, alpha-1-antitrypsin defect, or cancer. Experimental and first clinical trials based on plasmid vectors or recombinant viruses have revealed that gene preparations can effectively deliver therapeutic or marker genes to the cells of the respiratory tract. The noninvasive intranasal delivery of gene preparations or conventional drugs seems to be very encouraging, although basic scientific research still has to continue.

A map of directional genetic interactions in a metazoan cell.

Science.gov (United States)

Fischer, Bernd; Sandmann, Thomas; Horn, Thomas; Billmann, Maximilian; Chaudhary, Varun; Huber, Wolfgang; Boutros, Michael

2015-03-06

Gene-gene interactions shape complex phenotypes and modify the effects of mutations during development and disease. The effects of statistical gene-gene interactions on phenotypes have been used to assign genes to functional modules. However, directional, epistatic interactions, which reflect regulatory relationships between genes, have been challenging to map at large-scale. Here, we used combinatorial RNA interference and automated single-cell phenotyping to generate a large genetic interaction map for 21 phenotypic features of Drosophila cells. We devised a method that combines genetic interactions on multiple phenotypes to reveal directional relationships. This network reconstructed the sequence of protein activities in mitosis. Moreover, it revealed that the Ras pathway interacts with the SWI/SNF chromatin-remodelling complex, an interaction that we show is conserved in human cancer cells. Our study presents a powerful approach for reconstructing directional regulatory networks and provides a resource for the interpretation of functional consequences of genetic alterations.

Toxicogenomics-based identification of mechanisms for direct immunotoxicity.

Science.gov (United States)

Shao, Jia; Katika, Madhumohan R; Schmeits, Peter C J; Hendriksen, Peter J M; van Loveren, Henk; Peijnenburg, Ad A C M; Volger, Oscar L

2013-10-01

Compounds with direct immunotoxic properties, including metals, mycotoxins, agricultural pesticides, and industrial chemicals, form potential human health risks due to exposure through food, drinking water, and the environment. Insights into the mechanisms of action are currently lacking for the majority of these direct immunotoxicants. Therefore, the present work aimed to gain insights into the molecular mechanisms underlying direct immunotoxicity. To this end, we assessed in vitro the effects of 31 test compounds on the transcriptome of the human Jurkat T-cell line. These compounds included direct immunotoxicants, immunosuppressive drugs with different mode of actions, and nonimmunotoxic control chemicals. Pathway analysis of the microarray data allowed us to identify canonical pathways and Gene Ontology processes that were transcriptionally regulated in common by immunotoxicants (1) with structural similarities, such as tributyltin chloride and tributyltin oxide that activated the retinoic acid/X receptor signaling pathway and (2) without structural similarities, such as As2O3, dibutyltin chloride, diazinon, MeHg, ochratoxin A (OTA), S9-treated OTA, S9-treated cyclophosphamide, and S9-treated benzo[a]pyrene, which activated unfolded protein response, and FTY720, lindane, and propanil, which activated the cholesterol biosynthesis pathway. In addition, processes uniquely affected by individual immunotoxicants were identified, such as the induction of Notch receptor signaling and the downregulation of acute-phase response genes by OTA. These findings were validated by quantitative real-time PCR analysis of genes involved in these processes. Our study indicated that diverse modes of action are involved in direct immunotoxicity and that a set of pathways or genes, rather than one single gene, can be used to screen compounds for direct immunotoxicity.

HTP-OligoDesigner: An Online Primer Design Tool for High-Throughput Gene Cloning and Site-Directed Mutagenesis.

Science.gov (United States)

Camilo, Cesar M; Lima, Gustavo M A; Maluf, Fernando V; Guido, Rafael V C; Polikarpov, Igor

2016-01-01

Following burgeoning genomic and transcriptomic sequencing data, biochemical and molecular biology groups worldwide are implementing high-throughput cloning and mutagenesis facilities in order to obtain a large number of soluble proteins for structural and functional characterization. Since manual primer design can be a time-consuming and error-generating step, particularly when working with hundreds of targets, the automation of primer design process becomes highly desirable. HTP-OligoDesigner was created to provide the scientific community with a simple and intuitive online primer design tool for both laboratory-scale and high-throughput projects of sequence-independent gene cloning and site-directed mutagenesis and a Tm calculator for quick queries.

FunGene: the functional gene pipeline and repository.

Science.gov (United States)

Fish, Jordan A; Chai, Benli; Wang, Qiong; Sun, Yanni; Brown, C Titus; Tiedje, James M; Cole, James R

2013-01-01

Ribosomal RNA genes have become the standard molecular markers for microbial community analysis for good reasons, including universal occurrence in cellular organisms, availability of large databases, and ease of rRNA gene region amplification and analysis. As markers, however, rRNA genes have some significant limitations. The rRNA genes are often present in multiple copies, unlike most protein-coding genes. The slow rate of change in rRNA genes means that multiple species sometimes share identical 16S rRNA gene sequences, while many more species share identical sequences in the short 16S rRNA regions commonly analyzed. In addition, the genes involved in many important processes are not distributed in a phylogenetically coherent manner, potentially due to gene loss or horizontal gene transfer. While rRNA genes remain the most commonly used markers, key genes in ecologically important pathways, e.g., those involved in carbon and nitrogen cycling, can provide important insights into community composition and function not obtainable through rRNA analysis. However, working with ecofunctional gene data requires some tools beyond those required for rRNA analysis. To address this, our Functional Gene Pipeline and Repository (FunGene; http://fungene.cme.msu.edu/) offers databases of many common ecofunctional genes and proteins, as well as integrated tools that allow researchers to browse these collections and choose subsets for further analysis, build phylogenetic trees, test primers and probes for coverage, and download aligned sequences. Additional FunGene tools are specialized to process coding gene amplicon data. For example, FrameBot produces frameshift-corrected protein and DNA sequences from raw reads while finding the most closely related protein reference sequence. These tools can help provide better insight into microbial communities by directly studying key genes involved in important ecological processes.

FunGene: the Functional Gene Pipeline and Repository

Directory of Open Access Journals (Sweden)

Jordan A. Fish

2013-10-01

Full Text Available Ribosomal RNA genes have become the standard molecular markers for microbial community analysis for good reasons, including universal occurrence in cellular organisms, availability of large databases, and ease of rRNA gene region amplification and analysis. As markers, however, rRNA genes have some significant limitations. The rRNA genes are often present in multiple copies, unlike most protein-coding genes. The slow rate of change in rRNA genes means that multiple species sometimes share identical 16S rRNA gene sequences, while many more species share identical sequences in the short 16S rRNA regions commonly analyzed. In addition, the genes involved in many important processes are not distributed in a phylogenetically coherent manner, potentially due to gene loss or horizontal gene transfer.While rRNA genes remain the most commonly used markers, key genes in ecologically important pathways, e.g., those involved in carbon and nitrogen cycling, can provide important insights into community composition and function not obtainable through rRNA analysis. However, working with ecofunctional gene data requires some tools beyond those required for rRNA analysis. To address this, our Functional Gene Pipeline and Repository (FunGene; http://fungene.cme.msu.edu/ offers databases of many common ecofunctional genes and proteins, as well as integrated tools that allow researchers to browse these collections and choose subsets for further analysis, build phylogenetic trees, test primers and probes for coverage, and download aligned sequences. Additional FunGene tools are specialized to process coding gene amplicon data. For example, FrameBot produces frameshift-corrected protein and DNA sequences from raw reads while finding the most closely related protein reference sequence. These tools can help provide better insight into microbial communities by directly studying key genes involved in important ecological processes.

SOX9 governs differentiation stage-specific gene expression in growth plate chondrocytes via direct concomitant transactivation and repression.

Directory of Open Access Journals (Sweden)

Victor Y L Leung

2011-11-01

Full Text Available Cartilage and endochondral bone development require SOX9 activity to regulate chondrogenesis, chondrocyte proliferation, and transition to a non-mitotic hypertrophic state. The restricted and reciprocal expression of the collagen X gene, Col10a1, in hypertrophic chondrocytes and Sox9 in immature chondrocytes epitomise the precise spatiotemporal control of gene expression as chondrocytes progress through phases of differentiation, but how this is achieved is not clear. Here, we have identified a regulatory element upstream of Col10a1 that enhances its expression in hypertrophic chondrocytes in vivo. In immature chondrocytes, where Col10a1 is not expressed, SOX9 interacts with a conserved sequence within this element that is analogous to that within the intronic enhancer of the collagen II gene Col2a1, the known transactivation target of SOX9. By analysing a series of Col10a1 reporter genes in transgenic mice, we show that the SOX9 binding consensus in this element is required to repress expression of the transgene in non-hypertrophic chondrocytes. Forced ectopic Sox9 expression in hypertrophic chondrocytes in vitro and in mice resulted in down-regulation of Col10a1. Mutation of a binding consensus motif for GLI transcription factors, which are the effectors of Indian hedgehog signaling, close to the SOX9 site in the Col10a1 regulatory element, also derepressed transgene expression in non-hypertrophic chondrocytes. GLI2 and GLI3 bound to the Col10a1 regulatory element but not to the enhancer of Col2a1. In addition to Col10a1, paired SOX9-GLI binding motifs are present in the conserved non-coding regions of several genes that are preferentially expressed in hypertrophic chondrocytes and the occurrence of pairing is unlikely to be by chance. We propose a regulatory paradigm whereby direct concomitant positive and negative transcriptional control by SOX9 ensures differentiation phase-specific gene expression in chondrocytes. Discrimination between

Directed evolution induces tributyrin hydrolysis in a virulence factor of Xylella fastidiosa using a duplicated gene as a template.

Science.gov (United States)

Gouran, Hossein; Chakraborty, Sandeep; Rao, Basuthkar J; Asgeirsson, Bjarni; Dandekar, Abhaya

2014-01-01

Duplication of genes is one of the preferred ways for natural selection to add advantageous functionality to the genome without having to reinvent the wheel with respect to catalytic efficiency and protein stability. The duplicated secretory virulence factors of Xylella fastidiosa (LesA, LesB and LesC), implicated in Pierce's disease of grape and citrus variegated chlorosis of citrus species, epitomizes the positive selection pressures exerted on advantageous genes in such pathogens. A deeper insight into the evolution of these lipases/esterases is essential to develop resistance mechanisms in transgenic plants. Directed evolution, an attempt to accelerate the evolutionary steps in the laboratory, is inherently simple when targeted for loss of function. A bigger challenge is to specify mutations that endow a new function, such as a lost functionality in a duplicated gene. Previously, we have proposed a method for enumerating candidates for mutations intended to transfer the functionality of one protein into another related protein based on the spatial and electrostatic properties of the active site residues (DECAAF). In the current work, we present in vivo validation of DECAAF by inducing tributyrin hydrolysis in LesB based on the active site similarity to LesA. The structures of these proteins have been modeled using RaptorX based on the closely related LipA protein from Xanthomonas oryzae. These mutations replicate the spatial and electrostatic conformation of LesA in the modeled structure of the mutant LesB as well, providing in silico validation before proceeding to the laborious in vivo work. Such focused mutations allows one to dissect the relevance of the duplicated genes in finer detail as compared to gene knockouts, since they do not interfere with other moonlighting functions, protein expression levels or protein-protein interaction.

Direct Detection and Differentiation of Pathogenic Leptospira Species Using a Multi-Gene Targeted Real Time PCR Approach

Science.gov (United States)

Ferreira, Ana Sofia; Costa, Pedro; Rocha, Teresa; Amaro, Ana; Vieira, Maria Luísa; Ahmed, Ahmed; Thompson, Gertrude; Hartskeerl, Rudy A.; Inácio, João

2014-01-01

Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal β-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis. PMID:25398140

GeneTopics - interpretation of gene sets via literature-driven topic models

Science.gov (United States)

2013-01-01

Background Annotation of a set of genes is often accomplished through comparison to a library of labelled gene sets such as biological processes or canonical pathways. However, this approach might fail if the employed libraries are not up to date with the latest research, don't capture relevant biological themes or are curated at a different level of granularity than is required to appropriately analyze the input gene set. At the same time, the vast biomedical literature offers an unstructured repository of the latest research findings that can be tapped to provide thematic sub-groupings for any input gene set. Methods Our proposed method relies on a gene-specific text corpus and extracts commonalities between documents in an unsupervised manner using a topic model approach. We automatically determine the number of topics summarizing the corpus and calculate a gene relevancy score for each topic allowing us to eliminate non-specific topics. As a result we obtain a set of literature topics in which each topic is associated with a subset of the input genes providing directly interpretable keywords and corresponding documents for literature research. Results We validate our method based on labelled gene sets from the KEGG metabolic pathway collection and the genetic association database (GAD) and show that the approach is able to detect topics consistent with the labelled annotation. Furthermore, we discuss the results on three different types of experimentally derived gene sets, (1) differentially expressed genes from a cardiac hypertrophy experiment in mice, (2) altered transcript abundance in human pancreatic beta cells, and (3) genes implicated by GWA studies to be associated with metabolite levels in a healthy population. In all three cases, we are able to replicate findings from the original papers in a quick and semi-automated manner. Conclusions Our approach provides a novel way of automatically generating meaningful annotations for gene sets that are directly

Large scale gene expression meta-analysis reveals tissue-specific, sex-biased gene expression in humans

Directory of Open Access Journals (Sweden)

Benjamin Mayne

2016-10-01

Full Text Available The severity and prevalence of many diseases are known to differ between the sexes. Organ specific sex-biased gene expression may underpin these and other sexually dimorphic traits. To further our understanding of sex differences in transcriptional regulation, we performed meta-analyses of sex biased gene expression in multiple human tissues. We analysed 22 publicly available human gene expression microarray data sets including over 2500 samples from 15 different tissues and 9 different organs. Briefly, by using an inverse-variance method we determined the effect size difference of gene expression between males and females. We found the greatest sex differences in gene expression in the brain, specifically in the anterior cingulate cortex, (1818 genes, followed by the heart (375 genes, kidney (224 genes, colon (218 genes and thyroid (163 genes. More interestingly, we found different parts of the brain with varying numbers and identity of sex-biased genes, indicating that specific cortical regions may influence sexually dimorphic traits. The majority of sex-biased genes in other tissues such as the bladder, liver, lungs and pancreas were on the sex chromosomes or involved in sex hormone production. On average in each tissue, 32% of autosomal genes that were expressed in a sex-biased fashion contained androgen or estrogen hormone response elements. Interestingly, across all tissues, we found approximately two-thirds of autosomal genes that were sex-biased were not under direct influence of sex hormones. To our knowledge this is the largest analysis of sex-biased gene expression in human tissues to date. We identified many sex-biased genes that were not under the direct influence of sex chromosome genes or sex hormones. These may provide targets for future development of sex-specific treatments for diseases.

Multiple Site-Directed and Saturation Mutagenesis by the Patch Cloning Method.

Science.gov (United States)

Taniguchi, Naohiro; Murakami, Hiroshi

2017-01-01

Constructing protein-coding genes with desired mutations is a basic step for protein engineering. Herein, we describe a multiple site-directed and saturation mutagenesis method, termed MUPAC. This method has been used to introduce multiple site-directed mutations in the green fluorescent protein gene and in the moloney murine leukemia virus reverse transcriptase gene. Moreover, this method was also successfully used to introduce randomized codons at five desired positions in the green fluorescent protein gene, and for simple DNA assembly for cloning.

Site-directed mutagenesis of the foot-and-mouth disease virus RNA-polymerase gene

International Nuclear Information System (INIS)

Brindeiro, R.M.; Soares, M.A.; Vianna, A.L.M.; Pontes, O.H.A. de; Pacheco, A.B.F.; Almeida, D.F. de; Tanuri, A.

1991-01-01

The foot-and-mouth disease virus RNA-polymerase gene was mutagenised in its active site. Pst I digestion of the polymerase gene (cDNA) generated a 790 bp fragment containing the critical sequence. This fragment was subcloned in M13mp8 for mutagenesis method. The polymerase gene was then reconstructed and subcloned in pUC19. These mutants will be used to study the enzyme structure and activity and to develop intracellular immunization assays in eukaryotic cells. (author)

Human γ-globin genes silenced independently of other genes in the β-globin locus.

NARCIS (Netherlands)

N.O. Dillon (Niall); F.G. Grosveld (Frank)

1991-01-01

textabstractErythropoiesis during human development is characterized by switches in expression of beta-like globin genes during the transition from the embryonic through fetal to adult stages. Activation and high-level expression of the genes is directed by the locus control region (LCR), located 5'

Gene-gene interactions of IRF5, STAT4, IKZF1 and ETS1 in systemic lupus erythematosus.

Science.gov (United States)

Dang, J; Shan, S; Li, J; Zhao, H; Xin, Q; Liu, Y; Bian, X; Liu, Q

2014-06-01

Interferon (IFN) activation signaling and T helper 17 (Th17)-cell/B-cell regulation play a critical role in the pathogenesis of systemic lupus erythematosus (SLE). Several studies have provided convincing evidence that polymorphisms in IRF5, STAT4, IKZF1 and ETS1 from these pathways may be involved in SLE by affecting gene expression or epistasis. We analyzed the genetic interaction in known SLE susceptibility loci from the four genes in northern Han Chinese. A total of 946 northern Han Chinese participated in this study (370 unrelated SLE patients and 576 healthy controls). Subjects underwent genotyping for the single-nucleotide polymorphisms (SNPs) rs2004640 in IRF5, rs7574865 in STAT4, rs4917014 in IKZF1 and rs1128334 in ETS1 by use of a TaqMan SNP genotyping assay and direct sequencing. Gene-gene interaction analysis involved direct counting, multifactor dimensionality reduction (MDR) and linear regression analysis. SLE patients and controls differed in allele frequencies of rs7574865, rs1128334 (P < 0.001) and rs4917014 (P < 0.01). Direct counting revealed that the frequency of risk homozygote combinations was higher for SLE patients than controls (P < 0.01). Furthermore, 2-, 3- and 4-way gene-gene epistasis in SLE was confirmed by parametric methods and MDR analysis. Gene expression analysis partially supported the findings. Our study confirmed the association of the IFN pathway or Th17/B-cells and the pathogenesis of SLE, and gene-gene interaction in this pathway may increase the risk of SLE. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

From gene engineering to gene modulation and manipulation: can we prevent or detect gene doping in sports?

Science.gov (United States)

Fischetto, Giuseppe; Bermon, Stéphane

2013-10-01

During the last 2 decades, progress in deciphering the human gene map as well as the discovery of specific defective genes encoding particular proteins in some serious human diseases have resulted in attempts to treat sick patients with gene therapy. There has been considerable focus on human recombinant proteins which were gene-engineered and produced in vitro (insulin, growth hormone, insulin-like growth factor-1, erythropoietin). Unfortunately, these substances and methods also became improper tools for unscrupulous athletes. Biomedical research has focused on the possible direct insertion of gene material into the body, in order to replace some defective genes in vivo and/or to promote long-lasting endogenous synthesis of deficient proteins. Theoretically, diabetes, anaemia, muscular dystrophies, immune deficiency, cardiovascular diseases and numerous other illnesses could benefit from such innovative biomedical research, though much work remains to be done. Considering recent findings linking specific genotypes and physical performance, it is tempting to submit the young athletic population to genetic screening or, alternatively, to artificial gene expression modulation. Much research is already being conducted in order to achieve a safe transfer of genetic material to humans. This is of critical importance since uncontrolled production of the specifically coded protein, with serious secondary adverse effects (polycythaemia, acute cardiovascular problems, cancer, etc.), could occur. Other unpredictable reactions (immunogenicity of vectors or DNA-vector complex, autoimmune anaemia, production of wild genetic material) also remain possible at the individual level. Some new substances (myostatin blockers or anti-myostatin antibodies), although not gene material, might represent a useful and well-tolerated treatment to prevent progression of muscular dystrophies. Similarly, other molecules, in the roles of gene or metabolic activators [5-aminoimidazole-4

How does the extracellular matrix direct gene expression

Energy Technology Data Exchange (ETDEWEB)

Bissell, M J; Hall, H G; Parry, G

1982-01-01

Based on the existing literature, a model is presented that postulates a ''dynamic reciprocity'' between the extracellular matrix (ECM) on the one hand and the cytoskeleton and the nuclear matrix on the other hand. The ECM is postulated to exert physical and chemical influences on the geometry and the biochemistry of the cell via transmembrane receptors so as to alter the pattern of gene expression by changing the association of the cytoskeleton with mRNA and the interaction of the chromatin with the nuclear matrix. This, in turn, would affect the ECM, which would affect the cell.

A unique nuclear receptor direct repeat 17 (DR17) is present within the upstream region of Schistosoma mansoni female-specific p14 gene

International Nuclear Information System (INIS)

Fantappie, Marcelo Rosado; Furtado, Daniel Rodrigues; Rumjanek, Franklin David; LoVerde, Philip T.

2008-01-01

The eggs produced by sexually mature female Schistosma mansoni are responsible for the pathogenesis of the disease. The eggshell precursor gene p14 is expressed only in the vitelline cells of sexually mature female worms in response to a yet unidentified male stimulus. Herein, we report the identification of a novel nuclear receptor response element in the upstream region of the p14 gene. This element contains the canonical hexameric DNA core motif, 5'-PuGGTCA, composed of an atypically spaced direct repeat (DR17). Schistosome nuclear receptors SmRXR1 and SmNR1 specifically bound to the p14-DR17 element as a heterodimer. SmRXR1, but not SmNR1, bound to the motif as a monomer. Introduction of mutations in the TCA core sequence completely abolished the binding by SmRXR1/SmNR1 heterodimer. This finding supports our hypothesis that the expression of Schistosoma mansonip14 gene is regulated through the nuclear receptor signaling pathway

Apoptosis Gene Information System--AGIS.

Science.gov (United States)

Sakharkar, Kishore R; Clement, Marie V; Chow, Vincent T K; Pervaiz, Shazib

2006-05-01

Genes implicated in apoptosis have great relevance to biology, medicine and oncology. Here, we describe a unique resource, Apoptosis Gene Information System (AGIS) that provides data for over 2400 genes involved directly or indirectly, in apoptotic pathways of more than 350 different organisms. The organization of this information system is based on the principle of one-gene, one record. AGIS will be updated on a six monthly basis as new information becomes available. AGIS can be accessed at: http://www.cellfate.org/AGIS/.

Direct Activation of Amidohydrolase Domain-Containing 1 Gene by Thyroid Hormone Implicates a Role in the Formation of Adult Intestinal Stem Cells During Xenopus Metamorphosis.

Science.gov (United States)

Okada, Morihiro; Miller, Thomas C; Fu, Liezhen; Shi, Yun-Bo

2015-09-01

The T3-dependent anuran metamorphosis resembles postembryonic development in mammals, the period around birth when plasma T3 levels peak. In particular, the remodeling of the intestine during metamorphosis mimics neonatal intestinal maturation in mammals when the adult intestinal epithelial self-renewing system is established. We have been using intestinal metamorphosis to investigate how the organ-specific adult stem cells are formed during vertebrate development. Early studies in Xenopus laevis have shown that this process involves complete degeneration of the larval epithelium and de novo formation of adult stem cells. A tissue-specific microarray analysis of intestinal gene expression during Xenopus laevis metamorphosis has identified a number of candidate stem cell genes. Here we have carried out detailed analyses of one such gene, amidohydrolase domain containing 1 (AMDHD1) gene, which encodes an enzyme in the histidine catabolic pathway. We show that AMDHD1 is exclusively expressed in the proliferating adult epithelial stem cells during metamorphosis with little expression in other intestinal tissues. We further provide evidence that T3 activates AMDHD1 gene expression directly at the transcription level through T3 receptor binding to the AMDHD1 gene in the intestine. In addition, we have reported earlier that histidine ammonia-lyase gene, another gene in histidine catabolic pathway, is similarly regulated by T3 in the intestine. These results together suggest that histidine catabolism plays a critical role in the formation and/or proliferation of adult intestinal stem cells during metamorphosis.

Subgenomic Diversity Patterns Caused by Directional Selection in Bread Wheat Gene Pools

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Kai Voss-Fels

2015-07-01

Full Text Available Genetic diversity represents the fundamental key to breeding success, providing the basis for breeders to select varieties with constantly improving yield performance. On the other hand, strong selection during domestication and breeding have eliminated considerable genetic diversity in the breeding pools of major crops, causing erosion of genetic potential for adaptation to emerging challenges like climate change. High-throughput genomic technologies can address this dilemma by providing detailed knowledge to characterize and replenish genetic diversity in breeding programs. In hexaploid bread wheat ( L., the staple food for 35% of the world’s population, bottlenecks during allopolyploidisation followed by strong artificial selection have considerably narrowed diversity to the extent that yields in many regions appear to be unexpectedly stagnating. In this study, we used a 90,000 single nucleotide polymorphism (SNP wheat genotyping array to assay high-frequency, polymorphic SNP markers in 460 accessions representing different phenological diversity groups from Asian, Australian, European, and North American bread wheat breeding materials. Detailed analysis of subgroup diversity at the chromosome and subgenome scale revealed highly distinct patterns of conserved linkage disequilibrium between different gene pools. The data enable identification of genome regions in most need of rejuvenation with novel diversity and provide a high-resolution molecular basis for genomic-assisted introgression of new variation into chromosome segments surrounding directionally selected metaloci conferring important adaptation and quality traits.

Efficient in vivo gene transfer to xenotransplanted human skin by lentivirus-mediated, but not by AAV-directed, gene delivery

DEFF Research Database (Denmark)

Jakobsen, Maria Vad; Askou, Anne Louise; Dokkedahl, Karin Stenderup

skin graft, and firefly luciferase expression was observed primarily in neighboring tissue beneath or surrounding the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin...... graft only. The study demonstrates limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo....

Nano-scale gene delivery systems; current technology, obstacles, and future directions.

Science.gov (United States)

Garcia-Guerra, Antonio; Dunwell, Thomas L; Trigueros, Sonia

2018-01-07

Within the different applications of nanomedicine currently being developed, nano-gene delivery is appearing as an exciting new technique with the possibility to overcome recognised hurdles and fulfill several biological and medical needs. The central component of all delivery systems is the requirement for the delivery of genetic material into cells, and for them to eventually reside in the nucleus where their desired function will be exposed. However, genetic material does not passively enter cells; thus, a delivery system is necessary. The emerging field of nano-gene delivery exploits the use of new materials and the properties that arise at the nanometre-scale to produce delivery vectors that can effectively deliver genetic material into a variety of different types of cells. The novel physicochemical properties of the new delivery vectors can be used to address the current challenges existing in nucleic acid delivery in vitro and in vivo. While there is a growing interest in nanostructure-based gene delivery, the field is still in its infancy, and there is yet much to discover about nanostructures and their physicochemical properties in a biological context. We carry out an organized and focused search of bibliographic databases. Our results suggest that despite new breakthroughs in nanostructure synthesis and advanced characterization techniques, we still face many barriers in producing highly efficient and non-toxic delivery systems. In this review, we overview the types of systems currently used for clinical and biomedical research applications along with their advantages and disadvantages, as well as discussing barriers that arise from nano-scale interactions with biological material. In conclusion, we hope that by bringing the far reaching multidisciplinary nature of nano-gene delivery to light, new targeted nanotechnology-bases strategies are developed to overcome the major challenges covered in this review. Copyright© Bentham Science Publishers; For

PCR-based detection of gene transfer vectors: application to gene doping surveillance.

Science.gov (United States)

Perez, Irene C; Le Guiner, Caroline; Ni, Weiyi; Lyles, Jennifer; Moullier, Philippe; Snyder, Richard O

2013-12-01

Athletes who illicitly use drugs to enhance their athletic performance are at risk of being banned from sports competitions. Consequently, some athletes may seek new doping methods that they expect to be capable of circumventing detection. With advances in gene transfer vector design and therapeutic gene transfer, and demonstrations of safety and therapeutic benefit in humans, there is an increased probability of the pursuit of gene doping by athletes. In anticipation of the potential for gene doping, assays have been established to directly detect complementary DNA of genes that are top candidates for use in doping, as well as vector control elements. The development of molecular assays that are capable of exposing gene doping in sports can serve as a deterrent and may also identify athletes who have illicitly used gene transfer for performance enhancement. PCR-based methods to detect foreign DNA with high reliability, sensitivity, and specificity include TaqMan real-time PCR, nested PCR, and internal threshold control PCR.

Gene-Environment Interactions in Genome-Wide Association Studies: Current Approaches and New Directions

Science.gov (United States)

Winham, Stacey J.; Biernacka, Joanna M.

2013-01-01

Background: Complex psychiatric traits have long been thought to be the result of a combination of genetic and environmental factors, and gene-environment interactions are thought to play a crucial role in behavioral phenotypes and the susceptibility and progression of psychiatric disorders. Candidate gene studies to investigate hypothesized…

Development of chimeric gene promoters responsive to hypoxia and ionizing radiation

International Nuclear Information System (INIS)

Zheng Aiqing; Yu Jinming

2004-01-01

The authors describe two systems that make use of gene-directed enzyme prodrug therapy, regulated by radiation or hypoxic-responsive promoters. The use of treatment-, condition- or tumor-specific promoters to control gene-directed enzyme prodrug therapy is one such method for targeting gene expression to the tumor. The development of such strategies that achieve tumor targeted expression of genes via selective promoters will enable improved specificity and targeting thereby addressing one of the major limitations of cancer gene therapy

Targeted in vitro and in vivo gene transfer into T Lymphocytes: potential of direct inhibition of allo-immune activation

Directory of Open Access Journals (Sweden)

Mehra Mandeep R

2006-11-01

Full Text Available Abstract Background Successful inhibition of alloimmune activation in organ transplantation remains one of the key events in achieving a long-term graft survival. Since T lymphocytes are largely responsible for alloimmune activation, targeted gene transfer of gene of cyclin kinase inhibitor p21 into T cells might inhibit their aberrant proliferation. A number of strategies using either adenoviral or lentiviral vectors linked to mono or bispecific antibodies directed against T cell surface markers/cytokines did not yield the desired results. Therefore, this study was designed to test if a CD3promoter-p21 chimeric construct would in vitro and in vivo transfer p21 gene to T lymphocytes and result in inhibition of proliferation. CD3 promoter-p21 chimeric constructs were prepared with p21 in the sense and antisense orientation. For in vitro studies EL4-IL-2 thyoma cells were used and for in vivo studies CD3p21 sense and antisense plasmid DNA was injected intramuscularly in mice. Lymphocyte proliferation was quantified by 3H-thymidine uptake assay; IL-2 mRNA expression was studied by RT-PCR and using Real Time PCR assay, we monitored the CD3, p21, TNF-α and IFN-γ mRNA expression. Results Transfection of CD3p21 sense and antisense in mouse thyoma cell line (EL4-IL-2 resulted in modulation of mitogen-induced proliferation. The intramuscular injection of CD3p21 sense and antisense plasmid DNA into mice also modulated lymphocyte proliferation and mRNA expression of pro-inflammatory cytokines. Conclusion These results demonstrate a novel strategy of in vitro and in vivo transfer of p21 gene to T cells using CD3-promoter to achieve targeted inhibition of lymphocyte proliferation and immune activation.

A centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria.

Science.gov (United States)

Choi, Goro; Jung, Jae Hwan; Park, Byung Hyun; Oh, Seung Jun; Seo, Ji Hyun; Choi, Jong Seob; Kim, Do Hyun; Seo, Tae Seok

2016-06-21

In this study, we developed a centrifugal direct recombinase polymerase amplification (direct-RPA) microdevice for multiplex and real-time identification of food poisoning bacteria contaminated milk samples. The microdevice was designed to contain identical triplicate functional units and each unit has four reaction chambers, thereby making it possible to perform twelve direct-RPA reactions simultaneously. The integrated microdevice consisted of two layers: RPA reagents were injected in the top layer, while spiked milk samples with food poisoning bacteria were loaded into sample reservoirs in the bottom layer. For multiplex bacterial detection, the target gene-specific primers and probes were dried in each reaction chamber. The introduced samples and reagents could be equally aliquoted and dispensed into each reaction chamber by centrifugal force, and then the multiplex direct-RPA reaction was executed. The target genes of bacteria spiked in milk could be amplified at 39 °C without a DNA extraction step by using the direct-RPA cocktails, which were a combination of a direct PCR buffer and RPA enzymes. As the target gene amplification proceeded, the increased fluorescence signals coming from the reaction chambers were recorded in real-time at an interval of 2 min. The entire process, including the sample distribution, the direct-RPA reaction, and the real-time analysis, was accomplished with a custom-made portable genetic analyzer and a miniaturized optical detector. Monoplex, duplex, and triplex food poisoning bacteria (Salmonella enterica, Escherichia coli O157:H7, and Vibrio parahaemolyticus) detection was successfully performed with a detection sensitivity of 4 cells per 3.2 μL of milk samples within 30 min. By implementing the direct-PRA on the miniaturized centrifugal microsystem, the on-site food poisoning bacteria analysis would be feasible with high speed, sensitivity, and multiplicity.

Tumor-directed gene therapy in mice using a composite nonviral gene delivery system consisting of the piggyBac transposon and polyethylenimine

International Nuclear Information System (INIS)

Kang, Yu; Zhang, Xiaoyan; Jiang, Wei; Wu, Chaoqun; Chen, Chunmei; Zheng, Yufang; Gu, Jianren; Xu, Congjian

2009-01-01

Compared with viral vectors, nonviral vectors are less immunogenic, more stable, safer and easier to replication for application in cancer gene therapy. However, nonviral gene delivery system has not been extensively used because of the low transfection efficiency and the short transgene expression, especially in vivo. It is desirable to develop a nonviral gene delivery system that can support stable genomic integration and persistent gene expression in vivo. Here, we used a composite nonviral gene delivery system consisting of the piggyBac (PB) transposon and polyethylenimine (PEI) for long-term transgene expression in mouse ovarian tumors. A recombinant plasmid PB [Act-RFP, HSV-tk] encoding both the herpes simplex thymidine kinase (HSV-tk) and the monomeric red fluorescent protein (mRFP1) under PB transposon elements was constructed. This plasmid and the PBase plasmid were injected into ovarian cancer tumor xenografts in mice by in vivo PEI system. The antitumor effects of HSV-tk/ganciclovir (GCV) system were observed after intraperitoneal injection of GCV. Histological analysis and TUNEL assay were performed on the cryostat sections of the tumor tissue. Plasmid construction was confirmed by PCR analysis combined with restrictive enzyme digestion. mRFP1 expression could be visualized three weeks after the last transfection of pPB/TK under fluorescence microscopy. After GCV admission, the tumor volume of PB/TK group was significantly reduced and the tumor inhibitory rate was 81.96% contrasted against the 43.07% in the TK group. Histological analysis showed that there were extensive necrosis and lymphocytes infiltration in the tumor tissue of the PB/TK group but limited in the tissue of control group. TUNEL assays suggested that the transfected cells were undergoing apoptosis after GCV admission in vivo. Our results show that the nonviral gene delivery system coupling PB transposon with PEI can be used as an efficient tool for gene therapy in ovarian cancer

Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua

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Mittelholzer Christian

2009-12-01

Full Text Available Abstract Background Marine fishes have been shown to display low levels of genetic structuring and associated high levels of gene flow, suggesting shallow evolutionary trajectories and, possibly, limited or lacking adaptive divergence among local populations. We investigated variation in 98 gene-associated single nucleotide polymorphisms (SNPs for evidence of selection in local populations of Atlantic cod (Gadus morhua L. across the species distribution. Results Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread and complex, i.e. outlier loci were generally not only associated with one of a few divergent local populations. Even on a limited geographical scale between the proximate North Sea and Baltic Sea populations four loci displayed evidence of adaptive evolution. Temporal genome scan analysis applied to DNA from archived otoliths from a Faeroese population demonstrated stability of the intra-population variation over 24 years. An exploratory landscape genetic analysis was used to elucidate potential effects of the most likely environmental factors responsible for the signatures of local adaptation. We found that genetic variation at several of the outlier loci was better correlated with temperature and/or salinity conditions at spawning grounds at spawning time than with geographic distance per se. Conclusion These findings illustrate that adaptive population divergence may indeed be prevalent despite seemingly high levels of gene flow, as found in most marine fishes. Thus, results have important implications for our understanding of the interplay of

The metabolic regulator CodY links L. monocytogenes metabolism to virulence by directly activating the virulence regulatory gene, prfA

Science.gov (United States)

Lobel, Lior; Sigal, Nadejda; Borovok, Ilya; Belitsky, Boris R.; Sonenshein, Abraham L.; Herskovits, Anat A.

2015-01-01

Summary Metabolic adaptations are critical to the ability of bacterial pathogens to grow within host cells and are normally preceded by sensing of host-specific metabolic signals, which in turn can influence the pathogen's virulence state. Previously, we reported that the intracellular bacterial pathogen Listeria monocytogenes responds to low availability of branched-chain amino acids (BCAA) within mammalian cells by up-regulating both BCAA biosynthesis and virulence genes. The induction of virulence genes required the BCAA-responsive transcription regulator, CodY, but the molecular mechanism governing this mode of regulation was unclear. In this report, we demonstrate that CodY directly binds the coding sequence of the L. monocytogenes master virulence activator gene, prfA, 15 nt downstream of its start codon, and that this binding results in up-regulation of prfA transcription specifically under low concentrations of BCAA. Mutating this site abolished CodY binding and reduced prfA transcription in macrophages, and attenuated bacterial virulence in mice. Notably, the mutated binding site did not alter prfA transcription or PrfA activity under other conditions that are known to activate PrfA, such as during growth in the presence of glucose-1-phosphate. This study highlights the tight crosstalk between L. monocytogenes metabolism and virulence' while revealing novel features of CodY-mediated regulation. PMID:25430920

Direct sequencing of FAH gene in Pakistani tyrosinemia type 1 families reveals a novel mutation.

Science.gov (United States)

Ijaz, Sadaqat; Zahoor, Muhammad Yasir; Imran, Muhammad; Afzal, Sibtain; Bhinder, Munir A; Ullah, Ihsan; Cheema, Huma Arshad; Ramzan, Khushnooda; Shehzad, Wasim

2016-03-01

Hereditary tyrosinemia type 1 (HT1) is a rare inborn error of tyrosine catabolism with a worldwide prevalence of one out of 100,000 live births. HT1 is clinically characterized by hepatic and renal dysfunction resulting from the deficiency of fumarylacetoacetate hydrolase (FAH) enzyme, caused by recessive mutations in the FAH gene. We present here the first report on identification of FAH mutations in HT1 patients from Pakistan with a novel one. Three Pakistani families, each having one child affected with HT1, were enrolled over a period of 1.5 years. Two of the affected children had died as they were presented late with acute form. All regions of the FAH gene spanning exons and splicing sites were amplified by polymerase chain reaction (PCR) and mutation analysis was carried out by direct sequencing. Results of sequencing were confirmed by restriction fragment length polymorphism (PCR-RFLP) analysis. Three different FAH mutations, one in each family, were found to co-segregate with the disease phenotype. Two of these FAH mutations have been known (c.192G>T and c.1062+5G>A [IVS12+5G>A]), while c.67T>C (p.Ser23Pro) was a novel mutation. The novel variant was not detected in any of 120 chromosomes from normal ethnically matched individuals. Most of the HT1 patients die before they present to hospitals in Pakistan, as is indicated by enrollment of only three families in 1.5 years. Most of those with late clinical presentation do not survive due to delayed diagnosis followed by untimely treatment. This tragic condition advocates the establishment of expanded newborn screening program for HT1 within Pakistan.

Evolution of genetic architecture under directional selection.

Science.gov (United States)

Hansen, Thomas F; Alvarez-Castro, José M; Carter, Ashley J R; Hermisson, Joachim; Wagner, Günter P

2006-08-01

We investigate the multilinear epistatic model under mutation-limited directional selection. We confirm previous results that only directional epistasis, in which genes on average reinforce or diminish each other's effects, contribute to the initial evolution of mutational effects. Thus, either canalization or decanalization can occur under directional selection, depending on whether positive or negative epistasis is prevalent. We then focus on the evolution of the epistatic coefficients themselves. In the absence of higher-order epistasis, positive pairwise epistasis will tend to weaken relative to additive effects, while negative pairwise epistasis will tend to become strengthened. Positive third-order epistasis will counteract these effects, while negative third-order epistasis will reinforce them. More generally, gene interactions of all orders have an inherent tendency for negative changes under directional selection, which can only be modified by higher-order directional epistasis. We identify three types of nonadditive quasi-equilibrium architectures that, although not strictly stable, can be maintained for an extended time: (1) nondirectional epistatic architectures; (2) canalized architectures with strong epistasis; and (3) near-additive architectures in which additive effects keep increasing relative to epistasis.

Gene Ontology and KEGG Enrichment Analyses of Genes Related to Age-Related Macular Degeneration

Directory of Open Access Journals (Sweden)

Jian Zhang

2014-01-01

Full Text Available Identifying disease genes is one of the most important topics in biomedicine and may facilitate studies on the mechanisms underlying disease. Age-related macular degeneration (AMD is a serious eye disease; it typically affects older adults and results in a loss of vision due to retina damage. In this study, we attempt to develop an effective method for distinguishing AMD-related genes. Gene ontology and KEGG enrichment analyses of known AMD-related genes were performed, and a classification system was established. In detail, each gene was encoded into a vector by extracting enrichment scores of the gene set, including it and its direct neighbors in STRING, and gene ontology terms or KEGG pathways. Then certain feature-selection methods, including minimum redundancy maximum relevance and incremental feature selection, were adopted to extract key features for the classification system. As a result, 720 GO terms and 11 KEGG pathways were deemed the most important factors for predicting AMD-related genes.

Visual gene developer: a fully programmable bioinformatics software for synthetic gene optimization

Directory of Open Access Journals (Sweden)

McDonald Karen

2011-08-01

Full Text Available Abstract Background Direct gene synthesis is becoming more popular owing to decreases in gene synthesis pricing. Compared with using natural genes, gene synthesis provides a good opportunity to optimize gene sequence for specific applications. In order to facilitate gene optimization, we have developed a stand-alone software called Visual Gene Developer. Results The software not only provides general functions for gene analysis and optimization along with an interactive user-friendly interface, but also includes unique features such as programming capability, dedicated mRNA secondary structure prediction, artificial neural network modeling, network & multi-threaded computing, and user-accessible programming modules. The software allows a user to analyze and optimize a sequence using main menu functions or specialized module windows. Alternatively, gene optimization can be initiated by designing a gene construct and configuring an optimization strategy. A user can choose several predefined or user-defined algorithms to design a complicated strategy. The software provides expandable functionality as platform software supporting module development using popular script languages such as VBScript and JScript in the software programming environment. Conclusion Visual Gene Developer is useful for both researchers who want to quickly analyze and optimize genes, and those who are interested in developing and testing new algorithms in bioinformatics. The software is available for free download at http://www.visualgenedeveloper.net.

Estrogen regulation of chicken riboflavin carrier protein gene is mediated by ERE half sites without direct binding of estrogen receptor.

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Bahadur, Urvashi; Ganjam, Goutham K; Vasudevan, Nandini; Kondaiah, Paturu

2005-02-28

Estrogen is an important steroid hormone that mediates most of its effects on regulation of gene expression by binding to intracellular receptors. The consensus estrogen response element (ERE) is a 13bp palindromic inverted repeat with a three nucleotide spacer. However, several reports suggest that many estrogen target genes are regulated by diverse elements, such as imperfect EREs and ERE half sites (ERE 1/2), which are either the proximal or the distal half of the palindrome. To gain more insight into ERE half site-mediated gene regulation, we used a region from the estrogen-regulated chicken riboflavin carrier protein (RCP) gene promoter that contains ERE half sites. Using moxestrol, an analogue of estrogen and transient transfection of deletion and mutation containing RCP promoter/reporter constructs in chicken hepatoma (LMH2A) cells, we identified an estrogen response unit (ERU) composed of two consensus ERE 1/2 sites and one non-consensus ERE 1/2 site. Mutation of any of these sites within this ERU abolishes moxestrol response. Further, the ERU is able to confer moxestrol responsiveness to a heterologous promoter. Interestingly, RCP promoter is regulated by moxestrol in estrogen responsive human MCF-7 cells, but not in other cell lines such as NIH3T3 and HepG2 despite estrogen receptor-alpha (ER-alpha) co transfection. Electrophoretic mobility shift assays (EMSAs) with promoter regions encompassing the half sites and nuclear extracts from LMH2A cells show the presence of a moxestrol-induced complex that is abolished by a polyclonal anti-ERalpha antibody. Surprisingly, estrogen receptor cannot bind to these promoter elements in isolation. Thus, there appears to be a definite requirement for some other factor(s) in addition to estrogen receptor, for the generation of a suitable response of this promoter to estrogen. Our studies therefore suggest a novel mechanism of gene regulation by estrogen, involving ERE half sites without direct binding of ER to the

A BAYESIAN NONPARAMETRIC MIXTURE MODEL FOR SELECTING GENES AND GENE SUBNETWORKS.

Science.gov (United States)

Zhao, Yize; Kang, Jian; Yu, Tianwei

2014-06-01

It is very challenging to select informative features from tens of thousands of measured features in high-throughput data analysis. Recently, several parametric/regression models have been developed utilizing the gene network information to select genes or pathways strongly associated with a clinical/biological outcome. Alternatively, in this paper, we propose a nonparametric Bayesian model for gene selection incorporating network information. In addition to identifying genes that have a strong association with a clinical outcome, our model can select genes with particular expressional behavior, in which case the regression models are not directly applicable. We show that our proposed model is equivalent to an infinity mixture model for which we develop a posterior computation algorithm based on Markov chain Monte Carlo (MCMC) methods. We also propose two fast computing algorithms that approximate the posterior simulation with good accuracy but relatively low computational cost. We illustrate our methods on simulation studies and the analysis of Spellman yeast cell cycle microarray data.

Directed mutagenesis in Candida albicans: one-step gene disruption to isolate ura3 mutants

International Nuclear Information System (INIS)

Kelly, R.; Miller, S.M.; Kurtz, M.B.; Kirsch, D.R.

1987-01-01

A method for introducing specific mutations into the diploid Candida albicans by one-step gene disruption and subsequent UV-induced recombination was developed. The cloned C. albicans URA3 gene was disrupted with the C. albicans ADE2 gene, and the linearized DNA was used for transformation of two ade2 mutants, SGY-129 and A81-Pu. Both an insertional inactivation of the URA3 gene and a disruption which results in a 4.0-kilobase deletion were made. Southern hybridization analyses demonstrated that the URA3 gene was disrupted on one of the chromosomal homologs in 15 of the 18 transformants analyzed. These analyses also revealed restriction site dimorphism of EcoRI at the URA3 locus which provides a unique marker to distinguish between chromosomal homologs. This enabled us to show that either homolog could be disrupted and that disrupted transformants of SGY-129 contained more than two copies of the URA3 locus. The A81-Pu transformants heterozygous for the ura3 mutations were rendered homozygous and Ura- by UV-induced recombination. The homozygosity of a deletion mutant and an insertion mutant was confirmed by Southern hybridization. Both mutants were transformed to Ura+ with plasmids containing the URA3 gene and in addition, were resistant to 5-fluoro-orotic acid, a characteristic of Saccharomyces cerevisiae ura3 mutants as well as of orotidine-5'-phosphate decarboxylase mutants of other organisms

Inferring Gene Regulatory Networks Using Conditional Regulation Pattern to Guide Candidate Genes.

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Fei Xiao

Full Text Available Combining path consistency (PC algorithms with conditional mutual information (CMI are widely used in reconstruction of gene regulatory networks. CMI has many advantages over Pearson correlation coefficient in measuring non-linear dependence to infer gene regulatory networks. It can also discriminate the direct regulations from indirect ones. However, it is still a challenge to select the conditional genes in an optimal way, which affects the performance and computation complexity of the PC algorithm. In this study, we develop a novel conditional mutual information-based algorithm, namely RPNI (Regulation Pattern based Network Inference, to infer gene regulatory networks. For conditional gene selection, we define the co-regulation pattern, indirect-regulation pattern and mixture-regulation pattern as three candidate patterns to guide the selection of candidate genes. To demonstrate the potential of our algorithm, we apply it to gene expression data from DREAM challenge. Experimental results show that RPNI outperforms existing conditional mutual information-based methods in both accuracy and time complexity for different sizes of gene samples. Furthermore, the robustness of our algorithm is demonstrated by noisy interference analysis using different types of noise.

Genomic Analysis Reveals Contrasting PIFq Contribution to Diurnal Rhythmic Gene Expression in PIF-Induced and -Repressed Genes.

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Martin, Guiomar; Soy, Judit; Monte, Elena

2016-01-01

Members of the PIF quartet (PIFq; PIF1, PIF3, PIF4, and PIF5) collectively contribute to induce growth in Arabidopsis seedlings under short day (SD) conditions, specifically promoting elongation at dawn. Their action involves the direct regulation of growth-related and hormone-associated genes. However, a comprehensive definition of the PIFq-regulated transcriptome under SD is still lacking. We have recently shown that SD and free-running (LL) conditions correspond to "growth" and "no growth" conditions, respectively, correlating with greater abundance of PIF protein in SD. Here, we present a genomic analysis whereby we first define SD-regulated genes at dawn compared to LL in the wild type, followed by identification of those SD-regulated genes whose expression depends on the presence of PIFq. By using this sequential strategy, we have identified 349 PIF/SD-regulated genes, approximately 55% induced and 42% repressed by both SD and PIFq. Comparison with available databases indicates that PIF/SD-induced and PIF/SD-repressed sets are differently phased at dawn and mid-morning, respectively. In addition, we found that whereas rhythmicity of the PIF/SD-induced gene set is lost in LL, most PIF/SD-repressed genes keep their rhythmicity in LL, suggesting differential regulation of both gene sets by the circadian clock. Moreover, we also uncovered distinct overrepresented functions in the induced and repressed gene sets, in accord with previous studies in other examined PIF-regulated processes. Interestingly, promoter analyses showed that, whereas PIF/SD-induced genes are enriched in direct PIF targets, PIF/SD-repressed genes are mostly indirectly regulated by the PIFs and might be more enriched in ABA-regulated genes.

The evolution of milk casein genes from tooth genes before the origin of mammals.

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Kawasaki, Kazuhiko; Lafont, Anne-Gaelle; Sire, Jean-Yves

2011-07-01

Caseins are among cardinal proteins that evolved in the lineage leading to mammals. In milk, caseins and calcium phosphate (CaP) form a huge complex called casein micelle. By forming the micelle, milk maintains high CaP concentrations, which help altricial mammalian neonates to grow bone and teeth. Two types of caseins are known. Ca-sensitive caseins (α(s)- and β-caseins) bind Ca but precipitate at high Ca concentrations, whereas Ca-insensitive casein (κ-casein) does not usually interact with Ca but instead stabilizes the micelle. Thus, it is thought that these two types of caseins are both necessary for stable micelle formation. Both types of caseins show high substitution rates, which make it difficult to elucidate the evolution of caseins. Yet, recent studies have revealed that all casein genes belong to the secretory calcium-binding phosphoprotein (SCPP) gene family that arose by gene duplication. In the present study, we investigated exon-intron structures and phylogenetic distributions of casein and other SCPP genes, particularly the odontogenic ameloblast-associated (ODAM) gene, the SCPP-Pro-Gln-rich 1 (SCPPPQ1) gene, and the follicular dendritic cell secreted peptide (FDCSP) gene. The results suggest that contemporary Ca-sensitive casein genes arose from a putative common ancestor, which we refer to as CSN1/2. The six putative exons comprising CSN1/2 are all found in SCPPPQ1, although ODAM also shares four of these exons. By contrast, the five exons of the Ca-insensitive casein gene are all reminiscent of FDCSP. The phylogenetic distribution of these genes suggests that both SCPPPQ1 and FDCSP arose from ODAM. We thus argue that all casein genes evolved from ODAM via two different pathways; Ca-sensitive casein genes likely originated directly from SCPPPQ1, whereas the Ca-insensitive casein genes directly differentiated from FDCSP. Further, expression of ODAM, SCPPPQ1, and FDCSP was detected in dental tissues, supporting the idea that both types of caseins

Learning gene networks under SNP perturbations using eQTL datasets.

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Lingxue Zhang

2014-02-01

Full Text Available The standard approach for identifying gene networks is based on experimental perturbations of gene regulatory systems such as gene knock-out experiments, followed by a genome-wide profiling of differential gene expressions. However, this approach is significantly limited in that it is not possible to perturb more than one or two genes simultaneously to discover complex gene interactions or to distinguish between direct and indirect downstream regulations of the differentially-expressed genes. As an alternative, genetical genomics study has been proposed to treat naturally-occurring genetic variants as potential perturbants of gene regulatory system and to recover gene networks via analysis of population gene-expression and genotype data. Despite many advantages of genetical genomics data analysis, the computational challenge that the effects of multifactorial genetic perturbations should be decoded simultaneously from data has prevented a widespread application of genetical genomics analysis. In this article, we propose a statistical framework for learning gene networks that overcomes the limitations of experimental perturbation methods and addresses the challenges of genetical genomics analysis. We introduce a new statistical model, called a sparse conditional Gaussian graphical model, and describe an efficient learning algorithm that simultaneously decodes the perturbations of gene regulatory system by a large number of SNPs to identify a gene network along with expression quantitative trait loci (eQTLs that perturb this network. While our statistical model captures direct genetic perturbations of gene network, by performing inference on the probabilistic graphical model, we obtain detailed characterizations of how the direct SNP perturbation effects propagate through the gene network to perturb other genes indirectly. We demonstrate our statistical method using HapMap-simulated and yeast eQTL datasets. In particular, the yeast gene network

Transduction of Oct6 or Oct9 gene concomitant with Myc family gene induced osteoblast-like phenotypic conversion in normal human fibroblasts.

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Mizoshiri, N; Kishida, T; Yamamoto, K; Shirai, T; Terauchi, R; Tsuchida, S; Mori, Y; Ejima, A; Sato, Y; Arai, Y; Fujiwara, H; Yamamoto, T; Kanamura, N; Mazda, O; Kubo, T

2015-11-27

Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. We examined which Oct family genes and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Artificial neural network inference (ANNI: a study on gene-gene interaction for biomarkers in childhood sarcomas.

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Dong Ling Tong

Full Text Available OBJECTIVE: To model the potential interaction between previously identified biomarkers in children sarcomas using artificial neural network inference (ANNI. METHOD: To concisely demonstrate the biological interactions between correlated genes in an interaction network map, only 2 types of sarcomas in the children small round blue cell tumors (SRBCTs dataset are discussed in this paper. A backpropagation neural network was used to model the potential interaction between genes. The prediction weights and signal directions were used to model the strengths of the interaction signals and the direction of the interaction link between genes. The ANN model was validated using Monte Carlo cross-validation to minimize the risk of over-fitting and to optimize generalization ability of the model. RESULTS: Strong connection links on certain genes (TNNT1 and FNDC5 in rhabdomyosarcoma (RMS; FCGRT and OLFM1 in Ewing's sarcoma (EWS suggested their potency as central hubs in the interconnection of genes with different functionalities. The results showed that the RMS patients in this dataset are likely to be congenital and at low risk of cardiomyopathy development. The EWS patients are likely to be complicated by EWS-FLI fusion and deficiency in various signaling pathways, including Wnt, Fas/Rho and intracellular oxygen. CONCLUSIONS: The ANN network inference approach and the examination of identified genes in the published literature within the context of the disease highlights the substantial influence of certain genes in sarcomas.

Gene mining a marama bean expressed sequence tags (ESTs ...

African Journals Online (AJOL)

The authors reported the identification of genes associated with embryonic development and microsatellite sequences. The future direction will entail characterization of these genes using gene over-expression and mutant assays. Key words: Namibia, simple sequence repeats (SSR), data mining, homology searches, ...

ChIP-on-chip analysis identifies IL-22 as direct target gene of ectopically expressed FOXP3 transcription factor in human T cells

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Jeron Andreas

2012-12-01

Full Text Available Abstract Background The transcription factor (TF forkhead box P3 (FOXP3 is constitutively expressed at high levels in naturally occurring CD4+CD25+ regulatory T cells (nTregs. It is not only the most accepted marker for that cell population but is also considered lineage determinative. Chromatin immunoprecipitation (ChIP of TFs in combination with genomic tiling microarray analysis (ChIP-on-chip has been shown to be an appropriate tool for identifying FOXP3 transcription factor binding sites (TFBSs on a genome-wide scale. In combination with microarray expression analysis, the ChIP-on-chip technique allows identification of direct FOXP3 target genes. Results ChIP-on-chip analysis of the human FOXP3 expressed in resting and PMA/ionomycin–stimulated Jurkat T cells revealed several thousand putative FOXP3 binding sites and demonstrated the importance of intronic regions for FOXP3 binding. The analysis of expression data showed that the stimulation-dependent down-regulation of IL-22 was correlated with direct FOXP3 binding in the IL-22 promoter region. This association was confirmed by real-time PCR analysis of ChIP-DNA. The corresponding ChIP-region also contained a matching FOXP3 consensus sequence. Conclusions Knowledge of the general distribution patterns of FOXP3 TFBSs in the human genome under resting and activated conditions will contribute to a better understanding of this TF and its influence on direct target genes, as well as its importance for the phenotype and function of Tregs. Moreover, FOXP3-dependent repression of Th17-related IL-22 may be relevant to an understanding of the phenomenon of Treg/Th17 cell plasticity.

The bystander effect of cancer gene therapy

International Nuclear Information System (INIS)

Lumniczky, K.; Safrany, G.

2008-01-01

Cancer gene therapy is a new, promising therapeutic agent. In the clinic, it should be used in combination with existing modalities, such as tumour irradiation. First, we summarise the most important fields of cancer gene therapy: gene directed enzyme pro-drug therapy; the activation of an anti-tumour immune attack; restoration of the wild type p53 status; the application of new, replication competent and oncolytic viral vectors; tumour specific, as well as radiation- and hypoxia-induced gene expression. Special emphasizes are put on the combined effect of these modalities with local tumour irradiation. Using the available vector systems, only a small portion of the cancer cells will contain the therapeutic genes under therapeutic situations. Bystander cell killing might contribute to the success of various gene therapy protocols. We summarise the evidences that lethal bystander effects may occur during cancer gene therapy. Bystander effects are especially important in the gene directed enzyme pro-drug therapy. There, bystander cell killing might have different routes: cell communication through gap junction intercellular contacts; release of toxic metabolites into the neighbourhood or to larger distances; phagocytosis of apoptotic bodies; and the activation of the immune system. Bystander cell killing can be enhanced by the introduction of gap junction proteins into the cells, by further activating the immune system with immune-stimulatory molecules, or by introducing genes into the cells that help the transfer of cytotoxic genes and / or metabolites into the bystander cells. In conclusion, there should be additional improvements in cancer gene therapy for the more efficient clinical application. (orig.)

Identification of a cis-regulatory element by transient analysis of co-ordinately regulated genes

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Allan Andrew C

2008-07-01

Full Text Available Abstract Background Transcription factors (TFs co-ordinately regulate target genes that are dispersed throughout the genome. This co-ordinate regulation is achieved, in part, through the interaction of transcription factors with conserved cis-regulatory motifs that are in close proximity to the target genes. While much is known about the families of transcription factors that regulate gene expression in plants, there are few well characterised cis-regulatory motifs. In Arabidopsis, over-expression of the MYB transcription factor PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT 1 leads to transgenic plants with elevated anthocyanin levels due to the co-ordinated up-regulation of genes in the anthocyanin biosynthetic pathway. In addition to the anthocyanin biosynthetic genes, there are a number of un-associated genes that also change in expression level. This may be a direct or indirect consequence of the over-expression of PAP1. Results Oligo array analysis of PAP1 over-expression Arabidopsis plants identified genes co-ordinately up-regulated in response to the elevated expression of this transcription factor. Transient assays on the promoter regions of 33 of these up-regulated genes identified eight promoter fragments that were transactivated by PAP1. Bioinformatic analysis on these promoters revealed a common cis-regulatory motif that we showed is required for PAP1 dependent transactivation. Conclusion Co-ordinated gene regulation by individual transcription factors is a complex collection of both direct and indirect effects. Transient transactivation assays provide a rapid method to identify direct target genes from indirect target genes. Bioinformatic analysis of the promoters of these direct target genes is able to locate motifs that are common to this sub-set of promoters, which is impossible to identify with the larger set of direct and indirect target genes. While this type of analysis does not prove a direct interaction between protein and DNA

Regulation of T cell activation by HIV-1 accessory proteins: Vpr acts via distinct mechanisms to cooperate with Nef in NFAT-directed gene expression and to promote transactivation by CREB

International Nuclear Information System (INIS)

Lahti, Anna L.; Manninen, Aki; Saksela, Kalle

2003-01-01

Nef and Vpr are lentiviral accessory proteins that have been implicated in regulation of cellular gene expression. We noticed that Vpr can potentiate Nef-induced activation of nuclear factor of activated T cells (NFAT)-dependent transcription. Unlike Nef, which stimulated calcium signaling to activate NFAT, Vpr functioned farther downstream. Similar to the positive effects of Vpr on most of the transcriptional test systems that we used, potentiation of NFAT-directed gene expression was relatively modest in magnitude (two- to threefold) and depended on the cell cycle-arresting capacity of Vpr. By contrast, we found that Vpr could cause more than fivefold upregulation of cyclic AMP response element (CRE)-directed transcription via a mechanism that did not require Vpr-induced G2/M arrest. This effect, however, was only evident under suboptimal conditions known to lead to serine phosphorylation of the CRE binding factor (CREB) but not to CREB-dependent gene expression. This suggested that Vpr may act by stabilizing interactions with CREB and its transcriptional cofactor CREB binding protein (CBP). Indeed, this effect could be blocked by cotransfection of the adenoviral CBP inhibitor E1A. These results provide additional evidence for cell cycle-independent regulation of gene expression by Vpr and implicate CREB as a potentially important target for Vpr action in HIV-infected host cells

Gene × Smoking Interactions on Human Brain Gene Expression: Finding Common Mechanisms in Adolescents and Adults

Science.gov (United States)

Wolock, Samuel L.; Yates, Andrew; Petrill, Stephen A.; Bohland, Jason W.; Blair, Clancy; Li, Ning; Machiraju, Raghu; Huang, Kun; Bartlett, Christopher W.

2013-01-01

Background: Numerous studies have examined gene × environment interactions (G × E) in cognitive and behavioral domains. However, these studies have been limited in that they have not been able to directly assess differential patterns of gene expression in the human brain. Here, we assessed G × E interactions using two publically available datasets…

Using the gene ontology to scan multilevel gene sets for associations in genome wide association studies.

Science.gov (United States)

Schaid, Daniel J; Sinnwell, Jason P; Jenkins, Gregory D; McDonnell, Shannon K; Ingle, James N; Kubo, Michiaki; Goss, Paul E; Costantino, Joseph P; Wickerham, D Lawrence; Weinshilboum, Richard M

2012-01-01

Gene-set analyses have been widely used in gene expression studies, and some of the developed methods have been extended to genome wide association studies (GWAS). Yet, complications due to linkage disequilibrium (LD) among single nucleotide polymorphisms (SNPs), and variable numbers of SNPs per gene and genes per gene-set, have plagued current approaches, often leading to ad hoc "fixes." To overcome some of the current limitations, we developed a general approach to scan GWAS SNP data for both gene-level and gene-set analyses, building on score statistics for generalized linear models, and taking advantage of the directed acyclic graph structure of the gene ontology when creating gene-sets. However, other types of gene-set structures can be used, such as the popular Kyoto Encyclopedia of Genes and Genomes (KEGG). Our approach combines SNPs into genes, and genes into gene-sets, but assures that positive and negative effects of genes on a trait do not cancel. To control for multiple testing of many gene-sets, we use an efficient computational strategy that accounts for LD and provides accurate step-down adjusted P-values for each gene-set. Application of our methods to two different GWAS provide guidance on the potential strengths and weaknesses of our proposed gene-set analyses. © 2011 Wiley Periodicals, Inc.

Evaluating the consistency of gene sets used in the analysis of bacterial gene expression data

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Tintle Nathan L

2012-08-01

Full Text Available Abstract Background Statistical analyses of whole genome expression data require functional information about genes in order to yield meaningful biological conclusions. The Gene Ontology (GO and Kyoto Encyclopedia of Genes and Genomes (KEGG are common sources of functionally grouped gene sets. For bacteria, the SEED and MicrobesOnline provide alternative, complementary sources of gene sets. To date, no comprehensive evaluation of the data obtained from these resources has been performed. Results We define a series of gene set consistency metrics directly related to the most common classes of statistical analyses for gene expression data, and then perform a comprehensive analysis of 3581 Affymetrix® gene expression arrays across 17 diverse bacteria. We find that gene sets obtained from GO and KEGG demonstrate lower consistency than those obtained from the SEED and MicrobesOnline, regardless of gene set size. Conclusions Despite the widespread use of GO and KEGG gene sets in bacterial gene expression data analysis, the SEED and MicrobesOnline provide more consistent sets for a wide variety of statistical analyses. Increased use of the SEED and MicrobesOnline gene sets in the analysis of bacterial gene expression data may improve statistical power and utility of expression data.

Deconstructing the pluripotency gene regulatory network

KAUST Repository

Li, Mo

2018-04-04

Pluripotent stem cells can be isolated from embryos or derived by reprogramming. Pluripotency is stabilized by an interconnected network of pluripotency genes that cooperatively regulate gene expression. Here we describe the molecular principles of pluripotency gene function and highlight post-transcriptional controls, particularly those induced by RNA-binding proteins and alternative splicing, as an important regulatory layer of pluripotency. We also discuss heterogeneity in pluripotency regulation, alternative pluripotency states and future directions of pluripotent stem cell research.

Deconstructing the pluripotency gene regulatory network

KAUST Repository

Li, Mo; Belmonte, Juan Carlos Izpisua

2018-01-01

Pluripotent stem cells can be isolated from embryos or derived by reprogramming. Pluripotency is stabilized by an interconnected network of pluripotency genes that cooperatively regulate gene expression. Here we describe the molecular principles of pluripotency gene function and highlight post-transcriptional controls, particularly those induced by RNA-binding proteins and alternative splicing, as an important regulatory layer of pluripotency. We also discuss heterogeneity in pluripotency regulation, alternative pluripotency states and future directions of pluripotent stem cell research.

Org-1, the Drosophila ortholog of Tbx1, is a direct activator of known identity genes during muscle specification.

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Schaub, Christoph; Nagaso, Hideyuki; Jin, Hong; Frasch, Manfred

2012-03-01

Members of the T-Box gene family of transcription factors are important players in regulatory circuits that generate myogenic and cardiogenic lineage diversities in vertebrates. We show that during somatic myogenesis in Drosophila, the single ortholog of vertebrate Tbx1, optomotor-blind-related-gene-1 (org-1), is expressed in a small subset of muscle progenitors, founder cells and adult muscle precursors, where it overlaps with the products of the muscle identity genes ladybird (lb) and slouch (slou). In addition, org-1 is expressed in the lineage of the heart-associated alary muscles. org-1 null mutant embryos lack Lb and Slou expression within the muscle lineages that normally co-express org-1. As a consequence, the respective muscle fibers and adult muscle precursors are either severely malformed or missing, as are the alary muscles. To address the mechanisms that mediate these regulatory interactions between Org-1, Lb and Slou, we characterized distinct enhancers associated with somatic muscle expression of lb and slou. We demonstrate that these lineage- and stage-specific cis-regulatory modules (CRMs) bind Org-1 in vivo, respond to org-1 genetically and require T-box domain binding sites for their activation. In summary, we propose that org-1 is a common and direct upstream regulator of slou and lb in the developmental pathway of these two neighboring muscle lineages. Cross-repression between slou and lb and combinatorial activation of lineage-specific targets by Org-1-Slou and Org-1-Lb, respectively, then leads to the distinction between the two lineages. These findings provide new insights into the regulatory circuits that control the proper pattering of the larval somatic musculature in Drosophila.

Improved animal models for testing gene therapy for atherosclerosis.

Science.gov (United States)

Du, Liang; Zhang, Jingwan; De Meyer, Guido R Y; Flynn, Rowan; Dichek, David A

2014-04-01

Gene therapy delivered to the blood vessel wall could augment current therapies for atherosclerosis, including systemic drug therapy and stenting. However, identification of clinically useful vectors and effective therapeutic transgenes remains at the preclinical stage. Identification of effective vectors and transgenes would be accelerated by availability of animal models that allow practical and expeditious testing of vessel-wall-directed gene therapy. Such models would include humanlike lesions that develop rapidly in vessels that are amenable to efficient gene delivery. Moreover, because human atherosclerosis develops in normal vessels, gene therapy that prevents atherosclerosis is most logically tested in relatively normal arteries. Similarly, gene therapy that causes atherosclerosis regression requires gene delivery to an existing lesion. Here we report development of three new rabbit models for testing vessel-wall-directed gene therapy that either prevents or reverses atherosclerosis. Carotid artery intimal lesions in these new models develop within 2-7 months after initiation of a high-fat diet and are 20-80 times larger than lesions in a model we described previously. Individual models allow generation of lesions that are relatively rich in either macrophages or smooth muscle cells, permitting testing of gene therapy strategies targeted at either cell type. Two of the models include gene delivery to essentially normal arteries and will be useful for identifying strategies that prevent lesion development. The third model generates lesions rapidly in vector-naïve animals and can be used for testing gene therapy that promotes lesion regression. These models are optimized for testing helper-dependent adenovirus (HDAd)-mediated gene therapy; however, they could be easily adapted for testing of other vectors or of different types of molecular therapies, delivered directly to the blood vessel wall. Our data also supports the promise of HDAd to deliver long

Discovering genes underlying QTL

Energy Technology Data Exchange (ETDEWEB)

Vanavichit, Apichart [Kasetsart University, Kamphaengsaen, Nakorn Pathom (Thailand)

2002-02-01

A map-based approach has allowed scientists to discover few genes at a time. In addition, the reproductive barrier between cultivated rice and wild relatives has prevented us from utilizing the germ plasm by a map-based approach. Most genetic traits important to agriculture or human diseases are manifested as observable, quantitative phenotypes called Quantitative Trait Loci (QTL). In many instances, the complexity of the phenotype/genotype interaction and the general lack of clearly identifiable gene products render the direct molecular cloning approach ineffective, thus additional strategies like genome mapping are required to identify the QTL in question. Genome mapping requires no prior knowledge of the gene function, but utilizes statistical methods to identify the most likely gene location. To completely characterize genes of interest, the initially mapped region of a gene location will have to be narrowed down to a size that is suitable for cloning and sequencing. Strategies for gene identification within the critical region have to be applied after the sequencing of a potentially large clone or set of clones that contains this gene(s). Tremendous success of positional cloning has been shown for cloning many genes responsible for human diseases, including cystic fibrosis and muscular dystrophy as well as plant disease resistance genes. Genome and QTL mapping, positional cloning: the pre-genomics era, comparative approaches to gene identification, and positional cloning: the genomics era are discussed in the report. (M. Suetake)

hebp3, a novel member of the heme-binding protein gene family, is expressed in the medaka meninges with higher abundance in females due to a direct stimulating action of ovarian estrogens.

Science.gov (United States)

Nakasone, Kiyoshi; Nagahama, Yoshitaka; Okubo, Kataaki

2013-02-01

The brains of teleost fish exhibit remarkable sexual plasticity throughout their life span. To dissect the molecular basis for the development and reversal of sex differences in the teleost brain, we screened for genes differentially expressed between sexes in the brain of medaka (Oryzias latipes). One of the genes identified in the screen as being preferentially expressed in females was found to be a new member of the heme-binding protein gene family that includes hebp1 and hebp2 and was designated here as hebp3. The medaka hebp3 is expressed in the meninges with higher abundance in females, whereas there is no expression within the brain parenchyma. This female-biased expression of hebp3 is not attributable to the direct action of sex chromosome genes but results from the transient and reversible action of estrogens derived from the ovary. Moreover, estrogens directly activate the transcription of hebp3 via a palindromic estrogen-responsive element in the hebp3 promoter. Taken together, our findings demonstrate that hebp3 is a novel transcriptional target of estrogens, with female-biased expression in the meninges. The definite but reversible sexual dimorphism of the meningeal hebp3 expression may contribute to the development and reversal of sex differences in the teleost brain.

Estimating directional epistasis

Science.gov (United States)

Le Rouzic, Arnaud

2014-01-01

Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

Adenoviral delivery of pan-caspase inhibitor p35 enhances bystander killing by P450 gene-directed enzyme prodrug therapy using cyclophosphamide+

International Nuclear Information System (INIS)

Doloff, Joshua C; Su, Ting; Waxman, David J

2010-01-01

Cytochrome P450-based suicide gene therapy for cancer using prodrugs such as cyclophosphamide (CPA) increases anti-tumor activity, both directly and via a bystander killing mechanism. Bystander cell killing is essential for the clinical success of this treatment strategy, given the difficulty of achieving 100% efficient gene delivery in vivo using current technologies. Previous studies have shown that the pan-caspase inhibitor p35 significantly increases CPA-induced bystander killing by tumor cells that stably express P450 enzyme CYP2B6 (Schwartz et al, (2002) Cancer Res. 62: 6928-37). To further develop this approach, we constructed and characterized a replication-defective adenovirus, Adeno-2B6/p35, which expresses p35 in combination with CYP2B6 and its electron transfer partner, P450 reductase. The expression of p35 in Adeno-2B6/p35-infected tumor cells inhibited caspase activation, delaying the death of the CYP2B6 'factory' cells that produce active CPA metabolites, and increased bystander tumor cell killing compared to that achieved in the absence of p35. Tumor cells infected with Adeno-2B6/p35 were readily killed by cisplatin and doxorubicin, indicating that p35 expression is not associated with acquisition of general drug resistance. Finally, p35 did not inhibit viral release when the replication-competent adenovirus ONYX-017 was used as a helper virus to facilitate co-replication and spread of Adeno-2B6/p35 and further increase CPA-induced bystander cell killing. The introduction of p35 into gene therapeutic regimens constitutes an effective approach to increase bystander killing by cytochrome P450 gene therapy. This strategy may also be used to enhance other bystander cytotoxic therapies, including those involving the production of tumor cell toxic protein products

Tracking microorganisms and gene in the environment

International Nuclear Information System (INIS)

Atlas, R.M.; Sayler, G.S.

1988-01-01

Studies have been conducted to determine the sensitivities and limitations of various methods for determining the fate of genetically engineered microorganisms (GEMs) and their genes in the environment. Selective viable plate count procedures can be designed to detect the introduced organisms with high sensitivity; but they are restricted by potential mutations affecting the expression of the selective characteristic in the introduced organism, the occurrence of the particular selective characteristic in the indigenous organisms, and the need to culture the organism. The accuracy of this approach is greatly improved by colony hybridization procedures that use a specific gene probe to detect the introduced genes, but this approach is still only as sensitive as the plating procedure. Direct extraction of DNA from environmental samples, coupled with dot blot hybridization with radiolabeled probe DNA or solution hybridization, gives a high degree of both sensitivity and precision. This approach does not require culturing of the organism; and even if an introduced gene moves into a new organism or if the introduced organism is viable but nonculturable, the gene probe methods will detect the persistence of the introduced genes in the environment. Efficient direct DNA extraction methods have been developed and tested following in vitro experimental additions of GEMs to sediment and water samples

AAV Vectorization of DSB-mediated Gene Editing Technologies.

Science.gov (United States)

Moser, Rachel J; Hirsch, Matthew L

2016-01-01

Recent work both at the bench and the bedside demonstrate zinc-finger nucleases (ZFNs), CRISPR/Cas9, and other programmable site-specific endonuclease technologies are being successfully utilized within and alongside AAV vectors to induce therapeutically relevant levels of directed gene editing within the human chromosome. Studies from past decades acknowledge that AAV vector genomes are enhanced substrates for homology-directed repair in the presence or absence of targeted DNA damage within the host genome. Additionally, AAV vectors are currently the most efficient format for in vivo gene delivery with no vector related complications in >100 clinical trials for diverse diseases. At the same time, advancements in the design of custom-engineered site-specific endonucleases and the utilization of elucidated endonuclease formats have resulted in efficient and facile genetic engineering for basic science and for clinical therapies. AAV vectors and gene editing technologies are an obvious marriage, using AAV for the delivery of repair substrate and/or a gene encoding a designer endonuclease; however, while efficient delivery and enhanced gene targeting by vector genomes are advantageous, other attributes of AAV vectors are less desirable for gene editing technologies. This review summarizes the various roles that AAV vectors play in gene editing technologies and provides insight into its trending applications for the treatment of genetic diseases.

The human oxytocin gene promoter is regulated by estrogens.

Science.gov (United States)

Richard, S; Zingg, H H

1990-04-15

Gonadal steroids affect brain function primarily by altering the expression of specific genes, yet the specific mechanisms by which neuronal target genes undergo such regulation are unknown. Recent evidence suggests that the expression of the neuropeptide gene for oxytocin (OT) is modulated by estrogens. We therefore examined the possibility that this regulation occurred via a direct interaction of the estrogen-receptor complex with cis-acting elements flanking the OT gene. DNA-mediated gene transfer experiments were performed using Neuro-2a neuroblastoma cells and chimeric plasmids containing portions of the human OT gene 5'-glanking region linked to the chloramphenicol acetyltransferase gene. We identified a 19-base pair region located at -164 to -146 upstream of the transcription start site which is capable of conferring estrogen responsiveness to the homologous as well as to a heterologous promoter. The hormonal response is strictly dependent on the presence of intracellular estrogen receptors, since estrogen induced stimulation occurred only in Neuro-2a cells co-transfected with an expression vector for the human estrogen receptor. The identified region contains a novel imperfect palindrome (GGTGACCTTGACC) with sequence similarity to other estrogen response elements (EREs). To define cis-acting elements that function in synergism with the ERE, sequences 3' to the ERE were deleted, including the CCAAT box, two additional motifs corresponding to the right half of the ERE palindrome (TGACC), as well as a CTGCTAA heptamer similar to the "elegans box" found in Caenorhabditis elegans. Interestingly, optimal function of the identified ERE was fully independent of these elements and only required a short promoter region (-49 to +36). Our studies define a molecular mechanism by which estrogens can directly modulate OT gene expression. However, only a subset of OT neurons are capable of binding estrogens, therefore, direct action of estrogens on the OT gene may be

Lack of direct evidence for natural selection at the candidate thrifty gene locus, PPARGC1A.

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Cadzow, Murray; Merriman, Tony R; Boocock, James; Dalbeth, Nicola; Stamp, Lisa K; Black, Michael A; Visscher, Peter M; Wilcox, Phillip L

2016-11-15

The gene PPARGC1A, in particular the Gly482Ser variant (rs8192678), had been proposed to be subject to natural selection, particularly in recent progenitors of extant Polynesian populations. Reasons include high levels of population differentiation and increased frequencies of the derived type 2 diabetes (T2D) risk 482Ser allele, and association with body mass index (BMI) in a small Tongan population. However, no direct statistical tests for selection have been applied. Using a range of Polynesian populations (Tongan, Māori, Samoan) we re-examined evidence for association between Gly482Ser with T2D and BMI as well as gout. Using also Asian, European, and African 1000 Genome Project samples a range of statistical tests for selection (F ST , integrated haplotype score (iHS), cross population extended haplotype homozygosity (XP-EHH), Tajima's D and Fay and Wu's H) were conducted on the PPARGC1A locus. No statistically significant evidence for association between Gly482Ser and any of BMI, T2D or gout was found. Population differentiation (F ST ) was smallest between Asian and Pacific populations (New Zealand Māori ≤ 0.35, Samoan ≤ 0.20). When compared to European (New Zealand Māori ≤ 0.40, Samoan ≤ 0.25) or African populations (New Zealand Māori ≤ 0.80, Samoan ≤ 0.66) this differentiation was larger. We did not find any strong evidence for departure from neutral evolution at this locus when applying any of the other statistical tests for selection. However, using the same analytical methods, we found evidence for selection in specific populations at previously identified loci, indicating that lack of selection was the most likely explanation for the lack of evidence of selection in PPARGC1A. We conclude that there is no compelling evidence for selection at this locus, and that this gene should not be considered a candidate thrifty gene locus in Pacific populations. High levels of population differentiation at this locus and the

Recent Trends of Polymer Mediated Liposomal Gene Delivery System

Directory of Open Access Journals (Sweden)

Shyamal Kumar Kundu

2014-01-01

Full Text Available Advancement in the gene delivery system have resulted in clinical successes in gene therapy for patients with several genetic diseases, such as immunodeficiency diseases, X-linked adrenoleukodystrophy (X-ALD blindness, thalassemia, and many more. Among various delivery systems, liposomal mediated gene delivery route is offering great promises for gene therapy. This review is an attempt to depict a portrait about the polymer based liposomal gene delivery systems and their future applications. Herein, we have discussed in detail the characteristics of liposome, importance of polymer for liposome formulation, gene delivery, and future direction of liposome based gene delivery as a whole.

Transduction of Oct6 or Oct9 gene concomitant with Myc family gene induced osteoblast-like phenotypic conversion in normal human fibroblasts

International Nuclear Information System (INIS)

Mizoshiri, N.; Kishida, T.; Yamamoto, K.; Shirai, T.; Terauchi, R.; Tsuchida, S.; Mori, Y.; Ejima, A.; Sato, Y.; Arai, Y.; Fujiwara, H.; Yamamoto, T.; Kanamura, N.; Mazda, O.; Kubo, T.

2015-01-01

Introduction: Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. Materials and Methods: We examined which Oct family genes and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. Results: As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. Discussion: The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases. - Highlights: • Introducing L-myc in a combination with either Oct3/4, Oct6 or Oct9 enables the conversion of fibroblasts to osteoblasts. • A combination of L-myc with Oct3/4 or Oct9 can induce the cells to a phenotype closer to normal osteoblasts. • N-myc was considered the most appropriate Myc family gene for induction of osteoblast-like phenotype in fibroblasts. • The combination of Oct9 plus N-myc has the strongest capability of inducing osteoblast-like phenotype.

Transduction of Oct6 or Oct9 gene concomitant with Myc family gene induced osteoblast-like phenotypic conversion in normal human fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Mizoshiri, N. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto (Japan); Kishida, T. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Yamamoto, K. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Department of Dental Medicine, Kyoto Prefectural University of Medicine, Kyoto (Japan); Shirai, T.; Terauchi, R.; Tsuchida, S. [Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto (Japan); Mori, Y. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto (Japan); Ejima, A. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Sato, Y. [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Department of Dental Medicine, Kyoto Prefectural University of Medicine, Kyoto (Japan); Arai, Y.; Fujiwara, H. [Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto (Japan); Yamamoto, T.; Kanamura, N. [Department of Dental Medicine, Kyoto Prefectural University of Medicine, Kyoto (Japan); Mazda, O., E-mail: mazda@koto.kpu-m.ac.jp [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Kubo, T. [Department of Orthopaedics, Kyoto Prefectural University of Medicine, Kyoto (Japan)

2015-11-27

Introduction: Osteoblasts play essential roles in bone formation and regeneration, while they have low proliferation potential. Recently we established a procedure to directly convert human fibroblasts into osteoblasts (dOBs). Transduction of Runx2 (R), Osterix (X), Oct3/4 (O) and L-myc (L) genes followed by culturing under osteogenic conditions induced normal human fibroblasts to express osteoblast-specific genes and produce calcified bone matrix both in vitro and in vivo Intriguingly, a combination of only two factors, Oct3/4 and L-myc, significantly induced osteoblast-like phenotype in fibroblasts, but the mechanisms underlying the direct conversion remains to be unveiled. Materials and Methods: We examined which Oct family genes and Myc family genes are capable of inducing osteoblast-like phenotypic conversion. Results: As result Oct3/4, Oct6 and Oct9, among other Oct family members, had the capability, while N-myc was the most effective Myc family gene. The Oct9 plus N-myc was the best combination to induce direct conversion of human fibroblasts into osteoblast-like cells. Discussion: The present findings may greatly contribute to the elucidation of the roles of the Oct and Myc proteins in osteoblast direct reprogramming. The results may also lead to establishment of novel regenerative therapy for various bone resorption diseases. - Highlights: • Introducing L-myc in a combination with either Oct3/4, Oct6 or Oct9 enables the conversion of fibroblasts to osteoblasts. • A combination of L-myc with Oct3/4 or Oct9 can induce the cells to a phenotype closer to normal osteoblasts. • N-myc was considered the most appropriate Myc family gene for induction of osteoblast-like phenotype in fibroblasts. • The combination of Oct9 plus N-myc has the strongest capability of inducing osteoblast-like phenotype.

Creation of a cardiotropic adeno-associated virus: the story of viral directed evolution

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Yang Lin

2013-02-01

Full Text Available Abstract Adeno-associated virus (AAV is an important vector system for human gene therapy. Although use of AAV serotypes can result in efficient myocardial gene transfer, improvements in the transduction efficiency and specificity are still required. As a method for artificial modification and selection of gene function, directed evolution has been used for diverse applications in genetic engineering of enzymes and proteins. Since 2000, pioneering work has been performed on directed evolution of viral vectors. We further attempted to evolve the AAV using DNA shuffling and in vivo biopanning in a mouse model. An AAVM41 mutant was characterized, which was found to have improved transduction efficiency and specificity in myocardium, an attribute unknown for any natural AAV serotypes. This review focuses on the development of AAV vector for cardiac gene transfer, the history of directed evolution of viral vectors, and our creation of a cardiotropic AAV, which might have implications for the future design and application of viral vectors.

The direct effect of Focal Adhesion Kinase (FAK, dominant-negative FAK, FAK-CD and FAK siRNA on gene expression and human MCF-7 breast cancer cell tumorigenesis

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Zhang Li

2009-08-01

Full Text Available Abstract Background Focal adhesion kinase (FAK is a non-receptor tyrosine kinase that plays an important role in survival signaling. FAK has been shown to be overexpressed in breast cancer tumors at early stages of tumorigenesis. Methods To study the direct effect of FAK on breast tumorigenesis, we developed Tet-ON (tetracycline-inducible system of MCF-7 breast cancer cells stably transfected with FAK or dominant-negative, C-terminal domain of FAK (FAK-CD, and also FAKsiRNA with silenced FAK MCF-7 stable cell line. Increased expression of FAK in isogenic Tet-inducible MCF-7 cells caused increased cell growth, adhesion and soft agar colony formation in vitro, while expression of dominant-negative FAK inhibitor caused inhibition of these cellular processes. To study the role of induced FAK and FAK-CD in vivo, we inoculated these Tet-inducible cells in nude mice to generate tumors in the presence or absence of doxycycline in the drinking water. FAKsiRNA-MCF-7 cells were also injected into nude mice to generate xenograft tumors. Results Induction of FAK resulted in significant increased tumorigenesis, while induced FAK-CD resulted in decreased tumorigenesis. Taq Man Low Density Array assay demonstrated specific induction of FAKmRNA in MCF-7-Tet-ON-FAK cells. DMP1, encoding cyclin D binding myb-like protein 1 was one of the genes specifically affected by Tet-inducible FAK or FAK-CD in breast xenograft tumors. In addition, silencing of FAK in MCF-7 cells with FAK siRNA caused increased cell rounding, decreased cell viability in vitro and inhibited tumorigenesis in vivo. Importantly, Affymetrix microarray gene profiling analysis using Human Genome U133A GeneChips revealed >4300 genes, known to be involved in apoptosis, cell cycle, and adhesion that were significantly down- or up-regulated (p Conclusion Thus, these data for the first time demonstrate the direct effect of FAK expression and function on MCF-7 breast cancer tumorigenesis in vivo and reveal

Widespread and highly persistent gene transfer to the CNS by retrovirus vector in utero: implication for gene therapy to Krabbe disease.

Science.gov (United States)

Shen, Jin-Song; Meng, Xing-Li; Yokoo, Takashi; Sakurai, Ken; Watabe, Kazuhiko; Ohashi, Toya; Eto, Yoshikatsu

2005-05-01

Brain-directed prenatal gene therapy may benefit some lysosomal storage diseases that affect the central nervous system (CNS) before birth. Our previous study showed that intrauterine introduction of recombinant adenoviruses into cerebral ventricles results in efficient gene transfer to the CNS in the mouse. However, transgene expression decreased with time due to the non-integrative property of adenoviral vectors. In this study, in order to obtain permanent gene transduction, we investigated the feasibility of retrovirus-mediated in utero gene transduction. Concentrated retrovirus encoding the LacZ gene was injected into the cerebral ventricles of the embryos of normal and twitcher mice (a murine model of Krabbe disease) at embryonic day 12. The distribution and maintenance of the transgene expression in the recipient brain were analyzed histochemically, biochemically and by the quantitative polymerase chain reaction method pre- and postnatally. Efficient and highly persistent gene transduction to the brain was achieved both in normal and the twitcher mouse. Transduced neurons, astrocytes and oligodendrocytes were distributed throughout the brain. The transduced LacZ gene, its transcript and protein expression in the brain were maintained for 14 months without decrement. In addition, gene transduction to multiple tissues other than the brain was also detected at low levels. This study suggests that brain-directed in utero gene transfer using retrovirus vector may be beneficial to the treatment of lysosomal storage diseases with severe brain damage early in life, such as Krabbe disease. Copyright (c) 2005 John Wiley & Sons, Ltd.

The Scope of Gene Patent Protection and the TRIPS Agreement

DEFF Research Database (Denmark)

Sommer, Tine

2007-01-01

The Scope of Gene Patent Protection and the TRIPS Agreement - An Exclusively Nondiscriminatory Approach?   Gene patenting in Europe has provoked much debate both before and since the adoption of Directive 98/44/EC on the legal protection of biotechnological inventions. Some of the major points...... of discussion have been focused on the scope of protection (e.g. purpose-bound protection) and gene patents being subject to a specific DNA regime on patent rights. The Directive can be interpreted as favouring such a solution, but so far the European Commission has decided neither to support nor reject...

Decoding Gene Patents in Australia

OpenAIRE

Denley, Adam; Cherry, James

2015-01-01

Patents directed to naturally occurring genetic material, such as DNA, RNA, chromosomes, and genes, in an isolated or purified form have been granted in Australia for many years. This review provides scientists with a summary of the gene patent debate from an Australian perspective and specifically reviews how the various levels of the legal system as they apply to patents—the Australian Patent Office, Australian courts, and Australian government—have dealt with the issue of whether genetic m...

A mechanistic explanation of popularity: genes, rule breaking, and evocative gene-environment correlations.

Science.gov (United States)

Burt, Alexandra

2009-04-01

Previous work has suggested that the serotonergic system plays a key role in "popularity" or likeability. A polymorphism within the 5HT-sub(2A) serotonin receptor gene (-G1438A) has also been associated with popularity, suggesting that genes may predispose individuals to particular social experiences. However, because genes cannot code directly for others' reactions, any legitimate association should be mediated via the individual's behavior (i.e., genes-->behaviors-->social consequences), a phenomenon referred to as an evocative gene-environment correlation (rGE). The current study aimed to identify one such mediating behavior. The author focused on rule breaking given its prior links to both the serotonergic system and to increased popularity during adolescence. Two samples of previously unacquainted late-adolescent boys completed a peer-based interaction paradigm designed to assess their popularity. Analyses revealed that rule breaking partially mediated the genetic effect on popularity, thereby furthering our understanding of the biological mechanisms that underlie popularity. Moreover, the present results represent the first meaningfully explicated evidence that genes predispose individuals not only to particular behaviors but also to the social consequences of those behaviors. (c) 2009 APA, all rights reserved.

A De Novo Whole GCK Gene Deletion Not Detected by Gene Sequencing, in a Boy with Phenotypic GCK Insufficiency

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N. H. Birkebæk

2011-01-01

Full Text Available We report on a boy with diabetes mellitus and a phenotype indicating glucokinase (GCK insufficiency, but a normal GCK gene examination applying direct gene sequencing. The boy was referred for diabetes mellitus at 7.5 years old. His father, grandfather and great grandfather suffered type 2 DM. Several blood glucose profiles showed (BG of 6.5–10 mmol/L L. After three years on neutral insulin Hagedorn (NPH in a dose of 0.3 IU/kg/day haemoglobin A1c (HbA1c was 6.8%. Treatment was changed to sulphonylurea 750 mg a day, and after 4 years HbA1c was 7%. At that time a multiplex ligation-dependent amplification gene dosage assay (MLPA was done, revealing a whole GCK gene deletion. Medical treatment was ceased, and after one year HbA1c was 6.8%. This case underscores the importance of a MLPA examination if the phenotype of a patient is strongly indicative of GCK insufficiency and no mutation is identified using direct sequencing.

Mi-1.2, an R gene for aphid resistance in tomato, has direct negative effects on a zoophytophagous biocontrol agent, Orius insidiosus.

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Pallipparambil, Godshen R; Sayler, Ronald J; Shapiro, Jeffrey P; Thomas, Jean M G; Kring, Timothy J; Goggin, Fiona L

2015-02-01

Mi-1.2 is a single dominant gene in tomato that confers race-specific resistance against certain phloem-feeding herbivores including aphids, whiteflies, psyllids, and root-knot nematodes. Few prior studies have considered the potential non-target effects of race-specific resistance genes (R genes), and this paper evaluates the compatibility of Mi-mediated resistance in tomato with a beneficial zoophytophagous predator, Orius insidiosus (Say). In addition to preying on aphids and other pests, this piercing-sucking insect also feeds from the xylem, epidermis, and/or mesophyll, and oviposits within plant tissues. Comparison of O. insidiosus confined to isogenic tomato plants with and without Mi-1.2 revealed that immatures of O. insidiosus had lower survival on resistant plants even when the immatures were provisioned with prey that did not feed on the host plant. Molecular gut content analysis confirmed that adults and immatures of O. insidiosus feed on both resistant (Mi-1.2+) and susceptible (Mi-1.2-) genotypes, and bioassays suggest that resistance does not affect oviposition rates, plant sampling, or prey acceptance by O. insidiosus adults. These results demonstrate a direct negative impact of R-gene-mediated host plant resistance on a non-target beneficial species, and reveal that Mi-mediated resistance can impact organisms that do not feed on phloem sap. Through laser capture microdissection and RT-PCR, Mi-1.2 transcripts were detected in the epidermis and mesophyll as well as the phloem of tomato plants, consistent with our observations that Mi-mediated resistance is active outside the phloem. These results suggest that the mode of action and potential ecological impacts of Mi-mediated resistance are broader than previously assumed. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Genome-wide identification of KANADI1 target genes.

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Paz Merelo

Full Text Available Plant organ development and polarity establishment is mediated by the action of several transcription factors. Among these, the KANADI (KAN subclade of the GARP protein family plays important roles in polarity-associated processes during embryo, shoot and root patterning. In this study, we have identified a set of potential direct target genes of KAN1 through a combination of chromatin immunoprecipitation/DNA sequencing (ChIP-Seq and genome-wide transcriptional profiling using tiling arrays. Target genes are over-represented for genes involved in the regulation of organ development as well as in the response to auxin. KAN1 affects directly the expression of several genes previously shown to be important in the establishment of polarity during lateral organ and vascular tissue development. We also show that KAN1 controls through its target genes auxin effects on organ development at different levels: transport and its regulation, and signaling. In addition, KAN1 regulates genes involved in the response to abscisic acid, jasmonic acid, brassinosteroids, ethylene, cytokinins and gibberellins. The role of KAN1 in organ polarity is antagonized by HD-ZIPIII transcription factors, including REVOLUTA (REV. A comparison of their target genes reveals that the REV/KAN1 module acts in organ patterning through opposite regulation of shared targets. Evidence of mutual repression between closely related family members is also shown.

Species-independent MicroRNA Gene Discovery

KAUST Repository

Kamanu, Timothy K.

2012-12-01

MicroRNA (miRNA) are a class of small endogenous non-coding RNA that are mainly negative transcriptional and post-transcriptional regulators in both plants and animals. Recent studies have shown that miRNA are involved in different types of cancer and other incurable diseases such as autism and Alzheimer’s. Functional miRNAs are excised from hairpin-like sequences that are known as miRNA genes. There are about 21,000 known miRNA genes, most of which have been determined using experimental methods. miRNA genes are classified into different groups (miRNA families). This study reports about 19,000 unknown miRNA genes in nine species whereby approximately 15,300 predictions were computationally validated to contain at least one experimentally verified functional miRNA product. The predictions are based on a novel computational strategy which relies on miRNA family groupings and exploits the physics and geometry of miRNA genes to unveil the hidden palindromic signals and symmetries in miRNA gene sequences. Unlike conventional computational miRNA gene discovery methods, the algorithm developed here is species-independent: it allows prediction at higher accuracy and resolution from arbitrary RNA/DNA sequences in any species and thus enables examination of repeat-prone genomic regions which are thought to be non-informative or ’junk’ sequences. The information non-redundancy of uni-directional RNA sequences compared to information redundancy of bi-directional DNA is demonstrated, a fact that is overlooked by most pattern discovery algorithms. A novel method for computing upstream and downstream miRNA gene boundaries based on mathematical/statistical functions is suggested, as well as cutoffs for annotation of miRNA genes in different miRNA families. Another tool is proposed to allow hypotheses generation and visualization of data matrices, intra- and inter-species chromosomal distribution of miRNA genes or miRNA families. Our results indicate that: miRNA and mi

Terapia gênica Gene therapy

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Nance Beyer Nardi

2002-01-01

Full Text Available Terapia gênica é um procedimento médico que envolve a modificação genética de células como forma de tratar doenças. Os genes influenciam praticamente todas as doenças humanas, seja pela codificação de proteínas anormais diretamente responsáveis pela doença, seja por determinar suscetibilidade a agentes ambientais que a induzem. A terapia gênica é ainda experimental, e está sendo estudada em protocolos clínicos para diferentes tipos de doenças. O desenvolvimento de métodos seguros e eficientes de transferência gênica para células humanas é um dos pontos mais importantes na terapia gênica. Apesar do grande esforço dirigido na última década para o aperfeiçoamento dos protocolos de terapia gênica humana, e dos avanços importantes na pesquisa básica, as aplicações terapêuticas da tecnologia de transferência gênica continuam ainda em grande parte teóricas. O potencial da terapia gênica é muito grande, devendo ainda causar grande impacto em todos os aspectos da medicina.Gene therapy is a medical intervention that involves modifying the genetic material of living cells to fight disease. Genes influence virtually every human disease, either by encoding for abnormal proteins, which are directly responsible for the disease, or by causing a susceptibility to environmental agents which induce it. Gene therapy is still experimental, and is being studied in clinical trials for many different types of diseases. The development of safe and effective methods of implanting normal genes into the human cell is one of the most important technical issues in gene therapy. Although much effort has been directed in the last decade toward improvement of protocols in human gene therapy, and in spite of many considerable achievements in basic research, the therapeutic applications of gene transfer technology still remain mostly theoretical. The potential for gene therapy is huge and likely to impact on all aspects of medicine.

Direct cloning from enrichment cultures, a reliable strategy for isolation of complete operons and genes from microbial consortia.

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Entcheva, P; Liebl, W; Johann, A; Hartsch, T; Streit, W R

2001-01-01

Enrichment cultures of microbial consortia enable the diverse metabolic and catabolic activities of these populations to be studied on a molecular level and to be explored as potential sources for biotechnology processes. We have used a combined approach of enrichment culture and direct cloning to construct cosmid libraries with large (>30-kb) inserts from microbial consortia. Enrichment cultures were inoculated with samples from five environments, and high amounts of avidin were added to the cultures to favor growth of biotin-producing microbes. DNA was extracted from three of these enrichment cultures and used to construct cosmid libraries; each library consisted of between 6,000 and 35,000 clones, with an average insert size of 30 to 40 kb. The inserts contained a diverse population of genomic DNA fragments isolated from the consortia organisms. These three libraries were used to complement the Escherichia coli biotin auxotrophic strain ATCC 33767 Delta(bio-uvrB). Initial screens resulted in the isolation of seven different complementing cosmid clones, carrying biotin biosynthesis operons. Biotin biosynthesis capabilities and growth under defined conditions of four of these clones were studied. Biotin measured in the different culture supernatants ranged from 42 to 3,800 pg/ml/optical density unit. Sequencing the identified biotin synthesis genes revealed high similarities to bio operons from gram-negative bacteria. In addition, random sequencing identified other interesting open reading frames, as well as two operons, the histidine utilization operon (hut), and the cluster of genes involved in biosynthesis of molybdopterin cofactors in bacteria (moaABCDE).

Horizontal acquisition of multiple mitochondrial genes from a parasitic plant followed by gene conversion with host mitochondrial genes

Science.gov (United States)

2010-01-01

Background Horizontal gene transfer (HGT) is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants. Results In order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR) survey of mitochondrial genes revealed that at least three genes (atp1, atp6 and matR) were recently transferred from Cuscuta to Plantago. Quantitative PCR assays show that these three genes have a mitochondrial location in the one species line of Plantago examined. Patterns of sequence evolution suggest that these foreign genes degraded into pseudogenes shortly after transfer and reverse transcription (RT)-PCR analyses demonstrate that none are detectably transcribed. Three cases of gene conversion were detected between native and foreign copies of the atp1 gene. The identical phylogenetic distribution of the three foreign genes within Plantago and the retention of cytidines at ancestral positions of RNA editing indicate that these genes were probably acquired via a single, DNA-mediated transfer event. However, samplings of multiple individuals from two of the three species in the recipient Plantago clade revealed complex and perplexing phylogenetic discrepancies and patterns of sequence divergence for all three of the foreign genes. Conclusions This study reports the best evidence to date that multiple mitochondrial genes can be transferred via a single HGT event and that transfer occurred via a strictly DNA-level intermediate. The discovery of gene conversion between co-resident foreign and native mitochondrial copies suggests

Horizontal acquisition of multiple mitochondrial genes from a parasitic plant followed by gene conversion with host mitochondrial genes

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Hao Weilong

2010-12-01

Full Text Available Abstract Background Horizontal gene transfer (HGT is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants. Results In order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR survey of mitochondrial genes revealed that at least three genes (atp1, atp6 and matR were recently transferred from Cuscuta to Plantago. Quantitative PCR assays show that these three genes have a mitochondrial location in the one species line of Plantago examined. Patterns of sequence evolution suggest that these foreign genes degraded into pseudogenes shortly after transfer and reverse transcription (RT-PCR analyses demonstrate that none are detectably transcribed. Three cases of gene conversion were detected between native and foreign copies of the atp1 gene. The identical phylogenetic distribution of the three foreign genes within Plantago and the retention of cytidines at ancestral positions of RNA editing indicate that these genes were probably acquired via a single, DNA-mediated transfer event. However, samplings of multiple individuals from two of the three species in the recipient Plantago clade revealed complex and perplexing phylogenetic discrepancies and patterns of sequence divergence for all three of the foreign genes. Conclusions This study reports the best evidence to date that multiple mitochondrial genes can be transferred via a single HGT event and that transfer occurred via a strictly DNA-level intermediate. The discovery of gene conversion between co-resident foreign and native

Consensus strategy in genes prioritization and combined bioinformatics analysis for preeclampsia pathogenesis.

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Tejera, Eduardo; Cruz-Monteagudo, Maykel; Burgos, Germán; Sánchez, María-Eugenia; Sánchez-Rodríguez, Aminael; Pérez-Castillo, Yunierkis; Borges, Fernanda; Cordeiro, Maria Natália Dias Soeiro; Paz-Y-Miño, César; Rebelo, Irene

2017-08-08

Preeclampsia is a multifactorial disease with unknown pathogenesis. Even when recent studies explored this disease using several bioinformatics tools, the main objective was not directed to pathogenesis. Additionally, consensus prioritization was proved to be highly efficient in the recognition of genes-disease association. However, not information is available about the consensus ability to early recognize genes directly involved in pathogenesis. Therefore our aim in this study is to apply several theoretical approaches to explore preeclampsia; specifically those genes directly involved in the pathogenesis. We firstly evaluated the consensus between 12 prioritization strategies to early recognize pathogenic genes related to preeclampsia. A communality analysis in the protein-protein interaction network of previously selected genes was done including further enrichment analysis. The enrichment analysis includes metabolic pathways as well as gene ontology. Microarray data was also collected and used in order to confirm our results or as a strategy to weight the previously enriched pathways. The consensus prioritized gene list was rationally filtered to 476 genes using several criteria. The communality analysis showed an enrichment of communities connected with VEGF-signaling pathway. This pathway is also enriched considering the microarray data. Our result point to VEGF, FLT1 and KDR as relevant pathogenic genes, as well as those connected with NO metabolism. Our results revealed that consensus strategy improve the detection and initial enrichment of pathogenic genes, at least in preeclampsia condition. Moreover the combination of the first percent of the prioritized genes with protein-protein interaction network followed by communality analysis reduces the gene space. This approach actually identifies well known genes related with pathogenesis. However, genes like HSP90, PAK2, CD247 and others included in the first 1% of the prioritized list need to be further

Do GnRH analogues directly affect human endometrial epithelial cell gene expression?

KAUST Repository

Zhang, Xiaomei; Bocca, Silvina Maria; Franchi, Anahí ; Anderson, Sandra; Kaur, Mandeep; Bajic, Vladimir B.; Oehninger, Sergio Carlos

2010-01-01

were: (i) to study the modulatory effect of GnRH analogues by RT-PCR [in the absence and presence of E2 and P4, and cyclic adenosine monophos-phate (cAMP)] on mRNA expression of genes modulated during the window of implantation in GnRH analogues

Regulating Hypothalamus Gene Expression in Food Intake: Dietary Composition or Calorie Density?

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Mi Jang

2017-01-01

Full Text Available BackgroundThe proportion of saturated fatty acids/unsaturated fatty acids in the diet seems to act as a physiological regulation on obesity, cardiovascular diseases, and diabetes. Differently composed fatty acid diets may induce satiety of the hypothalamus in different ways. However, the direct effect of the different fatty acid diets on satiety in the hypothalamus is not clear.MethodsThree experiments in mice were conducted to determine whether: different compositions of fatty acids affects gene mRNA expression of the hypothalamus over time; different types of fatty acids administered into the stomach directly affect gene mRNA expression of the hypothalamus; and fat composition changes in the diet affects gene mRNA expression of the hypothalamus.ResultsThe type of fat in cases of purified fatty acid administration directly into the stomach may cause changes of gene expressions in the hypothalamus. Gene expression by dietary fat may be regulated by calorie amount ingested rather than weight amount or type of fat.ConclusionTherefore, the calorie density factor of the diet in regulating hypothalamic gene in food intake may be detrimental, although the possibility of type of fat cannot be ruled out.

Characterisation of genome-wide PLZF/RARA target genes.

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Salvatore Spicuglia

Full Text Available The PLZF/RARA fusion protein generated by the t(11;17(q23;q21 translocation in acute promyelocytic leukaemia (APL is believed to act as an oncogenic transcriptional regulator recruiting epigenetic factors to genes important for its transforming potential. However, molecular mechanisms associated with PLZF/RARA-dependent leukaemogenesis still remain unclear.We searched for specific PLZF/RARA target genes by ChIP-on-chip in the haematopoietic cell line U937 conditionally expressing PLZF/RARA. By comparing bound regions found in U937 cells expressing endogenous PLZF with PLZF/RARA-induced U937 cells, we isolated specific PLZF/RARA target gene promoters. We next analysed gene expression profiles of our identified target genes in PLZF/RARA APL patients and analysed DNA sequences and epigenetic modification at PLZF/RARA binding sites. We identify 413 specific PLZF/RARA target genes including a number encoding transcription factors involved in the regulation of haematopoiesis. Among these genes, 22 were significantly down regulated in primary PLZF/RARA APL cells. In addition, repressed PLZF/RARA target genes were associated with increased levels of H3K27me3 and decreased levels of H3K9K14ac. Finally, sequence analysis of PLZF/RARA bound sequences reveals the presence of both consensus and degenerated RAREs as well as enrichment for tissue-specific transcription factor motifs, highlighting the complexity of targeting fusion protein to chromatin. Our study suggests that PLZF/RARA directly targets genes important for haematopoietic development and supports the notion that PLZF/RARA acts mainly as an epigenetic regulator of its direct target genes.

The Hos2 Histone Deacetylase Controls Ustilago maydis Virulence through Direct Regulation of Mating-Type Genes.

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Alberto Elías-Villalobos

2015-08-01

Full Text Available Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.

Theranostic Imaging of Cancer Gene Therapy.

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Sekar, Thillai V; Paulmurugan, Ramasamy

2016-01-01

Gene-directed enzyme prodrug therapy (GDEPT) is a promising therapeutic approach for treating cancers of various phenotypes. This strategy is independent of various other chemotherapeutic drugs used for treating cancers where the drugs are mainly designed to target endogenous cellular mechanisms, which are different in various cancer subtypes. In GDEPT an external enzyme, which is different from the cellular proteins, is expressed to convert the injected prodrug in to a toxic metabolite, that normally kill cancer cells express this protein. Theranostic imaging is an approach used to directly monitor the expression of these gene therapy enzymes while evaluating therapeutic effect. We recently developed a dual-GDEPT system where we combined mutant human herpes simplex thymidine kinase (HSV1sr39TK) and E. coli nitroreductase (NTR) enzyme, to improve therapeutic efficiency of cancer gene therapy by simultaneously injecting two prodrugs at a lower dose. In this approach we use two different prodrugs such as ganciclovir (GCV) and CB1954 to target two different cellular mechanisms to kill cancer cells. The developed dual GDEPT system was highly efficacious than that of either of the system used independently. In this chapter, we describe the complete protocol involved for in vitro and in vivo imaging of therapeutic cancer gene therapy evaluation.

Text mining in cancer gene and pathway prioritization.

Science.gov (United States)

Luo, Yuan; Riedlinger, Gregory; Szolovits, Peter

2014-01-01

Prioritization of cancer implicated genes has received growing attention as an effective way to reduce wet lab cost by computational analysis that ranks candidate genes according to the likelihood that experimental verifications will succeed. A multitude of gene prioritization tools have been developed, each integrating different data sources covering gene sequences, differential expressions, function annotations, gene regulations, protein domains, protein interactions, and pathways. This review places existing gene prioritization tools against the backdrop of an integrative Omic hierarchy view toward cancer and focuses on the analysis of their text mining components. We explain the relatively slow progress of text mining in gene prioritization, identify several challenges to current text mining methods, and highlight a few directions where more effective text mining algorithms may improve the overall prioritization task and where prioritizing the pathways may be more desirable than prioritizing only genes.

Genes essential for phototrophic growth by a purple alphaproteobacterium: Genes for phototrophic growth

Energy Technology Data Exchange (ETDEWEB)

Yang, Jianming [Key Lab of Applied Mycology, College of Life Sciences, Qingdao Agricultural University, Qingdao Shandong Province People' s Republic of China; Department of Microbiology, University of Washington, Seattle WA USA; Yin, Liang [Department of Microbiology, University of Washington, Seattle WA USA; Lessner, Faith H. [Department of Biological Sciences, University of Arkansas, Fayetteville AR USA; Nakayasu, Ernesto S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA USA; Payne, Samuel H. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA USA; Fixen, Kathryn R. [Department of Microbiology, University of Washington, Seattle WA USA; Gallagher, Larry [Department of Genome Sciences, University of Washington, Seattle WA USA; Harwood, Caroline S. [Department of Microbiology, University of Washington, Seattle WA USA

2017-07-24

Anoxygenic purple phototrophic bacteria have served as important models for studies of photophosphorylation. The pigment-protein complexes responsible for converting light energy to ATP are relatively simple and these bacteria can grow heterotrophically under aerobic conditions, thus allowing for the study of mutants defective in photophosphorylation. In the past, genes responsible for anoxygenic phototrophic growth have been identified in a number of different bacterial species. Here we systematically studied the genetic basis for this metabolism by using Tn-seq to identify genes essential for the anaerobic growth of the purple bacterium Rhodopseudomonas palustris on acetate in light. We identified 171 genes required for growth in this condition, 35 of which are annotated as photosynthesis genes. Among these are a few new genes not previously shown to be essential for phototrophic growth. We verified the essentiality of many of the genes we identified by analyzing the phenotypes of mutants we generated by Tn mutagenesis that had altered pigmentation. We used directed mutagenesis to verify that the R. palustris NADH:quinone oxidoreductase complex IE is essential for phototrophic growth. As a complement to the genetic data, we carried out proteomics experiments in which we found that 429 proteins were present in significantly higher amounts in cells grown anaerobically in light compared to aerobically. Among these were proteins encoded by subset of the phototrophic growth-essential genes.

Immune genes undergo more adaptive evolution than non-immune system genes in Daphnia pulex

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McTaggart Seanna J

2012-05-01

Full Text Available Abstract Background Understanding which parts of the genome have been most influenced by adaptive evolution remains an unsolved puzzle. Some evidence suggests that selection has the greatest impact on regions of the genome that interact with other evolving genomes, including loci that are involved in host-parasite co-evolutionary processes. In this study, we used a population genetic approach to test this hypothesis by comparing DNA sequences of 30 putative immune system genes in the crustacean Daphnia pulex with 24 non-immune system genes. Results In support of the hypothesis, results from a multilocus extension of the McDonald-Kreitman (MK test indicate that immune system genes as a class have experienced more adaptive evolution than non-immune system genes. However, not all immune system genes show evidence of adaptive evolution. Additionally, we apply single locus MK tests and calculate population genetic parameters at all loci in order to characterize the mode of selection (directional versus balancing in the genes that show the greatest deviation from neutral evolution. Conclusions Our data are consistent with the hypothesis that immune system genes undergo more adaptive evolution than non-immune system genes, possibly as a result of host-parasite arms races. The results of these analyses highlight several candidate loci undergoing adaptive evolution that could be targeted in future studies.

Gene expression profiling of brakeless mutant Drosophila embryos.

Science.gov (United States)

Crona, Filip; Singla, Bhumica; Mannervik, Mattias

2015-12-01

The transcriptional co-regulator Brakeless performs many important functions during Drosophila development, but few target genes have been identified. Here we use Affymetrix microarrays to identify Brakeless-regulated genes in 2-4 h old Drosophila embryos. Robust multi-array analysis (RMA) and statistical tests revealed 240 genes that changed their expression more than 1.5 fold. We find that up- and down-regulated genes fall into distinct gene ontology categories. In our associated study [2] we demonstrate that both up- and down-regulated genes can be direct Brakeless targets. Our results indicate that the co-repressor and co-activator activities of Brakeless may result in distinct biological responses. The microarray data complies with MIAME guidelines and is deposited in GEO under accession number GSE60048.

Opposite replication polarities of transcribed and nontranscribed histone H5 genes

International Nuclear Information System (INIS)

Trempe, J.P.; Lindstrom, Y.I.; Leffak, M.

1988-01-01

The authors used an in vitro nuclear runoff replication assay to analyze the direction of replication of the active and inactive histone H5 genes in avian cells. In embryonic erythrocytes the transcribed histone H5 gene displayed sensitivity to endogenous nuclease cleavage. In contrast, this gene was insensitive to endogenous nuclease digestion under the same conditions in nuclei of the lymphoblastoid cell line MSB-1, and histone H5 gene transcripts were not detectable by dot-blot analysis of MSB-1 cell RNA. When nuclei were isolated from embryonic erythrocyctes and incubated with bromodeoxyuridine triphosphate, runoff replication from endogenous nuclease cleavage sites led to a relative enrichment for fragments near the 3' end of the histone H5 gene in the density-labeled DNA. In nuclei of MSB-1 cells or chicken embryo fibroblasts, however, runoff replication from restriction enzyme-cut sites (or induced endogenous nuclease-cut sites in MSB-1 nuclei) led to a relative enrichment for fragments near the 5' end of the H5 gene in dense DNA. Based on the enhanced incorporation of bromodeoxyuridine into origin-distal regions of DNA during the in vitro runoff replication assay, the authors conclude that the active histone H5 gene in embryonic erythrocytes is preferentially replicated in the transcriptional direction from an origin in the 5'-flanking DNA, whereas its inactive counterparts in MSB-1 cells and chicken embryo fibroblasts are preferentially replicated in the opposite direction

Gene expression network reconstruction by convex feature selection when incorporating genetic perturbations.

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Benjamin A Logsdon

Full Text Available Cellular gene expression measurements contain regulatory information that can be used to discover novel network relationships. Here, we present a new algorithm for network reconstruction powered by the adaptive lasso, a theoretically and empirically well-behaved method for selecting the regulatory features of a network. Any algorithms designed for network discovery that make use of directed probabilistic graphs require perturbations, produced by either experiments or naturally occurring genetic variation, to successfully infer unique regulatory relationships from gene expression data. Our approach makes use of appropriately selected cis-expression Quantitative Trait Loci (cis-eQTL, which provide a sufficient set of independent perturbations for maximum network resolution. We compare the performance of our network reconstruction algorithm to four other approaches: the PC-algorithm, QTLnet, the QDG algorithm, and the NEO algorithm, all of which have been used to reconstruct directed networks among phenotypes leveraging QTL. We show that the adaptive lasso can outperform these algorithms for networks of ten genes and ten cis-eQTL, and is competitive with the QDG algorithm for networks with thirty genes and thirty cis-eQTL, with rich topologies and hundreds of samples. Using this novel approach, we identify unique sets of directed relationships in Saccharomyces cerevisiae when analyzing genome-wide gene expression data for an intercross between a wild strain and a lab strain. We recover novel putative network relationships between a tyrosine biosynthesis gene (TYR1, and genes involved in endocytosis (RCY1, the spindle checkpoint (BUB2, sulfonate catabolism (JLP1, and cell-cell communication (PRM7. Our algorithm provides a synthesis of feature selection methods and graphical model theory that has the potential to reveal new directed regulatory relationships from the analysis of population level genetic and gene expression data.

Mutated genes as research tool

International Nuclear Information System (INIS)

1981-01-01

Green plants are the ultimate source of all resources required for man's life, his food, his clothes, and almost all his energy requirements. Primitive prehistoric man could live from the abundance of nature surrounding him. Man today, dominating nature in terms of numbers and exploiting its limited resources, cannot exist without employing his intelligence to direct natural evolution. Plant sciences, therefore, are not a matter of curiosity but an essential requirement. From such considerations, the IAEA and FAO jointly organized a symposium to assess the value of mutation research for various kinds of plant science, which directly or indirectly might contribute to sustaining and improving crop production. The benefit through developing better cultivars that plant breeders can derive from using the additional genetic resources resulting from mutation induction has been assessed before at other FAO/IAEA meetings (Rome 1964, Pullman 1969, Ban 1974, Ibadan 1978) and is also monitored in the Mutation Breeding Newsletter, published by IAEA twice a year. Several hundred plant cultivars which carry economically important characters because their genes have been altered by ionizing radiation or other mutagens, are grown by farmers and horticulturists in many parts of the world. But the benefit derived from such mutant varieties is without any doubt surpassed by the contribution which mutation research has made towards the advancement of genetics. For this reason, a major part of the papers and discussions at the symposium dealt with the role induced-mutation research played in providing insight into gene action and gene interaction, the organization of genes in plant chromosomes in view of homology and homoeology, the evolutionary role of gene duplication and polyploidy, the relevance of gene blocks, the possibilities for chromosome engineering, the functioning of cytroplasmic inheritance and the genetic dynamics of populations. In discussing the evolutionary role of

Identification of Human HK Genes and Gene Expression Regulation Study in Cancer from Transcriptomics Data Analysis

Science.gov (United States)

Zhang, Zhang; Liu, Jingxing; Wu, Jiayan; Yu, Jun

2013-01-01

The regulation of gene expression is essential for eukaryotes, as it drives the processes of cellular differentiation and morphogenesis, leading to the creation of different cell types in multicellular organisms. RNA-Sequencing (RNA-Seq) provides researchers with a powerful toolbox for characterization and quantification of transcriptome. Many different human tissue/cell transcriptome datasets coming from RNA-Seq technology are available on public data resource. The fundamental issue here is how to develop an effective analysis method to estimate expression pattern similarities between different tumor tissues and their corresponding normal tissues. We define the gene expression pattern from three directions: 1) expression breadth, which reflects gene expression on/off status, and mainly concerns ubiquitously expressed genes; 2) low/high or constant/variable expression genes, based on gene expression level and variation; and 3) the regulation of gene expression at the gene structure level. The cluster analysis indicates that gene expression pattern is higher related to physiological condition rather than tissue spatial distance. Two sets of human housekeeping (HK) genes are defined according to cell/tissue types, respectively. To characterize the gene expression pattern in gene expression level and variation, we firstly apply improved K-means algorithm and a gene expression variance model. We find that cancer-associated HK genes (a HK gene is specific in cancer group, while not in normal group) are expressed higher and more variable in cancer condition than in normal condition. Cancer-associated HK genes prefer to AT-rich genes, and they are enriched in cell cycle regulation related functions and constitute some cancer signatures. The expression of large genes is also avoided in cancer group. These studies will help us understand which cell type-specific patterns of gene expression differ among different cell types, and particularly for cancer. PMID:23382867

Cis-regulatory timers for developmental gene expression.

Directory of Open Access Journals (Sweden)

Lionel Christiaen

2013-10-01

Full Text Available How does a fertilized egg decode its own genome to eventually develop into a mature animal? Each developing cell must activate a battery of genes in a timely manner and according to the function it will ultimately perform, but how? During development of the notochord--a structure akin to the vertebrate spine--in a simple marine invertebrate, an essential protein called Brachyury binds to specific sites in its target genes. A study just published in PLOS Biology reports that if the target gene contains multiple Brachyury-binding sites it will be activated early in development but if it contains only one site it will be activated later. Genes that contain no binding site can still be activated by Brachyury, but only indirectly by an earlier Brachyury-dependent gene product, so later than the directly activated genes. Thus, this study shows how several genes can interpret the presence of a single factor differently to become active at distinct times in development.

Adaptive Evolution of Gene Expression in Drosophila.

Science.gov (United States)

Nourmohammad, Armita; Rambeau, Joachim; Held, Torsten; Kovacova, Viera; Berg, Johannes; Lässig, Michael

2017-08-08

Gene expression levels are important quantitative traits that link genotypes to molecular functions and fitness. In Drosophila, population-genetic studies have revealed substantial adaptive evolution at the genomic level, but the evolutionary modes of gene expression remain controversial. Here, we present evidence that adaptation dominates the evolution of gene expression levels in flies. We show that 64% of the observed expression divergence across seven Drosophila species are adaptive changes driven by directional selection. Our results are derived from time-resolved data of gene expression divergence across a family of related species, using a probabilistic inference method for gene-specific selection. Adaptive gene expression is stronger in specific functional classes, including regulation, sensory perception, sexual behavior, and morphology. Moreover, we identify a large group of genes with sex-specific adaptation of expression, which predominantly occurs in males. Our analysis opens an avenue to map system-wide selection on molecular quantitative traits independently of their genetic basis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Adaptive Evolution of Gene Expression in Drosophila

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Armita Nourmohammad

2017-08-01

Full Text Available Gene expression levels are important quantitative traits that link genotypes to molecular functions and fitness. In Drosophila, population-genetic studies have revealed substantial adaptive evolution at the genomic level, but the evolutionary modes of gene expression remain controversial. Here, we present evidence that adaptation dominates the evolution of gene expression levels in flies. We show that 64% of the observed expression divergence across seven Drosophila species are adaptive changes driven by directional selection. Our results are derived from time-resolved data of gene expression divergence across a family of related species, using a probabilistic inference method for gene-specific selection. Adaptive gene expression is stronger in specific functional classes, including regulation, sensory perception, sexual behavior, and morphology. Moreover, we identify a large group of genes with sex-specific adaptation of expression, which predominantly occurs in males. Our analysis opens an avenue to map system-wide selection on molecular quantitative traits independently of their genetic basis.

A relative variation-based method to unraveling gene regulatory networks.

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Yali Wang

Full Text Available Gene regulatory network (GRN reconstruction is essential in understanding the functioning and pathology of a biological system. Extensive models and algorithms have been developed to unravel a GRN. The DREAM project aims to clarify both advantages and disadvantages of these methods from an application viewpoint. An interesting yet surprising observation is that compared with complicated methods like those based on nonlinear differential equations, etc., methods based on a simple statistics, such as the so-called Z-score, usually perform better. A fundamental problem with the Z-score, however, is that direct and indirect regulations can not be easily distinguished. To overcome this drawback, a relative expression level variation (RELV based GRN inference algorithm is suggested in this paper, which consists of three major steps. Firstly, on the basis of wild type and single gene knockout/knockdown experimental data, the magnitude of RELV of a gene is estimated. Secondly, probability for the existence of a direct regulation from a perturbed gene to a measured gene is estimated, which is further utilized to estimate whether a gene can be regulated by other genes. Finally, the normalized RELVs are modified to make genes with an estimated zero in-degree have smaller RELVs in magnitude than the other genes, which is used afterwards in queuing possibilities of the existence of direct regulations among genes and therefore leads to an estimate on the GRN topology. This method can in principle avoid the so-called cascade errors under certain situations. Computational results with the Size 100 sub-challenges of DREAM3 and DREAM4 show that, compared with the Z-score based method, prediction performances can be substantially improved, especially the AUPR specification. Moreover, it can even outperform the best team of both DREAM3 and DREAM4. Furthermore, the high precision of the obtained most reliable predictions shows that the suggested algorithm may be

Transcriptomic and genetic analysis of direct interspecies electron transfer

DEFF Research Database (Denmark)

Shrestha, Pravin Malla; Rotaru, Amelia-Elena; Summers, Zarath M

2013-01-01

The possibility that metatranscriptomic analysis could distinguish between direct interspecies electron transfer (DIET) and H2 interspecies transfer (HIT) in anaerobic communities was investigated by comparing gene transcript abundance in cocultures in which Geobacter sulfurreducens....... These results demonstrate that there are unique gene expression patterns that distinguish DIET from HIT and suggest that metatranscriptomics may be a promising route to investigate interspecies electron transfer pathways in more-complex environments....

Principles for the organization of gene-sets.

Science.gov (United States)

Li, Wentian; Freudenberg, Jan; Oswald, Michaela

2015-12-01

A gene-set, an important concept in microarray expression analysis and systems biology, is a collection of genes and/or their products (i.e. proteins) that have some features in common. There are many different ways to construct gene-sets, but a systematic organization of these ways is lacking. Gene-sets are mainly organized ad hoc in current public-domain databases, with group header names often determined by practical reasons (such as the types of technology in obtaining the gene-sets or a balanced number of gene-sets under a header). Here we aim at providing a gene-set organization principle according to the level at which genes are connected: homology, physical map proximity, chemical interaction, biological, and phenotypic-medical levels. We also distinguish two types of connections between genes: actual connection versus sharing of a label. Actual connections denote direct biological interactions, whereas shared label connection denotes shared membership in a group. Some extensions of the framework are also addressed such as overlapping of gene-sets, modules, and the incorporation of other non-protein-coding entities such as microRNAs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Highly specific expression of luciferase gene in lungs of naive nude mice directed by prostate-specific antigen promoter

International Nuclear Information System (INIS)

Li Hongwei; Li Jinzhong; Helm, Gregory A.; Pan Dongfeng

2005-01-01

PSA promoter has been demonstrated the utility for tissue-specific toxic gene therapy in prostate cancer models. Characterization of foreign gene overexpression in normal animals elicited by PSA promoter should help evaluate therapy safety. Here we constructed an adenovirus vector (AdPSA-Luc), containing firefly luciferase gene under the control of the 5837 bp long prostate-specific antigen promoter. A charge coupled device video camera was used to non-invasively image expression of firefly luciferase in nude mice on days 3, 7, 11 after injection of 2 x 10 9 PFU of AdPSA-Luc virus via tail vein. The result showed highly specific expression of the luciferase gene in lungs of mice from day 7. The finding indicates the potential limitations of the suicide gene therapy of prostate cancer based on selectivity of PSA promoter. By contrary, it has encouraging implications for further development of vectors via PSA promoter to enable gene therapy for pulmonary diseases

A gene network bioinformatics analysis for pemphigoid autoimmune blistering diseases.

Science.gov (United States)

Barone, Antonio; Toti, Paolo; Giuca, Maria Rita; Derchi, Giacomo; Covani, Ugo

2015-07-01

In this theoretical study, a text mining search and clustering analysis of data related to genes potentially involved in human pemphigoid autoimmune blistering diseases (PAIBD) was performed using web tools to create a gene/protein interaction network. The Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database was employed to identify a final set of PAIBD-involved genes and to calculate the overall significant interactions among genes: for each gene, the weighted number of links, or WNL, was registered and a clustering procedure was performed using the WNL analysis. Genes were ranked in class (leader, B, C, D and so on, up to orphans). An ontological analysis was performed for the set of 'leader' genes. Using the above-mentioned data network, 115 genes represented the final set; leader genes numbered 7 (intercellular adhesion molecule 1 (ICAM-1), interferon gamma (IFNG), interleukin (IL)-2, IL-4, IL-6, IL-8 and tumour necrosis factor (TNF)), class B genes were 13, whereas the orphans were 24. The ontological analysis attested that the molecular action was focused on extracellular space and cell surface, whereas the activation and regulation of the immunity system was widely involved. Despite the limited knowledge of the present pathologic phenomenon, attested by the presence of 24 genes revealing no protein-protein direct or indirect interactions, the network showed significant pathways gathered in several subgroups: cellular components, molecular functions, biological processes and the pathologic phenomenon obtained from the Kyoto Encyclopaedia of Genes and Genomes (KEGG) database. The molecular basis for PAIBD was summarised and expanded, which will perhaps give researchers promising directions for the identification of new therapeutic targets.

Gene Expression and Polymorphism of Myostatin Gene and its Association with Growth Traits in Chicken.

Science.gov (United States)

Dushyanth, K; Bhattacharya, T K; Shukla, R; Chatterjee, R N; Sitaramamma, T; Paswan, C; Guru Vishnu, P

2016-10-01

Myostatin is a member of TGF-β super family and is directly involved in regulation of body growth through limiting muscular growth. A study was carried out in three chicken lines to identify the polymorphism in the coding region of the myostatin gene through SSCP and DNA sequencing. A total of 12 haplotypes were observed in myostatin coding region of chicken. Significant associations between haplogroups with body weight at day 1, 14, 28, and 42 days, and carcass traits at 42 days were observed across the lines. It is concluded that the coding region of myostatin gene was polymorphic, with varied levels of expression among lines and had significant effects on growth traits. The expression of MSTN gene varied during embryonic and post hatch development stage.

Advances in directed monooxygenase evolution : from diversity generation and flow cytometry screening to tailor-made monooxygenases

OpenAIRE

Ruff, Anna Joëlle

2012-01-01

Directed Evolution became a powerful tool for proteins engineers to generate tailor-made biocatalyst. Directed protein evolution consist of the following three consecutive main steps, which are performed in iterative cycles; Step 1 the gene diversity generation, Step 2 the screening for improved variants and Step 3 the isolation of gene encoding for improved proteins. In this thesis, methodological advancements in the two key steps of the directed evolution, the diversity generation (SeSaM me...

Gene prediction validation and functional analysis of redundant pathways

DEFF Research Database (Denmark)

Sønderkær, Mads

2011-01-01

have employed a large mRNA-seq data set to improve and validate ab initio predicted gene models. This direct experimental evidence also provides reliable determinations of UTR regions and polyadenylation sites, which are not easily predicted in plants. Furthermore, once an annotated genome sequence...... is available, gene expression by mRNA-Seq enables acquisition of a more complete overview of gene isoform usage in complex enzymatic pathways enabling the identification of key genes. Metabolism in potatoes This information is useful e.g. for crop improvement based on manipulation of agronomically important...

A locked nucleic acid (LNA-based real-time PCR assay for the rapid detection of multiple bacterial antibiotic resistance genes directly from positive blood culture.

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Lingxiang Zhu

Full Text Available Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA-based quantitative real-time PCR (LNA-qPCR method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1-10 colony forming units (CFU per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4% were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.

Epstein-Barr Virus (EBV) Latent Protein EBNA3A Directly Targets and Silences the STK39 Gene in B Cells Infected by EBV.

Science.gov (United States)

Bazot, Quentin; Paschos, Kostas; Allday, Martin J

2018-04-01

Epstein-Barr virus (EBV) establishes latent infection in human B cells and is associated with a wide range of cancers. The EBV nuclear antigen 3 (EBNA3) family proteins are critical for B cell transformation and function as transcriptional regulators. It is well established that EBNA3A and EBNA3C cooperate in the regulation of cellular genes. Here, we demonstrate that the gene STK39 is repressed only by EBNA3A. This is the first example of a gene regulated only by EBNA3A in EBV-transformed lymphoblastoid cell lines (LCLs) without the help of EBNA3C. This was demonstrated using a variety of LCLs carrying either knockout, revertant, or conditional EBNA3 recombinants. Investigating the kinetics of EBNA3A-mediated changes in STK39 expression showed that STK39 becomes derepressed quickly after EBNA3A inactivation. This derepression is reversible as EBNA3A reactivation represses STK39 in the same cells expressing a conditional EBNA3A. STK39 is silenced shortly after primary B cell infection by EBV, and no STK39 -encoded protein (SPAK) is detected 3 weeks postinfection. Chromatin immunoprecipitation (ChIP) analysis indicates that EBNA3A directly binds to a regulatory region downstream of the STK39 transcription start site. For the first time, we demonstrated that the polycomb repressive complex 2 with the deposition of the repressive mark H3K27me3 is not only important for the maintenance of an EBNA3A target gene ( STK39 ) but is also essential for the initial establishment of its silencing. Finally, we showed that DNA methyltransferases are involved in the EBNA3A-mediated repression of STK39 IMPORTANCE EBV is well known for its ability to transform B lymphocytes to continuously proliferating lymphoblastoid cell lines. This is achieved in part by the reprogramming of cellular gene transcription by EBV transcription factors, including the EBNA3 proteins that play a crucial role in this process. In the present study, we found that EBNA3A epigenetically silences STK39 This

Identification of direct regulatory targets of the transcription factor Sox10 based on function and conservation

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Lee Sanghyuk

2008-09-01

Full Text Available Abstract Background Sox10, a member of the Sry-related HMG-Box gene family, is a critical transcription factor for several important cell lineages, most notably the neural crest stem cells and the derivative peripheral glial cells and melanocytes. Thus far, only a handful of direct target genes are known for this transcription factor limiting our understanding of the biological network it governs. Results We describe identification of multiple direct regulatory target genes of Sox10 through a procedure based on function and conservation. By combining RNA interference technique and DNA microarray technology, we have identified a set of genes that show significant down-regulation upon introduction of Sox10 specific siRNA into Schwannoma cells. Subsequent comparative genomics analyses led to potential binding sites for Sox10 protein conserved across several mammalian species within the genomic region proximal to these genes. Multiple sites belonging to 4 different genes (proteolipid protein, Sox10, extracellular superoxide dismutase, and pleiotrophin were shown to directly interact with Sox10 by chromatin immunoprecipitation assay. We further confirmed the direct regulation through the identified cis-element for one of the genes, extracellular superoxide dismutase, using electrophoretic mobility shift assay and reporter assay. Conclusion In sum, the process of combining differential expression profiling and comparative genomics successfully led to further defining the role of Sox10, a critical transcription factor for the development of peripheral glia. Our strategy utilizing relatively accessible techniques and tools should be applicable to studying the function of other transcription factors.

Gene Overexpression Resources in Cereals for Functional Genomics and Discovery of Useful Genes

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Kiyomi Abe

2016-09-01

Full Text Available Identification and elucidation of functions of plant genes is valuable for both basic and applied research. In addition to natural variation in model plants, numerous loss-of-function resources have been produced by mutagenesis with chemicals, irradiation, or insertions of transposable elements or T-DNA. However, we may be unable to observe loss-of-function phenotypes for genes with functionally redundant homologs, and for those essential for growth and development. To offset such disadvantages, gain-of-function transgenic resources have been exploited. Activation-tagged lines have been generated using obligatory overexpression of endogenous genes by random insertion of an enhancer. Recent progress in DNA sequencing technology and bioinformatics has enabled the preparation of genomewide collections of full-length cDNAs (fl-cDNAs in some model species. Using the fl-cDNA clones, a novel gain-of-function strategy, Fl-cDNA OvereXpressor gene (FOX-hunting system, has been developed. A mutant phenotype in a FOX line can be directly attributed to the overexpressed fl-cDNA. Investigating a large population of FOX lines could reveal important genes conferring favorable phenotypes for crop breeding. Alternatively, a unique loss-of-function approach Chimeric REpressor gene Silencing Technology (CRES-T has been developed. In CRES-T, overexpression of a chimeric repressor, composed of the coding sequence of a transcription factor (TF and short peptide designated as the repression domain, could interfere with the action of endogenous TF in plants. Although plant TFs usually consist of gene families, CRES-T is effective, in principle, even for the TFs with functional redundancy. In this review, we focus on the current status of the gene-overexpression strategies and resources for identifying and elucidating novel functions of cereal genes. We discuss the potential of these research tools for identifying useful genes and phenotypes for application in crop

Gene dosage induction of silencing directed against an Arabidopsis Myb transgene in tobacco

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An unexpected reduction in petal pigmentation on petunia plants genetically engineered for enhanced flower color was one of the first experimental demonstrations of the natural process of RNA-associated gene silencing. The obvious visual nature of such alterations to pigment patterns of transgenic ...

Rather than by direct acquisition via lateral gene transfer, GHF5 cellulases were passed on from early Pratylenchidae to root-knot and cyst nematodes.

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Rybarczyk-Mydłowska, Katarzyna; Maboreke, Hazel Ruvimbo; van Megen, Hanny; van den Elsen, Sven; Mooyman, Paul; Smant, Geert; Bakker, Jaap; Helder, Johannes

2012-11-21

Plant parasitic nematodes are unusual Metazoans as they are equipped with genes that allow for symbiont-independent degradation of plant cell walls. Among the cell wall-degrading enzymes, glycoside hydrolase family 5 (GHF5) cellulases are relatively well characterized, especially for high impact parasites such as root-knot and cyst nematodes. Interestingly, ancestors of extant nematodes most likely acquired these GHF5 cellulases from a prokaryote donor by one or multiple lateral gene transfer events. To obtain insight into the origin of GHF5 cellulases among evolutionary advanced members of the order Tylenchida, cellulase biodiversity data from less distal family members were collected and analyzed. Single nematodes were used to obtain (partial) genomic sequences of cellulases from representatives of the genera Meloidogyne, Pratylenchus, Hirschmanniella and Globodera. Combined Bayesian analysis of ≈ 100 cellulase sequences revealed three types of catalytic domains (A, B, and C). Represented by 84 sequences, type B is numerically dominant, and the overall topology of the catalytic domain type shows remarkable resemblance with trees based on neutral (= pathogenicity-unrelated) small subunit ribosomal DNA sequences. Bayesian analysis further suggested a sister relationship between the lesion nematode Pratylenchus thornei and all type B cellulases from root-knot nematodes. Yet, the relationship between the three catalytic domain types remained unclear. Superposition of intron data onto the cellulase tree suggests that types B and C are related, and together distinct from type A that is characterized by two unique introns. All Tylenchida members investigated here harbored one or multiple GHF5 cellulases. Three types of catalytic domains are distinguished, and the presence of at least two types is relatively common among plant parasitic Tylenchida. Analysis of coding sequences of cellulases suggests that root-knot and cyst nematodes did not acquire this gene directly

Rather than by direct acquisition via lateral gene transfer, GHF5 cellulases were passed on from early Pratylenchidae to root-knot and cyst nematodes

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Rybarczyk-Mydłowska Katarzyna

2012-11-01

-knot and cyst nematodes did not acquire this gene directly by lateral genes transfer. More likely, these genes were passed on by ancestors of a family nowadays known as the Pratylenchidae.

Directed Evolution of Proteins through In Vitro Protein Synthesis in Liposomes

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Takehiro Nishikawa

2012-01-01

Full Text Available Directed evolution of proteins is a technique used to modify protein functions through “Darwinian selection.” In vitro compartmentalization (IVC is an in vitro gene screening system for directed evolution of proteins. IVC establishes the link between genetic information (genotype and the protein translated from the information (phenotype, which is essential for all directed evolution methods, by encapsulating both in a nonliving microcompartment. Herein, we introduce a new liposome-based IVC system consisting of a liposome, the protein synthesis using recombinant elements (PURE system and a fluorescence-activated cell sorter (FACS used as a microcompartment, in vitro protein synthesis system, and high-throughput screen, respectively. Liposome-based IVC is characterized by in vitro protein synthesis from a single copy of a gene in a cell-sized unilamellar liposome and quantitative functional evaluation of the synthesized proteins. Examples of liposome-based IVC for screening proteins such as GFP and β-glucuronidase are described. We discuss the future directions for this method and its applications.

Control of gene expression by CRISPR-Cas systems

Science.gov (United States)

2013-01-01

Clustered regularly interspaced short palindromic repeats (CRISPR) loci and their associated cas (CRISPR-associated) genes provide adaptive immunity against viruses (phages) and other mobile genetic elements in bacteria and archaea. While most of the early work has largely been dominated by examples of CRISPR-Cas systems directing the cleavage of phage or plasmid DNA, recent studies have revealed a more complex landscape where CRISPR-Cas loci might be involved in gene regulation. In this review, we summarize the role of these loci in the regulation of gene expression as well as the recent development of synthetic gene regulation using engineered CRISPR-Cas systems. PMID:24273648

Direct interactions of OCA-B and TFII-I regulate immunoglobulin heavy-chain gene transcription by facilitating enhancer-promoter communication.

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Ren, Xiaodi; Siegel, Rachael; Kim, Unkyu; Roeder, Robert G

2011-05-06

B cell-specific coactivator OCA-B, together with Oct-1/2, binds to octamer sites in promoters and enhancers to activate transcription of immunoglobulin (Ig) genes, although the mechanisms underlying their roles in enhancer-promoter communication are unknown. Here, we demonstrate a direct interaction of OCA-B with transcription factor TFII-I, which binds to DICE elements in Igh promoters, that affects transcription at two levels. First, OCA-B relieves HDAC3-mediated Igh promoter repression by competing with HDAC3 for binding to promoter-bound TFII-I. Second, and most importantly, Igh 3' enhancer-bound OCA-B and promoter-bound TFII-I mediate promoter-enhancer interactions, in both cis and trans, that are important for Igh transcription. These and other results reveal an important function for OCA-B in Igh 3' enhancer function in vivo and strongly favor an enhancer mechanism involving looping and facilitated factor recruitment rather than a tracking mechanism. Copyright © 2011 Elsevier Inc. All rights reserved.

The hetC Gene Is a Direct Target of the NtcA Transcriptional Regulator in Cyanobacterial Heterocyst Development

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Muro-Pastor, Alicia M.; Valladares, Ana; Flores, Enrique; Herrero, Antonia

1999-01-01

The heterocyst is the site of nitrogen fixation in aerobically grown cultures of some filamentous cyanobacteria. Heterocyst development in Anabaena sp. strain PCC 7120 is dependent on the global nitrogen regulator NtcA and requires, among others, the products of the hetR and hetC genes. Expression of hetC, tested by RNA- DNA hybridization, was impaired in an ntcA mutant. A nitrogen-regulated, NtcA-dependent putative transcription start point was localized at nucleotide −571 with respect to the hetC translational start. Sequences upstream from this transcription start point exhibit the structure of the canonical cyanobacterial promoter activated by NtcA, and purified NtcA protein specifically bound to a DNA fragment containing this promoter. Activation of expression of hetC during heterocyst development appears thus to be directly operated by NtcA. NtcA-mediated activation of hetR expression was not impaired in a hetC mutant, indicating that HetC is not an NtcA-dependent element required for hetR induction. PMID:10542167

Site-Directed Genome Knockout in Chicken Cell Line and Embryos Can Use CRISPR/Cas Gene Editing Technology

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Qisheng Zuo

2016-06-01

Full Text Available The present study established an efficient genome editing approach for the construction of stable transgenic cell lines of the domestic chicken (Gallus gallus domesticus. Our objectives were to facilitate the breeding of high-yield, high-quality chicken strains, and to investigate gene function in chicken stem cells. Three guide RNA (gRNAs were designed to knockout the C2EIP gene, and knockout efficiency was evaluated in DF-1 chicken fibroblasts and chicken ESCs using the luciferase single-strand annealing (SSA recombination assay, T7 endonuclease I (T7EI assay, and TA clone sequencing. In addition, the polyethylenimine-encapsulated Cas9/gRNA plasmid was injected into fresh fertilized eggs. At 4.5 d later, frozen sections of the embryos were prepared, and knockout efficiency was evaluated by the T7EI assay. SSA assay results showed that luciferase activity of the vector expressing gRNA-3 was double that of the control. Results of the T7EI assay and TA clone sequencing indicated that Cas9/gRNA vector-mediated gene knockdown efficiency was approximately 27% in both DF-1 cells and ESCs. The CRISPR/Cas9 vector was also expressed in chicken embryos, resulting in gene knockdown in three of the 20 embryos (gene knockdown efficiency 15%. Taken together, our results indicate that the CRISPR/Cas9 system can mediate stable gene knockdown at the cell and embryo levels in domestic chickens.

Mesenchymal Stem Cells Induce Epithelial to Mesenchymal Transition in Colon Cancer Cells through Direct Cell-to-Cell Contact

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Hidehiko Takigawa

2017-05-01

Full Text Available We previously reported that in an orthotopic nude mouse model of human colon cancer, bone marrow–derived mesenchymal stem cells (MSCs migrated to the tumor stroma and promoted tumor growth and metastasis. Here, we evaluated the proliferation and migration ability of cancer cells cocultured with MSCs to elucidate the mechanism of interaction between cancer cells and MSCs. Proliferation and migration of cancer cells increased following direct coculture with MSCs but not following indirect coculture. Thus, we hypothesized that direct contact between cancer cells and MSCs was important. We performed a microarray analysis of gene expression in KM12SM colon cancer cells directly cocultured with MSCs. Expression of epithelial-mesenchymal transition (EMT–related genes such as fibronectin (FN, SPARC, and galectin 1 was increased by direct coculture with MSCs. We also confirmed the upregulation of these genes with real-time polymerase chain reaction. Gene expression was not elevated in cancer cells indirectly cocultured with MSCs. Among the EMT-related genes upregulated by direct coculture with MSCs, we examined the immune localization of FN, a well-known EMT marker. In coculture assay in chamber slides, expression of FN was seen only at the edges of cancer clusters where cancer cells directly contacted MSCs. FN expression in cancer cells increased at the tumor periphery and invasive edge in orthotopic nude mouse tumors and human colon cancer tissues. These results suggest that MSCs induce EMT in colon cancer cells via direct cell-to-cell contact and may play an important role in colon cancer metastasis.

Direct conversion of human fibroblasts into functional osteoblasts by defined factors.

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Yamamoto, Kenta; Kishida, Tsunao; Sato, Yoshiki; Nishioka, Keisuke; Ejima, Akika; Fujiwara, Hiroyoshi; Kubo, Toshikazu; Yamamoto, Toshiro; Kanamura, Narisato; Mazda, Osam

2015-05-12

Osteoblasts produce calcified bone matrix and contribute to bone formation and remodeling. In this study, we established a procedure to directly convert human fibroblasts into osteoblasts by transducing some defined factors and culturing in osteogenic medium. Osteoblast-specific transcription factors, Runt-related transcription factor 2 (Runx2), and Osterix, in combination with Octamer-binding transcription factor 3/4 (Oct4) and L-Myc (RXOL) transduction, converted ∼ 80% of the fibroblasts into osteocalcin-producing cells. The directly converted osteoblasts (dOBs) induced by RXOL displayed a similar gene expression profile as normal human osteoblasts and contributed to bone repair after transplantation into immunodeficient mice at artificial bone defect lesions. The dOBs expressed endogenous Runx2 and Osterix, and did not require continuous expression of the exogenous genes to maintain their phenotype. Another combination, Oct4 plus L-Myc (OL), also induced fibroblasts to produce bone matrix, but the OL-transduced cells did not express Osterix and exhibited a more distant gene expression profile to osteoblasts compared with RXOL-transduced cells. These findings strongly suggest successful direct reprogramming of fibroblasts into functional osteoblasts by RXOL, a technology that may provide bone regeneration therapy against bone disorders.

The development of genes associated with radiosensitivity of cervical cancer

International Nuclear Information System (INIS)

Li Hongyan; Chen Zhihua; He Guifang

2007-01-01

It has a good application prospect to predict effects of radiotherapy by examining radiosensitivity of patients with cervical cancers before their radiotherapy. Prediction of tumor cell radiosensitivity according to their level of gene expression and gene therapy to reverse radio-resistance prior to radiation on cervical cancers are heated researches on tumor therapy. The expression of some proliferation-related genes, apoptosis-related genes and hypoxia-related genes can inerease the radiosensitivity of cervical cancer. Microarray technology may have more direct applications to the study of biological pathway contributing to radiation resistance and may lead to development of alternative treatment modalities. (authors)

Targeted integration of genes in Xenopus tropicalis

DEFF Research Database (Denmark)

Shi, Zhaoying; Tian, Dandan; Xin, Huhu

2017-01-01

With the successful establishment of both targeted gene disruption and integration methods in the true diploid frog Xenopus tropicalis, this excellent vertebrate genetic model now is making a unique contribution to modelling human diseases. Here, we summarize our efforts on establishing homologous...... recombination-mediated targeted integration in Xenopus tropicalis, the usefulness, and limitation of targeted integration via the homology-independent strategy, and future directions on how to further improve targeted gene integration in Xenopus tropicalis....

Lipofection of cultured mouse muscle cells: a direct comparison of Lipofectamine and DOSPER.

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Dodds, E; Dunckley, M G; Naujoks, K; Michaelis, U; Dickson, G

1998-04-01

Cationic lipid-DNA complexes (lipoplexes) have been widely used as gene transfer vectors which avoid the adverse immunogenicity and potential for viraemia of viral vectors. With the long-term aim of gene transfer into skeletal muscle in vivo, we describe a direct in vitro comparison of two commercially available cationic lipid formulations, Lipofectamine and DOSPER. Optimisation of transfection was performed in the C2C12 mouse muscle cell line, before further studies in primary mouse myoblasts and C2C12 myotubes. Reporter gene constructs expressing either E. coli beta-galactosidase or green fluorescent protein (GFP) were used in order to evaluate transfection efficiency by histochemical staining or FACS analysis, respectively. Both lipid formulations were able to promote efficient, reproducible gene transfer in C2C12 cells, and to transfect primary mouse myoblast cultures successfully. However, DOSPER exhibited the important advantage of being able to transfect cells in the presence of serum of both bovine and murine origin. This feature allowed increased cell survival during in vitro transfections, and may be advantageous for direct in vivo gene transfer efficacy.

ATAF1 transcription factor directly regulates abscisic acid biosynthetic gene NCED3 in Arabidopsis thaliana

DEFF Research Database (Denmark)

Jensen, Michael Krogh; Lindemose, Søren; De Masi, Federico

2013-01-01

ATAF1, an Arabidopsis thaliana NAC transcription factor, plays important roles in plant adaptation to environmental stress and development. To search for ATAF1 target genes, we used protein binding microarrays and chromatin-immunoprecipitation (ChIP). This identified T[A,C,G]CGT[A,G] and TT[A,C,G...... abscisic acid (ABA) phytohormone biosynthetic gene NCED3. ChIP-qPCR and expression analysis showed that ATAF1 binding to the NCED3 promoter correlated with increased NCED3 expression and ABA hormone levels. These results indicate that ATAF1 regulates ABA biosynthesis....

Prospects for Gene Therapy in the Fragile X Syndrome

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Rattazzi, Mario C.; LaFauci, Giuseppe; Brown, W. Ted

2004-01-01

Gene therapy is unarguably the definitive way to treat, and possibly cure, genetic diseases. A straightforward concept in theory, in practice it has proven difficult to realize, even when directed to easily accessed somatic cell systems. Gene therapy for diseases in which the central nervous system (CNS) is the target organ presents even greater…

Conditions for the Evolution of Gene Clusters in Bacterial Genomes

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Ballouz, Sara; Francis, Andrew R.; Lan, Ruiting; Tanaka, Mark M.

2010-01-01

Genes encoding proteins in a common pathway are often found near each other along bacterial chromosomes. Several explanations have been proposed to account for the evolution of these structures. For instance, natural selection may directly favour gene clusters through a variety of mechanisms, such as increased efficiency of coregulation. An alternative and controversial hypothesis is the selfish operon model, which asserts that clustered arrangements of genes are more easily transferred to other species, thus improving the prospects for survival of the cluster. According to another hypothesis (the persistence model), genes that are in close proximity are less likely to be disrupted by deletions. Here we develop computational models to study the conditions under which gene clusters can evolve and persist. First, we examine the selfish operon model by re-implementing the simulation and running it under a wide range of conditions. Second, we introduce and study a Moran process in which there is natural selection for gene clustering and rearrangement occurs by genome inversion events. Finally, we develop and study a model that includes selection and inversion, which tracks the occurrence and fixation of rearrangements. Surprisingly, gene clusters fail to evolve under a wide range of conditions. Factors that promote the evolution of gene clusters include a low number of genes in the pathway, a high population size, and in the case of the selfish operon model, a high horizontal transfer rate. The computational analysis here has shown that the evolution of gene clusters can occur under both direct and indirect selection as long as certain conditions hold. Under these conditions the selfish operon model is still viable as an explanation for the evolution of gene clusters. PMID:20168992

Detection of EPO gene doping in blood.

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Neuberger, Elmo W I; Jurkiewicz, Magdalena; Moser, Dirk A; Simon, Perikles

2012-11-01

Gene doping--or the abuse of gene therapy--will continue to threaten the sports world. History has shown that progress in medical research is likely to be abused in order to enhance human performance. In this review, we critically discuss the progress and the risks associated with the field of erythropoietin (EPO) gene therapy and its applicability to EPO gene doping. We present typical vector systems that are employed in ex vivo and in vivo gene therapy trials. Due to associated risks, gene doping is not a feasible alternative to conventional EPO or blood doping at this time. Nevertheless, it is well described that about half of the elite athlete population is in principle willing to risk its health to gain a competitive advantage. This includes the use of technologies that lack safety approval. Sophisticated detection approaches are a prerequisite for prevention of unapproved and uncontrolled use of gene therapy technology. In this review, we present current detection approaches for EPO gene doping, with a focus on blood-based direct and indirect approaches. Gene doping is detectable in principle, and recent DNA-based detection strategies enable long-term detection of transgenic DNA (tDNA) following in vivo gene transfer. Copyright © 2012 John Wiley & Sons, Ltd.

Determination of transcriptional units and gene products from the ftsA region of Escherichia coli.

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Lutkenhaus, J F; Wu, H C

1980-01-01

Lambda transducing phage gamma 16-2 carries the genes envA, ftsZ, ftsA, ddl, and murC and directs the synthesis of six unique proteins in ultraviolet-irradiated cells. Various derivatives of gamma 16-2 carrying smaller segments of the bacterial deoxyribonucleic acid have also been analyzed for their capacity to direct protein synthesis in ultraviolet-irradiated cells. These results, in combination with genetic results, have allowed the gene product of each of these genes to be assigned. In addition, an unidentified gene was located counterclockwise to murC between murC and murF. Analysis of the direction of transcription indicates that murC, ddl, ftsA, and ftsZ are transcribed clockwise on the Escherichia coli genetic map, and envA is transcribed counterclockwise. In addition, it is shown that each of the genes envA, ftsZ, and ftsA can be expressed independently. Images PMID:6447690

Decoding gene patents in Australia.

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Denley, Adam; Cherry, James

2014-10-03

Patents directed to naturally occurring genetic material, such as DNA, RNA, chromosomes, and genes, in an isolated or purified form have been granted in Australia for many years. This review provides scientists with a summary of the gene patent debate from an Australian perspective and specifically reviews how the various levels of the legal system as they apply to patents-the Australian Patent Office, Australian courts, and Australian government-have dealt with the issue of whether genetic material is proper subject matter for a patent. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

GeneAnalytics: An Integrative Gene Set Analysis Tool for Next Generation Sequencing, RNAseq and Microarray Data.

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Ben-Ari Fuchs, Shani; Lieder, Iris; Stelzer, Gil; Mazor, Yaron; Buzhor, Ella; Kaplan, Sergey; Bogoch, Yoel; Plaschkes, Inbar; Shitrit, Alina; Rappaport, Noa; Kohn, Asher; Edgar, Ron; Shenhav, Liraz; Safran, Marilyn; Lancet, Doron; Guan-Golan, Yaron; Warshawsky, David; Shtrichman, Ronit

2016-03-01

Postgenomics data are produced in large volumes by life sciences and clinical applications of novel omics diagnostics and therapeutics for precision medicine. To move from "data-to-knowledge-to-innovation," a crucial missing step in the current era is, however, our limited understanding of biological and clinical contexts associated with data. Prominent among the emerging remedies to this challenge are the gene set enrichment tools. This study reports on GeneAnalytics™ ( geneanalytics.genecards.org ), a comprehensive and easy-to-apply gene set analysis tool for rapid contextualization of expression patterns and functional signatures embedded in the postgenomics Big Data domains, such as Next Generation Sequencing (NGS), RNAseq, and microarray experiments. GeneAnalytics' differentiating features include in-depth evidence-based scoring algorithms, an intuitive user interface and proprietary unified data. GeneAnalytics employs the LifeMap Science's GeneCards suite, including the GeneCards®--the human gene database; the MalaCards-the human diseases database; and the PathCards--the biological pathways database. Expression-based analysis in GeneAnalytics relies on the LifeMap Discovery®--the embryonic development and stem cells database, which includes manually curated expression data for normal and diseased tissues, enabling advanced matching algorithm for gene-tissue association. This assists in evaluating differentiation protocols and discovering biomarkers for tissues and cells. Results are directly linked to gene, disease, or cell "cards" in the GeneCards suite. Future developments aim to enhance the GeneAnalytics algorithm as well as visualizations, employing varied graphical display items. Such attributes make GeneAnalytics a broadly applicable postgenomics data analyses and interpretation tool for translation of data to knowledge-based innovation in various Big Data fields such as precision medicine, ecogenomics, nutrigenomics, pharmacogenomics, vaccinomics

pGenN, a Gene Normalization Tool for Plant Genes and Proteins in Scientific Literature

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Ding, Ruoyao; Arighi, Cecilia N.; Lee, Jung-Youn; Wu, Cathy H.; Vijay-Shanker, K.

2015-01-01

Background Automatically detecting gene/protein names in the literature and connecting them to databases records, also known as gene normalization, provides a means to structure the information buried in free-text literature. Gene normalization is critical for improving the coverage of annotation in the databases, and is an essential component of many text mining systems and database curation pipelines. Methods In this manuscript, we describe a gene normalization system specifically tailored for plant species, called pGenN (pivot-based Gene Normalization). The system consists of three steps: dictionary-based gene mention detection, species assignment, and intra species normalization. We have developed new heuristics to improve each of these phases. Results We evaluated the performance of pGenN on an in-house expertly annotated corpus consisting of 104 plant relevant abstracts. Our system achieved an F-value of 88.9% (Precision 90.9% and Recall 87.2%) on this corpus, outperforming state-of-art systems presented in BioCreative III. We have processed over 440,000 plant-related Medline abstracts using pGenN. The gene normalization results are stored in a local database for direct query from the pGenN web interface (proteininformationresource.org/pgenn/). The annotated literature corpus is also publicly available through the PIR text mining portal (proteininformationresource.org/iprolink/). PMID:26258475

Rooting gene trees without outgroups: EP rooting.

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Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

2012-01-01

Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

Progresses towards safe and efficient gene therapy vectors.

Science.gov (United States)

Chira, Sergiu; Jackson, Carlo S; Oprea, Iulian; Ozturk, Ferhat; Pepper, Michael S; Diaconu, Iulia; Braicu, Cornelia; Raduly, Lajos-Zsolt; Calin, George A; Berindan-Neagoe, Ioana

2015-10-13

The emergence of genetic engineering at the beginning of the 1970's opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors.

The relationship between codon usage bias and cold resistant genes

International Nuclear Information System (INIS)

Barozai, M.Y.; Din, M.

2014-01-01

This research is based on synonymous codon usage which has been well-known as a feature that affects typical expression level of protein in an organism. Different organisms prefer different codons for same amino acid and this is called Codon Usage Bias (CUB). The codon usage directly affects the level or even direction of changes in protein expression in responses to environmental stimuli. Cold stress is a major abiotic factor that limits the agricultural productivity of plants. In the recent study CUB has been studied in Arabidopsis thaliana cold resistant and housekeeping genes and their homologs in rice (Oryza sativa) to understand the cold stress and housekeeping genes relation with CUB. Six cold resistant and three housekeeping genes in Arabidopsis thaliana and their homologs in rice, were subjected to CUB analysis. The three cold resistant genes (DREB1B, RCI and MYB15) showed more than 50% (52%, 61% and 66% respectively) similar codon usage bias for Arabidopsis thaliana and rice. On the other hand three cold resistant genes (MPK3, ICE1 and ZAT12) showed less than 50% (38%, 38% and 47% respectively) similar codon usage bias for Arabidopsis thaliana and rice. The three housekeeping genes (Actin, Tubulin and Ubiquitin) showed 76% similar codon usage bias for Arabidopsis thaliana and rice. This study will help to manage the plant gene expression through codon optimization under the cold stress. (author)

A multiplex branched DNA assay for parallel quantitative gene expression profiling.

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Flagella, Michael; Bui, Son; Zheng, Zhi; Nguyen, Cung Tuong; Zhang, Aiguo; Pastor, Larry; Ma, Yunqing; Yang, Wen; Crawford, Kimberly L; McMaster, Gary K; Witney, Frank; Luo, Yuling

2006-05-01

We describe a novel method to quantitatively measure messenger RNA (mRNA) expression of multiple genes directly from crude cell lysates and tissue homogenates without the need for RNA purification or target amplification. The multiplex branched DNA (bDNA) assay adapts the bDNA technology to the Luminex fluorescent bead-based platform through the use of cooperative hybridization, which ensures an exceptionally high degree of assay specificity. Using in vitro transcribed RNA as reference standards, we demonstrated that the assay is highly specific, with cross-reactivity less than 0.2%. We also determined that the assay detection sensitivity is 25,000 RNA transcripts with intra- and interplate coefficients of variance of less than 10% and less than 15%, respectively. Using three 10-gene panels designed to measure proinflammatory and apoptosis responses, we demonstrated sensitive and specific multiplex gene expression profiling directly from cell lysates. The gene expression change data demonstrate a high correlation coefficient (R(2)=0.94) compared with measurements obtained using the single-plex bDNA assay. Thus, the multiplex bDNA assay provides a powerful means to quantify the gene expression profile of a defined set of target genes in large sample populations.

A genome-wide scan for signatures of directional selection in domesticated pigs.

Science.gov (United States)

Moon, Sunjin; Kim, Tae-Hun; Lee, Kyung-Tai; Kwak, Woori; Lee, Taeheon; Lee, Si-Woo; Kim, Myung-Jick; Cho, Kyuho; Kim, Namshin; Chung, Won-Hyong; Sung, Samsun; Park, Taesung; Cho, Seoae; Groenen, Martien Am; Nielsen, Rasmus; Kim, Yuseob; Kim, Heebal

2015-02-25

Animal domestication involved drastic phenotypic changes driven by strong artificial selection and also resulted in new populations of breeds, established by humans. This study aims to identify genes that show evidence of recent artificial selection during pig domestication. Whole-genome resequencing of 30 individual pigs from domesticated breeds, Landrace and Yorkshire, and 10 Asian wild boars at ~16-fold coverage was performed resulting in over 4.3 million SNPs for 19,990 genes. We constructed a comprehensive genome map of directional selection by detecting selective sweeps using an F ST-based approach that detects directional selection in lineages leading to the domesticated breeds and using a haplotype-based test that detects ongoing selective sweeps within the breeds. We show that candidate genes under selection are significantly enriched for loci implicated in quantitative traits important to pig reproduction and production. The candidate gene with the strongest signals of directional selection belongs to group III of the metabolomics glutamate receptors, known to affect brain functions associated with eating behavior, suggesting that loci under strong selection include loci involved in behaviorial traits in domesticated pigs including tameness. We show that a significant proportion of selection signatures coincide with loci that were previously inferred to affect phenotypic variation in pigs. We further identify functional enrichment related to behavior, such as signal transduction and neuronal activities, for those targets of selection during domestication in pigs.

In Vivo Gene Therapy of Hemophilia B: Sustained Partial Correction in Factor IX-Deficient Dogs

Science.gov (United States)

Kay, Mark A.; Rothenberg, Steven; Landen, Charles N.; Bellinger, Dwight A.; Leland, Frances; Toman, Carol; Finegold, Milton; Thompson, Arthur R.; Read, M. S.; Brinkhous, Kenneth M.; Woo, Savio L. C.

1993-10-01

The liver represents a model organ for gene therapy. A method has been developed for hepatic gene transfer in vivo by the direct infusion of recombinant retroviral vectors into the portal vasculature, which results in the persistent expression of exogenous genes. To determine if these technologies are applicable for the treatment of hemophilia B patients, preclinical efficacy studies were done in a hemophilia B dog model. When the canine factor IX complementary DNA was transduced directly into the hepatocytes of affected dogs in vivo, the animals constitutively expressed low levels of canine factor IX for more than 5 months. Persistent expression of the clotting. factor resulted in reductions of whole blood clotting and partial thromboplastin times of the treated animals. Thus, long-term treatment of hemophilia B patients may be feasible by direct hepatic gene therapy in vivo.

The completion of the Mammalian Gene Collection (MGC)

Science.gov (United States)

Temple, Gary; Gerhard, Daniela S.; Rasooly, Rebekah; Feingold, Elise A.; Good, Peter J.; Robinson, Cristen; Mandich, Allison; Derge, Jeffrey G.; Lewis, Jeanne; Shoaf, Debonny; Collins, Francis S.; Jang, Wonhee; Wagner, Lukas; Shenmen, Carolyn M.; Misquitta, Leonie; Schaefer, Carl F.; Buetow, Kenneth H.; Bonner, Tom I.; Yankie, Linda; Ward, Ming; Phan, Lon; Astashyn, Alex; Brown, Garth; Farrell, Catherine; Hart, Jennifer; Landrum, Melissa; Maidak, Bonnie L.; Murphy, Michael; Murphy, Terence; Rajput, Bhanu; Riddick, Lillian; Webb, David; Weber, Janet; Wu, Wendy; Pruitt, Kim D.; Maglott, Donna; Siepel, Adam; Brejova, Brona; Diekhans, Mark; Harte, Rachel; Baertsch, Robert; Kent, Jim; Haussler, David; Brent, Michael; Langton, Laura; Comstock, Charles L.G.; Stevens, Michael; Wei, Chaochun; van Baren, Marijke J.; Salehi-Ashtiani, Kourosh; Murray, Ryan R.; Ghamsari, Lila; Mello, Elizabeth; Lin, Chenwei; Pennacchio, Christa; Schreiber, Kirsten; Shapiro, Nicole; Marsh, Amber; Pardes, Elizabeth; Moore, Troy; Lebeau, Anita; Muratet, Mike; Simmons, Blake; Kloske, David; Sieja, Stephanie; Hudson, James; Sethupathy, Praveen; Brownstein, Michael; Bhat, Narayan; Lazar, Joseph; Jacob, Howard; Gruber, Chris E.; Smith, Mark R.; McPherson, John; Garcia, Angela M.; Gunaratne, Preethi H.; Wu, Jiaqian; Muzny, Donna; Gibbs, Richard A.; Young, Alice C.; Bouffard, Gerard G.; Blakesley, Robert W.; Mullikin, Jim; Green, Eric D.; Dickson, Mark C.; Rodriguez, Alex C.; Grimwood, Jane; Schmutz, Jeremy; Myers, Richard M.; Hirst, Martin; Zeng, Thomas; Tse, Kane; Moksa, Michelle; Deng, Merinda; Ma, Kevin; Mah, Diana; Pang, Johnson; Taylor, Greg; Chuah, Eric; Deng, Athena; Fichter, Keith; Go, Anne; Lee, Stephanie; Wang, Jing; Griffith, Malachi; Morin, Ryan; Moore, Richard A.; Mayo, Michael; Munro, Sarah; Wagner, Susan; Jones, Steven J.M.; Holt, Robert A.; Marra, Marco A.; Lu, Sun; Yang, Shuwei; Hartigan, James; Graf, Marcus; Wagner, Ralf; Letovksy, Stanley; Pulido, Jacqueline C.; Robison, Keith; Esposito, Dominic; Hartley, James; Wall, Vanessa E.; Hopkins, Ralph F.; Ohara, Osamu; Wiemann, Stefan

2009-01-01

Since its start, the Mammalian Gene Collection (MGC) has sought to provide at least one full-protein-coding sequence cDNA clone for every human and mouse gene with a RefSeq transcript, and at least 6200 rat genes. The MGC cloning effort initially relied on random expressed sequence tag screening of cDNA libraries. Here, we summarize our recent progress using directed RT-PCR cloning and DNA synthesis. The MGC now contains clones with the entire protein-coding sequence for 92% of human and 89% of mouse genes with curated RefSeq (NM-accession) transcripts, and for 97% of human and 96% of mouse genes with curated RefSeq transcripts that have one or more PubMed publications, in addition to clones for more than 6300 rat genes. These high-quality MGC clones and their sequences are accessible without restriction to researchers worldwide. PMID:19767417

Hydroxymethylation at Gene Regulatory Regions Directs Stem/Early Progenitor Cell Commitment during Erythropoiesis

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Jozef Madzo

2014-01-01

Full Text Available Hematopoietic stem cell differentiation involves the silencing of self-renewal genes and induction of a specific transcriptional program. Identification of multiple covalent cytosine modifications raises the question of how these derivatized bases influence stem cell commitment. Using a replicative primary human hematopoietic stem/progenitor cell differentiation system, we demonstrate dynamic changes of 5-hydroxymethylcytosine (5-hmC during stem cell commitment and differentiation to the erythroid lineage. Genomic loci that maintain or gain 5-hmC density throughout erythroid differentiation contain binding sites for erythroid transcription factors and several factors not previously recognized as erythroid-specific factors. The functional importance of 5-hmC was demonstrated by impaired erythroid differentiation, with augmentation of myeloid potential, and disrupted 5-hmC patterning in leukemia patient-derived CD34+ stem/early progenitor cells with TET methylcytosine dioxygenase 2 (TET2 mutations. Thus, chemical conjugation and affinity purification of 5-hmC-enriched sequences followed by sequencing serve as resources for deciphering functional implications for gene expression during stem cell commitment and differentiation along a particular lineage.

Conditions for the evolution of gene clusters in bacterial genomes.

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Sara Ballouz

2010-02-01

Full Text Available Genes encoding proteins in a common pathway are often found near each other along bacterial chromosomes. Several explanations have been proposed to account for the evolution of these structures. For instance, natural selection may directly favour gene clusters through a variety of mechanisms, such as increased efficiency of coregulation. An alternative and controversial hypothesis is the selfish operon model, which asserts that clustered arrangements of genes are more easily transferred to other species, thus improving the prospects for survival of the cluster. According to another hypothesis (the persistence model, genes that are in close proximity are less likely to be disrupted by deletions. Here we develop computational models to study the conditions under which gene clusters can evolve and persist. First, we examine the selfish operon model by re-implementing the simulation and running it under a wide range of conditions. Second, we introduce and study a Moran process in which there is natural selection for gene clustering and rearrangement occurs by genome inversion events. Finally, we develop and study a model that includes selection and inversion, which tracks the occurrence and fixation of rearrangements. Surprisingly, gene clusters fail to evolve under a wide range of conditions. Factors that promote the evolution of gene clusters include a low number of genes in the pathway, a high population size, and in the case of the selfish operon model, a high horizontal transfer rate. The computational analysis here has shown that the evolution of gene clusters can occur under both direct and indirect selection as long as certain conditions hold. Under these conditions the selfish operon model is still viable as an explanation for the evolution of gene clusters.

Rhabdovirus accessory genes.

Science.gov (United States)

Walker, Peter J; Dietzgen, Ralf G; Joubert, D Albert; Blasdell, Kim R

2011-12-01

The Rhabdoviridae is one of the most ecologically diverse families of RNA viruses with members infecting a wide range of organisms including placental mammals, marsupials, birds, reptiles, fish, insects and plants. The availability of complete nucleotide sequences for an increasing number of rhabdoviruses has revealed that their ecological diversity is reflected in the diversity and complexity of their genomes. The five canonical rhabdovirus structural protein genes (N, P, M, G and L) that are shared by all rhabdoviruses are overprinted, overlapped and interspersed with a multitude of novel and diverse accessory genes. Although not essential for replication in cell culture, several of these genes have been shown to have roles associated with pathogenesis and apoptosis in animals, and cell-to-cell movement in plants. Others appear to be secreted or have the characteristics of membrane-anchored glycoproteins or viroporins. However, most encode proteins of unknown function that are unrelated to any other known proteins. Understanding the roles of these accessory genes and the strategies by which rhabdoviruses use them to engage, divert and re-direct cellular processes will not only present opportunities to develop new anti-viral therapies but may also reveal aspects of cellar function that have broader significance in biology, agriculture and medicine. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Vorinostat in combination with bortezomib in patients with advanced malignancies directly alters transcription of target genes.

Science.gov (United States)

Kolesar, Jill M; Traynor, Anne M; Holen, Kyle D; Hoang, Tien; Seo, Songwon; Kim, Kyungmann; Alberti, Dona; Espinoza-Delgado, Igor; Wright, John J; Wilding, George; Bailey, Howard H; Schelman, William R

2013-09-01

Vorinostat is a small molecule inhibitor of class I and II histone deacetylase enzymes which alters the expression of target genes including the cell cycle gene p21, leading to cell cycle arrest and apoptosis. Patients enrolled in a phase I trial were treated with vorinostat alone on day 1 and vorinostat and bortezomib in combination on day 9. Paired biopsies were obtained in eleven subjects. Blood samples were obtained on days 1 and 9 of cycle 1 prior to dosing and 2 and 6 h post-dosing in all 60 subjects. Gene expression of p21, HSP70, AKT, Nur77, ERB1, and ERB2 was evaluated in peripheral blood mononuclear cells and tissue samples. Chromatin immunoprecipitation of p21, HSP70, and Nur77 was also performed in biopsy samples. In peripheral blood mononuclear cells, Nur77 was significantly and consistently decreased 2 h after vorinostat administration on both days 1 and 9, median ratio of gene expression relative to baseline of 0.69 with interquartile range 0.49-1.04 (p vorinostat and bortezomib. p21, a downstream target of Nur77, was significantly decreased on day 9, 2 and 6 h after administration of vorinostat and bortezomib, 0.67 (0.41-1.03) (p vorinostat in tissue biopsies in most patients. Vorinostat inhibits Nur77 expression, which in turn may decrease p21 and AKT expression in PBMCs. The influence of vorinostat on target gene expression in tumor tissue was variable; however, most patients demonstrated interaction of acetylated H3 with Nur77, HSP70, and p21 which provides evidence of interaction with the transcriptionally active acetylated H3.

Direct trans-activation of the human cyclin D2 gene by the oncogene product Tax of human T-cell leukemia virus type I.

Science.gov (United States)

Huang, Y; Ohtani, K; Iwanaga, R; Matsumura, Y; Nakamura, M

2001-03-01

Cyclins are one of the pivotal determinants regulating cell cycle progression. We previously reported that the trans-activator Tax of human T-cell leukemia virus type I (HTLV-I) induces endogenous cyclin D2 expression along with cell cycle progression in a resting human T-cell line, Kit 225, suggesting a role of cyclin D2 in Tax-mediated cell cycle progression. The cyclin D2 gene has a typical E2F binding element, raising the possibility that induction of cyclin D2 expression is a consequence of cell cycle progression. In this study, we examined the role and molecular mechanism of induction of the endogenous human cyclin D2 gene by Tax. Introduction of p19(INK4d), a cyclin dependent kinase (CDK) inhibitor of the INK4 family specific for D-type CDK, inhibited Tax-mediated activation of E2F, indicating requirement of D-type CDK in Tax-mediated activation of E2F. Previously indicated E2F binding element and two NF-kappaB-like binding elements in the 1.6 kbp cyclin D2 promoter fragment had little, if any, effect on responsiveness to Tax. We found that trans-activation of the cyclin D2 promoter by Tax was mainly mediated by a newly identified NF-kappaB-like element with auxiliary contribution of a CRE-like element residing in sequences downstream of -444 which were by themselves sufficient for trans-activation by Tax. These results indicate that Tax directly trans-activates the cyclin D2 gene, resulting in growth promotion and perhaps leukemogenesis through activation of D-type CDK.

Positive-negative-selection-mediated gene targeting in rice

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Zenpei eShimatani

2015-01-01

Full Text Available Gene targeting (GT refers to the designed modification of genomic sequence(s through homologous recombination (HR. GT is a powerful tool both for the study of gene function and for molecular breeding. However, in transformation of higher plants, non-homologous end joining (NHEJ occurs overwhelmingly in somatic cells, masking HR-mediated GT. Positive-negative selection (PNS is an approach for finding HR-mediated GT events because it can eliminate NHEJ effectively by expression of a negative-selection marker gene. In rice—a major crop worldwide—reproducible PNS-mediated GT of endogenous genes has now been successfully achieved. The procedure is based on strong PNS using diphtheria toxin A-fragment as a negative marker, and has succeeded in the directed modification of several endogenous rice genes in various ways. In addition to gene knock-outs and knock-ins, a nucleotide substitution in a target gene was also achieved recently. This review presents a summary of the development of the rice PNS system, highlighting its advantages. Different types of gene modification and gene editing aimed at developing new plant breeding technology (NPBT based on PNS are discussed.

Apparent directional selection by biased pleiotropic mutation.

Science.gov (United States)

Tanaka, Yoshinari

2010-07-01

Pleiotropic effects of deleterious mutations are considered to be among the factors responsible for genetic constraints on evolution by long-term directional selection acting on a quantitative trait. If pleiotropic phenotypic effects are biased in a particular direction, mutations generate apparent directional selection, which refers to the covariance between fitness and the trait owing to a linear association between the number of mutations possessed by individuals and the genotypic values of the trait. The present analysis has shown how the equilibrium mean value of the trait is determined by a balance between directional selection and biased pleiotropic mutations. Assuming that genes act additively both on the trait and on fitness, the total variance-standardized directional selection gradient was decomposed into apparent and true components. Experimental data on mutation bias from the bristle traits of Drosophila and life history traits of Daphnia suggest that apparent selection explains a small but significant fraction of directional selection pressure that is observed in nature; the data suggest that changes induced in a trait by biased pleiotropic mutation (i.e., by apparent directional selection) are easily compensated for by (true) directional selection.

A xylanase gene directly cloned from the genomic DNA of alkaline wastewater sludge showing application potential in the paper industry.

Science.gov (United States)

Zhao, Yanyu; Luo, Huiying; Meng, Kun; Shi, Pengjun; Wang, Guozeng; Yang, Peilong; Yuan, Tiezheng; Yao, Bin

2011-09-01

A xylanase gene, aws-2x, was directly cloned from the genomic DNA of the alkaline wastewater sludge using degenerated PCR and modified TAIL-PCR. The deduced amino acid sequence of AWS-2x shared the highest identity (60%) with the xylanase from Chryseobacterium gleum belonging to the glycosyl hydrolase GH family 10. Recombinant AWS-2x was expressed in Escherichia coli BL21 (DE3) and purified to electrophoretic homogeneity. The enzyme showed maximal activity at pH 7.5 and 55 °C, maintained more than 50% of maximal activity when assayed at pH 9.0, and was stable over a wide pH range from 4.0 to 11.0. The specific activity of AWS-2x towards hardwood xylan (beechwood and birchwood xylan) was significantly higher than that to cereal xylan (oat spelt xylan and wheat arabinoxylan). These properties make AWS-2x a potential candidate for application in the pulp and paper industry.

A quantitative and direct PCR assay for the subspecies-specific detection of Clavibacter michiganensis subsp. michiganensis based on a ferredoxin reductase gene.

Science.gov (United States)

Cho, Min Seok; Lee, Jang Ha; Her, Nam Han; Kim, Changkug; Seol, Young-Joo; Hahn, Jang Ho; Baeg, Ji Hyoun; Kim, Hong Gi; Park, Dong Suk

2012-06-01

The Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis is the causal agent of canker disease in tomato. Because it is very important to control newly introduced inoculum sources from commercial materials, the specific detection of this pathogen in seeds and seedlings is essential for effective disease control. In this study, a novel and efficient assay for the detection and quantitation of C. michiganensis subsp. michiganensis in symptomless tomato and red pepper seeds was developed. A pair of polymerase chain reaction (PCR) primers (Cmm141F/R) was designed to amplify a specific 141 bp fragment on the basis of a ferredoxin reductase gene of C. michiganensis subsp. michiganensis NCPPB 382. The specificity of the primer set was evaluated using purified DNA from 16 isolates of five C. michiganensis subspecies, one other Clavibacter species, and 17 other reference bacteria. The primer set amplified a single band of expected size from the genomic DNA obtained from the C. michiganensis subsp. michiganensis strains but not from the other C. michiganensis subspecies or from other Clavibacter species. The detection limit was a single cloned copy of the ferredoxin reductase gene of C. michiganensis subsp. michiganensis. In conclusion, this quantitative direct PCR assay can be applied as a practical diagnostic method for epidemiological research and the sanitary management of seeds and seedlings with a low level or latent infection of C. michiganensis subsp. michiganensis.

Inferring gene dependency network specific to phenotypic alteration based on gene expression data and clinical information of breast cancer.

Science.gov (United States)

Zhou, Xionghui; Liu, Juan

2014-01-01

Although many methods have been proposed to reconstruct gene regulatory network, most of them, when applied in the sample-based data, can not reveal the gene regulatory relations underlying the phenotypic change (e.g. normal versus cancer). In this paper, we adopt phenotype as a variable when constructing the gene regulatory network, while former researches either neglected it or only used it to select the differentially expressed genes as the inputs to construct the gene regulatory network. To be specific, we integrate phenotype information with gene expression data to identify the gene dependency pairs by using the method of conditional mutual information. A gene dependency pair (A,B) means that the influence of gene A on the phenotype depends on gene B. All identified gene dependency pairs constitute a directed network underlying the phenotype, namely gene dependency network. By this way, we have constructed gene dependency network of breast cancer from gene expression data along with two different phenotype states (metastasis and non-metastasis). Moreover, we have found the network scale free, indicating that its hub genes with high out-degrees may play critical roles in the network. After functional investigation, these hub genes are found to be biologically significant and specially related to breast cancer, which suggests that our gene dependency network is meaningful. The validity has also been justified by literature investigation. From the network, we have selected 43 discriminative hubs as signature to build the classification model for distinguishing the distant metastasis risks of breast cancer patients, and the result outperforms those classification models with published signatures. In conclusion, we have proposed a promising way to construct the gene regulatory network by using sample-based data, which has been shown to be effective and accurate in uncovering the hidden mechanism of the biological process and identifying the gene signature for

Synonymous genes explore different evolutionary landscapes.

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Guillaume Cambray

2008-11-01

Full Text Available The evolutionary potential of a gene is constrained not only by the amino acid sequence of its product, but by its DNA sequence as well. The topology of the genetic code is such that half of the amino acids exhibit synonymous codons that can reach different subsets of amino acids from each other through single mutation. Thus, synonymous DNA sequences should access different regions of the protein sequence space through a limited number of mutations, and this may deeply influence the evolution of natural proteins. Here, we demonstrate that this feature can be of value for manipulating protein evolvability. We designed an algorithm that, starting from an input gene, constructs a synonymous sequence that systematically includes the codons with the most different evolutionary perspectives; i.e., codons that maximize accessibility to amino acids previously unreachable from the template by point mutation. A synonymous version of a bacterial antibiotic resistance gene was computed and synthesized. When concurrently submitted to identical directed evolution protocols, both the wild type and the recoded sequence led to the isolation of specific, advantageous phenotypic variants. Simulations based on a mutation isolated only from the synthetic gene libraries were conducted to assess the impact of sub-functional selective constraints, such as codon usage, on natural adaptation. Our data demonstrate that rational design of synonymous synthetic genes stands as an affordable improvement to any directed evolution protocol. We show that using two synonymous DNA sequences improves the overall yield of the procedure by increasing the diversity of mutants generated. These results provide conclusive evidence that synonymous coding sequences do experience different areas of the corresponding protein adaptive landscape, and that a sequence's codon usage effectively constrains the evolution of the encoded protein.

Conditional expression of the vesicular stomatitis virus glycoprotein gene in Escherichia coli.

OpenAIRE

Rose, J K; Shafferman, A

1981-01-01

Bacterial plasmids that directed expression of the vesicular stomatitis virus glycoprotein (G-protein) gene under control of the tryptophan operon regulatory region were constructed. A plasmid directing the synthesis of a G-protein-like protein (containing the NH2-terminal segment of seven amino acids encoded by the trpE gene fused to the complete G-protein sequence lacking only its NH2-terminal methionine) could be transformed into trpR+ (repressed) but not into trpR- (derepressed) cells. Th...

Gene Co-expression Analysis to Characterize Genes Related to Marbling Trait in Hanwoo (Korean) Cattle.

Science.gov (United States)

Lim, Dajeong; Lee, Seung-Hwan; Kim, Nam-Kuk; Cho, Yong-Min; Chai, Han-Ha; Seong, Hwan-Hoo; Kim, Heebal

2013-01-01

Marbling (intramuscular fat) is an important trait that affects meat quality and is a casual factor determining the price of beef in the Korean beef market. It is a complex trait and has many biological pathways related to muscle and fat. There is a need to identify functional modules or genes related to marbling traits and investigate their relationships through a weighted gene co-expression network analysis based on the system level. Therefore, we investigated the co-expression relationships of genes related to the 'marbling score' trait and systemically analyzed the network topology in Hanwoo (Korean cattle). As a result, we determined 3 modules (gene groups) that showed statistically significant results for marbling score. In particular, one module (denoted as red) has a statistically significant result for marbling score (p = 0.008) and intramuscular fat (p = 0.02) and water capacity (p = 0.006). From functional enrichment and relationship analysis of the red module, the pathway hub genes (IL6, CHRNE, RB1, INHBA and NPPA) have a direct interaction relationship and share the biological functions related to fat or muscle, such as adipogenesis or muscle growth. This is the first gene network study with m.logissimus in Hanwoo to observe co-expression patterns in divergent marbling phenotypes. It may provide insights into the functional mechanisms of the marbling trait.

Gene Co-expression Analysis to Characterize Genes Related to Marbling Trait in Hanwoo (Korean Cattle

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Dajeong Lim

2013-01-01

Full Text Available Marbling (intramuscular fat is an important trait that affects meat quality and is a casual factor determining the price of beef in the Korean beef market. It is a complex trait and has many biological pathways related to muscle and fat. There is a need to identify functional modules or genes related to marbling traits and investigate their relationships through a weighted gene co-expression network analysis based on the system level. Therefore, we investigated the co-expression relationships of genes related to the ‘marbling score’ trait and systemically analyzed the network topology in Hanwoo (Korean cattle. As a result, we determined 3 modules (gene groups that showed statistically significant results for marbling score. In particular, one module (denoted as red has a statistically significant result for marbling score (p = 0.008 and intramuscular fat (p = 0.02 and water capacity (p = 0.006. From functional enrichment and relationship analysis of the red module, the pathway hub genes (IL6, CHRNE, RB1, INHBA and NPPA have a direct interaction relationship and share the biological functions related to fat or muscle, such as adipogenesis or muscle growth. This is the first gene network study with m.logissimus in Hanwoo to observe co-expression patterns in divergent marbling phenotypes. It may provide insights into the functional mechanisms of the marbling trait.

Pipette tip with integrated electrodes for gene electrotransfer of cells in suspension: a feasibility study in CHO cells

International Nuclear Information System (INIS)

Rebersek, Matej; Kanduser, Masa; Miklavcic, Damijan

2011-01-01

Gene electrotransfer is a non-viral gene delivery method that requires successful electroporation for DNA delivery into the cells. Changing the direction of the electric field during the pulse application improves the efficacy of gene delivery. In our study, we tested a pipette tip with integrated electrodes that enables changing the direction of the electric field for electroporation of cell suspension for gene electrotransfer. A new pipette tip consists of four cylindrical rod electrodes that allow the application of electric pulses in different electric field directions. The experiments were performed on cell suspension of CHO cells in phosphate buffer. Plasmid DNA encoding for green fluorescent protein (GFP) was used and the efficiency of gene electrotransfer was determined by counting cells expressing GFP 24 h after the experiment. Experimental results showed that the percentage of cells expressing GFP increased when the electric field orientation was changed during the application. The GFP expression was almost two times higher when the pulses were applied in orthogonal directions in comparison with single direction, while cell viability was not significantly affected. We can conclude that results obtained with the described pipette tip are comparable to previously published results on gene electrotransfer using similar electrode geometry and electric pulse parameters. The tested pipette tip, however, allows work with small volumes/samples and requires less cell manipulation

Small RNA-directed epigenetic natural variation in Arabidopsis thaliana.

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Jixian Zhai

2008-04-01

Full Text Available Progress in epigenetics has revealed mechanisms that can heritably regulate gene function independent of genetic alterations. Nevertheless, little is known about the role of epigenetics in evolution. This is due in part to scant data on epigenetic variation among natural populations. In plants, small interfering RNA (siRNA is involved in both the initiation and maintenance of gene silencing by directing DNA methylation and/or histone methylation. Here, we report that, in the model plant Arabidopsis thaliana, a cluster of approximately 24 nt siRNAs found at high levels in the ecotype Landsberg erecta (Ler could direct DNA methylation and heterochromatinization at a hAT element adjacent to the promoter of FLOWERING LOCUS C (FLC, a major repressor of flowering, whereas the same hAT element in ecotype Columbia (Col with almost identical DNA sequence, generates a set of low abundance siRNAs that do not direct these activities. We have called this hAT element MPF for Methylated region near Promoter of FLC, although de novo methylation triggered by an inverted repeat transgene at this region in Col does not alter its FLC expression. DNA methylation of the Ler allele MPF is dependent on genes in known silencing pathways, and such methylation is transmissible to Col by genetic crosses, although with varying degrees of penetrance. A genome-wide comparison of Ler and Col small RNAs identified at least 68 loci matched by a significant level of approximately 24 nt siRNAs present specifically in Ler but not Col, where nearly half of the loci are related to repeat or TE sequences. Methylation analysis revealed that 88% of the examined loci (37 out of 42 were specifically methylated in Ler but not Col, suggesting that small RNA can direct epigenetic differences between two closely related Arabidopsis ecotypes.

A Genome-Wide Association Study and Complex Network Identify Four Core Hub Genes in Bipolar Disorder

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Zengyan Xie

2017-12-01

Full Text Available Bipolar disorder is a common and severe mental illness with unsolved pathophysiology. A genome-wide association study (GWAS has been used to find a number of risk genes, but it is difficult for a GWAS to find genes indirectly associated with a disease. To find core hub genes, we introduce a network analysis after the GWAS was conducted. Six thousand four hundred fifty eight single nucleotide polymorphisms (SNPs with p < 0.01 were sifted out from Wellcome Trust Case Control Consortium (WTCCC dataset and mapped to 2045 genes, which are then compared with the protein–protein network. One hundred twelve genes with a degree >17 were chosen as hub genes from which five significant modules and four core hub genes (FBXL13, WDFY2, bFGF, and MTHFD1L were found. These core hub genes have not been reported to be directly associated with BD but may function by interacting with genes directly related to BD. Our method engenders new thoughts on finding genes indirectly associated with, but important for, complex diseases.

Expression of the lysostaphin gene of Staphylococcus simulans in a eukaryotic system.

OpenAIRE

Williamson, C M; Bramley, A J; Lax, A J

1994-01-01

The lysostaphin gene of Staphylococcus simulans was cloned into Escherichia coli. The 5' end of the gene was modified to include a eukaryotic start codon, the Kozak expression start site consensus sequence, and an enzyme site to facilitate manipulation of the gene. Transcription of the modified gene in vitro yielded an RNA transcript which, when added to a rabbit reticulocyte cell-free translation system, directed the synthesis of several products. The largest product, migrating at approximat...

Gene set analysis using variance component tests.

Science.gov (United States)

Huang, Yen-Tsung; Lin, Xihong

2013-06-28

Gene set analyses have become increasingly important in genomic research, as many complex diseases are contributed jointly by alterations of numerous genes. Genes often coordinate together as a functional repertoire, e.g., a biological pathway/network and are highly correlated. However, most of the existing gene set analysis methods do not fully account for the correlation among the genes. Here we propose to tackle this important feature of a gene set to improve statistical power in gene set analyses. We propose to model the effects of an independent variable, e.g., exposure/biological status (yes/no), on multiple gene expression values in a gene set using a multivariate linear regression model, where the correlation among the genes is explicitly modeled using a working covariance matrix. We develop TEGS (Test for the Effect of a Gene Set), a variance component test for the gene set effects by assuming a common distribution for regression coefficients in multivariate linear regression models, and calculate the p-values using permutation and a scaled chi-square approximation. We show using simulations that type I error is protected under different choices of working covariance matrices and power is improved as the working covariance approaches the true covariance. The global test is a special case of TEGS when correlation among genes in a gene set is ignored. Using both simulation data and a published diabetes dataset, we show that our test outperforms the commonly used approaches, the global test and gene set enrichment analysis (GSEA). We develop a gene set analyses method (TEGS) under the multivariate regression framework, which directly models the interdependence of the expression values in a gene set using a working covariance. TEGS outperforms two widely used methods, GSEA and global test in both simulation and a diabetes microarray data.

Archaeal promoter architecture and mechanism of gene activation

DEFF Research Database (Denmark)

Peng, Nan; Ao, Xiang; Liang, Yun Xiang

2011-01-01

element named ara box directing arabinose-inducible expression and the basal promoter element TATA, serving as the binding site for the TATA-binding protein. Strikingly, these promoters possess a modular structure that allows an essentially inactive basal promoter to be strongly activated. The invoked...... mechanisms include TFB (transcription factor B) recruitment by the ara-box-binding factor to activate gene expression and modulation of TFB recruitment efficiency to yield differential gene expression....

Differential Gene Expression of Fibroblasts: Keloid versus Normal

Directory of Open Access Journals (Sweden)

Michael F. Angel

2002-11-01

Full Text Available Abstract: This study investigated gene regulation and unique gene products in both keloid (KDF and normal (NDF dermal fibroblasts in established cell lines. For gene regulation, NDF versus KDF were compared using Clontech's Atlas™ Human cDNA Expression Array while unique gene products were studied using RNA Fingerprinting Kit. RNA from each sample was converted to cDNA using oligo-dT primers. Down-regulated genes using Atlas Array in KDF were 1 60 S ribosomal protein, 2 Thioredoxin dependent peroxidase, 3 Nuclease sensitive element DNA binding protein, 4 c-myc purine-binding transcription factor, 5 c-AMP dependent protein kinase, and, 6 Heat Shock Protein 90 kDa. Genes that are up regulated in KDF were 1 Tubulin and 2 Heat Shock Protein 27 kDa. With the differential display, we found 17 bands unique to both KDF and NDF. The specific gene and the manner in which they were differentially regulated have direct implications to understanding keloid fibroblast proliferation.

Inference of cancer-specific gene regulatory networks using soft computing rules.

Science.gov (United States)

Wang, Xiaosheng; Gotoh, Osamu

2010-03-24

Perturbations of gene regulatory networks are essentially responsible for oncogenesis. Therefore, inferring the gene regulatory networks is a key step to overcoming cancer. In this work, we propose a method for inferring directed gene regulatory networks based on soft computing rules, which can identify important cause-effect regulatory relations of gene expression. First, we identify important genes associated with a specific cancer (colon cancer) using a supervised learning approach. Next, we reconstruct the gene regulatory networks by inferring the regulatory relations among the identified genes, and their regulated relations by other genes within the genome. We obtain two meaningful findings. One is that upregulated genes are regulated by more genes than downregulated ones, while downregulated genes regulate more genes than upregulated ones. The other one is that tumor suppressors suppress tumor activators and activate other tumor suppressors strongly, while tumor activators activate other tumor activators and suppress tumor suppressors weakly, indicating the robustness of biological systems. These findings provide valuable insights into the pathogenesis of cancer.

Improved thermostability and enzyme activity of a recombinant phyA mutant phytase from Aspergillus niger N25 by directed evolution and site-directed mutagenesis.

Science.gov (United States)

Tang, Zizhong; Jin, Weiqiong; Sun, Rong; Liao, Yan; Zhen, Tianrun; Chen, Hui; Wu, Qi; Gou, Lin; Li, Chenlei

2018-01-01

We previously constructed three recombinant phyA mutant strains (PP-NP m -8, PP-NP ep -6A and I44E/T252R-PhyA), showing improved catalytic efficiency or thermostability of Aspergillus niger N25 phytase, by error-prone PCR or site-directed mutagenesis. In this study, directed evolution and site-directed mutagenesis were further applied to improve the modified phytase properties. After one-round error-prone PCR for phytase gene of PP-NP ep -6A, a single transformant, T195L/Q368E/F376Y, was obtained with the significant improvements in catalytic efficiency and thermostability. The phytase gene of T195L/Q368E/F376Y, combined with the previous mutant phytase genes of PP-NP ep -6A, PP-NP m -8 and I44E/T252R-PhyA, was then sequentially modified by DNA shuffling. Three genetically engineered strains with desirable properties were then obtained, namedQ172R, Q172R/K432R andQ368E/K432R. Among them, Q172R/K432R showed the highest thermostability with the longest half-life and the greatest remaining phytase activity after heat treatment, while Q368E/K432R showed the highest catalytic activity. Five substitutions (Q172R, T195L, Q368E, F376Y, K432R) identified from random mutagenesis were added sequentially to the phytase gene of PP-NP ep -6A to investigate how the mutant sites influence the properties of phytase. Characterization and structural analysis demonstrated that these mutations could produce cumulative or synergistic improvements in thermostability or catalytic efficiency of phytase. Copyright © 2017 Elsevier Inc. All rights reserved.

Direct detection of male quality can facilitate the evolution of female choosiness and indicators of good genes: Evolution across a continuum of indicator mechanisms.

Science.gov (United States)

Dhole, Sumit; Stern, Caitlin A; Servedio, Maria R

2018-04-01

The evolution of mating displays as indicators of male quality has been the subject of extensive theoretical and empirical research for over four decades. Research has also addressed the evolution of female mate choice favoring such indicators. Yet, much debate still exists about whether displays can evolve through the indirect benefits of female mate choice. Here, we use a population genetic model to investigate how the extent to which females can directly detect male quality influences the evolution of female choosiness and male displays. We use a continuum framework that incorporates indicator mechanisms that are traditionally modeled separately. Counter to intuition, we find that intermediate levels of direct detection of male quality can facilitate, rather than impede, the evolution of female choosiness and male displays in broad regions of this continuum. We examine how this evolution is driven by selective forces on genetic quality and on the display, and find that direct detection of male quality results in stronger indirect selection favoring female choosiness. Our results imply that displays maybe more likely to evolve when female choosiness has already evolved to discriminate perceptible forms of male quality. They also highlight the importance of considering general female choosiness, as well as preference, in studies of "good genes." © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

Differential retention of metabolic genes following whole-genome duplication.

Science.gov (United States)

Gout, Jean-François; Duret, Laurent; Kahn, Daniel

2009-05-01

Classical studies in Metabolic Control Theory have shown that metabolic fluxes usually exhibit little sensitivity to changes in individual enzyme activity, yet remain sensitive to global changes of all enzymes in a pathway. Therefore, little selective pressure is expected on the dosage or expression of individual metabolic genes, yet entire pathways should still be constrained. However, a direct estimate of this selective pressure had not been evaluated. Whole-genome duplications (WGDs) offer a good opportunity to address this question by analyzing the fates of metabolic genes during the massive gene losses that follow. Here, we take advantage of the successive rounds of WGD that occurred in the Paramecium lineage. We show that metabolic genes exhibit different gene retention patterns than nonmetabolic genes. Contrary to what was expected for individual genes, metabolic genes appeared more retained than other genes after the recent WGD, which was best explained by selection for gene expression operating on entire pathways. Metabolic genes also tend to be less retained when present at high copy number before WGD, contrary to other genes that show a positive correlation between gene retention and preduplication copy number. This is rationalized on the basis of the classical concave relationship relating metabolic fluxes with enzyme expression.

The rumen microbiome as a reservoir of antimicrobial resistance and pathogenicity genes is directly affected by diet in beef cattle.

Science.gov (United States)

Auffret, Marc D; Dewhurst, Richard J; Duthie, Carol-Anne; Rooke, John A; John Wallace, R; Freeman, Tom C; Stewart, Robert; Watson, Mick; Roehe, Rainer

2017-12-11

The emergence and spread of antimicrobial resistance is the most urgent current threat to human and animal health. An improved understanding of the abundance of antimicrobial resistance genes and genes associated with microbial colonisation and pathogenicity in the animal gut will have a major role in reducing the contribution of animal production to this problem. Here, the influence of diet on the ruminal resistome and abundance of pathogenicity genes was assessed in ruminal digesta samples taken from 50 antibiotic-free beef cattle, comprising four cattle breeds receiving two diets containing different proportions of concentrate. Two hundred and four genes associated with antimicrobial resistance (AMR), colonisation, communication or pathogenicity functions were identified from 4966 metagenomic genes using KEGG identification. Both the diversity and abundance of these genes were higher in concentrate-fed animals. Chloramphenicol and microcin resistance genes were dominant in samples from forage-fed animals (P resistances were enriched in concentrate-fed animals. The concentrate-based diet also increased the relative abundance of Proteobacteria, which includes many animal and zoonotic pathogens. A high ratio of Proteobacteria to (Firmicutes + Bacteroidetes) was confirmed as a good indicator for rumen dysbiosis, with eight cases all from concentrate-fed animals. Finally, network analysis demonstrated that the resistance/pathogenicity genes are potentially useful as biomarkers for health risk assessment of the ruminal microbiome. Diet has important effects on the complement of AMR genes in the rumen microbial community, with potential implications for human and animal health.

Adaptive differences in gene expression in European flounder ( Platichthys flesus )

DEFF Research Database (Denmark)

Larsen, Peter Foged; Eg Nielsen, Einar; Williams, T.D.

2007-01-01

levels of neutral genetic divergence, a high number of genes were significantly differentially expressed between North Sea and Baltic Sea flounders maintained in a long-term reciprocal transplantation experiment mimicking natural salinities. Several of the differentially regulated genes could be directly...... linked to fitness traits. These findings demonstrate that flounders, despite little neutral genetic divergence between populations, are differently adapted to local environmental conditions and imply that adaptation in gene expression could be common in other marine organisms with similar low levels...

Imaging the impact of genes on Parkinson's disease

DEFF Research Database (Denmark)

van der Vegt, J P M; van Nuenen, B F L; Bloem, B R

2009-01-01

by the discovery of mutations in single genes that can cause autosomal dominant (alpha-synuclein (SNCA)) and leucine rich repeat kinase 2 (LRRK2) gene) or recessive (Parkin, PTEN-induced putative kinase 1 (PINK1), DJ-1, and ATP13A2 gene) forms of PD. Here, we review how structural and functional neuroimaging...... of individuals carrying a mutation in one of the PD genes has offered a unique avenue of research into the pathogenesis of PD. In symptomatic mutation carriers (i.e. those with overt disease), brain mapping can help to link the molecular pathogenesis of PD more directly with functional and structural changes...... monogenic forms of PD, common polymorphisms in genes that influence mono-aminergic signaling or synaptic plasticity may have modifying effects on distinct aspects of PD. We also discuss how functional and structural neuroimaging can be used to better characterize these genotype-phenotype correlations....

Allopatric integrations selectively change host transcriptomes, leading to varied expression efficiencies of exotic genes in Myxococcus xanthus.

Science.gov (United States)

Zhu, Li-Ping; Yue, Xin-Jing; Han, Kui; Li, Zhi-Feng; Zheng, Lian-Shuai; Yi, Xiu-Nan; Wang, Hai-Long; Zhang, You-Ming; Li, Yue-Zhong

2015-07-22

Exotic genes, especially clustered multiple-genes for a complex pathway, are normally integrated into chromosome for heterologous expression. The influences of insertion sites on heterologous expression and allotropic expressions of exotic genes on host remain mostly unclear. We compared the integration and expression efficiencies of single and multiple exotic genes that were inserted into Myxococcus xanthus genome by transposition and attB-site-directed recombination. While the site-directed integration had a rather stable chloramphenicol acetyl transferase (CAT) activity, the transposition produced varied CAT enzyme activities. We attempted to integrate the 56-kb gene cluster for the biosynthesis of antitumor polyketides epothilones into M. xanthus genome by site-direction but failed, which was determined to be due to the insertion size limitation at the attB site. The transposition technique produced many recombinants with varied production capabilities of epothilones, which, however, were not paralleled to the transcriptional characteristics of the local sites where the genes were integrated. Comparative transcriptomics analysis demonstrated that the allopatric integrations caused selective changes of host transcriptomes, leading to varied expressions of epothilone genes in different mutants. With the increase of insertion fragment size, transposition is a more practicable integration method for the expression of exotic genes. Allopatric integrations selectively change host transcriptomes, which lead to varied expression efficiencies of exotic genes.

Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus

Science.gov (United States)

Monier, Adam; Pagarete, António; de Vargas, Colomban; Allen, Michael J.; Read, Betsy; Claverie, Jean-Michel; Ogata, Hiroyuki

2009-01-01

Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton–virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival. PMID:19451591

Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

Energy Technology Data Exchange (ETDEWEB)

Putnik, Milica, E-mail: milica.putnik@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Zhao, Chunyan, E-mail: chunyan.zhao@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Gustafsson, Jan-Ake, E-mail: jan-ake.gustafsson@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Department of Biology and Biochemistry, Science and Engineering Research Center Bldg, University of Houston, Houston, TX 77204-5056 (United States); Dahlman-Wright, Karin, E-mail: karin.dahlman-wright@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden)

2012-09-14

Highlights: Black-Right-Pointing-Pointer Estrogen signaling and demethylation can both control gene expression in breast cancers. Black-Right-Pointing-Pointer Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. Black-Right-Pointing-Pointer 137 genes are influenced by both 17{beta}-estradiol and demethylating agent 5-aza-2 Prime -deoxycytidine. Black-Right-Pointing-Pointer A set of genes is identified as targets of both estrogen signaling and demethylation. Black-Right-Pointing-Pointer There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17{beta}-estradiol (E2) and a demethylating agent 5-aza-2 Prime -deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of

Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Putnik, Milica; Zhao, Chunyan; Gustafsson, Jan-Åke; Dahlman-Wright, Karin

2012-01-01

Highlights: ► Estrogen signaling and demethylation can both control gene expression in breast cancers. ► Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. ► 137 genes are influenced by both 17β-estradiol and demethylating agent 5-aza-2′-deoxycytidine. ► A set of genes is identified as targets of both estrogen signaling and demethylation. ► There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17β-estradiol (E2) and a demethylating agent 5-aza-2′-deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of these genes in MCF-7 cells. In a further analysis of the potential interplay between estrogen signaling and DNA methylation, E2 treatment

Association and expression analyses of the Ucp2 and Ucp3 gene ...

Indian Academy of Sciences (India)

YANING WANG

5 UTR region (SNP1: g.C-754G) of the Ucp2 gene was identified by direct sequencing of 441 Qinchuan cattle. .... using SPSS 18.0 software, and Tukey's posthoc test was used ..... Polymorphism identification in goat GNRH1 and GDF9 genes.

RNA-directed DNA methylation: Mechanisms and functions

KAUST Repository

Mahfouz, Magdy M.

2010-07-01

Epigenetic RNA based gene silencing mechanisms play a major role in genome stability and control of gene expression. Transcriptional gene silencing via RNA-directed DNA methylation (RdDM) guides the epigenetic regulation of the genome in response to disease states, growth, developmental and stress signals. RdDM machinery is composed of proteins that produce and modify 24-nt- long siRNAs, recruit the RdDM complex to genomic targets, methylate DNA and remodel chromatin. The final DNA methylation pattern is determined by either DNA methyltransferase alone or by the combined action of DNA methyltransferases and demethylases. The dynamic interaction between RdDM and demethylases may render the plant epigenome plastic to growth, developmental, and environmental cues. The epigenome plasticity may allow the plant genome to assume many epigenomes and to have the right epigenome at the right time in response to intracellular or extracellular stimuli. This review discusses recent advances in RdDM research and considers future perspectives.

Genome-wide analysis of murine renal distal convoluted tubular cells for the target genes of mineralocorticoid receptor

Energy Technology Data Exchange (ETDEWEB)

Ueda, Kohei [Department of Nephrology and Endocrinology, The University of Tokyo, Tokyo (Japan); Fujiki, Katsunori; Shirahige, Katsuhiko [Research Center for Epigenetic Disease, Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo (Japan); Gomez-Sanchez, Celso E. [Endocrine Section, G.V. (Sonny) Montgomery VA Medical Center, MS (United States); Endocrinology, University of Mississippi Medical Center, MS (United States); Fujita, Toshiro [Division of Clinical Epigenetics, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo (Japan); Nangaku, Masaomi [Department of Nephrology and Endocrinology, The University of Tokyo, Tokyo (Japan); Nagase, Miki, E-mail: mnagase-tky@umin.ac.jp [Department of Nephrology and Endocrinology, The University of Tokyo, Tokyo (Japan); Department of Anatomy and Life Structure, School of Medicine Juntendo University, Tokyo (Japan)

2014-02-28

Highlights: • We define a target gene of MR as that with MR-binding to the adjacent region of DNA. • We use ChIP-seq analysis in combination with microarray. • We, for the first time, explore the genome-wide binding profile of MR. • We reveal 5 genes as the direct target genes of MR in the renal epithelial cell-line. - Abstract: Background and objective: Mineralocorticoid receptor (MR) is a member of nuclear receptor family proteins and contributes to fluid homeostasis in the kidney. Although aldosterone-MR pathway induces several gene expressions in the kidney, it is often unclear whether the gene expressions are accompanied by direct regulations of MR through its binding to the regulatory region of each gene. The purpose of this study is to identify the direct target genes of MR in a murine distal convoluted tubular epithelial cell-line (mDCT). Methods: We analyzed the DNA samples of mDCT cells overexpressing 3xFLAG-hMR after treatment with 10{sup −7} M aldosterone for 1 h by chromatin immunoprecipitation with deep-sequence (ChIP-seq) and mRNA of the cell-line with treatment of 10{sup −7} M aldosterone for 3 h by microarray. Results: 3xFLAG-hMR overexpressed in mDCT cells accumulated in the nucleus in response to 10{sup −9} M aldosterone. Twenty-five genes were indicated as the candidate target genes of MR by ChIP-seq and microarray analyses. Five genes, Sgk1, Fkbp5, Rasl12, Tns1 and Tsc22d3 (Gilz), were validated as the direct target genes of MR by quantitative RT-qPCR and ChIP-qPCR. MR binding regions adjacent to Ctgf and Serpine1 were also validated. Conclusions: We, for the first time, captured the genome-wide distribution of MR in mDCT cells and, furthermore, identified five MR target genes in the cell-line. These results will contribute to further studies on the mechanisms of kidney diseases.

Genes and Gene Therapy

Science.gov (United States)

... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

Efficient four fragment cloning for the construction of vectors for targeted gene replacement in filamentous fungi

DEFF Research Database (Denmark)

Frandsen, Rasmus John Normand; Andersson, Jens A.; Kristensen, Matilde Bylov

2008-01-01

Background: The rapid increase in whole genome fungal sequence information allows large scale functional analyses of target genes. Efficient transformation methods to obtain site-directed gene replacement, targeted over-expression by promoter replacement, in-frame epitope tagging or fusion...... of coding sequences with fluorescent markers such as GFP are essential for this process. Construction of vectors for these experiments depends on the directional cloning of two homologous recombination sequences on each side of a selection marker gene. Results: Here, we present a USER Friendly cloning based...

Bacterial Toxins for Oncoleaking Suicidal Cancer Gene Therapy.

Science.gov (United States)

Pahle, Jessica; Walther, Wolfgang

For suicide gene therapy, initially prodrug-converting enzymes (gene-directed enzyme-producing therapy, GDEPT) were employed to intracellularly metabolize non-toxic prodrugs into toxic compounds, leading to the effective suicidal killing of the transfected tumor cells. In this regard, the suicide gene therapy has demonstrated its potential for efficient tumor eradication. Numerous suicide genes of viral or bacterial origin were isolated, characterized, and extensively tested in vitro and in vivo, demonstrating their therapeutic potential even in clinical trials to treat cancers of different entities. Apart from this, growing efforts are made to generate more targeted and more effective suicide gene systems for cancer gene therapy. In this regard, bacterial toxins are an alternative to the classical GDEPT strategy, which add to the broad spectrum of different suicide approaches. In this context, lytic bacterial toxins, such as streptolysin O (SLO) or the claudin-targeted Clostridium perfringens enterotoxin (CPE) represent attractive new types of suicide oncoleaking genes. They permit as pore-forming proteins rapid and also selective toxicity toward a broad range of cancers. In this chapter, we describe the generation and use of SLO as well as of CPE-based gene therapies for the effective tumor cell eradication as promising, novel suicide gene approach particularly for treatment of therapy refractory tumors.

Large-scale extraction of gene interactions from full-text literature using DeepDive.

Science.gov (United States)

Mallory, Emily K; Zhang, Ce; Ré, Christopher; Altman, Russ B

2016-01-01

A complete repository of gene-gene interactions is key for understanding cellular processes, human disease and drug response. These gene-gene interactions include both protein-protein interactions and transcription factor interactions. The majority of known interactions are found in the biomedical literature. Interaction databases, such as BioGRID and ChEA, annotate these gene-gene interactions; however, curation becomes difficult as the literature grows exponentially. DeepDive is a trained system for extracting information from a variety of sources, including text. In this work, we used DeepDive to extract both protein-protein and transcription factor interactions from over 100,000 full-text PLOS articles. We built an extractor for gene-gene interactions that identified candidate gene-gene relations within an input sentence. For each candidate relation, DeepDive computed a probability that the relation was a correct interaction. We evaluated this system against the Database of Interacting Proteins and against randomly curated extractions. Our system achieved 76% precision and 49% recall in extracting direct and indirect interactions involving gene symbols co-occurring in a sentence. For randomly curated extractions, the system achieved between 62% and 83% precision based on direct or indirect interactions, as well as sentence-level and document-level precision. Overall, our system extracted 3356 unique gene pairs using 724 features from over 100,000 full-text articles. Application source code is publicly available at https://github.com/edoughty/deepdive_genegene_app russ.altman@stanford.edu Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

Current approaches to gene regulatory network modelling

Directory of Open Access Journals (Sweden)

Brazma Alvis

2007-09-01

Full Text Available Abstract Many different approaches have been developed to model and simulate gene regulatory networks. We proposed the following categories for gene regulatory network models: network parts lists, network topology models, network control logic models, and dynamic models. Here we will describe some examples for each of these categories. We will study the topology of gene regulatory networks in yeast in more detail, comparing a direct network derived from transcription factor binding data and an indirect network derived from genome-wide expression data in mutants. Regarding the network dynamics we briefly describe discrete and continuous approaches to network modelling, then describe a hybrid model called Finite State Linear Model and demonstrate that some simple network dynamics can be simulated in this model.

Arabidopsis RNASE THREE LIKE2 Modulates the Expression of Protein-Coding Genes via 24-Nucleotide Small Interfering RNA-Directed DNA Methylation.

Science.gov (United States)

Elvira-Matelot, Emilie; Hachet, Mélanie; Shamandi, Nahid; Comella, Pascale; Sáez-Vásquez, Julio; Zytnicki, Matthias; Vaucheret, Hervé

2016-02-01

RNaseIII enzymes catalyze the cleavage of double-stranded RNA (dsRNA) and have diverse functions in RNA maturation. Arabidopsis thaliana RNASE THREE LIKE2 (RTL2), which carries one RNaseIII and two dsRNA binding (DRB) domains, is a unique Arabidopsis RNaseIII enzyme resembling the budding yeast small interfering RNA (siRNA)-producing Dcr1 enzyme. Here, we show that RTL2 modulates the production of a subset of small RNAs and that this activity depends on both its RNaseIII and DRB domains. However, the mode of action of RTL2 differs from that of Dcr1. Whereas Dcr1 directly cleaves dsRNAs into 23-nucleotide siRNAs, RTL2 likely cleaves dsRNAs into longer molecules, which are subsequently processed into small RNAs by the DICER-LIKE enzymes. Depending on the dsRNA considered, RTL2-mediated maturation either improves (RTL2-dependent loci) or reduces (RTL2-sensitive loci) the production of small RNAs. Because the vast majority of RTL2-regulated loci correspond to transposons and intergenic regions producing 24-nucleotide siRNAs that guide DNA methylation, RTL2 depletion modifies DNA methylation in these regions. Nevertheless, 13% of RTL2-regulated loci correspond to protein-coding genes. We show that changes in 24-nucleotide siRNA levels also affect DNA methylation levels at such loci and inversely correlate with mRNA steady state levels, thus implicating RTL2 in the regulation of protein-coding gene expression. © 2016 American Society of Plant Biologists. All rights reserved.

Distribution and evolution of genes responsible for biosynthesis of mycotoxins in Fusarium

Science.gov (United States)

Fusarium secondary metabolites (SMs) include some of the mycotoxins of greatest concern to food and feed safety. In fungi, genes directly involved in synthesis of the same SM are typically located adjacent to one another in gene clusters. To better understand the distribution and evolution of mycoto...

Genetic variability of bovine GHR, IGF-1 and IGFBP-3 genes in ...

African Journals Online (AJOL)

These polymorphisms were confirmed by direct sequencing. The comparative gene sequence analysis in cattle and buffalo breeds revealed 18 single nucleotide polymorphisms (SNPs) across different loci. Eight SNPs were detected in the bovine growth hormone receptor (GHR) gene, of which four were found in the ...

A comparative analysis of soft computing techniques for gene prediction.

Science.gov (United States)

Goel, Neelam; Singh, Shailendra; Aseri, Trilok Chand

2013-07-01

The rapid growth of genomic sequence data for both human and nonhuman species has made analyzing these sequences, especially predicting genes in them, very important and is currently the focus of many research efforts. Beside its scientific interest in the molecular biology and genomics community, gene prediction is of considerable importance in human health and medicine. A variety of gene prediction techniques have been developed for eukaryotes over the past few years. This article reviews and analyzes the application of certain soft computing techniques in gene prediction. First, the problem of gene prediction and its challenges are described. These are followed by different soft computing techniques along with their application to gene prediction. In addition, a comparative analysis of different soft computing techniques for gene prediction is given. Finally some limitations of the current research activities and future research directions are provided. Copyright © 2013 Elsevier Inc. All rights reserved.

Mouse Mammary Tumor Virus Promoter-Containing Retroviral Promoter Conversion Vectors for Gene-Directed Enzyme Prodrug Therapy are Functional in Vitro and in Vivo

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Reinhard Klein

2008-01-01

Full Text Available Gene directed-enzyme prodrug therapy (GDEPT is an approach for sensitization of tumor cells to an enzymatically activated, otherwise nontoxic, prodrug. Cytochrome P450 2B1 (CYP2B1 metabolizes the prodrugs cyclophosphamide (CPA and ifosfamide (IFA to produce the cytotoxic substances phosphoramide mustard and isophosphoramide mustard as well as the byproduct acrolein. We have constructed a retroviral promoter conversion (ProCon vector for breast cancer GDEPT. The vector allows expression of CYP2B1 from the mouse mammary tumor virus (MMTV promoter known to be active in the mammary glands of transgenic animals. It is anticipated to be used for the generation of encapsulated viral vector producing cells which, when placed inside or close to a tumor, will act as suppliers of the therapeutic CYP2B1 protein as well as of the therapeutic vector itself. The generated vector was effectively packaged by virus producing cells and allowed the production of high levels of enzymatically active CYP2B1 in infected cells which sensitized them to killing upon treatment with both IFA and CPA. Determination of the respective IC50 values demonstrated that the effective IFA dose was reduced by sixteen folds. Infection efficiencies in vivo were determined using a reporter gene-bearing vector in a mammary cancer cell-derived xenograft tumor mouse model.

Gene-expression signatures of Atlantic salmon's plastic life cycle.

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Aubin-Horth, Nadia; Letcher, Benjamin H; Hofmann, Hans A

2009-09-15

How genomic expression differs as a function of life history variation is largely unknown. Atlantic salmon exhibits extreme alternative life histories. We defined the gene-expression signatures of wild-caught salmon at two different life stages by comparing the brain expression profiles of mature sneaker males and immature males, and early migrants and late migrants. In addition to life-stage-specific signatures, we discovered a surprisingly large gene set that was differentially regulated-at similar magnitudes, yet in opposite direction-in both life history transitions. We suggest that this co-variation is not a consequence of many independent cellular and molecular switches in the same direction but rather represents the molecular equivalent of a physiological shift orchestrated by one or very few master regulators.

OFFICIAL MEDICATIONS FOR ANTI-TUMOR GENE THERAPY

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E. R. Nemtsova

2016-01-01

Full Text Available This is a review of modern literature data of official medications for anti-tumor gene therapy as well as of medications that finished clinical trials.The article discusses the concept of gene therapy, the statistical analysis results of initiated clinical trials of gene products, the most actively developing directions of anticancer gene therapy, and the characteristics of anti-tumor gene medications.Various delivery systems for gene material are being examined, including viruses that are defective in  replication (Gendicine™ and Advexin and oncolytic (tumor specific conditionally replicating viruses (Oncorine™, ONYX-015, Imlygic®.By now three preparations for intra-tumor injection have been introduced into oncology clinical practice: two of them – Gendicine™ and Oncorine™ have been registered in China, and one of them – Imlygic® has been registered in the USA. Gendicine™ and Oncorine™ are based on the wild type p53 gene and are designed for treatment of patients with head and neck malignancies. Replicating adenovirus is the delivery system in Gendicine™, whereas oncolytic adenovirus is the vector for gene material in Oncorine™. Imlygic® is based on the  recombinant replicating HSV1 virus with an introduced GM–CSF gene and is designed for treatment of  melanoma patients. These medications are well tolerated and do not cause any serious adverse events. Gendicine™ and Oncorine™ are not effective in monotherapy but demonstrate pronounced synergism with chemoand radiation therapy. Imlygic® has just started the post marketing trials.

A strong deletion bias in nonallelic gene conversion.

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Raquel Assis

Full Text Available Gene conversion is the unidirectional transfer of genetic information between orthologous (allelic or paralogous (nonallelic genomic segments. Though a number of studies have examined nucleotide replacements, little is known about length difference mutations produced by gene conversion. Here, we investigate insertions and deletions produced by nonallelic gene conversion in 338 Drosophila and 10,149 primate paralogs. Using a direct phylogenetic approach, we identify 179 insertions and 614 deletions in Drosophila paralogs, and 132 insertions and 455 deletions in primate paralogs. Thus, nonallelic gene conversion is strongly deletion-biased in both lineages, with almost 3.5 times as many conversion-induced deletions as insertions. In primates, the deletion bias is considerably stronger for long indels and, in both lineages, the per-site rate of gene conversion is orders of magnitudes higher than that of ordinary mutation. Due to this high rate, deletion-biased nonallelic gene conversion plays a key role in genome size evolution, leading to the cooperative shrinkage and eventual disappearance of selectively neutral paralogs.

A quantitative and dynamic model of the Arabidopsis flowering time gene regulatory network.

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Felipe Leal Valentim

Full Text Available Various environmental signals integrate into a network of floral regulatory genes leading to the final decision on when to flower. Although a wealth of qualitative knowledge is available on how flowering time genes regulate each other, only a few studies incorporated this knowledge into predictive models. Such models are invaluable as they enable to investigate how various types of inputs are combined to give a quantitative readout. To investigate the effect of gene expression disturbances on flowering time, we developed a dynamic model for the regulation of flowering time in Arabidopsis thaliana. Model parameters were estimated based on expression time-courses for relevant genes, and a consistent set of flowering times for plants of various genetic backgrounds. Validation was performed by predicting changes in expression level in mutant backgrounds and comparing these predictions with independent expression data, and by comparison of predicted and experimental flowering times for several double mutants. Remarkably, the model predicts that a disturbance in a particular gene has not necessarily the largest impact on directly connected genes. For example, the model predicts that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS (SOC1 mutation has a larger impact on APETALA1 (AP1, which is not directly regulated by SOC1, compared to its effect on LEAFY (LFY which is under direct control of SOC1. This was confirmed by expression data. Another model prediction involves the importance of cooperativity in the regulation of APETALA1 (AP1 by LFY, a prediction supported by experimental evidence. Concluding, our model for flowering time gene regulation enables to address how different quantitative inputs are combined into one quantitative output, flowering time.

Inference of Cancer-specific Gene Regulatory Networks Using Soft Computing Rules

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Xiaosheng Wang

2010-03-01

Full Text Available Perturbations of gene regulatory networks are essentially responsible for oncogenesis. Therefore, inferring the gene regulatory networks is a key step to overcoming cancer. In this work, we propose a method for inferring directed gene regulatory networks based on soft computing rules, which can identify important cause-effect regulatory relations of gene expression. First, we identify important genes associated with a specific cancer (colon cancer using a supervised learning approach. Next, we reconstruct the gene regulatory networks by inferring the regulatory relations among the identified genes, and their regulated relations by other genes within the genome. We obtain two meaningful findings. One is that upregulated genes are regulated by more genes than downregulated ones, while downregulated genes regulate more genes than upregulated ones. The other one is that tumor suppressors suppress tumor activators and activate other tumor suppressors strongly, while tumor activators activate other tumor activators and suppress tumor suppressors weakly, indicating the robustness of biological systems. These findings provide valuable insights into the pathogenesis of cancer.

Direct Transcriptional Consequences of Somatic Mutation in Breast Cancer

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Adam Shlien

2016-08-01

Full Text Available Disordered transcriptomes of cancer encompass direct effects of somatic mutation on transcription, coordinated secondary pathway alterations, and increased transcriptional noise. To catalog the rules governing how somatic mutation exerts direct transcriptional effects, we developed an exhaustive pipeline for analyzing RNA sequencing data, which we integrated with whole genomes from 23 breast cancers. Using X-inactivation analyses, we found that cancer cells are more transcriptionally active than intermixed stromal cells. This is especially true in estrogen receptor (ER-negative tumors. Overall, 59% of substitutions were expressed. Nonsense mutations showed lower expression levels than expected, with patterns characteristic of nonsense-mediated decay. 14% of 4,234 rearrangements caused transcriptional abnormalities, including exon skips, exon reusage, fusions, and premature polyadenylation. We found productive, stable transcription from sense-to-antisense gene fusions and gene-to-intergenic rearrangements, suggesting that these mutation classes drive more transcriptional disruption than previously suspected. Systematic integration of transcriptome with genome data reveals the rules by which transcriptional machinery interprets somatic mutation.

Identifying footprints of directional and balancing selection in marine and freshwater three-spined stickleback (Gasterosteus aculeatus) populations.

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Mäkinen, H S; Cano, J M; Merilä, J

2008-08-01

Natural selection is expected to leave an imprint on the neutral polymorphisms at the adjacent genomic regions of a selected gene. While directional selection tends to reduce within-population genetic diversity and increase among-population differentiation, the reverse is expected under balancing selection. To identify targets of natural selection in the three-spined stickleback (Gasterosteus aculeatus) genome, 103 microsatellite and two indel markers including expressed sequence tags (EST) and quantitative trait loci (QTL)-associated loci, were genotyped in four freshwater and three marine populations. The results indicated that a high proportion of loci (14.7%) might be affected by balancing selection and a lower proportion (2.8%) by directional selection. The strongest signatures of directional selection were detected in a microsatellite locus and two indel markers located in the intronic regions of the Eda-gene coding for the number of lateral plates. Yet, other microsatellite loci previously found to be informative in QTL-mapping studies revealed no signatures of selection. Two novel microsatellite loci (Stn12 and Stn90) located in chromosomes I and VIII, respectively, showed signals of directional selection and might be linked to genomic regions containing gene(s) important for adaptive divergence. Although the coverage of the total genomic content was relatively low, the predominance of balancing selection signals is in agreement with the contention that balancing, rather than directional selection is the predominant mode of selection in the wild.

Polycistronic gene expression in Aspergillus niger.

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Schuetze, Tabea; Meyer, Vera

2017-09-25

Genome mining approaches predict dozens of biosynthetic gene clusters in each of the filamentous fungal genomes sequenced so far. However, the majority of these gene clusters still remain cryptic because they are not expressed in their natural host. Simultaneous expression of all genes belonging to a biosynthetic pathway in a heterologous host is one approach to activate biosynthetic gene clusters and to screen the metabolites produced for bioactivities. Polycistronic expression of all pathway genes under control of a single and tunable promoter would be the method of choice, as this does not only simplify cloning procedures, but also offers control on timing and strength of expression. However, polycistronic gene expression is a feature not commonly found in eukaryotic host systems, such as Aspergillus niger. In this study, we tested the suitability of the viral P2A peptide for co-expression of three genes in A. niger. Two genes descend from Fusarium oxysporum and are essential to produce the secondary metabolite enniatin (esyn1, ekivR). The third gene (luc) encodes the reporter luciferase which was included to study position effects. Expression of the polycistronic gene cassette was put under control of the Tet-On system to ensure tunable gene expression in A. niger. In total, three polycistronic expression cassettes which differed in the position of luc were constructed and targeted to the pyrG locus in A. niger. This allowed direct comparison of the luciferase activity based on the position of the luciferase gene. Doxycycline-mediated induction of the Tet-On expression cassettes resulted in the production of one long polycistronic mRNA as proven by Northern analyses, and ensured comparable production of enniatin in all three strains. Notably, gene position within the polycistronic expression cassette matters, as, luciferase activity was lowest at position one and had a comparable activity at positions two and three. The P2A peptide can be used to express at

Sex-based differences in gene expression in hippocampus following postnatal lead exposure

International Nuclear Information System (INIS)

Schneider, J.S.; Anderson, D.W.; Sonnenahalli, H.; Vadigepalli, R.

2011-01-01

The influence of sex as an effect modifier of childhood lead poisoning has received little systematic attention. Considering the paucity of information available concerning the interactive effects of lead and sex on the brain, the current study examined the interactive effects of lead and sex on gene expression patterns in the hippocampus, a structure involved in learning and memory. Male or female rats were fed either 1500 ppm lead-containing chow or control chow for 30 days beginning at weaning.Blood lead levels were 26.7 ± 2.1 μg/dl and 27.1 ± 1.7 μg/dl for females and males, respectively. The expression of 175 unique genes was differentially regulated between control male and female rats. A total of 167 unique genes were differentially expressed in response to lead in either males or females. Lead exposure had a significant effect without a significant difference between male and female responses in 77 of these genes. In another set of 71 genes, there were significant differences in male vs. female response. A third set of 30 genes was differentially expressed in opposite directions in males vs. females, with the majority of genes expressed at a lower level in females than in males. Highly differentially expressed genes in males and females following lead exposure were associated with diverse biological pathways and functions. These results show that a brief exposure to lead produced significant changes in expression of a variety of genes in the hippocampus and that the response of the brain to a given lead exposure may vary depending on sex. - Highlights: → Postnatal lead exposure has a significant effect on hippocampal gene expression patterns. → At least one set of genes was affected in opposite directions in males and females. → Differentially expressed genes were associated with diverse biological pathways.

Regulatory role of tetR gene in a novel gene cluster of Acidovorax avenae subsp. avenae RS-1 under oxidative stress

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He eLiu

2014-10-01

Full Text Available Acidovorax avenae subsp. avenae is the causal agent of bacterial brown stripe disease in rice. In this study, we characterized a novel horizontal transfer of a gene cluster, including tetR, on the chromosome of A. avenae subsp. avenae RS-1 by genome-wide analysis. TetR acted as a repressor in this gene cluster and the oxidative stress resistance was enhanced in tetR-deletion mutant strain. Electrophoretic mobility shift assay (EMSA demonstrated that TetR regulator bound directly to the promoter of this gene cluster. Consistently, the results of quantitative real-time PCR also showed alterations in expression of associated genes. Moreover, the proteins affected by TetR under oxidative stress were revealed by comparing proteomic profiles of wild-type and mutant strains via 1D SDS-PAGE and LC-MS/MS analyses. Taken together, our results demonstrated that tetR gene in this novel gene cluster contributed to cell survival under oxidative stress, and TetR protein played an important regulatory role in growth kinetics, biofilm-forming capability, SOD and catalase activity, and oxide detoxicating ability.

Regulatory role of tetR gene in a novel gene cluster of Acidovorax avenae subsp. avenae RS-1 under oxidative stress.

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Liu, He; Yang, Chun-Lan; Ge, Meng-Yu; Ibrahim, Muhammad; Li, Bin; Zhao, Wen-Jun; Chen, Gong-You; Zhu, Bo; Xie, Guan-Lin

2014-01-01

Acidovorax avenae subsp. avenae is the causal agent of bacterial brown stripe disease in rice. In this study, we characterized a novel horizontal transfer of a gene cluster, including tetR, on the chromosome of A. avenae subsp. avenae RS-1 by genome-wide analysis. TetR acted as a repressor in this gene cluster and the oxidative stress resistance was enhanced in tetR-deletion mutant strain. Electrophoretic mobility shift assay demonstrated that TetR regulator bound directly to the promoter of this gene cluster. Consistently, the results of quantitative real-time PCR also showed alterations in expression of associated genes. Moreover, the proteins affected by TetR under oxidative stress were revealed by comparing proteomic profiles of wild-type and mutant strains via 1D SDS-PAGE and LC-MS/MS analyses. Taken together, our results demonstrated that tetR gene in this novel gene cluster contributed to cell survival under oxidative stress, and TetR protein played an important regulatory role in growth kinetics, biofilm-forming capability, superoxide dismutase and catalase activity, and oxide detoxicating ability.

HOX Gene Promoter Prediction and Inter-genomic Comparison: An Evo-Devo Study

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Marla A. Endriga

2010-10-01

Full Text Available Homeobox genes direct the anterior-posterior axis of the body plan in eukaryotic organisms. Promoter regions upstream of the Hox genes jumpstart the transcription process. CpG islands found within the promoter regions can cause silencing of these promoters. The locations of the promoter regions and the CpG islands of Homeo sapiens sapiens (human, Pan troglodytes (chimpanzee, Mus musculus (mouse, and Rattus norvegicus (brown rat are compared and related to the possible influence on the specification of the mammalian body plan. The sequence of each gene in Hox clusters A-D of the mammals considered were retrieved from Ensembl and locations of promoter regions and CpG islands predicted using Exon Finder. The predicted promoter sequences were confirmed via BLAST and verified against the Eukaryotic Promoter Database. The significance of the locations was determined using the Kruskal-Wallis test. Among the four clusters, only promoter locations in cluster B showed significant difference. HOX B genes have been linked with the control of genes that direct the development of axial morphology, particularly of the vertebral column bones. The magnitude of variation among the body plans of closely-related species can thus be partially attributed to the promoter kind, location and number, and gene inactivation via CpG methylation.

Regulatory role of tetR gene in a novel gene cluster of Acidovorax avenae subsp. avenae RS-1 under oxidative stress

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Liu, He; Yang, Chun-Lan; Ge, Meng-Yu; Ibrahim, Muhammad; Li, Bin; Zhao, Wen-Jun; Chen, Gong-You; Zhu, Bo; Xie, Guan-Lin

2014-01-01

Acidovorax avenae subsp. avenae is the causal agent of bacterial brown stripe disease in rice. In this study, we characterized a novel horizontal transfer of a gene cluster, including tetR, on the chromosome of A. avenae subsp. avenae RS-1 by genome-wide analysis. TetR acted as a repressor in this gene cluster and the oxidative stress resistance was enhanced in tetR-deletion mutant strain. Electrophoretic mobility shift assay demonstrated that TetR regulator bound directly to the promoter of ...

Peroxisome Proliferator-Activated Receptor Alpha Target Genes

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Maryam Rakhshandehroo

2010-01-01

Full Text Available The peroxisome proliferator-activated receptor alpha (PPARα is a ligand-activated transcription factor involved in the regulation of a variety of processes, ranging from inflammation and immunity to nutrient metabolism and energy homeostasis. PPARα serves as a molecular target for hypolipidemic fibrates drugs which bind the receptor with high affinity. Furthermore, PPARα binds and is activated by numerous fatty acids and fatty acid-derived compounds. PPARα governs biological processes by altering the expression of a large number of target genes. Accordingly, the specific role of PPARα is directly related to the biological function of its target genes. Here, we present an overview of the involvement of PPARα in lipid metabolism and other pathways through a detailed analysis of the different known or putative PPARα target genes. The emphasis is on gene regulation by PPARα in liver although many of the results likely apply to other organs and tissues as well.

Experimental Model of Gene Transfection in Healthy Canine Myocardium: Perspectives of Gene Therapy for Ischemic Heart Disease

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Renato A. K. Kalil

2002-09-01

Full Text Available OBJECTIVE: To assess the transfection of the gene that encodes green fluorescent protein (GFP through direct intramyocardial injection. METHODS: The pREGFP plasmid vector was used. The EGFP gene was inserted downstream from the constitutive promoter of the Rous sarcoma virus. Five male dogs were used (mean weight 13.5 kg, in which 0.5 mL of saline solution (n=1 or 0.5 mL of plasmid solution containing 0.5 µg of pREGFP/dog (n=4 were injected into the myocardium of the left ventricular lateral wall. The dogs were euthanized 1 week later, and cardiac biopsies were obtained. RESULTS: Fluorescence microscopy showed differences between the cells transfected and not transfected with pREGFP plasmid. Mild fluorescence was observed in the cardiac fibers that received saline solution; however, the myocardial cells transfected with pREGFP had overt EGFP expression. CONCLUSION: Transfection with the EGFP gene in healthy canine myocardium was effective. The reproduction of this efficacy using vascular endothelial growth factor (VEGF instead of EGFP aims at developing gene therapy for ischemic heart disease.

Correction of Fanconi Anemia Group C Hematopoietic Stem Cells Following Intrafemoral Gene Transfer

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Ouassila Habi

2010-01-01

Full Text Available The main cause of morbidity and mortality in Fanconi anemia patients is the development of bone marrow (BM failure; thus correction of hematopoietic stem cells (HSCs through gene transfer approaches would benefit FA patients. However, gene therapy trials for FA patients using ex vivo transduction protocols have failed to provide long-term correction. In addition, ex vivo cultures have been found to be hazardous for FA cells. To circumvent negative effects of ex vivo culture in FA stem cells, we tested the corrective ability of direct injection of recombinant lentiviral particles encoding FancC-EGFP into femurs of FancC−/− mice. Using this approach, we show that FancC−/− HSCs were efficiently corrected. Intrafemoral gene transfer of the FancC gene prevented the mitomycin C-induced BM failure. Moreover, we show that intrafemoral gene delivery into aplastic marrow restored the bone marrow cellularity and corrected the remaining HSCs. These results provide evidence that targeting FA-deficient HSCs directly in their environment enables efficient and long-term correction of BM defects in FA.

Hox gene function and interaction in the milkweed bug Oncopeltus fasciatus (Hemiptera).

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Angelini, David R; Liu, Paul Z; Hughes, Cynthia L; Kaufman, Thomas C

2005-11-15

Studies in genetic model organisms such as Drosophila have demonstrated that the homeotic complex (Hox) genes impart segmental identity during embryogenesis. Comparative studies in a wide range of other insect taxa have shown that the Hox genes are expressed in largely conserved domains along the anterior-posterior body axis, but whether they are performing the same functions in different insects is an open question. Most of the Hox genes have been studied functionally in only a few holometabolous insects that undergo metamorphosis. Thus, it is unclear how the Hox genes are functioning in the majority of direct-developing insects and other arthropods. To address this question, we used a combination of RNAi and in situ hybridization to reveal the expression, functions, and regulatory interactions of the Hox genes in the milkweed bug Oncopeltus fasciatus. Our results reveal many similarities and some interesting differences compared to Drosophila. We find that the gene Antennapedia is required for the identity of all three thoracic segments, while Ultrabithorax, abdominal-A and Abdominal-B cooperate to pattern the abdomen. The three abdominal genes exhibit posterior prevalence like in Drosophila, but apparently via some post-transcriptional mechanism. The functions of the head genes proboscipedia, Deformed, and Sex combs reduced were shown previously, and here we find that the complex temporal expression of pb in the labium is like that of other insects, but its regulatory relationship with Scr is unique. Overall, our data reveal that the evolution of insect Hox genes has included many small changes within general conservation of expression and function, and that the milkweed bug provides a useful model for understanding the roles of Hox genes in a direct-developing insect.

Empirical validation of the S-Score algorithm in the analysis of gene expression data

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Archer Kellie J

2006-03-01

Full Text Available Abstract Background Current methods of analyzing Affymetrix GeneChip® microarray data require the estimation of probe set expression summaries, followed by application of statistical tests to determine which genes are differentially expressed. The S-Score algorithm described by Zhang and colleagues is an alternative method that allows tests of hypotheses directly from probe level data. It is based on an error model in which the detected signal is proportional to the probe pair signal for highly expressed genes, but approaches a background level (rather than 0 for genes with low levels of expression. This model is used to calculate relative change in probe pair intensities that converts probe signals into multiple measurements with equalized errors, which are summed over a probe set to form the S-Score. Assuming no expression differences between chips, the S-Score follows a standard normal distribution, allowing direct tests of hypotheses to be made. Using spike-in and dilution datasets, we validated the S-Score method against comparisons of gene expression utilizing the more recently developed methods RMA, dChip, and MAS5. Results The S-score showed excellent sensitivity and specificity in detecting low-level gene expression changes. Rank ordering of S-Score values more accurately reflected known fold-change values compared to other algorithms. Conclusion The S-score method, utilizing probe level data directly, offers significant advantages over comparisons using only probe set expression summaries.

Robustness and accuracy in sea urchin developmental gene regulatory networks

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Smadar eBen-Tabou De-Leon

2016-02-01

Full Text Available Developmental gene regulatory networks robustly control the timely activation of regulatory and differentiation genes. The structure of these networks underlies their capacity to buffer intrinsic and extrinsic noise and maintain embryonic morphology. Here I illustrate how the use of specific architectures by the sea urchin developmental regulatory networks enables the robust control of cell fate decisions. The Wnt-βcatenin signaling pathway patterns the primary embryonic axis while the BMP signaling pathway patterns the secondary embryonic axis in the sea urchin embryo and across bilateria. Interestingly, in the sea urchin in both cases, the signaling pathway that defines the axis controls directly the expression of a set of downstream regulatory genes. I propose that this direct activation of a set of regulatory genes enables a uniform regulatory response and a clear cut cell fate decision in the endoderm and in the dorsal ectoderm. The specification of the mesodermal pigment cell lineage is activated by Delta signaling that initiates a triple positive feedback loop that locks down the pigment specification state. I propose that the use of compound positive feedback circuitry provides the endodermal cells enough time to turn off mesodermal genes and ensures correct mesoderm vs. endoderm fate decision. Thus, I argue that understanding the control properties of repeatedly used regulatory architectures illuminates their role in embryogenesis and provides possible explanations to their resistance to evolutionary change.

Structure and regulated expression of bovine prolactin and bovine growth hormone genes

International Nuclear Information System (INIS)

Rottman, F.; Camper, S.; Goodwin, E.; Hampson, R.; Lyons, R.

1986-01-01

This paper presents a description of several studies which utilize the transfection of cloned chimeric genes in an attempt to analyze the regulatory signals found in the bPRL and bGH genes. Examination of 5' flanking region of PRL genes reveals a high degree of sequence homology between the bovine, human, and rat species. In order to assess the existence of possible regulatory sequences in a more direct manner, the authors transfected homologous and heterologous cells with chimeric gene constructs containing possible regulatory sequences derived from both the bPRL and bGH genes. An analysis is presented of the polyadenylation signal contained in the bGH 3' flanking sequence

Dual-therapeutic reporter genes fusion for enhanced cancer gene therapy and imaging.

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Sekar, T V; Foygel, K; Willmann, J K; Paulmurugan, R

2013-05-01

Two of the successful gene-directed enzyme prodrug therapies include herpes simplex virus-thymidine kinase (HSV1-TK) enzyme-ganciclovir prodrug and the Escherichia coli nitroreductase (NTR) enzyme-CB1954 prodrug strategies; these enzyme-prodrug combinations produce activated cytotoxic metabolites of the prodrugs capable of tumor cell death by inhibiting DNA synthesis and killing quiescent cells, respectively. Both these strategies also affect significant bystander cell killing of neighboring tumor cells that do not express these enzymes. We have developed a dual-combination gene strategy, where we identified HSV1-TK and NTR fused in a particular orientation can effectively kill tumor cells when the tumor cells are treated with a fusion HSV1-TK-NTR gene- along with a prodrug combination of GCV and CB1954. In order to determine whether the dual-system demonstrate superior therapeutic efficacy than either HSV1-TK or NTR systems alone, we conducted both in vitro and in vivo tumor xenograft studies using triple negative SUM159 breast cancer cells, by evaluating the efficacy of cell death by apoptosis and necrosis upon treatment with the dual HSV1-TK genes-GCV-CB1954 prodrugs system, and compared the efficiency to HSV1-TK-GCV and NTR-CB1954. Our cell-based studies, tumor regression studies in xenograft mice, histological analyses of treated tumors and bystander studies indicate that the dual HSV1-TK-NTR-prodrug system is two times more efficient even with half the doses of both prodrugs than the respective single gene-prodrug system, as evidenced by enhanced apoptosis and necrosis of tumor cells in vitro in culture and xenograft of tumor tissues in animals.

PCR cloning of Polyhydroxybutyrate Synthase Gene (phbC) from Aeromonashydrophila

International Nuclear Information System (INIS)

Enan, M. R.; Bashandy, S.A.

2006-01-01

Plastic wastes are considered to be severe environmental contaminantscausing waste disposal problems. Widespread use of biodegradable plastics isone of the solutions, but it is limited by high production cost. A polymerasechain reaction (PCR) protocol was developed for the specific for the specificdetection and isolation of full-length gene coding for polyhydroxybutyrate(PBH). (PCR) strategy using (PHB) primers resulted in the amplification of(DNA) fragments with the expected size from all isolated bacteria (PBH)synthase gene was cloned directly from Aeromonas hydrophila genome for thefirst time. The clonec fragment was named (phbCAh) gene exhibits similarly to(PHB) synthase genes of Alcaligenes latus and Pseudomonas oleovorans (97%),Alcaligenes sp. (81%) and Comamonas acidovorans (84%). (author)

Serial analysis of gene expression (SAGE) in rat liver regeneration

International Nuclear Information System (INIS)

Cimica, Velasco; Batusic, Danko; Haralanova-Ilieva, Borislava; Chen, Yonglong; Hollemann, Thomas; Pieler, Tomas; Ramadori, Giuliano

2007-01-01

We have applied serial analysis of gene expression for studying the molecular mechanism of the rat liver regeneration in the model of 70% partial hepatectomy. We generated three SAGE libraries from a normal control liver (NL library: 52,343 tags), from a sham control operated liver (Sham library: 51,028 tags), and from a regenerating liver (PH library: 53,061 tags). By SAGE bioinformatics analysis we identified 40 induced genes and 20 repressed genes during the liver regeneration. We verified temporal expression of such genes by real time PCR during the regeneration process and we characterized 13 induced genes and 3 repressed genes. We found connective tissue growth factor transcript and protein induced very early at 4 h after PH operation before hepatocytes proliferation is triggered. Our study suggests CTGF as a growth factor signaling mediator that could be involved directly in the mechanism of liver regeneration induction

Evolutionary analysis of the kinesin light chain genes in the yellow fever mosquito Aedes aegypti: gene duplication as a source for novel early zygotic genes.

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Biedler, James K; Tu, Zhijian

2010-07-08

The maternal zygotic transition marks the time at which transcription from the zygotic genome is initiated and a subset of maternal RNAs are progressively degraded in the developing embryo. A number of early zygotic genes have been identified in Drosophila melanogaster and comparisons to sequenced mosquito genomes suggest that some of these early zygotic genes such as bottleneck are fast-evolving or subject to turnover in dipteran insects. One objective of this study is to identify early zygotic genes from the yellow fever mosquito Aedes aegypti to study their evolution. We are also interested in obtaining early zygotic promoters that will direct transgene expression in the early embryo as part of a Medea gene drive system. Two novel early zygotic kinesin light chain genes we call AaKLC2.1 and AaKLC2.2 were identified by transcriptome sequencing of Aedes aegypti embryos at various time points. These two genes have 98% nucleotide and amino acid identity in their coding regions and show transcription confined to the early zygotic stage according to gene-specific RT-PCR analysis. These AaKLC2 genes have a paralogous gene (AaKLC1) in Ae. aegypti. Phylogenetic inference shows that an ortholog to the AaKLC2 genes is only found in the sequenced genome of Culex quinquefasciatus. In contrast, AaKLC1 gene orthologs are found in all three sequenced mosquito species including Anopheles gambiae. There is only one KLC gene in D. melanogaster and other sequenced holometabolous insects that appears to be similar to AaKLC1. Unlike AaKLC2, AaKLC1 is expressed in all life stages and tissues tested, which is consistent with the expression pattern of the An. gambiae and D. melanogaster KLC genes. Phylogenetic inference also suggests that AaKLC2 genes and their likely C. quinquefasciatus ortholog are fast-evolving genes relative to the highly conserved AaKLC1-like paralogs. Embryonic injection of a luciferase reporter under the control of a 1 kb fragment upstream of the AaKLC2.1 start

Evolutionary analysis of the kinesin light chain genes in the yellow fever mosquito Aedes aegypti: gene duplication as a source for novel early zygotic genes

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Tu Zhijian

2010-07-01

Full Text Available Abstract Background The maternal zygotic transition marks the time at which transcription from the zygotic genome is initiated and a subset of maternal RNAs are progressively degraded in the developing embryo. A number of early zygotic genes have been identified in Drosophila melanogaster and comparisons to sequenced mosquito genomes suggest that some of these early zygotic genes such as bottleneck are fast-evolving or subject to turnover in dipteran insects. One objective of this study is to identify early zygotic genes from the yellow fever mosquito Aedes aegypti to study their evolution. We are also interested in obtaining early zygotic promoters that will direct transgene expression in the early embryo as part of a Medea gene drive system. Results Two novel early zygotic kinesin light chain genes we call AaKLC2.1 and AaKLC2.2 were identified by transcriptome sequencing of Aedes aegypti embryos at various time points. These two genes have 98% nucleotide and amino acid identity in their coding regions and show transcription confined to the early zygotic stage according to gene-specific RT-PCR analysis. These AaKLC2 genes have a paralogous gene (AaKLC1 in Ae. aegypti. Phylogenetic inference shows that an ortholog to the AaKLC2 genes is only found in the sequenced genome of Culex quinquefasciatus. In contrast, AaKLC1 gene orthologs are found in all three sequenced mosquito species including Anopheles gambiae. There is only one KLC gene in D. melanogaster and other sequenced holometabolous insects that appears to be similar to AaKLC1. Unlike AaKLC2, AaKLC1 is expressed in all life stages and tissues tested, which is consistent with the expression pattern of the An. gambiae and D. melanogaster KLC genes. Phylogenetic inference also suggests that AaKLC2 genes and their likely C. quinquefasciatus ortholog are fast-evolving genes relative to the highly conserved AaKLC1-like paralogs. Embryonic injection of a luciferase reporter under the control of a

The organization structure and regulatory elements of Chlamydomonas histone genes reveal features linking plant and animal genes.

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Fabry, S; Müller, K; Lindauer, A; Park, P B; Cornelius, T; Schmitt, R

1995-09-01

The genome of the green alga Chlamydomonas reinhardtii contains approximately 15 gene clusters of the nucleosomal (or core) histone H2A, H2B, H3 and H4 genes and at least one histone H1 gene. Seven non-allelic histone gene loci were isolated from a genomic library, physically mapped, and the nucleotide sequences of three isotypes of each core histone gene species and one linked H1 gene determined. The core histone genes are organized in clusters of H2A-H2B and H3-H4 pairs, in which each gene pair shows outwardly divergent transcription from a short (< 300 bp) intercistronic region. These intercistronic regions contain typically conserved promoter elements, namely a TATA-box and the three motifs TGGCCAG-G(G/C)-CGAG, CGTTGACC and CGGTTG. Different from the genes of higher plants, but like those of animals and the related alga Volvox, the 3' untranslated regions contain no poly A signal, but a palindromic sequence (3' palindrome) essential for mRNA processing is present. One single H1 gene was found in close linkage to a H2A-H2B pair. The H1 upstream region contains the octameric promoter element GGTTGACC (also found upstream of the core histone genes) and two specific sequence motifs that are shared only with the Volvox H1 promoters. This suggests differential transcription of the H1 and the core histone genes. The H1 gene is interrupted by two introns. Unlike Volvox H3 genes, the three sequenced H3 isoforms are intron-free. Primer-directed PCR of genomic DNA demonstrated, however, that at least 8 of the about 15 H3 genes do contain one intron at a conserved position. In synchronized C. reinhardtii cells, H4 mRNA levels (representative of all core histone mRNAs) peak during cell division, suggesting strict replication-dependent gene control. The derived peptide sequences place C. reinhardtii core histones closer to plants than to animals, except that the H2A histones are more animal-like. The peptide sequence of histone H1 is closely related to the V. carteri VH1-II

Integrative Functional Genomics for Systems Genetics in GeneWeaver.org.

Science.gov (United States)

Bubier, Jason A; Langston, Michael A; Baker, Erich J; Chesler, Elissa J

2017-01-01

The abundance of existing functional genomics studies permits an integrative approach to interpreting and resolving the results of diverse systems genetics studies. However, a major challenge lies in assembling and harmonizing heterogeneous data sets across species for facile comparison to the positional candidate genes and coexpression networks that come from systems genetic studies. GeneWeaver is an online database and suite of tools at www.geneweaver.org that allows for fast aggregation and analysis of gene set-centric data. GeneWeaver contains curated experimental data together with resource-level data such as GO annotations, MP annotations, and KEGG pathways, along with persistent stores of user entered data sets. These can be entered directly into GeneWeaver or transferred from widely used resources such as GeneNetwork.org. Data are analyzed using statistical tools and advanced graph algorithms to discover new relations, prioritize candidate genes, and generate function hypotheses. Here we use GeneWeaver to find genes common to multiple gene sets, prioritize candidate genes from a quantitative trait locus, and characterize a set of differentially expressed genes. Coupling a large multispecies repository curated and empirical functional genomics data to fast computational tools allows for the rapid integrative analysis of heterogeneous data for interpreting and extrapolating systems genetics results.

Re-Examining the Gene in Personalized Genomics

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Bartol, Jordan

2013-01-01

Personalized genomics companies (PG; also called "direct-to-consumer genetics") are businesses marketing genetic testing to consumers over the Internet. While much has been written about these new businesses, little attention has been given to their roles in science communication. This paper provides an analysis of the gene concept…

Re-examining the Gene in Personalized Genomics

Science.gov (United States)

Bartol, Jordan

2013-10-01

Personalized genomics companies (PG; also called `direct-to-consumer genetics') are businesses marketing genetic testing to consumers over the Internet. While much has been written about these new businesses, little attention has been given to their roles in science communication. This paper provides an analysis of the gene concept presented to customers and the relation between the information given and the science behind PG. Two quite different gene concepts are present in company rhetoric, but only one features in the science. To explain this, we must appreciate the delicate tension between PG, academic science, public expectation, and market forces.

Gene-expression signatures of Atlantic salmon's plastic life cycle

Science.gov (United States)

Aubin-Horth, N.; Letcher, B.H.; Hofmann, H.A.

2009-01-01

How genomic expression differs as a function of life history variation is largely unknown. Atlantic salmon exhibits extreme alternative life histories. We defined the gene-expression signatures of wild-caught salmon at two different life stages by comparing the brain expression profiles of mature sneaker males and immature males, and early migrants and late migrants. In addition to life-stage-specific signatures, we discovered a surprisingly large gene set that was differentially regulated-at similar magnitudes, yet in opposite direction-in both life history transitions. We suggest that this co-variation is not a consequence of many independent cellular and molecular switches in the same direction but rather represents the molecular equivalent of a physiological shift orchestrated by one or very few master regulators. ?? 2009 Elsevier Inc. All rights reserved.

Efficient adenoviral vector directed expression of a foreign gene to neurons and sustentacular cells in the mouse olfactory neuroepithelium

NARCIS (Netherlands)

Gispen, W.H.; Holtmaat, A.J.G.D.; Hermens, W.T.J.M.C.; Oestreicher, A.B.; Kaplitt, M.G.; Verhaagen, J.

1996-01-01

Replication deficient recombinant adenoviral vectors are efficient gene transfer agents for postmitotic cells, including neurons and glial cells. In this paper we have examined the effectiveness of adenoviral vector-mediated gene transfer to the olfactory epithelium of adult mice. We show that

Efficient adenoviral vector-directed expression of a foreign gene to neurons and sustentacular cells in the mouse olfactory neuroepithelium

NARCIS (Netherlands)

Holtmaat, Anthony J D G; Hermens, W.T.J.M.C.; Oestreicher, A B; Gispen, Willem Hendrik; Kaplitt, M G; Verhaagen, J

1996-01-01

Replication deficient recombinant adenoviral vectors are efficient gene transfer agents for postmitotic cells, including neurons and glial cells. In this paper we have examined the effectiveness of adenoviral vector-mediated gene transfer to the olfactory epithelium of adult mice. We show that

Structural organization of glycophorin A and B genes: Glycophorin B gene evolved by homologous recombination at Alu repeat sequences

International Nuclear Information System (INIS)

Kudo, Shinichi; Fukuda, Minoru

1989-01-01

Glycophorins A (GPA) and B (GPB) are two major sialoglycoproteins of the human erythrocyte membrane. Here the authors present a comparison of the genomic structures of GPA and GPB developed by analyzing DNA clones isolated from a K562 genomic library. Nucleotide sequences of exon-intron junctions and 5' and 3' flanking sequences revealed that the GPA and GPB genes consist of 7 and 5 exons, respectively, and both genes have >95% identical sequence from the 5' flanking region to the region ∼ 1 kilobase downstream from the exon encoding the transmembrane regions. In this homologous part of the genes, GPB lacks one exon due to a point mutation at the 5' splicing site of the third intron, which inactivates the 5' cleavage event of splicing and leads to ligation of the second to the fourth exon. Following these very homologous sequences, the genomic sequences for GPA and GPB diverge significantly and no homology can be detected in their 3' end sequences. The analysis of the Alu sequences and their flanking direct repeat sequences suggest that an ancestral genomic structure has been maintained in the GPA gene, whereas the GPB gene has arisen from the acquisition of 3' sequences different from those of the GPA gene by homologous recombination at the Alu repeats during or after gene duplication

Effect of cra gene knockout together with edd and iclR genes knockout on the metabolism in Escherichia coli.

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Sarkar, Dayanidhi; Siddiquee, Khandaker Al Zaid; Araúzo-Bravo, Marcos J; Oba, Takahiro; Shimizu, Kazuyuki

2008-11-01

To elucidate the physiological adaptation of Escherichia coli due to cra gene knockout, a total of 3,911 gene expressions were investigated by DNA microarray for continuous culture. About 50 genes were differentially regulated for the cra mutant. TCA cycle and glyoxylate shunt were down-regulated, while pentose phosphate (PP) pathway and Entner Doudoroff (ED) pathway were up-regulated in the cra mutant. The glucose uptake rate and the acetate production rate were increased with less acetate consumption for the cra mutant. To identify the genes controlled by Cra protein, the Cra recognition weight matrix from foot-printing data was developed and used to scan the whole genome. Several new Cra-binding sites were found, and some of the result was consistent with the DNA microarray data. The ED pathway was active in the cra mutant; we constructed cra.edd double genes knockout mutant to block this pathway, where the acetate overflowed due to the down-regulation of aceA,B and icd gene expressions. Then we further constructed cra.edd.iclR triple genes knockout mutant to direct the carbon flow through the glyoxylate pathway. The cra.edd.iclR mutant showed the least acetate production, resulting in the highest cell yield together with the activation of the glycolysis pathway, but the glucose consumption rate could not be improved.

Direct selection of expressed sequences on a YAC clone revealed proline-rich-like genes and BARE-1 sequences physically linked to the complex ¤Mla¤ powdery mildew resistance locus of barley (¤Hordeum vulgare¤ L.)

DEFF Research Database (Denmark)

Schwarz, G.; Michalek, W.; Jahoor, A.

2002-01-01

homology to the copia-like retroelement BA REI of barley, putatively involved in evolution of disease resistance loci. The high degree of clones representing barley rRNA sequences or false positives is a major disadvantage of direct selection of cDNAs in barley. (C) 2002 Elsevier Science Ireland Ltd. All...... gene. Of 22 selected cDNA clones, six were re-located on the YAC by southern analysis. Two of these clones are predicted to encode members of the hydroxyproline-rich glycoprotein and proline-rich protein gene families which have been implicated in plant defense response. Four sequences showed high...

Atypical DNA methylation of genes encoding cysteine-rich peptides in Arabidopsis thaliana

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You Wanhui

2012-04-01

Full Text Available Abstract Background In plants, transposons and non-protein-coding repeats are epigenetically silenced by CG and non-CG methylation. This pattern of methylation is mediated in part by small RNAs and two specialized RNA polymerases, termed Pol IV and Pol V, in a process called RNA-directed DNA methylation. By contrast, many protein-coding genes transcribed by Pol II contain in their gene bodies exclusively CG methylation that is independent of small RNAs and Pol IV/Pol V activities. It is unclear how the different methylation machineries distinguish between transposons and genes. Here we report on a group of atypical genes that display in their coding region a transposon-like methylation pattern, which is associated with gene silencing in sporophytic tissues. Results We performed a methylation-sensitive amplification polymorphism analysis to search for targets of RNA-directed DNA methylation in Arabidopsis thaliana and identified several members of a gene family encoding cysteine-rich peptides (CRPs. In leaves, the CRP genes are silent and their coding regions contain dense, transposon-like methylation in CG, CHG and CHH contexts, which depends partly on the Pol IV/Pol V pathway and small RNAs. Methylation in the coding region is reduced, however, in the synergid cells of the female gametophyte, where the CRP genes are specifically expressed. Further demonstrating that expressed CRP genes lack gene body methylation, a CRP4-GFP fusion gene under the control of the constitutive 35 S promoter remains unmethylated in leaves and is transcribed to produce a translatable mRNA. By contrast, a CRP4-GFP fusion gene under the control of a CRP4 promoter fragment acquires CG and non-CG methylation in the CRP coding region in leaves similar to the silent endogenous CRP4 gene. Conclusions Unlike CG methylation in gene bodies, which does not dramatically affect Pol II transcription, combined CG and non-CG methylation in CRP coding regions is likely to

Rapid changes in gene expression direct rapid shifts in intestinal form and function in the Burmese python after feeding.

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Andrew, Audra L; Card, Daren C; Ruggiero, Robert P; Schield, Drew R; Adams, Richard H; Pollock, David D; Secor, Stephen M; Castoe, Todd A

2015-05-01

Snakes provide a unique and valuable model system for studying the extremes of physiological remodeling because of the ability of some species to rapidly upregulate organ form and function upon feeding. The predominant model species used to study such extreme responses has been the Burmese python because of the extreme nature of postfeeding response in this species. We analyzed the Burmese python intestine across a time series, before, during, and after feeding to understand the patterns and timing of changes in gene expression and their relationship to changes in intestinal form and function upon feeding. Our results indicate that >2,000 genes show significant changes in expression in the small intestine following feeding, including genes involved in intestinal morphology and function (e.g., hydrolases, microvillus proteins, trafficking and transport proteins), as well as genes involved in cell division and apoptosis. Extensive changes in gene expression occur surprisingly rapidly, within the first 6 h of feeding, coincide with changes in intestinal morphology, and effectively return to prefeeding levels within 10 days. Collectively, our results provide an unprecedented portrait of parallel changes in gene expression and intestinal morphology and physiology on a scale that is extreme both in the magnitude of changes, as well as in the incredibly short time frame of these changes, with up- and downregulation of expression and function occurring in the span of 10 days. Our results also identify conserved vertebrate signaling pathways that modulate these responses, which may suggest pathways for therapeutic modulation of intestinal function in humans. Copyright © 2015 the American Physiological Society.

Direct visualization of electroporation-assisted in vivo gene delivery to tumors using intravital microscopy – spatial and time dependent distribution

International Nuclear Information System (INIS)

Cemazar, Maja; Wilson, Ian; Dachs, Gabi U; Tozer, Gillian M; Sersa, Gregor

2004-01-01

Electroporation is currently receiving much attention as a way to increase drug and DNA delivery. Recent studies demonstrated the feasibility of electrogene therapy using a range of therapeutic genes for the treatment of experimental tumors. However, the transfection efficiency of electroporation-assisted DNA delivery is still low compared to viral methods and there is a clear need to optimize this approach. In order to optimize treatment, knowledge about spatial and time dependency of gene expression following delivery is of utmost importance in order to improve gene delivery. Intravital microscopy of tumors growing in dorsal skin fold window chambers is a useful method for monitoring gene transfection, since it allows non-invasive dynamic monitoring of gene expression in tumors in a live animal. Intravital microscopy was used to monitor real time spatial distribution of the green fluorescent protein (GFP) and time dependence of transfection efficiency in syngeneic P22 rat tumor model. DNA alone, liposome-DNA complexes and electroporation-assisted DNA delivery using two different sets of electric pulse parameters were compared. Electroporation-assisted DNA delivery using 8 pulses, 600 V/cm, 5 ms, 1 Hz was superior to other methods and resulted in 22% increase in fluorescence intensity in the tumors up to 6 days post-transfection, compared to the non-transfected area in granulation tissue. Functional GFP was detected within 5 h after transfection. Cells expressing GFP were detected throughout the tumor, but not in the surrounding tissue that was not exposed to electric pulses. Intravital microscopy was demonstrated to be a suitable method for monitoring time and spatial distribution of gene expression in experimental tumors and provided evidence that electroporation-assisted gene delivery using 8 pulses, 600 V/cm, 5 ms, 1 Hz is an effective method, resulting in early onset and homogenous distribution of gene expression in the syngeneic P22 rat tumor model

Scuba: scalable kernel-based gene prioritization.

Science.gov (United States)

Zampieri, Guido; Tran, Dinh Van; Donini, Michele; Navarin, Nicolò; Aiolli, Fabio; Sperduti, Alessandro; Valle, Giorgio

2018-01-25

The uncovering of genes linked to human diseases is a pressing challenge in molecular biology and precision medicine. This task is often hindered by the large number of candidate genes and by the heterogeneity of the available information. Computational methods for the prioritization of candidate genes can help to cope with these problems. In particular, kernel-based methods are a powerful resource for the integration of heterogeneous biological knowledge, however, their practical implementation is often precluded by their limited scalability. We propose Scuba, a scalable kernel-based method for gene prioritization. It implements a novel multiple kernel learning approach, based on a semi-supervised perspective and on the optimization of the margin distribution. Scuba is optimized to cope with strongly unbalanced settings where known disease genes are few and large scale predictions are required. Importantly, it is able to efficiently deal both with a large amount of candidate genes and with an arbitrary number of data sources. As a direct consequence of scalability, Scuba integrates also a new efficient strategy to select optimal kernel parameters for each data source. We performed cross-validation experiments and simulated a realistic usage setting, showing that Scuba outperforms a wide range of state-of-the-art methods. Scuba achieves state-of-the-art performance and has enhanced scalability compared to existing kernel-based approaches for genomic data. This method can be useful to prioritize candidate genes, particularly when their number is large or when input data is highly heterogeneous. The code is freely available at https://github.com/gzampieri/Scuba .

Regulation of bacterial photosynthesis genes by the small noncoding RNA PcrZ.

Science.gov (United States)

Mank, Nils N; Berghoff, Bork A; Hermanns, Yannick N; Klug, Gabriele

2012-10-02

The small RNA PcrZ (photosynthesis control RNA Z) of the facultative phototrophic bacterium Rhodobacter sphaeroides is induced upon a drop of oxygen tension with similar kinetics to those of genes for components of photosynthetic complexes. High expression of PcrZ depends on PrrA, the response regulator of the PrrB/PrrA two-component system with a central role in redox regulation in R. sphaeroides. In addition the FnrL protein, an activator of some photosynthesis genes at low oxygen tension, is involved in redox-dependent expression of this small (s)RNA. Overexpression of full-length PcrZ in R. sphaeroides affects expression of a small subset of genes, most of them with a function in photosynthesis. Some mRNAs from the photosynthetic gene cluster were predicted to be putative PcrZ targets and results from an in vivo reporter system support these predictions. Our data reveal a negative effect of PcrZ on expression of its target mRNAs. Thus, PcrZ counteracts the redox-dependent induction of photosynthesis genes, which is mediated by protein regulators. Because PrrA directly activates photosynthesis genes and at the same time PcrZ, which negatively affects photosynthesis gene expression, this is one of the rare cases of an incoherent feed-forward loop including an sRNA. Our data identified PcrZ as a trans acting sRNA with a direct regulatory function in formation of photosynthetic complexes and provide a model for the control of photosynthesis gene expression by a regulatory network consisting of proteins and a small noncoding RNA.

Gene specific actions of thyroid hormone receptor subtypes.

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Jean Z Lin

Full Text Available There are two homologous thyroid hormone (TH receptors (TRs α and β, which are members of the nuclear hormone receptor (NR family. While TRs regulate different processes in vivo and other highly related NRs regulate distinct gene sets, initial studies of TR action revealed near complete overlaps in their actions at the level of individual genes. Here, we assessed the extent that TRα and TRβ differ in target gene regulation by comparing effects of equal levels of stably expressed exogenous TRs +/- T(3 in two cell backgrounds (HepG2 and HeLa. We find that hundreds of genes respond to T(3 or to unliganded TRs in both cell types, but were not able to detect verifiable examples of completely TR subtype-specific gene regulation. TR actions are, however, far from identical and we detect TR subtype-specific effects on global T(3 response kinetics in HepG2 cells and many examples of TR subtype specificity at the level of individual genes, including effects on magnitude of response to TR +/- T(3, TR regulation patterns and T(3 dose response. Cycloheximide (CHX treatment confirms that at least some differential effects involve verifiable direct TR target genes. TR subtype/gene-specific effects emerge in the context of widespread variation in target gene response and we suggest that gene-selective effects on mechanism of TR action highlight differences in TR subtype function that emerge in the environment of specific genes. We propose that differential TR actions could influence physiologic and pharmacologic responses to THs and selective TR modulators (STRMs.

Identification of a Divided Genome for VSH-1, the Prophage-Like Gene Transfer Agent of Brachyspira hyodysenteriae

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The Brachyspira hyodysenteriae B204 genome sequence revealed three VSH-1 tail genes hvp31, hvp60, and hvp37, in a 3.6 kb cluster. The location and transcription direction of these genes relative to the previously described VSH-1 16.3 kb gene operon indicate that the gene transfer agent VSH-1 has a ...

Direct identification of antibiotic resistance genes on single plasmid molecules using CRISPR/Cas9 in combination with optical DNA mapping

Science.gov (United States)

Müller, Vilhelm; Rajer, Fredrika; Frykholm, Karolin; Nyberg, Lena K.; Quaderi, Saair; Fritzsche, Joachim; Kristiansson, Erik; Ambjörnsson, Tobias; Sandegren, Linus; Westerlund, Fredrik

2016-12-01

Bacterial plasmids are extensively involved in the rapid global spread of antibiotic resistance. We here present an assay, based on optical DNA mapping of single plasmids in nanofluidic channels, which provides detailed information about the plasmids present in a bacterial isolate. In a single experiment, we obtain the number of different plasmids in the sample, the size of each plasmid, an optical barcode that can be used to identify and trace the plasmid of interest and information about which plasmid that carries a specific resistance gene. Gene identification is done using CRISPR/Cas9 loaded with a guide-RNA (gRNA) complementary to the gene of interest that linearizes the circular plasmids at a specific location that is identified using the optical DNA maps. We demonstrate the principle on clinically relevant extended spectrum beta-lactamase (ESBL) producing isolates. We discuss how the gRNA sequence can be varied to obtain the desired information. The gRNA can either be very specific to identify a homogeneous group of genes or general to detect several groups of genes at the same time. Finally, we demonstrate an example where we use a combination of two gRNA sequences to identify carbapenemase-encoding genes in two previously not characterized clinical bacterial samples.

Inference of gene regulatory networks with sparse structural equation models exploiting genetic perturbations.

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Xiaodong Cai

Full Text Available Integrating genetic perturbations with gene expression data not only improves accuracy of regulatory network topology inference, but also enables learning of causal regulatory relations between genes. Although a number of methods have been developed to integrate both types of data, the desiderata of efficient and powerful algorithms still remains. In this paper, sparse structural equation models (SEMs are employed to integrate both gene expression data and cis-expression quantitative trait loci (cis-eQTL, for modeling gene regulatory networks in accordance with biological evidence about genes regulating or being regulated by a small number of genes. A systematic inference method named sparsity-aware maximum likelihood (SML is developed for SEM estimation. Using simulated directed acyclic or cyclic networks, the SML performance is compared with that of two state-of-the-art algorithms: the adaptive Lasso (AL based scheme, and the QTL-directed dependency graph (QDG method. Computer simulations demonstrate that the novel SML algorithm offers significantly better performance than the AL-based and QDG algorithms across all sample sizes from 100 to 1,000, in terms of detection power and false discovery rate, in all the cases tested that include acyclic or cyclic networks of 10, 30 and 300 genes. The SML method is further applied to infer a network of 39 human genes that are related to the immune function and are chosen to have a reliable eQTL per gene. The resulting network consists of 9 genes and 13 edges. Most of the edges represent interactions reasonably expected from experimental evidence, while the remaining may just indicate the emergence of new interactions. The sparse SEM and efficient SML algorithm provide an effective means of exploiting both gene expression and perturbation data to infer gene regulatory networks. An open-source computer program implementing the SML algorithm is freely available upon request.

Identification of putative noncoding RNA genes in the Burkholderia cenocepacia J2315 genome

DEFF Research Database (Denmark)

Coenye, T.; Drevinek, P.; Mahenthiralingam, E.

2007-01-01

Noncoding RNA (ncRNA) genes are not involved in the production of mRNA and proteins, but produce transcripts that function directly as structural or regulatory RNAs. In the present study, the presence of ncRNA genes in the genome of Burkholderia cenocepacia J2315 was evaluated by combining...

Gene-expression signatures of Atlantic salmon’s plastic life cycle

Science.gov (United States)

Aubin-Horth, Nadia; Letcher, Benjamin H.; Hofmann, Hans A.

2009-01-01

How genomic expression differs as a function of life history variation is largely unknown. Atlantic salmon exhibits extreme alternative life histories. We defined the gene-expression signatures of wild-caught salmon at two different life stages by comparing the brain expression profiles of mature sneaker males and immature males, and early migrants and late migrants. In addition to life-stage-specific signatures, we discovered a surprisingly large gene set that was differentially regulated - at similar magnitudes, yet in opposite direction - in both life history transitions. We suggest that this co-variation is not a consequence of many independent cellular and molecular switches in the same direction but rather represents the molecular equivalent of a physiological shift orchestrated by one or very few master regulators. PMID:19401203

Self-focusing therapeutic gene delivery with intelligent gene vector swarms: intra-swarm signalling through receptor transgene expression in targeted cells.

Science.gov (United States)

Tolmachov, Oleg E

2015-01-01

Gene delivery in vivo that is tightly focused on the intended target cells is essential to maximize the benefits of gene therapy and to reduce unwanted side-effects. Cell surface markers are immediately available for probing by therapeutic gene vectors and are often used to direct gene transfer with these vectors to specific target cell populations. However, it is not unusual for the choice of available extra-cellular markers to be too scarce to provide a reliable definition of the desired therapeutically relevant set of target cells. Therefore, interrogation of intra-cellular determinants of cell-specificity, such as tissue-specific transcription factors, can be vital in order to provide detailed cell-guiding information to gene vector particles. An important improvement in cell-specific gene delivery can be achieved through auto-buildup in vector homing efficiency using intelligent 'self-focusing' of swarms of vector particles on target cells. Vector self-focusing was previously suggested to rely on the release of diffusible chemo-attractants after a successful target-specific hit by 'scout' vector particles. I hypothesize that intelligent self-focusing behaviour of swarms of cell-targeted therapeutic gene vectors can be accomplished without the employment of difficult-to-use diffusible chemo-attractants, instead relying on the intra-swarm signalling through cells expressing a non-diffusible extra-cellular receptor for the gene vectors. In the proposed model, cell-guiding information is gathered by the 'scout' gene vector particles, which: (1) attach to a variety of cells via a weakly binding (low affinity) receptor; (2) successfully facilitate gene transfer into these cells; (3) query intra-cellular determinants of cell-specificity with their transgene expression control elements and (4) direct the cell-specific biosynthesis of a vector-encoded strongly binding (high affinity) cell-surface receptor. Free members of the vector swarm loaded with therapeutic cargo

Brain gene expression changes elicited by peripheral vitellogenin knockdown in the honey bee.

Science.gov (United States)

Wheeler, M M; Ament, S A; Rodriguez-Zas, S L; Robinson, G E

2013-10-01

Vitellogenin (Vg) is best known as a yolk protein precursor. Vg also functions to regulate behavioural maturation in adult honey bee workers, but the underlying molecular mechanisms by which it exerts this novel effect are largely unknown. We used abdominal vitellogenin (vg) knockdown with RNA interference (RNAi) and brain transcriptomic profiling to gain insights into how Vg influences honey bee behavioural maturation. We found that vg knockdown caused extensive gene expression changes in the bee brain, with much of this transcriptional response involving changes in central biological functions such as energy metabolism. vg knockdown targeted many of the same genes that show natural, maturation-related differences, but the direction of change for the genes in these two contrasts was not correlated. By contrast, vg knockdown targeted many of the same genes that are regulated by juvenile hormone (JH) and there was a significant correlation for the direction of change for the genes in these two contrasts. These results indicate that the tight coregulatory relationship that exists between JH and Vg in the regulation of honey bee behavioural maturation is manifest at the genomic level and suggest that these two physiological factors act through common pathways to regulate brain gene expression and behaviour. © 2013 Royal Entomological Society.

Gene copy number variation throughout the Plasmodium falciparum genome

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Stewart Lindsay B

2009-08-01

Full Text Available Abstract Background Gene copy number variation (CNV is responsible for several important phenotypes of the malaria parasite Plasmodium falciparum, including drug resistance, loss of infected erythrocyte cytoadherence and alteration of receptor usage for erythrocyte invasion. Despite the known effects of CNV, little is known about its extent throughout the genome. Results We performed a whole-genome survey of CNV genes in P. falciparum using comparative genome hybridisation of a diverse set of 16 laboratory culture-adapted isolates to a custom designed high density Affymetrix GeneChip array. Overall, 186 genes showed hybridisation signals consistent with deletion or amplification in one or more isolate. There is a strong association of CNV with gene length, genomic location, and low orthology to genes in other Plasmodium species. Sub-telomeric regions of all chromosomes are strongly associated with CNV genes independent from members of previously described multigene families. However, ~40% of CNV genes were located in more central regions of the chromosomes. Among the previously undescribed CNV genes, several that are of potential phenotypic relevance are identified. Conclusion CNV represents a major form of genetic variation within the P. falciparum genome; the distribution of gene features indicates the involvement of highly non-random mutational and selective processes. Additional studies should be directed at examining CNV in natural parasite populations to extend conclusions to clinical settings.

Predictability of Genetic Interactions from Functional Gene Modules

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Jonathan H. Young

2017-02-01

Full Text Available Characterizing genetic interactions is crucial to understanding cellular and organismal response to gene-level perturbations. Such knowledge can inform the selection of candidate disease therapy targets, yet experimentally determining whether genes interact is technically nontrivial and time-consuming. High-fidelity prediction of different classes of genetic interactions in multiple organisms would substantially alleviate this experimental burden. Under the hypothesis that functionally related genes tend to share common genetic interaction partners, we evaluate a computational approach to predict genetic interactions in Homo sapiens, Drosophila melanogaster, and Saccharomyces cerevisiae. By leveraging knowledge of functional relationships between genes, we cross-validate predictions on known genetic interactions and observe high predictive power of multiple classes of genetic interactions in all three organisms. Additionally, our method suggests high-confidence candidate interaction pairs that can be directly experimentally tested. A web application is provided for users to query genes for predicted novel genetic interaction partners. Finally, by subsampling the known yeast genetic interaction network, we found that novel genetic interactions are predictable even when knowledge of currently known interactions is minimal.

Gene discovery by chemical mutagenesis and whole-genome sequencing in Dictyostelium.

Science.gov (United States)

Li, Cheng-Lin Frank; Santhanam, Balaji; Webb, Amanda Nicole; Zupan, Blaž; Shaulsky, Gad

2016-09-01

Whole-genome sequencing is a useful approach for identification of chemical-induced lesions, but previous applications involved tedious genetic mapping to pinpoint the causative mutations. We propose that saturation mutagenesis under low mutagenic loads, followed by whole-genome sequencing, should allow direct implication of genes by identifying multiple independent alleles of each relevant gene. We tested the hypothesis by performing three genetic screens with chemical mutagenesis in the social soil amoeba Dictyostelium discoideum Through genome sequencing, we successfully identified mutant genes with multiple alleles in near-saturation screens, including resistance to intense illumination and strong suppressors of defects in an allorecognition pathway. We tested the causality of the mutations by comparison to published data and by direct complementation tests, finding both dominant and recessive causative mutations. Therefore, our strategy provides a cost- and time-efficient approach to gene discovery by integrating chemical mutagenesis and whole-genome sequencing. The method should be applicable to many microbial systems, and it is expected to revolutionize the field of functional genomics in Dictyostelium by greatly expanding the mutation spectrum relative to other common mutagenesis methods. © 2016 Li et al.; Published by Cold Spring Harbor Laboratory Press.

Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells.

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Kaitsuka, Taku; Tomizawa, Kazuhito

2015-11-06

Protein transduction using cell-penetrating peptides (CPPs) is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS) cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies.

Cell-Penetrating Peptide as a Means of Directing the Differentiation of Induced-Pluripotent Stem Cells

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Taku Kaitsuka

2015-11-01

Full Text Available Protein transduction using cell-penetrating peptides (CPPs is useful for the delivery of large protein molecules, including some transcription factors. This method is safer than gene transfection methods with a viral vector because there is no risk of genomic integration of the exogenous DNA. Recently, this method was reported as a means for the induction of induced pluripotent stem (iPS cells, directing the differentiation into specific cell types and supporting gene editing/correction. Furthermore, we developed a direct differentiation method to obtain a pancreatic lineage from mouse and human pluripotent stem cells via the protein transduction of three transcription factors, Pdx1, NeuroD, and MafA. Here, we discuss the possibility of using CPPs as a means of directing the differentiation of iPS cells and other stem cell technologies.

Gene screening in a Chinese family with Marfan syndrome

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Wen-Jiao Xia

2016-05-01

Full Text Available AIM:To analyze the causative gene mutation for Marfan syndrome(MFSwith autosomal dominant hereditary in a Chinese family in Liaoning Province,China. METHODS: Venous blood was collected and candidate gene was selected to design primers according to the clinical phenotype. With genomic polymerase chain reaction(PCRperformed, the coding exons and their flanking intron in sequences of candidate gene were sequenced,DNA fragments separated by agarose gel electrophoresis and direct sequencing method was used to determine the pathogenic gene.RESULTS:Phenotype of the proband was presented as ectopic lentis. Sequencing of the coding regions of FBN1 gene showed the presence of a heterozygous A→G transversion at nucleotide 640 in the 7 exon of FBN1 and the missense mutation made for Glycine into Serine(G214S. CONCLUSION:A heterozygous mutation of FBN1 c.A640G(p.G214Sis responsible for the Marfan syndrome in the four generation Chinese pedigree.

Scaling proprioceptor gene transcription by retrograde NT3 signaling.

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Jun Lee

Full Text Available Cell-type specific intrinsic programs instruct neuronal subpopulations before target-derived factors influence later neuronal maturation. Retrograde neurotrophin signaling controls neuronal survival and maturation of dorsal root ganglion (DRG sensory neurons, but how these potent signaling pathways intersect with transcriptional programs established at earlier developmental stages remains poorly understood. Here we determine the consequences of genetic alternation of NT3 signaling on genome-wide transcription programs in proprioceptors, an important sensory neuron subpopulation involved in motor reflex behavior. We find that the expression of many proprioceptor-enriched genes is dramatically altered by genetic NT3 elimination, independent of survival-related activities. Combinatorial analysis of gene expression profiles with proprioceptors isolated from mice expressing surplus muscular NT3 identifies an anticorrelated gene set with transcriptional levels scaled in opposite directions. Voluntary running experiments in adult mice further demonstrate the maintenance of transcriptional adjustability of genes expressed by DRG neurons, pointing to life-long gene expression plasticity in sensory neurons.

Brains, Genes and Primates

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Belmonte, Juan Carlos Izpisua; Callaway, Edward M.; Churchland, Patricia; Caddick, Sarah J.; Feng, Guoping; Homanics, Gregg E.; Lee, Kuo-Fen; Leopold, David A.; Miller, Cory T.; Mitchell, Jude F.; Mitalipov, Shoukhrat; Moutri, Alysson R.; Movshon, J. Anthony; Okano, Hideyuki; Reynolds, John H.; Ringach, Dario; Sejnowski, Terrence J.; Silva, Afonso C.; Strick, Peter L.; Wu, Jun; Zhang, Feng

2015-01-01

One of the great strengths of the mouse model is the wide array of genetic tools that have been developed. Striking examples include methods for directed modification of the genome, and for regulated expression or inactivation of genes. Within neuroscience, it is now routine to express reporter genes, neuronal activity indicators and opsins in specific neuronal types in the mouse. However, there are considerable anatomical, physiological, cognitive and behavioral differences between the mouse and the human that, in some areas of inquiry, limit the degree to which insights derived from the mouse can be applied to understanding human neurobiology. Several recent advances have now brought into reach the goal of applying these tools to understanding the primate brain. Here we describe these advances, consider their potential to advance our understanding of the human brain and brain disorders, discuss bioethical considerations, and describe what will be needed to move forward. PMID:25950631

The potential for tumor suppressor gene therapy in head and neck cancer.

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Birkeland, Andrew C; Ludwig, Megan L; Spector, Matthew E; Brenner, J Chad

2016-01-01

Head and neck squamous cell carcinoma remains a highly morbid and fatal disease. Importantly, genomic sequencing of head and neck cancers has identified frequent mutations in tumor suppressor genes. While targeted therapeutics increasingly are being investigated in head and neck cancer, the majority of these agents are against overactive/overexpressed oncogenes. Therapy to restore lost tumor suppressor gene function remains a key and under-addressed niche in trials for head and neck cancer. Recent advances in gene editing have captured the interest of both the scientific community and the public. As our technology for gene editing and gene expression modulation improves, addressing lost tumor suppressor gene function in head and neck cancers is becoming a reality. This review will summarize new techniques, challenges to implementation, future directions, and ethical ramifications of gene therapy in head and neck cancer.

Homologous Recombination-Independent Large Gene Cassette Knock-in in CHO Cells Using TALEN and MMEJ-Directed Donor Plasmids

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Tetsushi Sakuma

2015-10-01

Full Text Available Gene knock-in techniques have rapidly evolved in recent years, along with the development and maturation of genome editing technology using programmable nucleases. We recently reported a novel strategy for microhomology-mediated end-joining-dependent integration of donor DNA by using TALEN or CRISPR/Cas9 and optimized targeting vectors, named PITCh (Precise Integration into Target Chromosome vectors. Here we describe TALEN and PITCh vector-mediated integration of long gene cassettes, including a single-chain Fv-Fc (scFv-Fc gene, in Chinese hamster ovary (CHO cells, with comparison of targeting and cloning efficiency among several donor design and culture conditions. We achieved 9.6-kb whole plasmid integration and 7.6-kb backbone-free integration into a defined genomic locus in CHO cells. Furthermore, we confirmed the reasonable productivity of recombinant scFv-Fc protein of the knock-in cells. Using our protocol, the knock-in cell clones could be obtained by a single transfection and a single limiting dilution using a 96-well plate, without constructing targeting vectors containing long homology arms. Thus, the study described herein provides a highly practical strategy for gene knock-in of large DNA in CHO cells, which accelerates high-throughput generation of cell lines stably producing any desired biopharmaceuticals, including huge antibody proteins.

Homologous Recombination-Independent Large Gene Cassette Knock-in in CHO Cells Using TALEN and MMEJ-Directed Donor Plasmids.

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Sakuma, Tetsushi; Takenaga, Mitsumasa; Kawabe, Yoshinori; Nakamura, Takahiro; Kamihira, Masamichi; Yamamoto, Takashi

2015-10-09

Gene knock-in techniques have rapidly evolved in recent years, along with the development and maturation of genome editing technology using programmable nucleases. We recently reported a novel strategy for microhomology-mediated end-joining-dependent integration of donor DNA by using TALEN or CRISPR/Cas9 and optimized targeting vectors, named PITCh (Precise Integration into Target Chromosome) vectors. Here we describe TALEN and PITCh vector-mediated integration of long gene cassettes, including a single-chain Fv-Fc (scFv-Fc) gene, in Chinese hamster ovary (CHO) cells, with comparison of targeting and cloning efficiency among several donor design and culture conditions. We achieved 9.6-kb whole plasmid integration and 7.6-kb backbone-free integration into a defined genomic locus in CHO cells. Furthermore, we confirmed the reasonable productivity of recombinant scFv-Fc protein of the knock-in cells. Using our protocol, the knock-in cell clones could be obtained by a single transfection and a single limiting dilution using a 96-well plate, without constructing targeting vectors containing long homology arms. Thus, the study described herein provides a highly practical strategy for gene knock-in of large DNA in CHO cells, which accelerates high-throughput generation of cell lines stably producing any desired biopharmaceuticals, including huge antibody proteins.

Imaging gene expression in gene therapy

International Nuclear Information System (INIS)

Wiebe, Leonard I.

1997-01-01

Full text. Gene therapy can be used to introduce new genes, or to supplement the function of indigenous genes. At the present time, however, there is non-invasive test to demonstrate efficacy of the gene transfer and expression processes. It has been postulated that scintigraphic imaging can offer unique information on both the site at which the transferred gene is expressed, and the degree of expression, both of which are critical issue for safety and clinical efficacy. Many current studies are based on 'suicide gene therapy' of cancer. Cells modified to express these genes commit metabolic suicide in the presence of an enzyme encoded by the transferred gene and a specifically-convertible pro drug. Pro drug metabolism can lead to selective metabolic trapping, required for scintigraphy. Herpes simplex virus type-1 thymidine kinase (H S V-1 t k + ) has been use for 'suicide' in vivo tumor gene therapy. It has been proposed that radiolabelled nucleosides can be used as radiopharmaceuticals to detect H S V-1 t k + gene expression where the H S V-1 t k + gene serves a reporter or therapeutic function. Animal gene therapy models have been studied using purine-([ 18 F]F H P G; [ 18 F]-A C V), and pyrimidine- ([ 123 / 131 I]I V R F U; [ 124 / 131I ]) antiviral nucleosides. Principles of gene therapy and gene therapy imaging will be reviewed and experimental data for [ 123 / 131I ]I V R F U imaging with the H S V-1 t k + reporter gene will be presented

Direct activation of human and mouse Oct4 genes using engineered TALE and Cas9 transcription factors.

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Hu, Jiabiao; Lei, Yong; Wong, Wing-Ki; Liu, Senquan; Lee, Kai-Chuen; He, Xiangjun; You, Wenxing; Zhou, Rui; Guo, Jun-Tao; Chen, Xiongfong; Peng, Xianlu; Sun, Hao; Huang, He; Zhao, Hui; Feng, Bo

2014-04-01

The newly developed transcription activator-like effector protein (TALE) and clustered regularly interspaced short palindromic repeats/Cas9 transcription factors (TF) offered a powerful and precise approach for modulating gene expression. In this article, we systematically investigated the potential of these new tools in activating the stringently silenced pluripotency gene Oct4 (Pou5f1) in mouse and human somatic cells. First, with a number of TALEs and sgRNAs targeting various regions in the mouse and human Oct4 promoters, we found that the most efficient TALE-VP64s bound around -120 to -80 bp, while highly effective sgRNAs targeted from -147 to -89-bp upstream of the transcription start sites to induce high activity of luciferase reporters. In addition, we observed significant transcriptional synergy when multiple TFs were applied simultaneously. Although individual TFs exhibited marginal activity to up-regulate endogenous gene expression, optimized combinations of TALE-VP64s could enhance endogenous Oct4 transcription up to 30-fold in mouse NIH3T3 cells and 20-fold in human HEK293T cells. More importantly, the enhancement of OCT4 transcription ultimately generated OCT4 proteins. Furthermore, examination of different epigenetic modifiers showed that histone acetyltransferase p300 could enhance both TALE-VP64 and sgRNA/dCas9-VP64 induced transcription of endogenous OCT4. Taken together, our study suggested that engineered TALE-TF and dCas9-TF are useful tools for modulating gene expression in mammalian cells.

Characteristic differences between the promoters of intron-containing and intronless ribosomal protein genes in yeast

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Vingron Martin

2008-10-01

Full Text Available Abstract Background More than two thirds of the highly expressed ribosomal protein (RP genes in Saccharomyces cerevisiae contain introns, which is in sharp contrast to the genome-wide five percent intron-containing genes. It is well established that introns carry regulatory sequences and that the transcription of RP genes is extensively and coordinately regulated. Here we test the hypotheses that introns are innately associated with heavily transcribed genes and that introns of RP genes contribute regulatory TF binding sequences. Moreover, we investigate whether promoter features are significantly different between intron-containing and intronless RP genes. Results We find that directly measured transcription rates tend to be lower for intron-containing compared to intronless RP genes. We do not observe any specifically enriched sequence motifs in the introns of RP genes other than those of the branch point and the two splice sites. Comparing the promoters of intron-containing and intronless RP genes, we detect differences in number and position of Rap1-binding and IFHL motifs. Moreover, the analysis of the length distribution and the folding free energies suggest that, at least in a sub-population of RP genes, the 5' untranslated sequences are optimized for regulatory function. Conclusion Our results argue against the direct involvement of introns in the regulation of transcription of highly expressed genes. Moreover, systematic differences in motif distributions suggest that RP transcription factors may act differently on intron-containing and intronless gene promoters. Thus, our findings contribute to the decoding of the RP promoter architecture and may fuel the discussion on the evolution of introns.

Characteristics and Validation Techniques for PCA-Based Gene-Expression Signatures

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Anders E. Berglund

2017-01-01

Full Text Available Background. Many gene-expression signatures exist for describing the biological state of profiled tumors. Principal Component Analysis (PCA can be used to summarize a gene signature into a single score. Our hypothesis is that gene signatures can be validated when applied to new datasets, using inherent properties of PCA. Results. This validation is based on four key concepts. Coherence: elements of a gene signature should be correlated beyond chance. Uniqueness: the general direction of the data being examined can drive most of the observed signal. Robustness: if a gene signature is designed to measure a single biological effect, then this signal should be sufficiently strong and distinct compared to other signals within the signature. Transferability: the derived PCA gene signature score should describe the same biology in the target dataset as it does in the training dataset. Conclusions. The proposed validation procedure ensures that PCA-based gene signatures perform as expected when applied to datasets other than those that the signatures were trained upon. Complex signatures, describing multiple independent biological components, are also easily identified.

An integrative approach to inferring biologically meaningful gene modules

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Wang Kai

2011-07-01

Full Text Available Abstract Background The ability to construct biologically meaningful gene networks and modules is critical for contemporary systems biology. Though recent studies have demonstrated the power of using gene modules to shed light on the functioning of complex biological systems, most modules in these networks have shown little association with meaningful biological function. We have devised a method which directly incorporates gene ontology (GO annotation in construction of gene modules in order to gain better functional association. Results We have devised a method, Semantic Similarity-Integrated approach for Modularization (SSIM that integrates various gene-gene pairwise similarity values, including information obtained from gene expression, protein-protein interactions and GO annotations, in the construction of modules using affinity propagation clustering. We demonstrated the performance of the proposed method using data from two complex biological responses: 1. the osmotic shock response in Saccharomyces cerevisiae, and 2. the prion-induced pathogenic mouse model. In comparison with two previously reported algorithms, modules identified by SSIM showed significantly stronger association with biological functions. Conclusions The incorporation of semantic similarity based on GO annotation with gene expression and protein-protein interaction data can greatly enhance the functional relevance of inferred gene modules. In addition, the SSIM approach can also reveal the hierarchical structure of gene modules to gain a broader functional view of the biological system. Hence, the proposed method can facilitate comprehensive and in-depth analysis of high throughput experimental data at the gene network level.

Sexy sons: a dead end for cytoplasmic genes.

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Zeh, Jeanne A

2004-08-07

Critics of sexual conflict theory argue that females may gain a net reproductive benefit from mating with manipulative males because the direct costs that they suffer may be offset by the production of sexy, i.e. manipulative, sons. However, this exclusive focus on nuclear gene effects represents an incomplete view of female fitness. Females differ fundamentally from males in transmitting not only nuclear genes but also a wide range of cytoplasmic genetic elements (CGEs) that can have profound effects, from male killing to influencing development of the nervous system and cognitive ability. Maternal transmission of CGEs has two major implications for sexual selection. First, the evolution of male fitness traits, such as sperm competitive ability, may be constrained because response to selection on mitochondrial genomes can occur only through the female line. Second, CGEs bear the direct costs of male manipulation but gain no indirect benefits when females produce sexy sons. This should result in perpetual antagonistic coevolution between nuclear genes involved in male manipulation and CGEs that promote female resistance to male sexually selected traits. Explicit consideration of the consequences of selection acting on CGEs is therefore necessary for a better understanding of the relationship between sexual selection and sexual conflict.

Identification of the gene for Nance-Horan syndrome (NHS).

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Brooks, S P; Ebenezer, N D; Poopalasundaram, S; Lehmann, O J; Moore, A T; Hardcastle, A J

2004-10-01

The disease intervals for Nance-Horan syndrome (NHS [MIM 302350]) and X linked congenital cataract (CXN) overlap on Xp22. To identify the gene or genes responsible for these diseases. Families with NHS were ascertained. The refined locus for CXN was used to focus the search for candidate genes, which were screened by polymerase chain reaction and direct sequencing of potential exons and intron-exon splice sites. Genomic structures and homologies were determined using bioinformatics. Expression studies were undertaken using specific exonic primers to amplify human fetal cDNA and mouse RNA. A novel gene NHS, with no known function, was identified as causative for NHS. Protein truncating mutations were detected in all three NHS pedigrees, but no mutation was identified in a CXN family, raising the possibility that NHS and CXN may not be allelic. The NHS gene forms a new gene family with a closely related novel gene NHS-Like1 (NHSL1). NHS and NHSL1 lie in paralogous duplicated chromosomal intervals on Xp22 and 6q24, and NHSL1 is more broadly expressed than NHS in human fetal tissues. This study reports the independent identification of the gene causative for Nance-Horan syndrome and extends the number of mutations identified.

Direct visualization of electroporation-assisted in vivo gene delivery to tumors using intravital microscopy – spatial and time dependent distribution

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Dachs Gabi U

2004-11-01

Full Text Available Abstract Background Electroporation is currently receiving much attention as a way to increase drug and DNA delivery. Recent studies demonstrated the feasibility of electrogene therapy using a range of therapeutic genes for the treatment of experimental tumors. However, the transfection efficiency of electroporation-assisted DNA delivery is still low compared to viral methods and there is a clear need to optimize this approach. In order to optimize treatment, knowledge about spatial and time dependency of gene expression following delivery is of utmost importance in order to improve gene delivery. Intravital microscopy of tumors growing in dorsal skin fold window chambers is a useful method for monitoring gene transfection, since it allows non-invasive dynamic monitoring of gene expression in tumors in a live animal. Methods Intravital microscopy was used to monitor real time spatial distribution of the green fluorescent protein (GFP and time dependence of transfection efficiency in syngeneic P22 rat tumor model. DNA alone, liposome-DNA complexes and electroporation-assisted DNA delivery using two different sets of electric pulse parameters were compared. Results Electroporation-assisted DNA delivery using 8 pulses, 600 V/cm, 5 ms, 1 Hz was superior to other methods and resulted in 22% increase in fluorescence intensity in the tumors up to 6 days post-transfection, compared to the non-transfected area in granulation tissue. Functional GFP was detected within 5 h after transfection. Cells expressing GFP were detected throughout the tumor, but not in the surrounding tissue that was not exposed to electric pulses. Conclusions Intravital microscopy was demonstrated to be a suitable method for monitoring time and spatial distribution of gene expression in experimental tumors and provided evidence that electroporation-assisted gene delivery using 8 pulses, 600 V/cm, 5 ms, 1 Hz is an effective method, resulting in early onset and homogenous

Feasibility of sodium/iodide symporter gene as a new imaging reporter gene: comparison with HSV1-tk

International Nuclear Information System (INIS)

Shin, Jae Hoon; Chung, June-Key; Lee, Yong Jin; Kim, Kwang Il; Kang, Joo Hyun; Jeong, Jae Min; Lee, Dong Soo; Kim, Chul Woo; Lee, Myung Chul

2004-01-01

Positron emission tomography (PET) imaging reporter genes, such as HSV1-tk and D 2 receptor genes, make it possible to visualise gene expression non-invasively and repetitively in vivo. However, these systems require the synthesis of complicated substrates and the availability of expensive PET equipment. Expression of the sodium/iodide symporter (NIS) gene can be easily monitored with radioiodines and technetium-99m using a gamma camera. To evaluate the possibility of using NIS as an imaging reporter gene, we compared its characteristics with those of the conventional HSV1-tk gene. The CM cell line was made by transfecting the HSV1-tk gene into CT-26 (mouse colon carcinoma cell line). The CTN and CMN cell lines were then made by transfecting the NIS gene into CT-26 and CM. We measured the uptake of iodine-125 iodovinyldeoxyuridine ([ 125 I]IVDU) and 125 I to evaluate the expression of the HSV1-tk and NIS genes, respectively. Each cell line was injected into four flank sites in Balb/c mice. The biodistribution study was performed after intravenously injecting [ 125 I]IVDU and 131 I, and 131 I scintigraphy was performed for the evaluation of NIS expression. In vitro studies indicated that CTN and CMN had 40- to 79-fold and 150- to 256-fold higher uptake of 125 I than CT-26 and CM, respectively. Furthermore, CM and CMN showed 57- to 69-fold higher uptake of [ 125 I]IVDU than CT-26 and CTN. NIS gene expression and 125 I accumulation were found to be directly correlated (R 2 =0.923), as were HSV1-tk gene expression and [ 125 I]IVDU accumulation (R 2 =0.956). Calculated signal per unit NIS and HSV1-tk mRNA expression was 23,240±3,755 cpm and 34,039±5,346 cpm, respectively. In vivo study indicated that CTN and CMN had 2.3- and 5.8-fold higher uptake of 131 I than CT-26 and CM, and 1.8- and 3.5-fold higher uptake of [ 125 I]IVDU than CT-26 and CTN. Scintigraphy using 131 I easily visualised CTN and CMN tumours. In conclusion, the NIS gene may be viewed as an imaging

Mining biological databases for candidate disease genes

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Braun, Terry A.; Scheetz, Todd; Webster, Gregg L.; Casavant, Thomas L.

2001-07-01

The publicly-funded effort to sequence the complete nucleotide sequence of the human genome, the Human Genome Project (HGP), has currently produced more than 93% of the 3 billion nucleotides of the human genome into a preliminary `draft' format. In addition, several valuable sources of information have been developed as direct and indirect results of the HGP. These include the sequencing of model organisms (rat, mouse, fly, and others), gene discovery projects (ESTs and full-length), and new technologies such as expression analysis and resources (micro-arrays or gene chips). These resources are invaluable for the researchers identifying the functional genes of the genome that transcribe and translate into the transcriptome and proteome, both of which potentially contain orders of magnitude more complexity than the genome itself. Preliminary analyses of this data identified approximately 30,000 - 40,000 human `genes.' However, the bulk of the effort still remains -- to identify the functional and structural elements contained within the transcriptome and proteome, and to associate function in the transcriptome and proteome to genes. A fortuitous consequence of the HGP is the existence of hundreds of databases containing biological information that may contain relevant data pertaining to the identification of disease-causing genes. The task of mining these databases for information on candidate genes is a commercial application of enormous potential. We are developing a system to acquire and mine data from specific databases to aid our efforts to identify disease genes. A high speed cluster of Linux of workstations is used to analyze sequence and perform distributed sequence alignments as part of our data mining and processing. This system has been used to mine GeneMap99 sequences within specific genomic intervals to identify potential candidate disease genes associated with Bardet-Biedle Syndrome (BBS).

Molecular characterization of a fungal gene paralogue of the penicillin penDE gene of Penicillium chrysogenum

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2009-01-01

Background Penicillium chrysogenum converts isopenicillin N (IPN) into hydrophobic penicillins by means of the peroxisomal IPN acyltransferase (IAT), which is encoded by the penDE gene. In silico analysis of the P. chrysogenum genome revealed the presence of a gene, Pc13g09140, initially described as paralogue of the IAT-encoding penDE gene. We have termed this gene ial because it encodes a protein with high similarity to IAT (IAL for IAT-Like). We have conducted an investigation to characterize the ial gene and to determine the role of the IAL protein in the penicillin biosynthetic pathway. Results The IAL contains motifs characteristic of the IAT such as the processing site, but lacks the peroxisomal targeting sequence ARL. Null ial mutants and overexpressing strains indicated that IAL lacks acyltransferase (penicillin biosynthetic) and amidohydrolase (6-APA forming) activities in vivo. When the canonical ARL motif (leading to peroxisomal targeting) was added to the C-terminus of the IAL protein (IALARL) by site-directed mutagenesis, no penicillin biosynthetic activity was detected. Since the IAT is only active after an accurate self-processing of the preprotein into α and β subunits, self-processing of the IAL was tested in Escherichia coli. Overexpression experiments and SDS-PAGE analysis revealed that IAL is also self-processed in two subunits, but despite the correct processing, the enzyme remained inactive in vitro. Conclusion No activity related to the penicillin biosynthesis was detected for the IAL. Sequence comparison among the P. chrysogenum IAL, the A. nidulans IAL homologue and the IAT, revealed that the lack of enzyme activity seems to be due to an alteration of the essential Ser309 in the thioesterase active site. Homologues of the ial gene have been found in many other ascomycetes, including non-penicillin producers. Our data suggest that like in A. nidulans, the ial and penDE genes might have been formed from a single ancestral gene that became

Imaging gene expression in gene therapy

Energy Technology Data Exchange (ETDEWEB)

Wiebe, Leonard I. [Alberta Univ., Edmonton (Canada). Noujaim Institute for Pharmaceutical Oncology Research

1997-12-31

Full text. Gene therapy can be used to introduce new genes, or to supplement the function of indigenous genes. At the present time, however, there is non-invasive test to demonstrate efficacy of the gene transfer and expression processes. It has been postulated that scintigraphic imaging can offer unique information on both the site at which the transferred gene is expressed, and the degree of expression, both of which are critical issue for safety and clinical efficacy. Many current studies are based on `suicide gene therapy` of cancer. Cells modified to express these genes commit metabolic suicide in the presence of an enzyme encoded by the transferred gene and a specifically-convertible pro drug. Pro drug metabolism can lead to selective metabolic trapping, required for scintigraphy. Herpes simplex virus type-1 thymidine kinase (H S V-1 t k{sup +}) has been use for `suicide` in vivo tumor gene therapy. It has been proposed that radiolabelled nucleosides can be used as radiopharmaceuticals to detect H S V-1 t k{sup +} gene expression where the H S V-1 t k{sup +} gene serves a reporter or therapeutic function. Animal gene therapy models have been studied using purine-([{sup 18} F]F H P G; [{sup 18} F]-A C V), and pyrimidine- ([{sup 123}/{sup 131} I]I V R F U; [{sup 124}/{sup 131I}]) antiviral nucleosides. Principles of gene therapy and gene therapy imaging will be reviewed and experimental data for [{sup 123}/{sup 131I}]I V R F U imaging with the H S V-1 t k{sup +} reporter gene will be presented

Comparing the DNA hypermethylome with gene mutations in human colorectal cancer.

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Kornel E Schuebel

2007-09-01

Full Text Available We have developed a transcriptome-wide approach to identify genes affected by promoter CpG island DNA hypermethylation and transcriptional silencing in colorectal cancer. By screening cell lines and validating tumor-specific hypermethylation in a panel of primary human colorectal cancer samples, we estimate that nearly 5% or more of all known genes may be promoter methylated in an individual tumor. When directly compared to gene mutations, we find larger numbers of genes hypermethylated in individual tumors, and a higher frequency of hypermethylation within individual genes harboring either genetic or epigenetic changes. Thus, to enumerate the full spectrum of alterations in the human cancer genome, and to facilitate the most efficacious grouping of tumors to identify cancer biomarkers and tailor therapeutic approaches, both genetic and epigenetic screens should be undertaken.

Stem cell and gene therapies for diabetes mellitus.

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Calne, Roy Y; Gan, Shu Uin; Lee, Kok Onn

2010-03-01

In this Perspectives article, we comment on the progress in experimental stem cell and gene therapies that might one day become a clinical reality for the treatment of patients with diabetes mellitus. Research on the ability of human embryonic stem cells to differentiate into islet cells has defined the developmental stages and transcription factors involved in this process. However, the clinical applications of human embryonic stem cells are limited by ethical concerns, as well as the potential for teratoma formation. As a consequence, alternative forms of stem cell therapies, such as induced pluripotent stem cells and bone marrow-derived mesenchymal stem cells, have become an area of intense study. Finally, gene therapy shows some promise for the generation of insulin-producing cells. Here, we discuss two of the most frequently used approaches: in vitro gene delivery into cells which are then transplanted into the recipient and direct delivery of genes in vivo.

Reconstruction of ribosomal RNA genes from metagenomic data.

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Lu Fan

Full Text Available Direct sequencing of environmental DNA (metagenomics has a great potential for describing the 16S rRNA gene diversity of microbial communities. However current approaches using this 16S rRNA gene information to describe community diversity suffer from low taxonomic resolution or chimera problems. Here we describe a new strategy that involves stringent assembly and data filtering to reconstruct full-length 16S rRNA genes from metagenomicpyrosequencing data. Simulations showed that reconstructed 16S rRNA genes provided a true picture of the community diversity, had minimal rates of chimera formation and gave taxonomic resolution down to genus level. The strategy was furthermore compared to PCR-based methods to determine the microbial diversity in two marine sponges. This showed that about 30% of the abundant phylotypes reconstructed from metagenomic data failed to be amplified by PCR. Our approach is readily applicable to existing metagenomic datasets and is expected to lead to the discovery of new microbial phylotypes.

Root parasitic plant Orobanche aegyptiaca and shoot parasitic plant Cuscuta australis obtained Brassicaceae-specific strictosidine synthase-like genes by horizontal gene transfer.

Science.gov (United States)

Zhang, Dale; Qi, Jinfeng; Yue, Jipei; Huang, Jinling; Sun, Ting; Li, Suoping; Wen, Jian-Fan; Hettenhausen, Christian; Wu, Jinsong; Wang, Lei; Zhuang, Huifu; Wu, Jianqiang; Sun, Guiling

2014-01-13

Besides gene duplication and de novo gene generation, horizontal gene transfer (HGT) is another important way of acquiring new genes. HGT may endow the recipients with novel phenotypic traits that are important for species evolution and adaption to new ecological niches. Parasitic systems expectedly allow the occurrence of HGT at relatively high frequencies due to their long-term physical contact. In plants, a number of HGT events have been reported between the organelles of parasites and the hosts, but HGT between host and parasite nuclear genomes has rarely been found. A thorough transcriptome screening revealed that a strictosidine synthase-like (SSL) gene in the root parasitic plant Orobanche aegyptiaca and the shoot parasitic plant Cuscuta australis showed much higher sequence similarities with those in Brassicaceae than with those in their close relatives, suggesting independent gene horizontal transfer events from Brassicaceae to these parasites. These findings were strongly supported by phylogenetic analysis and their identical unique amino acid residues and deletions. Intriguingly, the nucleus-located SSL genes in Brassicaceae belonged to a new member of SSL gene family, which were originated from gene duplication. The presence of introns indicated that the transfer occurred directly by DNA integration in both parasites. Furthermore, positive selection was detected in the foreign SSL gene in O. aegyptiaca but not in C. australis. The expression of the foreign SSL genes in these two parasitic plants was detected in multiple development stages and tissues, and the foreign SSL gene was induced after wounding treatment in C. australis stems. These data imply that the foreign genes may still retain certain functions in the recipient species. Our study strongly supports that parasitic plants can gain novel nuclear genes from distantly related host species by HGT and the foreign genes may execute certain functions in the new hosts.

Monitoring single-cell gene regulation under dynamically controllable conditions with integrated microfluidics and software

NARCIS (Netherlands)

Kaiser, Matthias; Jug, Florian; Julou, Thomas; Deshpande, S.R.; Pfohl, Thomas; Silander, Olin K.; Myers, Gene; Van Nimwegen, Erik

2018-01-01

Much is still not understood about how gene regulatory interactions control cell fate decisions in single cells, in part due to the difficulty of directly observing gene regulatory processes in vivo. We introduce here a novel integrated setup consisting of a microfluidic chip and accompanying

Loss of Sfpq Causes Long-Gene Transcriptopathy in the Brain

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Akihide Takeuchi

2018-05-01

Full Text Available Summary: Genes specifically expressed in neurons contain members with extended long introns. Longer genes present a problem with respect to fulfilment of gene length transcription, and evidence suggests that dysregulation of long genes is a mechanism underlying neurodegenerative and psychiatric disorders. Here, we report the discovery that RNA-binding protein Sfpq is a critical factor for maintaining transcriptional elongation of long genes. We demonstrate that Sfpq co-transcriptionally binds to long introns and is required for sustaining long-gene transcription by RNA polymerase II through mediating the interaction of cyclin-dependent kinase 9 with the elongation complex. Phenotypically, Sfpq disruption caused neuronal apoptosis in developing mouse brains. Expression analysis of Sfpq-regulated genes revealed specific downregulation of developmentally essential neuronal genes longer than 100 kb in Sfpq-disrupted brains; those genes are enriched in associations with neurodegenerative and psychiatric diseases. The identified molecular machinery yields directions for targeted investigations of the association between long-gene transcriptopathy and neuronal diseases. : It has been a long-standing question how mammalian neuronal cells achieve full gene length transcription of extra-long genes. Takeuchi et al. show that RNA-binding protein Sfpq sustains long-gene transcription through Pol II-CTD activation. Loss of Sfpq caused long-gene transcriptopathy, which could be the cause of neurodegenerative and psychiatric disorders. Keywords: RNA-binding protein, transcriptional regulation, RNA polymerase II, cyclin-dependent kinase 9, RBP/transcript-dependent elongation, long-gene transcriptotherapy, neuronal development, neurological and psychiatric diseases, long-gene diseases, long genopathies

Ribosomal protein gene knockdown causes developmental defects in zebrafish.

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Tamayo Uechi

Full Text Available The ribosomal proteins (RPs form the majority of cellular proteins and are mandatory for cellular growth. RP genes have been linked, either directly or indirectly, to various diseases in humans. Mutations in RP genes are also associated with tissue-specific phenotypes, suggesting a possible role in organ development during early embryogenesis. However, it is not yet known how mutations in a particular RP gene result in specific cellular changes, or how RP genes might contribute to human diseases. The development of animal models with defects in RP genes will be essential for studying these questions. In this study, we knocked down 21 RP genes in zebrafish by using morpholino antisense oligos to inhibit their translation. Of these 21, knockdown of 19 RPs resulted in the development of morphants with obvious deformities. Although mutations in RP genes, like other housekeeping genes, would be expected to result in nonspecific developmental defects with widespread phenotypes, we found that knockdown of some RP genes resulted in phenotypes specific to each gene, with varying degrees of abnormality in the brain, body trunk, eyes, and ears at about 25 hours post fertilization. We focused further on the organogenesis of the brain. Each knocked-down gene that affected the morphogenesis of the brain produced a different pattern of abnormality. Among the 7 RP genes whose knockdown produced severe brain phenotypes, 3 human orthologs are located within chromosomal regions that have been linked to brain-associated diseases, suggesting a possible involvement of RP genes in brain or neurological diseases. The RP gene knockdown system developed in this study could be a powerful tool for studying the roles of ribosomes in human diseases.

The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit

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Vincent, Maxence S.; Durand, Eric; Cascales, Eric

2016-01-01

The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS. PMID:27630829

WD-repeat instability and diversification of the Podospora anserina hnwd non-self recognition gene family.

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Chevanne, Damien; Saupe, Sven J; Clavé, Corinne; Paoletti, Mathieu

2010-05-06

Genes involved in non-self recognition and host defence are typically capable of rapid diversification and exploit specialized genetic mechanism to that end. Fungi display a non-self recognition phenomenon termed heterokaryon incompatibility that operates when cells of unlike genotype fuse and leads to the cell death of the fusion cell. In the fungus Podospora anserina, three genes controlling this allorecognition process het-d, het-e and het-r are paralogs belonging to the same hnwd gene family. HNWD proteins are STAND proteins (signal transduction NTPase with multiple domains) that display a WD-repeat domain controlling recognition specificity. Based on genomic sequence analysis of different P. anserina isolates, it was established that repeat regions of all members of the gene family are extremely polymorphic and undergoing concerted evolution arguing for frequent recombination within and between family members. Herein, we directly analyzed the genetic instability and diversification of this allorecognition gene family. We have constituted a collection of 143 spontaneous mutants of the het-R (HNWD2) and het-E (hnwd5) genes with altered recognition specificities. The vast majority of the mutants present rearrangements in the repeat arrays with deletions, duplications and other modifications as well as creation of novel repeat unit variants. We investigate the extreme genetic instability of these genes and provide a direct illustration of the diversification strategy of this eukaryotic allorecognition gene family.

A 44 bp intestine-specific hermaphrodite-specific enhancer from the C. elegans vit-2 vitellogenin gene is directly regulated by ELT-2, MAB-3, FKH-9 and DAF-16 and indirectly regulated by the germline, by daf-2/insulin signaling and by the TGF-β/Sma/Mab pathway.

Science.gov (United States)

Goszczynski, Barbara; Captan, Vasile V; Danielson, Alicia M; Lancaster, Brett R; McGhee, James D

2016-05-01

The Caenorhabditis elegans vitellogenin genes are transcribed in the intestine of adult hermaphrodites but not of males. A 44-bp region from the vit-2 gene promoter is able largely to reconstitute this tissue-, stage- and sex-specific-expression. This "enhancer" contains a binding site for the DM-domain factor MAB-3, the male-specific repressor of vitellogenesis, as well as an activator site that we show is the direct target of the intestinal GATA factor ELT-2. We further show that the enhancer is directly activated by the winged-helix/forkhead-factor FKH-9, (whose gene has been shown by others to be a direct target of DAF-16), by an unknown activator binding to the MAB-3 site, and by the full C. elegans TGF-β/Sma/Mab pathway acting within the intestine. The vit-2 gene has been shown by others to be repressed by the daf-2/daf-16 insulin signaling pathway, which so strongly influences aging and longevity in C. elegans. We show that the activity of the 44 bp vit-2 enhancer is abolished by loss of daf-2 but is restored by simultaneous loss of daf-16. DAF-2 acts from outside of the intestine but DAF-16 acts both from outside of the intestine and from within the intestine where it binds directly to the same non-canonical target site that interacts with FKH-9. Activity of the 44 bp vit-2 enhancer is also inhibited by loss of the germline, in a manner that is only weakly influenced by DAF-16 but that is strongly influenced by KRI-1, a key downstream effector in the pathway by which germline loss increases C. elegans lifespan. The complex behavior of this enhancer presumably allows vitellogenin gene transcription to adjust to demands of body size, germline proliferation and nutritional state but we suggest that the apparent involvement of this enhancer in aging and longevity "pathways" could be incidental. Copyright © 2016 Elsevier Inc. All rights reserved.

A family with hereditary hemochromatosis carrying HFE gene splice site mutation: a case report

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NING Huibin

2017-01-01

Full Text Available ObjectiveTo investigate a new type of HFE gene mutation in a family with hereditary hemochromatosis (HH. MethodsThe analysis of HFE gene was performed for one patient with a confirmed diagnosis of HH and five relatives. Blood genomic DNA was extracted and PCR multiplication was performed for the exon and intron splice sequences of related HFE, HJV, HAMP, transferrin receptor 2 (TfR2, and SLC40A1 genes. After agarose gel electrophoresis and purification, bi-directional direct sequencing was performed to detect mutation sites. ResultsThe proband had abnormal liver function and increases in serum iron, total iron binding capacity, serum ferritin, and transferrin saturation, as well as T→C homozygous mutation in the fourth base of intron 2 in the intervening sequence of the exon EXON2 of HFE gene (IVs 2+4T→C, C/C homozygous, splicing, abnormal. There were no abnormalities in HJV, HAMP, TfR2, and SLC40A1 genes. The proband′s son had the same homozygous mutation, three relatives had heterozygous mutations, and one relative had no abnormal mutations. ConclusionGene detection plays an important role in the diagnosis of hemochromatosis, and IVs 2+4T→C mutation may be a new pathogenic mutation for HH in China.

Role of Endothelial Nitric Oxide Synthase Gene Polymorphisms ...

African Journals Online (AJOL)

maintenance of pregnancy, but it is rather controversial whether polymorphisms of the gene encoding for eNOS are associated ... specific human leukocyte antigen alleles that seem to be ... prevents the contractions of the uterine myometrium directly or by an ... an anatomical factor, to avoid this possible bias all candidates.

Subclinical hyperthyroidism due to a thyrotropin receptor (TSHR) gene mutation (S505R).

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Pohlenz, Joachim; Pfarr, Nicole; Krüger, Silvia; Hesse, Volker

2006-12-01

To identify the molecular defect by which non-autoimmune subclinical hyperthyroidism was caused in a 6-mo-old infant who presented with weight loss. Congenital non-autoimmune hyperthyroidism is caused by activating germline mutations in the thyrotropin receptor (TSHR) gene. Therefore, the TSHR gene was sequenced directly from the patient's genomic DNA. Molecular analysis revealed a heterozygous point mutation (S505R) in the TSHR gene as the underlying defect. A constitutively activating mutation in the TSHR gene has to be considered not only in patients with severe congenital non-autoimmune hyperthyroidism, but also in children with subclinical non-autoimmune hyperthyroidism.

Differentially expressed genes in iron-induced prion protein conversion

International Nuclear Information System (INIS)

Kim, Minsun; Kim, Eun-hee; Choi, Bo-Ran; Woo, Hee-Jong

2016-01-01

The conversion of the cellular prion protein (PrP C ) to the protease-resistant isoform is the key event in chronic neurodegenerative diseases, including transmissible spongiform encephalopathies (TSEs). Increased iron in prion-related disease has been observed due to the prion protein-ferritin complex. Additionally, the accumulation and conversion of recombinant PrP (rPrP) is specifically derived from Fe(III) but not Fe(II). Fe(III)-mediated PK-resistant PrP (PrP res ) conversion occurs within a complex cellular environment rather than via direct contact between rPrP and Fe(III). In this study, differentially expressed genes correlated with prion degeneration by Fe(III) were identified using Affymetrix microarrays. Following Fe(III) treatment, 97 genes were differentially expressed, including 85 upregulated genes and 12 downregulated genes (≥1.5-fold change in expression). However, Fe(II) treatment produced moderate alterations in gene expression without inducing dramatic alterations in gene expression profiles. Moreover, functional grouping of identified genes indicated that the differentially regulated genes were highly associated with cell growth, cell maintenance, and intra- and extracellular transport. These findings showed that Fe(III) may influence the expression of genes involved in PrP folding by redox mechanisms. The identification of genes with altered expression patterns in neural cells may provide insights into PrP conversion mechanisms during the development and progression of prion-related diseases. - Highlights: • Differential genes correlated with prion degeneration by Fe(III) were identified. • Genes were identified in cell proliferation and intra- and extracellular transport. • In PrP degeneration, redox related genes were suggested. • Cbr2, Rsad2, Slc40a1, Amph and Mvd were expressed significantly.

A comparison of digital gene expression profiling and methyl DNA immunoprecipitation as methods for gene discovery in honeybee (Apis mellifera behavioural genomic analyses.

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Cui Guan

Full Text Available The honey bee has a well-organized system of division of labour among workers. Workers typically progress through a series of discrete behavioural castes as they age, and this has become an important case study for exploring how dynamic changes in gene expression can influence behaviour. Here we applied both digital gene expression analysis and methyl DNA immunoprecipitation analysis to nurse, forager and reverted nurse bees (nurses that have returned to the nursing state after a period spent foraging from the same colony in order to compare the outcomes of these different forms of genomic analysis. A total of 874 and 710 significantly differentially expressed genes were identified in forager/nurse and reverted nurse/forager comparisons respectively. Of these, 229 genes exhibited reversed directions of gene expression differences between the forager/nurse and reverted nurse/forager comparisons. Using methyl-DNA immunoprecipitation combined with high-throughput sequencing (MeDIP-seq we identified 366 and 442 significantly differentially methylated genes in forager/nurse and reverted nurse/forager comparisons respectively. Of these, 165 genes were identified as differentially methylated in both comparisons. However, very few genes were identified as both differentially expressed and differentially methylated in our comparisons of nurses and foragers. These findings confirm that changes in both gene expression and DNA methylation are involved in the nurse and forager behavioural castes, but the different analytical methods reveal quite distinct sets of candidate genes.

Directional and balancing selection in human beta-defensins.

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Hollox, Edward J; Armour, John A L

2008-04-16

In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93), is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

Rapid directed evolution of stabilized proteins with cellular high-throughput encapsulation solubilization and screening (CHESS).

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Yong, K J; Scott, D J

2015-03-01

Directed evolution is a powerful method for engineering proteins towards user-defined goals and has been used to generate novel proteins for industrial processes, biological research and drug discovery. Typical directed evolution techniques include cellular display, phage display, ribosome display and water-in-oil compartmentalization, all of which physically link individual members of diverse gene libraries to their translated proteins. This allows the screening or selection for a desired protein function and subsequent isolation of the encoding gene from diverse populations. For biotechnological and industrial applications there is a need to engineer proteins that are functional under conditions that are not compatible with these techniques, such as high temperatures and harsh detergents. Cellular High-throughput Encapsulation Solubilization and Screening (CHESS), is a directed evolution method originally developed to engineer detergent-stable G proteins-coupled receptors (GPCRs) for structural biology. With CHESS, library-transformed bacterial cells are encapsulated in detergent-resistant polymers to form capsules, which serve to contain mutant genes and their encoded proteins upon detergent mediated solubilization of cell membranes. Populations of capsules can be screened like single cells to enable rapid isolation of genes encoding detergent-stable protein mutants. To demonstrate the general applicability of CHESS to other proteins, we have characterized the stability and permeability of CHESS microcapsules and employed CHESS to generate thermostable, sodium dodecyl sulfate (SDS) resistant green fluorescent protein (GFP) mutants, the first soluble proteins to be engineered using CHESS. © 2014 Wiley Periodicals, Inc.

A genomic perspective on protein tyrosine phosphatases: gene structure, pseudogenes, and genetic disease linkage

DEFF Research Database (Denmark)

Andersen, Jannik N; Jansen, Peter G; Echwald, Søren M

2004-01-01

sequence databases, we discovered one novel human PTP gene and defined chromosomal loci and exon structure of the additional 37 genes encoding known PTP transcripts. Direct orthologs were present in the mouse genome for all 38 human PTP genes. In addition, we identified 12 PTP pseudogenes unique to humans...... that have probably contaminated previous bioinformatics analysis of this gene family. PCR amplification and transcript sequencing indicate that some PTP pseudogenes are expressed, but their function (if any) is unknown. Furthermore, we analyzed the enhanced diversity generated by alternative splicing...

Insights into the Functions of a Prophage Recombination Directionality Factor

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Mireille Ansaldi

2012-10-01

Full Text Available Recombination directionality factors (RDFs, or excisionases, are essential players of prophage excisive recombination. Despite the essentially catalytic role of the integrase in both integrative and excisive recombination, RDFs are required to direct the reaction towards excision and to prevent re-integration of the prophage genome when entering a lytic cycle. KplE1, HK620 and numerous (prophages that integrate at the same site in enterobacteria genomes (such as the argW tRNA gene all share a highly conserved recombination module. This module comprises the attL and attR recombination sites and the RDF and integrase genes. The KplE1 RDF was named TorI after its initial identification as a negative regulator of the tor operon. However, it was characterized as an essential factor of excisive recombination. In this study, we designed an extensive random mutagenesis protocol of the torI gene and identified key residues involved in both functions of the TorI protein. We show that, in addition to TorI-TorR protein-protein interaction, TorI interacts in solution with the IntS integrase. Moreover, in vitro, TorR and IntS appear to compete for TorI binding. Finally, our mutagenesis results suggest that the C-terminal part of the TorI protein is dedicated to protein-protein interactions with both proteins TorR and IntS.

Erythropoietin abuse and erythropoietin gene doping: detection strategies in the genomic era.

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Diamanti-Kandarakis, Evanthia; Konstantinopoulos, Panagiotis A; Papailiou, Joanna; Kandarakis, Stylianos A; Andreopoulos, Anastasios; Sykiotis, Gerasimos P

2005-01-01

The administration of recombinant human erythropoietin (rhEPO) increases the maximum oxygen consumption capacity, and is therefore abused as a doping method in endurance sports. The detection of erythropoietin (EPO) abuse is based on direct pharmacological and indirect haematological approaches, both of which have several limitations. In addition, current detection methods cannot cope with the emerging doping strategies of EPO mimicry, analogues and gene doping, and thus novel detection strategies are urgently needed. Direct detection methods for EPO misuse can be either pharmacological approaches that identify exogenous substances based on their physicochemical properties, or molecular methods that recognise EPO transgenes or gene transfer vectors. Since direct detection with molecular methods requires invasive procedures, it is not appropriate for routine screening of large numbers of athletes. In contrast, novel indirect methods based on haematological and/or molecular profiling could be better suited as screening tools, and athletes who are suspect of doping would then be submitted to direct pharmacological and molecular tests. This article reviews the current state of the EPO doping field, discusses available detection methods and their shortcomings, outlines emerging pharmaceutical and genetic technologies in EPO misuse, and proposes potential directions for the development of novel detection strategies.

Protein phosphatase 2ACα gene knock-out results in cortical atrophy through activating hippo cascade in neuronal progenitor cells.

Science.gov (United States)

Liu, Bo; Sun, Li-Hua; Huang, Yan-Fei; Guo, Li-Jun; Luo, Li-Shu

2018-02-01

Protein phosphatase 2ACα (PP2ACα), a vital member of the protein phosphatase family, has been studied primarily as a regulator for the development, growth and protein synthesis of a lot of cell types. Dysfunction of PP2ACα protein results in neurodegenerative disease; however, this finding has not been directly confirmed in the mouse model with PP2ACα gene knock-out. Therefore, in this study presented here, we generated the PP2ACα gene knock-out mouse model by the Cre-loxP targeting gene system, with the purpose to directly observe the regulatory role of PP2ACα gene in the development of mouse's cerebral cortex. We observe that knocking-out PP2ACα gene in the central nervous system (CNS) results in cortical neuronal shrinkage, synaptic plasticity impairments, and learning/memory deficits. Further study reveals that PP2ACα gene knock-out initiates Hippo cascade in cortical neuroprogenitor cells (NPCs), which blocks YAP translocation into the nuclei of NPCs. Notably, p73, directly targeted by Hippo cascade, can bind to the promoter of glutaminase2 (GLS2) that plays a dominant role in the enzymatic regulation of glutamate/glutamine cycle. Finally, we find that PP2ACα gene knock-out inhibits the glutamine synthesis through up-regulating the activity of phosphorylated-p73 in cortical NPCs. Taken together, it concludes that PP2ACα critically supports cortical neuronal growth and cognitive function via regulating the signaling transduction of Hippo-p73 cascade. And PP2ACα indirectly modulates the glutamine synthesis of cortical NPCs through targeting p73 that plays a direct transcriptional regulatory role in the gene expression of GLS2. Copyright © 2017 Elsevier Ltd. All rights reserved.

Large gene overlaps in prokaryotic genomes: result of functional constraints or mispredictions?

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Harrington Eoghan D

2008-07-01

Full Text Available Abstract Background Across the fully sequenced microbial genomes there are thousands of examples of overlapping genes. Many of these are only a few nucleotides long and are thought to function by permitting the coordinated regulation of gene expression. However, there should also be selective pressure against long overlaps, as the existence of overlapping reading frames increases the risk of deleterious mutations. Here we examine the longest overlaps and assess whether they are the product of special functional constraints or of erroneous annotation. Results We analysed the genes that overlap by 60 bps or more among 338 fully-sequenced prokaryotic genomes. The likely functional significance of an overlap was determined by comparing each of the genes to its respective orthologs. If a gene showed a significantly different length from its orthologs it was considered unlikely to be functional and therefore the result of an error either in sequencing or gene prediction. Focusing on 715 co-directional overlaps longer than 60 bps, we classified the erroneous ones into five categories: i 5'-end extension of the downstream gene due to either a mispredicted start codon or a frameshift at 5'-end of the gene (409 overlaps, ii fragmentation of a gene caused by a frameshift (163, iii 3'-end extension of the upstream gene due to either a frameshift at 3'-end of a gene or point mutation at the stop codon (68, iv Redundant gene predictions (4, v 5' & 3'-end extension which is a combination of i and iii (71. We also studied 75 divergent overlaps that could be classified as misannotations of group i. Nevertheless we found some convergent long overlaps (54 that might be true overlaps, although an important part of convergent overlaps could be classified as group iii (124. Conclusion Among the 968 overlaps larger than 60 bps which we analysed, we did not find a single real one among the co-directional and divergent orientations and concluded that there had been an

Conditions for gene disruption by homologous recombination of exogenous DNA into the Sulfolobus solfataricus genome

NARCIS (Netherlands)

Albers, Sonja-Verena; Driessen, Arnold J.M.

2008-01-01

The construction of directed gene deletion mutants is an essential tool in molecular biology that allows functional studies on the role of genes in their natural environment. For hyperthermophilic archaea, it has been difficult to obtain a reliable system to construct such mutants. However, during

Targeted gene therapy and cell reprogramming in Fanconi anemia

Science.gov (United States)

Rio, Paula; Baños, Rocio; Lombardo, Angelo; Quintana-Bustamante, Oscar; Alvarez, Lara; Garate, Zita; Genovese, Pietro; Almarza, Elena; Valeri, Antonio; Díez, Begoña; Navarro, Susana; Torres, Yaima; Trujillo, Juan P; Murillas, Rodolfo; Segovia, Jose C; Samper, Enrique; Surralles, Jordi; Gregory, Philip D; Holmes, Michael C; Naldini, Luigi; Bueren, Juan A

2014-01-01

Gene targeting is progressively becoming a realistic therapeutic alternative in clinics. It is unknown, however, whether this technology will be suitable for the treatment of DNA repair deficiency syndromes such as Fanconi anemia (FA), with defects in homology-directed DNA repair. In this study, we used zinc finger nucleases and integrase-defective lentiviral vectors to demonstrate for the first time that FANCA can be efficiently and specifically targeted into the AAVS1 safe harbor locus in fibroblasts from FA-A patients. Strikingly, up to 40% of FA fibroblasts showed gene targeting 42 days after gene editing. Given the low number of hematopoietic precursors in the bone marrow of FA patients, gene-edited FA fibroblasts were then reprogrammed and re-differentiated toward the hematopoietic lineage. Analyses of gene-edited FA-iPSCs confirmed the specific integration of FANCA in the AAVS1 locus in all tested clones. Moreover, the hematopoietic differentiation of these iPSCs efficiently generated disease-free hematopoietic progenitors. Taken together, our results demonstrate for the first time the feasibility of correcting the phenotype of a DNA repair deficiency syndrome using gene-targeting and cell reprogramming strategies. PMID:24859981

Pathogenomic inference of virulence-associated genes in Leptospira interrogans.

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Lehmann, Jason S; Fouts, Derrick E; Haft, Daniel H; Cannella, Anthony P; Ricaldi, Jessica N; Brinkac, Lauren; Harkins, Derek; Durkin, Scott; Sanka, Ravi; Sutton, Granger; Moreno, Angelo; Vinetz, Joseph M; Matthias, Michael A

2013-01-01

Leptospirosis is a globally important, neglected zoonotic infection caused by spirochetes of the genus Leptospira. Since genetic transformation remains technically limited for pathogenic Leptospira, a systems biology pathogenomic approach was used to infer leptospiral virulence genes by whole genome comparison of culture-attenuated Leptospira interrogans serovar Lai with its virulent, isogenic parent. Among the 11 pathogen-specific protein-coding genes in which non-synonymous mutations were found, a putative soluble adenylate cyclase with host cell cAMP-elevating activity, and two members of a previously unstudied ∼15 member paralogous gene family of unknown function were identified. This gene family was also uniquely found in the alpha-proteobacteria Bartonella bacilliformis and Bartonella australis that are geographically restricted to the Andes and Australia, respectively. How the pathogenic Leptospira and these two Bartonella species came to share this expanded gene family remains an evolutionary mystery. In vivo expression analyses demonstrated up-regulation of 10/11 Leptospira genes identified in the attenuation screen, and profound in vivo, tissue-specific up-regulation by members of the paralogous gene family, suggesting a direct role in virulence and host-pathogen interactions. The pathogenomic experimental design here is generalizable as a functional systems biology approach to studying bacterial pathogenesis and virulence and should encourage similar experimental studies of other pathogens.

Duchenne Muscular Dystrophy Gene Therapy in the Canine Model

Science.gov (United States)

2015-01-01

Abstract Duchenne muscular dystrophy (DMD) is an X-linked lethal muscle disease caused by dystrophin deficiency. Gene therapy has significantly improved the outcome of dystrophin-deficient mice. Yet, clinical translation has not resulted in the expected benefits in human patients. This translational gap is largely because of the insufficient modeling of DMD in mice. Specifically, mice lacking dystrophin show minimum dystrophic symptoms, and they do not respond to the gene therapy vector in the same way as human patients do. Further, the size of a mouse is hundredfolds smaller than a boy, making it impossible to scale-up gene therapy in a mouse model. None of these limitations exist in the canine DMD (cDMD) model. For this reason, cDMD dogs have been considered a highly valuable platform to test experimental DMD gene therapy. Over the last three decades, a variety of gene therapy approaches have been evaluated in cDMD dogs using a number of nonviral and viral vectors. These studies have provided critical insight for the development of an effective gene therapy protocol in human patients. This review discusses the history, current status, and future directions of the DMD gene therapy in the canine model. PMID:25710459

Progesterone Upregulates Gene Expression in Normal Human Thyroid Follicular Cells

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Ana Paula Santin Bertoni

2015-01-01

Full Text Available Thyroid cancer and thyroid nodules are more prevalent in women than men, so female sex hormones may have an etiological role in these conditions. There are no data about direct effects of progesterone on thyroid cells, so the aim of the present study was to evaluate progesterone effects in the sodium-iodide symporter NIS, thyroglobulin TG, thyroperoxidase TPO, and KI-67 genes expression, in normal thyroid follicular cells, derived from human tissue. NIS, TG, TPO, and KI-67 mRNA expression increased significantly after TSH 20 μUI/mL, respectively: 2.08 times, P<0.0001; 2.39 times, P=0.01; 1.58 times, P=0.0003; and 1.87 times, P<0.0001. In thyroid cells treated with 20 μUI/mL TSH plus 10 nM progesterone, RNA expression of NIS, TG, and KI-67 genes increased, respectively: 1.78 times, P<0.0001; 1.75 times, P=0.037; and 1.95 times, P<0.0001, and TPO mRNA expression also increased, though not significantly (1.77 times, P=0.069. These effects were abolished by mifepristone, an antagonist of progesterone receptor, suggesting that genes involved in thyroid cell function and proliferation are upregulated by progesterone. This work provides evidence that progesterone has a direct effect on thyroid cells, upregulating genes involved in thyroid function and growth.

Learning directed acyclic graphs from large-scale genomics data.

Science.gov (United States)

Nikolay, Fabio; Pesavento, Marius; Kritikos, George; Typas, Nassos

2017-09-20

In this paper, we consider the problem of learning the genetic interaction map, i.e., the topology of a directed acyclic graph (DAG) of genetic interactions from noisy double-knockout (DK) data. Based on a set of well-established biological interaction models, we detect and classify the interactions between genes. We propose a novel linear integer optimization program called the Genetic-Interactions-Detector (GENIE) to identify the complex biological dependencies among genes and to compute the DAG topology that matches the DK measurements best. Furthermore, we extend the GENIE program by incorporating genetic interaction profile (GI-profile) data to further enhance the detection performance. In addition, we propose a sequential scalability technique for large sets of genes under study, in order to provide statistically significant results for real measurement data. Finally, we show via numeric simulations that the GENIE program and the GI-profile data extended GENIE (GI-GENIE) program clearly outperform the conventional techniques and present real data results for our proposed sequential scalability technique.

Novel algorithms reveal streptococcal transcriptomes and clues about undefined genes.

Science.gov (United States)

Ryan, Patricia A; Kirk, Brian W; Euler, Chad W; Schuch, Raymond; Fischetti, Vincent A

2007-07-01

Bacteria-host interactions are dynamic processes, and understanding transcriptional responses that directly or indirectly regulate the expression of genes involved in initial infection stages would illuminate the molecular events that result in host colonization. We used oligonucleotide microarrays to monitor (in vitro) differential gene expression in group A streptococci during pharyngeal cell adherence, the first overt infection stage. We present neighbor clustering, a new computational method for further analyzing bacterial microarray data that combines two informative characteristics of bacterial genes that share common function or regulation: (1) similar gene expression profiles (i.e., co-expression); and (2) physical proximity of genes on the chromosome. This method identifies statistically significant clusters of co-expressed gene neighbors that potentially share common function or regulation by coupling statistically analyzed gene expression profiles with the chromosomal position of genes. We applied this method to our own data and to those of others, and we show that it identified a greater number of differentially expressed genes, facilitating the reconstruction of more multimeric proteins and complete metabolic pathways than would have been possible without its application. We assessed the biological significance of two identified genes by assaying deletion mutants for adherence in vitro and show that neighbor clustering indeed provides biologically relevant data. Neighbor clustering provides a more comprehensive view of the molecular responses of streptococci during pharyngeal cell adherence.

A Novel Nonviral Gene Delivery System: Multifunctional Envelope-Type Nano Device

Science.gov (United States)

Hatakeyama, Hiroto; Akita, Hidetaka; Kogure, Kentaro; Harashima, Hideyoshi

In this review we introduce a new concept for developing a nonviral gene delivery system which we call "Programmed Packaging." Based on this concept, we succeeded in developing a multifunctional envelope-type nano device (MEND), which exerts high transfection activities equivalent to those of an adenovirus in a dividing cell. The use of MEND has been extended to in vivo applications. PEG/peptide/DOPE ternary conjugate (PPD)-MEND, a new in vivo gene delivery system for the targeting of tumor cells that dissociates surface-modified PEG in tumor tissue by matrix metalloproteinase (MMP) and exerts significant transfection activities, was developed. In parallel with the development of MEND, a quantitative gene delivery system, Confocal Image-assisted 3-dimensionally integrated quantification (CIDIQ), also was developed. This method identified the rate-limiting step of the nonviral gene delivery system by comparing it with adenoviral-mediated gene delivery. The results of this analysis provide a new direction for the development of rational nonviral gene delivery systems.

Directed evolution induces tributyrin hydrolysis in a virulence factor of Xylella fastidiosa using a duplicated gene as a template [v1; ref status: indexed, http://f1000r.es/48i

Directory of Open Access Journals (Sweden)

Hossein Gouran

2014-09-01

Full Text Available Duplication of genes is one of the preferred ways for natural selection to add advantageous functionality to the genome without having to reinvent the wheel with respect to catalytic efficiency and protein stability. The duplicated secretory virulence factors of Xylella fastidiosa (LesA, LesB and LesC, implicated in Pierce's disease of grape and citrus variegated chlorosis of citrus species, epitomizes the positive selection pressures exerted on advantageous genes in such pathogens. A deeper insight into the evolution of these lipases/esterases is essential to develop resistance mechanisms in transgenic plants. Directed evolution, an attempt to accelerate the evolutionary steps in the laboratory, is inherently simple when targeted for loss of function. A bigger challenge is to specify mutations that endow a new function, such as a lost functionality in a duplicated gene. Previously, we have proposed a method for enumerating candidates for mutations intended to transfer the functionality of one protein into another related protein based on the spatial and electrostatic properties of the active site residues (DECAAF. In the current work, we present in vivo validation of DECAAF by inducing tributyrin hydrolysis in LesB based on the active site similarity to LesA. The structures of these proteins have been modeled using RaptorX based on the closely related LipA protein from Xanthomonas oryzae. These mutations replicate the spatial and electrostatic conformation of LesA in the modeled structure of the mutant LesB as well, providing in silico validation before proceeding to the laborious in vivo work. Such focused mutations allows one to dissect the relevance of the duplicated genes in finer detail as compared to gene knockouts, since they do not interfere with other moonlighting functions, protein expression levels or protein-protein interaction.

Isolation and characterization of the human CDX1 gene: A candidate gene for diastrophic dysplasia

Energy Technology Data Exchange (ETDEWEB)

Bonner, C.; Loftus, S.; Wasmuth, J.J. [Univ. of California, Irvine, CA (United States)

1994-09-01

Diastrophic dysplasia is an autosomal recessive disorder characterized by short stature, dislocation of the joints, spinal deformities and malformation of the hands and feet. Multipoint linkage analysis places the diastrophic dysplasia (DTD) locus in 5q31-5q34. Linkage disequilibrium mapping places the DTD locus near CSFIR in the direction of PDGFRB (which is tandem to CSFIR). This same study tentatively placed PDGFRB and DTD proximal to CSFIR. Our results, as well as recently reported work from other laboratories, suggest that PDGFRB (and possibly DTD) is distal rather than proximal to CSFIR. We have constructed a cosmid contig covering approximately 200 kb of the region containing CSFIR. Several exons have been {open_quotes}trapped{close_quotes} from these cosmids using exon amplification. One of these exons was trapped from a cosmid isolated from a walk from PDGFRB, approximately 80 kb from CSFIR. This exon was sequenced and was determined to be 89% identical to the nucleotide sequence of exon two of the murine CDX1 gene (100% amino acid identity). The exon was used to isolate the human CDX gene. Sequence analysis of the human CDX1 gene indicates a very high degree of homology to the murine gene. CDX1 is a caudal type homeobox gene expressed during gastrulation. In the mouse, expression during gastrulation begins in the primitive streak and subsequently localizes to the ectodermal and mesodermal cells of the primitive streak, neural tube, somites, and limb buds. Later in gastrulation, CDX1 expression becomes most prominent in the mesoderm of the forelimbs, and, to a lesser extent, the hindlimbs. CDX1 is an intriguing candidate gene for diastrophic dysplasia. We are currently screening DNA from affected individuals and hope to shortly determine whether CDX1 is involved in this disorder.

Muscle segment homeobox genes direct embryonic diapause by limiting inflammation in the uterus

Energy Technology Data Exchange (ETDEWEB)

Cha, Jeeyeon; Burnum-Johnson, Kristin E.; Bartos, Amanda; Li, Yingju; Baker, Erin Shammel; Tilton, Susan C.; Webb-Robertson, Bobbie-Jo M.; Piehowski, Paul D.; Monroe, Matthew E.; Jegga, Anil; Murata, Shigeo; Hirota, Yasushi; Dey, Sudhansu K.

2015-06-11

Embryonic diapause (delayed implantation) is a reproductive strategy widespread in the animal kingdom. Under this condition, embryos at the blastocyst stage become dormant simultaneously with uterine quiescence until environmental or physiological conditions are favorable for the survival of the mother and newborn. Under favorable conditions, activation of the blastocyst and uterus ensues with implantation and progression of pregnancy. Although endocrine factors are known to participate in this process, the underlying molecular mechanism coordinating this phenomenon is not clearly understood. We recently found that uterine muscle segment homeobox (Msx) transcription factors are critical for the initiation and maintenance of delayed implantation in mice. To better understand why Msx genes are critical for delayed implantation, we compared uterine proteomics profiles between littermate floxed (Msx1/Msx2f/f) mice and mice with uterine deletion of Msx genes (Msx1/Msx2d/d) under delayed conditions. In Msx1/Msx2d/d uteri, pathways including protein translation, ubiquitin-proteasome system, inflammation, chaperone-mediated protein folding, and endoplasmic reticulum (ER) stress were enriched, and computational modeling showed intersection of these pathways on inflammatory responses. Indeed, increases in the ubiquitin-proteasome system and inflammation conformed to proteotoxic and ER stress in Msx1/Msx2d/d uteri under delayed conditions. Interestingly, treatment with a proteasome inhibitor bortezomib further exacerbated ER stress in Msx1/Msx2d/d uteri with aggravated inflammatory response, deteriorating rate of blastocyst recovery and failure to sustain delayed implantation. This study highlights a previously unrecognized role for Msx in preventing proteotoxic stress and inflammatory responses to coordinate embryo dormancy and uterine quiescence during embryonic diapause.

Transcriptional profiling identifies differentially expressed genes in developing turkey skeletal muscle

Directory of Open Access Journals (Sweden)

Velleman Sandra G

2011-03-01

Full Text Available Abstract Background Skeletal muscle growth and development from embryo to adult consists of a series of carefully regulated changes in gene expression. Understanding these developmental changes in agriculturally important species is essential to the production of high quality meat products. For example, consumer demand for lean, inexpensive meat products has driven the turkey industry to unprecedented production through intensive genetic selection. However, achievements of increased body weight and muscle mass have been countered by an increased incidence of myopathies and meat quality defects. In a previous study, we developed and validated a turkey skeletal muscle-specific microarray as a tool for functional genomics studies. The goals of the current study were to utilize this microarray to elucidate functional pathways of genes responsible for key events in turkey skeletal muscle development and to compare differences in gene expression between two genetic lines of turkeys. To achieve these goals, skeletal muscle samples were collected at three critical stages in muscle development: 18d embryo (hyperplasia, 1d post-hatch (shift from myoblast-mediated growth to satellite cell-modulated growth by hypertrophy, and 16wk (market age from two genetic lines: a randombred control line (RBC2 maintained without selection pressure, and a line (F selected from the RBC2 line for increased 16wk body weight. Array hybridizations were performed in two experiments: Experiment 1 directly compared the developmental stages within genetic line, while Experiment 2 directly compared the two lines within each developmental stage. Results A total of 3474 genes were differentially expressed (false discovery rate; FDR Conclusions The current study identified gene pathways and uncovered novel genes important in turkey muscle growth and development. Future experiments will focus further on several of these candidate genes and the expression and mechanism of action of

miR-122 promotes hepatic antioxidant defense of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) exposed to cadmium by directly targeting a metallothionein gene

International Nuclear Information System (INIS)

Qiang, Jun; Tao, Yi-Fan; He, Jie; Xu, Pao; Bao, Jin-Wen; Sun, Yi-Lan

2017-01-01

Highlights: • MiR-122 regulated tilapia MT by directly targeting MT 3′UTR. • MiR-122 level was negatively related to MT level under Cd stress. • MiR-122 silencing caused up-regulation of MT expression. • MiR-122 loss relieved liver stress and stimulated antioxidant enzymes. - Abastract: MicroRNAs (miRNAs) are small, non-coding RNAs that regulate target gene expression by binding to the 3′untranslated region (3′UTR) of the target mRNA. MiRNAs regulate a large variety of genes, including those involved in liver homeostasis and energy metabolism. Down-regulated levels of hepatic miR-122 were found in genetically improved farmed tilapia (GIFT, Oreochromis niloticus) exposed to cadmium (Cd) stress. Here, we report for the first time that reduction of miR-122 post-transcriptionally increased metallothionein (MT) mRNA levels by binding to its 3′UTR, as shown by a 3′ UTR luciferase reporter assay. The expression levels of miR-122 were negatively related to MT levels in GIFT under Cd stress. We performed in vivo functional analysis of miR-122 by injecting the fish with a miR-122 antagomir. Inhibition of miR-122 levels in GIFT liver caused a significant increase in MT expression, affected white blood cell and red blood cell counts, and serum alanine and aspartate aminotransferase activities, and glucose levels, all of which may help to relieve Cd stress-related liver stress. miR-122 silencing modulated oxidative stress and stimulated the activity of antioxidant enzymes. Our findings indicate that miR-122 regulated MT levels by binding to the 3′UTR of MT mRNA, and this interaction affected Cd stress induction and the resistance response in GIFT. We concluded that miR-122 plays an important role in regulating the stress response in GIFT liver. Our findings may contribute to understanding the mechanisms of miRNA-mediated gene regulation in tilapia in response to environmental stresses.

miR-122 promotes hepatic antioxidant defense of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) exposed to cadmium by directly targeting a metallothionein gene

Energy Technology Data Exchange (ETDEWEB)

Qiang, Jun, E-mail: Qiangj@ffrc.cn [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu (China); Tao, Yi-Fan [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); He, Jie [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu (China); Xu, Pao, E-mail: Xup@ffrc.cn [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu (China); Bao, Jin-Wen [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Sun, Yi-Lan [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, Jiangsu (China)

2017-01-15

Highlights: • MiR-122 regulated tilapia MT by directly targeting MT 3′UTR. • MiR-122 level was negatively related to MT level under Cd stress. • MiR-122 silencing caused up-regulation of MT expression. • MiR-122 loss relieved liver stress and stimulated antioxidant enzymes. - Abastract: MicroRNAs (miRNAs) are small, non-coding RNAs that regulate target gene expression by binding to the 3′untranslated region (3′UTR) of the target mRNA. MiRNAs regulate a large variety of genes, including those involved in liver homeostasis and energy metabolism. Down-regulated levels of hepatic miR-122 were found in genetically improved farmed tilapia (GIFT, Oreochromis niloticus) exposed to cadmium (Cd) stress. Here, we report for the first time that reduction of miR-122 post-transcriptionally increased metallothionein (MT) mRNA levels by binding to its 3′UTR, as shown by a 3′ UTR luciferase reporter assay. The expression levels of miR-122 were negatively related to MT levels in GIFT under Cd stress. We performed in vivo functional analysis of miR-122 by injecting the fish with a miR-122 antagomir. Inhibition of miR-122 levels in GIFT liver caused a significant increase in MT expression, affected white blood cell and red blood cell counts, and serum alanine and aspartate aminotransferase activities, and glucose levels, all of which may help to relieve Cd stress-related liver stress. miR-122 silencing modulated oxidative stress and stimulated the activity of antioxidant enzymes. Our findings indicate that miR-122 regulated MT levels by binding to the 3′UTR of MT mRNA, and this interaction affected Cd stress induction and the resistance response in GIFT. We concluded that miR-122 plays an important role in regulating the stress response in GIFT liver. Our findings may contribute to understanding the mechanisms of miRNA-mediated gene regulation in tilapia in response to environmental stresses.

Molecular characterization of rpoB gene encoding the RNA ...

African Journals Online (AJOL)

Polymerase chain reaction (PCR) mediated direct DNA sequencing was evaluated for rapid detection of Rifampicin resistance (RMPr) of Mycobacterium tuberculosis. After amplification of the rpoB gene, the product was sequenced using ABI 310 Genetic Analyzer and the rifampicin resistance in M. tuberculosis were ...

Toolboxes for cyanobacteria: Recent advances and future direction.

Science.gov (United States)

Sun, Tao; Li, Shubin; Song, Xinyu; Diao, Jinjin; Chen, Lei; Zhang, Weiwen

2018-05-03

Photosynthetic cyanobacteria are important primary producers and model organisms for studying photosynthesis and elements cycling on earth. Due to the ability to absorb sunlight and utilize carbon dioxide, cyanobacteria have also been proposed as renewable chassis for carbon-neutral "microbial cell factories". Recent progresses on cyanobacterial synthetic biology have led to the successful production of more than two dozen of fuels and fine chemicals directly from CO 2 , demonstrating their potential for scale-up application in the future. However, compared with popular heterotrophic chassis like Escherichia coli and Saccharomyces cerevisiae, where abundant genetic tools are available for manipulations at levels from single gene, pathway to whole genome, limited genetic tools are accessible to cyanobacteria. Consequently, this significant technical hurdle restricts both the basic biological researches and further development and application of these renewable systems. Though still lagging the heterotrophic chassis, the vital roles of genetic tools in tuning of gene expression, carbon flux re-direction as well as genome-wide manipulations have been increasingly recognized in cyanobacteria. In recent years, significant progresses on developing and introducing new and efficient genetic tools have been made for cyanobacteria, including promoters, riboswitches, ribosome binding site engineering, clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease (CRISPR/Cas) systems, small RNA regulatory tools and genome-scale modeling strategies. In this review, we critically summarize recent advances on development and applications as well as technical limitations and future directions of the genetic tools in cyanobacteria. In addition, toolboxes feasible for using in large-scale cultivation are also briefly discussed. Copyright © 2018 Elsevier Inc. All rights reserved.

GoGene: gene annotation in the fast lane.

Science.gov (United States)

Plake, Conrad; Royer, Loic; Winnenburg, Rainer; Hakenberg, Jörg; Schroeder, Michael

2009-07-01

High-throughput screens such as microarrays and RNAi screens produce huge amounts of data. They typically result in hundreds of genes, which are often further explored and clustered via enriched GeneOntology terms. The strength of such analyses is that they build on high-quality manual annotations provided with the GeneOntology. However, the weakness is that annotations are restricted to process, function and location and that they do not cover all known genes in model organisms. GoGene addresses this weakness by complementing high-quality manual annotation with high-throughput text mining extracting co-occurrences of genes and ontology terms from literature. GoGene contains over 4,000,000 associations between genes and gene-related terms for 10 model organisms extracted from more than 18,000,000 PubMed entries. It does not cover only process, function and location of genes, but also biomedical categories such as diseases, compounds, techniques and mutations. By bringing it all together, GoGene provides the most recent and most complete facts about genes and can rank them according to novelty and importance. GoGene accepts keywords, gene lists, gene sequences and protein sequences as input and supports search for genes in PubMed, EntrezGene and via BLAST. Since all associations of genes to terms are supported by evidence in the literature, the results are transparent and can be verified by the user. GoGene is available at http://gopubmed.org/gogene.

Identification of miR-2400 gene as a novel regulator in skeletal muscle satellite cells proliferation by targeting MYOG gene

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei Wei [The Laboratory of Cell and Development, Northeast Agricultural University, Harbin, Heilongjiang 150030 (China); College of Life Sciences and Agriculture & Forestry, Qiqihar University, Qiqihar, Heilongjiang 161006 (China); Tong, Hui Li; Sun, Xiao Feng; Hu, Qian; Yang, Yu; Li, Shu Feng [The Laboratory of Cell and Development, Northeast Agricultural University, Harbin, Heilongjiang 150030 (China); Yan, Yun Qin, E-mail: yanyunqin@sohu.com [The Laboratory of Cell and Development, Northeast Agricultural University, Harbin, Heilongjiang 150030 (China); Li, Guang Peng [The Key Laboratory of Mammal Reproductive Biology and Biotechnology Ministry of Education, Inner Mongolia University, Hohhot 010021 (China)

2015-08-07

MicroRNAs play critical roles in skeletal muscle development as well as in regulation of muscle cell proliferation and differentiation. Previous study in our laboratory showed that the expression level of miR-2400, a novel and unique miRNA from bovine, had significantly changed in skeletal muscle-derived satellite cells (MDSCs) during differentiation, however, the function and expression pattern for miR-2400 in MDSCs has not been fully understood. In this report, we firstly identified that the expression levels of miR-2400 were down-regulated during MDSCs differentiation by stem-loop RT-PCR. Over-expression and inhibition studies demonstrated that miR-2400 promoted MDSCs proliferation by EdU (5-ethynyl-2′ deoxyuridine) incorporation assay and immunofluorescence staining of Proliferating cell nuclear antigen (PCNA). Luciferase reporter assays showed that miR-2400 directly targeted the 3′ untranslated regions (UTRs) of myogenin (MYOG) mRNA. These data suggested that miR-2400 could promote MDSCs proliferation through targeting MYOG. Furthermore, we found that miR-2400, which was located within the eighth intron of the Wolf-Hirschhorn syndrome candidate 1-like 1 (WHSC1L1) gene, was down-regulated in MDSCs in a direct correlation with the WHSC1L1 transcript by Clustered regularly interspaced palindromic repeats interference (CRISPRi). In addition, these observations not only provided supporting evidence for the codependent expression of intronic miRNAs and their host genes in vitro, but also gave insight into the role of miR-2400 in MDSCs proliferation. - Highlights: • miR-2400 is a novel and unique miRNA from bovine. • miR-2400 could promote skeletal muscle satellite cells proliferation. • miR-2400 directly targeted the 3′ untranslated regions of MYOG mRNA. • miR-2400 could be coexpressed together with its host gene WHSC1L1.

Sperm competition, immunity, selfish genes and cancer.

Science.gov (United States)

Lewis, Z; Price, T A R; Wedell, N

2008-10-01

Sperm competition is widespread and has played an important role in shaping male reproductive characters such as testis size and numbers of sperm produced, and this is reflected in the rapid evolution of many reproductive genes. Additionally, sperm competition has been implicated in the rapid evolution of seminal fluids. However, our understanding of the molecular basis of many traits thought to be important in sperm competition is rudimentary. Furthermore, links between sperm competition and a range of issues not directly related to reproduction are only just beginning to be explored. These include associations between sperm competition and selfish genes, immunity and diseases such as cancer.We briefly review these topics and suggest areas we consider worthy of additional research.

Biosensor-controlled gene therapy/drug delivery with nanoparticles for nanomedicine

Science.gov (United States)

Prow, Tarl W.; Rose, William A.; Wang, Nan; Reece, Lisa M.; Lvov, Yuri; Leary, James F.

2005-04-01

Nanomedicine involves cell-by-cell regenerative medicine, either repairing cells one at a time or triggering apoptotic pathways in cells that are not repairable. Multilayered nanoparticle systems are being constructed for the targeted delivery of gene therapy to single cells. Cleavable shells containing targeting, biosensing, and gene therapeutic molecules are being constructed to direct nanoparticles to desired intracellular targets. Therapeutic gene sequences are controlled by biosensor-activated control switches to provide the proper amount of gene therapy on a single cell basis. The central idea is to set up gene therapy "nanofactories" inside single living cells. Molecular biosensors linked to these genes control their expression. Gene delivery is started in response to a biosensor detected problem; gene delivery is halted when the cell response indicates that more gene therapy is not needed. Cell targeting of nanoparticles, both nanocrystals and nanocapsules, has been tested by a combination of fluorescent tracking dyes, fluorescence microscopy and flow cytometry. Intracellular targeting has been tested by confocal microscopy. Successful gene delivery has been visualized by use of GFP reporter sequences. DNA tethering techniques were used to increase the level of expression of these genes. Integrated nanomedical systems are being designed, constructed, and tested in-vitro, ex-vivo, and in small animals. While still in its infancy, nanomedicine represents a paradigm shift in thinking-from destruction of injured cells by surgery, radiation, chemotherapy to cell-by-cell repair within an organ and destruction of non-repairable cells by natural apoptosis.