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Sample records for hcb-23 recombinant mouse

  1. The recombinational anatomy of a mouse chromosome.

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    Kenneth Paigen

    2008-07-01

    Full Text Available Among mammals, genetic recombination occurs at highly delimited sites known as recombination hotspots. They are typically 1-2 kb long and vary as much as a 1,000-fold or more in recombination activity. Although much is known about the molecular details of the recombination process itself, the factors determining the location and relative activity of hotspots are poorly understood. To further our understanding, we have collected and mapped the locations of 5,472 crossover events along mouse Chromosome 1 arising in 6,028 meioses of male and female reciprocal F1 hybrids of C57BL/6J and CAST/EiJ mice. Crossovers were mapped to a minimum resolution of 225 kb, and those in the telomere-proximal 24.7 Mb were further mapped to resolve individual hotspots. Recombination rates were evolutionarily conserved on a regional scale, but not at the local level. There was a clear negative-exponential relationship between the relative activity and abundance of hotspot activity classes, such that a small number of the most active hotspots account for the majority of recombination. Females had 1.2x higher overall recombination than males did, although the sex ratio showed considerable regional variation. Locally, entirely sex-specific hotspots were rare. The initiation of recombination at the most active hotspot was regulated independently on the two parental chromatids, and analysis of reciprocal crosses indicated that parental imprinting has subtle effects on recombination rates. It appears that the regulation of mammalian recombination is a complex, dynamic process involving multiple factors reflecting species, sex, individual variation within species, and the properties of individual hotspots.

  2. Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

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    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2017-02-01

    Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

  3. Cis- and trans-acting elements regulate the mouse Psmb9 meiotic recombination hotspot.

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    Frédéric Baudat

    2007-06-01

    Full Text Available In most eukaryotes, the prophase of the first meiotic division is characterized by a high level of homologous recombination between homologous chromosomes. Recombination events are not distributed evenly within the genome, but vary both locally and at large scale. Locally, most recombination events are clustered in short intervals (a few kilobases called hotspots, separated by large intervening regions with no or very little recombination. Despite the importance of regulating both the frequency and the distribution of recombination events, the genetic factors controlling the activity of the recombination hotspots in mammals are still poorly understood. We previously characterized a recombination hotspot located close to the Psmb9 gene in the mouse major histocompatibility complex by sperm typing, demonstrating that it is a site of recombination initiation. With the goal of uncovering some of the genetic factors controlling the activity of this initiation site, we analyzed this hotspot in both male and female germ lines and compared the level of recombination in different hybrid mice. We show that a haplotype-specific element acts at distance and in trans to activate about 2,000-fold the recombination activity at Psmb9. Another haplotype-specific element acts in cis to repress initiation of recombination, and we propose this control to be due to polymorphisms located within the initiation zone. In addition, we describe subtle variations in the frequency and distribution of recombination events related to strain and sex differences. These findings show that most regulations observed act at the level of initiation and provide the first analysis of the control of the activity of a meiotic recombination hotspot in the mouse genome that reveals the interactions of elements located both in and outside the hotspot.

  4. Extensive recombination rate variation in the house mouse species complex inferred from genetic linkage maps.

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    Dumont, Beth L; White, Michael A; Steffy, Brian; Wiltshire, Tim; Payseur, Bret A

    2011-01-01

    The rate of recombination is a key genomic parameter that displays considerable variation among taxa. Species comparisons have demonstrated that the rate of evolution in recombination rate is strongly dependent on the physical scale of measurement. Individual recombination hotspots are poorly conserved among closely related taxa, whereas genomic-scale recombination rate variation bears a strong signature of phylogenetic history. In contrast, the mode and tempo of evolution in recombination rates measured on intermediate physical scales is poorly understood. Here, we conduct a detailed statistical comparison between two whole-genome F₂ genetic linkage maps constructed from experimental intercrosses between closely related house mouse subspecies (Mus musculus). Our two maps profile a common wild-derived inbred strain of M. m. domesticus crossed to distinct wild-derived inbred strains representative of two other house mouse subspecies, M. m. castaneus and M. m. musculus. We identify numerous orthologous genomic regions with significant map length differences between these two crosses. Because the genomes of these recently diverged house mice are highly collinear, observed differences in map length (centimorgans) are suggestive of variation in broadscale recombination rate (centimorgans per megabase) within M. musculus. Collectively, these divergent intervals span 19% of the house mouse genome, disproportionately aggregating on the X chromosome. In addition, we uncover strong statistical evidence for a large effect, sex-linked, site-specific modifier of recombination rate segregating within M. musculus. Our findings reveal considerable variation in the megabase-scale recombination landscape among recently diverged taxa and underscore the continued importance of genetic linkage maps in the post-genome era.

  5. A pink mouse reports the switch from red to green fluorescence upon Cre-mediated recombination

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    Hartwich Heiner

    2012-06-01

    Full Text Available Abstract Background Targeted genetic modification in the mouse becomes increasingly important in biomedical and basic science. This goal is most often achieved by use of the Cre/loxP system and numerous Cre-driver mouse lines are currently generated. Their initial characterization requires reporter mouse lines to study the in vivo spatiotemporal activity of Cre. Findings Here, we report a dual fluorescence reporter mouse line, which switches expression from the red fluorescent protein mCherry to eGFP after Cre-mediated recombination. Both fluorescent proteins are expressed from the ubiquitously active and strong CAGGS promoter. Among the founders, we noticed a pink mouse line, expressing high levels of the red fluorescent protein mCherry throughout the entire body. Presence of mCherry in the living animal as well as in almost all organs was clearly visible without optical equipment. Upon Cre-activity, mCherry expression was switched to eGFP, demonstrating functionality of this reporter mouse line. Conclusions The pink mouse presented here is an attractive novel reporter line for fluorescence-based monitoring of Cre-activity. The high expression of mCherry, which is visible to the naked eye, facilitates breeding and crossing, as no genotyping is required to identify mice carrying the reporter allele. The presence of two fluorescent proteins allows in vivo monitoring of recombined and non-recombined cells. Finally, the pink mouse is an eye-catching animal model to demonstrate the power of transgenic techniques in teaching courses.

  6. Hybrid Sterility Locus on Chromosome X Controls Meiotic Recombination Rate in Mouse.

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    Maria Balcova

    2016-04-01

    Full Text Available Meiotic recombination safeguards proper segregation of homologous chromosomes into gametes, affects genetic variation within species, and contributes to meiotic chromosome recognition, pairing and synapsis. The Prdm9 gene has a dual role, it controls meiotic recombination by determining the genomic position of crossover hotspots and, in infertile hybrids of house mouse subspecies Mus m. musculus (Mmm and Mus m. domesticus (Mmd, it further functions as the major hybrid sterility gene. In the latter role Prdm9 interacts with the hybrid sterility X 2 (Hstx2 genomic locus on Chromosome X (Chr X by a still unknown mechanism. Here we investigated the meiotic recombination rate at the genome-wide level and its possible relation to hybrid sterility. Using immunofluorescence microscopy we quantified the foci of MLH1 DNA mismatch repair protein, the cytological counterparts of reciprocal crossovers, in a panel of inter-subspecific chromosome substitution strains. Two autosomes, Chr 7 and Chr 11, significantly modified the meiotic recombination rate, yet the strongest modifier, designated meiotic recombination 1, Meir1, emerged in the 4.7 Mb Hstx2 genomic locus on Chr X. The male-limited transgressive effect of Meir1 on recombination rate parallels the male-limited transgressive role of Hstx2 in hybrid male sterility. Thus, both genetic factors, the Prdm9 gene and the Hstx2/Meir1 genomic locus, indicate a link between meiotic recombination and hybrid sterility. A strong female-specific modifier of meiotic recombination rate with the effect opposite to Meir1 was localized on Chr X, distally to Meir1. Mapping Meir1 to a narrow candidate interval on Chr X is an important first step towards positional cloning of the respective gene(s responsible for variation in the global recombination rate between closely related mouse subspecies.

  7. Hybrid Sterility Locus on Chromosome X Controls Meiotic Recombination Rate in Mouse.

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    Balcova, Maria; Faltusova, Barbora; Gergelits, Vaclav; Bhattacharyya, Tanmoy; Mihola, Ondrej; Trachtulec, Zdenek; Knopf, Corinna; Fotopulosova, Vladana; Chvatalova, Irena; Gregorova, Sona; Forejt, Jiri

    2016-04-01

    Meiotic recombination safeguards proper segregation of homologous chromosomes into gametes, affects genetic variation within species, and contributes to meiotic chromosome recognition, pairing and synapsis. The Prdm9 gene has a dual role, it controls meiotic recombination by determining the genomic position of crossover hotspots and, in infertile hybrids of house mouse subspecies Mus m. musculus (Mmm) and Mus m. domesticus (Mmd), it further functions as the major hybrid sterility gene. In the latter role Prdm9 interacts with the hybrid sterility X 2 (Hstx2) genomic locus on Chromosome X (Chr X) by a still unknown mechanism. Here we investigated the meiotic recombination rate at the genome-wide level and its possible relation to hybrid sterility. Using immunofluorescence microscopy we quantified the foci of MLH1 DNA mismatch repair protein, the cytological counterparts of reciprocal crossovers, in a panel of inter-subspecific chromosome substitution strains. Two autosomes, Chr 7 and Chr 11, significantly modified the meiotic recombination rate, yet the strongest modifier, designated meiotic recombination 1, Meir1, emerged in the 4.7 Mb Hstx2 genomic locus on Chr X. The male-limited transgressive effect of Meir1 on recombination rate parallels the male-limited transgressive role of Hstx2 in hybrid male sterility. Thus, both genetic factors, the Prdm9 gene and the Hstx2/Meir1 genomic locus, indicate a link between meiotic recombination and hybrid sterility. A strong female-specific modifier of meiotic recombination rate with the effect opposite to Meir1 was localized on Chr X, distally to Meir1. Mapping Meir1 to a narrow candidate interval on Chr X is an important first step towards positional cloning of the respective gene(s) responsible for variation in the global recombination rate between closely related mouse subspecies.

  8. Purification and characterization of recombinant baculovirus-expressed mouse DNA methyltransferase.

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    Glickman, J F; Flynn, J; Reich, N O

    1997-01-13

    DNA methylation is essential for normal embryonic development in mice. An understanding of how DNA methylation is controlled is largely dependent upon the isolation and characterization of the cellular components of the DNA methylation system. The enzyme which methylates DNA in eukaryotic cells is a C-5 cytosine DNA methyltransferase. Historically, the characterization of this enzyme has been limited by its availability and purity. Here, we present a single-step purification of 4 mg of baculovirus-expressed mouse DNA methyltransferase containing a nickel-affinity leader peptide. The recombinant DNA methyltransferase copurified with inhibitory RNA which was removed by treatment with ribonuclease A. Like its non-recombinant counterpart, the recombinant enzyme is activated by hemi-methylation. A direct steady-state kinetic comparison between the recombinant baculovirus-expressed enzyme with its MEL cell-derived counterpart is presented.

  9. Recombinant Goat VEGF164 Increases Hair Growth by Painting Process on the Skin of Shaved Mouse

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    Wenlei Bao

    2014-09-01

    Full Text Available To detect goat vascular endothelial growth factor (VEGF-mediated regrowth of hair, full-length VEGF164 cDNA was cloned from Inner Mongolia cashmere goat (Capra hircus into the pET-his prokaryotic expression vector, and the recombinant plasmid was transferred into E. coli BL21 cells. The expression of recombinant 6×his-gVEGF164 protein was induced by 0.5 mM isopropyl thio-β-D-galactoside at 32°C. Recombinant goat VEGF164 (rgVEGF164 was purified and identi ed by western blot using monoclonal anti-his and anti-VEGF antibodies. The rgVEGF164 was smeared onto the dorsal area of a shaved mouse, and we noted that hair regrowth in this area was faster than in the control group. Thus, rgVEGF164 increases hair growth in mice.

  10. Patterns of recombination activity on mouse chromosome 11 revealed by high resolution mapping.

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    Timothy Billings

    Full Text Available The success of high resolution genetic mapping of disease predisposition and quantitative trait loci in humans and experimental animals depends on the positions of key crossover events around the gene of interest. In mammals, the majority of recombination occurs at highly delimited 1-2 kb long sites known as recombination hotspots, whose locations and activities are distributed unevenly along the chromosomes and are tightly regulated in a sex specific manner. The factors determining the location of hotspots started to emerge with the finding of PRDM9 as a major hotspot regulator in mammals, however, additional factors modulating hotspot activity and sex specificity are yet to be defined. To address this limitation, we have collected and mapped the locations of 4829 crossover events occurring on mouse chromosome 11 in 5858 meioses of male and female reciprocal F1 hybrids of C57BL/6J and CAST/EiJ mice. This chromosome was chosen for its medium size and high gene density and provided a comparison with our previous analysis of recombination on the longest mouse chromosome 1. Crossovers were mapped to an average resolution of 127 kb, and thirteen hotspots were mapped to <8 kb. Most crossovers occurred in a small number of the most active hotspots. Females had higher recombination rate than males as a consequence of differences in crossover interference and regional variation of sex specific rates along the chromosome. Comparison with chromosome 1 showed that recombination events tend to be positioned in similar fashion along the centromere-telomere axis but independently of the local gene density. It appears that mammalian recombination is regulated on at least three levels, chromosome-wide, regional, and at individual hotspots, and these regulation levels are influenced by sex and genetic background but not by gene content.

  11. Use of Thymidine Kinase Recombinant Adenovirus and Ganciclovir Mediated Mouse Liver Preconditioning for Hepatocyte Xenotransplantation.

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    Moreno, Daniel; Neri, Leire; Vicente, Eva; Vales, Africa; Aldabe, Rafael

    2017-01-01

    Hepatocyte transplantation is the best approach to maintain and propagate differentiated hepatocytes from different species. Host liver has to be adapted for transplanted hepatocytes productive engraftment and proliferation being required a chronic liver injury to eliminate host hepatocytes and provide a proliferative advantage to the transplanted hepatocytes. Most valuable mouse models for xenograft hepatocyte transplantation are based on genetically modified animals to cause a chronic liver damage and to limit host hepatocyte regeneration potential. We present a methodology that generates a chronic liver damage and can be applied to any host mouse strain and animal species based on the inoculation of a recombinant adenovirus to express herpes simplex thymidine kinase in host hepatocytes sensitizing them to ganciclovir treatment. This causes a prolonged liver damage that allows hepatocyte transplantation and generation of regenerative nodules in recipient mouse liver integrated by transplanted cells and host sinusoidal. Obtained chimeric animals maintain functional chimeric nodules for several weeks, ready to be used in any study.

  12. In vivo Importance of Homologous Recombination DNA Repair for Mouse Neural Stem and Progenitor Cells

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    Rousseau, Laure; Etienne, Olivier; Roque, Telma; Desmaze, Chantal; Haton, Céline; Mouthon, Marc-André; Bernardino-Sgherri, Jacqueline; Essers, Jeroen; Kanaar, Roland; Boussin, François D.

    2012-01-01

    We characterized the in vivo importance of the homologous recombination factor RAD54 for the developing mouse brain cortex in normal conditions or after ionizing radiation exposure. Contrary to numerous homologous recombination genes, Rad54 disruption did not impact the cortical development without exogenous stress, but it dramatically enhanced the radiation sensitivity of neural stem and progenitor cells. This resulted in the death of all cells irradiated during S or G2, whereas the viability of cells irradiated in G1 or G0 was not affected by Rad54 disruption. Apoptosis occurred after long arrests at intra-S and G2/M checkpoints. This concerned every type of neural stem and progenitor cells, showing that the importance of Rad54 for radiation response was linked to the cell cycle phase at the time of irradiation and not to the differentiation state. In the developing brain, RAD54-dependent homologous recombination appeared absolutely required for the repair of damages induced by ionizing radiation during S and G2 phases, but not for the repair of endogenous damages in normal conditions. Altogether our data support the existence of RAD54-dependent and -independent homologous recombination pathways. PMID:22666344

  13. Specific transduction and labeling of pancreatic ducts by targeted recombinant viral infusion into mouse pancreatic ducts.

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    Guo, Ping; Xiao, Xiangwei; El-Gohary, Yousef; Criscimanna, Angela; Prasadan, Krishna; Rymer, Christopher; Shiota, Chiyo; Wiersch, John; Gaffar, Iliana; Esni, Farzad; Gittes, George K

    2013-11-01

    Specific labeling of pancreatic ducts has proven to be quite difficult. Such labeling has been highly sought after because of the power it would confer to studies of pancreatic ductal carcinogenesis, as well as studies of the source of new insulin-producing β-cells. Cre-loxp recombination could, in theory, lineage-tag pancreatic ducts, but results have been conflicting, mainly due to low labeling efficiencies. Here, we achieved a high pancreatic duct labeling efficiency using a recombinant adeno-associated virus (rAAV) with a duct-specific sox9 promoter infused into the mouse common biliary/pancreatic duct. We saw rapid, diffuse duct-specific labeling, with 50 and 89% labeling in the pancreatic tail and head region, respectively. This highly specific labeling of ducts should greatly enhance our ability to study the role of pancreatic ducts in numerous aspects of pancreatic growth, development and function.

  14. A rapid and scalable method for selecting recombinant mouse monoclonal antibodies

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    Wright Gavin J

    2010-06-01

    Full Text Available Abstract Background Monoclonal antibodies with high affinity and selectivity that work on wholemount fixed tissues are valuable reagents to the cell and developmental biologist, and yet isolating them remains a long and unpredictable process. Here we report a rapid and scalable method to select and express recombinant mouse monoclonal antibodies that are essentially equivalent to those secreted by parental IgG-isotype hybridomas. Results Increased throughput was achieved by immunizing mice with pools of antigens and cloning - from small numbers of hybridoma cells - the functionally rearranged light and heavy chains into a single expression plasmid. By immunizing with the ectodomains of zebrafish cell surface receptor proteins expressed in mammalian cells and screening for formalin-resistant epitopes, we selected antibodies that gave expected staining patterns on wholemount fixed zebrafish embryos. Conclusions This method can be used to quickly select several high quality monoclonal antibodies from a single immunized mouse and facilitates their distribution using plasmids.

  15. Interallelic class switch recombination contributes significantly to class switching in mouse B cells.

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    Reynaud, Stéphane; Delpy, Laurent; Fleury, Laurence; Dougier, Hei-Lanne; Sirac, Christophe; Cogné, Michel

    2005-05-15

    Except for the expression of IgM and IgD, DNA recombination is constantly needed for the expression of other Ig classes and subclasses. The predominant path of class switch recombination (CSR) is intrachromosomal, and the looping-out and deletion model has been abundantly documented. However, switch regions also occasionally constitute convenient substrates for interchromosomal recombination, since it is noticeably the case in a number of chromosomal translocations causing oncogene deregulation in the course of lymphoma and myeloma. Although asymmetric accessibility of Ig alleles should theoretically limit its occurrence, interallelic CSR was shown to occur at low levels during IgA switching in rabbit, where the definition of allotypes within both V and C regions helped identify interchromosomally derived Ig. Thus, we wished to evaluate precisely interallelic CSR frequency in mouse B cells, by using a system in which only one allele (of b allotype) could express a functional VDJ region, whereas only interallelic CSR could restore expression of an excluded (a allotype) allele. In our study, we show that interchromosomal recombination of V(H) and Cgamma or Calpha occurs in vivo in B cells at a frequency that makes a significant contribution to physiological class switching: trans-association of V(H) and C(H) genes accounted for 7% of all alpha mRNA, and this frequency was about twice higher for the gamma3 transcripts, despite the much shorter distance between the J(H) region and the Cgamma3 gene, thus confirming that this phenomenon corresponded to site-specific switching and not to random recombination between long homologous loci.

  16. Construction of a recombinant bacterial plasmid containing DNA sequences for a mouse embryonic globin chain.

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    Fantoni, A; Bozzoni, I; Ullu, E; Farace, M G

    1979-08-10

    Messenger RNAs for mouse embryonic globins were purified from yolk sac derived eyrthroid cells in mouse fetuses. Double stranded DNAs complementary to these messengers were synthesized and blunt end ligated to a EcoRI digested and DNA polymerase I repaired pBR322 plasmid. Of the ampicillin resistant transformants, one contained a plasmid with globin-specific cDNA. The inserted sequence is about 350 base pairs long. It contains one restriction site for EcoRI and one restriction site for HinfI about 170 and 80 base pairs from one end. The insert is not cleaved by HindIII, HindII, BamHI, PstI, SalI, AvaI, TaqI, HpaII, BglI. A mixture of purified messengers coding for alpha chains and for x, y and z embryonic chains was incubated with the recombinant plasmid and the hybridized messenger was translated in a mRNA depleted reticulocyte lysate protein synthesizing system. The product of translation was identified as a z chain by carboxymethylcellulose cromatography. The recombinant plasmid is named "pBR322-egz" after embryonic globin z.

  17. The ATM signaling cascade promotes recombination-dependent pachytene arrest in mouse spermatocytes.

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    Sarai Pacheco

    2015-03-01

    Full Text Available Most mutations that compromise meiotic recombination or synapsis in mouse spermatocytes result in arrest and apoptosis at the pachytene stage of the first meiotic prophase. Two main mechanisms are thought to trigger arrest: one independent of the double-strand breaks (DSBs that initiate meiotic recombination, and another activated by persistent recombination intermediates. Mechanisms underlying the recombination-dependent arrest response are not well understood, so we sought to identify factors involved by examining mutants deficient for TRIP13, a conserved AAA+ ATPase required for the completion of meiotic DSB repair. We find that spermatocytes with a hypomorphic Trip13 mutation (Trip13mod/mod arrest with features characteristic of early pachynema in wild type, namely, fully synapsed chromosomes without incorporation of the histone variant H1t into chromatin. These cells then undergo apoptosis, possibly in response to the arrest or in response to a defect in sex body formation. However, TRIP13-deficient cells that additionally lack the DSB-responsive kinase ATM progress further, reaching an H1t-positive stage (i.e., similar to mid/late pachynema in wild type despite the presence of unrepaired DSBs. TRIP13-deficient spermatocytes also progress to an H1t-positive stage if ATM activity is attenuated by hypomorphic mutations in Mre11 or Nbs1 or by elimination of the ATM-effector kinase CHK2. These mutant backgrounds nonetheless experience an apoptotic block to further spermatogenic progression, most likely caused by failure to form a sex body. DSB numbers are elevated in Mre11 and Nbs1 hypomorphs but not Chk2 mutants, thus delineating genetic requirements for the ATM-dependent negative feedback loop that regulates DSB numbers. The findings demonstrate for the first time that ATM-dependent signaling enforces the normal pachytene response to persistent recombination intermediates. Our work supports the conclusion that recombination defects trigger

  18. NMDAR encephalitis: passive transfer from man to mouse by a recombinant antibody.

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    Malviya, Manish; Barman, Sumanta; Golombeck, Kristin S; Planagumà, Jesús; Mannara, Francesco; Strutz-Seebohm, Nathalie; Wrzos, Claudia; Demir, Fatih; Baksmeier, Christine; Steckel, Julia; Falk, Kim Kristin; Gross, Catharina C; Kovac, Stjepana; Bönte, Kathrin; Johnen, Andreas; Wandinger, Klaus-Peter; Martín-García, Elena; Becker, Albert J; Elger, Christian E; Klöcker, Nikolaj; Wiendl, Heinz; Meuth, Sven G; Hartung, Hans-Peter; Seebohm, Guiscard; Leypoldt, Frank; Maldonado, Rafael; Stadelmann, Christine; Dalmau, Josep; Melzer, Nico; Goebels, Norbert

    2017-11-01

    Autoimmune encephalitis is most frequently associated with anti-NMDAR autoantibodies. Their pathogenic relevance has been suggested by passive transfer of patients' cerebrospinal fluid (CSF) in mice in vivo. We aimed to analyze the intrathecal plasma cell repertoire, identify autoantibody-producing clones, and characterize their antibody signatures in recombinant form. Patients with recent onset typical anti-NMDAR encephalitis were subjected to flow cytometry analysis of the peripheral and intrathecal immune response before, during, and after immunotherapy. Recombinant human monoclonal antibodies (rhuMab) were cloned and expressed from matching immunoglobulin heavy- (IgH) and light-chain (IgL) amplicons of clonally expanded intrathecal plasma cells (cePc) and tested for their pathogenic relevance. Intrathecal accumulation of B and plasma cells corresponded to the clinical course. The presence of cePc with hypermutated antigen receptors indicated an antigen-driven intrathecal immune response. Consistently, a single recombinant human GluN1-specific monoclonal antibody, rebuilt from intrathecal cePc, was sufficient to reproduce NMDAR epitope specificity in vitro. After intraventricular infusion in mice, it accumulated in the hippocampus, decreased synaptic NMDAR density, and caused severe reversible memory impairment, a key pathogenic feature of the human disease, in vivo. A CNS-specific humoral immune response is present in anti-NMDAR encephalitis specifically targeting the GluN1 subunit of the NMDAR. Using reverse genetics, we recovered the typical intrathecal antibody signature in recombinant form, and proved its pathogenic relevance by passive transfer of disease symptoms from man to mouse, providing the critical link between intrathecal immune response and the pathogenesis of anti-NMDAR encephalitis as a humorally mediated autoimmune disease.

  19. Expression and Purification of Recombinant Mouse Interleukin-4 and -6 from Transgenic Rice Seeds.

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    Fujiwara, Yoshihiro; Yang, Lijun; Takaiwa, Fumio; Sekikawa, Kenji

    2016-04-01

    Transgenic rice seed can be utilized as a bioreactor to produce high-value recombinant proteins. Mouse interleukin 4 (mIL-4) and mIL-6 were specifically expressed as secretory proteins in rice endosperm by ligating the N-terminal glutelin B-1 (GluB-1) signal peptide and the C-terminal KDEL endoplasmic reticulum retention signal under control of the endosperm-specific GluB-1 promoter. In the transgenic rice seed, mIL-4 and mIL-6 accumulated in levels up to 0.43 mg/g grain and 0.16 mg/g grain, respectively. The reducing agents and detergents required for extraction from the transgenic rice seeds differed between the two proteins, indicating differences in their intracellular localization within the endosperm cell. Purified mIL-4 and mIL-6 exhibited high activity and very low endotoxin contamination.

  20. Cloning of human and mouse genes homologous to RAD52, a yeast gene involved in DNA repair and recombination.

    NARCIS (Netherlands)

    D.F.R. Muris; O.Y. Bezzubova (Olga); J-M. Buerstedde; K. Vreeken; A.S. Balajee; C.J. Osgood; C. Troelstra (Christine); J.H.J. Hoeijmakers (Jan); K. Ostermann; H. Schmidt (Henning); A.T. Natarajan; J.C.J. Eeken; P.H.M. Lohmann (Paul); A. Pastink (Albert)

    1994-01-01

    textabstractThe RAD52 gene of Saccharomyces cerevisiae is required for recombinational repair of double-strand breaks. Using degenerate oligonucleotides based on conserved amino acid sequences of RAD52 and rad22, its counterpart from Schizosaccharomyces pombe, RAD52 homologs from man and mouse were

  1. Construction and characterization of recombinant adenovirus carrying a mouse TIGIT-GFP gene.

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    Zheng, J M; Cui, J L; He, W T; Yu, D W; Gao, Y; Wang, L; Chen, Z K; Zhou, H M

    2015-12-29

    Recombinant adenovirus vector systems have been used extensively in protein research and gene therapy. However, the construction and characterization of recombinant adenovirus is a tedious and time-consuming process. TIGIT is a recently discovered immunosuppressive molecule that plays an important role in maintaining immunological balance. The construction of recombinant adenovirus mediating TIGIT expression must be simplified to facilitate its use in the study of TIGIT. In this study, the TIGIT gene was combined with green fluorescent protein (GFP); the TIGIT-GFP gene was inserted into a gateway plasmid to construct a TIGIT-GFP adenovirus. HEK 293A cells were infected with the adenovirus, which was then purified and subjected to virus titering. TIGIT-GFP adenovirus was characterized by flow cytometry and immunofluorescence, and its expression in mouse liver was detected by infection through caudal vein injection. The results showed the successful construction of the TIGIT-GFP adenovirus (5 x 10(10) PFU/mL). Co-expression of TIGIT and GFP was identified in 293A and liver cells; synthesis and positioning of TIGIT-GFP was viewed under a fluorescence microscope. TIGIT-GFP was highly expressed on liver cells 1 day (25.53%) after infection and faded 3 days (11.36%) after injection. In conclusion, the fusion of TIGIT with GFP allows easy, rapid, and uncomplicated detection of TIGIT translation. The construction of a TIGIT-GFP adenovirus, mediating TIGIT expression in vitro and in vivo, lays the foundation for further research into TIGIT function and gene therapy. Moreover, the TIGIT-GFP adenovirus is a helpful tool for studying other proteins (which could replace the TIGIT gene).

  2. Functional Coding Variation in Recombinant Inbred Mouse Lines Reveals Novel Serotonin Transporter-Associated Phenotypes

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Ana [Vanderbilt University; Airey, David [University of Tennessee Health Science Center, Memphis; Thompson, Brent [Vanderbilt University; Zhu, C [Vanderbilt University; Rinchik, Eugene M [ORNL; Lu, Lu [University of Tennessee Health Science Center, Memphis; Chesler, Elissa J [ORNL; Erikson, Keith [University of North Carolina; Blakely, Randy [Vanderbilt University

    2009-01-01

    The human serotonin (5-hydroxytryptamine, 5-HT) transporter (hSERT, SLC6A4) figures prominently in the etiology or treatment of many prevalent neurobehavioral disorders including anxiety, alcoholism, depression, autism and obsessive-compulsive disorder (OCD). Here we utilize naturally occurring polymorphisms in recombinant inbred (RI) lines to identify novel phenotypes associated with altered SERT function. The widely used mouse strain C57BL/6J, harbors a SERT haplotype defined by two nonsynonymous coding variants (Gly39 and Lys152 (GK)). At these positions, many other mouse lines, including DBA/2J, encode Glu39 and Arg152 (ER haplotype), assignments found also in hSERT. Synaptosomal 5-HT transport studies revealed reduced uptake associated with the GK variant. Heterologous expression studies confirmed a reduced SERT turnover rate for the GK variant. Experimental and in silico approaches using RI lines (C57Bl/6J X DBA/2J=BXD) identifies multiple anatomical, biochemical and behavioral phenotypes specifically impacted by GK/ER variation. Among our findings are multiple traits associated with anxiety and alcohol consumption, as well as of the control of dopamine (DA) signaling. Further bioinformatic analysis of BXD phenotypes, combined with biochemical evaluation of SERT knockout mice, nominates SERT-dependent 5-HT signaling as a major determinant of midbrain iron homeostasis that, in turn, dictates ironregulated DA phenotypes. Our studies provide a novel example of the power of coordinated in vitro, in vivo and in silico approaches using murine RI lines to elucidate and quantify the system-level impact of gene variation.

  3. Automated microinjection of recombinant BCL-X into mouse zygotes enhances embryo development.

    Science.gov (United States)

    Liu, Xinyu; Fernandes, Roxanne; Gertsenstein, Marina; Perumalsamy, Alagammal; Lai, Ingrid; Chi, Maggie; Moley, Kelle H; Greenblatt, Ellen; Jurisica, Igor; Casper, Robert F; Sun, Yu; Jurisicova, Andrea

    2011-01-01

    Progression of fertilized mammalian oocytes through cleavage, blastocyst formation and implantation depends on successful implementation of the developmental program, which becomes established during oogenesis. The identification of ooplasmic factors, which are responsible for successful embryo development, is thus crucial in designing possible molecular therapies for infertility intervention. However, systematic evaluation of molecular targets has been hampered by the lack of techniques for efficient delivery of molecules into embryos. We have developed an automated robotic microinjection system for delivering cell impermeable compounds into preimplantation embryos with a high post-injection survival rate. In this paper, we report the performance of the system on microinjection of mouse embryos. Furthermore, using this system we provide the first evidence that recombinant BCL-XL (recBCL-XL) protein is effective in preventing early embryo arrest imposed by suboptimal culture environment. We demonstrate that microinjection of recBCL-XL protein into early-stage embryos repairs mitochondrial bioenergetics, prevents reactive oxygen species (ROS) accumulation, and enhances preimplantation embryo development. This approach may lead to a possible treatment option for patients with repeated in vitro fertilization (IVF) failure due to poor embryo quality.

  4. Automated microinjection of recombinant BCL-X into mouse zygotes enhances embryo development.

    Directory of Open Access Journals (Sweden)

    Xinyu Liu

    Full Text Available Progression of fertilized mammalian oocytes through cleavage, blastocyst formation and implantation depends on successful implementation of the developmental program, which becomes established during oogenesis. The identification of ooplasmic factors, which are responsible for successful embryo development, is thus crucial in designing possible molecular therapies for infertility intervention. However, systematic evaluation of molecular targets has been hampered by the lack of techniques for efficient delivery of molecules into embryos. We have developed an automated robotic microinjection system for delivering cell impermeable compounds into preimplantation embryos with a high post-injection survival rate. In this paper, we report the performance of the system on microinjection of mouse embryos. Furthermore, using this system we provide the first evidence that recombinant BCL-XL (recBCL-XL protein is effective in preventing early embryo arrest imposed by suboptimal culture environment. We demonstrate that microinjection of recBCL-XL protein into early-stage embryos repairs mitochondrial bioenergetics, prevents reactive oxygen species (ROS accumulation, and enhances preimplantation embryo development. This approach may lead to a possible treatment option for patients with repeated in vitro fertilization (IVF failure due to poor embryo quality.

  5. Recombinant fetuin-B protein maintains high fertilization rate in cumulus cell-free mouse oocytes.

    Science.gov (United States)

    Dietzel, E; Floehr, J; Van de Leur, E; Weiskirchen, R; Jahnen-Dechent, W

    2017-01-01

    Does fetuin-B inhibit premature zona pellucida (ZP) hardening in mouse oocytes in vitro and thus increase IVF rate? Supplementation of oocyte in vitro maturation (IVM) media with recombinant mouse fetuin-B (rmFetuB) increased fertilization rate without affecting mouse embryo development into blastocysts. Mice deficient in fetuin-B are infertile owing to premature ZP hardening. Premature ZP hardening also occurs during oocyte IVM leading to decreased fertilization rate. We fertilized batches of 20-30 mouse metaphase II (Mll) stage oocytes from C57BL/6 mice with fresh sperm, and studied early embryo development until blastocyst hatching. Oocytes were maintained with or without rmFetuB during IVM and IVF. Exogenous rmFetuB was added to media prior to oocyte isolation. ZP hardening was quantified by chymotrypsin digestion timing and by counting attached sperm. In the absence of cumulus cells, rmFetuB dose-dependently inhibited ZP hardening and increased IVF rate (P = 0.039). Fetuin-B at ≥0.03 mg/ml also inhibited physiological, fertilization-triggered ZP hardening (indicated by increased sperm binding, P = 0.0002), without increasing embryo death. Exogenous rmFetuB increased IVF rate for up to 5 hours of IVM (P = 0.02 at 1 hour, P = 0.01 at 5 hours of IVM). Mll stage oocytes in this study were isolated from the ampullae of fetuin-B expressing mice. Thus, oocytes were protected against premature ZP hardening by endogenous fetuin-B. In humans and livestock, oocytes are usually isolated by follicle puncture before ovulation. In this situation, the deprivation of endogenous fetuin-B would occur earlier and the effect of exogenous fetuin-B in the IVF medium may be even more pronounced. Fertilization-triggered ZP hardening is essential for embryo development but in this study the effect of fetuin-B supplementation was only studied to blastocyst stage. Any influence of added fetuin-B on later embryo development after transplantation remains to be determined. The astacin

  6. Recombinant tissue plasminogen activator enhances microparticle release from mouse brain-derived endothelial cells through plasmin.

    Science.gov (United States)

    Garraud, Marie; Khacef, Kahina; Vion, Anne-Clémence; Leconte, Claire; Yin, Min; Renard, Jean-Marie; Marchand-Leroux, Catherine; Boulanger, Chantal M; Margaill, Isabelle; Beray-Berthat, Virginie

    2016-11-15

    Thrombolysis with recombinant tissue plasminogen activator (rt-PA) is currently the only approved pharmacological strategy for acute ischemic stroke. However, rt-PA exhibits vascular toxicity mainly due to endothelial damage. To investigate the mechanisms underlying rt-PA-induced endothelial alterations, we assessed the role of rt-PA in the generation of endothelial microparticles (EMPs), emerging biological markers and effectors of endothelial dysfunction. The mouse brain-derived endothelial cell line bEnd.3 was used. Cells were treated with rt-PA at 20, 40 or 80μg/ml for 15 or 24h, and EMPs were quantified in the culture media using Annexin-V staining coupled with flow cytometry. Rt-PA enhanced EMP release from bEnd.3 cells with a maximal increase at the 40μg/ml dose for 24h (+78% compared to controls). Using tranexamic acid and aprotinin we demonstrated that plasmin is responsible for rt-PA-induced EMP release. The p38 MAPK inhibitor SB203580 and the poly(ADP-ribose)polymerase (PARP) inhibitor PJ34 also reduced rt-PA-induced EMP production, suggesting that p38 MAPK and PARP are downstream intracellular effectors of rt-PA/plasmin. Rt-PA also altered through plasmin the morphology and the confluence of bEnd.3 cells. By contrast, these changes did not implicate p38 MAPK and PARP. This study demonstrates that rt-PA induces the production of microparticles by cerebral endothelial cells, through plasmin, p38 MAPK and PARP pathways. Determining the phenotype of these EMPs to clarify their role on the endothelium in ischemic conditions could thus be of particular interest. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Recombinant erythroid differentiation regulator 1 inhibits both inflammation and angiogenesis in a mouse model of rosacea.

    Science.gov (United States)

    Kim, Miri; Kim, Kyung-Eun; Jung, Haw Young; Jo, Hyunmu; Jeong, Seo-Won; Lee, Jahyung; Kim, Chang Han; Kim, Heejong; Cho, Daeho; Park, Hyun Jeong

    2015-09-01

    The erythroid differentiation regulator 1 (Erdr1), which is a novel and highly conserved factor, was recently reported to be negatively regulated by IL-18 and to play a crucial role as an antimetastatic factor. IL-18 is a proinflammatory cytokine that functions as an angiogenic mediator in inflammation. Rosacea is a chronic inflammatory skin disorder that is characterized by abnormal inflammation and vascular hyperactivity of the facial skin. To determine whether Erdr1 contributes to the regulation of the chronic inflammatory process in the development of rosacea, an immunohistochemical analysis was performed in healthy donors and patients with rosacea. In this study, we showed that Erdr1 was downregulated, whereas IL-18 was upregulated, in patients with rosacea, which led us to question the role of Erdr1 in this disorder. Moreover, a rosacea-like BALB/c mouse model was used to determine the role of Erdr1 in rosacea in vivo. LL-37 injection induced typical rosacea features, including erythema, telangiectasia and inflammation. Treatment with recombinant Erdr1 (rErdr1) resulted in a significant reduction of erythema, inflammatory cell infiltration (including CD4(+) and CD8(+) T cells), and microvessel density with vascular endothelial growth factor (VEGF). Taken together, our findings suggest that rErdr1 may be involved in attenuating the inflammation and angiogenesis associated with the pathogenesis of rosacea. Thus, these results provide new insight into the mechanism involved in this condition and indicate that rErdr1 could be a potential target for therapeutic intervention of rosacea. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. A Nestin-cre transgenic mouse is insufficient for recombination in early embryonic neural progenitors

    Directory of Open Access Journals (Sweden)

    Huixuan Liang

    2012-09-01

    Nestin-cre transgenic mice have been widely used to direct recombination to neural stem cells (NSCs and intermediate neural progenitor cells (NPCs. Here we report that a readily utilized, and the only commercially available, Nestin-cre line is insufficient for directing recombination in early embryonic NSCs and NPCs. Analysis of recombination efficiency in multiple cre-dependent reporters and a genetic mosaic line revealed consistent temporal and spatial patterns of recombination in NSCs and NPCs. For comparison we utilized a knock-in Emx1cre line and found robust recombination in NSCs and NPCs in ventricular and subventricular zones of the cerebral cortices as early as embryonic day 12.5. In addition we found that the rate of Nestin-cre driven recombination only reaches sufficiently high levels in NSCs and NPCs during late embryonic and early postnatal periods. These findings are important when commercially available cre lines are considered for directing recombination to embryonic NSCs and NPCs.

  9. A pink mouse reports the switch from red to green fluorescence upon Cre-mediated recombination

    OpenAIRE

    Hartwich Heiner; Satheesh Somisetty V; Nothwang Hans

    2012-01-01

    Abstract Background Targeted genetic modification in the mouse becomes increasingly important in biomedical and basic science. This goal is most often achieved by use of the Cre/loxP system and numerous Cre-driver mouse lines are currently generated. Their initial characterization requires reporter mouse lines to study the in vivo spatiotemporal activity of Cre. Findings Here, we report a dual fluorescence reporter mouse line, which switches expression from the red fluorescent protein mCherry...

  10. Cycloheximide induces expression of the human interferon beta 1 gene in mouse cells transformed by bovine papillomavirus-interferon beta 1 recombinants.

    OpenAIRE

    Maroteaux, L; Chen, L.; Mitrani-Rosenbaum, S; Howley, P M; Revel, M

    1983-01-01

    Mouse cells transformed by a bovine papillomavirus recombinant vector containing the human interferon (IFN) beta 1 (IFN-beta 1) gene could be induced to produce human as well as mouse IFNs. The optimal conditions for induction of human IFN and of its mRNA in these transformants resembled those needed for mouse IFN: high concentrations of DEAE-dextran and low concentrations of polyriboinosinic acid-polyribocytidylic acid. Superinduction by inhibitors of protein synthesis which strongly stimula...

  11. A multifunctional teal-fluorescent Rosa26 reporter mouse line for Cre- and Flp-mediated recombination.

    Science.gov (United States)

    Imayoshi, Itaru; Hirano, Kyoko; Sakamoto, Masayuki; Miyoshi, Goichi; Imura, Tetsuya; Kitano, Satsuki; Miyachi, Hitoshi; Kageyama, Ryoichiro

    2012-05-01

    Reporters of Cre and/or Flp activity are important for defining the spatial and temporal extent of Cre/Flp-mediated recombination. Here, we describe R26-CAG-LF-mTFP1, a multifunctional fluorescent reporter mouse that strongly expresses mTFP1 (bright teal fluorescent protein) after Cre- and Flp-mediated recombination. To meet the need for single recombinase-mediated reporter expression, we generated derivatives of R26-CAG-LF-mTFP1. The germline excision of the Frt-flanked stop cassette in R26-CAG-LF-mTFP1 generated a Cre-dependent reporter (R26-CAG-LoxP-mTFP1). Similarly, R26-CAG-FRT-mTFP1, in which the loxP-flanked stop cassette was excised in the germline, requires only Flp to activate mTFP1 expression. Copyright © 2012 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  12. Recombinant vascular endothelial growth factor 121 injection for the prevention of fetal growth restriction in a preeclampsia mouse model.

    Science.gov (United States)

    Sulistyowati, Sri; Bachnas, Muhammad Adrianes; Anggraini, Nuri Dyah; Yuliantara, Eric Edwin; Prabowo, Wisnu; Anggraini, Nutria Widya Purna; Pramono, Mochammad Besari Adi; Adityawarman; Dachlan, Erry Gumilar; Andonotopo, Wiku

    2017-02-01

    To discover the potential role of recombinant VEGF121 (rVEGF121) injection for the prevention of fetal growth restriction in a preeclampsia (PE) mouse model (Mus musculus). This is an experimental study of 30 pregnant mice that were randomly divided into three groups: normal, PE, and PE with rVEGF121 injection. The PE mouse model was created by injecting anti Qa-2 10 ng iv, which is deleterious to Qa-2 expression (homologous to HLA-G), from the first to the fourth day of gestation. PE was validated by measuring serum levels of soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor(PIGF) and also by kidney histopathology. Recombinant VEGF121 was given on the ninth day until the 11th day of pregnancy; mice were terminated on the 16th day. Fetal weights were acquired with a Denver analytical balance. Serum levels of sFlt-1 and PlGF were measured using enzyme-linked immunosorbent assay (ELISA). The data were statistically analyzed via analysis of variance (ANOVA). On average, fetal birth weight was 0.7150 g in the normal group, 0.4936 g in the PE group, and 0.6768 g in the PE with rVEGF121 injection group. ANOVA showed significant growth restriction in the PE group (P=0.006), confirming the use of anti Qa-2 as a suitable PE model. Kidney histopathology results, sFlt-1 levels, and PlGF levels also demonstrated that anti Qa-2 consistently conferred hallmarks of PE in mice. Vascular endothelial growth factor (VEGF) injection prevented fetal growth restriction; comparable fetal weights were observed between the PE model with VEGF treatment and the normal group (P=0.610) but differed from the untreated PE group (P=0.021). Injection of rVEGF121 has the potential to prevent fetal growth restriction in a newly proposed PE mouse model.

  13. Assessment of tropism and effectiveness of new primate-derived hybrid recombinant AAV serotypes in the mouse and primate retina.

    Science.gov (United States)

    Charbel Issa, Peter; De Silva, Samantha R; Lipinski, Daniel M; Singh, Mandeep S; Mouravlev, Alexandre; You, Qisheng; Barnard, Alun R; Hankins, Mark W; During, Matthew J; Maclaren, Robert E

    2013-01-01

    Adeno-associated viral vectors (AAV) have been shown to be safe in the treatment of retinal degenerations in clinical trials. Thus, improving the efficiency of viral gene delivery has become increasingly important to increase the success of clinical trials. In this study, structural domains of different rAAV serotypes isolated from primate brain were combined to create novel hybrid recombinant AAV serotypes, rAAV2/rec2 and rAAV2/rec3. The efficacy of these novel serotypes were assessed in wild type mice and in two models of retinal degeneration (the Abca4(-/-) mouse which is a model for Stargardt disease and in the Pde6b(rd1/rd1) mouse) in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette. We show that these novel hybrid serotypes can transduce retinal tissue in mice and primates efficiently, although no more than AAV2/2 and rAAV2/5 serotypes. Transduction efficiency appeared lower in the Abca4(-/-) mouse compared to wild type with all vectors tested, suggesting an effect of specific retinal diseases on the efficiency of gene delivery. Shuffling of AAV capsid domains may have clinical applications for patients who develop T-cell immune responses following AAV gene therapy, as specific peptide antigen sequences could be substituted using this technique prior to vector re-treatments.

  14. Assessment of tropism and effectiveness of new primate-derived hybrid recombinant AAV serotypes in the mouse and primate retina.

    Directory of Open Access Journals (Sweden)

    Peter Charbel Issa

    Full Text Available Adeno-associated viral vectors (AAV have been shown to be safe in the treatment of retinal degenerations in clinical trials. Thus, improving the efficiency of viral gene delivery has become increasingly important to increase the success of clinical trials. In this study, structural domains of different rAAV serotypes isolated from primate brain were combined to create novel hybrid recombinant AAV serotypes, rAAV2/rec2 and rAAV2/rec3. The efficacy of these novel serotypes were assessed in wild type mice and in two models of retinal degeneration (the Abca4(-/- mouse which is a model for Stargardt disease and in the Pde6b(rd1/rd1 mouse in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette. We show that these novel hybrid serotypes can transduce retinal tissue in mice and primates efficiently, although no more than AAV2/2 and rAAV2/5 serotypes. Transduction efficiency appeared lower in the Abca4(-/- mouse compared to wild type with all vectors tested, suggesting an effect of specific retinal diseases on the efficiency of gene delivery. Shuffling of AAV capsid domains may have clinical applications for patients who develop T-cell immune responses following AAV gene therapy, as specific peptide antigen sequences could be substituted using this technique prior to vector re-treatments.

  15. BLM has early and late functions in homologous recombination repair in mouse embryonic stem cells

    DEFF Research Database (Denmark)

    Chu, W K; Hanada, K; Kanaar, R

    2010-01-01

    BLM is a RecQ family helicase that is defective in individuals with the cancer predisposition disorder, Bloom's syndrome (BS). At the cellular level, BS is characterized by hyper-recombination manifested as excessive sister chromatid exchange and loss of heterozygosity. However, the precise...... function of BLM remains unclear. Multiple roles have been proposed for BLM in the homologous recombination (HR) repair pathway, including 'early' functions, such as the stimulation of resection of DNA double-strand break ends or displacement of the invading strand of DNA displacement loops, and 'late...

  16. A modified immune tolerant mouse model to study the immunogenicity of recombinant human interferon beta

    NARCIS (Netherlands)

    Abdolvahab, Mohadeseh Haji; Brinks, Vera; Schellekens, Huub

    2014-01-01

    Interferon beta may induce antibodies in multiple sclerosis patients and the incidence of immunogenicity depends on the type of product. These antibodies can reduce the efficacy of interferon beta. Two transgenic immune tolerant mouse models for human interferon beta (hIFNβ) (C57Bl/6, and

  17. Mouse Sycp1 functions in synaptonemal complex assembly, meiotic recombination., and XY body formation

    NARCIS (Netherlands)

    Vries, de F.A.T.; Boer, de E.; Bosch, M.; Baarends, W.M.; Ooms, M.; Yuan, L.; Liu, J.G.; Zeeland, van A.A.; Heyting, C.; Pastink, A.

    2005-01-01

    In meiotic prophase, synaptonemal complexes (SCs) closely appose homologous chromosomes (homologs) along their length. SCs are assembled from two axial elements (AEs), one along each homolog, which are connected by numerous transverse filaments (TFs). We disrupted the mouse gene encoding TF protein

  18. Higher differentiation among subspecies of the house mouse (Mus musculus) in genomic regions with low recombination.

    Science.gov (United States)

    Geraldes, A; Basset, P; Smith, K L; Nachman, M W

    2011-11-01

    In the early stages of reproductive isolation, genomic regions of reduced recombination are expected to show greater levels of differentiation, either because gene flow between species is reduced in these regions or because the effects of selection at linked sites within species are enhanced in these regions. Here, we study the patterns of DNA sequence variation at 27 autosomal loci among populations of Mus musculus musculus, M. m. domesticus, and M. m. castaneus, three subspecies of house mice with collinear genomes. We found that some loci exhibit considerable shared variation among subspecies, while others exhibit fixed differences. We used an isolation-with-gene-flow model to estimate divergence times and effective population sizes (N(e) ) and to disentangle ancestral variation from gene flow. Estimates of divergence time indicate that all three subspecies diverged from one another within a very short period of time approximately 350,000 years ago. Overall, N(e) for each subspecies was associated with the degree of genetic differentiation: M. m. musculus had the smallest N(e) and the greatest proportion of monophyletic gene genealogies, while M. m. castaneus had the largest N(e) and the smallest proportion of monophyletic gene genealogies. M. m. domesticus and M. m. musculus were more differentiated from each other than either were from M. m. castaneus, consistent with greater reproductive isolation between M. m. domesticus and M. m. musculus. F(ST) was significantly greater at loci experiencing low recombination rates compared to loci experiencing high recombination rates in comparisons between M. m. castaneus and M. m. musculus or M. m. domesticus. These results provide evidence that genomic regions with less recombination show greater differentiation, even in the absence of chromosomal rearrangements. © 2011 Blackwell Publishing Ltd.

  19. Recombinant Adeno-Associated Virus-Mediated microRNA Delivery into the Postnatal Mouse Brain Reveals a Role for miR-134 in Dendritogenesis in Vivo

    DEFF Research Database (Denmark)

    Christensen, Mette; Larsen, Lars A; Kauppinen, Sakari

    2010-01-01

    delivery of microRNAs in vivo by use of recombinant adeno-associated virus (rAAV). rAAV-mediated overexpression of miR-134 in neurons of the postnatal mouse brain provided evidence for a negative role of miR-134 in dendritic arborization of cortical layer V pyramidal neurons in vivo, thereby confirming...

  20. Genotype versus phenotype: conflicting results in mapping a lung tumor susceptibility locus to the G7c recombination interval in the mouse MHC class III region

    NARCIS (Netherlands)

    van Kooij, M.; de Groot, K.; van Vugt, H.; Aten, J.; Snoek, M.

    2001-01-01

    Susceptibility to chemically induced lung tumorigenesis has previously been mapped to a genomic interval of 27 kb in the MHC class III region of the mouse using two H2 (a/b) intra- H2 recombinants, B10.A(1R) and B10.A(2R). Three genes are located within this interval, G7e (encoding a viral envelope

  1. Evaluation of Recombinant Multi-Epitope Outer Membrane Protein-Based Klebsiella pneumoniae Subunit Vaccine in Mouse Model

    Directory of Open Access Journals (Sweden)

    Litty Babu

    2017-09-01

    Full Text Available Safety and protective efficacy of recombinant multi-epitope subunit vaccine (r-AK36 was evaluated in a mouse model. Recombinant AK36 protein comprised of immunodominant antigens from outer membrane proteins (Omp’s of Klebsiella pneumoniae namely OmpA and OmpK36. r-AK36 was highly immunogenic and the hyperimmune sera reacted strongly with native OmpA and OmpK36 proteins from different K. pneumoniae strains. Hyperimmune sera showed cross-reactivity with Omp’s of other Gram-negative organisms. Humoral responses showed a Th2-type polarized immune response with IgG1 being the predominant antibody isotype. Anti-r-AK36 antibodies showed antimicrobial effect during in vitro testing with MIC values in the range of 25–50 μg/ml on different K. pneumoniae strains. The recombinant antigen elicited three fold higher proliferation of splenocytes from immunized mice compared to those with sham-immunized mice. Anti-r-AK36 antibodies also exhibited in vitro biofilm inhibition property. Subunit vaccine r-AK36 immunization promoted induction of protective cytokines IL-2 and IFN-γ in immunized mice. When r-AK36-immunized mice were challenged with 3 × LD100 dose, ∼80% of mice survived beyond the observation period. Passive antibody administration to naive mice protected them (67% against the lethal challenge. Since the targeted OMPs are conserved among all K. pneumoniae serovars and due to the strong nature of immune responses, r-AK36 subunit vaccine could be a cost effective candidate against klebsiellosis.

  2. Establishment of an osteogenic cell line derived from adult mouse bone marrow stroma by use of a recombinant retrovirus.

    Science.gov (United States)

    Mathieu, E; Schoeters, G; vander Plaetse, F; Merregaert, J

    1992-04-01

    In order to characterize fibroblastic colony-forming units (CFU-F) from murine bone marrow in relation to osteogenesis, adherent cells of 7-day-old BALB/c mouse bone marrow cultures were infected with a recombinant retrovirus (N2/ delta fosB) containing the bacterial neomycin resistance gene. One of the G418-resistant clones, MN7, was selected for further analysis on the basis of its high expression of the bone-specific alkaline phosphatase. The cells have now been in culture for more than 1 year and maintain a stable phenotype. The osteogenic nature of the immortalized clone MN7 was demonstrated as follows: (1) Mineralization was detected by 85Sr uptake and with the Von Kossa staining method only after in vitro cultivation on a collagen type I matrix. (2) Osteoblastic phenotype markers, including the synthesis of type I collagen, osteonectin, and the bone-specific isoenzyme of alkaline phosphatase were expressed in vitro. (3) MN7 cells responded to bone effectors such as parathyroid hormone and 1,25-dihydroxyvitamin D3. (4) Intraperitoneal injection of MN7 cells into 1-day-old BALB/c mice produced typical osteosarcomas in all animals. We conclude that MN7, derived entirely in vitro from a stromal CFU-F colony, represents a stable murine osteosarcoma cell line expressing the osteoblastic phenotype and provides the first direct evidence needed to establish adult mouse marrow-derived, nonhematopoietic stromal cells as osteoprogenitors.

  3. Effects of exogenous recombinant APC in mouse models of ischemia reperfusion injury and of atherosclerosis.

    Directory of Open Access Journals (Sweden)

    Karin C A A Wildhagen

    Full Text Available Activated protein C (APC is a serine protease that has both anticoagulant and cytoprotective properties. The cytoprotective effects are protease activated receptor 1 (PAR-1 and endothelial protein C receptor (EPCR dependent and likely underlie protective effects of APC in animal models of sepsis, myocardial infarction and ischemic stroke. S360A-(APC, a variant (APC that has no catalytic activity, binds EPCR and shifts pro-inflammatory signaling of the thrombin-PAR-1 complex to anti-inflammatory signaling. In this study we investigated effects of human (hwt-PC, hS360A-PC, hwt-APC and hS360A-APC in acute (mouse model of acute myocardial ischemia/reperfusion (I/R injury and chronic inflammation (apoE-/- mouse model of atherosclerosis. All h(APC variants significantly reduced myocardial infarct area (p<0.05 following I/R injury. IL-6 levels in heart homogenates did not differ significantly between sham, placebo and treatment groups in I/R injury. None of the h(APC variants decreased number and size of atherosclerotic plaques in apoE-/- mice. Only hS360A-APC slightly affected phenotype of plaques. IL-6 levels in plasma were significantly (p<0.001 decreased in hwt-APC and hS360A-PC treated mice. In the last group levels of monocyte chemotactic protein 1 (MCP-1 were significantly increased (p<0.05. In this study we show that both hwt and hS360A-(APC protect against acute myocardial I/R injury, which implies that protection from I/R injury is independent of the proteolytic activity of APC. However, in the chronic atherosclerosis model hwt and hS360-(APC had only minor effects. When the dose, species and mode of (APC administration will be adjusted, we believe that (APC will have potential to influence development of chronic inflammation as occurring during atherosclerosis as well.

  4. Enhanced alcohol self-administration and reinstatement in a highly impulsive, inattentive recombinant inbred mouse strain

    Directory of Open Access Journals (Sweden)

    Maarten eLoos

    2013-10-01

    Full Text Available Deficits in executive control have frequently been associated with alcohol use disorder. Here we investigated to what extent pre-existing genetically encoded levels of impulsive/inattentive behavior associate with motivation to take alcohol and vulnerability to cue-induced reinstatement of alcohol seeking in an operant self-administration paradigm. We took advantage of BXD16, a recombinant inbred strain previously shown to have enhanced impulsivity and poor attentional control. We compared BXD16 with C57BL/6J mice in a simple choice reaction time task (SCRTT and confirmed its impulsive/inattentive phenotype. BXD16 mice were less active in a novel open field, and were equally active in an automated home cage environment, showing that increased impulsive responding of BXD16 mice could not be explained by enhanced general activity compared to C57BL/6J mice. After training in a sucrose/alcohol fading self-administration procedure, BXD16 showed increased motivation to earn 10% alcohol solution, both under fixed ratio (FR1 and progressive ratio (PR2 schedules of reinforcement. Responding on the active lever readily decreased during extinction training with no apparent differences between strains. However, upon re-exposure to alcohol-associated cues, alcohol seeking was reinstated to a larger extent in BXD16 than in C57BL/6J mice. Although further studies are needed to determine whether impulsivity/inattention and alcohol seeking depend on common or separate genetic loci, these data show that in mice enhanced impulsivity coincides with increased motivation to take alcohol, as well as relapse vulnerability.

  5. Human recombinant arginase enzyme reduces plasma arginine in mouse models of arginase deficiency.

    Science.gov (United States)

    Burrage, Lindsay C; Sun, Qin; Elsea, Sarah H; Jiang, Ming-Ming; Nagamani, Sandesh C S; Frankel, Arthur E; Stone, Everett; Alters, Susan E; Johnson, Dale E; Rowlinson, Scott W; Georgiou, George; Lee, Brendan H

    2015-11-15

    Arginase deficiency is caused by deficiency of arginase 1 (ARG1), a urea cycle enzyme that converts arginine to ornithine. Clinical features of arginase deficiency include elevated plasma arginine levels, spastic diplegia, intellectual disability, seizures and growth deficiency. Unlike other urea cycle disorders, recurrent hyperammonemia is typically less severe in this disorder. Normalization of plasma arginine levels is the consensus treatment goal, because elevations of arginine and its metabolites are suspected to contribute to the neurologic features. Using data from patients enrolled in a natural history study conducted by the Urea Cycle Disorders Consortium, we found that 97% of plasma arginine levels in subjects with arginase deficiency were above the normal range despite conventional treatment. Recently, arginine-degrading enzymes have been used to deplete arginine as a therapeutic strategy in cancer. We tested whether one of these enzymes, a pegylated human recombinant arginase 1 (AEB1102), reduces plasma arginine in murine models of arginase deficiency. In neonatal and adult mice with arginase deficiency, AEB1102 reduced the plasma arginine after single and repeated doses. However, survival did not improve likely, because this pegylated enzyme does not enter hepatocytes and does not improve hyperammonemia that accounts for lethality. Although murine models required dosing every 48 h, studies in cynomolgus monkeys indicate that less frequent dosing may be possible in patients. Given that elevated plasma arginine rather than hyperammonemia is the major treatment challenge, we propose that AEB1102 may have therapeutic potential as an arginine-reducing agent in patients with arginase deficiency. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Milligram quantities of homogeneous recombinant full-length mouse Munc18c from Escherichia coli cultures.

    Directory of Open Access Journals (Sweden)

    Asma Rehman

    Full Text Available Vesicle fusion is an indispensable cellular process required for eukaryotic cargo delivery. The Sec/Munc18 protein Munc18c is essential for insulin-regulated trafficking of glucose transporter4 (GLUT4 vesicles to the cell surface in muscle and adipose tissue. Previously, our biophysical and structural studies have used Munc18c expressed in SF9 insect cells. However to maximize efficiency, minimize cost and negate any possible effects of post-translational modifications of Munc18c, we investigated the use of Escherichia coli as an expression host for Munc18c. We were encouraged by previous reports describing Munc18c production in E. coli cultures for use in in vitro fusion assay, pulldown assays and immunoprecipitations. Our approach differs from the previously reported method in that it uses a codon-optimized gene, lower temperature expression and autoinduction media. Three N-terminal His-tagged constructs were engineered, two with a tobacco etch virus (TEV or thrombin protease cleavage site to enable removal of the fusion tag. The optimized protocol generated 1-2 mg of purified Munc18c per L of culture at much reduced cost compared to Munc18c generated using insect cell culture. The purified recombinant Munc18c protein expressed in bacteria was monodisperse, monomeric, and functional. In summary, we developed methods that decrease the cost and time required to generate functional Munc18c compared with previous insect cell protocols, and which generates sufficient purified protein for structural and biophysical studies.

  7. Chaperone-mediated gene therapy with recombinant AAV-PPCA in a new mouse model of type I sialidosis.

    Science.gov (United States)

    Bonten, Erik J; Yogalingam, Gouri; Hu, Huimin; Gomero, Elida; van de Vlekkert, Diantha; d'Azzo, Alessandra

    2013-10-01

    The lysosomal storage disease sialidosis is caused by a primary deficiency of the sialidase N-acetyl-α-neuraminidase-1 (NEU1). Patients with type I sialidosis develop an attenuated, non-neuropathic form of the disease also named cherry red spot myoclonus syndrome, with symptoms arising during juvenile/ adult age. NEU1 requires binding to its chaperone, protective protein/cathepsin A (PPCA), for lysosomal compartmentalization, stability and catalytic activation. We have generated a new mouse model of type I sialidosis that ubiquitously expresses a NEU1 variant carrying a V54M amino acid substitution identified in an adult patient with type I sialidosis. Mutant mice developed signs of lysosomal disease after 1year of age, predominantly in the kidney, albeit low residual NEU1 activity was detected in most organs and cell types. We demonstrate that the activity of the mutant enzyme could be effectively increased in all systemic tissues by chaperone-mediated gene therapy with a liver-tropic recombinant AAV2/8 vector expressing PPCA. This resulted in clear amelioration of the disease phenotype. These results suggest that at least some of the NEU1 mutations associated with type I sialidosis may respond to PPCA-chaperone-mediated gene therapy. Published by Elsevier B.V.

  8. Chaperone–Mediated Gene Therapy with Recombinant AAV-PPCA in a New Mouse Model of Type I Sialidosis

    Science.gov (United States)

    Bonten, Erik J.; Yogalingam, Gouri; Hu, Huimin; Gomero, Elida; van de Vlekkert, Diantha; d’Azzo, Alessandra

    2013-01-01

    The lysosomal storage disease sialidosis is caused by a primary deficiency of the sialidase NEU1. Patients with type I sialidosis develop an attenuated, non-neuropathic form of the disease also named cherry red spot myoclonus syndrome, with symptoms arising during juvenile/ adult age. NEU1 requires binding to its chaperone, protective protein/cathepsin A (PPCA), for lysosomal compartmentalization, stability and catalytic activation. We have generated a new mouse model of type I sialidosis that ubiquitously expresses a NEU1 variant carrying a V54M amino acid substitution identified in an adult patient with type I sialidosis. Mutant mice developed signs of lysosomal disease after 1 year of age, predominantly in the kidney, albeit low residual NEU1 activity was detected in most organs and cell types. We demonstrate that the activity of the mutant enzyme could be effectively increased in all systemic tissues by chaperone–mediated gene therapy with a liver-tropic recombinant AAV2/8 vector expressing PPCA. This resulted in clear amelioration of the disease phenotype. These results suggest that at least some of the NEU1 mutations associated with type I sialidosis may respond to PPCA-chaperone-mediated gene therapy. PMID:23770387

  9. Recombinant N-terminal nucleotide-binding domain from mouse P-glycoprotein. Overexpression, purification, and role of cysteine 430.

    Science.gov (United States)

    Dayan, G; Baubichon-Cortay, H; Jault, J M; Cortay, J C; Deléage, G; Di Pietro, A

    1996-05-17

    Varying length cDNAs encoding the N-terminal nucleotide-binding domain (NBD1) from mouse mdr1 P-glyco- protein were prepared on the basis of structure predictions. Corresponding recombinant proteins were overexpressed in Escherichia coli, and the shortest one containing amino acids 395-581 exhibited the highest solubility. Insertion of an N-terminal hexahistidine tag allowed domain purification by nickel-chelate affinity chromatography. NBD1 efficiently interacted with nucleotides. Fluorescence methods showed that ATP bound at millimolar concentrations and its 2',3'-O-(2,4,6-trinitrophenyl) derivative at micromolar concentrations, while the 2'(3')-N-methylanthraniloyl derivative had intermediate affinity. Photoaffinity labeling was achieved upon irradiation with 8-azido-ATP. The domain exhibited ATPase activity with a Km for MgATP in the millimolar range, and ATP hydrolysis was competitively inhibited by micromolar 2',3'-O-(2,4,6-trinitrophenyl)-ATP. NBD1 contained a single cysteine residue, at position 430, that was derivatized with radiolabeled N-ethylmaleimide. Cysteine modification increased 6-fold the Kd for 2'(3')-N-methylanthraniloyl-ATP and prevented 8-azido-ATP photolabeling. ATPase activity was inhibited with a 5-fold increase in the Km for MgATP. The results suggest that chemical modification of Cys-430 is involved in the N-ethylmaleimide inhibition of whole P-glycoprotein by altering substrate interaction.

  10. Immunization with Recombinant TcdB-Encapsulated Nanocomplex Induces Protection against Clostridium difficile Challenge in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Yi-Wen Liu

    2017-07-01

    Full Text Available Clostridium difficile is considered to be one of the major cause of infectious diarrhea in healthcare systems worldwide. Symptoms of C. difficile infection are caused largely by the production of two cytotoxins: toxin A (TcdA and toxin B (TcdB. Vaccine development is considered desirable as it would decrease the mounting medical costs and mortality associated with C. difficile infections. Biodegradable nanoparticles composed of poly-γ-glutamic acid (γ-PGA and chitosan have proven to be a safe and effective antigen delivery system for many viral vaccines. However, few studies have used this efficient antigen carrier for bacterial vaccine development. In this study, we eliminated the toxin activity domain of toxin B by constructing a recombinant protein rTcdB consists of residues 1852-2363 of TcdB receptor binding domain. The rTcdB was encapsulated in nanoparticles composed of γ-PGA and chitosan. Three rounds of intraperitoneal vaccination led to high anti-TcdB antibody responses and afforded mice full protection mice from lethal dose of C. difficile spore challenge. Protection was associated with high levels of toxin-neutralizing antibodies, and the rTcdB-encapsulated NPs elicited a longer-lasting antibody titers than antigen with the conventional adjuvant, aluminum hydroxide. Significant reductions in the level of proinflammatory cytokines and chemokines were observed in vaccinated mouse. These results suggested that polymeric nanocomplex-based vaccine design can be useful in developing vaccine against C. difficile infections.

  11. Genetic variability to diet-induced hippocampal dysfunction in BXD recombinant inbred (RI) mouse strains.

    Science.gov (United States)

    Xue, Yueqiang; Li, JingJing; Yan, Lei; Lu, Lu; Liao, Francesca-Fang

    2015-10-01

    Evidence has emerged suggesting that diet-induced obesity can have a negative effect on cognitive function. Here, we exploited a mouse genetic reference population to look for the linkage between these two processes on a genome-wide scale. The focus of this report is to determine whether the various BXD RI strains exhibited different behavioral performance and hippocampal function under high fat dietary (HFD) condition. We quantified genetic variation in body weight gain and consequent influences on behavioral tests in a cohort of 14 BXD strains of mice (8-12 mice/strain, n = 153), for which we have matched data on gene expression and neuroanatomical changes in the hippocampus. It showed that BXD66 was the most susceptible, whereas BXD77 was the least susceptible strain to dietary influences. The performance of spatial reference memory tasks was strongly correlated with body weight gain (P < 0.05). The obesity-prone strains displayed more pronounced spatial memory defects compared to the obesity-resistant strains. These abnormalities were associated with neuroinflammation, synaptic dysfunction, and neuronal loss in the hippocampus. The biological relevance of DSCAM gene polymorphism was assessed using the trait correlation analysis tool in Genenetwork. Furthermore, a significant strain-dependent gene expression difference of DSCAM was detected in the hippocampus of obese BXD strains by real-time quantitative PCR. In conclusion, a variety of across-strain hippocampal alterations and genetic predispositions to diet-induced obesity were found in a set of BXD strains. The obesity-prone and obesity-resistant lines we have identified should be highly useful to study the molecular genetics of diet-induced cognitive decline. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Epitope Mapping of Human HER2 Specific Mouse Monoclonal Antibodies Using Recombinant Extracellular Subdomains

    Science.gov (United States)

    Hosseini Ghatar, Reza; Soltantoyeh, Tahereh; Bahadori, Tannaz; Golara, Maryam; Hassannia, Hadi; Khosravi Eghbal, Roya; Khoshnoodi, Jalal; Judaki, Mohammad Ali; Golsaz-Shirazi, Forough; Jeddi-Tehrani, Mahmood; Amiri, Mohammad Mehdi; Shokri, Fazel

    2017-11-26

    Background: Human epidermal growth factor receptor 2 (HER2) is overexpressed in several human malignancies and numerous studies have indicated that it plays important roles in the development and maintenance of the malignant phenotype. Targeting of HER2 molecules with monoclonal antibodies (mAbs) is a promising therapeutic approach. However, anti-HER2 mAbs affect cancer cells differently, depending on the distinct epitopes which are the targets. Methods: Reactivity of a panel of 8 mouse anti-HER2 mAbs was investigated by ELISA and Western blotting using different subdomains of the extracellular domain (ECD) of HER2. All subdomains, including I, II, III, IV, I+II, III+IV and full HER2-ECD were constructed and expressed in CHO cells. Cross-reactivity of the mAbs with other members of the human HER family and Cynomolgus HER2 was also studied by ELISA. The mAbs were also tested by immunohistochemistry (IHC) using HER2 positive breast cancer tissues. Results: Our results demonstrated that 3 out of 8 mAbs detected conformational epitopes (1T0, 2A8 and 1B5), while 5 mAbs identified linear epitopes (1F2, 1H9, 4C7, 1H6 and 2A9). Three of the mAbs recognized subdomain I, one reacted with subdomain I+II, 2 recognized either subdomain III or IV and 2 recognized subdomain III+IV. However, none of our mAbs recognized the subdomain II alone. The mAbs displayed either inhibitory or stimulatory effects on HER2-overexpressing tumor cells and did not react with other members of the human HER family. The pattern of IHC results implied better reactivity of the mAbs recognizing linear epitopes. Conclusions: Our findings suggest that paired subdomains of HER2 are essential for mapping of mAbs recognizing conformational epitopes. Moreover, there seems to be no association between subdomain specificity and antitumor activity of our anti-HER2 mAbs. 10.22034/APJCP.2017.18.11.3103

  13. [Construction of a GFP-fused mouse PACRG baculovirus recombinant vector and expression of the fusion protein in Sf9 inset cells].

    Science.gov (United States)

    Liu, Jun-Pin; Li, Hong-Tao; Li, Wei; Liu, Hong; Zhang, Ling; Min, Jie; Zhou, Ting; Zhou, Lei; Zhang, Zhi-Bing

    2016-07-01

    To construct a GFP-fused mouse Parkin co-regulated gene (PACRG) baculovirus recombinant PACRG/GFP-pFastBac1 vector and express the fusion protein in Sf9 insect cells. Full-length mouse PACRG cDNA was amplified by PCR and cloned in frame to the vector pFastBac1 with eGFP (rpFBac-PACRG-GFP recombinant vector). The plasmid was transformed into DH10Bac cells to obtain the recombinant bacmid plasmid, the bacmid was transfected into Sf9 insect cells, and the expressed PACRG/GFP fusion protein was analyzed by Western blot and fluorescence microscopy. The construction of the PACRG/GFP-pFastBac1 baculovirus plasmid was confirmed by sequencing and restriction enzyme digestion. Western blot showed the expression of the fusion protein carrying a green fluorescence in the Sf9 insect cells. Conclusion: A PACRG/GFP-pFastBac1 recombinant baculovirus vector was successfully constructed and the fusion protein was highly expressed in the Sf9 insect cells. Our findings have provided a basis for further studies on the structure of the PACRG protein and regulation of spermatogenesis.

  14. Effectiveness of Intracavernous Delivery of Recombinant Human Hepatocyte Growth Factor on Erectile Function in the Streptozotocin-Induced Diabetic Mouse.

    Science.gov (United States)

    Das, Nando Dulal; Yin, Guo Nan; Choi, Min Ji; Song, Kang-Moon; Park, Jin-Mi; Limanjaya, Anita; Ghatak, Kalyan; Minh, Nguyen Nhat; Ock, Jiyeon; Park, Soo-Hwan; Kim, Ho Min; Ryu, Ji-Kan; Suh, Jun-Kyu

    2016-11-01

    Diabetic erectile dysfunction is a disease mostly of vascular origin and men with diabetic erectile dysfunction respond poorly to oral phosphodiesterase-5 inhibitors. Hepatocyte growth factor (HGF) is a pleiotropic factor that plays an essential role in the regulation of cell proliferation, survival, and angiogenesis. To determine the effectiveness of recombinant human (rh)-HGF in restoring erectile function in diabetic mice. Four groups of mice were used: control non-diabetic mice and streptozotocin-induced diabetic mice receiving two successive intracavernous injections of phosphate buffered saline (days -3 and 0), a single intracavernous injection of rh-HGF (day 0), or two successive intracavernous injections of rh-HGF (days -3 and 0). We also examined the effect of rh-HGF in primary cultured mouse cavernous endothelial cells and in major pelvic ganglion culture in vitro, which was incubated under a normal-glucose (5 mmol/L) or a high-glucose (30 mmol/L) condition. Two weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve and the penis was harvested for histologic studies. Repeated intracavernous injections of rh-HGF protein induced significant restoration of erectile function in diabetic mice (89-100% of control values), whereas a single intracavernous injection of rh-HGF protein elicited modest improvement. Rh-HGF significantly induced phosphorylation of its receptor c-Met, increased the content of endothelial cells and smooth muscle cells, and decreased the generation of reactive oxygen species (superoxide anion and peroxynitrite) and extravasation of oxidized low-density lipoprotein in diabetic mice. Under the high-glucose condition, rh-HGF protein also promoted tube formation in mouse cavernous endothelial cells and enhanced neurite sprouting in major pelvic ganglion culture in vitro. The dual angiogenic and neurotrophic effects of HGF could open a new avenue through which diabetic erectile dysfunction

  15. Assessment of tropism and effectiveness of new primate-derived hybrid recombinant AAV serotypes in the mouse and primate retina

    National Research Council Canada - National Science Library

    Charbel Issa, Peter; De Silva, Samantha R; Lipinski, Daniel M; Singh, Mandeep S; Mouravlev, Alexandre; You, Qisheng; Barnard, Alun R; Hankins, Mark W; During, Matthew J; Maclaren, Robert E

    2013-01-01

    ...(-/-) mouse which is a model for Stargardt disease and in the Pde6b(rd1/rd1) mouse) in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette...

  16. Environmentally Relevant Chronic Low-Dose Tritium and Gamma Exposures do not Increase Somatic Intrachromosomal Recombination in pKZ1 Mouse Spleen.

    Science.gov (United States)

    Bannister, Laura; Serran, Mandy; Bertrand, Lindsey; Klokov, Dmitry; Wyatt, Heather; Blimkie, Melinda; Gueguen, Yann; Priest, Nicholas; Jourdain, Jean-René; Sykes, Pamela

    2016-12-01

    The toxicity of tritium is a public health concern given its presence and mobility in the environment. For risk predictions using radiological protection models, it is essential to allocate an appropriate radiation weighting factor (WR). This in turn should be consistent with the observed relative biological effectiveness (RBE) of tritium beta radiation. Although the International Commission on Radiological Protection (ICRP) currently recommends a WR of 1 for the calculation of committed effective dose for X rays, gamma rays and electrons of all energies, including tritium energies, there are concerns that tritium health risks are underestimated and that current regulatory tritium drinking water standards need revision. In this study, we investigated potential cytotoxic and genotoxic effects in mouse spleen after one month and eight months of chronic exposure to low-dose tritiated water (HTO). The dose regimes studied were designed to mimic human chronic consumption of HTO at levels of 10 kBq/l, 1 MBq/l and 20 MBq/l. The total doses from these radiation exposures ranged from 0.01 to 180 mGy. We also compared the biological effects of exposure to HTO with equivalent exposure to external whole-body (60)Co gamma rays. Changes in spleen weight and somatic intrachromosomal recombination (DNA inversions) in spleen tissue of pKZ1(Tg/+) mice were monitored. Our results showed no overall changes in either spleen organ weights and no increase mouse splenic intrachromosomal recombination frequencies, indicating that current drinking water standards for tritium exposure in the form of HTO are likely to be adequately protective against cytotoxic and genotoxic damage in spleen. These results demonstrate no evidence for cytotoxicity or genotoxicity in mouse spleen following chronic exposures to HTO activities (or equivalent gamma doses) up to 20 MBq/L.

  17. Towards mouse models of perseveration: a heritable component in extinction of operant behavior in fourteen standard and recombinant inbred mouse lines.

    NARCIS (Netherlands)

    Malkki, H.A.I.; Donga, L.A.B.; de Groot, S.E.; Brussaard, A.B.; Borst, J.G.G.; Elgersma, J.W.; Galjart, N.; van der Horst, G.T.; Levelt, C.N.; Pennartz, C.M.A.; Smit, A.B.; Spruijt, B.M.; Verhage, M.; de Zeeuw, C.I.; Battaglia, F.P.

    2011-01-01

    Extinction of instrumental responses is an essential skill for adaptive behavior such as foraging. So far, only few studies have focused on extinction following appetitive conditioning in mice. We studied extinction of appetitive operant lever-press behavior in six standard inbred mouse strains

  18. Noninvasive Imaging Reveals Stable Transgene Expression in Mouse Airways After Delivery of a Nonintegrating Recombinant Adeno-Associated Viral Vector

    NARCIS (Netherlands)

    Vidovic, D; Gijsbers, R; Quiles Jimenez, A; Dooley, J; Van Den Haute, C; Van der Perren, A; Liston, A; Baekelandt, V; Debyser, Z; Carlon, MS

    2015-01-01

    Gene therapy holds promise to cure a wide range of genetic and acquired diseases. Recent successes in recombinant adeno-associated viral vector (rAAV)-based gene therapy in the clinic for hereditary disorders such as Leber's congenital amaurosis and hemophilia B encouraged us to reexplore an rAAV

  19. Mouse TRIP13/PCH2 Is Required for Recombination and Normal Higher-Order Chromosome Structure during Meiosis

    NARCIS (Netherlands)

    Roig, Ignasi; Dowdle, James A.; Toth, Attila; de Rooij, Dirk G.; Jasin, Maria; Keeney, Scott

    2010-01-01

    Accurate chromosome segregation during meiosis requires that homologous chromosomes pair and become physically connected so that they can orient properly on the meiosis I spindle. These connections are formed by homologous recombination closely integrated with the development of meiosis-specific,

  20. Genetic probing of homologous recombination and non-homologous end joining during meiotic prophase in irradiated mouse spermatocytes.

    NARCIS (Netherlands)

    Ahmed, E.A.; Philippens, M.E.P.; Kal, H.B.; Rooij, D.G. de; Boer, P. de

    2010-01-01

    This study was designed to obtain a better insight into the relative contribution of homologous recombination (HR) and non-homologous end joining (NHEJ) to the repair of radiation-induced DNA double-strand breaks (DSBs) at first meiotic prophase. Early and late pachytene and early diplotene

  1. Construction of a recombinant adenovirus co-expressing truncated human prostate-specific membrane antigen and mouse 4-1BBL genes and its effect on dendritic cells.

    Science.gov (United States)

    Weng, Xiaodong; Kuang, Youlin; Liu, Xiuheng; Chen, Zhiyuan; Zhu, Hengcheng; Chen, Hui; Jiang, Botao; Shen, Hao

    2011-03-01

    Our aim was to construct a recombinant adenovirus co-expressing truncated human prostate-specific membrane antigen (tPSMA) and mouse 4-1BBL genes and to determine its effect on dendritic cells (DCs) generated from bone marrow suspensions harvested from C57BL/6 mice for which the effect of 4-1BBL on DCs is not clear, especially during DCs processing tumor-associated antigen. Replication deficient adenovirus AdMax™ Expression System was used to construct recombinant adenovirus Ad-tPSMA-internal ribosome entry site-mouse 4-1BBL (Ad-tPSMA-IRES-m4-1BBL) and Ad-enhanced green fluorescent protein. Day 7 proliferating DC aggregates generated from C57BL/6 mice were collected as immature DCs and further mature DCs were obtained by lipopolysaccharide activated immature DCs. After DCs were exposed to the recombinant adenovirus with 250 multiplicity of infection, the expression of tPSMA and m4-1BBL proteins were detected by Western blot, and the apoptosis and phenotype of DCs were analyzed by flow cytometry. Cytokines (IL-6 and IL-12) in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Proliferation of T cells was detected by allogeneic mixed lymphocyte reactions. The tPSMA and m4-1BBL proteins were expressed correctly. The apoptosis rate of DCs transfected with Ad-tPSMA-IRES-m4-1BBL was 14.6%, lower than that of control DCs. The expression of co-stimulatory molecules [CD80 (81.6 ± 5.4%) and CD86 (80.13 ± 2.81%)] up-regulated in Ad-tPSMA-IRES-m4-1BBL-pulsed DCs, and the level of IL-6 (3960.2 ± 50.54 pg/mL) and IL-12 (249.57 ± 12.51 pg/mL) production in Ad-tPSMA-IRES-m4-1BBL-transduced DCs were significantly higher (P m4-1BBL induced higher T-cell proliferation (OD(450) = 0.614 ± 0.018), indicating that this recombinant adenovirus can effectively enhance the activity of DCs.

  2. Construction of a recombinant adenovirus co-expressing truncated human prostate-specific membrane antigen and mouse 4-1BBL genes and its effect on dendritic cells

    Directory of Open Access Journals (Sweden)

    Xiaodong Weng

    2011-03-01

    Full Text Available Our aim was to construct a recombinant adenovirus co-expressing truncated human prostate-specific membrane antigen (tPSMA and mouse 4-1BBL genes and to determine its effect on dendritic cells (DCs generated from bone marrow suspensions harvested from C57BL/6 mice for which the effect of 4-1BBL on DCs is not clear, especially during DCs processing tumor-associated antigen. Replication deficient adenovirus AdMaxTM Expression System was used to construct recombinant adenovirus Ad-tPSMA-internal ribosome entry site-mouse 4-1BBL (Ad-tPSMA-IRES-m4-1BBL and Ad-enhanced green fluorescent protein. Day 7 proliferating DC aggregates generated from C57BL/6 mice were collected as immature DCs and further mature DCs were obtained by lipopolysaccharide activated immature DCs. After DCs were exposed to the recombinant adenovirus with 250 multiplicity of infection, the expression of tPSMA and m4-1BBL proteins were detected by Western blot, and the apoptosis and phenotype of DCs were analyzed by flow cytometry. Cytokines (IL-6 and IL-12 in the supernatant were detected by enzyme-linked immunosorbent assay (ELISA. Proliferation of T cells was detected by allogeneic mixed lymphocyte reactions. The tPSMA and m4-1BBL proteins were expressed correctly. The apoptosis rate of DCs transfected with Ad-tPSMA-IRES-m4-1BBL was 14.6%, lower than that of control DCs. The expression of co-stimulatory molecules [CD80 (81.6 ± 5.4% and CD86 (80.13 ± 2.81%] up-regulated in Ad-tPSMA-IRES-m4-1BBL-pulsed DCs, and the level of IL-6 (3960.2 ± 50.54 pg/mL and IL-12 (249.57 ± 12.51 pg/mL production in Ad-tPSMA-IRES-m4-1BBL-transduced DCs were significantly higher (P < 0.05 than those in control DCs. Ad-tPSMA-IRES-m4-1BBL induced higher T-cell proliferation (OD450 = 0.614 ± 0.018, indicating that this recombinant adenovirus can effectively enhance the activity of DCs.

  3. TCreERT2, a transgenic mouse line for temporal control of Cre-mediated recombination in lineages emerging from the primitive streak or tail bud.

    Science.gov (United States)

    Anderson, Matthew J; Naiche, L A; Wilson, Catherine P; Elder, Cindy; Swing, Deborah A; Lewandoski, Mark

    2013-01-01

    The study of axis extension and somitogenesis has been greatly advanced through the use of genetic tools such as the TCre mouse line. In this line, Cre is controlled by a fragment of the T (Brachyury) promoter that is active in progenitor cells that reside within the primitive streak and tail bud and which give rise to lineages emerging from these tissues as the embryonic axis extends. However, because TCre-mediated recombination occurs early in development, gene inactivation can result in an axis truncation that precludes the study of gene function in later or more posterior tissues. To address this limitation, we have generated an inducible TCre transgenic mouse line, called TCreERT2, that provides temporal control, through tamoxifen administration, in all cells emerging from the primitive streak or tail bud throughout development. TCreERT2 activity is mostly silent in the absence of tamoxifen and, in its presence, results in near complete recombination of emerging mesoderm from E7.5 through E13.5. We demonstrate the utility of the TCreERT2 line for determining rate of posterior axis extension and somite formation, thus providing the first in vivo tool for such measurements. To test the usefulness of TCreERT2 for genetic manipulation, we demonstrate that an early deletion of ß-Catenin via TCreERT2 induction phenocopies the TCre-mediated deletion of ß-Catenin defect, whereas a later induction bypasses this early phenotype and produces a similar defect in more caudal tissues. TCreERT2 provides a useful and novel tool for the control of gene expression of emerging embryonic lineages throughout development.

  4. Salvage of focal cerebral ischemic damage by transfusion of high O2-affinity recombinant hemoglobin polymers in mouse

    OpenAIRE

    Nemoto, Masaaki; Mito, Toshiaki; Brinigar, William S; Fronticelli, Clara; Koehler, Raymond C.

    2006-01-01

    Cell-free hemoglobin solutions with high oxygen affinity might be beneficial for selectively delivering oxygen to ischemic tissue. A recombinant hybrid hemoglobin molecule was designed using the human α-subunit and the bovine β-subunit, with placement of surface cysteines to permit disulfide bond polymerization of the tetramers. The resulting protein generated from an Escherichia coli expression system had a molecular mass >1 MDa, a P50 of ~3 Torr, and a cooperativity of n = 1.0. Anesthetized...

  5. Recombinant Human Hepatitis B Vaccine Initiating Alopecia Areata: Testing the Hypothesis Using the C3H/HeJ Mouse Model

    Science.gov (United States)

    Sundberg, John P.; Silva, Kathleen A.; Zhang, Weidong; Sundberg, Beth A.; Edwards, Kathryn; King, Lloyd E.; Davis, Robert L.; Black, Steven

    2010-01-01

    Untoward effects of human vaccines suggest that recombinant hepatitis B vaccine may induce alopecia areata (AA) in some patients. Similar untoward immunological effects may also account for AA-like diseases in domestic species. In this study the C3H/HeJ spontaneous adult onset AA mouse model was used to test the role, if any, of recombinant hepatitis B vaccine on the initiation or activation of AA. Initial experiments demonstrated no effect on induction of AA in young adult female C3H/HeJ mice (p =0.5689). By contrast, older females, those at the age when AA first begins to appear in this strain, had a significant increase (p = 0.0264) in the time of onset of AA suggesting that the vaccine may initiate disease in mice predisposed to AA. However, larger vaccine trials, which included diphtheria and tetanus toxoids as additional controls, did not support these initial result findings and suggest that AA associated with vaccination may be within the normal background levels of the given population. PMID:19175564

  6. Generation of a tenascin-C-CreER2 knockin mouse line for conditional DNA recombination in renal medullary interstitial cells.

    Directory of Open Access Journals (Sweden)

    Wenjuan He

    Full Text Available Renal medullary interstitial cells (RMIC are specialized fibroblast-like cells that exert important functions in maintaining body fluid homeostasis and systemic blood pressure. Here, we generated a RMIC specific tenascin-C promoter driven inducible CreER2 knockin mouse line with an EGFP reporter. Similar as endogenous tenascin-C expression, the reporter EGFP expression in the tenascin-C-CreER2(+/- mice was observed in the inner medulla of the kidney, and co-localized with COX2 but not with AQP2 or AQP1, suggesting selective expression in RMICs. After recombination (tenascin-C-CreER2(+/-/ROSA26-lacZ(+/- mice + tamoxifen, β-gal activity was restricted to the cells in the inner medulla of the kidney, and didn't co-localize with AQP2, consistent with selective Cre recombinase activity in RMICs. Cre activity was not obvious in other major organs or without tamoxifen treatment. This inducible RMIC specific Cre mouse line should therefore provide a novel tool to manipulate genes of interest in RMICs.

  7. Chaperone–Mediated Gene Therapy with Recombinant AAV-PPCA in a New Mouse Model of Type I Sialidosis

    OpenAIRE

    Bonten, Erik J.; Yogalingam, Gouri; Hu, Huimin; Gomero, Elida; van de Vlekkert, Diantha; d’Azzo, Alessandra

    2013-01-01

    The lysosomal storage disease sialidosis is caused by a primary deficiency of the sialidase NEU1. Patients with type I sialidosis develop an attenuated, non-neuropathic form of the disease also named cherry red spot myoclonus syndrome, with symptoms arising during juvenile/ adult age. NEU1 requires binding to its chaperone, protective protein/cathepsin A (PPCA), for lysosomal compartmentalization, stability and catalytic activation. We have generated a new mouse model of type I sialidosis tha...

  8. Systemic delivery of recombinant brain derived neurotrophic factor (BDNF in the R6/2 mouse model of Huntington's disease.

    Directory of Open Access Journals (Sweden)

    Carmela Giampà

    Full Text Available Loss of huntingtin-mediated BDNF gene transcription has been shown to occur in HD and thus contribute to the degeneration of the striatum. Several studies have indicated that an increase in BDNF levels is associated with neuroprotection and amelioration of neurological signs in animal models of HD. In a recent study, an increase in BDNF mRNA and protein levels was recorded in mice administered recombinant BDNF peripherally. Chronic, indwelling osmotic mini-pumps containing either recombinant BDNF or saline were surgically placed in R6/2 or wild-type mice from 4 weeks of age until euthanasia. Neurological evaluation (paw clasping, rotarod performance, locomotor activity in an open field was performed. After transcardial perfusion, histological and immunohistochemical studies were performed. We found that BDNF- treated R6/2 mice survived longer and displayed less severe signs of neurological dysfunction than the vehicle treated ones. Primary outcome measures such as brain volume, striatal atrophy, size and morphology of striatal neurons, neuronal intranuclear inclusions and microglial reaction confirmed a neuroprotective effect of the compound. BDNF was effective in increasing significantly the levels of activated CREB and of BDNF the striatal spiny neurons. Moreover, systemically administered BDNF increased the synthesis of BDNF as demonstrated by RT-PCR, and this might account for the beneficial effects observed in this model.

  9. Rabies-virus-glycoprotein-pseudotyped recombinant baculovirus vaccine confers complete protection against lethal rabies virus challenge in a mouse model.

    Science.gov (United States)

    Wu, Qunfeng; Yu, Fulai; Xu, Jinfang; Li, Yang; Chen, Huanchun; Xiao, Shaobo; Fu, Zhen F; Fang, Liurong

    2014-06-25

    Rabies virus has been an ongoing threat to humans and animals. Here, we developed a new strategy to generate a rabies virus vaccine based on a pseudotyped baculovirus. The recombinant baculovirus (BV-RVG/RVG) was pseudotyped with the rabies virus glycoprotein (RVG) and also simultaneously expressed another RVG under the control of the immediate early CMV promoter. In vitro, this RVG-pseudotyped baculovirus vector induced syncytium formation in insect cells and displayed more efficient gene delivery into mammalian cells. Mice immunized with BV-RVG/RVG developed higher levels of virus-neutralizing antibodies, and conferred 100% protection against rabies viral challenge. These data indicate that the RVG-pseudotyped baculovirus BV-RVG/RVG can be used as an alternative strategy to develop a safe and efficacious vaccine against the rabies virus. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Genetic probing of homologous recombination and non-homologous end joining during meiotic prophase in irradiated mouse spermatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Emad A. [Department of Endocrinology and Metabolism, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands); Department of Zoology, Faculty of Science, Assiut University, 71516 Assiut (Egypt); Philippens, Marielle E.P.; Kal, Henk B. [Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Rooij, Dirk G. de, E-mail: d.g.derooij@uu.nl [Department of Endocrinology and Metabolism, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands); Center for Reproductive Medicine, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam (Netherlands); Boer, Peter de [Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen (Netherlands)

    2010-06-01

    This study was designed to obtain a better insight into the relative contribution of homologous recombination (HR) and non-homologous end joining (NHEJ) to the repair of radiation-induced DNA double-strand breaks (DSBs) at first meiotic prophase. Early and late pachytene and early diplotene spermatocytes that had completed crossing over were sampled. We studied the kinetics of {gamma}-H2AX chromatin foci removal after irradiation of mice deficient for HR and mice deficient for NHEJ. Analyzing {gamma}-H2AX signals in unirradiated RAD54/RAD54B deficient spermatocytes indicated incomplete meiotic recombination repair due to the pronounced increase of {gamma}-H2AX foci in late prophase primary spermatocytes. In these mice, 8 h after irradiation, early pachytene spermatocytes showed a reduction of the numbers of {gamma}-H2AX foci by 52% compared to 82% in the wild type, the difference being significant. However, after crossing over (in late pachytene and early diplotene), no effect of RAD54/RAD54B deficiency on the reduction of irradiation-induced foci was observed. In NHEJ deficient SCID mice, repair kinetics in early spermatocytes were similar to those in wild type mice. However, 1 h after irradiation in late pachytene and early diplotene spermatocytes 1.7 times more foci were found than in wild type mice. This difference might be related to the absence of a DNA-PKcs dependent fast repair component in SCID mice. As subsequent repair is normal, HR likely is taking over. Taken together, the results obtained in RAD54/RAD54B deficient mice and in SCID mice indicate that DSB repair in early pachytene spermatocytes is mainly carried out through HR. In late spermatocytes (late pachytenes and early diplotenes) NHEJ is active. However, probably there is an interplay between these repair pathways and when in late spermatocytes the NHEJ pathway is compromised HR may take over.

  11. Eukaryotic expression, purification and structure/function analysis of native, recombinant CRISP3 from human and mouse

    Science.gov (United States)

    Volpert, Marianna; Mangum, Jonathan E.; Jamsai, Duangporn; D'Sylva, Rebecca; O'Bryan, Moira K.; McIntyre, Peter

    2014-02-01

    While the Cysteine-Rich Secretory Proteins (CRISPs) have been broadly proposed as regulators of reproduction and immunity, physiological roles have yet to be established for individual members of this family. Past efforts to investigate their functions have been limited by the difficulty of purifying correctly folded CRISPs from bacterial expression systems, which yield low quantities of correctly folded protein containing the eight disulfide bonds that define the CRISP family. Here we report the expression and purification of native, glycosylated CRISP3 from human and mouse, expressed in HEK 293 cells and isolated using ion exchange and size exclusion chromatography. Functional authenticity was verified by substrate-affinity, native glycosylation characteristics and quaternary structure (monomer in solution). Validated protein was used in comparative structure/function studies to characterise sites and patterns of N-glycosylation in CRISP3, revealing interesting inter-species differences.

  12. Combination of targeting gene-viro therapy with recombinant Fowl-pox viruses with HN and VP3 genes on mouse osteosarcoma.

    Science.gov (United States)

    Zhang, Z-Y; Wang, L-Q; Fu, C-F; Li, X; Cui, Z-L; Zhang, J-Y; Xue, S-H; Sun, N; Xu, F

    2013-03-01

    Osteosarcoma is an aggressive cancerous neoplasm arising from primitive transformed cells of mesenchymal origin that exhibit osteoblastic differentiation and produce malignant osteoid. With the rapid development of tumor molecular biology, gene and viral therapy, a highly promising strategy for the treatment, has shown some therapeutic effects. To study the strategy of cooperative cancer gene therapy, previously, we explored the antitumor effects of recombinant Fowl-pox viruses (FPVs) with both HN (hemagglutinin-neuramidinase) and VP3 genes on mouse osteosarcoma. We constructed vFV-HN, vFV-VP3 and vFV-HN-VP3 inserting CAV VP3 gene, NDV HN gene into fowlpox virus. S180 osteosarcoma were transfected with Recombinant Fowl-pox viruses (FPVs). These cell lines stably expressing tagged proteins were selected by culturing in medium containing puromycin (2 µg/ml) and confirmed by immunoblotting and immunostaining. S180 osteosarcoma model with BALB/c mice and nude mice were established and the vFPV viruses as control, vFV-HN, vFV-VP3, vFV-HN-VP3 were injected into the tumor directly. The rate of tumor growth, tumor suppression and the sialic acid levels in serum were examined and the tumor tissues were analyzed by the method of immunohistochemistry. Flow cytometric analysis was performed using a FACSCalibur flow cytometer. A total of 100,000 events were analyzed for each sample and the experiment was repeated at least twice. Our data indicated that vFV-HN, vFV-VP3 and vFV-HN-VP3 all had growth inhibition effects, the inhibition rate of vFV-HN-VP3 group was 51.7%, which was higher than that of vFV-HN, vFV-VP3 group and control group (p genes into mouse osteosarcoma cancer cells can cause cell a specificity anti-tumor immune activity, suppress tumor growth, and increase the survival rate of the tumor within host.

  13. Effect of Acute Swim Stress on Plasma Corticosterone and Brain Monoamine Levels in Bidirectionally Selected DxH Recombinant Inbred Mouse Strains Differing in Fear Recall and Extinction

    Science.gov (United States)

    Browne, Caroline A.; Hanke, Joachim; Rose, Claudia; Walsh, Irene; Foley, Tara; Clarke, Gerard; Schwegler, Herbert; Cryan, John F.; Yilmazer-Hanke, Deniz

    2015-01-01

    Stress-induced changes in plasma corticosterone and central monoamine levels were examined in mouse strains that differ in fear-related behaviors. Two DxH recombinant inbred mouse strains with a DBA/2J background, which were originally bred for a high (H-FSS) and low fear-sensitized acoustic startle reflex (L-FSS), were used. Levels of noradrenaline, dopamine, and serotonin and their metabolites (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were studied in the amygdala, hippocampus, medial prefrontal cortex, striatum, hypothalamus, and brainstem. H-FSS mice exhibited increased fear levels and a deficit in fear extinction (within-session) in the auditory fear-conditioning test, and depressive-like behavior in the acute forced swim stress test. They had higher tissue noradrenaline and serotonin levels and lower dopamine and serotonin turnover under basal conditions, although they were largely insensitive to stress-induced changes in neurotransmitter metabolism. In contrast, acute swim stress increased monoamine levels but decreased turnover in the less fearful L-FSS mice. L-FSS mice also showed a trend toward higher basal and stress-induced corticosterone levels and an increase in noradrenaline and serotonin in the hypothalamus and brainstem 30 minutes after stress compared to H-FSS mice. Moreover, the dopaminergic system was activated differentially in the medial prefrontal cortex and striatum of the two strains by acute stress. Thus, H-FSS mice showed increased basal noradrenaline tissue levels compatible with a fear phenotype or chronic stressed condition. Low corticosterone levels and the poor monoamine response to stress in H-FSS mice may point to mechanisms similar to those found in principal fear disorders or posttraumatic stress disorder. PMID:25117886

  14. Salvage of focal cerebral ischemic damage by transfusion of high O2-affinity recombinant hemoglobin polymers in mouse.

    Science.gov (United States)

    Nemoto, Masaaki; Mito, Toshiaki; Brinigar, William S; Fronticelli, Clara; Koehler, Raymond C

    2006-05-01

    Cell-free hemoglobin solutions with high oxygen affinity might be beneficial for selectively delivering oxygen to ischemic tissue. A recombinant hybrid hemoglobin molecule was designed using the human alpha-subunit and the bovine beta-subunit, with placement of surface cysteines to permit disulfide bond polymerization of the tetramers. The resulting protein generated from an Escherichia coli expression system had a molecular mass >1 MDa, a P50 of approximately 3 Torr, and a cooperativity of n = 1.0. Anesthetized mice were transfused during 2-h occlusion of the middle cerebral artery. Compared with transfusion with 5% albumin, cerebral infarct volume was reduced by 41% with transfusion of a 3% solution of the high oxygen-affinity hemoglobin polymer and by 50% with transfusion of a 6% solution of the polymer. Transfusion of a 6% solution of a 500-kDa polymer possessing a P50 of 17 Torr and a cooperativity of n = 2.0 resulted in a 66% reduction of infarct volume. These results indicate that cell-free Hb polymers with P50 values much lower than that of red blood cell hemoglobin are highly capable of salvaging ischemic brain. The assumption that the P50 of blood substitutes should be similar to that of blood might not be warranted when used during ischemic conditions.

  15. Recombinant human activated protein C improves endotoxemia-induced endothelial dysfunction: a blood-free model in isolated mouse arteries.

    Science.gov (United States)

    Sennoun, Nacira; Baron-Menguy, Celine; Burban, Mélanie; Lecompte, Thomas; Andriantsitohaina, Ramaroson; Henrion, Daniel; Mercat, Alain; Asfar, Pierre; Levy, Bruno; Meziani, Ferhat

    2009-07-01

    Recombinant human activated protein C (rhAPC) is one of the treatment panels for improving vascular dysfunction in septic patients. In a previous study, we reported that rhAPC treatment in rat endotoxemia improved vascular reactivity, although the mechanisms involved are still under debate. In the present study, we hypothesized that rhAPC may improve arterial dysfunction through its nonanticoagulant properties. Ten hours after injection of LPS in mice (50 mg/kg ip), aortic rings and mesenteric arteries were isolated and incubated with or without rhAPC for 12 h. Aortic rings were mounted in a myograph, after which arterial contractility and endothelium-dependent relaxation were measured in the presence or absence of nitric oxide synthase or cyclooxygenase inhibitors. Flow (shear stress)-mediated dilation with or without the above inhibitors was also measured in mesenteric resistance arteries. Protein expression was assessed by Western blotting. Lipopolysaccharide (LPS) reduced aortic contractility to KCl and phenylephrine as well as dilation to acetylcholine. LPS also reduced flow-mediated dilation in mesenteric arteries. In rhAPC-treated aorta and mesenteric arteries, contractility and endothelial responsiveness to vasodilator drug and shear stress were improved. rhAPC treatment also improved LPS-induced endothelial dysfunction; this effect was associated with an increase in the phosphorylated form of endothelial nitric oxide synthase and protein kinase B as well as cyclooxygenase vasodilatory pathways, thus suggesting that these pathways, together with the decrease in nuclear factor-kappaB activation and inducible nitric oxide synthase expression in the vascular wall, are implicated in the endothelial effect of rhAPC. In conclusion, ex vivo application of rhAPC improves arterial contractility and endothelial dysfunction resulting from endotoxemia in mice. This finding provides important insights into the mechanism underlying rhAPC-induced improvements on arterial

  16. Recombinant mouse prion protein alone or in combination with lipopolysaccharide alters expression of innate immunity genes in the colon of mice.

    Science.gov (United States)

    Dervishi, Elda; Lam, Tran H; Dunn, Suzana M; Zwierzchowski, Grzegorz; Saleem, Fozia; Wishart, David S; Ametaj, Burim N

    2015-01-01

    The objectives of this study were to test whether recombinant mouse (mo)PrP alone or in combination with LPS or under simulated endotoxemia would affect expression of genes related to host inflammatory and antimicrobial responses. To test our hypotheses colon tissues were collected from 16 male mice (FVB/N strain) and mounted in an Ussing chamber. Application of moPrP to the mucosal side of the colon affected genes related to TLR- and NLR- signaling and antimicrobial responses. When LPS was added on the mucosal side of the colon, genes related to TLR, Nlrp3 inflammasome, and iron transport proteins were over-expressed. Addition of LPS to the serosal side of the colon up-regulated genes related to TLR- and NLR-signaling, Nlrp3 inflammasome, and a chemokine. Treatment with both moPrP and LPS to the mucosal side of the colon upregulated genes associated with TLR, downstream signal transduction (DST), inflammatory response, attraction of dendritic cells to the site of inflammation, and the JNK-apoptosis pathway. Administration of moPrP to the mucosal side and LPS to the serosal side of the colon affected genes related to TLR- and NLR-signaling, DST, apoptosis, inflammatory response, cytokines, chemokines, and antimicrobial peptides. Overall this study suggests a potential role for moPrP as an endogenous 'danger signal' associated with activation of colon genes related to innate immunity and antibacterial responses.

  17. Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

    Directory of Open Access Journals (Sweden)

    Xuzhu Lin

    2017-11-01

    Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

  18. Using gene expression databases for classical trait QTL candidate gene discovery in the BXD recombinant inbred genetic reference population: Mouse forebrain weight

    Directory of Open Access Journals (Sweden)

    Zhou Jianhua

    2008-09-01

    Full Text Available Abstract Background Successful strategies for QTL gene identification benefit from combined experimental and bioinformatic approaches. Unique design aspects of the BXD recombinant inbred line mapping panel allow use of archived gene microarray expression data to filter likely from unlikely candidates. This prompted us to propose a simple five-filter protocol for candidate nomination. To filter more likely from less likely candidates, we required candidate genes near to the QTL to have mRNA abundance that correlated with the phenotype among the BXD lines as well as differed between the parental lines C57BL/6J and DBA/2J. We also required verification of mRNA abundance by an independent method, and finally we required either differences in protein levels or confirmed DNA sequence differences. Results QTL mapping of mouse forebrain weight in 34 BXD RI lines found significant association on chromosomes 1 and 11, with each C57BL/6J allele increasing weight by more than half a standard deviation. The intersection of gene lists that were within ± 10 Mb of the strongest associated location, that had forebrain mRNA abundance correlated with forebrain weight among the BXD, and that had forebrain mRNA abundance differing between C57BL/6J and DBA/2J, produced two candidates, Tnni1 (troponin 1 and Asb3 (ankyrin repeat and SOCS box-containing protein 3. Quantitative RT-PCR confirmed the direction of an increased expression in C57BL/6J genotype over the DBA/2J genotype for both genes, a difference that translated to a 2-fold difference in Asb3 protein. Although Tnni1 protein differences could not be confirmed, a 273 bp indel polymorphism was discovered 1 Kb upstream of the transcription start site. Conclusion Delivery of well supported candidate genes following a single quantitative trait locus mapping experiment is difficult. However, by combining available gene expression data with QTL mapping, we illustrated a five-filter protocol that nominated Asb3 and

  19. Immunization with a recombinant vaccinia virus that encodes nonstructural proteins of the hepatitis C virus suppresses viral protein levels in mouse liver.

    Directory of Open Access Journals (Sweden)

    Satoshi Sekiguchi

    Full Text Available Chronic hepatitis C, which is caused by infection with the hepatitis C virus (HCV, is a global health problem. Using a mouse model of hepatitis C, we examined the therapeutic effects of a recombinant vaccinia virus (rVV that encodes an HCV protein. We generated immunocompetent mice that each expressed multiple HCV proteins via a Cre/loxP switching system and established several distinct attenuated rVV strains. The HCV core protein was expressed consistently in the liver after polyinosinic acid-polycytidylic acid injection, and these mice showed chronic hepatitis C-related pathological findings (hepatocyte abnormalities, accumulation of glycogen, steatosis, liver fibrosis, and hepatocellular carcinoma. Immunization with one rVV strain (rVV-N25, which encoded nonstructural HCV proteins, suppressed serum inflammatory cytokine levels and alleviated the symptoms of pathological chronic hepatitis C within 7 days after injection. Furthermore, HCV protein levels in liver tissue also decreased in a CD4 and CD8 T-cell-dependent manner. Consistent with these results, we showed that rVV-N25 immunization induced a robust CD8 T-cell immune response that was specific to the HCV nonstructural protein 2. We also demonstrated that the onset of chronic hepatitis in CN2-29((+/-/MxCre((+/- mice was mainly attributable to inflammatory cytokines, (tumor necrosis factor TNF-α and (interleukin IL-6. Thus, our generated mice model should be useful for further investigation of the immunological processes associated with persistent expression of HCV proteins because these mice had not developed immune tolerance to the HCV antigen. In addition, we propose that rVV-N25 could be developed as an effective therapeutic vaccine.

  20. THE EFFECT OF RECOMBINANT HUMAN LEUKEMIA INHIBITORY FACTOR (rhLIF ON IN VITRO DEVELOPMENT OF MOUSE 2-CELL EMBRYOS AND THEIR ISOLATED BLASTOMERES

    Directory of Open Access Journals (Sweden)

    MOHAMMAD AKBARI

    2004-09-01

    Full Text Available In this study effect of recombinant human leukemia inhibitory factor on invitro development of 2 cells embryos and isolated blastomeres derived from mouse 2 cell embryos were investigated. Female ICR mice that were between 8 to 10 weeks old received intraperitoneal injection of 7.5 IU of PMSG for super ovulation followed by intraperitoneal administration of 7.5 IU of HCG 48 hours later. The mice were then mated to mature ICR male mice and were checked for vaginal plugs after 13-14 hours. Mice were killed 46-48 hours after HCG injection by cervical dislocation, their oviducts were removed and flushing 2 cell embryos were collected. The zona pellucida of 2 cell embryos were removed by Acid Tyrod solution and blastomeres separated with oocyte preparation pipette and then all embryos and blastomeres were cultured in Potassium Simplex Optimized Medium (KSOM +Aminoacid (AA different amounts of rhLIF (500IU/ml, 1000IU/ml and 1500IU/ml. Some embryos and individual blastomere also were cultured without rhLIF as control group. All samples were cultured in an incubator at 370C with 0.05 CO2 for 120 hours. The rate of embryo and individual blastomeres which reached to 2 cell, 4 cell, 8 cell and 9-16 cell were the same in all groups. However in further developmental stages, morula and blastocyst between experimental and control groups were significantly different. Therefore it may be concluded that: cultivation of isolated blastomers up to the blastocyst stage with rhLIF has stimulatory effect on the preimplantation stage (morula and blastocyst but it has no stimulatory and inhibitory effects when was added to culture media at the early cleavage stage.

  1. Loss of Resistance to Angiotensin II-Induced Hypertension in the Jackson Laboratory Recombination-Activating Gene Null Mouse on the C57BL/6J Background.

    Science.gov (United States)

    Ji, Hong; Pai, Amrita V; West, Crystal A; Wu, Xie; Speth, Robert C; Sandberg, Kathryn

    2017-06-01

    Resistance to angiotensin II (Ang II)-induced hypertension in T-cell-deficient male mice with a targeted mutation in the recombination-activating gene-1 (Rag1) on the C57BL/6J background (B6.Rag1(-/-) -M), which was reported by 5 independent laboratories including ours before 2015, has been lost. In mice purchased from Jackson Laboratory in 2015 and 2016, the time course and magnitude increase in mean arterial pressure induced by 2 weeks of Ang II infusion at 490 ng/kg per minute was identical between B6.Rag1(-/-) -M and male wild-type littermates. Moreover, there were no differences in the time course or magnitude increase in mean arterial pressure at the lowest dose of Ang II (200 ng/kg per minute) that increased mean arterial pressure. This loss in Ang II resistance is independent of T cells. Angiotensin type 1-receptor binding was 1.4-fold higher in glomeruli isolated from recently purchased B6.Rag1(-/-) -M suggesting an increase in renal angiotensin type 1-receptor activity masks the blood pressure protection afforded by the lack of T cells. The phenotypic change in B6.Rag1(-/-) -M has implications for investigators using this strain to study mechanisms of T-cell modulation of Ang II-dependent blood pressure control. These findings also serve as a reminder that the universal drive for genetic variation occurs in all animals including inbred mouse strains and that spontaneous mutations leading to phenotypic change can compromise experimental reproducibility over time and place. Finally, these observations illustrate the importance of including experimental details about the location and time period over which animals are bred in publications involving animal studies to promote rigor and reproducibility in the scientific literature. © 2017 American Heart Association, Inc.

  2. A novel dualistic profile of an allosteric AMPA receptor modulator identified through studies on recombinant receptors, mouse hippocampal synapses and crystal structures.

    Science.gov (United States)

    Christiansen, G B; Harbak, B; Hede, S E; Gouliaev, A H; Olsen, L; Frydenvang, K; Egebjerg, J; Kastrup, J S; Holm, M M

    2015-12-03

    Positive allosteric modulators (PAMs) of 2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptors receive increasing interest as therapeutic drugs and have long served as important experimental tools in the study of the molecular mechanisms underlying glutamate-mediated neurotransmission. The aim of this study was to investigate functional and structural aspects of a novel analog of the AMPA receptor PAM cyclothiazide (CTZ) on recombinant and native glutamate receptors. We expressed rat GluA4flip and flop in Xenopus oocytes and characterized NS1376 and CTZ under two-electrode voltage-clamp. The dose-response analyses revealed dual effects of NS1376. The modulator induced 30-fold and 42-fold reductions in glutamate potency and increased the glutamate efficacy by 3.2-fold and 5.3-fold at GluA4flip and GluA4flop, respectively. Rapid application of glutamate to excised outside-out patches showed that NS1376 markedly attenuated desensitization, supporting the increased efficacy observed in the oocytes. Furthermore, when applied to acutely isolated mouse brain slices, NS1376 reduced the field excitatory postsynaptic potentials (fEPSPs) in the hippocampus to 51.6 ± 4.3% of baseline, likely as a consequence of reduced glutamate potency. However, the modulator displayed no effects on a sub-maximal long-term potentiation (LTP) protocol. We confirmed that CTZ increases presynaptic transmitter release, a property which was not shared by NS1376. Finally, we obtained detailed molecular information through X-ray structures, docking and molecular dynamics, which revealed that NS1376 interacts at the dimer interface of the ligand-binding domain in a manner overall similar to CTZ. NS1376 reveals that minor structural changes in CTZ can result in an altered modulatory profile, both enhancing agonist efficacy while markedly reducing agonist potency. These unique properties add new aspects to the complexity of allosteric modulations in neuronal systems. Copyright

  3. Assessment of Tropism and Effectiveness of New Primate-Derived Hybrid Recombinant AAV Serotypes in the Mouse and Primate Retina: e60361

    National Research Council Canada - National Science Library

    Peter Charbel Issa; Samantha R De Silva; Daniel M Lipinski; Mandeep S Singh; Alexandre Mouravlev; Qisheng You; Alun R Barnard; Mark W Hankins; Matthew J During; Robert E MacLaren

    2013-01-01

    ... (the Abca4-/- mouse which is a model for Stargardt disease and in the Pde6brd1/rd1 mouse) in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette...

  4. Norovirus recombination

    National Research Council Canada - National Science Library

    Bull, Rowena A; Tanaka, Mark M; White, Peter A

    2007-01-01

    ...{at}unsw.edu.au RNA recombination is a significant driving force in viral evolution. Increased awareness of recombination within the genus Norovirus of the family Calicivirus has led to a rise in the identification of norovirus (NoV...

  5. Isolation of Mal d 1 and Api g 1 - specific recombinant antibodies from mouse IgG Fab fragment libraries - Mal d 1-specific antibody exhibits cross-reactivity against Bet v 1.

    Science.gov (United States)

    Haka, Jaana; Niemi, Merja H; Iljin, Kristiina; Reddy, Vanga Siva; Takkinen, Kristiina; Laukkanen, Marja-Leena

    2015-05-27

    Around 3-5% of the population suffer from IgE-mediated food allergies in Western countries and the number of food-allergenic people is increasing. Individuals with certain pollen allergies may also suffer from a sensitisation to proteins in the food products. As an example a person sensitised to the major birch pollen allergen, Bet v 1, is often sensitised to its homologues, such as the major allergens of apple, Mal d 1, and celery, Api g 1, as well. Development of tools for the reliable, sensitive and quick detection of allergens present in various food products is essential for allergic persons to prevent the consumption of substances causing mild and even life-threatening immune responses. The use of monoclonal antibodies would ensure the specific detection of the harmful food content for a sensitised person. Mouse IgG antibody libraries were constructed from immunised mice and specific recombinant antibodies for Mal d 1 and Api g 1 were isolated from the libraries by phage display. More detailed characterisation of the resulting antibodies was carried out using ELISA, SPR experiments and immunoprecipitation assays. The allergen-specific Fab fragments exhibited high affinity towards the target recombinant allergens. Furthermore, the Fab fragments also recognised native allergens from natural sources. Interestingly, isolated Mal d 1-specific antibody bound also to Bet v 1, the main allergen eliciting the cross-reactivity syndrome between the birch pollen and apple. Despite the similarities in Api g 1 and Bet v 1 tertiary structures, the isolated Api g 1-specific antibodies showed no cross-reactivity to Bet v 1. Here, high-affinity allergen-specific recombinant antibodies were isolated with interesting binding properties. With further development, these antibodies can be utilised as tools for the specific and reliable detection of allergens from different consumable products. This study gives new preliminary insights to elucidate the mechanism behind the pollen

  6. Exploration of the genetic organization of morphological modularity on the mouse mandible using a set of interspecific recombinant congenic strains between C57BL/6 and mice of the Mus spretus species.

    Science.gov (United States)

    Burgio, Gaëtan; Baylac, Michel; Heyer, Evelyne; Montagutelli, Xavier

    2012-10-01

    Morphological integration and modularity within semi-autonomous modules are essential mechanisms for the evolution of morphological traits. However, the genetic makeup responsible for the control of variational modularity is still relatively unknown. In our study, we tested the hypothesis that the genetic variation for mandible shape clustered into two morphogenetic components: the alveolar group and the ascending ramus. We used the mouse as a model system to investigate genetics determinants of mandible shape. To do this, we used a combination of geometric morphometric tools and a set of 18 interspecific recombinant congenic strains (IRCS) derived from the distantly related species, Mus spretus SEG/Pas and Mus musculus C57BL/6. Quantitative trait loci (QTL) analysis comparing mandible morphometry between the C57BL/6 and the IRCSs identified 42 putative SEG/Pas segments responsible for the genetic variation. The magnitude of the QTL effects was dependent on the proportion of SEG/Pas genome inherited. Using a multivariate correlation coefficient adapted for modularity assessment and a two-block partial least squares analysis to explore the morphological integration, we found that these QTL clustered into two well-integrated morphogenetic groups, corresponding to the ascending ramus and the alveolar region. Together, these results provide evidence that the mouse mandible is subjected to genetic coordination in a modular manner.

  7. Effect of recombinant-LH and hCG in the absence of FSH on in vitro maturation (IVM) fertilization and early embryonic development of mouse germinal vesicle (GV)-stage oocytes.

    Science.gov (United States)

    Dinopoulou, Vasiliki; Drakakis, Peter; Kefala, Stella; Kiapekou, Erasmia; Bletsa, Ritsa; Anagnostou, Elli; Kallianidis, Konstantinos; Loutradis, Dimitrios

    2016-06-01

    During in vitro maturation (IVM), intrinsic and extrinsic factors must co-operate properly in order to ensure cytoplasmic and nuclear maturation. We examined the possible effect of LH/hCG in the process of oocyte maturation in mice with the addition of recombinant LH (r-LH) and hCG in our IVM cultures of mouse germinal vesicle (GV)-stage oocytes. Moreover, the effects of these hormones on fertilization, early embryonic development and the expression of LH/hCG receptor were examined. Nuclear maturation of GV-stage oocytes was evaluated after culture in the presence of r-LH or hCG. Fertilization rates and embryonic development were assessed after 24h. Total RNA was isolated from oocytes of different stages of maturation and from zygotes and embryos of different stages of development in order to examine the expression of LH/hCG receptor, using RT-PCR. The in vitro nuclear maturation rate of GV-stage oocytes that received hCG was significantly higher compared to the control group. Early embryonic development was increased in the hCG and LH cultures of GV oocytes when LH was further added. The LH/hCG receptor was expressed in all stages of in vitro matured mouse oocytes and in every stage of early embryonic development. Addition of hCG in IVM cultures of mouse GV oocytes increased maturation rates significantly. LH, however, was more beneficial to early embryonic development than hCG. This suggests a promising new technique in basic science research or in clinical reproductive medicine. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  8. Genetic Recombination Between Stromal and Cancer Cells Results in Highly Malignant Cells Identified by Color-Coded Imaging in a Mouse Lymphoma Model.

    Science.gov (United States)

    Nakamura, Miki; Suetsugu, Atsushi; Hasegawa, Kousuke; Matsumoto, Takuro; Aoki, Hitomi; Kunisada, Takahiro; Shimizu, Masahito; Saji, Shigetoyo; Moriwaki, Hisataka; Hoffman, Robert M

    2017-12-01

    The tumor microenvironment (TME) promotes tumor growth and metastasis. We previously established the color-coded EL4 lymphoma TME model with red fluorescent protein (RFP) expressing EL4 implanted in transgenic C57BL/6 green fluorescent protein (GFP) mice. Color-coded imaging of the lymphoma TME suggested an important role of stromal cells in lymphoma progression and metastasis. In the present study, we used color-coded imaging of RFP-lymphoma cells and GFP stromal cells to identify yellow-fluorescent genetically recombinant cells appearing only during metastasis. The EL4-RFP lymphoma cells were injected subcutaneously in C57BL/6-GFP transgenic mice and formed subcutaneous tumors 14 days after cell transplantation. The subcutaneous tumors were harvested and transplanted to the abdominal cavity of nude mice. Metastases to the liver, perigastric lymph node, ascites, bone marrow, and primary tumor were imaged. In addition to EL4-RFP cells and GFP-host cells, genetically recombinant yellow-fluorescent cells, were observed only in the ascites and bone marrow. These results indicate genetic exchange between the stromal and cancer cells. Possible mechanisms of genetic exchange are discussed as well as its ramifications for metastasis. J. Cell. Biochem. 118: 4216-4221, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Genetic Recombination

    Science.gov (United States)

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  10. A novel dualistic profile of an allosteric AMPA receptor modulator identified through studies on recombinant receptors, mouse hippocampal synapses and crystal structures

    DEFF Research Database (Denmark)

    Christiansen, G B; Harbak, Barbara; Hede, S E

    2015-01-01

    -mediated neurotransmission. The aim of this study was to investigate functional and structural aspects of a novel analog of the AMPA receptor PAM cyclothiazide (CTZ) on recombinant and native glutamate receptors. We expressed rat GluA4flip and flop in Xenopus oocytes and characterized NS1376 and CTZ under two......-electrode voltage-clamp. The dose-response analyses revealed dual effects of NS1376. The modulator induced 30-fold and 42-fold reductions in glutamate potency and increased the glutamate efficacy by 3.2-fold and 5.3-fold at GluA4flip and GluA4flop, respectively. Rapid application of glutamate to excised outside...

  11. Recombinant PorA, the major outer membrane protein of Campylobacter jejuni, provides heterologous protection in an adult mouse intestinal colonization model.

    Science.gov (United States)

    Islam, Anjum; Raghupathy, Raj; Albert, M John

    2010-11-01

    Immunity against Campylobacter jejuni, a major food-borne pathogen causing diarrhea, is largely serotype specific. The major outer membrane protein (MOMP) of C. jejuni, PorA, is a common antigen with the potential to provide broad protection. Adult BALB/c mice were orally immunized with a recombinant glutathione S-transferase (GST) fused to PorA prepared from Campylobacter jejuni C31 (O:6,7) (GST-PorA) combined with a modified heat-labile enterotoxin of Escherichia coli as an adjuvant and later orally challenged with C31 strain or three heterologous strains: 48 (O:19), 75 (O:3), and 111 (O:1,44). Protection from colonization with the challenge organism was studied by fecal screening daily for 9 days. Serum and intestinal lavage fluid antibodies against the vaccine and Sarkosyl-purified MOMP from C31 were measured by using an enzyme-linked immunosorbent assay. The vaccine produced robust antibody responses against both antigens in serum and secretion. Since strain C31 was a poor colonizer, homologous protection could not be studied. The protective efficacies of heterologous strains were 43% (for strain 48, P < 0.001), 29% (for strain 75, P < 0.005), and 42% (for strain 111, P < 0.001) for the 9-day period compared to control mice given phosphate-buffered saline. Thus, PorA provided appreciable protection against colonization with heterologous serotypes.

  12. Expression, purification, and initial characterization of different domains of recombinant mouse 2',3'-cyclic nucleotide 3'-phosphodiesterase, an enigmatic enzyme from the myelin sheath

    Directory of Open Access Journals (Sweden)

    Kursula Petri

    2010-01-01

    Full Text Available Abstract Background 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase is an enigmatic enzyme specifically expressed at high levels in the vertebrate myelin sheath, whose function and physiological substrates are unknown. The protein consists of two domains: an uncharacterized N-terminal domain with little homology to other proteins, and a C-terminal phosphodiesterase domain. Findings In order to be able to fully characterize CNPase structurally and functionally, we have set up expression systems for different domains of CNPase, using a total of 18 different expression constructs. CNPase was expressed in E. coli with a TEV-cleavable His-tag. Enzymatic activity assays indicated that the purified proteins were active and correctly folded. The folding of both the full-length protein, as well as the N- and C-terminal domains, was also studied by synchrotron CD spectroscopy. A thermal shift assay was used to optimize buffer compositions to be used during purification and storage. The assay also indicated that CNPase was most stable at a pH of 5.5, and could be significantly stabilized by high salt concentrations. Conclusions We have been able to express and purify recombinantly several different domains of CNPase, including the isolated N-terminal domain, which is folded mainly into a β-sheet structure. The expression system can be used as an efficient tool to elucidate the role of CNPase in the myelin sheath.

  13. Recombination monitor

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-02-03

    This is a brief report on LEReC recombination monitor design considerations. The recombination produced Au78+ ion rate is reviewed. Based on this two designs are discussed. One is to use the large dispersion lattice. It is shown that even with the large separation of the Au78+ beam from the Au79+ beam, the continued monitoring of the recombination is not possible. Accumulation of Au78+ ions is needed, plus collimation of the Au79+ beam. In another design, it is shown that the recombination monitor can be built based on the proposed scheme with the nominal lattice. From machine operation point of view, this design is preferable. Finally, possible studies and the alternative strategies with the basic goal of the monitor are discussed.

  14. Structures of recombinant human and mouse NAD(P)H:quinone oxidoreductases: species comparison and structural changes with substrate binding and release.

    Science.gov (United States)

    Faig, M; Bianchet, M A; Talalay, P; Chen, S; Winski, S; Ross, D; Amzel, L M

    2000-03-28

    NAD(P)H/quinone acceptor oxidoreductase (QR1, NQO1, formerly DT-diaphorase; EC ) protects animal cells from the deleterious and carcinogenic effects of quinones and other electrophiles. In this paper we report the apoenzyme structures of human (at 1.7-A resolution) and mouse (2.8 A) QR1 and the complex of the human enzyme with the substrate duroquinone (2.5 A) (2,3,5, 6-tetramethyl-p-benzoquinone). In addition to providing a description and rationale of the structural and catalytic differences among several species, these structures reveal the changes that accompany substrate or cofactor (NAD) binding and release. Tyrosine-128 and the loop spanning residues 232-236 close the binding site, partially occupying the space left vacant by the departing molecule (substrate or cofactor). These changes highlight the exquisite control of access to the catalytic site that is required by the ping-pong mechanism in which, after reducing the flavin, NAD(P)(+) leaves the catalytic site and allows substrate to bind at the vacated position. In the human QR1-duroquinone structure one ring carbon is significantly closer to the flavin N5, suggesting a direct hydride transfer to this atom.

  15. TLR2 and TLR4 signaling pathways are required for recombinant Brucella abortus BCSP31-induced cytokine production, functional upregulation of mouse macrophages, and the Th1 immune response in vivo and in vitro.

    Science.gov (United States)

    Li, Jia-Yun; Liu, Yuan; Gao, Xiao-Xue; Gao, Xiang; Cai, Hong

    2014-09-01

    Brucella abortus is a zoonotic Gram-negative pathogen that causes brucelosis in ruminants and humans. Toll-like receptors (TLRs) recognize Brucella abortus and initiate antigen-presenting cell activities that affect both innate and adaptive immunity. In this study, we focused on recombinant Brucella cell-surface protein 31 (rBCSP31) to determine its effects on mouse macrophages. Our results demonstrated that rBCSP31 induced TNF-α, IL-6 and IL-12p40 production, which depended on the activation of mitogen-activated protein kinases (MAPKs) by stimulating the rapid phosphorylation of p38 and JNK and the activation of transcription factor NF-κB in macrophages. In addition, continuous exposure (>24 h) of RAW264.7 cells to rBCSP31 significantly enhanced IFN-γ-induced expression of MHC-II and the ability to present rBCSP31 peptide to CD4(+) T cells. Furthermore, we found that rBCSP31 could interact with both TLR2 and TLR4. The rBCSP31-induced cytokine production by macrophages from TLR2(-/-) and TLR4(-/-) mice was lower than that from C57BL/6 macrophages, and the activation of NF-κB and MAPKs was attenuated in macrophages from TLR2(-/-) and TLR4(-/-) mice. In addition, CD4(+) T cells from C57BL/6 mice immunized with rBCSP31 produced higher levels of IFN-γ and IL-2 compared with CD4(+) T cells from TLR2(-/-) and TLR4(-/-) mice. Macrophages from immunized C57BL/6 mice produced higher levels of IL-12p40 than those from TLR2(-/-) and TLR4(-/-) mice. Furthermore, immunization with rBCSP31 provided better protection in C57BL/6 mice than in TLR2(-/-) and TLR4(-/-) mice after B. abortus 2308 challenge. These results indicate that rBCSP31 is a TLR2 and TLR4 agonist that induces cytokine production, upregulates macrophage function and induces the Th1 immune response.

  16. Rats and mice immunised with chimeric human/mouse proteinase 3 produce autoantibodies to mouse Pr3 and rat granulocytes

    NARCIS (Netherlands)

    van der Geld, Ymke M.; Hellmark, Thomas; Selga, Daina; Heeringa, Peter; Huitema, Minke G.; Limburg, Pieter C.; Kallenberg, Cees G. M.

    2007-01-01

    Aim: In this study, we employed chimeric human/ mouse Proteinase 3 ( PR3) proteins as tools to induce an autoantibody response to PR3 in rats and mice. Method: Rats and mice were immunised with recombinant human PR3 ( HPR3), recombinant murine PR3 ( mPR3), single chimeric human/ mouse PR3 ( HHm,

  17. Comparison of immunoglobulin E measurements on IMMULITE and ImmunoCAP in samples consisting of allergen-specific mouse-human chimeric monoclonal antibodies towards allergen extracts and four recombinant allergens

    DEFF Research Database (Denmark)

    Szecsi, Pal B; Stender, Steen

    2013-01-01

    Specific immunoglobulin E (IgE) antibody in vitro tests are performed on enzyme immunoassay systems. Poor agreement among systems has been reported and comparisons have been made exclusively with allergen extracts - not with recombinant allergens. Here we compare the ImmunoCAP and the IMMULITE...

  18. Activation of RAW264.7 mouse macrophage cells in vitro through treatment with recombinant ricin toxin-binding subunit B: involvement of protein tyrosine, NF-κB and JAK-STAT kinase signaling pathways.

    Science.gov (United States)

    Xu, Na; Yuan, Hongyan; Liu, Wensen; Li, Songyan; Liu, Yang; Wan, Jiayu; Li, Xiaoyan; Zhang, Rui; Chang, Yaping

    2013-09-01

    Ricin toxin-binding subunit B (RTB) is a galactose-binding lectin protein. In the present study, we investigated the effects of RTB on inducible nitric oxide (NO) synthase (iNOS), interleukin (IL)-6 and tumor necrosis factor (TNF)-α, as well as the signal transduction mechanisms involved in recombinant RTB-induced macrophage activation. RAW264.7 macrophages were treated with RTB. The results revealed that the mRNA and protein expression of iNOS was increased in the recombinant RTB-treated macrophages. TNF-α production was observed to peak at 20 h, whereas the production of IL-6 peaked at 24 h. In another set of cultures, the cells were co-incubated with RTB and the tyrosine kinase inhibitor, genistein, the phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, the p42/44 inhibitor, PD98059, the p38 inhibitor, SB203580, the JNK inhibitor, SP600125, the protein kinase C (PKC) inhibitor, staurosporine, the JAK2 inhibitor, tyrphostin (AG490), or the NOS inhibitor, L-NMMA. The recombinant RTB-induced production of NO, TNF-α and IL-6 was inhibited in the macrophages treated with the pharmacological inhibitors genistein, LY294002, staurosporine, AG490, SB203580 and BAY 11-7082, indicating the possible involvement of protein tyrosine kinases, PI3K, PKC, JAK2, p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB in the above processes. A phosphoprotein analysis identified tyrosine phosphorylation targets that were uniquely induced by recombinant RTB and inhibited following treatment with genistein; some of these proteins are associated with the downstream cascades of activated JAK-STAT and NF-κB receptors. Our data may help to identify the most important target molecules for the development of novel drug therapies.

  19. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  20. Mouse Models of Arteriosclerosis

    Science.gov (United States)

    Xu, Qingbo

    2004-01-01

    Animal models are designed to be preliminary tools for better understanding of the pathogenesis, improvement in diagnosis, prevention, and therapy of arteriosclerosis in humans. Attracted by the well-defined genetic systems, a number of investigators have begun to use the mouse as an experimental system for arteriosclerosis research. Hundreds of inbred lines have been established, and the genetic map is relatively well defined, and both congenic strains and recombinant strains are available to facilitate genetic experimentation. Because arteriosclerosis is a complicated disease, which includes spontaneous (native) atherosclerosis, transplant arteriosclerosis, vein graft atherosclerosis, and angioplasty-induced restenosis, several mouse models for studying all types of arteriosclerosis have recently been established. Using these mouse models, much knowledge concerning the pathogenesis of the disease and therapeutic intervention has been gained, eg, origins of endothelial and smooth muscle cells in lesions of transplant and vein graft atherosclerosis. This review will not attempt to cover all aspects of mouse models, rather focus on models of arterial injuries, vein grafts, and transplant arteriosclerosis, by which the major progress in understanding the mechanisms of the disease has been made. This article will also point out (dis)advantages of a variety of models, and how the models can be appropriately chosen for different purposes of study. PMID:15215157

  1. Tumor-targeting Salmonella typhimurium A1-R combined with recombinant methioninase and cisplatinum eradicates an osteosarcoma cisplatinum-resistant lung metastasis in a patient-derived orthotopic xenograft (PDOX) mouse model: Decoy, trap and kill chemotherapy moves toward the clinic.

    Science.gov (United States)

    Igarashi, Kentaro; Kawaguchi, Kei; Kiyuna, Tasuku; Miyake, Kentaro; Miyake, Masuyo; Li, Shukuan; Han, Qinghong; Tan, Yuying; Zhao, Ming; Li, Yunfeng; Nelson, Scott D; Dry, Sarah M; Singh, Arun S; Elliott, Irmina A; Russell, Tara A; Eckardt, Mark A; Yamamoto, Norio; Hayashi, Katsuhiro; Kimura, Hiroaki; Miwa, Shinji; Tsuchiya, Hiroyuki; Eilber, Fritz C; Hoffman, Robert M

    2018-01-29

    In the present study, a patient-derived orthotopic xenograft (PDOX) model of recurrent cisplatinum (CDDP)-resistant metastatic osteosarcoma was treated with Salmonella typhimurium A1-R (S. typhimurium A1-R), which decoys chemoresistant quiescent cells to cycle, and recombinant methioninase (rMETase), which selectively traps cancer cells in late S/G2, and chemotherapy. The PDOX models were randomized into the following groups 14 days after implantation: G1, control without treatment; G2, CDDP (6 mg/kg, intraperitoneal (i.p.) injection, weekly, for 2 weeks); G3, rMETase (100 unit/mouse, i.p., daily, for 2 weeks). G4, S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., weekly, for 2 weeks); G5, S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., weekly, for 2 weeks) combined with rMETase (100 unit/mouse, i.p., daily, for 2 weeks); G6, S. typhimurium A1-R (5 × 107 CFU/100 μl, i.v., weekly, for 2 weeks) combined with rMETase (100 unit/mouse, i.p., daily, for 2 weeks) and CDDP (6 mg/kg, i.p. injection, weekly, for 2 weeks). On day 14 after initiation, all treatments except CDDP alone, significantly inhibited tumor growth compared to untreated control: (CDDP: p = 0.586; rMETase: p = 0.002; S. typhimurium A1-R: p = 0.002; S. typhimurium A1-R combined with rMETase: p = 0.0004; rMETase combined with both S. typhimurium A1-R and CDDP: p = 0.0001). The decoy, trap and kill combination of S. typhimurium A1-R, rMETase and CDDP was the most effective of all therapies and was able to eradicate the metastatic osteosarcoma PDOX.

  2. Endonucleases : new tools to edit the mouse genome

    NARCIS (Netherlands)

    Wijshake, Tobias; Baker, Darren J.; van de Sluis, Bart

    2014-01-01

    Mouse transgenesis has been instrumental in determining the function of genes in the pathophysiology of human diseases and modification of genes by homologous recombination in mouse embryonic stem cells remains a widely used technology. However, this approach harbors a number of disadvantages, as it

  3. 75 FR 42114 - Office of Biotechnology Activities; Recombinant DNA Research: Proposed Action Under the NIH...

    Science.gov (United States)

    2010-07-20

    ... risk of recombination with endogenous retroviruses which could potentially result in mobilization of the transgene via a replication- competent mouse retrovirus. As the risk of recombination and possible... genetic modifications: (a) More than one-half of the genome of an exogenous virus from a single Family of...

  4. Vaccination with the recombinant chimeric antigen recNcMIC3-1-R induces a non-protective Th2-type immune response in the pregnant mouse model for N. caninum infection.

    Science.gov (United States)

    Monney, Thierry; Debache, Karim; Grandgirard, Denis; Leib, Stephen L; Hemphill, Andrew

    2012-10-12

    The major route of transmission of Neospora caninum in cattle is transplacentally from an infected cow to its progeny. Therefore, a vaccine should be able to prevent both the horizontal transmission from contaminated food or water and the vertical transmission. We have previously shown that a chimeric vaccine composed of predicted immunogenic epitopes of NcMIC3, NcMIC1 and NcROP2 (recNcMIC3-1-R) significantly reduced the cerebral infection in BALB/c mice. In this study, mice were first vaccinated, then mated and pregnant mice were challenged with 2×10(6)N. caninum tachyzoites at day 7-9 of pregnancy. Partial protection was only observed in the mice vaccinated with a tachyzoite crude protein extract but no protection against vertical transmission or cerebral infection in the dams was observed in the group vaccinated with recNcMIC3-1-R. Serological and cytokine analysis showed an overall lower cytokine level in sera associated with a dominant IL-4 expression and high IgG1 titers. Thus, the Th2-type immune response observed in the pregnant mice was not protective against experimental neosporosis, in contrary to the mixed Th1-/Th2-type immune response observed in the non-pregnant mouse model. These results demonstrate that the immunomodulation that occurs during pregnancy was not favorable for the protection against N. caninum infection conferred by vaccination with recNcMIC3-1-R. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Recombined DNA vaccines encoding calreticulin linked to HPV6bE7 enhance immune response and inhibit angiogenic activity in B16 melanoma mouse model expressing HPV 6bE7 antigen.

    Science.gov (United States)

    Zhao, Ke-Jia; Cheng, Hao; Zhu, Ke-Jian; Xu, Yan; Chen, Min-Li; Zhang, Xing; Song, Tao; Ye, Jun; Wang, Qi; Chen, Da-Fang

    2006-07-01

    Calreticulin (CRT) has been reported to have an effect of upregulating MHC class I presentation as well as inhibiting angiogenesis in vitro and in vivo. Combination of dual mechanisms of enhanced immunogenicity of human papillomavirus (HPV) 6bE7 antigen and antiangiogenesis may be introduced in the strategy of vaccines against condyloma acuminatum (CA) resulting from HPV infection. Therefore, we constructed DNA vaccines by employing different lengths of CRT chimerically linked to a model antigen HPV6bE7 and investigated the immunological and antiangiogenic effects of these vaccines in a B16 melanoma model that express HPV6bE7 antigen. Our results showed that vaccination with CRT180/HPV6bE7 or CRT120/HPV6bE7 enhanced the presence of CD8(+) T cells and TCRgammadelta T cells in vivo, increased the specific lysis activity against E7-expressing cells and secretion levels of IL-2 and IFN-gamma by activating T cells in vitro significantly. Moreover, recombined CRT180 or CRT120 with HPV6bE7 vaccines could elicit a more efficient E7-specific immune response than HPV6bE7 alone. The similarity of immunological enhancement of CRT180/HPV6bE7 and CRT120/HPV6bE7 implies that the immunologically active region mainly exist in fragment 1-120 aa. Furthermore, CRT180/HPV6bE7 and CRT180 displayed remarkable superiority over CRT120/HPV6bE7 in vivo angiogenesis assay, suggesting that the antiangiogenic activity of CRT resides in a domain between aa 120 and 180. Vaccination with CRT180/HPV6bE7 generated the best protective effect of delaying tumor formation and reduction of tumor size in tumor growth inhibition experiment among all DNA constructs. Therefore, CRT180/HPV6bE7 vaccine may enhance the immunological response to HPV6bE7 and inhibit angiogenesis. This construct may be useful in preventing HPV-associated dermatosis and may be developed as a promising strategy to control CA.

  6. Mouse phenotyping.

    Science.gov (United States)

    Fuchs, Helmut; Gailus-Durner, Valérie; Adler, Thure; Aguilar-Pimentel, Juan Antonio; Becker, Lore; Calzada-Wack, Julia; Da Silva-Buttkus, Patricia; Neff, Frauke; Götz, Alexander; Hans, Wolfgang; Hölter, Sabine M; Horsch, Marion; Kastenmüller, Gabi; Kemter, Elisabeth; Lengger, Christoph; Maier, Holger; Matloka, Mikolaj; Möller, Gabriele; Naton, Beatrix; Prehn, Cornelia; Puk, Oliver; Rácz, Ildikó; Rathkolb, Birgit; Römisch-Margl, Werner; Rozman, Jan; Wang-Sattler, Rui; Schrewe, Anja; Stöger, Claudia; Tost, Monica; Adamski, Jerzy; Aigner, Bernhard; Beckers, Johannes; Behrendt, Heidrun; Busch, Dirk H; Esposito, Irene; Graw, Jochen; Illig, Thomas; Ivandic, Boris; Klingenspor, Martin; Klopstock, Thomas; Kremmer, Elisabeth; Mempel, Martin; Neschen, Susanne; Ollert, Markus; Schulz, Holger; Suhre, Karsten; Wolf, Eckhard; Wurst, Wolfgang; Zimmer, Andreas; Hrabě de Angelis, Martin

    2011-02-01

    Model organisms like the mouse are important tools to learn more about gene function in man. Within the last 20 years many mutant mouse lines have been generated by different methods such as ENU mutagenesis, constitutive and conditional knock-out approaches, knock-down, introduction of human genes, and knock-in techniques, thus creating models which mimic human conditions. Due to pleiotropic effects, one gene may have different functions in different organ systems or time points during development. Therefore mutant mouse lines have to be phenotyped comprehensively in a highly standardized manner to enable the detection of phenotypes which might otherwise remain hidden. The German Mouse Clinic (GMC) has been established at the Helmholtz Zentrum München as a phenotyping platform with open access to the scientific community (www.mousclinic.de; [1]). The GMC is a member of the EUMODIC consortium which created the European standard workflow EMPReSSslim for the systemic phenotyping of mouse models (http://www.eumodic.org/[2]). Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Expression of Recombinant Antibodies

    OpenAIRE

    André eFrenzel; Michael eHust; Thomas eSchirrmann

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transg...

  8. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

  9. Gateway Recombinational Cloning.

    Science.gov (United States)

    Reece-Hoyes, John S; Walhout, Albertha J M

    2018-01-02

    The Gateway recombinatorial cloning system was developed for cloning multiple DNA fragments in parallel (e.g., in 96-well formats) in a standardized manner using the same enzymes. Gateway cloning is based on the highly specific integration and excision reactions of bacteriophage λ into and out of the Escherichia coli genome. Because the sites of recombination (" att " sites) are much longer (25-242 bp) than restriction sites, they are extremely unlikely to occur by chance in DNA fragments. Therefore, the same recombination enzyme can be used to robustly clone many different fragments of variable size in parallel reactions. © 2018 Cold Spring Harbor Laboratory Press.

  10. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  11. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  12. Mouse adhalin

    DEFF Research Database (Denmark)

    Liu, L; Vachon, P H; Kuang, W

    1997-01-01

    Adhalin, or alpha-sarcoglycan, is a 50-kDa glycoprotein that was originally characterized as a muscle membrane protein. The importance of adhalin is suggested by the diseases associated with its absence, notably the limb-girdle muscular dystrophies. However, the function of adhalin is unknown...... was specifically expressed in striated muscle cells and their immediate precursors, and absent in many other cell types. Adhalin expression in embryonic mouse muscle was coincident with primary myogenesis. Its expression was found to be up-regulated at mRNA and protein levels during myogenic differentiation...... in vitro. The proper localization of adhalin to the muscle cell membrane was observed only in late stages of myotube maturation, coincident with the re-distribution of caveolin-3 and dystrophin. These data suggest that adhalin is highly specific for striated muscle and that it is linked with the formation...

  13. Bacterial Recombineering: Genome Engineering via Phage-Based Homologous Recombination.

    Science.gov (United States)

    Pines, Gur; Freed, Emily F; Winkler, James D; Gill, Ryan T

    2015-11-20

    The ability to specifically modify bacterial genomes in a precise and efficient manner is highly desired in various fields, ranging from molecular genetics to metabolic engineering and synthetic biology. Much has changed from the initial realization that phage-derived genes may be employed for such tasks to today, where recombineering enables complex genetic edits within a genome or a population. Here, we review the major developments leading to recombineering becoming the method of choice for in situ bacterial genome editing while highlighting the various applications of recombineering in pushing the boundaries of synthetic biology. We also present the current understanding of the mechanism of recombineering. Finally, we discuss in detail issues surrounding recombineering efficiency and future directions for recombineering-based genome editing.

  14. Protective efficacy of a recombinant Newcastle disease virus expressing glycoprotein of vesicular stomatitis virus in mice

    OpenAIRE

    Zhang, Minmin; Ge, Jinying; Li, Xiaofang; Chen, Weiye; Wang, Xijun; Wen, Zhiyuan; Bu, Zhigao

    2016-01-01

    Background Vesicular stomatitis virus (VSV) causes severe losses to the animal husbandry industry. In this study, a recombinant Newcastle disease virus (NDV) expressing the glycoprotein (G) of VSV (rL-VSV-G) was constructed and its pathogenicity and immune protective efficacy in mouse were evaluated. Results In pathogenicity evaluation test, the analysis of the viral distribution in mouse organs and body weight change showed that rL-VSV-G was safe in mice. In immune protection assay, the reco...

  15. Temporally-controlled site-specific recombination in zebrafish.

    Directory of Open Access Journals (Sweden)

    Stefan Hans

    Full Text Available Conventional use of the site-specific recombinase Cre is a powerful technology in mouse, but almost absent in other vertebrate model organisms. In zebrafish, Cre-mediated recombination efficiency was previously very low. Here we show that using transposon-mediated transgenesis, Cre is in fact highly efficient in this organism. Furthermore, temporal control of recombination can be achieved by using the ligand-inducible CreER(T2. Site-specific recombination only occurs upon administration of the drug tamoxifen (TAM or its active metabolite, 4-hydroxy-tamoxifen (4-OHT. Cre-mediated recombination is detectable already 4 or 2 hours after administration of TAM or 4-OHT, demonstrating fast recombination kinetics. In addition, low doses of TAM allow mosaic labeling of single cells. Combined, our results show that conditional Cre/lox will be a valuable tool for both, embryonic and adult zebrafish studies. Furthermore, single copy insertion transgenesis of Cre/lox constructs suggest a strategy suitable also for other organisms.

  16. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

    Full Text Available Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with human-like post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

  17. Expression of Recombinant Antibodies

    Science.gov (United States)

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications. PMID:23908655

  18. Dissociative recombination of HCl+

    Science.gov (United States)

    Larson, Åsa; Fonseca dos Santos, Samantha; E. Orel, Ann

    2017-08-01

    The dissociative recombination of HCl+, including both the direct and indirect mechanisms, is studied. For the direct process, the relevant electronic states are calculated ab initio by combining electron scattering calculations to obtain resonance positions and autoionization widths with multi-reference configuration interaction calculations of the ion and Rydberg states. The cross section for the direct dissociation along electronic resonant states is computed by solution of the time-dependent Schrödinger equation. For the indirect process, an upper bound value for the cross section is obtained using a vibrational frame transformation of the elements of the scattering matrix at energies just above the ionization threshold. Vibrational excitations of the ionic core from the ground vibrational state, v = 0 , to the first three excited vibrational states, v = 1 , v = 2 , and v = 3 , are considered. Autoionization is neglected and the effect of the spin-orbit splitting of the ionic potential energy upon the indirect dissociative recombination cross section is considered. The calculated cross sections are compared to measurements.

  19. Simple and efficient expression of codon-optimized mouse leukemia ...

    African Journals Online (AJOL)

    Purpose: To obtain a higher yield of mouse leukemia inhibitory factor to maintain the proliferation potential of pluripotent stem cells at a low cost. Methods: A method was designed to produce recombinant mLIF protein (rmLIF) in Escherichia coli. Through analysis of rmLIF sequence, it was found that rare codons were ...

  20. Creating Porcine Biomedical Models Through Recombineering

    Directory of Open Access Journals (Sweden)

    Lawrence B. Schook

    2006-03-01

    Full Text Available Recent advances in genomics provide genetic information from humans and other mammals (mouse, rat, dog and primates traditionally used as models as well as new candidates (pigs and cattle. In addition, linked enabling technologies, such as transgenesis and animal cloning, provide innovative ways to design and perform experiments to dissect complex biological systems. Exploitation of genomic information overcomes the traditional need to choose naturally occurring models. Thus, investigators can utilize emerging genomic knowledge and tools to create relevant animal models. This approach is referred to as reverse genetics. In contrast to ‘forward genetics’, in which gene(s responsible for a particular phenotype are identified by positional cloning (phenotype to genotype, the ‘reverse genetics’ approach determines the function of a gene and predicts the phenotype of a cell, tissue, or organism (genotype to phenotype. The convergence of classical and reverse genetics, along with genomics, provides a working definition of a ‘genetic model’ organism (3. The recent construction of phenotypic maps defining quantitative trait loci (QTL in various domesticated species provides insights into how allelic variations contribute to phenotypic diversity. Targeted chromosomal regions are characterized by the construction of bacterial artificial chromosome (BAC contigs to isolate and characterize genes contributing towards phenotypic variation. Recombineering provides a powerful methodology to harvest genetic information responsible for phenotype. Linking recombineering with gene-targeted homologous recombination, coupled with nuclear transfer (NT technology can provide ‘clones’ of genetically modified animals.

  1. Microbial factories for recombinant pharmaceuticals

    National Research Council Canada - National Science Library

    Ferrer-Miralles, Neus; Domingo-Espín, Joan; Corchero, José Luis; Vázquez, Esther; Villaverde, Antonio

    2009-01-01

    ...-translational modifications, proteolytic instability, poor solubility and activation of cell stress responses, among others, they represent convenient and powerful tools for recombinant protein production...

  2. Two Mutually Exclusive Local Chromatin States Drive Efficient V(DJ Recombination

    Directory of Open Access Journals (Sweden)

    Daniel J. Bolland

    2016-06-01

    Full Text Available Variable (V, diversity (D, and joining (J (V(DJ recombination is the first determinant of antigen receptor diversity. Understanding how recombination is regulated requires a comprehensive, unbiased readout of V gene usage. We have developed VDJ sequencing (VDJ-seq, a DNA-based next-generation-sequencing technique that quantitatively profiles recombination products. We reveal a 200-fold range of recombination efficiency among recombining V genes in the primary mouse Igh repertoire. We used machine learning to integrate these data with local chromatin profiles to identify combinatorial patterns of epigenetic features that associate with active VH gene recombination. These features localize downstream of VH genes and are excised by recombination, revealing a class of cis-regulatory element that governs recombination, distinct from expression. We detect two mutually exclusive chromatin signatures at these elements, characterized by CTCF/RAD21 and PAX5/IRF4, which segregate with the evolutionary history of associated VH genes. Thus, local chromatin signatures downstream of VH genes provide an essential layer of regulation that determines recombination efficiency.

  3. Two Mutually Exclusive Local Chromatin States Drive Efficient V(D)J Recombination.

    Science.gov (United States)

    Bolland, Daniel J; Koohy, Hashem; Wood, Andrew L; Matheson, Louise S; Krueger, Felix; Stubbington, Michael J T; Baizan-Edge, Amanda; Chovanec, Peter; Stubbs, Bryony A; Tabbada, Kristina; Andrews, Simon R; Spivakov, Mikhail; Corcoran, Anne E

    2016-06-14

    Variable (V), diversity (D), and joining (J) (V(D)J) recombination is the first determinant of antigen receptor diversity. Understanding how recombination is regulated requires a comprehensive, unbiased readout of V gene usage. We have developed VDJ sequencing (VDJ-seq), a DNA-based next-generation-sequencing technique that quantitatively profiles recombination products. We reveal a 200-fold range of recombination efficiency among recombining V genes in the primary mouse Igh repertoire. We used machine learning to integrate these data with local chromatin profiles to identify combinatorial patterns of epigenetic features that associate with active VH gene recombination. These features localize downstream of VH genes and are excised by recombination, revealing a class of cis-regulatory element that governs recombination, distinct from expression. We detect two mutually exclusive chromatin signatures at these elements, characterized by CTCF/RAD21 and PAX5/IRF4, which segregate with the evolutionary history of associated VH genes. Thus, local chromatin signatures downstream of VH genes provide an essential layer of regulation that determines recombination efficiency. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model

    National Research Council Canada - National Science Library

    Ai, Chunqing; Zhang, Qiuxiang; Ren, Chengcheng; Wang, Gang; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Chen, Yong Q; Chen, Wei

    2014-01-01

    .... Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model...

  5. Mouse embryonic stem cells with a multi-integrase mouse artificial chromosome for transchromosomic mouse generation.

    Science.gov (United States)

    Yoshimura, Yuki; Nakamura, Kazuomi; Endo, Takeshi; Kajitani, Naoyo; Kazuki, Kanako; Kazuki, Yasuhiro; Kugoh, Hiroyuki; Oshimura, Mitsuo; Ohbayashi, Tetsuya

    2015-08-01

    The mouse artificial chromosome (MAC) has several advantages as a gene delivery vector, including stable episomal maintenance of the exogenous genetic material and the ability to carry large and/or multiple gene inserts including their regulatory elements. Previously, a MAC containing multi-integration site (MI-MAC) was generated to facilitate transfer of multiple genes into desired cells. To generate transchromosomic (Tc) mice containing a MI-MAC with genes of interest, the desired genes were inserted into MI-MAC in CHO cells, and then the MI-MAC was transferred to mouse embryonic stem (mES) cells via microcell-mediated chromosome transfer (MMCT). However, the efficiency of MMCT from CHO to mES cells is very low (lines containing a MI-MAC vector to directly insert a gene of interest into the MI-MAC in mES cells via a simple transfection method for Tc mouse generation. The recombination rate of the GFP gene at each attachment site (FRT, PhiC31attP, R4attP, TP901-1attP and Bxb1attP) on MI-MAC was greater than 50% in MI-MAC mES cells. Chimeric mice with high coat colour chimerism were generated from the MI-MAC mES cell lines and germline transmission from the chimera was observed. As an example for the generation of Tc mice with a desired gene by the MI-MAC mES approach, a Tc mouse strain ubiquitously expressing Emerald luciferase was efficiently established. Thus, the findings suggest that this new Tc strategy employing mES cells and a MI-MAC vector is efficient and useful for animal transgenesis.

  6. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as w...

  7. Centralized mouse repositories.

    Science.gov (United States)

    Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

    2012-10-01

    Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

  8. A simple DNA recombination screening method by RT-PCR as an alternative to Southern blot

    DEFF Research Database (Denmark)

    Albers, Eliene; Sbroggiò, Mauro; Martin Gonzalez, Javier

    2017-01-01

    The generation of genetically engineered mouse models (GEMMs), including knock-out (KO) and knock-in (KI) models, often requires genomic screening of many mouse ES cell (mESC) clones by Southern blot. The use of large targeting constructs facilitates the recombination of exogenous DNA in a specific...... many false positive and false negative results. Here, we propose an alternative screening method based on the detection of a genetic modification at the mRNA level, which we successfully optimized in two mouse models. This screening method consists of a reverse-transcription PCR (RT-PCR) using primers...... that match exons flanking the targeting construct. The detection of the expected modification in this PCR product confirms the integration at the correct genomic location and shows that the mutant mRNA is expressed. This is a simple and sensitive strategy to screen locus-specific recombination of targeting...

  9. A systematic analysis of recombination activity and genotype-phenotype correlation in human recombination-activating gene 1 deficiency.

    Science.gov (United States)

    Lee, Yu Nee; Frugoni, Francesco; Dobbs, Kerry; Walter, Jolan E; Giliani, Silvia; Gennery, Andrew R; Al-Herz, Waleed; Haddad, Elie; LeDeist, Francoise; Bleesing, Jack H; Henderson, Lauren A; Pai, Sung-Yun; Nelson, Robert P; El-Ghoneimy, Dalia H; El-Feky, Reem A; Reda, Shereen M; Hossny, Elham; Soler-Palacin, Pere; Fuleihan, Ramsay L; Patel, Niraj C; Massaad, Michel J; Geha, Raif S; Puck, Jennifer M; Palma, Paolo; Cancrini, Caterina; Chen, Karin; Vihinen, Mauno; Alt, Frederick W; Notarangelo, Luigi D

    2014-04-01

    The recombination-activating gene (RAG) 1/2 proteins play a critical role in the development of T and B cells by initiating the VDJ recombination process that leads to generation of a broad T-cell receptor (TCR) and B-cell receptor repertoire. Pathogenic mutations in the RAG1/2 genes result in various forms of primary immunodeficiency, ranging from T(-)B(-) severe combined immune deficiency to delayed-onset disease with granuloma formation, autoimmunity, or both. It is not clear what contributes to such heterogeneity of phenotypes. We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations. We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1(-/-) pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology. Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity. Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  10. No evidence of non-homologous insertions in mouse model of MDD created by replacement of homologous mouse DNA sequence with pathogenic 6-base human CREB1 promoter sequence.

    Science.gov (United States)

    Zubenko, George S; Hughes, Hugh B

    2012-01-01

    We have recently reported the creation and initial characterization of the first etiology-based recombinant mouse model of major depressive disorder (MDD). This was achieved by replacing the corresponding mouse DNA sequence with a 6-base DNA sequence from the human CREB1 promoter that is associated with the development of MDD in families identified by probands with recurrent, early-onset MDD. The current study explored whether the desired homologous recombination event at the mouse Creb1 gene that resulted in the creation of the mouse model was also accompanied by insertions of the targeting vector at unintended non-homologous locations in the mouse genome. No evidence of insertions of targeting vector sequence was observed at regions other than the mouse Creb1 gene. Copyright © 2011 Wiley Periodicals, Inc.

  11. Immunomodulatory effects of recombinant lactoferrin during MRSA infection

    Science.gov (United States)

    Hwang, Shen-An; Kruzel, Marian L.; Actor, Jeffrey K.

    2014-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection remains a serious hazard to global health despite increases in public education and development of innovative treatment strategies. Use of immune modulatory therapy to combat infection is gaining interest as a novel treatment alternative. Lactoferrin (LF), an iron binding protein with multiple immune modulating properties, has the potential to modify the course of systemic MRSA infection. Specifically, LF is capable of limiting deleterious inflammatory responses while promoting development of antigen specific T-cell activity. The efficacy of a novel recombinant mouse LF (rmLF) to protect against MRSA infection was examined in a mouse peritonitis model. BALB/c mice were infected with a lethal dose of MRSA and treated at 2 hours post-infection with rmLF. The effects of rmLF on MRSA-infected primary monocytes and granulocytes were analyzed for inflammatory mediator production. The rmLF treated mice demonstrated only modest increase in survival by more than 24hrs, albeit with reduced bacteremia. Serum cytokines, IL-17 and IL-6, were significantly reduced post challenge in the rmLF treated mice. Treatment with rmLF led to a minor decrease in IL-1β, and a slight increase in TNF-α production. Preliminary investigation towards human clinical relevance was accomplished using human blood derived monocytes and granulocytes infected with MRSA and treated with a homologous recombinant human LF (rhLF). Treatment with (rhLF) led to increased production of IFN-γ and IL-2. The human cell studies also showed a concurrent decrease in TNF-α, IL-6, IL-1β, IL-12p40, and IL-10. The study reports the first investigation into the efficacy of a novel recombinant mouse lactoferrin (LF) therapy in a mouse model of MRSA peritonitis. Overall, these results indicate the rmLF and rhLF have a high degree of overlap to modify inflammatory responses, although differences in activities were observed indicating existence of mechanisms

  12. Controlled release from recombinant polymers.

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-09-28

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Three Decades of Recombinant DNA.

    Science.gov (United States)

    Palmer, Jackie

    1985-01-01

    Discusses highlights in the development of genetic engineering, examining techniques with recombinant DNA, legal and ethical issues, GenBank (a national database of nucleic acid sequences), and other topics. (JN)

  14. Controlled Release from Recombinant Polymers

    Science.gov (United States)

    Price, Robert; Poursaid, Azadeh; Ghandehari, Hamidreza

    2014-01-01

    Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed. PMID:24956486

  15. Recombinant snake venom prothrombin activators

    OpenAIRE

    L?vgren, Ann

    2012-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

  16. Heterogeneity in recombinant protein production

    DEFF Research Database (Denmark)

    Schalén, Martin; Johanson, Ted; Lundin, Luisa

    2012-01-01

    contribute to make a population in a fermenter heterogeneous, resulting in cell-to-cell variation in physiological parameters of the microbial culture. Our study aims at investigating how population heterogeneity and recombinant protein production is affected by environmental gradients in bioreactors...... are simulated in small bioreactors and the population heterogeneity can be visualised by analysing single cells with flow cytometry. This can give new insights to cell physiology and recombinant protein production at the industrial scale....

  17. A Mouse Model of Chronic West Nile Virus Disease.

    Directory of Open Access Journals (Sweden)

    Jessica B Graham

    2016-11-01

    Full Text Available Infection with West Nile virus (WNV leads to a range of disease outcomes, including chronic infection, though lack of a robust mouse model of chronic WNV infection has precluded identification of the immune events contributing to persistent infection. Using the Collaborative Cross, a population of recombinant inbred mouse strains with high levels of standing genetic variation, we have identified a mouse model of persistent WNV disease, with persistence of viral loads within the brain. Compared to lines exhibiting no disease or marked disease, the F1 cross CC(032x013F1 displays a strong immunoregulatory signature upon infection that correlates with restraint of the WNV-directed cytolytic response. We hypothesize that this regulatory T cell response sufficiently restrains the immune response such that a chronic infection can be maintained in the CNS. Use of this new mouse model of chronic neuroinvasive virus will be critical in developing improved strategies to prevent prolonged disease in humans.

  18. RECOMBINANT HORSERADISH PEROXIDASE FOR ANALYTICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    А.M. Egorov

    2012-08-01

    Full Text Available The article deals with prospects of using recombinant horseradish peroxidase in analytical biochemistry and biotechnology. Problems of recombinant horseradish peroxidase cloning in different expression systems, possible approaches to their solution, advantages of recombinant recombinant horseradish peroxidase and recombinant horseradish peroxidase-fusion proteins for immunoassays are considered. Possibility for development of mediatorless bienzyme biosensor for peroxide and metabolites, yielding hydrogen peroxide during their transformations, based on co-adsorption of recombinant horseradish peroxidase and the appropriate oxidase was demonstrated. The possibility to produce a fully active recombinant conjugate of recombinant horseradish peroxidase with human heart-type fatty acid binding protein, which may be used in competitive immunoassay for clinical diagnosis of acute myocardial infarction, and recombinant conjugates (N- and C-terminus of recombinant horseradish peroxidase with Fab-fragments of the antibody against atrazine, which may be applied for atrazine pesticides detection, are demonstra ted for the first time.

  19. Recombination drives vertebrate genome contraction.

    Science.gov (United States)

    Nam, Kiwoong; Ellegren, Hans

    2012-01-01

    Selective and/or neutral processes may govern variation in DNA content and, ultimately, genome size. The observation in several organisms of a negative correlation between recombination rate and intron size could be compatible with a neutral model in which recombination is mutagenic for length changes. We used whole-genome data on small insertions and deletions within transposable elements from chicken and zebra finch to demonstrate clear links between recombination rate and a number of attributes of reduced DNA content. Recombination rate was negatively correlated with the length of introns, transposable elements, and intergenic spacer and with the rate of short insertions. Importantly, it was positively correlated with gene density, the rate of short deletions, the deletion bias, and the net change in sequence length. All these observations point at a pattern of more condensed genome structure in regions of high recombination. Based on the observed rates of small insertions and deletions and assuming that these rates are representative for the whole genome, we estimate that the genome of the most recent common ancestor of birds and lizards has lost nearly 20% of its DNA content up until the present. Expansion of transposable elements can counteract the effect of deletions in an equilibrium mutation model; however, since the activity of transposable elements has been low in the avian lineage, the deletion bias is likely to have had a significant effect on genome size evolution in dinosaurs and birds, contributing to the maintenance of a small genome. We also demonstrate that most of the observed correlations between recombination rate and genome contraction parameters are seen in the human genome, including for segregating indel polymorphisms. Our data are compatible with a neutral model in which recombination drives vertebrate genome size evolution and gives no direct support for a role of natural selection in this process.

  20. Recombination in the human Pseudoautosomal region PAR1.

    Directory of Open Access Journals (Sweden)

    Anjali G Hinch

    2014-07-01

    Full Text Available The pseudoautosomal region (PAR is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  1. A systematic investigation of production of synthetic prions from recombinant prion protein.

    Science.gov (United States)

    Schmidt, Christian; Fizet, Jeremie; Properzi, Francesca; Batchelor, Mark; Sandberg, Malin K; Edgeworth, Julie A; Afran, Louise; Ho, Sammy; Badhan, Anjna; Klier, Steffi; Linehan, Jacqueline M; Brandner, Sebastian; Hosszu, Laszlo L P; Tattum, M Howard; Jat, Parmjit; Clarke, Anthony R; Klöhn, Peter C; Wadsworth, Jonathan D F; Jackson, Graham S; Collinge, John

    2015-12-01

    According to the protein-only hypothesis, infectious mammalian prions, which exist as distinct strains with discrete biological properties, consist of multichain assemblies of misfolded cellular prion protein (PrP). A critical test would be to produce prion strains synthetically from defined components. Crucially, high-titre 'synthetic' prions could then be used to determine the structural basis of infectivity and strain diversity at the atomic level. While there have been multiple reports of production of prions from bacterially expressed recombinant PrP using various methods, systematic production of high-titre material in a form suitable for structural analysis remains a key goal. Here, we report a novel high-throughput strategy for exploring a matrix of conditions, additives and potential cofactors that might generate high-titre prions from recombinant mouse PrP, with screening for infectivity using a sensitive automated cell-based bioassay. Overall, approximately 20,000 unique conditions were examined. While some resulted in apparently infected cell cultures, this was transient and not reproducible. We also adapted published methods that reported production of synthetic prions from recombinant hamster PrP, but again did not find evidence of significant infectious titre when using recombinant mouse PrP as substrate. Collectively, our findings are consistent with the formation of prion infectivity from recombinant mouse PrP being a rare stochastic event and we conclude that systematic generation of prions from recombinant PrP may only become possible once the detailed structure of authentic ex vivo prions is solved. © 2015 The Authors.

  2. Dissociative Recombination of Complex Ions

    Science.gov (United States)

    Mitchell, J. Brian A.

    1999-10-01

    The FALP-MS apparatus at the University of Rennes allows the measurement of rate coefficients for the recombination of molecular ions to be made (at 300K) even though several ions may be present in the afterglow. The recombination of a number of hydrocarbon ions derived from alkane ( Lehfaoui et al. J. Chem. Phys. 106, 5406, 1997.), alkene ( Rebrion-Rowe et al. J. Chem. Phys. 108, 7185, 1998.) and aromatic (Rebrion-Rowe et al. (Submitted to J. Chem. Phys.)) parent molecules has been studied. Despite the wide range of complexity of these compounds, the measured recombination rates are remarkably similar having values in the range of 4-10-7 cm^3.s-1. Plans are being laid for a new version of this apparatus that will allow pre-prepared ions to be injected into the inert buffer gas flow. This will allow reactive ions to be studied as well as halogen containing ions whose recombination rates would normally be masked by electron attachment to their parent gases in a conventional flowing afterglow apparatus. A high temperature modification to the CRESU supersonic flow apparatus (J.L. Le Garrec et al. J. Chem. Phys. 107, 54, 1997.) in our laboratory will allow electron attachment to radicals to be studied by means of the mass spectrometric detection of products, Langmuir probe measurement of the electron density in the flow and Laser Induced Fluorescent identification of the radical species. Such measurements are needed for the modeling of semiconductor processing plasmas.

  3. Influenza Vaccine, Inactivated or Recombinant

    Science.gov (United States)

    ... die from flu, and many more are hospitalized.Flu vaccine can:keep you from getting flu, make flu ... What is inactivated or recombinant influenza vaccine?A dose of flu vaccine is recommended every flu season. Children 6 months through 8 years of age may need two ...

  4. Molecular Mechanism for Genetic Recombination

    Science.gov (United States)

    Sobell, Henry M.

    1972-01-01

    Symmetry considerations of proteinnucleic acid interaction suggest the existence of an alternate branched configuration for DNA induced by binding specific structural proteins to symmetrically arranged polynucleotide base sequences. The concept that such sequences exist at the ends of genes or operons leads to a molecular model for genetic recombination in eukaryotic cells. PMID:4115953

  5. Genetic recombination and molecular evolution.

    Science.gov (United States)

    Charlesworth, B; Betancourt, A J; Kaiser, V B; Gordo, I

    2009-01-01

    Reduced rates of genetic recombination are often associated with reduced genetic variability and levels of adaptation. Several different evolutionary processes, collectively known as Hill-Robertson (HR) effects, have been proposed as causes of these correlates of recombination. Here, we use DNA sequence polymorphism and divergence data from the noncrossing over dot chromosome of Drosophila to discriminate between two of the major forms of HR effects: selective sweeps and background selection. This chromosome shows reduced levels of silent variability and reduced effectiveness of selection. We show that neither model fits the data on variability. We propose that, in large genomic regions with restricted recombination, HR effects among nonsynonymous mutations undermine the effective strength of selection, so that their background selection effects are weakened. This modified model fits the data on variability and also explains why variability in very large nonrecombining genomes is not completely wiped out. We also show that HR effects of this type can produce an individual selection advantage to recombination, as well as greatly reduce the mean fitness of nonrecombining genomes and genomic regions.

  6. Recombination in immunoglobulin gene loci

    Directory of Open Access Journals (Sweden)

    Komisarenko S. V.

    2009-02-01

    Full Text Available Gene network of the lymphoid cell differentiation coordinates precisely the recombination process in immunoglobulin gene loci. In our opinion, cellular microRNAs can contribute to the allelic exclusion through microRNA-directed DNA methylation and participate in retargeting recombinases activity from the gene loci of heavy immunoglobulin chains to the gene loci of light chains

  7. Mouse models of cataract

    Indian Academy of Sciences (India)

    2009-12-31

    Dec 31, 2009 ... Much of our knowledge about the function of genes in cataracts has been derived from the molecular analysis of spontaneous or induced mutations in the mouse. Mutations affecting the mouse lens can be identified easily by visual inspection, and a remarkable number of mutant lines have been ...

  8. Gaze beats mouse

    DEFF Research Database (Denmark)

    Mateo, Julio C.; San Agustin, Javier; Hansen, John Paulin

    2008-01-01

    Facial EMG for selection is fast, easy and, combined with gaze pointing, it can provide completely hands-free interaction. In this pilot study, 5 participants performed a simple point-and-select task using mouse or gaze for pointing and a mouse button or a facial-EMG switch for selection. Gaze po...

  9. Initiation of meiotic recombination in Ustilago maydis

    National Research Council Canada - National Science Library

    Kojic, Milorad; Sutherland, Jeanette H; Pérez-Martín, José; Holloman, William K

    2013-01-01

    .... Ustilago maydis, a biotrophic fungus that parasitizes maize, has long been utilized as an experimental system for studying recombination, but it has not been clear when in the life cycle meiotic recombination initiates. U...

  10. GARD: a genetic algorithm for recombination detection

    National Research Council Canada - National Science Library

    Kosakovsky Pond, Sergei L; Posada, David; Gravenor, Michael B; Woelk, Christopher H; Frost, Simon D W

    2006-01-01

    .... We developed a likelihood-based model selection procedure that uses a genetic algorithm to search multiple sequence alignments for evidence of recombination breakpoints and identify putative recombinant sequences...

  11. Sequence, molecular properties, and chromosomal mapping of mouse lumican

    Science.gov (United States)

    Funderburgh, J. L.; Funderburgh, M. L.; Hevelone, N. D.; Stech, M. E.; Justice, M. J.; Liu, C. Y.; Kao, W. W.; Conrad, G. W.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    PURPOSE. Lumican is a major proteoglycan of vertebrate cornea. This study characterizes mouse lumican, its molecular form, cDNA sequence, and chromosomal localization. METHODS. Lumican sequence was determined from cDNA clones selected from a mouse corneal cDNA expression library using a bovine lumican cDNA probe. Tissue expression and size of lumican mRNA were determined using Northern hybridization. Glycosidase digestion followed by Western blot analysis provided characterization of molecular properties of purified mouse corneal lumican. Chromosomal mapping of the lumican gene (Lcn) used Southern hybridization of a panel of genomic DNAs from an interspecific murine backcross. RESULTS. Mouse lumican is a 338-amino acid protein with high-sequence identity to bovine and chicken lumican proteins. The N-terminus of the lumican protein contains consensus sequences for tyrosine sulfation. A 1.9-kb lumican mRNA is present in cornea and several other tissues. Antibody against bovine lumican reacted with recombinant mouse lumican expressed in Escherichia coli and also detected high molecular weight proteoglycans in extracts of mouse cornea. Keratanase digestion of corneal proteoglycans released lumican protein, demonstrating the presence of sulfated keratan sulfate chains on mouse corneal lumican in vivo. The lumican gene (Lcn) was mapped to the distal region of mouse chromosome 10. The Lcn map site is in the region of a previously identified developmental mutant, eye blebs, affecting corneal morphology. CONCLUSIONS. This study demonstrates sulfated keratan sulfate proteoglycan in mouse cornea and describes the tools (antibodies and cDNA) necessary to investigate the functional role of this important corneal molecule using naturally occurring and induced mutants of the murine lumican gene.

  12. Promiscuous recombination of LoxP alleles during gametogenesis in cornea Cre driver mice

    Science.gov (United States)

    Weng, Daniel Y.; Zhang, Yujin; Hayashi, Yasuhito; Kuan, Chia-Yi; Liu, Chia-Yang; Babcock, George; Weng, Wei-Lan; Schwemberger, Sandy

    2008-01-01

    Purpose To examine whether promiscuous Cre/LoxP recombination happens during gametogenesis in double transgenic mice carrying LoxP modified alleles and Cre transgene driven by tissue-specific promoter outside the gonads of adult mice. Methods Cre driver mice were crossbred with reporter mouse lines (e.g., ZEG and Rosa26R) to obtain Cre/ZEG and Cre/Rosa26R double transgenic mice. The frequency of promiscuous LoxP/Cre recombination was determined by the expression of second reporter genes in the offspring of double transgenic mice. Results The frequency of promiscuous LoxP/Cre recombination varied in different lines of Cre driver mice and in the sex of the same driver mice with higher penetrance in male than in female double transgenic mice. Polymerase chain reaction (PCR) and recombination analysis demonstrate that the recombination of floxed allele occurs during the transition from spermatogonia (diploid) to primary spermatocyte (tetraploid) in the testis. Thereby, target-floxed allele(s) may be ubiquitously ablated in experimental animals intended for tissue-specific gene deletion. Conclusions Gametogenesis-associated recombination should always be examined in tissue-specific gene ablation studies. PMID:18385792

  13. Is the segmented plasma excitation recombination laser a recombination laser

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V.V.; Sirotkin, A.A. (Institut Obshchei Fiziki, Moscow (USSR))

    1989-10-01

    The role of plasmachemical reactions in the formation of active media in lasers with a sectional plasma source for metal vapor is investigated. It is shown that the population of ionic levels in Cd II and Zn II occurs under recharging with He(+) and in the process of Penning ionization. It is found that these processes are more efficient than recombination and electron impact. 13 refs.

  14. Interhomolog recombination and loss of heterozygosity in wild-type and Bloom syndrome helicase (BLM)-deficient mammalian cells.

    Science.gov (United States)

    LaRocque, Jeannine R; Stark, Jeremy M; Oh, Jin; Bojilova, Ekaterina; Yusa, Kosuke; Horie, Kyoji; Takeda, Junji; Jasin, Maria

    2011-07-19

    Genomic integrity often is compromised in tumor cells, as illustrated by genetic alterations leading to loss of heterozygosity (LOH). One mechanism of LOH is mitotic crossover recombination between homologous chromosomes, potentially initiated by a double-strand break (DSB). To examine LOH associated with DSB-induced interhomolog recombination, we analyzed recombination events using a reporter in mouse embryonic stem cells derived from F1 hybrid embryos. In this study, we were able to identify LOH events although they occur only rarely in wild-type cells (≤2.5%). The low frequency of LOH during interhomolog recombination suggests that crossing over is rare in wild-type cells. Candidate factors that may suppress crossovers include the RecQ helicase deficient in Bloom syndrome cells (BLM), which is part of a complex that dissolves recombination intermediates. We analyzed interhomolog recombination in BLM-deficient cells and found that, although interhomolog recombination is slightly decreased in the absence of BLM, LOH is increased by fivefold or more, implying significantly increased interhomolog crossing over. These events frequently are associated with a second homologous recombination event, which may be related to the mitotic bivalent structure and/or the cell-cycle stage at which the initiating DSB occurs.

  15. Caffeine suppresses homologous recombination through interference with RAD51-mediated joint molecule formation

    Science.gov (United States)

    Zelensky, Alex N.; Sanchez, Humberto; Ristic, Dejan; Vidic, Iztok; van Rossum-Fikkert, Sari E.; Essers, Jeroen; Wyman, Claire; Kanaar, Roland

    2013-01-01

    Caffeine is a widely used inhibitor of the protein kinases that play a central role in the DNA damage response. We used chemical inhibitors and genetically deficient mouse embryonic stem cell lines to study the role of DNA damage response in stable integration of the transfected DNA and found that caffeine rapidly, efficiently and reversibly inhibited homologous integration of the transfected DNA as measured by several homologous recombination-mediated gene-targeting assays. Biochemical and structural biology experiments revealed that caffeine interfered with a pivotal step in homologous recombination, homologous joint molecule formation, through increasing interactions of the RAD51 nucleoprotein filament with non-homologous DNA. Our results suggest that recombination pathways dependent on extensive homology search are caffeine-sensitive and stress the importance of considering direct checkpoint-independent mechanisms in the interpretation of the effects of caffeine on DNA repair. PMID:23666627

  16. Microbial factories for recombinant pharmaceuticals

    OpenAIRE

    Domingo-Espín Joan; Ferrer-Miralles Neus; Corchero José; Vázquez Esther; Villaverde Antonio

    2009-01-01

    Abstract Most of the hosts used to produce the 151 recombinant pharmaceuticals so far approved for human use by the Food and Drug Administration (FDA) and/or by the European Medicines Agency (EMEA) are microbial cells, either bacteria or yeast. This fact indicates that despite the diverse bottlenecks and obstacles that microbial systems pose to the efficient production of functional mammalian proteins, namely lack or unconventional post-translational modifications, proteolytic instability, po...

  17. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  18. Production systems for recombinant antibodies.

    Science.gov (United States)

    Schirrmann, Thomas; Al-Halabi, Laila; Dübel, Stefan; Hust, Michael

    2008-05-01

    Recombinant antibodies are the fastest growing class of therapeutic proteins. Furthermore, antibodies are key detection reagents in research and diagnostics. The increasing demand for antibodies with regards to amount and quality resulted in the development of a variety of recombinant production systems employing gram-negative and gram-positive bacteria, yeast and filamentous fungi, insect cell lines as well as mammalian cell lines. More recently, antibodies were also successfully produced in transgenic plants and animals. Currently, the production of recombinant antibodies for therapy is performed in mammalian cell lines to reduce the risk of immunogenicity caused by non-human post-translational modifications, in particular glycosylation. However, novel strategies already allow human-like glycosylation patterns in yeast, insect cell lines and transgenic plants. Furthermore, therapeutic strategies not requiring glycosylation of the Fc portion have been conceived, most prominently using bispecific antibodies or scFv fusion proteins, which can be produced in bacteria. Here, we review all current antibody production systems considering their advantages and limitations with respect to intended applications.

  19. Nondisjunction of chromosome 15: Origin and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A.; Mutirangura, A.; Ledbetter, D.H. (Baylor College of Medicine, Houston, TX (United States)); Langlois, S. (Univ. of Britisch Columbia, Vancouver (Canada)); Morris, M.A.; Malcolm, S.

    1993-09-01

    Thirty-two cases of uniparental disomy (UPD), ascertained from Prader-Willi syndrome patients (N=27) and Angelman syndrome patients (N-5), are used to investigate the pattern of recombination associated with nondisjunction of chromosome 15. In addition, the meiotic stage of nondisjunction is inferred by using markers mapping near the centromere. Two basic approaches to the analysis of recombination in specific pairwise intervals along the chromosome. This method shows a significant reduction in recombination for two of five intervals examined. Second, the observed frequency of each recombinant class (i.e., zero, one, two, three, or more observable crossovers) is compared with expected values. This is useful for testing whether the reduction in recombination can be attributed solely to a proportion of cases with no recombination at all (because of asynapsis), with the remaining groups showing normal recombination (or even excess recombination), or whether recombination is uniformly reduced. Analysis of maternal UPD(15) data shows a slight reduction in the multiple-recombinant classes, with a corresponding increase in both the zero- and one-recombinant classes over expected values. The majority, more than 82%, of the extra chromosomes in maternal UPD(15) cases are due to meiotic I nondisjunction events. In contrast, more paternal UPD(15) cases so far examined appear to have a postzygotic origin of the extra paternal chromosome. 33 refs., 1 fig., 7 tabs.

  20. Consequences of recombination on traditional phylogenetic analysis

    DEFF Research Database (Denmark)

    Schierup, M H; Hein, J

    2000-01-01

    We investigate the shape of a phylogenetic tree reconstructed from sequences evolving under the coalescent with recombination. The motivation is that evolutionary inferences are often made from phylogenetic trees reconstructed from population data even though recombination may well occur (mt......DNA or viral sequences) or does occur (nuclear sequences). We investigate the size and direction of biases when a single tree is reconstructed ignoring recombination. Standard software (PHYLIP) was used to construct the best phylogenetic tree from sequences simulated under the coalescent with recombination....... With recombination present, the length of terminal branches and the total branch length are larger, and the time to the most recent common ancestor smaller, than for a tree reconstructed from sequences evolving with no recombination. The effects are pronounced even for small levels of recombination that may...

  1. NOD mouse model for Sjögren's syndrome: lack of longitudinal stability

    NARCIS (Netherlands)

    Lodde, B. M.; Mineshiba, F.; Kok, M. R.; Wang, J.; Zheng, C.; Schmidt, M.; Cotrim, A. P.; Kriete, M.; Tak, P. P.; Baum, B. J.

    2006-01-01

    OBJECTIVES: The non-obese diabetic (NOD) mouse is not only a widely used model for diabetes mellitus type I, but also for the chronic autoimmune disease Sjögren's syndrome (SS), mainly affecting salivary and lacrimal glands. We studied the efficacy of local recombinant serotype 2 adeno-associated

  2. Mouse Genome Informatics (MGI)

    Data.gov (United States)

    U.S. Department of Health & Human Services — MGI is the international database resource for the laboratory mouse, providing integrated genetic, genomic, and biological data to facilitate the study of human...

  3. Mouse Phenome Database (MPD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Mouse Phenome Database (MPD) has characterizations of hundreds of strains of laboratory mice to facilitate translational discoveries and to assist in selection...

  4. Local Chromatin Features Including PU.1 and IKAROS Binding and H3K4 Methylation Shape the Repertoire of Immunoglobulin Kappa Genes Chosen for V(DJ Recombination

    Directory of Open Access Journals (Sweden)

    Louise S. Matheson

    2017-11-01

    Full Text Available V(DJ recombination is essential for the generation of diverse antigen receptor (AgR repertoires. In B cells, immunoglobulin kappa (Igκ light chain recombination follows immunoglobulin heavy chain (Igh recombination. We recently developed the DNA-based VDJ-seq assay for the unbiased quantitation of Igh VH and DH repertoires. Integration of VDJ-seq data with genome-wide datasets revealed that two chromatin states at the recombination signal sequence (RSS of VH genes are highly predictive of recombination in mouse pro-B cells. It is unknown whether local chromatin states contribute to Vκ gene choice during Igκ recombination. Here we adapt VDJ-seq to profile the Igκ VκJκ repertoire and present a comprehensive readout in mouse pre-B cells, revealing highly variable Vκ gene usage. Integration with genome-wide datasets for histone modifications, DNase hypersensitivity, transcription factor binding and germline transcription identified PU.1 binding at the RSS, which was unimportant for Igh, as highly predictive of whether a Vκ gene will recombine or not, suggesting that it plays a binary, all-or-nothing role, priming genes for recombination. Thereafter, the frequency with which these genes recombine was shaped both by the presence and level of enrichment of several other chromatin features, including H3K4 methylation and IKAROS binding. Moreover, in contrast to the Igh locus, the chromatin landscape of the promoter, as well as of the RSS, contributes to Vκ gene recombination. Thus, multiple facets of local chromatin features explain much of the variation in Vκ gene usage. Together, these findings reveal shared and divergent roles for epigenetic features and transcription factors in AgR V(DJ recombination and provide avenues for further investigation of chromatin signatures that may underpin V(DJ-mediated chromosomal translocations.

  5. CRMAGE: CRISPR Optimized MAGE Recombineering

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten Otto Alexander

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and λ Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli...... that are assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the λ Red...

  6. Determination of recombination in Mycoplasma hominis

    DEFF Research Database (Denmark)

    Jacobsen, Iben Søgaard; Boesen, Thomas; Mygind, Tina

    2002-01-01

    indicating the presence of recombination. In order to test for intergenic recombination, phylogenetic trees were reconstructed for each of the genes but no well-supported bifurcating phylogenetic trees could be obtained. The genes were tested for intragenic recombination using the correlation between linkage...... disequilibrium and distance between the segregating sites, by the homoplasy ratio (H ratio), and by compatibility matrices. The gap gene showed well-supported evidence for high levels of recombination, whereas recombination was less frequent and not significant within the other genes. The analysis revealed...... intergenic and intragenic recombination in M. hominis and this may explain the high intraspecies variability. The results obtained in the present study may be of importance for future population studies of Mycoplasma species....

  7. Recombination patterns in maize reveal limits to crossover homeostasis.

    Science.gov (United States)

    Sidhu, Gaganpreet K; Fang, Celestia; Olson, Mischa A; Falque, Matthieu; Martin, Olivier C; Pawlowski, Wojciech P

    2015-12-29

    During meiotic recombination, double-strand breaks (DSBs) are formed in chromosomal DNA and then repaired as either crossovers (COs) or non-crossovers (NCOs). In most taxa, the number of DSBs vastly exceeds the number of COs. COs are required for generating genetic diversity in the progeny, as well as proper chromosome segregation. Their formation is tightly controlled so that there is at least one CO per pair of homologous chromosomes whereas the maximum number of COs per chromosome pair is fairly limited. One of the main mechanisms controlling the number of recombination events per meiosis is CO homeostasis, which maintains a stable CO number even when the DSB number is dramatically altered. The existence of CO homeostasis has been reported in several species, including mouse, yeast, and Caenorhabditis elegans. However, it is not known whether homeostasis exists in the same form in all species. In addition, the studies of homeostasis have been conducted using mutants and/or transgenic lines exhibiting fairly severe meiotic phenotypes, and it is unclear how important homeostasis is under normal physiological conditions. We found that, in maize, CO control is robust only to ensure one CO per chromosome pair. However, once this limit is reached, the CO number is linearly related to the DSB number. We propose that CO control is a multifaceted process whose different aspects have a varying degree of importance in different species.

  8. Divide and Recombine for Large Complex Data

    Science.gov (United States)

    2017-12-01

    SUPPLEMENTARY NOTES 14. ABSTRACT Divide and Recombine (D& R ) statistical approach was developed for analyzing ‘big data’ where the computational complexity...is very high. The analyst divides data into subsets by a D& R division technique, applying analytic methods to each subset independently, without...communication. Outputs of each analytic method are recombined by a D& R recombination procedure, which allows extensive parallel computation. DeltaRho

  9. Gene Mapping with Recombinant Inbreds in Maize

    OpenAIRE

    Burr, B; Burr, F A; Thompson, K. H.; Albertson, M. C.; Stuber, C. W.

    1988-01-01

    Recombinant inbred lines of maize have been developed for the rapid mapping of molecular probes to chromosomal location. Two recombinant inbred families have been constructed from F(2) populations of T232 X CM37 and CO159 X Tx303. A genetic map based largely on isozymes and restriction fragment length polymorphisms has been produced that covers virtually the entire maize genome. In order to map a new gene, an investigator has only to determine its allelic distribution among the recombinant in...

  10. Rapid purification of recombinant histones.

    Directory of Open Access Journals (Sweden)

    Henrike Klinker

    Full Text Available The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  11. Toxicological evaluation of lactase derived from recombinant Pichia pastoris.

    Directory of Open Access Journals (Sweden)

    Shiying Zou

    Full Text Available A recombinant lactase was expressed in Pichia pastoris, resulting in enzymatic activity of 3600 U/mL in a 5 L fermenter. The lactase product was subjected to a series of toxicological tests to determine its safety for use as an enzyme preparation in the dairy industry. This recombinant lactase had the highest activity of all recombinant strains reported thus far. Acute oral toxicity, mutagenicity, genotoxic, and subchronic toxicity tests performed in rats and mice showed no death in any groups. The lethal dose 50% (LD50 based on the acute oral toxicity study is greater than 30 mL/kg body weight, which is in accordance with the 1500 L milk consumption of a 50 kg human daily. The lactase showed no mutagenic activity in the Ames test or a mouse sperm abnormality test at levels of up to 5 mg/plate and 1250 mg/kg body weight, respectively. It also showed no genetic toxicology in a bone marrow cell micronucleus test at levels of up to 1250 mg/kg body weight. A 90-day subchronic repeated toxicity study via the diet with lactase levels up to 1646 mg/kg (1000-fold greater than the mean human exposure did not show any treatment-related significant toxicological effects on body weight, food consumption, organ weights, hematological and clinical chemistry, or histopathology compared to the control groups. This toxicological evaluation system is comprehensive and can be used in the safety evaluation of other enzyme preparations. The lactase showed no acute, mutagenic, genetic, or subchronic toxicity under our evaluation system.

  12. The Red Queen theory of recombination hotspots.

    Science.gov (United States)

    Ubeda, F; Wilkins, J F

    2011-03-01

    Recombination hotspots are small chromosomal regions, where meiotic crossover events happen with high frequency. Recombination is initiated by a double-strand break (DSB) that requires the intervention of the molecular repair mechanism. The DSB repair mechanism may result in the exchange of homologous chromosomes (crossover) and the conversion of the allelic sequence that breaks into the one that does not break (biased gene conversion). Biased gene conversion results in a transmission advantage for the allele that does not break, thus preventing recombination and rendering recombination hotspots transient. How is it possible that recombination hotspots persist over evolutionary time (maintaining the average chromosomal crossover rate) when they are self-destructive? This fundamental question is known as the recombination hotspot paradox and has attracted much attention in recent years. Yet, that attention has not translated into a fully satisfactory answer. No existing model adequately explains all aspects of the recombination hotspot paradox. Here, we formulate an intragenomic conflict model resulting in Red Queen dynamics that fully accounts for all empirical observations regarding the molecular mechanisms of recombination hotspots, the nonrandom targeting of the recombination machinery to hotspots and the evolutionary dynamics of hotspot turnover. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

  13. Epitope tagging of recombinant proteins.

    Science.gov (United States)

    Brizzard, B; Chubet, R

    2001-05-01

    Epitope tagging is a method of expressing proteins whereby an epitope for a specific monoclonal antibody is fused to a target protein using recombinant DNA techniques. The fusion gene is cloned into an appropriate expression vector for the experimental cell type and host cells are transfected. The fusion protein can then be detected and/or purified using a monoclonal antibody specific for the epitope tag. This unit presents protocols for detection and purification of proteins tagged with a particular epitope, the FLAG tag, although the same general approach can be applied to other epitope tags. The protocols in this unit employ the anti-FLAG M2 antibody to detect and purify FLAG-tagged proteins. The methods presented are immunoprecipitation of FLAG fusion proteins from cells using an anti-FLAG M2 affinity gel, detection of FLAG fusion proteins by western blotting, and purification of FLAG fusion proteins by anti-FLAG M2 affinity chromatography.

  14. Fundamental Studies of Recombinant Hydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. [Univ. of Georgia, Athens, GA (United States)

    2014-01-25

    This research addressed the long term goals of understanding the assembly and organization of hydrogenase enzymes, of reducing them in size and complexity, of determining structure/function relationships, including energy conservation via charge separation across membranes, and in screening for novel H2 catalysts. A key overall goal of the proposed research was to define and characterize minimal hydrogenases that are produced in high yields and are oxygen-resistant. Remarkably, in spite of decades of research carried out on hydrogenases, it is not possible to readily manipulate or design the enzyme using molecular biology approaches since a recombinant form produced in a suitable host is not available. Such resources are essential if we are to understand what constitutes a “minimal” hydrogenase and design such catalysts with certain properties, such as resistance to oxygen, extreme stability and specificity for a given electron donor. The model system for our studies is Pyrococcus furiosus, a hyperthermophile that grows optimally at 100°C, which contains three different nickel-iron [NiFe-] containing hydrogenases. Hydrogenases I and II are cytoplasmic while the other, MBH, is an integral membrane protein that functions to both evolve H2 and pump protons. Three important breakthroughs were made during the funding period with P. furiosus soluble hydrogenase I (SHI). First, we produced an active recombinant form of SHI in E. coli by the co-expression of sixteen genes using anaerobically-induced promoters. Second, we genetically-engineered P. furiosus to overexpress SHI by an order of magnitude compared to the wild type strain. Third, we generated the first ‘minimal’ form of SHI, one that contained two rather than four subunits. This dimeric form was stable and active, and directly interacted with a pyruvate-oxidizing enzyme with any intermediate electron carrier. The research resulted in five peer-reviewed publications.

  15. Differential Susceptibility to Hepatic Inflammation and Proliferation in AXB Recombinant Inbred Mice Chronically Infected with Helicobacter hepaticus

    OpenAIRE

    Ihrig, Melanie; Schrenzel, Mark D.; Fox, James G.

    1999-01-01

    Helicobacter hepaticus is a naturally occurring pathogen of mice and has been used to develop models of chronic hepatitis, liver cancer, and, more recently, inflammatory bowel disease, in selected mouse strains. A/JCr mice are particularly susceptible to H. hepaticus-induced hepatitis and subsequent development of liver neoplasms, whereas C57BL/6 mice are resistant. In this study, we inoculated nine AXB recombinant inbred (RI) mouse strains, derived from A/J and C57BL/6 mice, with H. hepaticu...

  16. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  17. Recombinant Poliovirus circulation among healthy children ...

    African Journals Online (AJOL)

    Recombinant Poliovirus circulation among healthy children immunized with oral polio vaccine in Abidjan. ... African Journal of Biotechnology ... In order to assess the level of polio virus with natural recombinant genome and wild polio virus circulating in the environment of healthy children aged 0 to 5 years in Abidjan, 130 ...

  18. Expression and characterization of recombinant human serum ...

    African Journals Online (AJOL)

    It was specifically recognized by the anti-human HSA antibody and CP antibody in Western blotting assay. In vitro, the recombinant HSA-CP can stimulate HEK293 cell proliferation. In Zucker diabetic fatty (ZDF) rats, 12 weeks recombinant HSA-CP treatment could prevent the accumulation of glomerular extracellular matrix, ...

  19. Colonization, mouse-style

    Directory of Open Access Journals (Sweden)

    Searle Jeremy B

    2010-10-01

    Full Text Available Abstract Several recent papers, including one in BMC Evolutionary Biology, examine the colonization history of house mice. As well as background for the analysis of mouse adaptation, such studies offer a perspective on the history of movements of the humans that accidentally transported the mice. See research article: http://www.biomedcentral.com/1471-2148/10/325

  20. Characterization of Bovine 5′-flanking Region during Differentiation of Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Hye-Jeong Jang

    2015-12-01

    Full Text Available Embryonic stem cells (ESCs have been used as a powerful tool for research including gene manipulated animal models and the study of developmental gene regulation. Among the critical regulatory factors that maintain the pluripotency and self-renewal of undifferentiated ESCs, NANOG plays a very important role. Nevertheless, because pluripotency maintaining factors and specific markers for livestock ESCs have not yet been probed, few studies of the NANOG gene from domestic animals including bovine have been reported. Therefore, we chose mouse ESCs in order to understand and compare NANOG expression between bovine, human, and mouse during ESCs differentiation. We cloned a 600 bp (−420/+181 bovine NANOG 5′-flanking region, and tagged it with humanized recombinant green fluorescent protein (hrGFP as a tracing reporter. Very high GFP expression for bovine NANOG promoter was observed in the mouse ESC line. GFP expression was monitored upon ESC differentiation and was gradually reduced along with differentiation toward neurons and adipocyte cells. Activity of bovine NANOG (−420/+181 promoter was compared with already known mouse and human NANOG promoters in mouse ESC and they were likely to show a similar pattern of regulation. In conclusion, bovine NANOG 5-flanking region functions in mouse ES cells and has characteristics similar to those of mouse and human. These results suggest that bovine gene function studied in mouse ES cells should be evaluated and extrapolated for application to characterization of bovine ES cells.

  1. Treatment with recombinant interferon-beta reduces inflammation and slows cartilage destruction in the collagen-induced arthritis model of rheumatoid arthritis

    NARCIS (Netherlands)

    van Holten, Judith; Reedquist, Kris; Sattonet-Roche, Pascale; Smeets, Tom J. M.; Plater-Zyberk, Christine; Vervoordeldonk, Margriet J.; Tak, Paul P.

    2004-01-01

    We investigated the therapeutic potential and mechanism of action of IFN-beta protein for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis was induced in DBA/1 mice. At the first clinical sign of disease, mice were given daily injections of recombinant mouse IFN-beta or saline

  2. Production and characterization of monoclonal antibodies raised against recombinant human granzymes A and B and showing cross reactions with the natural proteins

    NARCIS (Netherlands)

    Kummer, J. Alain; Kamp, Angela M.; van Katwijk, Marcel; Brakenhoff, Just P.J.; Radosevic, Katarina; Radosevic, K.; van Leeuwen, Anne Marie; Borst, Jannie; Verweij, Cornelis L.; Hack, C. Erik

    1993-01-01

    The human serine proteases granzymes A and B are expressed in cytotoplasmic granules of activated cytotoxic T lymphocytes and natural killer cells. Recombinant granzyme A and granzyme B proteins were produced in bacteria, purified and then used to raise specific mouse monoclonal antibodies. Seven

  3. The function of platelet-derived growth factor in the differentiation of mouse tongue striated muscle.

    Science.gov (United States)

    Suzuki, E; Aoyama, K; Fukui, T; Nakamura, Y; Yamane, A

    2012-02-01

    To determine the function of platelet-derived growth factor (PDGF) in the final differentiation phase of tongue striated muscle cells. We analyzed the expressions of PDGF-A, -B, platelet-derived growth factor receptor (PDGFR)-α, and PDGFR-β in mouse tongues between embryonic days (E) 11 and 15. Furthermore, we examined the effects of human recombinant PDGF-AB and the peptide antagonist for PDGFRs using an organ culture system of mouse embryonic tongue. Mouse tongues at E12 were cultured in BGJb medium containing human recombinant PDGF-AB for 4 days or the peptide antagonist for PDGF receptors for 8 days. PDGF-A, -B, PDGFR-α, and -β were expressed in the differentiating muscle cells between E11 and 15. The human recombinant PDGF-AB induced increases in the mRNA expressions of myogenin and muscle creatine kinase (MCK) and the number of fast myosin heavy chain (fMHC)-positive cells, markers for the differentiation of muscle cells. On the other hand, the peptide antagonist for PDGFRs induced suppressions in the mRNA expressions of myogenin and MCK, and the number of fMHC-positive cells. Both the PDGF-AB and the antagonist failed to affect the expressions of cell proliferation markers. These results suggest that PDGF functions as a positive regulator in the final differentiation phase of tongue muscle cells in mouse embryos. © 2012 John Wiley & Sons A/S.

  4. Occupational mouse allergen exposure among non-mouse handlers.

    Science.gov (United States)

    Curtin-Brosnan, Jean; Paigen, Beverly; Hagberg, Karol A; Langley, Stephen; O'Neil, Elise A; Krevans, Mary; Eggleston, Peyton A; Matsui, Elizabeth C

    2010-12-01

    This study assessed mouse allergen exposure across a range of jobs, including non-mouse handling jobs, at a mouse facility. Baseline data from 220 new employees enrolled in the Jackson Laboratory (JAXCohort) were analyzed. The baseline assessment included a questionnaire, allergy skin testing, and spirometry. Exposure assessments consisted of collection of two full-shift breathing zone air samples during a 1-week period. Air samples were analyzed for mouse allergen content, and the mean concentration of the two shifts represented mouse allergen exposure for that employee. The mean age of the 220 participants was 33 years. Ten percent reported current asthma and 56% were atopic. Thirty-eight percent were animal caretakers, 20% scientists, 20% administrative/support personnel, 10% materials/supplies handlers, and 9% laboratory technicians. Sixty percent of the population handled mice. Eighty-two percent of study participants had detectable breathing zone mouse allergen, and breathing zone mouse allergen concentrations were 1.02 ng/m³ (0.13-6.91) (median [interquartile range (IQR)]. Although mouse handlers had significantly higher concentrations of breathing zone mouse allergen than non-handlers (median [IQR]: 4.13 ng/m³ [0.69-12.12] and 0.21 ng/m³ [below detection (BD)-0.63], respectively; p < 0.001), 66% of non-handlers had detectable breathing zone mouse allergen. Mouse allergen concentrations among administrative/support personnel and materials/supplies handlers, jobs that generally do not entail handling mice, were median [IQR]: 0.23 ng/m³ [BD-0.59] and 0.63 ng/m³ [BD-18.91], respectively. Seventy-one percent of administrative/support personnel, and 68% of materials/supplies handlers had detectable breathing zone mouse allergen. As many as half of non-mouse handlers may have levels of exposure that are similar to levels observed among mouse handlers.

  5. Detection of Mouse Mammary Tumour Virus in house mice

    DEFF Research Database (Denmark)

    Steffensen, Lise K; Leirs, Herwig; Heiberg, Ann-Charlotte

    The prevalence of human breast cancer (HBC) is affected by several parameters. For the past decades MMTV, Mouse Mammary Tumor Virus, known to cause breast cancer in mice, has been hypothesized to affect the frequency of hormone dependent HBC. Though conclusive evidence has not been produced, still...... and the fact that human cells can be infected in vitro strengthen the theory. Results from above mentioned studies indicate that the source of provirus is exogenous. The transmission mechanism is tentatively suggested to be by means of recombination of exogeneous and endogenous viruses obtained from...

  6. Reciprocality of Recombination Events That Rearrange the Chromosome

    OpenAIRE

    Mahan, M. J.; Roth, J. R.

    1988-01-01

    We describe a genetic system for studying the reciprocality of chromosomal recombination; all substrates and recombination functions involved are provided exclusively by the bacterial chromosome. The genetic system allows the recovery of both recombinant products from a single recombination event. The system was used to demonstrate the full reciprocality of three different types of recombination events: (1) intrachromosomal recombination between direct repeats, causing deletions; (2) intrachr...

  7. Recombination activating gene-2null severe combined immunodeficient pigs and mice engraft human induced pluripotent stem cells differently

    OpenAIRE

    Choi, Yun-Jung; Kim, Eunsu; Reza, Abu Musa Md Talimur; Hong, Kwonho; Song, Hyuk; Park, Chankyu; Cho, Seong-Keun; Lee, Kiho; Prather, Randall S.; Kim, Jin-Hoi

    2017-01-01

    This study comparatively investigated the transcriptional, physiological, and phenotypic differences of the immune disorder between severe combined immunodeficient (SCID) mouse and pig models. We discovered that the recombination activating gene-2 (Rag-2) SCID mice, but not RAG-2 SCID pigs, showed intense, infrequent, and mild cluster of CD3+-, CD4+-, and CD8+ signals respectively, suggesting that distinct species-specific effects exist. Furthermore, the expression of six relevant genes (NFAT...

  8. Inheritance of Mating Fators in Nocardial Recombinants

    Science.gov (United States)

    Brownell, George H.; Kelly, Karol L.

    1969-01-01

    The segregation of mating loci with other unselected genes was analyzed in recombinants obtained from matings of Nocardia canicruria and N. erythropolis. The loci C/c and E/e control nocardial compatibility. Four mating genotype combinations were observed: cE, Ce, CE, and ce. Strains of N. erythropolis bear the genotype cE and strains of N. canicruria bear the Ce alleles. The CE recombinant mating type is capable of mating with both organisms, whereas the ce-containing recombinant is nonfertile. The E locus was found to segregate with StrA1 (streptomycin-resistance gene) on the N. erythropolis linkage group. The C locus appeared linked to PurB2 (purine-requiring gene) on the N. canicruria linkage group. A few observed recombinants were capable of further segregation of unselected characters after colonial purification, suggesting a possible heterogenomic condition or multiple rounds of mating. Prior treatment of recombinants with acriflavine failed to alter their compatibility or the frequency at which recombinants were recovered. The segregation pattern of the mating loci allowed for specific recombinant class types to be compatible. PMID:5802610

  9. Inheritance of mating factors in nocardial recombinants.

    Science.gov (United States)

    Brownell, G H; Kelly, K L

    1969-07-01

    The segregation of mating loci with other unselected genes was analyzed in recombinants obtained from matings of Nocardia canicruria and N. erythropolis. The loci C/c and E/e control nocardial compatibility. Four mating genotype combinations were observed: cE, Ce, CE, and ce. Strains of N. erythropolis bear the genotype cE and strains of N. canicruria bear the Ce alleles. The CE recombinant mating type is capable of mating with both organisms, whereas the ce-containing recombinant is nonfertile. The E locus was found to segregate with StrA1 (streptomycin-resistance gene) on the N. erythropolis linkage group. The C locus appeared linked to PurB2 (purine-requiring gene) on the N. canicruria linkage group. A few observed recombinants were capable of further segregation of unselected characters after colonial purification, suggesting a possible heterogenomic condition or multiple rounds of mating. Prior treatment of recombinants with acriflavine failed to alter their compatibility or the frequency at which recombinants were recovered. The segregation pattern of the mating loci allowed for specific recombinant class types to be compatible.

  10. Initiation of meiotic recombination in Ustilago maydis.

    Science.gov (United States)

    Kojic, Milorad; Sutherland, Jeanette H; Pérez-Martín, José; Holloman, William K

    2013-12-01

    A central feature of meiosis is the pairing and recombination of homologous chromosomes. Ustilago maydis, a biotrophic fungus that parasitizes maize, has long been utilized as an experimental system for studying recombination, but it has not been clear when in the life cycle meiotic recombination initiates. U. maydis forms dormant diploid teliospores as the end product of the infection process. Upon germination, teliospores complete meiosis to produce four haploid basidiospores. Here we asked whether the meiotic process begins when teliospores germinate or at an earlier stage in development. When teliospores homozygous for a cdc45 mutation temperature sensitive for DNA synthesis were germinated at the restrictive temperature, four nuclei became visible. This implies that teliospores have already undergone premeiotic DNA synthesis and suggests that meiotic recombination initiates at a stage of infection before teliospores mature. Determination of homologous recombination in plant tissue infected with U. maydis strains heteroallelic for the nar1 gene revealed that Nar(+) recombinants were produced at a stage before teliospore maturation. Teliospores obtained from a spo11Δ cross were still able to germinate but the process was highly disturbed and the meiotic products were imbalanced in chromosomal complement. These results show that in U. maydis, homologous recombination initiates during the infection process and that meiosis can proceed even in the absence of Spo11, but with loss of genomic integrity.

  11. First-principles study of Frenkel pair recombination in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Shi-Yao; Jin, Shuo, E-mail: jinshuo@buaa.edu.cn; Li, Yu-Hao; Zhou, Hong-Bo; Zhang, Ying; Lu, Guang-Hong

    2017-02-15

    The recombination of one Frenkel pair in tungsten has been investigated through first-principles simulation. Two different recombination types have been identified: instantaneous and thermally activated. The small recombination barriers for thermally activated recombination cases indicate that recombination can occur easily with a slightly increased temperature. For both of the two recombination types, recombination occurs through the self-interstitial atom moving towards the vacancy. The recombination process can be direct or through replacement sequences, depending on the vertical distance between the vacancy and the 〈1 1 1〉 line of self-interstitial atom pair.

  12. First-principles study of Frenkel pair recombination in tungsten

    Science.gov (United States)

    Qin, Shi-Yao; Jin, Shuo; Li, Yu-Hao; Zhou, Hong-Bo; Zhang, Ying; Lu, Guang-Hong

    2017-02-01

    The recombination of one Frenkel pair in tungsten has been investigated through first-principles simulation. Two different recombination types have been identified: instantaneous and thermally activated. The small recombination barriers for thermally activated recombination cases indicate that recombination can occur easily with a slightly increased temperature. For both of the two recombination types, recombination occurs through the self-interstitial atom moving towards the vacancy. The recombination process can be direct or through replacement sequences, depending on the vertical distance between the vacancy and the line of self-interstitial atom pair.

  13. Production of recombinant proteins by filamentous fungi.

    Science.gov (United States)

    Ward, Owen P

    2012-01-01

    The initial focus of recombinant protein production by filamentous fungi related to exploiting the extraordinary extracellular enzyme synthesis and secretion machinery of industrial strains, including Aspergillus, Trichoderma, Penicillium and Rhizopus species, was to produce single recombinant protein products. An early recognized disadvantage of filamentous fungi as hosts of recombinant proteins was their common ability to produce homologous proteases which could degrade the heterologous protein product and strategies to prevent proteolysis have met with some limited success. It was also recognized that the protein glycosylation patterns in filamentous fungi and in mammals were quite different, such that filamentous fungi are likely not to be the most suitable microbial hosts for production of recombinant human glycoproteins for therapeutic use. By combining the experience gained from production of single recombinant proteins with new scientific information being generated through genomics and proteomics research, biotechnologists are now poised to extend the biomanufacturing capabilities of recombinant filamentous fungi by enabling them to express genes encoding multiple proteins, including, for example, new biosynthetic pathways for production of new primary or secondary metabolites. It is recognized that filamentous fungi, most species of which have not yet been isolated, represent an enormously diverse source of novel biosynthetic pathways, and that the natural fungal host harboring a valuable biosynthesis pathway may often not be the most suitable organism for biomanufacture purposes. Hence it is expected that substantial effort will be directed to transforming other fungal hosts, non-fungal microbial hosts and indeed non microbial hosts to express some of these novel biosynthetic pathways. But future applications of recombinant expression of proteins will not be confined to biomanufacturing. Opportunities to exploit recombinant technology to unravel the

  14. Recombinant vaccines against bluetongue virus.

    Science.gov (United States)

    Calvo-Pinilla, Eva; Castillo-Olivares, Javier; Jabbar, Tamara; Ortego, Javier; de la Poza, Francisco; Marín-López, Alejandro

    2014-03-01

    Bluetongue (BT) is a hemorrhagic disease of ruminants caused by bluetongue virus (BTV), the prototype member of the genus Orbivirus within the family Reoviridae and is transmitted via biting midges of the genus Culicoides. BTV can be found on all continents except Antarctica, and up to 26 immunologically distinct BTV serotypes have been identified. Live attenuated and inactivated BTV vaccines have been used over the years with different degrees of success. The multiple outbreaks of BTV in Mediterranean Europe in the last two decades and the incursion of BTV-8 in Northern Europe in 2008 has re-stimulated the interest to develop improved vaccination strategies against BTV. In particular, safer, cross-reactive, more efficacious vaccines with differential diagnostic capability have been pursued by multiple BTV research groups and vaccine manufacturers. A wide variety of recombinant BTV vaccine prototypes have been investigated, ranging from baculovirus-expressed sub-unit vaccines to the use of live viral vectors. This article gives a brief overview of all these modern approaches to develop vaccines against BTV including some recent unpublished data. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Combination keyboard and mouse

    OpenAIRE

    Cigale, Matej

    2010-01-01

    The object of this thesis is design and construction of a device that can replace a standard keyboard and mouse. The history of the standard keyboard is presented and the most known alternative the Dvorak Simplified Keyboard is described. The basic principals that August Dvorak used in designing his keyboard are also used in our design. In other to achieve this the knowledge of the characteristics of Slovenian language are required. The characteristics that we require to design our keyboar...

  16. Hybrid Sterility, Mouse

    OpenAIRE

    Forejt, J

    2013-01-01

    The review summarizes hybrid sterility as the best studied example of reproductive isolation between closely related species. On the model of infertile hybrids of two domestic mouse subspecies, Mus musculus musculus and Mus musculus domesticus, we have demonstrated interaction of hybrid sterility genes with epigenetic control of transcriptional inactivation of the X and Y sex chromosomes. This leads to the activation of pachytene checkpoint and finally results in the arrest of spermatogenesis.

  17. The Red Queen model of recombination hot-spot evolution: a theoretical investigation.

    Science.gov (United States)

    Latrille, Thibault; Duret, Laurent; Lartillot, Nicolas

    2017-12-19

    In humans and many other species, recombination events cluster in narrow and short-lived hot spots distributed across the genome, whose location is determined by the Zn-finger protein PRDM9. To explain these fast evolutionary dynamics, an intra-genomic Red Queen model has been proposed, based on the interplay between two antagonistic forces: biased gene conversion, mediated by double-strand breaks, resulting in hot-spot extinction, followed by positive selection favouring new PRDM9 alleles recognizing new sequence motifs. Thus far, however, this Red Queen model has not been formalized as a quantitative population-genetic model, fully accounting for the intricate interplay between biased gene conversion, mutation, selection, demography and genetic diversity at the PRDM9 locus. Here, we explore the population genetics of the Red Queen model of recombination. A Wright-Fisher simulator was implemented, allowing exploration of the behaviour of the model (mean equilibrium recombination rate, diversity at the PRDM9 locus or turnover rate) as a function of the parameters (effective population size, mutation and erosion rates). In a second step, analytical results based on self-consistent mean-field approximations were derived, reproducing the scaling relations observed in the simulations. Empirical fit of the model to current data from the mouse suggests both a high mutation rate at PRDM9 and strong biased gene conversion on its targets.This article is part of the themed issue 'Evolutionary causes and consequences of recombination rate variation in sexual organisms'. © 2017 The Authors.

  18. Beyond the 12/23 rule of VDJ recombination independent of the Rag proteins.

    Science.gov (United States)

    Olaru, Alexandru; Petrie, Howard T; Livák, Ferenc

    2005-05-15

    The combinatorial repertoire of AgRs is established through somatic recombination of V, D, and J gene segments during lymphocyte development. Incorporation of D segments into IgH, TCRbeta, and TCRdelta chains also contributes to junctional diversification by substantially extending the length of the third CDR. The V, D, and J gene segments are flanked by recombination signals (RS) of 12- or 23-mer spacer length that direct recombination according to the 12/23 rule. D genes in the TCRbeta and TCRdelta loci are flanked by a 12RS and 23RS, and their incorporation is controlled by mechanisms "beyond the 12/23 rule." In the TCRbeta locus, selective interactions between Rag proteins and the RS flanking the V-D and D-J genes, respectively, are sufficient to enforce D gene usage. In this article, we report that in the TCRdelta locus, the Rag proteins are not the major determinant of D gene incorporation. In developing mouse and human thymocytes, the two Ddelta genes rearrange predominantly to form D-D coding joints. In contrast, when tested in ex vivo transfection assays in a nonlymphoid cell line, the flanking RS mediate deletion, rather than incorporation, of the two D genes on both exogenous recombination substrates and the endogenous locus. These results suggest that selective Rag-RS interactions are not the sole regulators of D gene segment incorporation, and additional, perhaps lymphocyte-specific, mechanisms exist that allow proper shaping of the primary AgR repertoire.

  19. FBH1 helicase disrupts RAD51 filaments in vitro and modulates homologous recombination in mammalian cells

    DEFF Research Database (Denmark)

    Simandlova, Jitka; Zagelbaum, Jennifer; Payne, Miranda J

    2013-01-01

    Efficient repair of DNA double strand breaks and interstrand cross-links requires the homologous recombination (HR) pathway, a potentially error-free process that utilizes a homologous sequence as a repair template. A key player in HR is RAD51, the eukaryotic ortholog of bacterial RecA protein. RAD....... Using a combination of molecular genetic, biochemical, and single-molecule biophysical techniques, we provide mechanistic insight into the mode of action of the FBH1 helicase as a regulator of RAD51-dependent HR in mammalian cells. We show that FBH1 binds directly to RAD51 and is able to disrupt RAD51...... filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under...

  20. Toxicity tests on native and recombinant Bordetella pertussis adenylate cyclase toxin preparations.

    Science.gov (United States)

    Hormozi, K; Parton, R; Coote, J

    1999-01-01

    Bordetella pertussis produces a cell-invasive adenylate cyclase toxin which is synthesised from the cyaA gene as an inactive protoxin that is post-translationally activated by the product of the cyaC gene. Active and inactive CyaA proteins were prepared in crude and purified form from B. pertussis or from recombinant E. coli expressing both cyaA and cyaC genes or the cyaA gene alone, respectively. The specific AC activities of all the crude or all the purified toxins were similar. The toxins produced in the absence of CyaC activity had no cell invasive, haemolytic or cytotoxic activity. The cell invasive and cytotoxic activities of native and recombinant active CyaA preparations were similar, but the haemolytic activity of the recombinant toxin was lower than that of the native protein. As part of mouse protection tests, mice were injected subcutaneously with 15 microg per mouse of crude or purified CyaA preparations plus alhydrogel or with 1/5 human dose of adsorbed DPT vaccine (Wellcome Trivax-AD) using two doses at a two week interval. Control groups of mice were injected with alhydrogel in PBS alone or left unvaccinated. The toxin preparations had little or no effect on mouse weight gain, and there were no marked differences between mice vaccinated with the active toxin and those given the inactive form. Thus, at the dose used, there was no clear toxic physiological response caused specifically by active CyaA.

  1. Fourteen genetically variant proteins of mouse brain: discovery of two new variants and chromosomal mapping of four loci.

    Science.gov (United States)

    Goldman, D; Pikus, H J

    1986-04-01

    With the description here of variant proteins A13 (pI 5.9, MW 62 kd) and A14 (pI 5.3, MW 26 kd), 14 polypeptides of mouse brain visualized by two-dimensional electrophoresis (2DE) exhibit genetic variation in isoelectric point. Using 22 B X D recombinant inbred strains, we map four of these loci and show that a fifth is independent of known loci. A pI 5.6, 81-kd protein of mouse brain mitochondria designated A1 is demonstrated to be an independent locus closely linked to LY-2 and LVP-1 on mouse chromosome 6. A pI 5.6, 28-kd genetically variant brain polypeptide designated A12 maps to chromosome 1 and shows identity with the known mouse locus LTW-4. The locus for A8 is not closely linked to any previously mapped locus. However, the locus for the newly described variant A13 shows 3 of 18 recombinants with the DNA polymorphism RN7S-2 and 2 of 18 recombinants with HC (hemolytic complement) and is thus probably located proximally to HC near the centromere of chromosome 2. Genetic and biochemical evidence is presented for the identification of A14 as ALP-1 (apolipoprotein 1), mapping to chromosome 9. In addition to these 13 genetically variant polypeptides, the positions of 12 other polypeptides which have been identified on 2DE gels of mouse brain are given.

  2. Ultramicroscopic observation of recombinant adenoassociated virus ...

    African Journals Online (AJOL)

    Ultramicroscopic observation of recombinant adenoassociated virus type 2 on the surface of formvarcarbon coated copper grids under different relative humidity and incubation time using negative stain transmission electron microscopy.

  3. Recombinant Human Papillomavirus (HPV) Nonavalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) nonavalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  4. Recombinant Human Papillomavirus (HPV) Quadrivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) quadrivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  5. Recombinant Human Papillomavirus (HPV) Bivalent Vaccine

    Science.gov (United States)

    This page contains brief information about recombinant human papillomavirus (HPV) bivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  6. Invariant Measures of Genetic Recombination Processes

    Science.gov (United States)

    Akopyan, Arseniy V.; Pirogov, Sergey A.; Rybko, Aleksandr N.

    2015-07-01

    We construct a non-linear Markov process connected with a biological model of a bacterial genome recombination. The description of invariant measures of this process gives us the solution of one problem in elementary probability theory.

  7. RNAi and heterochromatin repress centromeric meiotic recombination

    DEFF Research Database (Denmark)

    Ellermeier, Chad; Higuchi, Emily C; Phadnis, Naina

    2010-01-01

    During meiosis, the formation of viable haploid gametes from diploid precursors requires that each homologous chromosome pair be properly segregated to produce an exact haploid set of chromosomes. Genetic recombination, which provides a physical connection between homologous chromosomes...

  8. Epigenetic control of meiotic recombination in plants.

    Science.gov (United States)

    Yelina, Natasha; Diaz, Patrick; Lambing, Christophe; Henderson, Ian R

    2015-03-01

    Meiotic recombination is a deeply conserved process within eukaryotes that has a profound effect on patterns of natural genetic variation. During meiosis homologous chromosomes pair and undergo DNA double strand breaks generated by the Spo11 endonuclease. These breaks can be repaired as crossovers that result in reciprocal exchange between chromosomes. The frequency of recombination along chromosomes is highly variable, for example, crossovers are rarely observed in heterochromatin and the centromeric regions. Recent work in plants has shown that crossover hotspots occur in gene promoters and are associated with specific chromatin modifications, including H2A.Z. Meiotic chromosomes are also organized in loop-base arrays connected to an underlying chromosome axis, which likely interacts with chromatin to organize patterns of recombination. Therefore, epigenetic information exerts a major influence on patterns of meiotic recombination along chromosomes, genetic variation within populations and evolution of plant genomes.

  9. The stability of recombined milk fat globules

    NARCIS (Netherlands)

    Melsen, J.P.

    1987-01-01

    The stability of the fat globules in recombined milk products against creaming, flocculation, clustering, partial coalescence and real coalescence, with the emphasis on partial coalescence, was studied. (partial) Coalescence was characterized by determining changes in globule size

  10. Recombinant viral vaccines for enzootic bovine leucosis

    National Research Council Canada - National Science Library

    Daniel, R C; Gatei, M H; Good, M F; Boyle, D B; Lavin, M F

    1993-01-01

    ...) and part of gp30 of the bovine leukaemia virus (BLV) are described. It has been reported that vaccination of sheep with recombinant VV vaccines containing the complete env gene appears to protect sheep against challenge infection with BLV...

  11. Intermediate bands and non radiative recombination

    OpenAIRE

    Tablero Crespo, César; Martí Vega, Antonio; Fuertes Marrón, David; Antolín Fernández, Elisa; Luque López, Antonio

    2009-01-01

    The use of half-filled intermediate band materials has been proposed as a means to implement solar cells with efficiency exceeding that of single gap solar cells. An intermediate band can be regarded, at first, as a mere collection of energy levels within the semiconductor bandgap. However, its recombination properties are expected to be different from those traditionally attributed to deep levels. Hence, while deep centers behave mainly as non-radiative recombination centers, the IB is ...

  12. Paroxetine suppresses recombinant human P2X7 responses.

    Science.gov (United States)

    Dao-Ung, Phuong; Skarratt, Kristen K; Fuller, Stephen J; Stokes, Leanne

    2015-12-01

    P2X7 receptor (P2X7) activity may link inflammation to depressive disorders. Genetic variants of human P2X7 have been linked with major depression and bipolar disorders, and the P2X7 knockout mouse has been shown to exhibit anti-depressive-like behaviour. P2X7 is an ATP-gated ion channel and is a major regulator of the pro-inflammatory cytokine interleukin 1β (IL-1β) secretion from monocytes and microglia. We hypothesised that antidepressants may elicit their mood enhancing effects in part via modulating P2X7 activity and reducing inflammatory responses. In this study, we determined whether common psychoactive drugs could affect recombinant and native human P2X7 responses in vitro. Common antidepressants demonstrated opposing effects on human P2X7-mediated responses; paroxetine inhibited while fluoxetine and clomipramine mildly potentiated ATP-induced dye uptake in HEK-293 cells stably expressing recombinant human P2X7. Paroxetine inhibited dye uptake mediated by human P2X7 in a concentration-dependent manner with an IC(50) of 24 μM and significantly reduces ATP-induced inward currents. We confirmed that trifluoperazine hydrochloride suppressed human P2X7 responses (IC(50) of 6.4 μM). Both paroxetine and trifluoperazine did not inhibit rodent P2X7 responses, and mutation of a known residue (F 95L) did not alter the effect of either drug, suggesting neither drug binds at this site. Finally, we demonstrate that P2X7-induced IL-1β secretion from lipopolysaccharide (LPS)-primed human CD14(+) monocytes was suppressed with trifluoperazine and paroxetine.

  13. Dissociation of recombinant prion autocatalysis from infectivity.

    Science.gov (United States)

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication--that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.

  14. The kissing-loop motif is a preferred site of 5' leader recombination during replication of SL3-3 murine leukemia viruses in mice

    DEFF Research Database (Denmark)

    Lund, Anders Henrik; Mikkelsen, J G; Schmidt, J

    1999-01-01

    A panel of mouse T-cell lymphomas induced by SL3-3 murine leukemia virus (MLV) and three primer binding site mutants thereof (A. H. Lund, J. Schmidt, A. Luz, A. B. Sorensen, M. Duch, and F. S. Pedersen, J. Virol. 73:6117-6122, 1999) were analyzed for the occurrence of recombination between......, and the upstream part of the 5' untranslated region, enabled us to map recombination sites, guided by distinct scattered nucleotide differences. In 30 of 44 analyzed sequences, recombination was mapped to a 33-nucleotide similarity window coinciding with the kissing-loop stem-loop motif implicated in dimerization...... of the diploid genome. Interestingly, the recombination pattern preference found in replication-competent viruses from T-cell tumors is very similar to the pattern previously reported for retroviral vectors in cell culture experiments. The data therefore sustain the hypothesis that the kissing loop, presumably...

  15. Mouse models for cancer research

    OpenAIRE

    Zhang, Wei; Moore, Lynette; Ji, Ping

    2011-01-01

    Mouse models of cancer enable researchers to learn about tumor biology in complicated and dynamic physiological systems. Since the development of gene targeting in mice, cancer biologists have been among the most frequent users of transgenic mouse models, which have dramatically increased knowledge about how cancers form and grow. The Chinese Journal of Cancer will publish a series of papers reporting the use of mouse models in studying genetic events in cancer cases. This editorial is an ove...

  16. Generation of genetically modified embryonic stem cells for the development of knockout mouse animal model systems.

    Science.gov (United States)

    Robinson, Stephen D; Wilson, Stephen; Hodivala-Dilke, Kairbaan M

    2006-01-01

    The aim of our lab is to understand the contributions made by cell adhesion molecules in the processes of disease. Much of our recent work has focused on the role played by beta3-integrin in mediating pathological angiogenesis. It is fair to state that without the ability to manipulate the mouse genome, and specifically to create knockout mice, the advances we have made in this field would not be nearly as significant as they are. The ability to generate knockout mice depends on the two technological breakthroughs of the ability to isolate and culture mouse embryonic stem (ES) cells and the methods employed for achieving targeted gene replacement in these cells by homologous recombination. Here, we present the methods we have found to be successful, and that we routinely employ to grow and manipulate ES cells, as well as those to screen and identify homologous recombinants.

  17. Local Chromatin Features Including PU.1 and IKAROS Binding and H3K4 Methylation Shape the Repertoire of Immunoglobulin Kappa Genes Chosen for V(D)J Recombination

    Science.gov (United States)

    Matheson, Louise S.; Bolland, Daniel J.; Chovanec, Peter; Krueger, Felix; Andrews, Simon; Koohy, Hashem; Corcoran, Anne E.

    2017-01-01

    V(D)J recombination is essential for the generation of diverse antigen receptor (AgR) repertoires. In B cells, immunoglobulin kappa (Igκ) light chain recombination follows immunoglobulin heavy chain (Igh) recombination. We recently developed the DNA-based VDJ-seq assay for the unbiased quantitation of Igh VH and DH repertoires. Integration of VDJ-seq data with genome-wide datasets revealed that two chromatin states at the recombination signal sequence (RSS) of VH genes are highly predictive of recombination in mouse pro-B cells. It is unknown whether local chromatin states contribute to Vκ gene choice during Igκ recombination. Here we adapt VDJ-seq to profile the Igκ VκJκ repertoire and present a comprehensive readout in mouse pre-B cells, revealing highly variable Vκ gene usage. Integration with genome-wide datasets for histone modifications, DNase hypersensitivity, transcription factor binding and germline transcription identified PU.1 binding at the RSS, which was unimportant for Igh, as highly predictive of whether a Vκ gene will recombine or not, suggesting that it plays a binary, all-or-nothing role, priming genes for recombination. Thereafter, the frequency with which these genes recombine was shaped both by the presence and level of enrichment of several other chromatin features, including H3K4 methylation and IKAROS binding. Moreover, in contrast to the Igh locus, the chromatin landscape of the promoter, as well as of the RSS, contributes to Vκ gene recombination. Thus, multiple facets of local chromatin features explain much of the variation in Vκ gene usage. Together, these findings reveal shared and divergent roles for epigenetic features and transcription factors in AgR V(D)J recombination and provide avenues for further investigation of chromatin signatures that may underpin V(D)J-mediated chromosomal translocations. PMID:29204143

  18. Anti-Human Endoglin (hCD105 Immunotoxin—Containing Recombinant Single Chain Ribosome-Inactivating Protein Musarmin 1

    Directory of Open Access Journals (Sweden)

    Begoña Barriuso

    2016-06-01

    Full Text Available Endoglin (CD105 is an accessory component of the TGF-β receptor complex, which is expressed in a number of tissues and over-expressed in the endothelial cells of tumor neovasculature. Targeting endoglin with immunotoxins containing type 2 ribosome-inactivating proteins has proved an effective tool to reduce blood supply to B16 mice tumor xenografts. We prepared anti-endoglin immunotoxin (IT—containing recombinant musarmin 1 (single chain ribosome-inactivating proteins linked to the mouse anti-human CD105 44G4 mouse monoclonal antibody via N-succinimidyl 3-(2-pyridyldithio propionate (SPDP. The immunotoxin specifically killed L929 fibroblast mouse cells transfected with the short form of human endoglin with IC50 values in the range of 5 × 10−10 to 10−9 M.

  19. Tongue-mouse for quadriplegics

    Science.gov (United States)

    Nutt, Wolfgang; Arlanch, Christian; Nigg, Silvio; Staufert, Gerhard

    1998-06-01

    The full replacement of the PC-mouse through the tongue-mouse gives highly handicapped people like quadriplegics new chances in their life. The idea of the tongue-mouse was given high international attention at the inventory show at MUBA 1994 in Basel. At the Neu-Technikum Buchs in the Institute of Microsystem Technology, the development of the sensor system of the tongue-mouse took place. The system is based on piezo-ceramics as sensor material connected with anisotropic conductive adhesives on a flexible printed foil and the chip-on-flex technology. This sensor module is placed on a conventional dental plate fitted to the patient.

  20. Chimeric recombinant antibody fragments in cardiac troponin I immunoassay.

    Science.gov (United States)

    Hyytiä, Heidi; Heikkilä, Taina; Brockmann, Eeva-Christine; Kekki, Henna; Hedberg, Pirjo; Puolakanaho, Tarja; Lövgren, Timo; Pettersson, Kim

    2015-03-01

    To introduce a novel nanoparticle-based immunoassay for cardiac troponin I (cTnI) utilizing chimeric antibody fragments and to demonstrate that removal of antibody Fc-part and antibody chimerization decrease matrix related interferences. A sandwich-type immunoassay for cTnI based on recombinant chimeric (mouse variable/human constant) antigen binding (cFab) antibodies and intrinsically fluorescent nanoparticles was developed. To test whether using chimeric antibody fragments helps to avoid matrix related interferences, samples (n=39) with known amounts of triglycerides, bilirubin, rheumatoid factor (RF) or human anti-mouse antibodies (HAMAs) were measured with the novel assay, along with a previously published nanoparticle-based research assay with the same antibody epitopes. The limit of detection (LoD) was 3.30ng/L. Within-laboratory precision for 29ng/L and 2819ng/L cTnI were 13.7% and 15.9%, respectively. Regression analysis with Siemens ADVIA Centaur® yielded a slope (95% confidence intervals) of 0.18 (0.17-1.19) and a y-intercept of 1.94 (-1.28-3.91) ng/L. When compared to a previously published nanoparticle-based assay, the novel assay showed substantially reduced interference in the tested interference prone samples, 15.4 vs. 51.3%. A rheumatoid factor containing sample was decreased from 241ng/L to

  1. Recombination analysis based on the complete genome of bocavirus

    Directory of Open Access Journals (Sweden)

    Chen Shengxia

    2011-04-01

    Full Text Available Abstract Bocavirus include bovine parvovirus, minute virus of canine, porcine bocavirus, gorilla bocavirus, and Human bocaviruses 1-4 (HBoVs. Although recent reports showed that recombination happened in bocavirus, no systematical study investigated the recombination of bocavirus. The present study performed the phylogenetic and recombination analysis of bocavirus over the complete genomes available in GenBank. Results confirmed that recombination existed among bocavirus, including the likely inter-genotype recombination between HBoV1 and HBoV4, and intra-genotype recombination among HBoV2 variants. Moreover, it is the first report revealing the recombination that occurred between minute viruses of canine.

  2. Recombination hotspots and host susceptibility modulate the adaptive value of recombination during maize streak virus evolution

    Directory of Open Access Journals (Sweden)

    Monjane Adérito L

    2011-12-01

    Full Text Available Abstract Background Maize streak virus -strain A (MSV-A; Genus Mastrevirus, Family Geminiviridae, the maize-adapted strain of MSV that causes maize streak disease throughout sub-Saharan Africa, probably arose between 100 and 200 years ago via homologous recombination between two MSV strains adapted to wild grasses. MSV recombination experiments and analyses of natural MSV recombination patterns have revealed that this recombination event entailed the exchange of the movement protein - coat protein gene cassette, bounded by the two genomic regions most prone to recombination in mastrevirus genomes; the first surrounding the virion-strand origin of replication, and the second around the interface between the coat protein gene and the short intergenic region. Therefore, aside from the likely adaptive advantages presented by a modular exchange of this cassette, these specific breakpoints may have been largely predetermined by the underlying mechanisms of mastrevirus recombination. To investigate this hypothesis, we constructed artificial, low-fitness, reciprocal chimaeric MSV genomes using alternating genomic segments from two MSV strains; a grass-adapted MSV-B, and a maize-adapted MSV-A. Between them, each pair of reciprocal chimaeric genomes represented all of the genetic material required to reconstruct - via recombination - the highly maize-adapted MSV-A genotype, MSV-MatA. We then co-infected a selection of differentially MSV-resistant maize genotypes with pairs of reciprocal chimaeras to determine the efficiency with which recombination would give rise to high-fitness progeny genomes resembling MSV-MatA. Results Recombinants resembling MSV-MatA invariably arose in all of our experiments. However, the accuracy and efficiency with which the MSV-MatA genotype was recovered across all replicates of each experiment depended on the MSV susceptibility of the maize genotypes used and the precise positions - in relation to known recombination hotspots

  3. MouseBook: an integrated portal of mouse resources

    Science.gov (United States)

    Blake, Andrew; Pickford, Karen; Greenaway, Simon; Thomas, Steve; Pickard, Amanda; Williamson, Christine M.; Adams, Niels C.; Walling, Alison; Beck, Tim; Fray, Martin; Peters, Jo; Weaver, Tom; Brown, Steve D. M.; Hancock, John M.; Mallon, Ann-Marie

    2010-01-01

    The MouseBook (http://www.mousebook.org) databases and web portal provide access to information about mutant mouse lines held as live or cryopreserved stocks at MRC Harwell. The MouseBook portal integrates curated information from the MRC Harwell stock resource, and other Harwell databases, with information from external data resources to provide value-added information above and beyond what is available through other routes such as International Mouse Stain Resource (IMSR). MouseBook can be searched either using an intuitive Google style free text search or using the Mammalian Phenotype (MP) ontology tree structure. Text searches can be on gene, allele, strain identifier (e.g. MGI ID) or phenotype term and are assisted by automatic recognition of term types and autocompletion of gene and allele names covered by the database. Results are returned in a tabbed format providing categorized results identified from each of the catalogs in MouseBook. Individual result lines from each catalog include information on gene, allele, chromosomal location and phenotype, and provide a simple click-through link to further information as well as ordering the strain. The infrastructure underlying MouseBook has been designed to be extensible, allowing additional data sources to be added and enabling other sites to make their data directly available through MouseBook. PMID:19854936

  4. Heterogeneous recombination among Hepatitis B virus genotypes.

    Science.gov (United States)

    Castelhano, Nadine; Araujo, Natalia M; Arenas, Miguel

    2017-10-01

    The rapid evolution of Hepatitis B virus (HBV) through both evolutionary forces, mutation and recombination, allows this virus to generate a large variety of adapted variants at both intra and inter-host levels. It can, for instance, generate drug resistance or the diverse viral genotypes that currently exist in the HBV epidemics. Concerning the latter, it is known that recombination played a major role in the emergence and genetic diversification of novel genotypes. In this regard, the quantification of viral recombination in each genotype can provide relevant information to devise expectations about the evolutionary trends of the epidemic. Here we measured the amount of this evolutionary force by estimating global and local recombination rates in >4700 HBV complete genome sequences corresponding to nine (A to I) HBV genotypes. Counterintuitively, we found that genotype E presents extremely high levels of recombination, followed by genotypes B and C. On the other hand, genotype G presents the lowest level, where recombination is almost negligible. We discuss these findings in the light of known characteristics of these genotypes. Additionally, we present a phylogenetic network to depict the evolutionary history of the studied HBV genotypes. This network clearly classified all genotypes into specific groups and indicated that diverse pairs of genotypes are derived from a common ancestor (i.e., C-I, D-E and, F-H) although still the origin of this virus presented large uncertainty. Altogether we conclude that the amount of observed recombination is heterogeneous among HBV genotypes and that this heterogeneity can influence on the future expansion of the epidemic. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Burn mouse models

    DEFF Research Database (Denmark)

    Calum, Henrik; Høiby, Niels; Moser, Claus

    2014-01-01

    Severe thermal injury induces immunosuppression, involving all parts of the immune system, especially when large fractions of the total body surface area are affected. An animal model was established to characterize the burn-induced immunosuppression. In our novel mouse model a 6 % third-degree b......Severe thermal injury induces immunosuppression, involving all parts of the immune system, especially when large fractions of the total body surface area are affected. An animal model was established to characterize the burn-induced immunosuppression. In our novel mouse model a 6 % third......-degree burn injury was induced with a hot-air blower. The third-degree burn was confirmed histologically. At 48 h, a decline in the concentration of peripheral blood leucocytes was observed in the group of mice with burn wound. The reduction was ascribed to the decline in concentration of polymorphonuclear...... neutrophil leucocytes and monocytes. When infecting the skin with Pseudomonas aeruginosa, a dissemination of bacteria was observed only in the burn wound group. Histological characterization of the skin showed an increased polymorphonuclear neutrophil granulocytes dominated inflammation in the group of mice...

  6. Genetic organization of the agouti region of the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Siracusa, L.D.; Russell, L.B.; Eicher, E.M.; Corrow, D.J.; Copeland, N.G.; Jenkins, N.A.

    1987-09-01

    The agouti locus on mouse chromosome 2 acts via the hair follicle to control the melanic type and distribution of hair pigments. The diverse phenotypes associated with various agouti mutations have led to speculation about the organization of the agouti locus. Earlier studies indicated that two presumed agouti alleles, lethal yellow (A/sup y/) and lethal light-bellied nonagouti (a/sup x/), are pseudoallelic. The authors present genetic data showing probable recombination between A/sup y/ and three agouti mutations (a/sup t/, a, and a/sup x/), which suggest that A/sup y/ is a pseudoallele of the agouti locus. The close linkage of an endogenous ecotropic murine leukemia provirus, Emv-15, to A/sup y/ provides a molecular access to genes at or near the agouti locus. However, previous studies suggested that the Emv-15 locus can recombine with some agouti alleles and therefore they analyzed mice from recombinant inbred strains and backcrosses to measure the genetic distance between various agouti alleles and the Emv-15 locus. The data indicate that the Emv-15 locus is less the 0.3 cM from the agouti locus. These experiments provide a conceptual framework for initiating chromosome walking experiments designed to retrieve sequences from the agouti locus and give new insight into the genetic organization of the agouti region.

  7. [Eucaryotic expression and bioactivity analysis of the recombinant HSV-gD1].

    Science.gov (United States)

    Wang, Zhengmao; Li, Lin; Guan, Wenyan; Li, Yuexi

    2010-05-01

    Envelope proteins of herpes simplex virus (HSV) plays a vital role not only in the infection process of adsorption and invasion but also in the stimulation to the organism that gives rise to immune response. Among the envelope proteins, glycoprotein D (gD), which can induce specific immune response, are the primary targets of humoral and cellular immunity of the host. In order to analyze the antigenicity and immunogenicity of HSV-gD1, we chemically synthesized the extracellular domain fragment gene of gD1, cloned it into eucaryotic expression vector pCEP4, and transfected the HEK293 cells with the recombinant vector. Then we identified the recombinant protein by Western blotting, and detected antigenicity of the protein by ELISA. Finally, we used the purified gD1 protein to immunize Kunming mice in 1, 3, 5 weeks, and collected antiserum in 3, 5 and 7 weeks. We titrated the sera for the detection of anti gD1 using an ELISA assay. Gene sequencing analysis demonstrated that the recombinant plasmid pCEP4-gD1 was constructed successfully. Western blotting analysis indicated one major protein band, which molecular weights is approximate 46 kDa corresponding to the truncated forms of gD1 protein, was observed. ELISA assay showed that the expressed recombinant protein gD1 had good antigenicity. After the third immunization, antibody titer of the mouse anti-gD1 was at least 5 x10(3). The successful expression of the recombinant protein gD1, which can induce humoral immune response, lays a foundation for serological diagnosis and vaccine study of HSV.

  8. Immunization with recombinant actin from Trypanosoma evansi induces protective immunity against T. evansi, T. equiperdum and T. b. brucei infection.

    Science.gov (United States)

    Li, San-Qiang; Yang, Wu-Biao; Lun, Zhao-Rong; Ma, Ling-Jun; Xi, Shou-Min; Chen, Qun-Li; Song, Xiao-Wei; Kang, Jian; Yang, Lan-Ze

    2009-01-01

    Actin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi actin shows 100%, 98.7%, and 93.1%, homology with Trypanosoma equiperdum, Trypanosoma brucei brucei, and Trypanosoma cruzi. Recombinant actin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant actin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818, and T. b. brucei STIB 940, showing 63.3%, 56.7%, and 53.3% protection, respectively. Serum collected from the rabbit immunized with recombinant actin inhibited the growth of T. evansi, T. equiperdum, and T. b. brucei in vitro cultivation. Serum from mice and rabbits immunized with recombinant actin only recognized T. evansi actin but not mouse actin. The results of this study suggest that the recombinant T. evansi actin induces protective immunity against T. evansi, T. equiperdum, and T. b. brucei infection and may be useful in the development of a vaccine with other cytoskeletal proteins to prevent animal trypanosomiasis caused by these three trypanosome species.

  9. Ion recombination correction in carbon ion beams.

    Science.gov (United States)

    Rossomme, S; Hopfgartner, J; Lee, N D; Delor, A; Thomas, R A S; Romano, F; Fukumura, A; Vynckier, S; Palmans, H

    2016-07-01

    In this work, ion recombination is studied as a function of energy and depth in carbon ion beams. Measurements were performed in three different passively scattered carbon ion beams with energies of 62 MeV/n, 135 MeV/n, and 290 MeV/n using various types of plane-parallel ionization chambers. Experimental results were compared with two analytical models for initial recombination. One model is generally used for photon beams and the other model, developed by Jaffé, takes into account the ionization density along the ion track. An investigation was carried out to ascertain the effect on the ion recombination correction with varying ionization chamber orientation with respect to the direction of the ion tracks. The variation of the ion recombination correction factors as a function of depth was studied for a Markus ionization chamber in the 62 MeV/n nonmodulated carbon ion beam. This variation can be related to the depth distribution of linear energy transfer. Results show that the theory for photon beams is not applicable to carbon ion beams. On the other hand, by optimizing the value of the ionization density and the initial mean-square radius, good agreement is found between Jaffé's theory and the experimental results. As predicted by Jaffé's theory, the results confirm that ion recombination corrections strongly decrease with an increasing angle between the ion tracks and the electric field lines. For the Markus ionization chamber, the variation of the ion recombination correction factor with depth was modeled adequately by a sigmoid function, which is approximately constant in the plateau and strongly increasing in the Bragg peak region to values of up to 1.06. Except in the distal edge region, all experimental results are accurately described by Jaffé's theory. Experimental results confirm that ion recombination in the investigated carbon ion beams is dominated by initial recombination. Ion recombination corrections are found to be significant and cannot be

  10. [Cloning of mouse TLR-2 gene and its expression in Pichia pastroris].

    Science.gov (United States)

    Zhao, Wen-zhong; Jiang, Hai-yan; Liu, Yan-jun; Zhu, Ping; Fu, Ning

    2004-07-01

    To clone the mouse TLR-2 gene and to express it in Pichia pastroris. Full-length gene encoding mouse Toll-like receptor 2 (mTLR-2) was amplified by RT-PCR, cloned into pUCm-T vector, and confirmed by sequencing. The target gene was then inserted into Pichia pastroris expression vector pPICZalphaC, which was transformed into Pichia pastroris. The recombinant Pichia pastroris was confirmed by PCR and RT-PCR. Expressed protein was identified by SDS-PAGE and Western blot. The full-length mTLR-2 gene(GenBank accession No.AY179346) was cloned. The homology of the cloned gene to published mTLR-2 gene reached 99.84%. The recombinant expression plasmid pPICZ- mTLR-2 was constructed successfully. SDS-PAGE analysis showed that the relative molecular mass(M(r)) of recombinant protein was about 97 000. Western blot analysis showed expressed product can react to rabbit anti- mTLR-2 antibody. The full-length mTLR-2 gene is cloned and the recombinant protein can be expressed in Pichia pastroris correctly.

  11. Recombination in Eukaryotic Single Stranded DNA Viruses

    Directory of Open Access Journals (Sweden)

    Philippe Roumagnac

    2011-09-01

    Full Text Available Although single stranded (ss DNA viruses that infect humans and their domesticated animals do not generally cause major diseases, the arthropod borne ssDNA viruses of plants do, and as a result seriously constrain food production in most temperate regions of the world. Besides the well known plant and animal-infecting ssDNA viruses, it has recently become apparent through metagenomic surveys of ssDNA molecules that there also exist large numbers of other diverse ssDNA viruses within almost all terrestrial and aquatic environments. The host ranges of these viruses probably span the tree of life and they are likely to be important components of global ecosystems. Various lines of evidence suggest that a pivotal evolutionary process during the generation of this global ssDNA virus diversity has probably been genetic recombination. High rates of homologous recombination, non-homologous recombination and genome component reassortment are known to occur within and between various different ssDNA virus species and we look here at the various roles that these different types of recombination may play, both in the day-to-day biology, and in the longer term evolution, of these viruses. We specifically focus on the ecological, biochemical and selective factors underlying patterns of genetic exchange detectable amongst the ssDNA viruses and discuss how these should all be considered when assessing the adaptive value of recombination during ssDNA virus evolution.

  12. Graded Recombination Layers for Multijunction Photovoltaics

    KAUST Repository

    Koleilat, Ghada I.

    2012-06-13

    Multijunction devices consist of a stack of semiconductor junctions having bandgaps tuned across a broad spectrum. In solar cells this concept is used to increase the efficiency of photovoltaic harvesting, while light emitters and detectors use it to achieve multicolor and spectrally tunable behavior. In series-connected current-matched multijunction devices, the recombination layers must allow the hole current from one cell to recombine, with high efficiency and low voltage loss, with the electron current from the next cell. We recently reported a tandem solar cell in which the recombination layer was implemented using a progression of n-type oxides whose doping densities and work functions serve to connect, with negligible resistive loss at solar current densities, the constituent cells. Here we present the generalized conditions for design of efficient graded recombination layer solar devices. We report the number of interlayers and the requirements on work function and doping of each interlayer, to bridge an work function difference as high as 1.6 eV. We also find solutions that minimize the doping required of the interlayers in order to minimize optical absorption due to free carriers in the graded recombination layer (GRL). We demonstrate a family of new GRL designs experimentally and highlight the benefits of the progression of dopings and work functions in the interlayers. © 2012 American Chemical Society.

  13. Polyploidization increases meiotic recombination frequency in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Rehmsmeier Marc

    2011-04-01

    Full Text Available Abstract Background Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination. Results Using two genetically linked transgenes providing seed-specific fluorescence, we compared a high number of progeny from diploid and tetraploid Arabidopsis plants. We show that rates of meiotic recombination in reciprocal crosses of genetically identical diploid and autotetraploid Arabidopsis plants were significantly higher in tetraploids compared to diploids. Although male and female gametogenesis differ substantially in meiotic recombination frequency, both rates were equally increased in tetraploids. To investigate whether multivalent formation in autotetraploids was responsible for the increased recombination rates, we also performed corresponding experiments with allotetraploid plants showing strict bivalent pairing. We found similarly increased rates in auto- and allotetraploids, suggesting that the ploidy effect is independent of chromosome pairing configurations. Conclusions The evolutionary success of polyploid plants in nature and under domestication has been attributed to buffering of mutations and sub- and neo-functionalization of duplicated genes. Should the data described here be representative for polyploid plants, enhanced meiotic recombination, and the resulting rapid creation of genetic diversity, could have also contributed to their prevalence.

  14. Cre-loxP-Mediated Recombination: General Principles and Experimental Considerations.

    Science.gov (United States)

    McLellan, Micheal A; Rosenthal, Nadia A; Pinto, Alexander R

    2017-03-02

    The cre-loxP-mediated recombination system (the "cre-loxP system") is an integral experimental tool for mammalian genetics and cell biology. Use of the system has greatly expanded our ability to precisely interrogate gene function in the mouse, providing both spatial and temporal control of gene expression. This has been largely due to the simplicity of its use and its adaptability to address diverse biological questions. While the use of the cre-loxP system is becoming increasingly widespread, in particular because of growing availability of conditional mouse mutants, many considerations need to be taken into account when utilizing the cre-loxP system. This review provides an overview of the cre-loxP system and its various permutations. It addresses the limitations of cre-loxP technology and related considerations for experimental design, and it discusses alternative strategies for site-specific genetic recombination and integration. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  15. Generation of Modified Pestiviruses by Targeted Recombination

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Bruun; Friis, Martin Barfred; Risager, Peter Christian

    Infectious cDNA clones are a prerequisite for directed genetic manipulation of pestivirus RNA genomes. We have developed a novel strategy to facilitate manipulation and rescue of modified pestiviruses from infectious cDNA clones based on bacterial artificial chromosomes (BACs). The strategy...... involves targeted modification of viral cDNA genomes, cloned within BACs, by Red/ET recombination-mediated mutagenesis in E.coli DH10B cells. Using recombination-mediated mutagenesis for the targeted design, the work can be expedited and focused in principal on any sequence within the viral genome...... and hence is not limited to the use of internal restriction sites. Rescue of modified pestiviruses can be obtained by electroporation of cell cultures with full-length RNA transcripts in vitro transcribed from the recombined BAC clones. We have used this approach to generate a series of new pestivirus BACs...

  16. Recombinant human erythropoietin in sports: a review

    Directory of Open Access Journals (Sweden)

    Rafael Maia de Almeida Bento

    2003-06-01

    Full Text Available Erythropoietin is an endogenous hormone of glicoproteic nature secreted by the kidneys and is the main regulator of the erythropoiesis. An alteration in its production generates a disturbance in the plasmatic concentration giving rise to several types of pathologies related to the hematopoietic system. The recombinant forms of erythropoietin have indiscriminately been used by athletes, mainly in endurance sports, by increasing the erythrocytes concentration, generating a better delivery of oxygen to the muscle tissue. The administration of recombinant erythropoietin was prohibited by the International Olympic Committee and its use considered as doping. This review has the intention to describe the physical, biological and pharmacokinetic properties of the endogenous erythropoietin, as well as its recombinant form, describing also its use in sports and the process of searching methodologies for its detection in doping control.

  17. A Recombinant Antibody-Expressing Influenza Virus Delays Tumor Growth in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Jennifer R. Hamilton

    2018-01-01

    Full Text Available Influenza A virus (IAV has shown promise as an oncolytic agent. To improve IAV as an oncolytic virus, we sought to design a transgenic virus expressing an immune checkpoint-inhibiting antibody during the viral life cycle. To test whether it was possible to express an antibody during infection, an influenza virus was constructed encoding the heavy chain of an antibody on the PB1 segment and the light chain of an antibody on the PA segment. This antibody-expressing IAV grows to high titers, and the antibodies secreted from infected cells exhibit comparable functionality with hybridoma-produced antibodies. To enhance the anti-cancer activity of IAV, an influenza virus was engineered to express a single-chain antibody antagonizing the immune checkpoint CTLA4 (IAV-CTLA4. In mice implanted with the aggressive B16-F10 melanoma, intratumoral injection with IAV-CTLA4 delayed the growth of treated tumors, mediated an abscopal effect, and increased overall survival.

  18. Mouse and human BAC transgenes recapitulate tissue-specific expression of the vitamin D receptor in mice and rescue the VDR-null phenotype.

    Science.gov (United States)

    Lee, Seong Min; Bishop, Kathleen A; Goellner, Joseph J; O'Brien, Charles A; Pike, J Wesley

    2014-06-01

    The biological actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) are mediated by the vitamin D receptor (VDR), which is expressed in numerous target tissues in a cell type-selective manner. Recent studies using genomic analyses and recombineered bacterial artificial chromosomes (BACs) have defined the specific features of mouse and human VDR gene loci in vitro. In the current study, we introduced recombineered mouse and human VDR BACs as transgenes into mice and explored their expression capabilities in vivo. Individual transgenic mouse strains selectively expressed BAC-derived mouse or human VDR proteins in appropriate vitamin D target tissues, thereby recapitulating the tissue-specific expression of endogenous mouse VDR. The mouse VDR transgene was also regulated by 1,25(OH)2D3 and dibutyryl-cAMP. When crossed into a VDR-null mouse background, both transgenes restored wild-type basal as well as 1,25(OH)2D3-inducible gene expression patterns in the appropriate tissues. This maneuver resulted in the complete rescue of the aberrant phenotype noted in the VDR-null mouse, including systemic features associated with altered calcium and phosphorus homeostasis and disrupted production of parathyroid hormone and fibroblast growth factor 23, and abnormalities associated with the skeleton, kidney, parathyroid gland, and the skin. This study suggests that both mouse and human VDR transgenes are capable of recapitulating basal and regulated expression of the VDR in the appropriate mouse tissues and restore 1,25(OH)2D3 function. These results provide a baseline for further dissection of mechanisms integral to mouse and human VDR gene expression and offer the potential to explore the consequence of selective mutations in VDR proteins in vivo.

  19. Whole mouse cryo-imaging

    Science.gov (United States)

    Wilson, David; Roy, Debashish; Steyer, Grant; Gargesha, Madhusudhana; Stone, Meredith; McKinley, Eliot

    2008-03-01

    The Case cryo-imaging system is a section and image system which allows one to acquire micron-scale, information rich, whole mouse color bright field and molecular fluorescence images of an entire mouse. Cryo-imaging is used in a variety of applications, including mouse and embryo anatomical phenotyping, drug delivery, imaging agents, metastastic cancer, stem cells, and very high resolution vascular imaging, among many. Cryo-imaging fills the gap between whole animal in vivo imaging and histology, allowing one to image a mouse along the continuum from the mouse -> organ -> tissue structure -> cell -> sub-cellular domains. In this overview, we describe the technology and a variety of exciting applications. Enhancements to the system now enable tiled acquisition of high resolution images to cover an entire mouse. High resolution fluorescence imaging, aided by a novel subtraction processing algorithm to remove sub-surface fluorescence, makes it possible to detect fluorescently-labeled single cells. Multi-modality experiments in Magnetic Resonance Imaging and Cryo-imaging of a whole mouse demonstrate superior resolution of cryo-images and efficiency of registration techniques. The 3D results demonstrate the novel true-color volume visualization tools we have developed and the inherent advantage of cryo-imaging in providing unlimited depth of field and spatial resolution. The recent results continue to demonstrate the value cryo-imaging provides in the field of small animal imaging research.

  20. Recombinant microorganisms for increased production of organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  1. Recombinant microorganisms for increased production of organic acids

    Science.gov (United States)

    Yi, Jian [East Lansing, MI; Kleff, Susanne [East Lansing, MI; Guettler, Michael V [Holt, MI

    2012-02-21

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  2. Cloning of a hamster anti-mouse CD79B antibody sequences and identification of a new hamster immunoglobulin lambda constant IGLC gene region.

    Science.gov (United States)

    Haggart, Ryan; Perera, Jason; Huang, Haochu

    2013-06-01

    Anti-CD79 antibodies have been effective at targeting B cell lymphoma cells and depleting B cells in animal models. In order to engineer recombinant antibodies with additional effector functions in mice, we cloned and sequenced the full-length cDNAs of the heavy and light chain of a hamster anti-mouse CD79B antibody. Although hamster antibodies represent a unique source of monoclonal antibodies against mouse, rat, and human antigens, sequence information of hamster immunoglobulins (IG) is sparse. Here, we report a new hamster (Cricetulus migratorius) IG lambda constant (IGLC) gene region that is most homologous to mouse IGLC2 and IGLC3.

  3. Partial agonism of taurine at gamma-containing native and recombinant GABAA receptors.

    Directory of Open Access Journals (Sweden)

    Olaf Kletke

    Full Text Available Taurine is a semi-essential sulfonic acid found at high concentrations in plasma and mammalian tissues which regulates osmolarity, ion channel activity and glucose homeostasis. The structural requirements of GABAA-receptors (GABAAR gated by taurine are not yet known. We determined taurine potency and efficacy relative to GABA at different types of recombinant GABAAR occurring in central histaminergic neurons of the mouse hypothalamic tuberomamillary nucleus (TMN which controls arousal. At binary α(1/2β(1/3 receptors taurine was as efficient as GABA, whereas incorporation of the γ(1/2 subunit reduced taurine efficacy to 60-90% of GABA. The mutation γ(2F77I, which abolishes zolpidem potentiation, significantly reduced taurine efficacy at recombinant and native receptors compared to the wild type controls. As taurine was a full- or super- agonist at recombinant αxβ1δ-GABAAR, we generated a chimeric γ(2 subunit carrying the δ subunit motif around F77 (MTVFLH. At α(1/2β(1γ2(MTVFLH receptors taurine became a super-agonist, similar to δ-containing ternary receptors, but remained a partial agonist at β3-containing receptors. In conclusion, using site-directed mutagenesis we found structural determinants of taurine's partial agonism at γ-containing GABAA receptors. Our study sheds new light on the β1 subunit conferring the widest range of taurine-efficacies modifying GABAAR function under (pathophysiological conditions.

  4. Resolving RAD51C function in late stages of homologous recombination

    Directory of Open Access Journals (Sweden)

    Kuznetsov Sergey G

    2007-06-01

    Full Text Available Abstract DNA double strand breaks are efficiently repaired by homologous recombination. One of the last steps of this process is resolution of Holliday junctions that are formed at the sites of genetic exchange between homologous DNA. Although various resolvases with Holliday junctions processing activity have been identified in bacteriophages, bacteria and archaebacteria, eukaryotic resolvases have been elusive. Recent biochemical evidence has revealed that RAD51C and XRCC3, members of the RAD51-like protein family, are involved in Holliday junction resolution in mammalian cells. However, purified recombinant RAD51C and XRCC3 proteins have not shown any Holliday junction resolution activity. In addition, these proteins did not reveal the presence of a nuclease domain, which raises doubts about their ability to function as a resolvase. Furthermore, oocytes from infertile Rad51C mutant mice exhibit precocious separation of sister chromatids at metaphase II, a phenotype that reflects a defect in sister chromatid cohesion, not a lack of Holliday junction resolution. Here we discuss a model to explain how a Holliday junction resolution defect can lead to sister chromatid separation in mouse oocytes. We also describe other recent in vitro and in vivo evidence supporting a late role for RAD51C in homologous recombination in mammalian cells, which is likely to be resolution of the Holliday junction.

  5. A Non-pathogenic Recombinant Leishmania Expressing Lipophosphoglycan 3 Against Experimental Infection with Leishmania infantum.

    Science.gov (United States)

    Pirdel, L; Farajnia, S

    2017-07-01

    Visceral leishmaniasis (VL) is caused by Leishmania infantum in the Mediterranean basin and affects primarily children and immunosuppressed individuals. Various strategies of vaccination have so far been examined by either protein or DNA without achievable complete protection against the disease. The live non-pathogenic lizard parasite, Leishmania tarentolae, expressing elected Leishmania antigens has recently provided a promising new approach as a safe and effective live vaccine candidate to prevent leishmaniasis. Here, we evaluated the immunoprotective potential of a live recombinant L. tarentolae expressing Lipophosphoglycan 3 (LPG3) antigen against L. infantum infection in BALB/c mice. Results indicated that the administration of live recombinant Leishmania produced a significant high level of IFN-γ accompanied by reduced levels of IL-10 as compared to wild-type parasites as live vaccine control, thus suggesting the induction of a Th1-type immune response in a mouse model of visceral leishmaniasis. Analysis of the IgG antibody response also showed high levels of IgG2a relative to IgG1 in sera of mice immunized with recombinant Leishmania parasites. However, immune responses elicited by this live vaccine conferred partial protection against infectious challenge. Therefore, further studies are required to increase its protective efficacy. © 2017 The Foundation for the Scandinavian Journal of Immunology.

  6. A potent in vivo anti-tumor efficacy of novel recombinant type I interferon

    Science.gov (United States)

    Zhang, Kang-Jian; Yin, Xiao-Fei; Yang, Yuan-Qin; Li, Hui-Ling; Xu, Yan-Ni; Chen, Lie-Yang; Liu, Xi-Jun; Yuan, Su-Jing; Fang, Xian-Long; Xiao, Jing; Wu, Shuai; Xu, Hai-Neng; Chu, Liang; Katlinski, Kanstantsin V.; Katlinskaya, Yuliya V.; Guo, Rong-Bing; Wei, Guang-Wen; Wang, Da-Cheng; Liu, Xin-Yuan; Fuchs, Serge Y.

    2016-01-01

    Purpose Anti-proliferative, antiviral, and immunomodulatory activities of endogenous type I interferons (IFN1) prompt the design of recombinant IFN1 for therapeutic purposes. However, most of designed interferons exhibited suboptimal therapeutic efficacies against solid tumors. Here we report evaluation of the in vitro and in vivo anti-tumorigenic activities of a novel recombinant interferon termed sIFN-I. Experimental Design We compared primary and tertiary structures of sIFN-I with its parental human IFNα-2b, as well as affinities of these ligands for IFN1 receptor chains and pharmacokinetics. These IFN1 species were also compared for their ability to induce JAK-STAT signaling and expression of the IFN1-stimulated genes and to elicit anti-tumorigenic effects. Effects of sIFN-I on tumor angiogenesis and immune infiltration were also tested in transplanted and genetically engineered immunocompetent mouse models. Results sIFN-I displayed greater affinity for IFNAR1 (over IFNAR2) chain of the IFN1 receptor and elicited a greater extent of IFN1 signaling and expression of IFN-inducible genes in human cells. Unlike IFNα-2b, sIFN-I induced JAK-STAT signaling in mouse cells and exhibited an extended half-life in mice. Treatment with sIFN-I inhibited intratumoral angiogenesis, increased CD8+ T cell infiltration, and robustly suppressed growth of transplantable and genetically engineered tumors in immune-deficient and immune-competent mice. Conclusions These findings define sIFN-I as a novel recombinant IFN1 with potent preclinical anti-tumorigenic effects against solid tumor thereby prompting the assessment of sIFN-I clinical efficacy in humans. PMID:27683179

  7. A Potent In Vivo Antitumor Efficacy of Novel Recombinant Type I Interferon.

    Science.gov (United States)

    Zhang, Kang-Jian; Yin, Xiao-Fei; Yang, Yuan-Qin; Li, Hui-Ling; Xu, Yan-Ni; Chen, Lie-Yang; Liu, Xi-Jun; Yuan, Su-Jing; Fang, Xian-Long; Xiao, Jing; Wu, Shuai; Xu, Hai-Neng; Chu, Liang; Katlinski, Kanstantsin V; Katlinskaya, Yuliya V; Guo, Rong-Bing; Wei, Guang-Wen; Wang, Da-Cheng; Liu, Xin-Yuan; Fuchs, Serge Y

    2017-04-15

    Purpose: Antiproliferative, antiviral, and immunomodulatory activities of endogenous type I IFNs (IFN1) prompt the design of recombinant IFN1 for therapeutic purposes. However, most of the designed IFNs exhibited suboptimal therapeutic efficacies against solid tumors. Here, we report evaluation of the in vitro and in vivo antitumorigenic activities of a novel recombinant IFN termed sIFN-I.Experimental Design: We compared primary and tertiary structures of sIFN-I with its parental human IFNα-2b, as well as affinities of these ligands for IFN1 receptor chains and pharmacokinetics. These IFN1 species were also compared for their ability to induce JAK-STAT signaling and expression of the IFN1-stimulated genes and to elicit antitumorigenic effects. Effects of sIFN-I on tumor angiogenesis and immune infiltration were also tested in transplanted and genetically engineered immunocompetent mouse models.Results: sIFN-I displayed greater affinity for IFNAR1 (over IFNAR2) chain of the IFN1 receptor and elicited a greater extent of IFN1 signaling and expression of IFN-inducible genes in human cells. Unlike IFNα-2b, sIFN-I induced JAK-STAT signaling in mouse cells and exhibited an extended half-life in mice. Treatment with sIFN-I inhibited intratumoral angiogenesis, increased CD8+ T-cell infiltration, and robustly suppressed growth of transplantable and genetically engineered tumors in immunodeficient and immunocompetent mice.Conclusions: These findings define sIFN-I as a novel recombinant IFN1 with potent preclinical antitumorigenic effects against solid tumor, thereby prompting the assessment of sIFN-I clinical efficacy in humans. Clin Cancer Res; 23(8); 2038-49. ©2016 AACR. ©2016 American Association for Cancer Research.

  8. V(D)J recombination frequency is affected by the sequence interposed between a pair of recombination signals: sequence comparison reveals a putative recombinational enhancer element

    DEFF Research Database (Denmark)

    Roch, F A; Hobi, R; Berchtold, M W

    1997-01-01

    The immunoglobulin heavy chain intron enhancer (Emu) not only stimulates transcription but also V(D)J recombination of chromosomally integrated recombination substrates. We aimed at reproducing this effect in recombination competent cells by transient transfection of extrachromosomal substrates...... respectively, can markedly affect the frequency of V(D)J recombination. We report that the entire Emu, the Emu core as well as its flanking 5' and 3' matrix associated regions (5' and 3' MARs) upregulate V(D)J recombination while the downstream section of the 3' MAR of Emu does not. Also, prokaryotic sequences...

  9. The mouse homologue of the polycystic kidney disease gene (Pkd1) is a single-copy gene

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, P.G.; Loehning, C.; Frischauf, A.M. [Imperial Cancer Research Fund, London (United Kingdom)] [and others

    1996-06-01

    The mouse homologue of the polycystic kidney disease 1 gene (PKD1) was mapped to chromosome 17 using somatic cell hybrid, BXD recombinant inbred strains, and FISH. The gene is located within a previously defined conserved synteny group that includes the mouse homologue of tuberous sclerosis 2 (TSC2) and is linked to the {alpha} globin pseudogene Hba-ps4. Although the human genome contains multiple copies of genes related to PKD1, there is no evidence for more than one copy in the mouse genome. Like their human counterparts, the mouse Tsc2 and Pkd1 genes are arranged in a tail-to-tail orientation with a distance of only 63 bp between the polyadenylation signals of the two genes. 17 refs., 3 figs.

  10. Adeno-associated-virus-mediated transduction of the mammary gland enables sustained production of recombinant proteins in milk.

    Science.gov (United States)

    Wagner, Stefan; Thresher, Rosemary; Bland, Ross; Laible, Götz

    2015-10-14

    Biopharming for the production of recombinant pharmaceutical proteins in the mammary gland of transgenic animals is an attractive but laborious alternative compared to mammalian cell fermentation. The disadvantage of the lengthy process of genetically modifying an entire animal could be circumvented with somatic transduction of only the mammary epithelium with recombinant, replication-defective viruses. While other viral vectors offer very limited scope for this approach, vectors based on adeno-associated virus (AAV) appear to be ideal candidates because AAV is helper-dependent, does not induce a strong immune response and has no association with disease. Here, we sought to test the suitability of recombinant AAV (rAAV) for biopharming. Using reporter genes, we showed that injected rAAV efficiently transduced mouse mammary cells. When rAAV encoding human myelin basic protein (hMBP) was injected into the mammary glands of mice and rabbits, this resulted in the expression of readily detectable protein levels of up to 0.5 g/L in the milk. Furthermore we demonstrated that production of hMBP persisted over extended periods and that protein expression could be renewed in a subsequent lactation by re-injection of rAAV into a previously injected mouse gland.

  11. Recombinant Poliovirus circulation among healthy children ...

    African Journals Online (AJOL)

    Administrator

    In order to assess the level of polio virus with natural recombinant genome and wild polio virus circulating in the environment of healthy children aged 0 to 5 years in Abidjan, 130 polio viruses made up of 26 polio type 1, 55 type 2 and 49 type 3 were identified by neutralisation test with monoclonal antibodies and restriction ...

  12. Recombinant human endostatin reduces hypertrophic scar ...

    African Journals Online (AJOL)

    Department of Otolaryngology, First Affiliated Hospital of Chongqing Medical University, Chongqing,. China; pearl1984@sina.com. 3. Department of Burn and Plastic Surgery, First Affiliated Hospital of Chongqing Medical University,. Chongqing, China; CQXuebin@126.com. Abstract. Background: Recombinant human ...

  13. Expression optimisation of recombinant α-Larabinofuranosidase ...

    African Journals Online (AJOL)

    Expression optimisation of recombinant α-Larabinofuranosidase from Aspergillus niger ATCC 120120 in Pichia pastoris and its biochemical characterisation. NI Alias, NM Mahadi, NM Mahadi, AMA Murad, AMA Murad, FDA Bakar, FDA Bakar, A Rabu, A Rabu, RM Illias, RM Illias ...

  14. Expression of recombinant Streptokinase from local Egyptian ...

    African Journals Online (AJOL)

    We reported for the first time the expression of a recombinant SK from a local Streptococcus strain. When produced on industrial scale this r-SK may substantially contribute to reducing the costs of thrombolytic therapy in developing countries. In this study, a highly purified r-SK from Streptococcus sp. isolated from Egyptian ...

  15. Expression, purification and characterization of recombinant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... A recombinant targeting bifunctional hirudin was expressed in the yeast Pichia pastoris. In order to decrease the side effects of hirudin and increase its activity to prevent arterial thrombus, we fused a factor Xa (FXa) recognition sequence into N' of hirudin, while maintaining the activity of natural hirudin.

  16. Ultramicroscopic observation of recombinant adenoassociated virus ...

    African Journals Online (AJOL)

    Ultramicroscopic observation of recombinant adenoassociated virus type 2 on the surface of formvarcarbon coated copper grids under different relative humidity and incubation time using negative ... Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader.

  17. EXPRESSION AND CHARACTERIZATION OF RECOMBINANT β ...

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    ABSTRACT. Recombinant β-glucosidase (EC 3.2.1.21) from Aspergillus nidulans AN2227 was expressed using Buffered Methanol. Complex Medium (BMMY). Purification was conducted using ammonium sulphate precipitation and anion exchange chromatography on DEAE-Sephadex A-50 column. The enzyme.

  18. Production, purification and characterization of two recombinant ...

    African Journals Online (AJOL)

    Two recombinant DNA-derived variants of ovine growth hormone were produced, purified, characterized and compared with the authentic pituitary derived GH. The variants oGH3 and oGH5 were isolated by differential centrifugation method and were purified after refolding by ion-exchange chromatography and gel filtration ...

  19. Carbon source feeding strategies for recombinant protein ...

    African Journals Online (AJOL)

    Pichia pastoris and Pichia methanolica have been used as expression systems for the production of recombinant protein. The main problems of the production are the slow hierarchic consumption of ethanol and acetate which cause toxicity problems due to methanol accumulation when this surpasses 0.5 gl-1. In some ...

  20. Production, purification and characterization of two recombinant ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... ... Barash I, Hadari D, Levanon A, Gorecki M, Gertler. A (1987). Comparative study of in vitro and in vivo modulation of lactogenic and somatotropic receptors by native human growth hormone and its modified analog prepared by recombinant deoxyribonucleic acid technology. Endocrinology 121: 414-419.

  1. CATALYTIC RECOMBINER FOR A NUCLEAR REACTOR

    Science.gov (United States)

    King, L.D.P.

    1960-07-01

    A hydrogen-oxygen recombiner is described for use with water-boiler type reactors. The catalyst used is the wellknown platinized alumina, and the novelty lies in the structural arrangement used to prevent flashback through the gas input system. The recombiner is cylindrical, the gases at the input end being deflected by a baffle plate through a first flashback shield of steel shot into an annular passage adjacent to and extending the full length of the housing. Below the baffle plate the gases flow first through an outer annular array of alumina pellets which serve as a second flashback shield, a means of distributing the flowing gases evenly and as a means of reducing radiation losses to the walls. Thereafter the gases flow inio the centrally disposed catalyst bed where recombination is effected. The steam and uncombined gases flow into a centrally disposed cylindrical passage inside the catalyst bod and thereafter out through the exit port. A high rate of recombination is effected.

  2. Speciation trajectories in recombining bacterial species.

    Directory of Open Access Journals (Sweden)

    Pekka Marttinen

    2017-07-01

    Full Text Available It is generally agreed that bacterial diversity can be classified into genetically and ecologically cohesive units, but what produces such variation is a topic of intensive research. Recombination may maintain coherent species of frequently recombining bacteria, but the emergence of distinct clusters within a recombining species, and the impact of habitat structure in this process are not well described, limiting our understanding of how new species are created. Here we present a model of bacterial evolution in overlapping habitat space. We show that the amount of habitat overlap determines the outcome for a pair of clusters, which may range from fast clonal divergence with little interaction between the clusters to a stationary population structure, where different clusters maintain an equilibrium distance between each other for an indefinite time. We fit our model to two data sets. In Streptococcus pneumoniae, we find a genomically and ecologically distinct subset, held at a relatively constant genetic distance from the majority of the population through frequent recombination with it, while in Campylobacter jejuni, we find a minority population we predict will continue to diverge at a higher rate. This approach may predict and define speciation trajectories in multiple bacterial species.

  3. Recombination mechanisms and doping density in silicon

    Science.gov (United States)

    Passari, Luigi; Susi, Enrichetta

    1983-07-01

    Carrier recombination in silicon is analyzed as a function of doping density. Two mechanisms are identified: one for the low concentration range and one, of the Auger type, for the high concentration range. Disagreements with the theoretical predictions for the Auger process are discussed and empirical laws connecting lifetime to dopant concentration are determined.

  4. Algae-based oral recombinant vaccines

    Directory of Open Access Journals (Sweden)

    Elizabeth A Specht

    2014-02-01

    Full Text Available Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae are poised to become the next candidate in recombinant subunit vaccine production, and they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally-delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and system immune reactivity.

  5. The Role of Recombinant Genetics in Humanism.

    Science.gov (United States)

    Jacobs, Troy A.

    1983-01-01

    To eliminate the public's fear of recombinant genetics the important link between science and the humanities should be part of the educational system. Universal applied genetics guidelines are needed that encompass philosophical and technical issues. Biological advances can revitalize humankind in the future. (AM)

  6. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Purpose: To develop processes for effective isolation and purification of recombinant human plasminogen activator (rhPA) from transgenic rabbit milk. Methods: Immunoaffinity chromatography was selected and improved by a special polyol-responsive monoclonal antibody (PR-mAb). Alteplase was used as immunogen ...

  7. Algae-based oral recombinant vaccines

    Science.gov (United States)

    Specht, Elizabeth A.; Mayfield, Stephen P.

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for “molecular pharming” in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity. PMID:24596570

  8. Recombinant Bovine Growth Hormone Criticism Grows.

    Science.gov (United States)

    Gaard, Greta

    1995-01-01

    Discusses concerns related to the use of recombinant bovine growth hormone in the United States and other countries. Analyses the issue from the perspectives of animal rights, human health, world hunger, concerns of small and organic farmers, costs to the taxpayer, and environmental questions. A sidebar discusses Canadian review of the hormone.…

  9. Recombination and chiasmata: few but intriguing discrepancies.

    Science.gov (United States)

    Sybenga, J

    1996-06-01

    The paradigm that meiotic recombination and chiasmata have the same basis has been challenged, primarily for plants. High resolution genetic mapping frequently results in maps with lengths far exceeding those based on chiasma counts. In addition, recombination between specific homoeologous chromosomes derived from interspecific hybrids is sometimes much higher than can be explained by meiotic chiasma frequencies. However, almost the entire discrepancy disappears when proper care is taken of map inflation resulting from the shortcomings of the mapping algorithm and classification errors, the use of dissimilar material, and the difficulty of accurately counting chiasmata. Still, some exchanges, especially of short interstitial segments, cannot readily be explained by normal meiotic behaviour. Aberrant meiotic processes involving segment replacement or insertion can probably be excluded. Some cases of unusual recombination are somatic, possibly premeiotic exchange. For other cases, local relaxation of chiasma interference caused by small interruptions of homology disturbing synaptonemal complex formation is proposed as the cause. It would be accompanied by a preference for compensating exchanges (negative chromatid interference) resulting from asymmetry of the pairing chromatid pairs, so that one side of each pair preferentially participates in pairing. Over longer distances, the pairing face may switch, causing the normal random chromatid participation in double exchanges and the relatively low frequency of short interstitial exchanges. Key words : recombination frequency, map length, chiasmata, discrepancy, chromatid interference.

  10. Haemostatic effects of recombinant coagulation factor VIIa

    NARCIS (Netherlands)

    Lisman, Johannes Antonius

    2002-01-01

    Recombinant coagulation factor VIIa (rFVIIa) has recently become available for treatment of patients with inhibitor-complicated haemophilia. It has been postulated that rFVIIa could become a universal haemostatic agent. Case reports and small studies confirm efficacy and safety of rFVIIa in a

  11. Purification of human recombinant granulocyte colony stimulating ...

    African Journals Online (AJOL)

    In Escherichia coli, recombinant proteins were produced either as three dimensionally folded forms or as unfolded forms, inclusion body (IB). The formation of IB was a frequent consequence of high-level protein production and inadequacy of folding agents namely chaperones in the cytoplasm. The structure of the protein in ...

  12. Recombination modulates how selection affects linked sites in Drosophila.

    Directory of Open Access Journals (Sweden)

    Suzanne E McGaugh

    Full Text Available One of the most influential observations in molecular evolution has been a strong association between local recombination rate and nucleotide polymorphisms across the genome. This is interpreted as evidence for ubiquitous natural selection. The alternative explanation, that recombination is mutagenic, has been rejected by the absence of a similar association between local recombination rate and nucleotide divergence between species. However, many recent studies show that recombination rates are often very different even in closely related species, questioning whether an association between recombination rate and divergence between species has been tested satisfactorily. To circumvent this problem, we directly surveyed recombination across approximately 43% of the D. pseudoobscura physical genome in two separate recombination maps and 31% of the D. miranda physical genome, and we identified both global and local differences in recombination rate between these two closely related species. Using only regions with conserved recombination rates between and within species and accounting for multiple covariates, our data support the conclusion that recombination is positively related to diversity because recombination modulates Hill-Robertson effects in the genome and not because recombination is predominately mutagenic. Finally, we find evidence for dips in diversity around nonsynonymous substitutions. We infer that at least some of this reduction in diversity resulted from selective sweeps and examine these dips in the context of recombination rate.

  13. Complex interactions between new loci, Sluc1, Sluc2, Sluc3 and Sluc4, that influence the susceptibility to lung cancer in the mouse

    NARCIS (Netherlands)

    Fijneman, R.J.A.; Vries, de S.S.; Jansen, R.C.; Demant, P.

    1996-01-01

    Many complex traits, including susceptibility to lung cancer, are controlled by multiple genes - quantitative trait loci (QTLs). We facilitated the mapping of QTLs by making use of recombinant congenic strains (RCS), a system of mouse inbred strains in which the genetic complexity is reduced, and by

  14. Complex interactions of new quantitative trait loci, Sluc1, Sluc2, Sluc3, and Sluc4, that influence the susceptibility to lung cancer in the mouse

    NARCIS (Netherlands)

    Fijneman, Remond J.A.; Vries, Sandra S. de; Jansen, Ritsert C.; Demant, Peter

    1996-01-01

    Many complex traits, including susceptibility to lung cancer, are controlled by multiple genes - quantitative trait loci (QTLs). We facilitated the mapping of QTLs by making use of recombinant congenic strains (RCS), a system of mouse inbred strains in which the genetic complexity is reduced, and by

  15. A molecular recombination map of Antirrhinum majus

    Directory of Open Access Journals (Sweden)

    Hudson Andrew

    2010-12-01

    Full Text Available Abstract Background Genetic recombination maps provide important frameworks for comparative genomics, identifying gene functions, assembling genome sequences and for breeding. The molecular recombination map currently available for the model eudicot Antirrhinum majus is the result of a cross with Antirrhinum molle, limiting its usefulness within A. majus. Results We created a molecular linkage map of A. majus based on segregation of markers in the F2 population of two inbred lab strains of A. majus. The resulting map consisted of over 300 markers in eight linkage groups, which could be aligned with a classical recombination map and the A. majus karyotype. The distribution of recombination frequencies and distorted transmission of parental alleles differed from those of a previous inter-species hybrid. The differences varied in magnitude and direction between chromosomes, suggesting that they had multiple causes. The map, which covered an estimated of 95% of the genome with an average interval of 2 cM, was used to analyze the distribution of a newly discovered family of MITE transposons and tested for its utility in positioning seven mutations that affect aspects of plant size. Conclusions The current map has an estimated interval of 1.28 Mb between markers. It shows a lower level of transmission ratio distortion and a longer length than the previous inter-species map, making it potentially more useful. The molecular recombination map further indicates that the IDLE MITE transposons are distributed throughout the genome and are relatively stable. The map proved effective in mapping classical morphological mutations of A. majus.

  16. Uroporphyrinogen-III synthase: Molecular cloning, nucleotide sequence, expression of a mouse full-length cDNA, and its localization on mouse chromosome 7

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.; Desnick, R.J. [Mount Sinai School of Medicine, New York, NY (United States); Kozak, C.A. [National Institute of Health, Bethesda, MD (United States)

    1995-04-10

    Uroporphyrinogen-III synthase, the fourth enzyme in the heme biosynthetic pathway, is responsible for the conversion of hydroxymethylbilane to the cyclic tetrapyrrole, uroporphyrinogen III. The deficient activity of URO-S is the enzymatic defect in congenital erythropoietic porphyria (CEP), an autosomal recessive disorder. For the generation of a mouse model of CEP, the human URO-S cDNA was used to screen 2 X 10{sup 6} recombinants from a mouse adult liver cDNA library. Ten positive clones were isolated, and dideoxy sequencing of the entire 1.6-kb insert of clone pmUROS-1 revealed 5{prime} and 3{prime} untranslated sequences of 144 and 623 bp, respectively, and an open reading frame of 798 bp encoding a 265-amino-acid polypeptide with a predicted molecular mass of 28,501 Da. The mouse and human coding sequences had 80.5 and 77.8% nucleotide and amino acid identity, respectively. The authenticity of the mouse cDNA was established by expression of the active monomeric enzyme in Escherichia coli. In addition, the analysis of two multilocus genetic crosses localized the mouse gene on chromosome 7, consistent with the mapping of the human gene to a position of conserved synteny on chromosome 10. The isolation, expression, and chromosomal mapping of this full-length cDNA should facilitate studies of the structure and organization of the mouse genomic sequence and the development of a mouse model of CEP for characterization of the disease pathogenesis and evaluation of gene therapy. 38 refs., 1 tab.

  17. Extrachromosomal recombination substrates recapitulate beyond 12/23 restricted VDJ recombination in nonlymphoid cells.

    Science.gov (United States)

    Jung, David; Bassing, Craig H; Fugmann, Sebastian D; Cheng, Hwei-Ling; Schatz, David G; Alt, Frederick W

    2003-01-01

    V(D)J recombination occurs efficiently only between gene segments flanked by recombination signals (RSs) containing 12 and 23 base pair spacers (the 12/23 rule). A further limitation "beyond the 12/23 rule" (B12/23) exists at the TCRbeta locus and ensures Dbeta usage. Herein, we show that extrachromosomal V(D)J recombination substrates recapitulate B12/23 restriction in nonlymphoid cells. We further demonstrate that the Vbeta coding flank, the 12-RS heptamer/nonamer, and the 23-RS spacer each can significantly influence B12/23 restriction. Finally, purified core RAG1 and RAG2 proteins (together with HMG2) also reproduce B12/23 restriction in a cell-free system. Our findings indicate that B12/23 restriction of V(D)J recombination is cemented at the level of interactions between the RAG proteins and TCRbeta RS sequences.

  18. Metabolite profiling of recombinant CHO cells: designing tailored feeding regimes that enhance recombinant antibody production.

    NARCIS (Netherlands)

    Sellick, C.A.; Croxford, A.S.; Maqsood, A.R.; Stephens, G.; Westerhoff, H.V.; Goodacre, R.; Dickson, A.J.

    2011-01-01

    Chinese hamster ovary (CHO) cells are the primary platform for commercial expression of recombinant therapeutic proteins. Obtaining maximum production from the expression platform requires optimal cell culture medium (and associated nutrient feeds). We have used metabolite profiling to define the

  19. Metabolite profiling of recombinant CHO cells: Designing tailored feeding regimes that enhance recombinant antibody production.

    NARCIS (Netherlands)

    Sellick, C.A.; Croxford, A.S.; Maqsood, A.R.; Stephens, G.; Westerhoff, H.V.; Goodacre, R.; Dickson, A.J.

    2011-01-01

    Chinese hamster ovary (CHO) cells are the primary platform for commercial expression of recombinant therapeutic proteins. Obtaining maximum production from the expression platform requires optimal cell culture medium (and associated nutrient feeds). We have used metabolite profiling to define the

  20. Reactivity of mouse antibodies against bromelain-treated mouse erythrocytes with thrombin-treated mouse platelets.

    Science.gov (United States)

    Kawaguchi, S

    1989-01-01

    The reactivity of mouse antibodies against bromelain-treated mouse erythrocytes (BrMRBC) with mouse platelets before and after thrombin treatment was assessed by flow cytometry. Anti-BrMRBC antibodies could bind to thrombin-treated platelets, although normal platelets were also weakly reactive with the antibodies. The binding of anti-BrMRBC antibodies to platelets was confirmed by complement-dependent lysis. It is suggested that thrombin-activated platelets may be a real target for anti-BrMRBC antibodies. PMID:2467876

  1. Hand gestures mouse cursor control

    Directory of Open Access Journals (Sweden)

    Marian-Avram Vincze

    2014-05-01

    Full Text Available The paper describes the implementation of a human-computer interface for controlling the mouse cursor. The test reveal the fact: a low-cost web camera some processing algorithms are quite enough to control the mouse cursor on computers. Even if the system is influenced by the illuminance level on the plane of the hand, the current study may represent a start point for some studies on the hand tracking and gesture recognition field.

  2. Branching innovation, recombinant innovation, and endogenous technological transitions

    NARCIS (Netherlands)

    Frenken, K.|info:eu-repo/dai/nl/207145253; Izquierdo, L.; Zeppini, P.

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create "short-cuts" which reduce

  3. Caenorhabditis briggsae recombinant inbred line genotypes reveal inter-strain incompatibility and the evolution of recombination.

    Directory of Open Access Journals (Sweden)

    Joseph A Ross

    2011-07-01

    Full Text Available The nematode Caenorhabditis briggsae is an emerging model organism that allows evolutionary comparisons with C. elegans and exploration of its own unique biological attributes. To produce a high-resolution C. briggsae recombination map, recombinant inbred lines were generated from reciprocal crosses between two strains and genotyped at over 1,000 loci. A second set of recombinant inbred lines involving a third strain was also genotyped at lower resolution. The resulting recombination maps exhibit discrete domains of high and low recombination, as in C. elegans, indicating these are a general feature of Caenorhabditis species. The proportion of a chromosome's physical size occupied by the central, low-recombination domain is highly correlated between species. However, the C. briggsae intra-species comparison reveals striking variation in the distribution of recombination between domains. Hybrid lines made with the more divergent pair of strains also exhibit pervasive marker transmission ratio distortion, evidence of selection acting on hybrid genotypes. The strongest effect, on chromosome III, is explained by a developmental delay phenotype exhibited by some hybrid F2 animals. In addition, on chromosomes IV and V, cross direction-specific biases towards one parental genotype suggest the existence of cytonuclear epistatic interactions. These interactions are discussed in relation to surprising mitochondrial genome polymorphism in C. briggsae, evidence that the two strains diverged in allopatry, the potential for local adaptation, and the evolution of Dobzhansky-Muller incompatibilities. The genetic and genomic resources resulting from this work will support future efforts to understand inter-strain divergence as well as facilitate studies of gene function, natural variation, and the evolution of recombination in Caenorhabditis nematodes.

  4. Integration and Fixation Preferences of Human and Mouse Endogenous Retroviruses Uncovered with Functional Data Analysis.

    Science.gov (United States)

    Campos-Sánchez, Rebeca; Cremona, Marzia A; Pini, Alessia; Chiaromonte, Francesca; Makova, Kateryna D

    2016-06-01

    Endogenous retroviruses (ERVs), the remnants of retroviral infections in the germ line, occupy ~8% and ~10% of the human and mouse genomes, respectively, and affect their structure, evolution, and function. Yet we still have a limited understanding of how the genomic landscape influences integration and fixation of ERVs. Here we conducted a genome-wide study of the most recently active ERVs in the human and mouse genome. We investigated 826 fixed and 1,065 in vitro HERV-Ks in human, and 1,624 fixed and 242 polymorphic ETns, as well as 3,964 fixed and 1,986 polymorphic IAPs, in mouse. We quantitated >40 human and mouse genomic features (e.g., non-B DNA structure, recombination rates, and histone modifications) in ±32 kb of these ERVs' integration sites and in control regions, and analyzed them using Functional Data Analysis (FDA) methodology. In one of the first applications of FDA in genomics, we identified genomic scales and locations at which these features display their influence, and how they work in concert, to provide signals essential for integration and fixation of ERVs. The investigation of ERVs of different evolutionary ages (young in vitro and polymorphic ERVs, older fixed ERVs) allowed us to disentangle integration vs. fixation preferences. As a result of these analyses, we built a comprehensive model explaining the uneven distribution of ERVs along the genome. We found that ERVs integrate in late-replicating AT-rich regions with abundant microsatellites, mirror repeats, and repressive histone marks. Regions favoring fixation are depleted of genes and evolutionarily conserved elements, and have low recombination rates, reflecting the effects of purifying selection and ectopic recombination removing ERVs from the genome. In addition to providing these biological insights, our study demonstrates the power of exploiting multiple scales and localization with FDA. These powerful techniques are expected to be applicable to many other genomic investigations.

  5. Different levels of immunogenicity of two strains of Fowlpox virus as recombinant vaccine vectors eliciting T-cell responses in heterologous prime-boost vaccination strategies.

    Science.gov (United States)

    Cottingham, Matthew G; van Maurik, Andre; Zago, Manola; Newton, Angela T; Anderson, Richard J; Howard, M Keith; Schneider, Jörg; Skinner, Michael A

    2006-07-01

    The FP9 strain of F has been described as a more immunogenic recombinant vaccine vector than the Webster FPV-M (FPW) strain (R. J. Anderson et al., J. Immunol. 172:3094-3100, 2004). This study expands the comparison to include two separate recombinant antigens and multiple, rather than single, independent viral clones derived from the two strains. Dual-poxvirus heterologous prime-boost vaccination regimens using individual clones of recombinant FP9 or FPW in combination with recombinant modified V Ankara expressing the same antigen were evaluated for their ability to elicit T-cell responses against recombinant antigens from Plasmodium berghei (circumsporozoite protein) or human immunodeficiency virus type 1 (a Gag-Pol-Nef fusion protein). Gamma interferon enzyme-linked immunospot assay and fluorescence-activated cell sorting assays of the responses to specific epitopes confirmed the approximately twofold-greater cellular immunogenicity of FP9 compared to FPW, when given as the priming or boosting immunization. Equality of transgene expression in mouse cells infected with the two strains in vitro was verified by Western blotting. Directed partial sequence analysis and PCR analysis of FPW and comparison to available whole-genome sequences revealed that many loci that are mutated in the highly attenuated and culture-adapted FP9 strain are wild type in FPW, including the seven multikilobase deletions. These "passage-specific" alterations are hypothesized to be involved in determining the immunogenicity of fowlpox virus as a recombinant vaccine vector.

  6. Antagonism of the prostaglandin D2 receptor CRTH2 attenuates asthma pathology in mouse eosinophilic airway inflammation

    DEFF Research Database (Denmark)

    Uller, Lena; Mathiesen, Jesper Mosolff; Alenmyr, Lisa

    2007-01-01

    in recombinant expression systems in vitro. In vivo effects of TM30089 and ramatroban on tissue eosinophilia and mucus cell histopathology were examined in a mouse asthma model. RESULTS: TM30089, displayed high selectivity for and antagonistic potency on mouse CRTH2 but lacked affinity to TP and many other...... receptors including the related anaphylatoxin C3a and C5a receptors, selected chemokine receptors and the cyclooxygenase isoforms 1 and 2 which are all recognized players in allergic diseases. Furthermore, TM30089 and ramatroban, the latter used as a reference herein, similarly inhibited asthma pathology...

  7. Influence of grain size and grain boundary recombination velocity on ...

    African Journals Online (AJOL)

    The plot of the diffusion capacitance allowed us to study the influence of the following parameters: grain size, grain boundary recombination velocity, junction recombination velocity and illumination wavelength on this capacitance. This study pointed out that junction and grain boundary recombination velocities play an ...

  8. Genetic Analysis of Meiotic Recombination in Schizosaccharomyces pombe

    OpenAIRE

    Smith, Gerald R.

    2009-01-01

    The fission yeast Schizosaccharomyces pombe is well-suited for studying meiotic recombination. Methods are described here for culturing S. pombe and for genetic assays of intragenic recombination (gene conversion), intergenic recombination (crossing-over), and spore viability. Both random spore and tetrad analyses are described.

  9. Genetic analysis of japonica x indica recombinant inbred lines and ...

    African Journals Online (AJOL)

    Genetic analysis of japonica x indica recombinant inbred lines and characterization of major fragrance gene by microsatellite markers. ... At some SSR loci, new/recombinant alleles were observed, which indicate the active recombination between genomes of two rice varieties and can be used for linkage mapping once ...

  10. Regulation of homologous recombination at telomeres in budding yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine; Lisby, Michael

    2010-01-01

    Homologous recombination is suppressed at normal length telomere sequences. In contrast, telomere recombination is allowed when telomeres erode in the absence of telomerase activity or as a consequence of nucleolytic degradation or incomplete replication. Here, we review the mechanisms...... that contribute to regulating mitotic homologous recombination at telomeres and the role of these mechanisms in signalling short telomeres in the budding yeast Saccharomyces cerevisiae....

  11. Dispersive and steady-state recombination in organic disordered semiconductors

    Science.gov (United States)

    Hofacker, Andreas; Neher, Dieter

    2017-12-01

    Charge carrier recombination in organic disordered semiconductors is strongly influenced by the thermalization of charge carriers in the density of states (DOS). Measurements of recombination dynamics, conducted under transient or steady-state conditions, can easily be misinterpreted when a detailed understanding of the interplay of thermalization and recombination is missing. To enable adequate measurement analysis, we solve the multiple-trapping problem for recombining charge carriers and analyze it in the transient and steady excitation paradigm for different DOS distributions. We show that recombination rates measured after pulsed excitation are inherently time dependent since recombination gradually slows down as carriers relax in the DOS. When measuring the recombination order after pulsed excitation, this leads to an apparent high-order recombination at short times. As times goes on, the recombination order approaches an asymptotic value. For the Gaussian and the exponential DOS distributions, this asymptotic value equals the recombination order of the equilibrated system under steady excitation. For a more general DOS distribution, the recombination order can also depend on the carrier density, under both transient and steady-state conditions. We conclude that transient experiments can provide rich information about recombination in and out of equilibrium and the underlying DOS occupation provided that consistent modeling of the system is performed.

  12. Experimental risk assessment of recombinant Newcastle disease virus vaccines

    Science.gov (United States)

    Recombinant Newcastle disease viruses (NDV) used as live vaccines were assessed for: 1) the potential for recombinant NDV-vectored vaccines (rNDV) containing the Avian Influenza virus (AIV) H5 gene to recombine with low pathogenicity H5, H6 and H9 AIV strains, and originate a virus with increased vi...

  13. Anti-proliferative activity of recombinant melittin expressed in ...

    African Journals Online (AJOL)

    Recombinant melittin was then successfully expressed in Escherichia coli. The activity of affinity-purified recombinant melittin was determined in human leukemic U937 cells. Results show that the recombinant melittin had the same anti-proliferative activity in human leukemic U937 cells in vitro as natural one. This shows the ...

  14. A Structural and Functional Comparison Between Infectious and Non-Infectious Autocatalytic Recombinant PrP Conformers.

    Directory of Open Access Journals (Sweden)

    Geoffrey P Noble

    2015-06-01

    Full Text Available Infectious prions contain a self-propagating, misfolded conformer of the prion protein termed PrPSc. A critical prediction of the protein-only hypothesis is that autocatalytic PrPSc molecules should be infectious. However, some autocatalytic recombinant PrPSc molecules have low or undetectable levels of specific infectivity in bioassays, and the essential determinants of recombinant prion infectivity remain obscure. To identify structural and functional features specifically associated with infectivity, we compared the properties of two autocatalytic recombinant PrP conformers derived from the same original template, which differ by >105-fold in specific infectivity for wild-type mice. Structurally, hydrogen/deuterium exchange mass spectrometry (DXMS studies revealed that solvent accessibility profiles of infectious and non-infectious autocatalytic recombinant PrP conformers are remarkably similar throughout their protease-resistant cores, except for two domains encompassing residues 91-115 and 144-163. Raman spectroscopy and immunoprecipitation studies confirm that these domains adopt distinct conformations within infectious versus non-infectious autocatalytic recombinant PrP conformers. Functionally, in vitro prion propagation experiments show that the non-infectious conformer is unable to seed mouse PrPC substrates containing a glycosylphosphatidylinositol (GPI anchor, including native PrPC. Taken together, these results indicate that having a conformation that can be specifically adopted by post-translationally modified PrPC molecules is an essential determinant of biological infectivity for recombinant prions, and suggest that this ability is associated with discrete features of PrPSc structure.

  15. A Structural and Functional Comparison Between Infectious and Non-Infectious Autocatalytic Recombinant PrP Conformers

    Science.gov (United States)

    Noble, Geoffrey P.; Wang, Daphne W.; Walsh, Daniel J.; Barone, Justin R.; Miller, Michael B.; Nishina, Koren A.; Li, Sheng; Supattapone, Surachai

    2015-01-01

    Infectious prions contain a self-propagating, misfolded conformer of the prion protein termed PrPSc. A critical prediction of the protein-only hypothesis is that autocatalytic PrPSc molecules should be infectious. However, some autocatalytic recombinant PrPSc molecules have low or undetectable levels of specific infectivity in bioassays, and the essential determinants of recombinant prion infectivity remain obscure. To identify structural and functional features specifically associated with infectivity, we compared the properties of two autocatalytic recombinant PrP conformers derived from the same original template, which differ by >105-fold in specific infectivity for wild-type mice. Structurally, hydrogen/deuterium exchange mass spectrometry (DXMS) studies revealed that solvent accessibility profiles of infectious and non-infectious autocatalytic recombinant PrP conformers are remarkably similar throughout their protease-resistant cores, except for two domains encompassing residues 91-115 and 144-163. Raman spectroscopy and immunoprecipitation studies confirm that these domains adopt distinct conformations within infectious versus non-infectious autocatalytic recombinant PrP conformers. Functionally, in vitro prion propagation experiments show that the non-infectious conformer is unable to seed mouse PrPC substrates containing a glycosylphosphatidylinositol (GPI) anchor, including native PrPC. Taken together, these results indicate that having a conformation that can be specifically adopted by post-translationally modified PrPC molecules is an essential determinant of biological infectivity for recombinant prions, and suggest that this ability is associated with discrete features of PrPSc structure. PMID:26125623

  16. A new Defective Helper RNA to produce recombinant Sindbis virus that infects neurons but does not propagate

    Directory of Open Access Journals (Sweden)

    Justus M Kebschull

    2016-05-01

    Full Text Available Recombinant Sindbis viruses are important tools in neuroscience because they combine rapid and high transgene expression with a capacity to carry large transgenes. Currently, two packaging systems based on the DH(26S5’SIN and the DH-BB(tRNA;TE12 Defective Helper (DH RNAs are available for generating recombinant Sindbis virus that is neurotropic (able to infect neurons and potentially other cells. Both systems produce a fraction of viral particles that can propagate beyond the primary infected neuron. When injected into mouse brain, viruses produced using these DH RNAs produce transgene expression at the injection site, but also elsewhere in the brain. Such ectopic labeling caused recombinant Sindbis viruses to be classified as anterograde viruses with limited retrograde spread, and can complicate the interpretation of neuroanatomical and other experiments.Here we describe a new DH RNA, DH-BB(5’SIN;TE12ORF, that can be used to produce virus that is both neurotropic and propagation-incompetent. We show in mice that DH-BB(5’SIN;TE12ORF-packaged virus eliminates infection of cells outside the injection site. We also provide evidence that ectopically labeled cells observed in previous experiments with recombinant Sindbis virus resulted from secondary infection by propagation-competent virus, rather than from inefficient retrograde spread. Virus produced with our new packaging system retains all the advantages of previous recombinant Sindbis viruses, but minimizes the risks of confounding results with unwanted ectopic labeling. It should therefore be considered in future studies in which a neurotropic, recombinant Sindbis virus is needed.

  17. Rosa26-GFP direct repeat (RaDR-GFP mice reveal tissue- and age-dependence of homologous recombination in mammals in vivo.

    Directory of Open Access Journals (Sweden)

    Michelle R Sukup-Jackson

    2014-06-01

    Full Text Available Homologous recombination (HR is critical for the repair of double strand breaks and broken replication forks. Although HR is mostly error free, inherent or environmental conditions that either suppress or induce HR cause genomic instability. Despite its importance in carcinogenesis, due to limitations in our ability to detect HR in vivo, little is known about HR in mammalian tissues. Here, we describe a mouse model in which a direct repeat HR substrate is targeted to the ubiquitously expressed Rosa26 locus. In the Rosa26 Direct Repeat-GFP (RaDR-GFP mice, HR between two truncated EGFP expression cassettes can yield a fluorescent signal. In-house image analysis software provides a rapid method for quantifying recombination events within intact tissues, and the frequency of recombinant cells can be evaluated by flow cytometry. A comparison among 11 tissues shows that the frequency of recombinant cells varies by more than two orders of magnitude among tissues, wherein HR in the brain is the lowest. Additionally, de novo recombination events accumulate with age in the colon, showing that this mouse model can be used to study the impact of chronic exposures on genomic stability. Exposure to N-methyl-N-nitrosourea, an alkylating agent similar to the cancer chemotherapeutic temozolomide, shows that the colon, liver and pancreas are susceptible to DNA damage-induced HR. Finally, histological analysis of the underlying cell types reveals that pancreatic acinar cells and liver hepatocytes undergo HR and also that HR can be specifically detected in colonic somatic stem cells. Taken together, the RaDR-GFP mouse model provides new understanding of how tissue and age impact susceptibility to HR, and enables future studies of genetic, environmental and physiological factors that modulate HR in mammals.

  18. An ectopic CTCF-dependent transcriptional insulator influences the choice of Vβ gene segments for VDJ recombination at TCRβ locus.

    Science.gov (United States)

    Shrimali, Sweety; Srivastava, Surabhi; Varma, Garima; Grinberg, Alex; Pfeifer, Karl; Srivastava, Madhulika

    2012-09-01

    Insulators regulate transcription as they modulate the interactions between enhancers and promoters by organizing the chromatin into distinct domains. To gain better understanding of the nature of chromatin domains defined by insulators, we analyzed the ability of an insulator to interfere in VDJ recombination, a process that is critically dependent on long-range interactions between diverse types of cis-acting DNA elements. A well-established CTCF-dependent transcriptional insulator, H19 imprint control region (H19-ICR), was inserted in the mouse TCRβ locus by genetic manipulation. Analysis of the mutant mice demonstrated that the insulator retains its CTCF and position-dependent enhancer-blocking potential in this heterologous context in vivo. Remarkably, the inserted H19-ICR appears to have the ability to modulate cis-DNA interactions between recombination signal sequence elements of the TCRβ locus leading to a dramatically altered usage of Vβ segments for Vβ-to-DβJβ recombination in the mutant mice. This reveals a novel ability of CTCF to govern long range cis-DNA interactions other than enhancer-promoter interactions and suggests that CTCF-dependent insulators may play a diverse and complex role in genome organization beyond transcriptional control. Our functional analysis of mutated TCRβ locus supports the emerging role of CTCF in governing VDJ recombination.

  19. An ectopic CTCF-dependent transcriptional insulator influences the choice of Vβ gene segments for VDJ recombination at TCRβ locus

    Science.gov (United States)

    Shrimali, Sweety; Srivastava, Surabhi; Varma, Garima; Grinberg, Alex; Pfeifer, Karl; Srivastava, Madhulika

    2012-01-01

    Insulators regulate transcription as they modulate the interactions between enhancers and promoters by organizing the chromatin into distinct domains. To gain better understanding of the nature of chromatin domains defined by insulators, we analyzed the ability of an insulator to interfere in VDJ recombination, a process that is critically dependent on long-range interactions between diverse types of cis-acting DNA elements. A well-established CTCF-dependent transcriptional insulator, H19 imprint control region (H19-ICR), was inserted in the mouse TCRβ locus by genetic manipulation. Analysis of the mutant mice demonstrated that the insulator retains its CTCF and position-dependent enhancer-blocking potential in this heterologous context in vivo. Remarkably, the inserted H19-ICR appears to have the ability to modulate cis-DNA interactions between recombination signal sequence elements of the TCRβ locus leading to a dramatically altered usage of Vβ segments for Vβ-to-DβJβ recombination in the mutant mice. This reveals a novel ability of CTCF to govern long range cis-DNA interactions other than enhancer–promoter interactions and suggests that CTCF-dependent insulators may play a diverse and complex role in genome organization beyond transcriptional control. Our functional analysis of mutated TCRβ locus supports the emerging role of CTCF in governing VDJ recombination. PMID:22718969

  20. Germ-line recombination activity of the widely used hGFAP-Cre and nestin-Cre transgenes.

    Directory of Open Access Journals (Sweden)

    Jiong Zhang

    Full Text Available Herein we demonstrate with PCR, immunodetection and reporter gene approaches that the widely used human Glial Fibrillary Acidic Protein (hGFAP-Cre transgene exhibits spontaneous germ-line recombination activity in leading to deletion in brain, heart and tail tissue with high frequency. The ectopic activity of hGFAP-Cre requires a rigorous control. We likewise observed that a second widely used nestin-Cre transgene shows germ-line deletion. Here we describe procedures to identify mice with germ-line recombination mediated by the hGFAP-Cre and nestin-Cre transgenes. Such control is essential to avoid pleiotropic effects due to germ-line deletion of loxP-flanked target genes and to maintain the CNS-restricted deletion status in transgenic mouse colonies.

  1. Cloning, expression and evaluation of the efficacy of a recombinant Baylisascaris schroederi Bs-Ag3 antigen in mice.

    Science.gov (United States)

    Wang, Tao; He, Guangzhi; Yang, Guangyou; Fei, Yuxiang; Zhang, Zhihe; Wang, Chengdong; Yang, Zhi; Lan, Jingchao; Luo, Li; Liu, Li

    2008-12-09

    The gene Bs-Ag3 enconding a antigen of 37kDa from Baylisascaris schroederi (giant panda isolates), as well as the recombinant Bs-Ag3, obtained by cloning and expression of the Bs-Ag3 gene in heterologous host Escherichia coli BL-21 (DE3), were used to evaluate their ability to induce immune protective responses in BALB/c mice against L3-challenge infection in a mouse-B. schroederi model. There was a significant reduction (62.91%) of mice vaccinated with rBs-Ag3 coupled with Freund's complete adjuvant (FCA) in recovery of challenged B. schroederi L3 compared with either controls or mice vaccinated with FCA alone. Our data indicate recombinant Bs-Ag3 may be a potential target as a vaccine antigen for giant panda ascariasis.

  2. Failure of a vaccine using immunogenic recombinant proteins rNcSAG4 and rNcGRA7 against neosporosis in mice.

    Science.gov (United States)

    Aguado-Martínez, Adriana; Alvarez-García, Gema; Fernández-García, Aurora; Risco-Castillo, Verónica; Marugán-Hernández, Virginia; Ortega-Mora, Luis M

    2009-12-09

    The development of an effective vaccine against Neospora caninum infection in cattle is an important issue due to the significant economic impact of this parasitic disease worldwide. In this work, the immune response, safety and efficacy of different vaccine formulations using the N. caninum recombinant proteins rNcSAG4 (the first bradyzoite-specific protein assayed as a vaccine) and rNcGRA7 were evaluated in mouse models. The survival curves of pups from all vaccinated groups showed a slight delay in time to death compared to control groups; this difference was statistically significant for rNcSAG4+adjuvant group. Immune response of mice vaccinated with rNcSAG4 was characterized by reduced specific IgG and cytokine levels with an equilibrated IFN-gamma/IL-10 balance. Regarding mice vaccinated with rNcGRA7, a very strong humoral and cellular immune response was generated characterized by a hyper-production of IFN-gamma. This response was not accompanied by significant protection. Vaccination with a mixture of both recombinant proteins reduced infection in lung and brain during acute and chronic infection, respectively, although it was not statistically significant. In summary, no significant protection was obtained with these vaccine formulations in the present mouse models. However, the study reveals some positive results on immune response and efficacy for both recombinant proteins; these results are being discussed in order to suggest new approaches with new chronic infection mouse models and adjuvants.

  3. Bacterial Artificial Chromosome Mutagenesis Using Recombineering

    Directory of Open Access Journals (Sweden)

    Kumaran Narayanan

    2011-01-01

    Full Text Available Gene expression from bacterial artificial chromosome (BAC clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough to transfer intact genes in their native chromosomal setting together with flanking regulatory elements to provide all the signals for correct spatiotemporal gene expression. Until recently, the use of BACs for functional studies has been limited because their large size has inherently presented a major obstacle for introducing modifications using conventional genetic engineering strategies. The development of in vivo homologous recombination strategies based on recombineering in E. coli has helped resolve this problem by enabling facile engineering of high molecular weight BAC DNA without dependence on suitably placed restriction enzymes or cloning steps. These techniques have considerably expanded the possibilities for studying functional genetics using BACs in vitro and in vivo.

  4. Multiple Exponential Recombination for Differential Evolution.

    Science.gov (United States)

    Xin Qiu; Kay Chen Tan; Jian-Xin Xu

    2017-04-01

    Differential evolution (DE) is a popular population-based metaheuristic approach for solving numerical optimization problems. In recent years, considerable research has been devoted to the development of new mutation strategies and parameter adaptation mechanisms. However, as one of the basic algorithmic components of DE, the crossover operation has not been sufficiently examined in existing works. Most of the main DE variants solely employ traditional binomial recombination, which has intrinsic limitations in handling dependent subsets of variables. To fill this research niche, we propose a multiple exponential recombination that inherits all the main advantages of existing crossover operators while possessing a stronger ability in managing dependent variables. Multiple segments of the involved solutions will be exchanged during the proposed operator. The properties of the new scheme are examined both theoretically and empirically. Experimental results demonstrate the robustness of the proposed operator in solving problems with unknown variable interrelations.

  5. Fibrinolytic Activity of Recombinant Mutant Streptokinase

    Directory of Open Access Journals (Sweden)

    Mahboobeh Mobarrez

    2015-04-01

    Full Text Available Background: Streptokinase is a bacterial protein produced by different beta hemolytic streptococci and widely used in thrombolytic treatment. The main disadvantage of using streptokinase is antibody formation which causes allergic reaction to neutralize effects of streptokinase therapy. Aim of this study was investigate of recombinant mutant streptokinase fibrinolytic activity.Materials and Methods: In this study recombinant mutant streptokinase without 42 amino acids from the C terminal region was purified by affinity S-Tag column chromatography and its fibrinolytic activity was studied.Results: The concentration of expressed and purified protein was 10 mg/ml. Its enzyme activity was assayed using zymography, radial caseinolytic activity and fibrin plate test methods and estimated quantitatively by casein digestion method compared to a commercial form.Conclusion: It was found that this product had the more volume and more enzymatic activity.

  6. CFD Analysis of Passive Autocatalytic Recombiner

    Directory of Open Access Journals (Sweden)

    B. Gera

    2011-01-01

    Full Text Available In water-cooled nuclear power reactors, significant quantities of hydrogen could be produced following a postulated loss-of-coolant accident (LOCA along with nonavailability of emergency core cooling system (ECCS. Passive autocatalytic recombiners (PAR are implemented in the containment of water-cooled power reactors to mitigate the risk of hydrogen combustion. In the presence of hydrogen with available oxygen, a catalytic reaction occurs spontaneously at the catalyst surfaces below conventional ignition concentration limits and temperature and even in presence of steam. Heat of reaction produces natural convection flow through the enclosure and promotes mixing in the containment. For the assessment of the PAR performance in terms of maximum temperature of catalyst surface and outlet hydrogen concentration an in-house 3D CFD model has been developed. The code has been used to study the mechanism of catalytic recombination and has been tested for two literature-quoted experiments.

  7. DSMC Modeling of Flows with Recombination Reactions

    Science.gov (United States)

    2017-06-23

    Reactions S. Gimelshein, I. Wysong Air Force Research Laboratory (AFMC) AFRL/RQRC 10 E. Saturn Blvd. Edwards AFB, CA 93524-7680 Air Force Research ...dis- sociation and exchange reactions for diatomic , and sometimes for polyatomic, molecules. The recombination reaction was largely avoided in the DSMC...believed to provide adequate accuracy to the VT energy exchange of diatomic molecules. As shown in Fig. 4(a), the use of that model results in good

  8. Calcium chloride improve ethanol production in recombinant ...

    African Journals Online (AJOL)

    The T7-expression fadK genomes were introduced into Z. mobilis ATCC 31821 in order to increase ethanol production. The recombinant bacteria were named as Z.M.F-1, Z.M.F-2, Z.M.F-3, and Z.M.F-4. However, Z.M.F-4 had the highest ability of producing ethanol by selection. Compared with Z. mobilis ATCC 3182, there ...

  9. Dissociation of recombinant prion autocatalysis from infectivity

    OpenAIRE

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication – that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and ...

  10. DCPP1 is the mouse ortholog of human PAUF that possesses functional analogy in pancreatic cancer.

    Science.gov (United States)

    Song, Hayne; Song, Jinhoi; Kim, Yeon Jeong; Jeong, Hyeon Hee; Min, Hye Jin; Koh, Sang Seok

    2017-12-02

    Pancreatic adenocarcinoma upregulated factor (PAUF) overexpressed in pancreatic ductal adenocarcinoma (PDAC) plays a major role in tumor progression and metastasis by autocrine and paracrine manners. However, underlying molecular mechanism of PAUF functioning in pancreatic cancer are not fully understood yet. The objective of this study was to evaluate the potential of demilune cell and parotid protein 1 (DCPP1) as a putative mouse ortholog of human PAUF by sequence alignment and functional studies. Overexpression of mouse DCPP1 in Chinese hamster ovary (CHO) cells or pancreatic cancer cells increased cell proliferation, migration, invasion, and adhesion ability in vitro. Treatment of human pancreatic cancer cells with recombinant mouse DCPP1 elevated cell growth, motility, invasiveness, and adhesiveness. Mouse DCPP1 exerted its function on pancreatic cancer cells by activating intracellular signaling pathways involved in aggressive cancer phenotype of human pancreatic cancer cells. Moreover, subcutaneous injection of mice with DCPP1-overexpressing CHO cells increased tumor sizes. Taken together, we conclude that mouse DCPP1 is a multifunctional promoter of tumor growth through functional activation of pancreatic cancer cells, suggesting it to be an ortholog of human PAUF. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. CFD modeling of passive autocatalytic recombiners*

    Directory of Open Access Journals (Sweden)

    Orszulik Magdalena

    2015-06-01

    Full Text Available This study deals with numerical modeling of passive autocatalytic hydrogen recombiners (PARs. Such devices are installed within containments of many nuclear reactors in order to remove hydrogen and convert it to steam. The main purpose of this work is to develop a numerical model of passive autocatalytic recombiner (PAR using the commercial computational fluid dynamics (CFD software ANSYS-FLUENT and tuning the model using experimental results. The REKO 3 experiment was used for this purpose. Experiment was made in the Institute for Safety Research and Reactor Technology in Julich (Germany. It has been performed for different hydrogen concentrations, different flow rates, the presence of steam, and different initial temperatures of the inlet mixture. The model of this experimental recombiner was elaborated within the framework of this work. The influence of mesh, gas thermal conductivity coefficient, mass diffusivity coefficients, and turbulence model was investigated. The best results with a good agreement with REKO 3 data were received for k-ɛ model of turbulence, gas thermal conductivity dependent on the temperature and mass diffusivity coefficients taken from CHEMKIN program. The validated model of the PAR was next implemented into simple two-dimensional simulations of hydrogen behavior within a subcompartment of a containment building.

  12. Recombinant vaccine for canine parvovirus in dogs.

    Science.gov (United States)

    López de Turiso, J A; Cortés, E; Martínez, C; Ruiz de Ybáñez, R; Simarro, I; Vela, C; Casal, I

    1992-01-01

    VP2 is the major component of canine parvovirus (CPV) capsids. The VP2-coding gene was engineered to be expressed by a recombinant baculovirus under the control of the polyhedrin promoter. A transfer vector that contains the lacZ gene under the control of the p10 promoter was used in order to facilitate the selection of recombinants. The expressed VP2 was found to be structurally and immunologically indistinguishable from authentic VP2. The recombinant VP2 shows also the capability to self-assemble, forming viruslike particles similar in size and appearance to CPV virions. These viruslike particles have been used to immunize dogs in different doses and combinations of adjuvants, and the anti-CPV responses have been measured by enzyme-linked immunosorbent assay, monolayer protection assays, and an assay for the inhibition of hemagglutination. A dose of ca. 10 micrograms of VP2 was able to elicit a good protective response, higher than that obtained with a commercially available, inactivated vaccine. The results indicate that these viruslike particles can be used to protect dogs from CPV infection. Images PMID:1313899

  13. High-Resolution Maps of Mouse Reference Populations

    Directory of Open Access Journals (Sweden)

    Petr Simecek

    2017-10-01

    Full Text Available Genetic reference panels are widely used to map complex, quantitative traits in model organisms. We have generated new high-resolution genetic maps of 259 mouse inbred strains from recombinant inbred strain panels (C57BL/6J × DBA/2J, ILS/IbgTejJ × ISS/IbgTejJ, and C57BL/6J × A/J and chromosome substitution strain panels (C57BL/6J-Chr#, C57BL/6J-Chr#, and C57BL/6J-Chr#. We genotyped all samples using the Affymetrix Mouse Diversity Array with an average intermarker spacing of 4.3 kb. The new genetic maps provide increased precision in the localization of recombination breakpoints compared to the previous maps. Although the strains were presumed to be fully inbred, we found residual heterozygosity in 40% of individual mice from five of the six panels. We also identified de novo deletions and duplications, in homozygous or heterozygous state, ranging in size from 21 kb to 8.4 Mb. Almost two-thirds (46 out of 76 of these deletions overlap exons of protein coding genes and may have phenotypic consequences. Twenty-nine putative gene conversions were identified in the chromosome substitution strains. We find that gene conversions are more likely to occur in regions where the homologous chromosomes are more similar. The raw genotyping data and genetic maps of these strain panels are available at http://churchill-lab.jax.org/website/MDA.

  14. Recombinant cells and organisms having persistent nonstandard amino acid dependence and methods of making them

    Energy Technology Data Exchange (ETDEWEB)

    Church, George M.; Mandell, Daniel J.; Lajoie, Marc J.

    2017-12-05

    Recombinant cells and recombinant organisms persistently expressing nonstandard amino acids (NSAAs) are provided. Methods of making recombinant cells and recombinant organisms dependent on persistently expressing NSAAs for survival are also provided. These methods may be used to make safe recombinant cells and recombinant organisms and/or to provide a selective pressure to maintain one or more reassigned codon functions in recombinant cells and recombinant organisms.

  15. Hybrid mouse diversity panel: a panel of inbred mouse strains suitable for analysis of complex genetic traits

    Science.gov (United States)

    Ghazalpour, Anatole; Rau, Christoph D.; Farber, Charles R.; Bennett, Brian J.; Orozco, Luz D.; van Nas, Atila; Pan, Calvin; Allayee, Hooman; Beaven, Simon W.; Civelek, Mete; Davis, Richard C.; Drake, Thomas A.; Friedman, Rick A.; Furlotte, Nick; Hui, Simon T.; Jentsch, J. David; Kostem, Emrah; Kang, Hyun Min; Kang, Eun Yong; Joo, Jong Wha; Korshunov, Vyacheslav A.; Laughlin, Rick E.; Martin, Lisa J.; Ohmen, Jeffrey D.; Parks, Brian W.; Pellegrini, Matteo; Reue, Karen; Smith, Desmond J.; Tetradis, Sotirios; Wang, Jessica; Wang, Yibin; Weiss, James N.; Kirchgessner, Todd; Gargalovic, Peter S.; Eskin, Eleazar; Lusis, Aldons J.

    2012-01-01

    We have developed an association-based approach using classical inbred strains of mice in which we correct for population structure, which is very extensive in mice, using an efficient mixed-model algorithm. Our approach includes inbred parental strains as well as recombinant inbred strains in order to capture loci with effect sizes typical of complex traits in mice (in the range of 5 % of total trait variance). Over the last few years, we have typed the hybrid mouse diversity panel (HMDP) strains for a variety of clinical traits as well as intermediate phenotypes and have shown that the HMDP has sufficient power to map genes for highly complex traits with resolution that is in most cases less than a megabase. In this essay, we review our experience with the HMDP, describe various ongoing projects, and discuss how the HMDP may fit into the larger picture of common diseases and different approaches. PMID:22892838

  16. Comparative mapping of mouse chromosome 4 and human chromosome 9: Lv, Orm, and Hxb are closely linked on mouse chromosome 4.

    Science.gov (United States)

    Pilz, A; Moseley, H; Peters, J; Abbott, C

    1992-01-01

    The genes for orosomucoid (ORM-1 and ORM-2), delta-aminolevulinate dehydratase (ALAD), and hexabrachion or tenascin (HXB) all map to the q31-qter region of human Chromosome (Chr) 9. The mouse homolog of each of these genes has been mapped to Chr4, but hexabrachion has not previously been mapped by linkage analysis. We have now ordered Orm-1, Lv (the mouse homolog of ALAD), and Hxb in an interspecific backcross panel, by use of tyrosinase related protein-1, Tyrp-1, whose human homolog maps to 9p13-pter (Abbott et al., Genomics 1991) as a reference locus. No recombinants were identified in 124 animals between Lv and Orm-1. Hxb was found to be 1.6 cM distal to Lv and Orm-1, and 4.8 cM proximal to Tyrp-1, or b. These data therefore contribute to our knowledge of the conserved synteny between HSA 9q and MMU 4.

  17. Antagonistic experimental coevolution with a parasite increases host recombination frequency

    Directory of Open Access Journals (Sweden)

    Kerstes Niels AG

    2012-02-01

    Full Text Available Abstract Background One of the big remaining challenges in evolutionary biology is to understand the evolution and maintenance of meiotic recombination. As recombination breaks down successful genotypes, it should be selected for only under very limited conditions. Yet, recombination is very common and phylogenetically widespread. The Red Queen Hypothesis is one of the most prominent hypotheses for the adaptive value of recombination and sexual reproduction. The Red Queen Hypothesis predicts an advantage of recombination for hosts that are coevolving with their parasites. We tested predictions of the hypothesis with experimental coevolution using the red flour beetle, Tribolium castaneum, and its microsporidian parasite, Nosema whitei. Results By measuring recombination directly in the individuals under selection, we found that recombination in the host population was increased after 11 generations of coevolution. Detailed insights into genotypic and phenotypic changes occurring during the coevolution experiment furthermore helped us to reconstruct the coevolutionary dynamics that were associated with this increase in recombination frequency. As coevolved lines maintained higher genetic diversity than control lines, and because there was no evidence for heterozygote advantage or for a plastic response of recombination to infection, the observed increase in recombination most likely represented an adaptive host response under Red Queen dynamics. Conclusions This study provides direct, experimental evidence for an increase in recombination frequency under host-parasite coevolution in an obligatory outcrossing species. Combined with earlier results, the Red Queen process is the most likely explanation for this observation.

  18. Monitoring homologous recombination in rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhuanying; Tang Li [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Li Meiru [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Chen Lei; Xu Jie [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China); Wu Goujiang [South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650 (China); Li Hongqing, E-mail: hqli@scnu.edu.cn [Guangdong Provincial Key Lab of Biotechnology for Plant Development, College of Life Sciences, South China Normal University, Guangzhou 510631 (China)

    2010-09-10

    Here we describe a system to assay homologous recombination during the complete life cycle of rice (Oryza sativa L.). Rice plants were transformed with two copies of non-functional GUS reporter overlap fragments as recombination substrate. Recombination was observed in all plant organs examined, from the seed stage until the flowering stage of somatic plant development. Embryogenic cells exhibited the highest recombination ability with an average of 3 x 10{sup -5} recombination events per genome, which is about 10-fold of that observed in root cells, and two orders of that observed in leaf cells. Histological analysis revealed that recombination events occurred in diverse cell types, but preferentially in cells with small size. Examples of this included embryogenic cells in callus, phloem cells in the leaf vein, and cells located in the root apical meristem. Steady state RNA analysis revealed that the expression levels of rice Rad51 homologs are positively correlated with increased recombination rates in embryogenic calli, roots and anthers. Finally, radiation treatment of plantlets from distinct recombination lines increased the recombination frequency to different extents. These results showed that homologous recombination frequency can be effectively measured in rice using a transgene reporter assay. This system will facilitate the study of DNA damage signaling and homologous recombination in rice, a model monocot.

  19. FASEB Summer Research Conference. Genetic Recombination and Chromosome Rearrangements

    Energy Technology Data Exchange (ETDEWEB)

    Jinks-Robertson, Sue

    2002-02-01

    The 2001 meeting entitled ''Genetic Recombination and Genome Rearrangements'' was held July 21-26 in Snowmass, Colorado. The goal of the meeting was to bring together scientists using diverse approaches to study all aspects of genetic recombination. This goal was achieved by integrating talks covering the genetics, biochemistry and structural biology of homologous recombination, site-specific recombination, and nonhomologous recombination. The format of the meeting consisted of a keynote address on the opening evening, two formal plenary sessions on each of the four full meeting days, a single afternoon workshop consisting of short talks chosen from among submitted abstracts, and afternoon poster sessions on each of the four full meeting days. The eight plenary session were entitled: (1) Recombination Mechanisms, (2) Prokaryotic Recombination, (3) Repair and Recombination, (4) Site-specific Recombination and Transposition, (5) Eukaryotic Recombination I, (6) Genome Rearrangements, (7) Meiosis, and (8) Eukaryotic Recombination II. Each session included a mix of genetic, biochemical and structural talks; talks were limited to 20 minutes, followed by 10 minutes of very lively, general discussion. Much of the data presented in the plenary sessions was unpublished, thus providing attendees with the most up-to-date knowledge of this rapidly-moving field.

  20. Recombination pattern reanalysis of some HIV-1 circulating recombination forms suggest the necessity and difficulty of revision.

    Directory of Open Access Journals (Sweden)

    Lei Jia

    Full Text Available Recombination is one of the major mechanisms underlying the generation of HIV-1 variability. Currently 61 circulating recombinant forms of HIV-1 have been identified. With the development of recombination detection techniques and accumulation of HIV-1 reference stains, more accurate mosaic structures of circulating recombinant forms (CRFs, like CRF04 and CRF06, have undergone repeated analysis and upgrades. Such revisions may also be necessary for other CRFs. Unlike previous studies, whose results are based primarily on a single recombination detection program, the current study was based on multiple recombination analysis, which may have produced more impartial results.Representative references of 3 categories of intersubtype recombinants were selected, including BC recombinants (CRF07 and CRF08, BG recombinants (CRF23 and CRF24, and BF recombinants (CRF38 and CRF44. They were reanalyzed in detail using both the jumping profile hidden Markov model and RDP3.The results indicate that revisions and upgrades are very necessary and the entire re-analysis suggested 2 types of revision: (i length of inserted fragments; and (ii number of inserted fragments. The reanalysis also indicated that determination of small regions of about 200 bases or fewer should be performed with more caution.Results indicated that the involvement of multiple recombination detection programs is very necessary. Additionally, results suggested two major challenges, one involving the difficulty of accurately determining the locations of breakpoints and the second involving identification of small regions of about 200 bases or fewer with greater caution. Both indicate the complexity of HIV-1 recombination. The resolution would depend critically on development of a recombination analysis algorithm, accumulation of HIV-1 stains, and a higher sequencing quality. With the changes in recombination pattern, phylogenetic relationships of some CRFs may also change. All these results may

  1. Mechanisms and factors that influence high frequency retroviral recombination

    DEFF Research Database (Denmark)

    Delviks-Frankenberry, Krista; Galli, Andrea; Nikolaitchik, Olga

    2011-01-01

    With constantly changing environmental selection pressures, retroviruses rely upon recombination to reassort polymorphisms in their genomes and increase genetic diversity, which improves the chances for the survival of their population. Recombination occurs during DNA synthesis, whereby reverse...... transcriptase undergoes template switching events between the two copackaged RNAs, resulting in a viral recombinant with portions of the genetic information from each parental RNA. This review summarizes our current understanding of the factors and mechanisms influencing retroviral recombination, fidelity...... of the recombination process, and evaluates the subsequent viral diversity and fitness of the progeny recombinant. Specifically, the high mutation rates and high recombination frequencies of HIV-1 will be analyzed for their roles in influencing HIV-1 global diversity, as well as HIV-1 diagnosis, drug treatment...

  2. Mobility dependent recombination models for organic solar cells

    Science.gov (United States)

    Wagenpfahl, Alexander

    2017-09-01

    Modern solar cell technologies are driven by the effort to enhance power conversion efficiencies. A main mechanism limiting power conversion efficiencies is charge carrier recombination which is a direct function of the encounter probability of both recombination partners. In inorganic solar cells with rather high charge carrier mobilities, charge carrier recombination is often dominated by energetic states which subsequently trap both recombination partners for recombination. Free charge carriers move fast enough for Coulomb attraction to be irrelevant for the encounter probability. Thus, charge carrier recombination is independent of charge carrier mobilities. In organic semiconductors charge carrier mobilities are much lower. Therefore, electrons and holes have more time react to mutual Coulomb-forces. This results in the strong charge carrier mobility dependencies of the observed charge carrier recombination rates. In 1903 Paul Langevin published a fundamental model to describe the recombination of ions in gas-phase or aqueous solutions, known today as Langevin recombination. During the last decades this model was used to interpret and model recombination in organic semiconductors. However, certain experiments especially with bulk-heterojunction solar cells reveal much lower recombination rates than predicted by Langevin. In search of an explanation, many material and device properties such as morphology and energetic properties have been examined in order to extend the validity of the Langevin model. A key argument for most of these extended models is, that electron and hole must find each other at a mutual spatial location. This encounter may be limited for instance by trapping of charges in trap states, by selective electrodes separating electrons and holes, or simply by the morphology of the involved semiconductors, making it impossible for electrons and holes to recombine at high rates. In this review, we discuss the development of mobility limited

  3. Single-stranded heteroduplex intermediates in λ Red homologous recombination

    Directory of Open Access Journals (Sweden)

    Zhang Youming

    2010-07-01

    Full Text Available Abstract Background The Red proteins of lambda phage mediate probably the simplest and most efficient homologous recombination reactions yet described. However the mechanism of dsDNA recombination remains undefined. Results Here we show that the Red proteins can act via full length single stranded intermediates to establish single stranded heteroduplexes at the replication fork. We created asymmetrically digestible dsDNA substrates by exploiting the fact that Redα exonuclease activity requires a 5' phosphorylated end, or is blocked by phosphothioates. Using these substrates, we found that the most efficient configuration for dsDNA recombination occurred when the strand that can prime Okazaki-like synthesis contained both homology regions on the same ssDNA molecule. Furthermore, we show that Red recombination requires replication of the target molecule. Conclusions Hence we propose a new model for dsDNA recombination, termed 'beta' recombination, based on the formation of ssDNA heteroduplexes at the replication fork. Implications of the model were tested using (i an in situ assay for recombination, which showed that recombination generated mixed wild type and recombinant colonies; and (ii the predicted asymmetries of the homology arms, which showed that recombination is more sensitive to non-homologies attached to 5' than 3' ends. Whereas beta recombination can generate deletions in target BACs of at least 50 kb at about the same efficiency as small deletions, the converse event of insertion is very sensitive to increasing size. Insertions up to 3 kb are most efficiently achieved using beta recombination, however at greater sizes, an alternative Red-mediated mechanism(s appears to be equally efficient. These findings define a new intermediate in homologous recombination, which also has practical implications for recombineering with the Red proteins.

  4. Inhibition of matrix metalloproteins 9 attenuated Candida albicans induced inflammation in mouse cornea.

    Science.gov (United States)

    Dong, C; Yang, M G

    2016-10-31

    Since the severe corneal ulceration of mouse cornea is known to occur with inflammation. As one of imperative matrix metalloproteinase, the potential roles of matrix metalloproteins 9 (MMP9) in corneal ulceration and keratitis are still unveiled caused by fungal invasion. In this study, Candida albicans (CA) inoculated wild-type KM mice cornea was used as a model pathogen in corneal inflammation.  CA invasion significantly stimulated the expression of collagen IV and MMP9 detected by RT-PCR, Real-time PCR and Immunofluorescent staining in mouse cornea as soon as 6 hours post infection, and relatively decreased at 1 day post infection. For examining the role of MMP9 in fungal keratitis, the mice corneas were subconjunctivally injected MMP9 antibody or recombinant MMP9 protein 6 hours prior to CA inoculation, using rabbit IgG as control. Subconjunctival injection of recombinant MMP9 protein prior to CA inoculation enhanced, whereas MMP9 antibody attenuated corneal ulceration and inflammation, examining basement membrane, fungal load, myeloperoxidase (MPO) and proinflammatory cytokines including Macrophage inflammatory protein 2 (MIP2), Interleukin-1β (IL-1β) and Tumor necrosis factor-α (TNF-α). Inhibition of MMP9 could potentially attenuate Candida albicans induced inflammation in mouse cornea.

  5. Mouse models of Fanconi anemia

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Kalindi; D' Andrea, Alan [Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); Niedernhofer, Laura J., E-mail: niedernhoferl@upmc.edu [Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine and Cancer Institute, 5117 Centre Avenue, Hillman Cancer Center, Research Pavilion 2.6, Pittsburgh, PA 15213-1863 (United States)

    2009-07-31

    Fanconi anemia is a rare inherited disease characterized by congenital anomalies, growth retardation, aplastic anemia and an increased risk of acute myeloid leukemia and squamous cell carcinomas. The disease is caused by mutation in genes encoding proteins required for the Fanconi anemia pathway, a response mechanism to replicative stress, including that caused by genotoxins that cause DNA interstrand crosslinks. Defects in the Fanconi anemia pathway lead to genomic instability and apoptosis of proliferating cells. To date, 13 complementation groups of Fanconi anemia were identified. Five of these genes have been deleted or mutated in the mouse, as well as a sixth key regulatory gene, to create mouse models of Fanconi anemia. This review summarizes the phenotype of each of the Fanconi anemia mouse models and highlights how genetic and interventional studies using the strains have yielded novel insight into therapeutic strategies for Fanconi anemia and into how the Fanconi anemia pathway protects against genomic instability.

  6. 10. international mouse genome conference

    Energy Technology Data Exchange (ETDEWEB)

    Meisler, M.H.

    1996-12-31

    Ten years after hosting the First International Mammalian Genome Conference in Paris in 1986, Dr. Jean-Louis Guenet presided over the Tenth Conference at the Pasteur Institute, October 7--10, 1996. The 1986 conference was a satellite to the Human Gene Mapping Workshop and had approximately 50 attendees. The 1996 meeting was attended by 300 scientists from around the world. In the interim, the number of mapped loci in the mouse increased from 1,000 to over 20,000. This report contains a listing of the program and its participants, and two articles that review the meeting and the role of the laboratory mouse in the Human Genome project. More than 200 papers were presented at the conference covering the following topics: International mouse chromosome committee meetings; Mutant generation and identification; Physical and genetic maps; New technology and resources; Chromatin structure and gene regulation; Rate and hamster genetic maps; Informatics and databases; and Quantitative trait analysis.

  7. Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

    Energy Technology Data Exchange (ETDEWEB)

    Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van [The Department of Biochemistry and Molecular Biology and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Melbourne, Victoria 3010 (Australia)], E-mail: i.vandriel@unimelb.edu.au

    2008-09-01

    Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain {approx}60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H{sup +}/K{sup +} ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H{sup +}/K{sup +} ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H{sup +}/K{sup +} ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in {approx}30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H{sup +}/K{sup +} ATPase which underpin the regulation of acid secretion.

  8. Multiple barriers to recombination between divergent HIV-1 variants revealed by a dual-marker recombination assay

    DEFF Research Database (Denmark)

    Nikolaitchik, Olga A; Galli, Andrea; Moore, Michael D

    2011-01-01

    Recombination is a major force for generating human immunodeficiency virus type 1 (HIV-1) diversity and produces numerous recombinants circulating in the human population. We previously established a cell-based system using green fluorescent protein gene (gfp) as a reporter to study the mechanisms...... of HIV-1 recombination. We now report an improved system capable of detecting recombination using authentic viral sequences. Frameshift mutations were introduced into the gag gene so that parental viruses do not express full-length Gag; however, recombination can generate a progeny virus that expresses...... a functional Gag. We demonstrate that this Gag reconstitution assay can be used to detect recombination between two group M HIV-1 variants of the same or of different subtypes. Using both gfp and gag assays, we found that, similar to group M viruses, group O viruses also recombine frequently. When...

  9. Mouse Resource Browser-a database of mouse databases

    NARCIS (Netherlands)

    Zouberakis, Michael; Chandras, Christina; Swertz, Morris; Smedley, Damian; Gruenberger, Michael; Bard, Jonathan; Schughart, Klaus; Rosenthal, Nadia; Hancock, John M.; Schofield, Paul N.; Kollias, George; Aidinis, Vassilis

    2010-01-01

    The laboratory mouse has become the organism of choice for discovering gene function and unravelling pathogenetic mechanisms of human diseases through the application of various functional genomic approaches. The resulting deluge of data has led to the deployment of numerous online resources and the

  10. Genetic Mapping and Functional Studies of a Natural Inhibitor of the Insulin Receptor Tyrosine Kinase: The Mouse Ortholog of Human α2-HS Glycoprotein

    Science.gov (United States)

    Cintrón, Vivian J.; Ko, Minoru S. H.; Chi, Kenneth D.; Gross, Jason P.; Srinivas, Pothur R.; Goustin, Anton Scott

    2000-01-01

    Fetuin/α2-HS glycoprotein (α2-HSG) homologs have been identified in several species including rat, sheep, pig, rabbit, guinea pig, cattle, mouse and human. Multiple physiological roles for these homologs have been suggested, including ability to bind to hydroxyapatite crystals and to specifically inhibit the tyrosine kinase (TK) activity of the insulin receptor (IR). In this study we report the identification, cloning, and characterization of the mouse Ahsg gene and its function as an IR-TK inhibitor. Genomic clones derived from a mouse Svj 129 genomic library were sequenced in order to characterize the intron–exon organization of the mouse Ahsg gene, including an 875 bp subclone containing 154 bp upstream from the transcription start site, the first exon, and part of the first intron. A second genomic subclone harboring a 3.45 kb Bgl II fragment contained exons 2, 3 and 4 in addition to two adjacent elements within the first intron-a repetitive element of the B1 family (92 bp) and a 271 bp tract of (T,C)n * (A,G)n. We have mapped mouse Ahsg at 16 cM adjacent to the Diacylglycerol kinase 3 (Dagk3) gene on chromosome 16 by genotyping interspecific backcross panels between C57BL/6J and Mus spretus. The position is syntenic with human chromosome 3q27, where the human AHSG gene resides. Using recombinant mouse α2-HSG expressed from a recombinant baculovirus, we demonstrate that mouse α2-HSG inhibits insulin–stimulated IR autophosphorylation and IR-TKA in vitro. In addition, mouse α2-HSG (25μg/ml) completely abolishes insulin-induced DNA synthesis in H-35 rat hepatoma cells. Based on the sequence data and functional analysis, we conclude that the mouse Ahsg gene is the true ortholog of the human AHSG gene. PMID:11467416

  11. ATRX dysfunction induces replication defects in primary mouse cells.

    Directory of Open Access Journals (Sweden)

    David Clynes

    Full Text Available The chromatin remodeling protein ATRX, which targets tandem repetitive DNA, has been shown to be required for expression of the alpha globin genes, for proliferation of a variety of cellular progenitors, for chromosome congression and for the maintenance of telomeres. Mutations in ATRX have recently been identified in tumours which maintain their telomeres by a telomerase independent pathway involving homologous recombination thought to be triggered by DNA damage. It is as yet unknown whether there is a central underlying mechanism associated with ATRX dysfunction which can explain the numerous cellular phenomena observed. There is, however, growing evidence for its role in the replication of various repetitive DNA templates which are thought to have a propensity to form secondary structures. Using a mouse knockout model we demonstrate that ATRX plays a direct role in facilitating DNA replication. Ablation of ATRX alone, although leading to a DNA damage response at telomeres, is not sufficient to trigger the alternative lengthening of telomere pathway in mouse embryonic stem cells.

  12. ATRX dysfunction induces replication defects in primary mouse cells.

    Science.gov (United States)

    Clynes, David; Jelinska, Clare; Xella, Barbara; Ayyub, Helena; Taylor, Stephen; Mitson, Matthew; Bachrati, Csanád Z; Higgs, Douglas R; Gibbons, Richard J

    2014-01-01

    The chromatin remodeling protein ATRX, which targets tandem repetitive DNA, has been shown to be required for expression of the alpha globin genes, for proliferation of a variety of cellular progenitors, for chromosome congression and for the maintenance of telomeres. Mutations in ATRX have recently been identified in tumours which maintain their telomeres by a telomerase independent pathway involving homologous recombination thought to be triggered by DNA damage. It is as yet unknown whether there is a central underlying mechanism associated with ATRX dysfunction which can explain the numerous cellular phenomena observed. There is, however, growing evidence for its role in the replication of various repetitive DNA templates which are thought to have a propensity to form secondary structures. Using a mouse knockout model we demonstrate that ATRX plays a direct role in facilitating DNA replication. Ablation of ATRX alone, although leading to a DNA damage response at telomeres, is not sufficient to trigger the alternative lengthening of telomere pathway in mouse embryonic stem cells.

  13. Live-Cell Imaging of Vaccinia Virus Recombination.

    Directory of Open Access Journals (Sweden)

    Patrick Paszkowski

    2016-08-01

    Full Text Available Recombination between co-infecting poxviruses provides an important mechanism for generating the genetic diversity that underpins evolution. However, poxviruses replicate in membrane-bound cytoplasmic structures known as factories or virosomes. These are enclosed structures that could impede DNA mixing between co-infecting viruses, and mixing would seem to be essential for this process. We hypothesize that virosome fusion events would be a prerequisite for recombination between co-infecting poxviruses, and this requirement could delay or limit viral recombination. We have engineered vaccinia virus (VACV to express overlapping portions of mCherry fluorescent protein fused to a cro DNA-binding element. In cells also expressing an EGFP-cro fusion protein, this permits live tracking of virus DNA and genetic recombination using confocal microscopy. Our studies show that different types of recombination events exhibit different timing patterns, depending upon the relative locations of the recombining elements. Recombination between partly duplicated sequences is detected soon after post-replicative genes are expressed, as long as the reporter gene sequences are located in cis within an infecting genome. The same kinetics are also observed when the recombining elements are divided between VACV and transfected DNA. In contrast, recombination is delayed when the recombining sequences are located on different co-infecting viruses, and mature recombinants aren't detected until well after late gene expression is well established. The delay supports the hypothesis that factories impede inter-viral recombination, but even after factories merge there remain further constraints limiting virus DNA mixing and recombinant gene assembly. This delay could be related to the continued presence of ER-derived membranes within the fused virosomes, membranes that may once have wrapped individual factories.

  14. Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model.

    Directory of Open Access Journals (Sweden)

    Chunqing Ai

    Full Text Available Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model.Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro.Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes.Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

  15. Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model.

    Science.gov (United States)

    Ai, Chunqing; Zhang, Qiuxiang; Ren, Chengcheng; Wang, Gang; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Chen, Yong Q; Chen, Wei

    2014-01-01

    Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model. Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro. Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes. Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

  16. Recombinational DNA repair and human disease

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larry H.; Schild, David

    2002-11-30

    We review the genes and proteins related to the homologous recombinational repair (HRR) pathway that are implicated in cancer through either genetic disorders that predispose to cancer through chromosome instability or the occurrence of somatic mutations that contribute to carcinogenesis. Ataxia telangiectasia (AT), Nijmegen breakage syndrome (NBS), and an ataxia-like disorder (ATLD), are chromosome instability disorders that are defective in the ataxia telangiectasia mutated (ATM), NBS, and Mre11 genes, respectively. These genes are critical in maintaining cellular resistance to ionizing radiation (IR), which kills largely by the production of double-strand breaks (DSBs). Bloom syndrome involves a defect in the BLM helicase, which seems to play a role in restarting DNA replication forks that are blocked at lesions, thereby promoting chromosome stability. The Werner syndrome gene (WRN) helicase, another member of the RecQ family like BLM, has very recently been found to help mediate homologous recombination. Fanconi anemia (FA) is a genetically complex chromosomal instability disorder involving seven or more genes, one of which is BRCA2. FA may be at least partially caused by the aberrant production of reactive oxidative species. The breast cancer-associated BRCA1 and BRCA2 proteins are strongly implicated in HRR; BRCA2 associates with Rad51 and appears to regulate its activity. We discuss in detail the phenotypes of the various mutant cell lines and the signaling pathways mediated by the ATM kinase. ATM's phosphorylation targets can be grouped into oxidative stress-mediated transcriptional changes, cell cycle checkpoints, and recombinational repair. We present the DNA damage response pathways by using the DSB as the prototype lesion, whose incorrect repair can initiate and augment karyotypic abnormalities.

  17. Xylose utilizing recombinant Saccharomyces cerevisiae strains

    Energy Technology Data Exchange (ETDEWEB)

    Walfridsson, M.

    1996-04-01

    Through metabolic engineering, S. cerevisiae was provided with the necessary enzymes required for xylose utilisation during ethanolic fermentation of xylose-rich lignocellulose raw materials. For xylitol production, S. cerevisiae was provided with the Pichia stipitis XYL1 gene encoding xylose reductase (XR). The in-vivo reduction and the following excretion of xylitol, requires a co-substrate for maintenance and cofactor regeneration. Xylitol yields close to 100% were obtained with the XYL1 containing S. cerevisiae. Introducing P. stipitis XYL1 and XYL2 genes, encoding XR and xylitol dehydrogenase (XDH), respectively, enabled S. cerevisiae to convert xylose to xylulose, via xylitol. During the screening work of P. stipitis XDH gene, another gene encoding a polyol dehydrogenase was isolated and cloned in S. cerevisiae. The gene was identified as a D-arabinitol dehydrogenase gene. In P. stipitis it may function as a redox sink by reducing D-ribulose to D-arabinitol. The metabolism through the pentose phosphate pathway (PPP) was enhanced by over-expressing the native genes TKL1 and TAL1 encoding transketolase and transaldolase, respectively, resulting in improved xylose utilisation. The XR and XDH activities in recombinant S. cerevisiae were produced at different levels by constructing yeast vectors in which the PGK1 and ADHI promoters controlled XYL1 and XYL2. With higher XDH than XR activities, less by-products, in the form of xylitol and glycerol, were formed by the recombinant S. cerevisiae strains. The Thermus thermophilus xylA gene encoding a thermostable xylose isomerase was cloned and expressed in S. cerevisiae. The recombinant xylose isomerase was actively produced and a new functional metabolic pathway was established in S. cerevisiae resulting in ethanol production from xylose. 150 refs, 3 figs, 4 tabs

  18. [Establishment of a mutant Lumican transgenic mouse model].

    Science.gov (United States)

    Song, Yanzheng; Zhao, Yanyan; Zhang, Fengju; Yu, Yanqiu; Ma, Ling

    2014-01-01

    Pathological myopia (PM) is a hereditary ocular disease leading to severe loss of visual acuity and blindness. Lumican gene (LUM) is one of those candidate genes of PM. The purpose of this study was to establish a mutant Lumican transgenic mouse model, and to prepare for the further study of the pathogenesis of PM. Experimental study. Mutation of LUM gene was created by site-directed mutagenesis. Recombinant DNA techniques were used for the construction of the pRP. EX3d-EF1A>LUM/flag>IRES/hrGFP transgene. The gene fragments were microinjected into the zygote male pronuclei of BDF1 mice, and then the zygote cells alive were transplanted into the oviduct of acceptor pregnant female ICR mice. The F0 generation transgenic mice obtained were named C57-TgN (LUM)CCMU. Genome DNA from mice tail was detected by PCR and Western blotting. Six of 31 F0 generation mice were positive transgenic mice. The western blotting study showed that the flag-tag was expressed in the mouse tail tissue. Sixty-eight of 128 mice (F1 to F3 generation) were positive transgenic mice, the positive rate is 53.13%. The mutant Lumican (cDNA 596T>C) transgenic mouse model has been established. This model will provide fundamental conditions for studies of the pathogenesis of PM. Also it will be the basis of further studies about the effect of Lumican mutation on the development of PM and structure and function of the extra cellular matrix.

  19. Biochemical and Structural Properties of Mouse Kynurenine Aminotransferase III

    Energy Technology Data Exchange (ETDEWEB)

    Han, Q.; Robinson, H; Cai, T; Tagle, D; Li, J

    2009-01-01

    Kynurenine aminotransferase III (KAT III) has been considered to be involved in the production of mammalian brain kynurenic acid (KYNA), which plays an important role in protecting neurons from overstimulation by excitatory neurotransmitters. The enzyme was identified based on its high sequence identity with mammalian KAT I, but its activity toward kynurenine and its structural characteristics have not been established. In this study, the biochemical and structural properties of mouse KAT III (mKAT III) were determined. Specifically, mKAT III cDNA was amplified from a mouse brain cDNA library, and its recombinant protein was expressed in an insect cell protein expression system. We established that mKAT III is able to efficiently catalyze the transamination of kynurenine to KYNA and has optimum activity at relatively basic conditions of around pH 9.0 and at relatively high temperatures of 50 to 60C. In addition, mKAT III is active toward a number of other amino acids. Its activity toward kynurenine is significantly decreased in the presence of methionine, histidine, glutamine, leucine, cysteine, and 3-hydroxykynurenine. Through macromolecular crystallography, we determined the mKAT III crystal structure and its structures in complex with kynurenine and glutamine. Structural analysis revealed the overall architecture of mKAT III and its cofactor binding site and active center residues. This is the first report concerning the biochemical characteristics and crystal structures of KAT III enzymes and provides a basis toward understanding the overall physiological role of mammalian KAT III in vivo and insight into regulating the levels of endogenous KYNA through modulation of the enzyme in the mouse brain.

  20. Guiding recombinant antivenom development by omics technologies

    DEFF Research Database (Denmark)

    Laustsen, Andreas Hougaard

    2017-01-01

    , endogenous animal proteins with toxin-neutralizing capabilities, and recombinant monoclonal antibodies. Harnessing either of these approaches, antivenom development may benefit from an in-depth understanding of venom compositions and the medical importance of individual venom toxins. Focus is thus also...... directed towards the different omics technologies (particularly venomics, antivenomics, and toxicovenomics) that are being used to uncover novel animal toxins, shed light on venom complexity, and provide directions for how to determine the medical relevance of individual toxins within whole venoms. Finally...

  1. Classification of Recombinant Biologics in the EU

    DEFF Research Database (Denmark)

    Klein, Kevin; De Bruin, Marie L; Broekmans, Andre W

    2015-01-01

    BACKGROUND AND OBJECTIVE: Biological medicinal products (biologics) are subject to specific pharmacovigilance requirements to ensure that biologics are identifiable by brand name and batch number in adverse drug reaction (ADR) reports. Since Member States collect ADR data at the national level...... % of the recombinant biologics from the sample list as biologics, whereas the classification rates in the remaining four Member States ranged between 70 and 88 % for products available on the national market. The interrater reliability for 87 products available on the market in all five Member States was considered...... a publicly available and frequently updated list of centrally authorized biologics....

  2. An introduction to recombination and linkage analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mcpeek, M.S. [Univ. of Chicago, IL (United States)

    1996-12-31

    With a garden as his laboratory, Mendel was able to discern basic probabilistic laws of heredity. Although it first appeared as a baffling exception to one of Mendel`s principles, the phenomenon of variable linkage between characters was soon recognized to be a powerful tool in the process of chromosome mapping and location of genes of interest. In this introduction, we first describe Mendel`s work and the subsequent discovery of linkage. Next we describe the apparent cause of variable linkage, namely recombination, and we introduce linkage analysis. 33 refs., 1 fig., 2 tabs.

  3. Hydrogen recombiner catalyst test supporting data

    Energy Technology Data Exchange (ETDEWEB)

    Britton, M.D.

    1995-01-19

    This is a data package supporting the Hydrogen Recombiner Catalyst Performance and Carbon Monoxide Sorption Capacity Test Report, WHC-SD-WM-TRP-211, Rev 0. This report contains 10 appendices which consist of the following: Mass spectrometer analysis reports: HRC samples 93-001 through 93-157; Gas spectrometry analysis reports: HRC samples 93-141 through 93-658; Mass spectrometer procedure PNL-MA-299 ALO-284; Alternate analytical method for ammonia and water vapor; Sample log sheets; Job Safety analysis; Certificate of mixture analysis for feed gases; Flow controller calibration check; Westinghouse Standards Laboratory report on Bois flow calibrator; and Sorption capacity test data, tables, and graphs.

  4. Mouse Models of Diabetic Neuropathy

    Science.gov (United States)

    O'Brien, Phillipe D.; Sakowski, Stacey A.; Feldman, Eva L.

    2014-01-01

    Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes and is associated with significant morbidity and mortality. DPN is characterized by progressive, distal-to-proximal degeneration of peripheral nerves that leads to pain, weakness, and eventual loss of sensation. The mechanisms underlying DPN pathogenesis are uncertain, and other than tight glycemic control in type 1 patients, there is no effective treatment. Mouse models of type 1 (T1DM) and type 2 diabetes (T2DM) are critical to improving our understanding of DPN pathophysiology and developing novel treatment strategies. In this review, we discuss the most widely used T1DM and T2DM mouse models for DPN research, with emphasis on the main neurologic phenotype of each model. We also discuss important considerations for selecting appropriate models for T1DM and T2DM DPN studies and describe the promise of novel emerging diabetic mouse models for DPN research. The development, characterization, and comprehensive neurologic phenotyping of clinically relevant mouse models for T1DM and T2DM will provide valuable resources for future studies examining DPN pathogenesis and novel therapeutic strategies. PMID:24615439

  5. Mouse Models of Rheumatoid Arthritis.

    Science.gov (United States)

    Caplazi, P; Baca, M; Barck, K; Carano, R A D; DeVoss, J; Lee, W P; Bolon, B; Diehl, L

    2015-09-01

    Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disorder characterized by synovitis that leads to cartilage and bone erosion by invading fibrovascular tissue. Mouse models of RA recapitulate many features of the human disease. Despite the availability of medicines that are highly effective in many patient populations, autoimmune diseases (including RA) remain an area of active biomedical research, and consequently mouse models of RA are still extensively used for mechanistic studies and validation of therapeutic targets. This review aims to integrate morphologic features with model biology and cover the key characteristics of the most commonly used induced and spontaneous mouse models of RA. Induced models emphasized in this review include collagen-induced arthritis and antibody-induced arthritis. Collagen-induced arthritis is an example of an active immunization strategy, whereas antibody- induced arthritis models, such as collagen antibody-induced arthritis and K/BxN antibody transfer arthritis, represent examples of passive immunization strategies. The coverage of spontaneous models in this review is focused on the TNFΔ (ARE) mouse, in which arthritis results from overexpression of TNF-α, a master proinflammatory cytokine that drives disease in many patients. © The Author(s) 2015.

  6. High-throughput mouse phenotyping.

    Science.gov (United States)

    Gates, Hilary; Mallon, Ann-Marie; Brown, Steve D M

    2011-04-01

    Comprehensive phenotyping will be required to reveal the pleiotropic functions of a gene and to uncover the wider role of genetic loci within diverse biological systems. The challenge will be to devise phenotyping approaches to characterise the thousands of mutants that are being generated as part of international efforts to acquire a mutant for every gene in the mouse genome. In order to acquire robust datasets of broad based phenotypes from mouse mutants it is necessary to design and implement pipelines that incorporate standardised phenotyping platforms that are validated across diverse mouse genetics centres or mouse clinics. We describe here the rationale and methodology behind one phenotyping pipeline, EMPReSSslim, that was designed as part of the work of the EUMORPHIA and EUMODIC consortia, and which exemplifies some of the challenges facing large-scale phenotyping. EMPReSSslim captures a broad range of data on diverse biological systems, from biochemical to physiological amongst others. Data capture and dissemination is pivotal to the operation of large-scale phenotyping pipelines, including the definition of parameters integral to each phenotyping test and the associated ontological descriptions. EMPReSSslim data is displayed within the EuroPhenome database, where a variety of tools are available to allow the user to search for interesting biological or clinical phenotypes. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Viral Delivery of GFP-Dependent Recombinases to the Mouse Brain.

    Science.gov (United States)

    Tang, Jonathan C Y; Rudolph, Stephanie; Cepko, Constance L

    2017-01-01

    Many genetic tools have been developed that use green fluorescent protein (GFP) and its derivatives for labeling specific cell populations in organisms and in cell culture. To extend the use of GFP beyond labeling purposes, we developed methods and reagents that use GFP as a driver of biological activities. We used nanobodies that bind GFP to engineer CRE-DOG and Flp-DOG, recombinases that can induce Cre/lox and Flp/FRT recombination in a GFP-dependent manner, respectively. Here, we present a protocol to deliver CRE-DOG and Flp-DOG into the mouse brain by recombinant AAV infection. This protocol enables one to manipulate gene expression specifically in GFP-expressing cells, found either in transgenic GFP reporter lines or in cells made to express GFP by other transduction methods.

  8. The Use of Recombinant 31 kDa Antigens of Trichinella spiralis for Serodiagnosis of Experimental Trichinellosis

    Science.gov (United States)

    WANG, Li; TIAN, Xiang Yu; SUN, Ge Ge; LIU, Ruo Dan; LIU, Li Na; ZHANG, Xi; JIANG, Peng; WANG, Zhong Quan; CUI, Jing

    2015-01-01

    Background: We have previously reported that a 31 kDa protein was screened from the excretory-secretory (ES) proteins of Tichinella spiralis muscle larvae (ML) by immunoproteomics using early infection sera, and the gene encoding a 31 kDa protein from T. spiralis was cloned and expressed in an E. coli expression system. In this study, the recombinant 31 kDa antigens were used for detection of anti-Trichinella antibodies in serum of experimentally infected mice by ELISA. Methods: Anti-Trichinella IgG antibodies in sera of mice infected with Trichinella were assayed by ELISA with recombinant 31 kDa antigens, and its sensitivity and specificity were compared with ELISA with ES antigen. Results: The sensitivity and specificity of ELISA with recombinant antigens was 96.67% (29/30) and 96.87% (62/64), compared with 100% (30/30) and 98.44% (63/64) of ELISA with ES antigens was (P>0.05). In heavily, moderately and lightly infected mice (500, 300 and 100 larvae/mouse), anti-Trichinella antibodies were firstly detected by ELISA with recombinant antigens at 8, 12 and 14 dpi, respectively; then increased rapidly with a detection rate of 100% respectively at 28, 22 and 30 dpi. While the antibodies were firstly detected by ELISA with ES antigens at 10, 8 and 10 dpi, respectively, the antibody positive rate reached 100% at 14, 12 and 22 dpi, respectively. Conclusion: The recombinant 31 kDa antigens of T. spirali had a good sensitivity and specificity for detecting anti-Trichinella antibodies and might be the potential diagnostic antigen for trichinellosis. PMID:26246820

  9. Induction of antigen-specific immune responses in mice by recombinant baculovirus expressing premembrane and envelope proteins of West Nile virus

    Directory of Open Access Journals (Sweden)

    Zhu Bibo

    2012-07-01

    Full Text Available Abstract Background West Nile Virus (WNV is an emerging arthropod-born flavivirus with increasing distribution worldwide that is responsible for a large proportion of viral encephalitis in humans and horses. Given that there are no effective antiviral drugs available for treatment of the disease, efforts have been directed to develop vaccines to prevent WNV infection. Recently baculovirus has emerged as a novel and attractive gene delivery vehicle for mammalian cells. Results In the present study, recombinant baculoviruses expressing WNV premembrane (prM and envelope (E proteins under the cytomegalovirus (CMV promoter with or without vesicular stomatitis virus glycoprotein (VSV/G were constructed. The recombinant baculoviruses designated Bac-G-prM/E and Bac-prM/E, efficiently express E protein in mammalian cells. Intramuscular injection of the two recombinant baculoviruses (at doses of 108 or 109 PFU/mouse induced the production of WNV-specific antibodies, neutralizing antibodies as well as gamma interferon (IFN-γ in a dose-dependent pattern. Interestingly, the recombinant baculovirus Bac-G-prM/E was found to be a more efficient immunogen than Bac-prM/E to elicit a robust immune response upon intramuscular injection. In addition, inoculation of baculovirus resulted in the secretion of inflammatory cytokines, such as TNF-α, IL-2 and IL-6. Conclusions These recombinant baculoviruses are capable of eliciting robust humoral and cellular immune responses in mice, and may be considered as novel vaccine candidates for West Nile Virus.

  10. Immunization with recombinant beta-tubulin from Trypanosoma evansi induced protection against T. evansi, T. equiperdum and T. b. brucei infection in mice.

    Science.gov (United States)

    Li, S-Q; Fung, M-C; Reid, S A; Inoue, N; Lun, Z-R

    2007-04-01

    The beta-tubulin gene of Trypanosoma evansi (STIB 806) was cloned and expressed in Escherichia coli. The predicted amino acid sequence of T. evansi beta-tubulin shows 100%, 99.8%, 99.1%, and 98.6% homology with T. equiperdum, T. b. brucei, T. cruzi and T. danilewskyi, respectively, but is diverse from that of T. cyclops, showing only 51.6% of homology. Recombinant beta-tubulin was expressed as inclusion bodies in E. coli. It was purified and renatured for immunological studies. Mice immunized with the renatured recombinant beta-tubulin were protected from lethal challenge with T. evansi STIB 806, T. equiperdum STIB 818 and T. b. brucei STIB 940, showing 83.3%, 70% and 76.7% protection, respectively. Serum collected from the rabbit immunized with recombinant beta-tubulin inhibited the growth of T. evansi, T. equiperdum and T. b. brucei in vitro. Serum from mice and rabbits immunized with recombinant beta-tubulin recognized only T. evansi beta-tubulin and not mouse beta-tubulin. The results of this study demonstrated that the recombinant T. evansi beta-tubulin is a potential candidate for the development of a vaccine to prevent animal trypanosomiasis caused by these three trypanosome species.

  11. Humanized c-Myc mouse.

    Directory of Open Access Journals (Sweden)

    Frank M Lehmann

    Full Text Available BACKGROUND: A given tumor is usually dependent on the oncogene that is activated in the respective tumor entity. This phenomenon called oncogene addiction provides the rationale for attempts to target oncogene products in a therapeutic manner, be it by small molecules, by small interfering RNAs (siRNA or by antigen-specific T cells. As the proto-oncogene product is required also for the function of normal cells, this raises the question whether there is a therapeutic window between the adverse effects of specific inhibitors or T cells to normal tissue that may limit their application, and their beneficial tumor-specific therapeutic action. To address this crucial question, suitable mouse strains need to be developed, that enable expression of the human proto-oncogene not only in tumor but also in normal cells. The aim of this work is to provide such a mouse strain for the human proto-oncogene product c-MYC. PRINCIPAL FINDINGS: We generated C57BL/6-derived embryonic stem cells that are transgenic for a humanized c-Myc gene and established a mouse strain (hc-Myc that expresses human c-MYC instead of the murine ortholog. These transgenic animals harbor the humanized c-Myc gene integrated into the endogenous murine c-Myc locus. Despite the lack of the endogenous murine c-Myc gene, homozygous mice show a normal phenotype indicating that human c-MYC can replace its murine ortholog. CONCLUSIONS: The newly established hc-Myc mouse strain provides a model system to study in detail the adverse effects of therapies that target the human c-MYC protein. To mimic the clinical situation, hc-Myc mice may be cross-bred to mice that develop tumors due to overexpression of human c-MYC. With these double transgenic mice it will be possible to study simultaneously the therapeutic efficiency and adverse side effects of MYC-specific therapies in the same mouse.

  12. Homologous recombination-mediated cloning and manipulation of genomic DNA regions using Gateway and recombineering systems.

    Science.gov (United States)

    Rozwadowski, Kevin; Yang, Wen; Kagale, Sateesh

    2008-11-17

    Employing genomic DNA clones to characterise gene attributes has several advantages over the use of cDNA clones, including the presence of native transcription and translation regulatory sequences as well as a representation of the complete repertoire of potential splice variants encoded by the gene. However, working with genomic DNA clones has traditionally been tedious due to their large size relative to cDNA clones and the presence, absence or position of particular restriction enzyme sites that may complicate conventional in vitro cloning procedures. To enable efficient cloning and manipulation of genomic DNA fragments for the purposes of gene expression and reporter-gene studies we have combined aspects of the Gateway system and a bacteriophage-based homologous recombination (i.e. recombineering) system. To apply the method for characterising plant genes we developed novel Gateway and plant transformation vectors that are of small size and incorporate selectable markers which enable efficient identification of recombinant clones. We demonstrate that the genomic coding region of a gene can be directly cloned into a Gateway Entry vector by recombineering enabling its subsequent transfer to Gateway Expression vectors. We also demonstrate how the coding and regulatory regions of a gene can be directly cloned into a plant transformation vector by recombineering. This construct was then rapidly converted into a novel Gateway Expression vector incorporating cognate 5' and 3' regulatory regions by using recombineering to replace the intervening coding region with the Gateway Destination cassette. Such expression vectors can be applied to characterise gene regulatory regions through development of reporter-gene fusions, using the Gateway Entry clones of GUS and GFP described here, or for ectopic expression of a coding region cloned into a Gateway Entry vector. We exemplify the utility of this approach with the Arabidopsis PAP85 gene and demonstrate that the expression

  13. Antagonism of recombinant and native GluK3-containing kainate receptors.

    Science.gov (United States)

    Perrais, David; Pinheiro, Paulo S; Jane, David E; Mulle, Christophe

    2009-01-01

    A number of kainate receptor antagonists have shown selectivity for receptors containing the GluK1 subunit. Here, we analyze the effects of these GluK1 antagonists on currents mediated by recombinant homomeric GluK3 and heteromeric GluK2/3 receptors expressed in HEK 293 cells and activated by fast application of glutamate. We show that, amongst these compounds, UBP302, UBP310 and UBP316 effectively block recombinant homomeric GluK3 receptors. However, these antagonists are ineffective in blocking homomeric GluK2 or heteromeric GluK2/3 receptors. In addition, these antagonists do not affect presynaptic kainate receptors at mouse hippocampal mossy fibre synapses, which are thought to be composed of GluK2 and GluK3 subunits. Moreover, the AMPA receptor-selective non-competitive antagonist GYKI 53655 blocks, at high concentrations, GluK3-containing receptors and decreases short-term plasticity at mossy fibre synapses. These results expand the range of targets of kainate receptor antagonists and provide pharmacological tools to study the elusive mechanisms of neurotransmitter control by presynaptic kainate receptors.

  14. A recombinant cystatin from Ascaris lumbricoides attenuates inflammation of DSS-induced colitis.

    Science.gov (United States)

    Coronado, S; Barrios, L; Zakzuk, J; Regino, R; Ahumada, V; Franco, L; Ocampo, Y; Caraballo, L

    2017-04-01

    Helminthiasis may ameliorate inflammatory diseases, such as inflammatory bowel disease and asthma. Information about immunomodulators from Ascaris lumbricoides is scarce, but could be important considering the co-evolutionary relationships between helminths and humans. We evaluated the immunomodulatory effects of a recombinant cystatin from A. lumbricoides on an acute model of dextran sodium sulphate (DSS)-induced colitis in mice. From an A. lumbricoides cDNA library, we obtained a recombinant cystatin (rAl-CPI). Protease activity inhibition was demonstrated on cathepsin B and papain. Immunomodulatory effects were evaluated at two intraperitoneal doses (0.5 and 0.25 μg/G) on mice with DSS-induced colitis. Body weight, colon length, Disease Activity Index (DAI), histological inflammation score, myeloperoxidase (MPO) activity, gene expression of cytokines and cytokines levels in colon tissue were analysed. Treatment with rAl-CPI significantly reduced DAI, MPO activity and inflammation score without toxic effects. Also, IL-10 and TGF-B gene overexpression was observed in rAl-CPI-treated group compared to DSS-exposed control and healthy mice. Furthermore, a reduction in IL-6 and TNF-A expression was found, and this was confirmed by the levels of these cytokines in colonic tissue. In conclusion, rAl-CPI reduces inflammation in a mouse model of DSS-induced colitis, probably by increasing the expression of anti-inflammatory cytokines and reducing pro-inflammatory ones. © 2017 John Wiley & Sons Ltd.

  15. Peptide-based synthetic recombinant vaccines with anti-viral efficacy.

    Science.gov (United States)

    Arnon, R; Tarrab-Hazdai, R; Ben-Yedidia, T

    2001-01-01

    Synthetic recombinant vaccines are constructs in which a synthetic oligonucleotide coding for a protective epitope is inserted into an adequate gene for expression of the epitope. We report the results obtained using recombinant flagella of Salmonella vaccine strain expressing epitopes of influenza virus or of the parasite Schistosoma mansoni. In the case of influenza virus, three conserved epitopes of the haemagglutinin and the nucleoprotein of the virus inducing B- and T-cell immune response, were expressed and the flagella were used for intranasal immunization without any adjuvant. Both humoral and cellular immune responses specific to the virus induced in mice cross-strain long-term protection against challenge infection. Aged mice were also able to resist infection. For the design of a human influenza vaccine, epitopes recognized by the HLAs prevalent in Caucasian populations were used, and the resulting vaccine was evaluated in human/mouse radiation chimaera in which human PBMC are functionally engrafted. The vaccinated mice demonstrated efficient clearance of the virus after challenge and resistance to lethal infection. In the case of the parasitic disease schistosomiasis, a 14-residue peptide denoted 9B peptide 1 was expressed in the flagella. Intranasal vaccination of mice with this construct, without the use of adjuvant, resulted in 40% protection against challenge infection. Copyright 2001 The International Association for Biologicals.

  16. Recombination and synaptic adjustment in oocytes of mice heterozygous for a large paracentric inversion.

    Science.gov (United States)

    Torgasheva, Anna A; Rubtsov, Nikolai B; Borodin, Pavel M

    2013-03-01

    Homologous chromosome synapsis in inversion heterozygotes results in the formation of inversion loops. These loops might be transformed into straight, non-homologously paired bivalents via synaptic adjustment. Synaptic adjustment was discovered 30 years ago; however, its relationship with recombination has remained unclear. We analysed this relationship in female mouse embryos heterozygous for large paracentric inversion In(1)1Rk using immunolocalisation of the synaptonemal complex (SYCP3) and mature recombination nodules (MLH1) proteins. The frequency of cells containing bivalents with inversion loops decreased from 69 % to 28 % during pachytene. If an MLH1 focus was present in the non-homologously paired inverted region of the straight bivalent, it was always located in the middle of the inversion. Most of the small, incompletely adjusted loops contained MLH1 foci near the points at which pairing partners were switched. This observation indicates that the degree of synaptic adjustment depended on the crossover position. Complete synaptic adjustment was only possible if a crossover (CO) was located exactly in the middle of the inversion. If a CO was located at any other site, this interrupted synaptic adjustment and resulted in inversion loops of different sizes with an MLH1 focus at or near the edge of the remaining loop.

  17. The estimation of recombination rates from population genetic data

    OpenAIRE

    2007-01-01

    Genetic recombination is an important process that generates new combinations of genes on which natural selection can operate. As such, an understanding of recombination in the human genome will provide insight into the evolutionary processes that have shaped our genetic history. The aim of this thesis is to use samples of population genetic data to explore the patterns of variation in the rate of recombination in the human genome. To do this I introduce a novel means of estimating recombinat...

  18. Distant Recombination and the Creation of Basic Inventions

    DEFF Research Database (Denmark)

    Barirani, Ahmad; Beaudry, Catherine; Agard, Bruno

    2015-01-01

    This article explores whether the relationship between the breath of technological integration (recombination distance) and the breath of an invention׳s subsequent application (basicness) is moderated by the sector of activity (private or public), science-linkage strength and industry......; increasing reliance upon basic science moderates the relationship between recombination distance and basicness; and increases to recombination distance in emerging science-based industries increases invention basicness at a higher rate. These findings have implications regarding the debate around...

  19. Surface recombination velocity of silicon wafers by photoluminescence

    Science.gov (United States)

    Baek, D.; Rouvimov, S.; Kim, B.; Jo, T.-C.; Schroder, D. K.

    2005-03-01

    Photoluminescence (PL) and optical reflection measurements, obtained in the two-wavelength SiPHER PL instrument, are used to determine the surface recombination velocity of silicon wafers. Local measurements and contour maps are possible allowing surface recombination maps to be displayed. This instrument also allows doping and trap density measurements. Surface recombination velocities from 10 to 106cm/s can be measured on low or high resistivity polished and epitaxial wafers.

  20. Generating a Prion with Bacterially Expressed Recombinant Prion Protein**

    OpenAIRE

    Wang, Fei; Wang, Xinhe; Yuan, Chong-Gang; Ma, Jiyan

    2010-01-01

    The prion hypothesis posits that a misfolded form of prion protein (PrP) is responsible for the infectivity of prion disease. Using recombinant murine PrP purified from Escherichia coli, we created a recombinant prion with the hallmarks of the pathogenic PrP isoform: aggregated, protease-resistant, and self-perpetuating. After intracerebral injection of the recombinant prion, wild-type mice developed neurological signs in ~130 days and reached the terminal stage of disease in ~150 days. Chara...

  1. Single-crossover recombination in discrete time.

    Science.gov (United States)

    von Wangenheim, Ute; Baake, Ellen; Baake, Michael

    2010-05-01

    Modelling the process of recombination leads to a large coupled nonlinear dynamical system. Here, we consider a particular case of recombination in discrete time, allowing only for single crossovers. While the analogous dynamics in continuous time admits a closed solution (Baake and Baake in Can J Math 55:3-41, 2003), this no longer works for discrete time. A more general model (i.e. without the restriction to single crossovers) has been studied before (Bennett in Ann Hum Genet 18:311-317, 1954; Dawson in Theor Popul Biol 58:1-20, 2000; Linear Algebra Appl 348:115-137, 2002) and was solved algorithmically by means of Haldane linearisation. Using the special formalism introduced by Baake and Baake (Can J Math 55:3-41, 2003), we obtain further insight into the single-crossover dynamics and the particular difficulties that arise in discrete time. We then transform the equations to a solvable system in a two-step procedure: linearisation followed by diagonalisation. Still, the coefficients of the second step must be determined in a recursive manner, but once this is done for a given system, they allow for an explicit solution valid for all times.

  2. Modified Fragmentation Function from Quark Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, A.; Wang, Enke; Wang, Xin-Nian

    2005-07-26

    Within the framework of the constituent quark model, it isshown that the single hadron fragmentation function of a parton can beexpressed as a convolution of shower diquark or triquark distributionfunction and quark recombination probability, if the interference betweenamplitudes of quark recombination with different momenta is neglected.Therecombination probability is determined by the hadron's wavefunction inthe constituent quark model. The shower diquark or triquark distributionfunctions of a fragmenting jet are defined in terms of overlappingmatrices of constituent quarks and parton field operators. They aresimilar in form to dihadron or trihadron fragmentation functions in termsof parton operator and hadron states. Extending the formalism to thefield theory at finite temperature, we automatically derive contributionsto the effective single hadron fragmentation function from therecombination of shower and thermal constituent quarks. Suchcontributions involve single or diquark distribution functions which inturn can be related to diquark or triquark distribution functions via sumrules. We also derive QCD evolution equations for quark distributionfunctions that in turn determine the evolution of the effective jetfragmentation functions in a thermal medium.

  3. The landscape of recombination in African Americans

    Science.gov (United States)

    Hinch, Anjali G.; Tandon, Arti; Patterson, Nick; Song, Yunli; Rohland, Nadin; Palmer, Cameron D.; Chen, Gary K.; Wang, Kai; Buxbaum, Sarah G.; Akylbekova, Meggie; Aldrich, Melinda C.; Ambrosone, Christine B.; Amos, Christopher; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Bock, Cathryn H.; Boerwinkle, Eric; Cai, Qiuyin; Caporaso, Neil; Casey, Graham; Cupples, L. Adrienne; Deming, Sandra L.; Diver, W. Ryan; Divers, Jasmin; Fornage, Myriam; Gillanders, Elizabeth M.; Glessner, Joseph; Harris, Curtis C.; Hu, Jennifer J.; Ingles, Sue A.; Isaacs, Williams; John, Esther M.; Kao, W. H. Linda; Keating, Brendan; Kittles, Rick A.; Kolonel, Laurence N.; Larkin, Emma; Le Marchand, Loic; McNeill, Lorna H.; Millikan, Robert C.; Murphy, Adam; Musani, Solomon; Neslund-Dudas, Christine; Nyante, Sarah; Papanicolaou, George J.; Press, Michael F.; Psaty, Bruce M.; Reiner, Alex P.; Rich, Stephen S.; Rodriguez-Gil, Jorge L.; Rotter, Jerome I.; Rybicki, Benjamin A.; Schwartz, Ann G.; Signorello, Lisa B.; Spitz, Margaret; Strom, Sara S.; Thun, Michael J.; Tucker, Margaret A.; Wang, Zhaoming; Wiencke, John K.; Witte, John S.; Wrensch, Margaret; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A.; Zheng, Wei; Ziegler, Regina G.; Zhu, Xiaofeng; Redline, Susan; Hirschhorn, Joel N.; Henderson, Brian E.; Taylor, Herman A.; Price, Alkes L.; Hakonarson, Hakon; Chanock, Stephen J.; Haiman, Christopher A.; Wilson, James G.; Reich, David; Myers, Simon R.

    2011-01-01

    Recombination, together with mutation, is the ultimate source of genetic variation in populations. We leverage the recent mixture of people of African and European ancestry in the Americas to build a genetic map measuring the probability of crossing-over at each position in the genome, based on about 2.1 million crossovers in 30,000 unrelated African Americans. At intervals of more than three megabases it is nearly identical to a map built in Europeans. At finer scales it differs significantly, and we identify about 2,500 recombination hotspots that are active in people of West African ancestry but nearly inactive in Europeans. The probability of a crossover at these hotspots is almost fully controlled by the alleles an individual carries at PRDM9 (P<10−245). We identify a 17 base pair DNA sequence motif that is enriched in these hotspots, and is an excellent match to the predicted binding target of African-enriched alleles of PRDM9. PMID:21775986

  4. Recombinant antigens for immunodiagnosis of cystic echinococcosis

    Directory of Open Access Journals (Sweden)

    Li Jun

    2004-01-01

    Full Text Available Three cDNAs, termed EpC1, TPxEg and EgG5, were isolated by immunoscreening from an Echinococcus granulosus cDNA library. The recombinant phages exhibited strong reactivity with sera from humans with confirmed cystic echinococcosis (CE and with sera from mice infected with E. granulosus oncospheres. The cDNAs were subcloned into a pET vector, expressed as fusion proteins tagged with GST and affinity purified against the GST tag. Of the three recombinant proteins, EpC1 achieved the highest performance for serodiagnosis of CE in Western blot analysis using a panel of clinically defined human sera to initially address the sensitivity and specificity of the molecules. The protein yielded an overall sensitivity of 92.2% and specificity of 95.6%, levels unprecedented taking into account the large panel of 896 human sera that were tested. The strategy used may also prove suitable for improved immunodiagnosis of other parasitic infections.

  5. Recombinant protein scaffolds for tissue engineering.

    Science.gov (United States)

    Werkmeister, Jerome A; Ramshaw, John A M

    2012-02-01

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation.

  6. Recombinant viral vaccines for enzootic bovine leucosis.

    Science.gov (United States)

    Daniel, R C; Gatei, M H; Good, M F; Boyle, D B; Lavin, M F

    1993-10-01

    Recently published studies on the development and use of recombinant vaccinia virus (VV) vaccines incorporating either the complete envelope (env) gene or only a fragment of the env gene consisting of the coding sequence for the env glycoprotein 51 (gp51) and part of gp30 of the bovine leukaemia virus (BLV) are described. It has been reported that vaccination of sheep with recombinant VV vaccines containing the complete env gene appears to protect sheep against challenge infection with BLV. The evidence for this protection is based on the lack of persistence of high titres of anti-gp51 antibodies compared with unvaccinated BLV infected controls, on the enhanced CD4 proliferative responses to specific BLV gp51 synthetic peptides in the vaccinated sheep, and on the inability to detect BLV pro-virus by polymerase chain reaction in the vaccinated sheep after 4 months following challenge infection compared with continual detection in unvaccinated sheep over a 16 month trial period. It has been suggested that cell-mediated immune responses may be an important aspect of protective immunity against BLV infection and it has been reported that large tracts of amino acid sequences within the env and pol genes are highly conserved in different isolates from different countries which is of importance in designing peptide derived vaccines.

  7. Molecular farming of recombinant antibodies in plants.

    Science.gov (United States)

    Schillberg, S; Fischer, R; Emans, N

    2003-03-01

    Antibodies represent a large proportion of therapeutic drugs currently in development. In most cases, they are produced in mammalian cell lines or transgenic animals because these have been shown to fold and assemble the proteins correctly and generate authentic glycosylation patterns. However, such expression systems are expensive, difficult to scale up and there are safety concerns due to potential contamination with pathogenic organisms or oncogenic DNA sequences. Plants represent an inexpensive, efficient and safe alternative for the production of recombinant antibodies. Research over the last 10 years has shown that plants can produce a variety of functional antibodies and there is now intense interest in scaling up production to commercial levels. In this review, we discuss the advantages of plants over traditional expression systems, describe how antibody expression in plants is achieved and optimized and then consider the practical issues concerning large-scale molecular farming in plants. The first plant-produced therapeutic antibodies are already in clinical trials, and, given the economic benefits of this production system, we are likely to see many more recombinant antibodies produced in this manner in the future.

  8. Immunoglobulin class-switch recombination deficiencies.

    Science.gov (United States)

    Durandy, Anne; Kracker, Sven

    2012-07-30

    Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.

  9. Long-term Cre-mediated Retrograde Tagging of Neurons Using a Novel Recombinant Pseudorabies Virus

    Directory of Open Access Journals (Sweden)

    Hassana eOyibo

    2014-09-01

    Full Text Available Brain regions contain diverse populations of neurons that project to different long-range targets. The study of these subpopulations in circuit function and behavior requires a toolkit to characterize and manipulate their activity in vivo. We have developed a novel set of reagents based on Pseudorabies Virus (PRV for efficient and long-term genetic tagging of neurons based on their projection targets. By deleting IE180, the master transcriptional regulator in the PRV genome, we have produced a mutant virus capable of infection and transgene expression in neurons but unable to replicate in or spread from those neurons. IE180-null mutants showed no cytotoxicity, and infected neurons exhibited normal physiological function more than 45 days after infection, indicating the utility of these engineered viruses for chronic experiments. To enable rapid and convenient construction of novel IE180-null recombinants, we engineered a bacterial artificial chromosome (BAC shuttle-vector system for moving new constructs into the PRV IE180-null genome. Using this system we generated an IE180-null recombinant virus expressing the site-specific recombinase Cre. This Cre-expressing virus (PRV-hSyn-Cre efficiently and robustly infects neurons in vivo and activates transgene expression from Cre-dependent vectors in local and retrograde projecting populations of neurons in the mouse. We also generated an assortment of recombinant viruses expressing fluorescent proteins (mCherry, EGFP, ECFP. These viruses exhibit long-term labeling of neurons in vitro but transient labeling in vivo. Together these novel IE180-null PRV reagents expand the toolkit for targeted gene expression in the brain, facilitating functional dissection of neuronal circuits in vivo.

  10. Interplay between synaptonemal complex, homologous recombination, and centromeres during mammalian meiosis.

    Directory of Open Access Journals (Sweden)

    Huanyu Qiao

    2012-06-01

    Full Text Available The intimate synapsis of homologous chromosome pairs (homologs by synaptonemal complexes (SCs is an essential feature of meiosis. In many organisms, synapsis and homologous recombination are interdependent: recombination promotes SC formation and SCs are required for crossing-over. Moreover, several studies indicate that initiation of SC assembly occurs at sites where crossovers will subsequently form. However, recent analyses in budding yeast and fruit fly imply a special role for centromeres in the initiation of SC formation. In addition, in budding yeast, persistent SC-dependent centromere-association facilitates the disjunction of chromosomes that have failed to become connected by crossovers. Here, we examine the interplay between SCs, recombination, and centromeres in a mammal. In mouse spermatocytes, centromeres do not serve as SC initiation sites and are invariably the last regions to synapse. However, centromeres are refractory to de-synapsis during diplonema and remain associated by short SC fragments. Since SC-dependent centromere association is lost before diakinesis, a direct role in homolog segregation seems unlikely. However, post-SC disassembly, we find evidence of inter-centromeric connections that could play a more direct role in promoting homolog biorientation and disjunction. A second class of persistent SC fragments is shown to be crossover-dependent. Super-resolution structured-illumination microscopy (SIM reveals that these structures initially connect separate homolog axes and progressively diminish as chiasmata form. Thus, DNA crossing-over (which occurs during pachynema and axis remodeling appear to be temporally distinct aspects of chiasma formation. SIM analysis of the synapsis and crossover-defective mutant Sycp1⁻/⁻ implies that SCs prevent unregulated fusion of homolog axes. We propose that SC fragments retained during diplonema stabilize nascent bivalents and help orchestrate local chromosome reorganization

  11. Bacterial-based systems for expression and purification of recombinant Lassa virus proteins of immunological relevance

    Directory of Open Access Journals (Sweden)

    Cashman Kathleen A

    2008-06-01

    Full Text Available Abstract Background There is a significant requirement for the development and acquisition of reagents that will facilitate effective diagnosis, treatment, and prevention of Lassa fever. In this regard, recombinant Lassa virus (LASV proteins may serve as valuable tools in diverse antiviral applications. Bacterial-based systems were engineered for expression and purification of recombinant LASV nucleoprotein (NP, glycoprotein 1 (GP1, and glycoprotein 2 (GP2. Results Full-length NP and the ectodomains of GP1 and GP2 were generated as maltose-binding protein (MBP fusions in the Rosetta strains of Escherichia coli (E. coli using pMAL-c2x vectors. Average fusion protein yields per liter of culture for MBP-NP, MBP-GP1, and MBP-GP2 were 10 mg, 9 mg, and 9 mg, respectively. Each protein was captured from cell lysates using amylose resin, cleaved with Factor Xa, and purified using size-exclusion chromatography (SEC. Fermentation cultures resulted in average yields per liter of 1.6 mg, 1.5 mg, and 0.7 mg of purified NP, GP1 and GP2, respectively. LASV-specific antibodies in human convalescent sera specifically detected each of the purified recombinant LASV proteins, highlighting their utility in diagnostic applications. In addition, mouse hyperimmune ascitic fluids (MHAF against a panel of Old and New World arenaviruses demonstrated selective cross reactivity with LASV proteins in Western blot and enzyme-linked immunosorbent assay (ELISA. Conclusion These results demonstrate the potential for developing broadly reactive immunological assays that employ all three arenaviral proteins individually and in combination.

  12. Synthesis of part of a mouse immunoglobulin light chain in a bacterial clone.

    OpenAIRE

    Amster, O; Salomon, D; Zemel, O; Zamir, A; Zeelon, E P; Kantor, F; Schechter, I

    1980-01-01

    We have cloned double stranded cDNA sequences encoding a mouse immunoglobulin light chain (L-321) into the PstI site of the beta-lactamase gene of plasmid pBR322 by the oligo (dG)-oligo (dC) tailing procedure. Escherichia coli X1776 transformed by the recombinant plasmids were screened for the expression of L-321 antigenic determinants by a newly developed in situ radio-immunoassay. One out of seven transformants screened was found to synthesize an L-chain like protein. Each bacterial cell pr...

  13. Charge Recombination Suppressed by Destructive Quantum Interference in Heterojunction Materials.

    Science.gov (United States)

    Tempelaar, Roel; Koster, L Jan Anton; Havenith, Remco W A; Knoester, Jasper; Jansen, Thomas L C

    2016-01-07

    We show that charge recombination in ordered heterojunctions depends sensitively on the degree of coherent delocalization of charges at the donor-acceptor interface. Depending on the relative sign of the electron and hole transfer integrals, such delocalization can dramatically suppress recombination through destructive quantum interference. This could explain why measured recombination rates are significantly lower than predictions based on Langevin theory for a variety of organic bulk heterojunctions. Moreover, it opens up a design strategy for photovoltaic devices with enhanced efficiencies through coherently suppressed charge recombination.

  14. Bias-Variance Tradeoffs in Recombination Rate Estimation.

    Science.gov (United States)

    Stone, Eric A; Singh, Nadia D

    2016-02-01

    In 2013, we and coauthors published a paper characterizing rates of recombination within the 2.1-megabase garnet-scalloped (g-sd) region of the Drosophila melanogaster X chromosome. To extract the signal of recombination in our high-throughput sequence data, we adopted a nonparametric smoothing procedure, reducing variance at the cost of biasing individual recombination rates. In doing so, we sacrificed accuracy to gain precision-precision that allowed us to detect recombination rate heterogeneity. Negotiating the bias-variance tradeoff enabled us to resolve significant variation in the frequency of crossing over across the garnet-scalloped region. Copyright © 2016 by the Genetics Society of America.

  15. Expression and purification of recombinant nattokinase in Spodoptera frugiperda cells.

    Science.gov (United States)

    Li, Xiaoxiang; Wang, Xiaoli; Xiong, Shaoling; Zhang, Jing; Cai, Litao; Yang, Yanyan

    2007-10-01

    A recombinant baculovirus, rv-egfp-NK, containing a reporter gene encoding the enhanced green fluorescent protein (EGFP), was used to express nattokinase (NK), a fibrinolytic enzyme, in Spodoptera frugiperda (SF-9) cells. The recombinant protein also included a histidine tag for purification using Ni(2+) resins. The recombinant NK, approximately 30 kDa, retained fibrinolytic activity (60 U/ml). The integration of the EGFP expression cassette in the Bac-to-Bac system is thus an effective method for the expression and purification of recombinant NK protein in Spodoptera frugiperda insect cells.

  16. Recombinant pharmaceuticals from microbial cells: a 2015 update

    National Research Council Canada - National Science Library

    Sanchez-Garcia, Laura; Martín, Lucas; Mangues, Ramon; Ferrer-Miralles, Neus; Vázquez, Esther; Villaverde, Antonio

    2016-01-01

    .... As both protein extraction from natural producers and chemical synthesis undergo inherent constraints that limit regular large-scale production, recombinant DNA technologies have rapidly become...

  17. Chromosomal location of the genes encoding complement components C5 and factor H in the mouse

    DEFF Research Database (Denmark)

    D'Eustachio, P; Kristensen, Torsten; Wetsel, R A

    1986-01-01

    Complementary DNA probes corresponding to the factor H and C5 polypeptides have been used to determine the chromosomal localizations of these two complement components. Both probes revealed complex and polymorphic arrays of DNA fragments in Southern blot analysis of mouse genomic DNA. Following...... to chromosome 1 or chromosome 3. Following the inheritance of DNA restriction fragment-length polymorphisms revealed by the probes in recombinant inbred mouse strains allowed the factor H-associated fragments to be mapped to Sas-1 on chromosome 1, and the C5-associated fragments to be mapped to Hc. Analysis...... of three-point crosses, in turn, placed the latter locus 19 cM distal to Sd on chromosome 2. We have designated the two loci Cfh and C5, respectively. This genetic analysis raises the possibility that C5 and factor H are both encoded by complex loci composed of distinct structural and regulatory genes....

  18. Targeted integration in rat and mouse embryos with zinc-finger nucleases.

    Science.gov (United States)

    Cui, Xiaoxia; Ji, Diana; Fisher, Daniel A; Wu, Yumei; Briner, David M; Weinstein, Edward J

    2011-01-01

    Gene targeting is indispensible for reverse genetics and the generation of animal models of disease. The mouse has become the most commonly used animal model system owing to the success of embryonic stem cell-based targeting technology, whereas other mammalian species lack convenient tools for genome modification. Recently, microinjection of engineered zinc-finger nucleases (ZFNs) in embryos was used to generate gene knockouts in the rat and the mouse by introducing nonhomologous end joining (NHEJ)-mediated deletions or insertions at the target site. Here we use ZFN technology in embryos to introduce sequence-specific modifications (knock-ins) by means of homologous recombination in Sprague Dawley and Long-Evans hooded rats and FVB mice. This approach enables precise genome engineering to generate modifications such as point mutations, accurate insertions and deletions, and conditional knockouts and knock-ins. The same strategy can potentially be applied to many other species for which genetic engineering tools are needed.

  19. Production of recombinant scFv against p24 of human immunodeficiency virus type 1 by phage display technology.

    Science.gov (United States)

    Mohammadzadeh, Sara; Rajabibazl, Masoumeh; Fourozandeh, Mehdi; Rasaee, Mohammad Javad; Rahbarizadeh, Fatemeh; Mohammadi, Mohammad

    2014-02-01

    Phage display has a fundamental role in protein isolation and engineering. Isolated proteins produced with this method can be modified for specific binding and affinity. P24 is the most produced protein during human immune deficiency virus (HIV) replication; especially in the early steps of HIV-1 infection, its evaluation may have diagnostic values. To test the HIV-1 infection, p24 antigen assay appears to be a very promising alternative to RNA assays. In this study, we have generated a recombinant mouse single chain antibody fragment against p24 of the HIV-1 with the use of phage display technology. After isolation of antibody variable-region (V) gene of B cells extracted from the spleen of an immunized mouse, a library of single chain Fv fragments (scFv) was constructed. The library was used in a series of bio-panning processes against recombinant p24 protein expressed from Escherichia coli. The isolated scFv antibody specifically recognizes the HIV-1 capsid protein p24. The affinity constant of the isolated scFv antibody (MF85) was found to be 2×10(-9) M. Our studies showed that the MF85 scFV antibody has similar properties as that of monoclonal antibodies produced by the hybridoma technology.

  20. Recombinant α-actinin subunit antigens of Trichomonas vaginalis as potential vaccine candidates in protecting against trichomoniasis.

    Science.gov (United States)

    Xie, Yi-Ting; Gao, Jiang-Mei; Wu, Ya-Ping; Tang, Petrus; Hide, Geoff; Lai, De-Hua; Lun, Zhao-Rong

    2017-02-16

    Human trichomoniasis caused by Trichomonas vaginalis is one of the most common sexually transmitted diseases with more than 200 million cases worldwide. It has caused a series of health problems to patients. For prevention and control of infectious diseases, vaccines are usually considered as one of the most cost-efficient tools. However, until now, work on the development of T. vaginalis vaccines is still mainly focused on the screening of potential immunogens. Alpha-actinin characterized by high immunogenicity in T. vaginalis was suggested as a promising candidate. Therefore, the purpose of this study was to evaluate the protective potency of recombinant α-actinin against T. vaginalis infection in a mouse intraperitoneal model. Two selected coding regions of α-actinin (ACT-F, 14-469 aa and ACT-T, 462-844 aa) amplified from cDNA were cloned into pET-32a (+) expression vector and transfected into BL21 cells. After induction with IPTG and purification with electroelution, the two recombinant fusion proteins were emulsified in Freund's adjuvant (FA) and used to immunize BALB/C mice. Following intraperitoneal inoculation with T. vaginalis, the survival rate of mice was monitored for the assessment of protective potency. After immunization, the antibody level in mouse serum was assessed by ELISA, splenocyte proliferation response was detected with CCK8 and cytokines in the supernatant of splenocytes were quantified with a cytometric bead-based assay. We successfully obtained purified ACT-F (70.33 kDa) and ACT-T (61.7kDa). Both recombinant proteins could provide significant protection against T. vaginalis challenge, especially ACT-T (with 100% protection within one month). Meanwhile, high levels of specific total IgG and subtypes (IgG1 > IgG2a) were detected in sera from the immunized mice. Our results also revealed a statistically significant increase in splenocyte proliferation and related cytokine (IFN-γ, IL-6, IL-17A and IL-10) production after repeated

  1. Construction of a mouse model of factor VIII deficiency by gene targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bi, L.; Lawler, A.; Gearhart, J. [Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States)] [and others

    1994-09-01

    To develop a small animal model of hemophilia A for gene therapy experiments, we set out to construct a mouse model for factor VIII deficiency by gene targeting. First, we screened a mouse liver cDNA library using a human FVIII cDNA probe. We cloned a 2.6 Kb partial mouse factor VIII cDNA which extends from 800 base pairs of the 3{prime} end of exon 14 to the 5{prime} end of exon 26. A mouse genomic library made from strain 129 was then screened to obtain genomic fragments covering the exons desired for homologous recombination. Two genomic clones were obtained, and one covering exon 15 through 22 was used for gene targeting. To make gene targeting constructs, a 5.8 Kb genomic DNA fragment covering exons 15 to 19 of the mouse FVIII gene was subcloned, and the neo expression cassette was inserted into exons 16 and 17 separately by different strategies. These two constructs were named MFVIIIC-16 and MFVIIIC-17. The constructs were linearized and transfected into strain 129 mouse ES cells by electroporation. Factor VIII gene-knockout ES cell lines were selected by G-418 and screened by genomic Southern blots. Eight exon 16 targeted cell lines and five exon 17 targeted cell lines were obtained. Three cell lines from each construct were injected into blastocysts and surgically transferred into foster mothers. Multiple chimeric mice with 70-90% hair color derived from the ES-cell genotype were seen with both constructs. Germ line transmission of the ES-cell genotype has been obtained for the MFVIIIC-16 construct, and multiple hemophilia A carrier females have been identified. Factor VIII-deficient males will be conceived soon.

  2. The role of retrotransposons in gene family expansions: insights from the mouse Abp gene family.

    Science.gov (United States)

    Janoušek, Václav; Karn, Robert C; Laukaitis, Christina M

    2013-05-29

    Retrotransposons have been suggested to provide a substrate for non-allelic homologous recombination (NAHR) and thereby promote gene family expansion. Their precise role, however, is controversial. Here we ask whether retrotransposons contributed to the recent expansions of the Androgen-binding protein (Abp) gene families that occurred independently in the mouse and rat genomes. Using dot plot analysis, we found that the most recent duplication in the Abp region of the mouse genome is flanked by L1Md_T elements. Analysis of the sequence of these elements revealed breakpoints that are the relicts of the recombination that caused the duplication, confirming that the duplication arose as a result of NAHR using L1 elements as substrates. L1 and ERVII retrotransposons are considerably denser in the Abp regions than in one Mb flanking regions, while other repeat types are depleted in the Abp regions compared to flanking regions. L1 retrotransposons preferentially accumulated in the Abp gene regions after lineage separation and roughly followed the pattern of Abp gene expansion. By contrast, the proportion of shared vs. lineage-specific ERVII repeats in the Abp region resembles the rest of the genome. We confirmed the role of L1 repeats in Abp gene duplication with the identification of recombinant L1Md_T elements at the edges of the most recent mouse Abp gene duplication. High densities of L1 and ERVII repeats were found in the Abp gene region with abrupt transitions at the region boundaries, suggesting that their higher densities are tightly associated with Abp gene duplication. We observed that the major accumulation of L1 elements occurred after the split of the mouse and rat lineages and that there is a striking overlap between the timing of L1 accumulation and expansion of the Abp gene family in the mouse genome. Establishing a link between the accumulation of L1 elements and the expansion of the Abp gene family and identification of an NAHR-related breakpoint in

  3. Establishment of a transgenic mouse model of corneal dystrophy overexpressing human BIGH3.

    Science.gov (United States)

    Liao, Xin; Cui, Hongping; Wang, Fang

    2013-11-01

    This study aimed to establish a transgenic mouse model of corneal dystrophy (CD) overexpressing the human transforming growth factor, β-induced, 68 kDa (TGFBI, also known as BIGH3) gene. A purified and linearized recombinant plasmid carrying the expression cassette BIGH3‑IRES‑EGFP was microinjected into the pronuclei of C57BL/6J mouse fertilized eggs under the control of the phosphoglycerate kinase (PGK) promoter. The expression of human BIGH3 in the transgenic mice was confirmed by PCR using DNA extracted from tail tissue. Four founder transgenic mice were identified by PCR and the increased expression of BIGH3 was observed in the corneas of the transgenic mice by RT-PCR and western blot analysis. The abnormal corneas with central opacity were observed in the transgenic mice by corneal photography. We concluded that the exogenous gene, BIGH3, was integrated successfully into the mouse genome through microinjection. In addition, the phenotype observed in this BIGH3 transgenic mouse model was similar to CD. Therefore, this transgenic model may prove useful in the investigation of the pathogenesis of CD.

  4. Effective gene editing by high-fidelity base editor 2 in mouse zygotes

    Directory of Open Access Journals (Sweden)

    Puping Liang

    2017-06-01

    Full Text Available ABSTRACT Targeted point mutagenesis through homologous recombination has been widely used in genetic studies and holds considerable promise for repairing disease-causing mutations in patients. However, problems such as mosaicism and low mutagenesis efficiency continue to pose challenges to clinical application of such approaches. Recently, a base editor (BE system built on cytidine (C deaminase and CRISPR/Cas9 technology was developed as an alternative method for targeted point mutagenesis in plant, yeast, and human cells. Base editors convert C in the deamination window to thymidine (T efficiently, however, it remains unclear whether targeted base editing in mouse embryos is feasible. In this report, we generated a modified high-fidelity version of base editor 2 (HF2-BE2, and investigated its base editing efficacy in mouse embryos. We found that HF2-BE2 could convert C to T efficiently, with up to 100% biallelic mutation efficiency in mouse embryos. Unlike BE3, HF2-BE2 could convert C to T on both the target and non-target strand, expanding the editing scope of base editors. Surprisingly, we found HF2-BE2 could also deaminate C that was proximal to the gRNA-binding region. Taken together, our work demonstrates the feasibility of generating point mutations in mouse by base editing, and underscores the need to carefully optimize base editing systems in order to eliminate proximal-site deamination.

  5. Recombination of Globally Circulating Varicella-Zoster Virus.

    Science.gov (United States)

    Norberg, Peter; Depledge, Daniel P; Kundu, Samit; Atkinson, Claire; Brown, Julianne; Haque, Tanzina; Hussaini, Yusuf; MacMahon, Eithne; Molyneaux, Pamela; Papaevangelou, Vassiliki; Sengupta, Nitu; Koay, Evelyn S C; Tang, Julian W; Underhill, Gillian S; Grahn, Anna; Studahl, Marie; Breuer, Judith; Bergström, Tomas

    2015-07-01

    Varicella-zoster virus (VZV) is a human herpesvirus, which during primary infection typically causes varicella (chicken pox) and establishes lifelong latency in sensory and autonomic ganglia. Later in life, the virus may reactivate to cause herpes zoster (HZ; also known as shingles). To prevent these diseases, a live-attenuated heterogeneous vaccine preparation, vOka, is used routinely in many countries worldwide. Recent studies of another alphaherpes virus, infectious laryngotracheitis virus, demonstrate that live-attenuated vaccine strains can recombine in vivo, creating virulent progeny. These findings raised concerns about using attenuated herpesvirus vaccines under conditions that favor recombination. To investigate whether VZV may undergo recombination, which is a prerequisite for VZV vaccination to create such conditions, we here analyzed 115 complete VZV genomes. Our results demonstrate that recombination occurs frequently for VZV. It thus seems that VZV is fully capable of recombination if given the opportunity, which may have important implications for continued VZV vaccination. Although no interclade vaccine wild-type recombinant strains were found, intraclade recombinants were frequently detected in clade 2, which harbors the vaccine strains, suggesting that the vaccine strains have already been involved in recombination events, either in vivo or in vitro during passages in cell culture. Finally, previous partial and complete genomic studies have described strains that do not cluster phylogenetically to any of the five established clades. The additional VZV strains sequenced here, in combination with those previously published, have enabled us to formally define a novel sixth VZV clade. Although genetic recombination has been demonstrated to frequently occur for other human alphaherpesviruses, herpes simplex viruses 1 and 2, only a few ancient and isolated recent recombination events have hitherto been demonstrated for VZV. In the present study, we

  6. New recombinant serotypes of AAV vectors.

    Science.gov (United States)

    Gao, Guangping; Vandenberghe, Luk H; Wilson, James M

    2005-06-01

    AAV based vectors can achieve stable gene transfer with minimal vector related toxicities. AAV serotype 2 (AAV2) is the first AAV that was vectored for gene transfer applications. However, the restricted tissue tropism of AAV and its low transduction efficiency have limited its further development as vector. Recent studies using vectors derived from alternative AAV serotypes such as AAV1, 4, 5 and 6 have shown improved potency and broadened tropism of the AAV vector by packaging the same vector genome with different AAV capsids. In an attempt to search for potent AAV vectors with enhanced performance profiles, molecular techniques were employed for the detection and isolation of endogenous AAVs from a variety of human and non-human primate (NHP) tissues. A family of novel primate AAVs consisting of 110 non-redundant species of proviral sequences was discovered and turned to be prevalent in 18-19% of the tissues evaluated. Phylogenetic and functional analyses revealed that primate AAVs are segregated into clades based on phylogenetic relatedness. The members within a clade share functional and serological properties. Initial evaluation in mouse models of vectors based on these novel AAVs for tissue tropism and gene transfer potency led to the identification of some vector with improved gene transfer to different target tissues. Gene therapy treatment of several mouse and canine models with novel AAV vectors achieved long term phenotypic corrections. Vectors based on new primate AAVs could become the next generation of efficient gene transfer vehicles for various gene therapy applications.

  7. Solution structure and DNA-binding properties of the winged helix domain of the meiotic recombination HOP2 protein.

    Science.gov (United States)

    Moktan, Hem; Guiraldelli, Michel F; Eyster, Craig A; Zhao, Weixing; Lee, Chih-Ying; Mather, Timothy; Camerini-Otero, R Daniel; Sung, Patrick; Zhou, Donghua H; Pezza, Roberto J

    2014-05-23

    The HOP2 protein is required for efficient double-strand break repair which ensures the proper synapsis of homologous chromosomes and normal meiotic progression. We previously showed that in vitro HOP2 shows two distinctive activities: when it is incorporated into a HOP2-MND1 heterodimer, it stimulates DMC1 and RAD51 recombination activities, and the purified HOP2 alone is proficient in promoting strand invasion. The structural and biochemical basis of HOP2 action in recombination are poorly understood; therefore, they are the focus of this work. Herein, we present the solution structure of the amino-terminal portion of mouse HOP2, which contains a typical winged helix DNA-binding domain. Together with NMR spectral changes in the presence of double-stranded DNA, protein docking on DNA, and mutation analysis to identify the amino acids involved in DNA coordination, our results on the three-dimensional structure of HOP2 provide key information on the fundamental structural and biochemical requirements directing the interaction of HOP2 with DNA. These results, in combination with mutational experiments showing the role of a coiled-coil structural feature involved in HOP2 self-association, allow us to explain important aspects of the function of HOP2 in recombination. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Expression and purification of a new recombinant camel hepcidin able to promote the degradation of the iron exporter ferroportin1.

    Science.gov (United States)

    Boumaiza, Mohamed; Jaouen, Maryse; Deschemin, Jean-Christophe; Ezzine, Aymen; Ben Khalaf, Noureddine; Vaulont, Sophie; Marzouki, Mohamed Nèjib; Sari, Marie Agnès

    2015-11-01

    Hepcidin, a 25-amino-acid and highly disulfide bonded antimicrobial peptide, is the central regulator of iron homeostasis. This hormone is expressed in response to iron and inflammation and interacts with ferroportin1 (FPN1), the only known iron exporter in vertebrates, inducing its internalization and degradation. Thus, the export of iron from cells to plasma will be significantly diminished. Thereby, hepcidin has become the target of intense research studies due to its profound biomedical significance. This study describes the functional expression of recombinant camel hepcidin in Escherichia coli. Biologically active recombinant camel hepcidin was obtained thanks to the production of a hepcidin-thioredoxin fusion protein (TRX-HepcD) and a purified camel hepcidin, with an extra methionine at the N-terminus, was obtained after enterokinase cleavage of the fusion protein. Presence of the four disulfide bridges was verified using MALDI-ToF spectrometry. The recombinant camel hepcidin was compared to related synthetic bioactive peptides, including human hepcidin, and was found equally able to promote ferroportin degradation of mouse macrophages. Furthermore, camel hepcidins exhibits a high capacity to inhibit the growth of Leishmania major promastigotes. These results proved that production of functional camel hepcidin can be achieved in E. coli, this is a major interest for the production of cysteine rich peptides or proteins that can be purified under their functional form without the need of a refolding process. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Induction of leukemia cell differentiation and apoptosis by recombinant P48, a modulin derived from Mycoplasma fermentans.

    Science.gov (United States)

    Hall, R E; Agarwal, S; Kestler, D P

    2000-03-05

    P48 is a 48-kDa monocytic differentiation/activation factor which was originally identified in the conditioned medium of the Reh and other leukemia cell lines and has recently been shown to be a Mycoplasma fermentans gene product. Previously, conditioned medium P48 has been shown to induce differentiation of HL-60 (human promyelocytic leukemia) cells. Recently our laboratory isolated cDNA clones for P48 from Reh cells and genomic clones from Mycoplasma fermentans and expressed the recombinant protein as a maltose binding protein (MBP) fusion protein in E. coli. In this report we present the initial characterization of this recombinant P48 fusion protein (rP48-MBP). We show that rP48-MBP induces differentiation of HL-60, U937 (human histiocytic lymphoma), and M1 (mouse myeloid leukemia) cell lines. Interestingly, rP48-MBP also induces apoptosis of U937 and HL-60 cells as assessed by terminal transferase (TUNEL) assays. This is the first report of induction of apoptosis by a Mycoplasma gene product. P48 is a Mycoplasma-derived immunomodulatory molecule which has differentiation and apoptosis-inducing activities and may be important in the pathophysiology of Mycoplasma infections. The recombinant protein may be useful in studying the mechanisms of differentiation, cytokine production, and apoptosis in malignant and nonmalignant hematopoietic cells. Copyright 2000 Academic Press.

  10. BRIT1/MCPH1 is essential for mitotic and meiotic recombination DNA repair and maintaining genomic stability in mice.

    Directory of Open Access Journals (Sweden)

    Yulong Liang

    2010-01-01

    Full Text Available BRIT1 protein (also known as MCPH1 contains 3 BRCT domains which are conserved in BRCA1, BRCA2, and other important molecules involved in DNA damage signaling, DNA repair, and tumor suppression. BRIT1 mutations or aberrant expression are found in primary microcephaly patients as well as in cancer patients. Recent in vitro studies suggest that BRIT1/MCPH1 functions as a novel key regulator in the DNA damage response pathways. To investigate its physiological role and dissect the underlying mechanisms, we generated BRIT1(-/- mice and identified its essential roles in mitotic and meiotic recombination DNA repair and in maintaining genomic stability. Both BRIT1(-/- mice and mouse embryonic fibroblasts (MEFs were hypersensitive to gamma-irradiation. BRIT1(-/- MEFs and T lymphocytes exhibited severe chromatid breaks and reduced RAD51 foci formation after irradiation. Notably, BRIT1(-/- mice were infertile and meiotic homologous recombination was impaired. BRIT1-deficient spermatocytes exhibited a failure of chromosomal synapsis, and meiosis was arrested at late zygotene of prophase I accompanied by apoptosis. In mutant spermatocytes, DNA double-strand breaks (DSBs were formed, but localization of RAD51 or BRCA2 to meiotic chromosomes was severely impaired. In addition, we found that BRIT1 could bind to RAD51/BRCA2 complexes and that, in the absence of BRIT1, recruitment of RAD51 and BRCA2 to chromatin was reduced while their protein levels were not altered, indicating that BRIT1 is involved in mediating recruitment of RAD51/BRCA2 to the damage site. Collectively, our BRIT1-null mouse model demonstrates that BRIT1 is essential for maintaining genomic stability in vivo to protect the hosts from both programmed and irradiation-induced DNA damages, and its depletion causes a failure in both mitotic and meiotic recombination DNA repair via impairing RAD51/BRCA2's function and as a result leads to infertility and genomic instability in mice.

  11. Recombinant expression of Chlamydia trachomatis major outer membrane protein in E. Coli outer membrane as a substrate for vaccine research.

    Science.gov (United States)

    Wen, Zhiyun; Boddicker, Melissa A; Kaufhold, Robin M; Khandelwal, Puneet; Durr, Eberhard; Qiu, Ping; Lucas, Bob J; Nahas, Debbie D; Cook, James C; Touch, Sinoeun; Skinner, Julie M; Espeseth, Amy S; Przysiecki, Craig T; Zhang, Lan

    2016-07-27

    Chlamydia trachomatis is a human pathogen which causes a number of pathologies, including genital tract infections in women that can result in tubal infertility. Prevention of infection and disease control might be achieved through vaccination; however, a safe, efficacious and cost-effective vaccine against C. trachomatis infection remains an unmet medical need. C. trachomatis major outer membrane protein (MOMP), a β-barrel integral outer membrane protein, is the most abundant antigen in the outer membrane of the bacterium and has been evaluated as a subunit vaccine candidate. Recombinant MOMP (rMOMP) expressed in E. coli cytoplasm forms inclusion bodies and rMOMP extracted from inclusion bodies results in a reduced level of protection compared to the native MOMP in a mouse challenge model. We sought to target the recombinant expression of MOMP to the E. coli outer membrane (OM). Successful surface expression was achieved with codon harmonization, utilization of low copy number vectors and promoters with moderate strength, suitable leader sequences and optimization of cell culture conditions. rMOMP was extracted from E. coli outer membrane, purified, and characterized biophysically. The OM expressed and purified rMOMP is immunogenic in mice and elicits antibodies that react to the native antigen, Chlamydia elementary body (EB). C. trachomatis MOMP was functionally expressed on the surface of E. coli outer membrane. The OM expressed and purified rMOMP elicits antibodies that react to the native antigen, Chlamydia EB, in a mouse immunogenicity model. Surface expression of MOMP could provide useful reagents for vaccine research, and the methodology could serve as a platform to produce other outer membrane proteins recombinantly.

  12. Mycoviruses, RNA silencing, and viral RNA recombination.

    Science.gov (United States)

    Nuss, Donald L

    2011-01-01

    In contrast to viruses of plants and animals, viruses of fungi, mycoviruses, uniformly lack an extracellular phase to their replication cycle. The persistent, intracellular nature of the mycovirus life cycle presents technical challenges to experimental design. However, these properties, coupled with the relative simplicity and evolutionary position of the fungal host, also provide opportunities for examining fundamental aspects of virus-host interactions from a perspective that is quite different from that pertaining for most plant and animal virus infections. This chapter presents support for this view by describing recent advances in the understanding of antiviral defense responses against one group of mycoviruses for which many of the technical experimental challenges have been overcome, the hypoviruses responsible for hypovirulence of the chestnut blight fungus Cryphonectria parasitica. The findings reveal new insights into the induction and suppression of RNA silencing as an antiviral defense response and an unexpected role for RNA silencing in viral RNA recombination. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Omenn Syndrome and DNA recombination defects.

    Science.gov (United States)

    Yachie, Akihiro

    2017-01-01

    Mutations in the RAG1/RAG2 genes are associated with a broad spectrum of clinical phenotypes, ranging from severe combined immunodeficiency to various autoimmune diseases. The diversity of the clinical symptoms is determined not only by the residual RAG recombinase enzyme activity as determined by the mutations, but also by multiple environmental factors and, in rare cases, by second site mutations within the RAG1/RAG2 genes. The residual recombinase activity is responsible for the oligoclonal expansion of autoreactive T cells. Omenn syndrome is the result of intense Th2 type inflammation involving the skin and multiple other organs triggered by these T cells. In this review, the molecular pathology of diseases caused by RAG1/RAG2 mutations, in particular Omenn syndrome, will be discussed. Furthermore, abnormalities in other molecules involved in V(D)J recombination will be discussed in relation to Omenn-like syndrome.

  14. A recombinant wheat serpin with inhibitory activity

    DEFF Research Database (Denmark)

    Rasmussen, Søren K; Dahl, Søren Weis; Nørgård, Anette

    1996-01-01

    to the subfamily of protein Z-type serpins and the amino acid sequence is 70%, identical with the barley serpins BSZ4 and BSZx and 27-33% identical with human serpins such as alpha(1)-proteinase inhibitor, antithrombin III, and plasminogen activator inhibitor. The cDNA was subcloned in the pET3d expression vector......, equipped with a histidine affinity tag at the N-terminus and expressed in Escherichia coli BL(21) DE3 pLysS. Recombinant WSZ1 from the soluble fraction was partially purified on Ni-NTA agarose and MonoQ columns and shown to form SDS-stable complexes with sc-chymotrypsin. Southern blots and amino acid...... sequencing indicated that only few serpins are encoded by wheat, but at least three distinct genes are expressed in the grain. Cleavage experiments on a chymotrypsin column suggested a Gln-Gln reactive site bond not previously observed in inhibitory serpins....

  15. Nonequilibrium recombination after a curved shock wave

    Science.gov (United States)

    Wen, Chihyung; Hornung, Hans

    2010-02-01

    The effect of nonequilibrium recombination after a curved two-dimensional shock wave in a hypervelocity dissociating flow of an inviscid Lighthill-Freeman gas is considered. An analytical solution is obtained with the effective shock values derived by Hornung (1976) [5] and the assumption that the flow is ‘quasi-frozen’ after a thin dissociating layer near the shock. The solution gives the expression of dissociation fraction as a function of temperature on a streamline. A rule of thumb can then be provided to check the validity of binary scaling for experimental conditions and a tool to determine the limiting streamline that delineates the validity zone of binary scaling. The effects on the nonequilibrium chemical reaction of the large difference in free stream temperature between free-piston shock tunnel and equivalent flight conditions are discussed. Numerical examples are presented and the results are compared with solutions obtained with two-dimensional Euler equations using the code of Candler (1988) [10].

  16. Initiation of Meiotic Recombination in Mammals

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2010-12-01

    Full Text Available Meiotic recombination is initiated by the induction of programmed DNA double strand breaks (DSBs. DSB repair promotes homologous interactions and pairing and leads to the formation of crossovers (COs, which are required for the proper reductional segregation at the first meiotic division. In mammals, several hundred DSBs are generated at the beginning of meiotic prophase by the catalytic activity of SPO11. Currently it is not well understood how the frequency and timing of DSB formation and their localization are regulated. Several approaches in humans and mice have provided an extensive description of the localization of initiation events based on CO mapping, leading to the identification and characterization of preferred sites (hotspots of initiation. This review presents the current knowledge about the proteins known to be involved in this process, the sites where initiation takes place, and the factors that control hotspot localization.

  17. Mouse models for methylmalonic aciduria.

    Directory of Open Access Journals (Sweden)

    Heidi L Peters

    Full Text Available Methylmalonic aciduria (MMA is a disorder of organic acid metabolism resulting from a functional defect of methylmalonyl-CoA mutase (MCM. MMA is associated with significant morbidity and mortality, thus therapies are necessary to help improve quality of life and prevent renal and neurological complications. Transgenic mice carrying an intact human MCM locus have been produced. Four separate transgenic lines were established and characterised as carrying two, four, five or six copies of the transgene in a single integration site. Transgenic mice from the 2-copy line were crossed with heterozygous knockout MCM mice to generate mice hemizygous for the human transgene on a homozygous knockout background. Partial rescue of the uniform neonatal lethality seen in homozygous knockout mice was observed. These rescued mice were significantly smaller than control littermates (mice with mouse MCM gene. Biochemically, these partial rescue mice exhibited elevated methylmalonic acid levels in urine, plasma, kidney, liver and brain tissue. Acylcarnitine analysis of blood spots revealed elevated propionylcarnitine levels. Analysis of mRNA expression confirms the human transgene is expressed at higher levels than observed for the wild type, with highest expression in the kidney followed closely by brain and liver. Partial rescue mouse fibroblast cultures had only 20% of the wild type MCM enzyme activity. It is anticipated that this humanised partial rescue mouse model of MMA will enable evaluation of long-term pathophysiological effects of elevated methylmalonic acid levels and be a valuable model for the investigation of therapeutic strategies, such as cell transplantation.

  18. Mouse Models of Gastric Cancer

    Science.gov (United States)

    Hayakawa, Yoku; Fox, James G.; Gonda, Tamas; Worthley, Daniel L.; Muthupalani, Sureshkumar; Wang, Timothy C.

    2013-01-01

    Animal models have greatly enriched our understanding of the molecular mechanisms of numerous types of cancers. Gastric cancer is one of the most common cancers worldwide, with a poor prognosis and high incidence of drug-resistance. However, most inbred strains of mice have proven resistant to gastric carcinogenesis. To establish useful models which mimic human gastric cancer phenotypes, investigators have utilized animals infected with Helicobacter species and treated with carcinogens. In addition, by exploiting genetic engineering, a variety of transgenic and knockout mouse models of gastric cancer have emerged, such as INS-GAS mice and TFF1 knockout mice. Investigators have used the combination of carcinogens and gene alteration to accelerate gastric cancer development, but rarely do mouse models show an aggressive and metastatic gastric cancer phenotype that could be relevant to preclinical studies, which may require more specific targeting of gastric progenitor cells. Here, we review current gastric carcinogenesis mouse models and provide our future perspectives on this field. PMID:24216700

  19. Genetic variation and recombination in Aichi virus.

    Science.gov (United States)

    Lukashev, Alexander N; Drexler, Jan Felix; Belalov, Ilya S; Eschbach-Bludau, Monika; Baumgarte, Sigrid; Drosten, Christian

    2012-06-01

    Aichi virus (AiV), a member of the genus Kobuvirus in the family Picornaviridae, causes gastroenteritis in humans. It was noted that AiV differs from other picornaviruses in its unusually high C content and a very high degree of genome-ordered RNA secondary structures. However, the genetic variability and mutational restrictions on a full-genome scale have not been studied. In addition to the available five complete AiV genomes, we determined here another five complete coding sequences of AiV sampled in Germany, 2004. Distinctive AiV genetic features included a low incidence of recombination along the genome without obvious hotspots or spared regions and very low rates of synonymous and non-synonymous variation, supporting an absence of AiV serotypes. In addition, the absence of recombination between AiV genotypes A and B suggested the existence of reproductive isolation between taxonomic units below the species level. In contrast to most other picornaviruses, AiV genomes strongly avoided the UpA dinucleotide, while there was no obvious selection against the CpG dinucleotide. AiV genomes also appeared to contain a codon usage bias (CUB) apparent as an effective number of codons of 39.5, which was amongst the most extreme among RNA viruses. A set of sequence scrambling algorithms was developed to determine the origin of CUB in AiV. While in most picornaviruses the genomic dinucleotide content contributed significantly to CUB, in AiV its extreme nucleotide content, i.e. 57 % third codon position C, was the main driving force behind the apparent CUB.

  20. Functional, Responsive Materials Assembled from Recombinant Oleosin

    Science.gov (United States)

    Hammer, Daniel

    Biological cells are surrounded by a plasma membrane made primarily of phospholipids that form a bilayer. This membrane is permselective and compartmentalizes the cell. A simple form of artificial cell is the vesicle, in which a phospholipid bilayer membrane surrounds an aqueous solution. However, there is no a priori reason why a membrane needs to be made of phospholipids. It could be made of any surfactant that forms a bilayer. We have assembled membranes and other structures from the recombinant plant protein oleosin. The ability to assemble from a recombinant protein means that every molecule is identical, we have complete control over the sequence, and hence can build in designer functionality with high fidelity, including adhesion and enzymatic activity. Such incorporation is trivial using the tools of molecular biology. We find that while many variants of oleosin make membranes, others make micelles and sheets. We show how the type of supramolecular structure can be altered by the conditions of solvent, such as ionic strength, and the architecture of the surfactant itself. We show that protease cleavable domains can be incorporated within oleosin, and be engineered to protect other functional domains such as adhesive motifs, to make responsive materials whose activity and shape depend on the action of proteases. We will also present the idea of making ``Franken''-oleosins, where large domains of native oleosin are replaced with domains from other functional proteins, to make hybrids conferred by the donor protein. Thus, we can view oleosin as a template upon which a vast array of designer functionalities can be imparted..

  1. Practical Application of Microelectroporation into Developing Mouse Brain

    Science.gov (United States)

    Shimogori, Tomomi; Ogawa, Masaharu

    One key approach toward understanding the genetic mechanisms underlying embryonic development involves the overexpression or misexpression of target genes in specific regions and at specific time points. The mouse gene-knockout system has been used extensively for loss-of-function studies due to the availability of a large number of mutant lines and the technical advantages of this system. In contrast, gain-of-function analyses have been performed through the production of knock-in and transgenic animals and with the use of various viruses (Cornetta 2006; Jakobsson et al., 2003; Hashimoto and Mikoshiba, 2004). However, it is not always possible to express or suppress genes in a spatially and temporally restricted manner, and the generation of genetically modified mice and recombinant viruses is time consuming and labor intensive. With the aim of solving these problems, many attempts have been made to apply the electroporation technique in research on developmental biology. Due to the accessibility of the avian embryo, it has been used as a classic model system for the study of developmental events in vertebrates. A novel technique for successful gene delivery into chick embryos has been established; this technique is known as in ovo electroporation and appears to be an excellent method, permitting quick and direct examination of the function of the delivered genes (Muramatsu et al., 1997; Itasaki et al., 1999; Momose et al., 1999; Nakamura et al., 2000; Yasuda et al., 2000). It seems that this technique can be adapted to the mouse embryo and would permit more rapid functional analysis of genes than is achieved by the generation of knockout or transgenic mouse lines. However, the inaccessibility of embryos in the mammalian uterus renders in utero manipulations targeting precise regions difficult or impossible at most stages of development. Efforts have been undertaken by various researchers to establish an in utero electroporation system, and there have been several

  2. CFP10: mFcγ2 as a novel tuberculosis vaccine candidate increases immune response in mouse.

    Science.gov (United States)

    Baghani, Ali Asghar; Soleimanpour, Saman; Farsiani, Hadi; Mosavat, Arman; Yousefi, Masoud; Meshkat, Zahra; Rezaee, Seyed Abdolrahim; Jamehdar, Saeid Amel; Eydgahi, Mohammad Reza Akbari; Sadeghian, Hamid; Ghazvini, Kiarash

    2017-02-01

    Despite treatment with antibiotics and vaccination with BCG, tuberculosis (TB) is still considered as one of the most important public health problems in the world. Therefore, designing and producing a more effective vaccine against TB seems urgently. In this study, immunogenicity of a fusion protein which consisting or comprising CFP-10 from Mycobacterium tuberculosis and the Fc-domain of mouse IgG2a was evaluated as a novel subunit vaccine candidate against TB. The genetic constructs were cloned in pPICZαA expression vector and recombinant vectors (pPICZαA-CFP-10: Fcγ2a and pPICZαA-CFP-10:His) were transformed into Pichia pastoris. To evaluate the expression of recombinant proteins, SDS-PAGE and immunoblotting were used. The immunogenicity of recombinant proteins, with and without BCG were assessed in BALB/c mice and specific cytokines against recombinant proteins (IFN-γ, IL-12, IL-4, IL-17 and TGF-β) were evaluated. The levels of IFN-γ and IL-12 in mice that received recombinant proteins was higher than the control groups (BCG and PBS). Thus, both recombinant proteins (CFP-10:Fcγ2a and CFP-10:His) could excite good response in Th1-cells. The Fc-tagged protein had a stronger Th1 response with low levels of IL-4, as compared to CFP-10:His. However, the highest level of Th1 response was observed in groups that were vaccinated with BCG (prime) and then received recombinant protein CFP-10: Fcγ2a (booster). The results demonstrated that binding mice Fc-domain to CFP-10 protein can increase the immunogenicity of the subunit vaccine. Further studies, might be able to design and produce a new generation of subunit vaccines based on the Fc-fused immunogen.

  3. Trap-assisted recombination in disordered organic semiconductors

    NARCIS (Netherlands)

    Kuik, M.; Koster, L.J.A.; Wetzelaer, G.A.H.; Blom, P.W.M.

    2011-01-01

    The trap-assisted recombination of electrons and holes in organic semiconductors is investigated. The extracted capture coefficients of the trap-assisted recombination process are thermally activated with an identical activation energy as measured for the hole mobility μp. We demonstrate that the

  4. Expression and purification of recombinant hemoglobin in Escherichia coli

    DEFF Research Database (Denmark)

    Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

    2011-01-01

    BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...

  5. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector.

  6. Recombination-Driven Genome Evolution and Stability of Bacterial Species.

    Science.gov (United States)

    Dixit, Purushottam D; Pang, Tin Yau; Maslov, Sergei

    2017-09-01

    While bacteria divide clonally, horizontal gene transfer followed by homologous recombination is now recognized as an important contributor to their evolution. However, the details of how the competition between clonality and recombination shapes genome diversity remains poorly understood. Using a computational model, we find two principal regimes in bacterial evolution and identify two composite parameters that dictate the evolutionary fate of bacterial species. In the divergent regime, characterized by either a low recombination frequency or strict barriers to recombination, cohesion due to recombination is not sufficient to overcome the mutational drift. As a consequence, the divergence between pairs of genomes in the population steadily increases in the course of their evolution. The species lacks genetic coherence with sexually isolated clonal subpopulations continuously formed and dissolved. In contrast, in the metastable regime, characterized by a high recombination frequency combined with low barriers to recombination, genomes continuously recombine with the rest of the population. The population remains genetically cohesive and temporally stable. Notably, the transition between these two regimes can be affected by relatively small changes in evolutionary parameters. Using the Multi Locus Sequence Typing (MLST) data, we classify a number of bacterial species to be either the divergent or the metastable type. Generalizations of our framework to include selection, ecologically structured populations, and horizontal gene transfer of nonhomologous regions are discussed as well. Copyright © 2017 by the Genetics Society of America.

  7. Biophysical characterisation of GlycoPEGylated recombinant human factor VIIa

    DEFF Research Database (Denmark)

    Plesner, Bitten; Westh, Peter; Nielsen, Anders D.

    2011-01-01

    The effects of GlycoPEGylation on the structural, kinetic and thermal stability of recombinant human FVIIa were investigated using rFVIIa and linear 10 kDa and branched 40 kDa GlycoPEGylated® recombinant human FVIIa derivatives. The secondary and tertiary structure of rFVIIa measured by circular...

  8. Tailoring Charge Recombination in Photoelectrodes Using Oxide Nanostructures

    DEFF Research Database (Denmark)

    Iandolo, Beniamino; Wickman, Björn; Svensson, Elin

    2016-01-01

    Optimizing semiconductor devices for solar energy conversion requires an explicit control of the recombination of photogenerated electron−hole pairs. Here we show how the recombination of charge carriers can be controlled in semiconductor thin films by surface patterning with oxide nanodisks. The...

  9. Dynamic protein assemblies in homologous recombination with single DNA molecules

    NARCIS (Netherlands)

    van der Heijden, A.H.

    2007-01-01

    What happens when your DNA breaks? This thesis describes experimental work on the single-molecule level focusing on the interaction between DNA and DNA-repair proteins, in particular bacterial RecA and human Rad51, involved in homologous recombination. Homologous recombination and its central event

  10. Construction and Characterization of a Recombinant Invertebrate Iridovirus

    NARCIS (Netherlands)

    Ozgen, A.; Muratoglu, H.; Demirbag, Z.; Vlak, J.M.; Oers, van M.M.; Nalcacioglu, R.

    2014-01-01

    Chilo iridescent virus (CIV), officially named Insect iridescent virus 6 (IIV6), is the type species of the genus Iridovirus (family Iridoviridae). In this paper we constructed a recombinant CIV, encoding the green fluorescent protein (GFP). This recombinant can be used to investigate viral

  11. Biological Activities of Recombinant Liver X Receptor â- Ligand ...

    African Journals Online (AJOL)

    Purpose: To investigate tetracycline-inducible expression system for producing clinically usable, highquality liver X receptor ligand-binding domain recombinant protein. Methods: In this study, we have expressed and purified the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a tetracycline ...

  12. Collision and recombination driven instabilities in variable charged ...

    Indian Academy of Sciences (India)

    In line of this present situation our investigation revealed that the recombination is more important than dust-neutral collisions in laboratory plasma and fusion plasma, while the dust-neutral collision frequency is dominant in the interstellar plasmas. The effects of ion and dust densities and ion streaming on the recombination ...

  13. Homing of radiolabelled recombinant interleukin-2 activated natural ...

    Indian Academy of Sciences (India)

    Homing of radiolabelled recombinant interleukin-2 activated natural killer cells and their efficacy in adoptive immunotherapy against murine fibrosarcoma. Anuradha Rai Ashim K ... Keywords. Adoptive immunotherapy; ascitic fibrosarcoma; natural killer cells; non-recurrence of tumour; recombinant interleukin-2 activation ...

  14. On-line methanol sensor system development for recombinant ...

    African Journals Online (AJOL)

    This developed system was implemented for online methanol control in recombinant human serum albumin (rHSA) protein production by P. pastoris KM71 at methanol levels of 4 and 10 g/l with controlled fluctuations at 13.0 and 11.3% of oscillation, respectively. The accumulated amounts of recombinant protein from two ...

  15. Biological Activities of Recombinant Liver X Receptor β- Ligand ...

    African Journals Online (AJOL)

    Purpose: To investigate tetracycline-inducible expression system for producing clinically usable, high- quality liver X receptor ligand-binding domain recombinant protein. Methods: In this study, we have expressed and purified the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a tetracycline ...

  16. Co-solute assistance in refolding of recombinant proteins | Gerami ...

    African Journals Online (AJOL)

    Prokaryotic expression system is the most widely used host for the production of recombinant proteins but inclusion body formation is a major bottleneck in the production of recombinant proteins in prokaryotic cells, especially in Escherichia coli. In vitro refolding of inclusion body into the the proteins with native ...

  17. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    This study aimed at the generation of a stable transformed silkworm BmN cell line which can continuously express human interferon-λ2 (IFN-λ2) gene, and investigated the antiproliferative activity of this recombinant human IFN-λ2. Silkworm BmN cells were transfected with the recombinant vector pIZT/V5-His harboring the ...

  18. Recombination in Avian Gamma-Coronavirus Infectious Bronchitis Virus

    Directory of Open Access Journals (Sweden)

    Mark W. Jackwood

    2011-09-01

    Full Text Available Recombination in the family Coronaviridae has been well documented and is thought to be a contributing factor in the emergence and evolution of different coronaviral genotypes as well as different species of coronavirus. However, there are limited data available on the frequency and extent of recombination in coronaviruses in nature and particularly for the avian gamma-coronaviruses where only recently the emergence of a turkey coronavirus has been attributed solely to recombination. In this study, the full-length genomes of eight avian gamma-coronavirus infectious bronchitis virus (IBV isolates were sequenced and along with other full-length IBV genomes available from GenBank were analyzed for recombination. Evidence of recombination was found in every sequence analyzed and was distributed throughout the entire genome. Areas that have the highest occurrence of recombination are located in regions of the genome that code for nonstructural proteins 2, 3 and 16, and the structural spike glycoprotein. The extent of the recombination observed, suggests that this may be one of the principal mechanisms for generating genetic and antigenic diversity within IBV. These data indicate that reticulate evolutionary change due to recombination in IBV, likely plays a major role in the origin and adaptation of the virus leading to new genetic types and strains of the virus.

  19. Feasibility of a recombinant human apolipoprotein E reference material

    NARCIS (Netherlands)

    Schiele, F.; Barbier, A.; Visvikis, A.; Aggerbeck, L.; Rosseneu, M.; Havekes, L.; Huttinger, M.; Profilis, C.; Siest, G.

    1998-01-01

    The aim of this work was to prepare a recombinant apo E material and to determine its suitability as a reference material. We produced human apo E3 using recombinant DNA technology. The cDNA of human apo E3 was cloned in the pARHS bacterial expression vector and used to transfect E. Coli BL21 (DE3)

  20. Engineered mammalian cells for production of recombinant proteins

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to mammalian cells modified to provide for improved expression of a recombinant protein of interest. In particular, the invention relates to CHO cells and other host cells in which the expression of one or more endogenous secreted proteins has been disrupted, as well...... as to the preparation, identification and use of such cells in the production of recombinant proteins....

  1. Dynamics of HIV-1 recombination in its natural target cells.

    Science.gov (United States)

    Levy, David N; Aldrovandi, Grace M; Kutsch, Olaf; Shaw, George M

    2004-03-23

    Genetic recombination is believed to assist HIV-1 diversification and escape from host immunity and antiviral therapies, yet this process remains largely unexamined within the natural target-cell populations. We developed a method for measuring HIV-1 recombination directly that employs reporter viruses bearing functional enhanced yellow fluorescent protein (YFP) and enhanced cyan fluorescent protein (CFP) genes in which recombination produces a modified GFP gene and GFP fluorescence in the infected cells. These reporter viruses allow simultaneous quantification of the dynamics of HIV-1 infection, coinfection, and recombination in cell culture and in animal models by flow-cytometric analysis. Multiround infection assays revealed that productive cellular coinfection was subject to little functional inhibition. As a result, generation of recombinants proceeded according to the square of the infection rate during HIV-1 replication in T lymphocytes and within human thymic grafts in severe combined immunodeficient (SCID)-hu (Thy/Liv) mice. These results suggest that increases in viral load may confer a compounding risk of virus escape by means of recombinational diversification. A single round of replication in T lymphocytes in culture generated an average of nine recombination events per virus, and infection of macrophages led to approximately 30 crossover events, making HIV-1 up to an order of magnitude more recombinogenic than recognized previously and demonstrating that the infected cell exerts a profound influence on the frequency of recombination.

  2. Molecular cloning, sequencing and recombinant expression of a ...

    African Journals Online (AJOL)

    Recombinant 4D8 from the three tick species was expressed as a His-Tag fusion protein in Escherichia coli and the affinity-purified recombinant protein separated by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), then analyzed in immuno-blot analysis with anti-His-Tag antibody. A unique strong ...

  3. The generation-recombination theorem and noise in photoconductors

    NARCIS (Netherlands)

    Cook, J.G.; Blok, J.; Kampen, N.G. van

    1967-01-01

    The validity of the well-known generation-recombination (g-ν) theorem is examined for the case of noise in photoconductors. A master equation for the conditional probability of the level occupancies is set up in which the generation and recombination rates are functions of the incident light

  4. Sex recombination, and reproductive fitness: an experimental study using Paramecium

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, D.

    1982-08-01

    The effect of sex and recombination on reproductive fitness are measured using five wild stocks of Paramecium primaurelia. Among the wild stocks there were highly significant differences in growth rates. No hybrid had as low a fitness as the least fit parental stock. Recombination produced genotypes of higher fitness than those of either parent only in the cross between the two stocks of lowest fitness. The increase in variance of fitness as a result of recombination was almost exclusively attributable to the generation lines with low fitness. The fitness consequences of sexuality and mate choice were stock specific; some individuals leaving the most descendants by inbreeding, others by outcrossing. For most crosses the short-term advantage of sex, if any, accrue from the fusion of different gametes (hybrid vigor) and not from recombination. Since the homozygous genotype with the highest fitnes left the most progeny by inbreeding (no recombination), the persistence of conjugation in P. primaurelia is paradoxical. (JMT)

  5. Recombinant antithrombin: production and role in cardiovascular disorder.

    Science.gov (United States)

    Levy, J H; Weisinger, A; Ziomek, C A; Echelard, Y

    2001-08-01

    Plasma-derived antithrombin (AT) concentrates have been used for the management of hereditary and acquired deficiencies since the early 1980s. Recombinant versions of other blood factors and their derivatives are increasingly becoming available, providing a safe and abundant supply of these important therapeutics. However, the complexity of the AT molecule and the large doses often required for supplementation treatments preclude the use of traditional cell culture bioreactors for recombinant production. The development of a very efficient expression system has been necessary for the cost-efficient recombinant production of AT. Transgenic production, with its ability to yield high levels of heterologous protein and its scale-up flexibility, is an attractive alternative to plasma fractionation. Purification of recombinant AT from the milk of transgenic dairy goats has been developed to provide a homogeneous, well-defined, and abundant supply of this factor. This article describes the production of recombinant AT and aspects of clinical applications of this molecule to cardiovascular disorders.

  6. Optimal recombination in genetic algorithms for flowshop scheduling problems

    Science.gov (United States)

    Kovalenko, Julia

    2016-10-01

    The optimal recombination problem consists in finding the best possible offspring as a result of a recombination operator in a genetic algorithm, given two parent solutions. We prove NP-hardness of the optimal recombination for various variants of the flowshop scheduling problem with makespan criterion and criterion of maximum lateness. An algorithm for solving the optimal recombination problem for permutation flowshop problems is built, using enumeration of prefect matchings in a special bipartite graph. The algorithm is adopted for the classical flowshop scheduling problem and for the no-wait flowshop problem. It is shown that the optimal recombination problem for the permutation flowshop scheduling problem is solvable in polynomial time for almost all pairs of parent solutions as the number of jobs tends to infinity.

  7. Recombination Rate Evolution and the Origin of Species.

    Science.gov (United States)

    Ortiz-Barrientos, Daniel; Engelstädter, Jan; Rieseberg, Loren H

    2016-03-01

    A recipe for dissolving incipient species into a continuum of phenotypes is to recombine their genetic material. Therefore, students of speciation have become increasingly interested in the mechanisms by which recombination between locally adapted lineages is reduced. Evidence abounds that chromosomal rearrangements, via their suppression of recombination during meiosis in hybrids, play a major role in adaptation and speciation. By contrast, genic modifiers of recombination rates have been largely ignored in studies of speciation. We show how both types of reduction in recombination rates facilitate divergence in the face of gene flow, including the early stages of adaptive divergence, the persistence of species after secondary contact, and reinforcement. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Looking for the optimal rate of recombination for evolutionary dynamics

    Science.gov (United States)

    Saakian, David B.

    2018-01-01

    We consider many-site mutation-recombination models of evolution with selection. We are looking for situations where the recombination increases the mean fitness of the population, and there is an optimal recombination rate. We found two fitness landscapes supporting such nonmonotonic behavior of the mean fitness versus the recombination rate. The first case is related to the evolution near the error threshold on a neutral-network-like fitness landscape, for moderate genome lengths and large population. The more realistic case is the second one, in which we consider the evolutionary dynamics of a finite population on a rugged fitness landscape (the smooth fitness landscape plus some random contributions to the fitness). We also give the solution to the horizontal gene transfer model in the case of asymmetric mutations. To obtain nonmonotonic behavior for both mutation and recombination, we need a specially designed (ideal) fitness landscape.

  9. Charge carrier recombination dynamics in perovskite and polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paulke, Andreas; Kniepert, Juliane; Kurpiers, Jona; Wolff, Christian M.; Schön, Natalie; Brenner, Thomas J. K.; Neher, Dieter [Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24–25, 14476, Potsdam (Germany); Stranks, Samuel D. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Snaith, Henry J. [Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)

    2016-03-14

    Time-delayed collection field experiments are applied to planar organometal halide perovskite (CH{sub 3}NH{sub 3}PbI{sub 3}) based solar cells to investigate charge carrier recombination in a fully working solar cell at the nanosecond to microsecond time scale. Recombination of mobile (extractable) charges is shown to follow second-order recombination dynamics for all fluences and time scales tested. Most importantly, the bimolecular recombination coefficient is found to be time-dependent, with an initial value of ca. 10{sup −9} cm{sup 3}/s and a progressive reduction within the first tens of nanoseconds. Comparison to the prototypical organic bulk heterojunction device PTB7:PC{sub 71}BM yields important differences with regard to the mechanism and time scale of free carrier recombination.

  10. Justified chauvinism: advances in defining meiotic recombination through sperm typing.

    Science.gov (United States)

    Carrington, Mary; Cullen, Michael

    2004-04-01

    Sperm typing offers an efficient means of studying the quantitative and qualitative aspects of meiotic recombination that are virtually unapproachable by pedigree analysis. Since the initial development of the technique >10 years ago, several salient findings based on empirically derived recombination data have been described. The precise rates and distributions of recombination have been reported for specific regions of the genome, serving as the prototype for high-resolution genome-wide recombination patterns. Identification and characterization of molecular genetic events, such as unequal crossing over, gene conversion and crossover asymmetry, are under close inspection for the first time as a result of this technology. The influence of these phenomena on the evolution of the genome is of primary interest from a scientific and medical perspective. In this article, we review the novel discoveries in mammalian meiotic recombination that have been revealed through sperm typing.

  11. Efficient Inference of Recent and Ancestral Recombination within Bacterial Populations.

    Science.gov (United States)

    Mostowy, Rafal; Croucher, Nicholas J; Andam, Cheryl P; Corander, Jukka; Hanage, William P; Marttinen, Pekka

    2017-05-01

    Prokaryotic evolution is affected by horizontal transfer of genetic material through recombination. Inference of an evolutionary tree of bacteria thus relies on accurate identification of the population genetic structure and recombination-derived mosaicism. Rapidly growing databases represent a challenge for computational methods to detect recombinations in bacterial genomes. We introduce a novel algorithm called fastGEAR which identifies lineages in diverse microbial alignments, and recombinations between them and from external origins. The algorithm detects both recent recombinations (affecting a few isolates) and ancestral recombinations between detected lineages (affecting entire lineages), thus providing insight into recombinations affecting deep branches of the phylogenetic tree. In simulations, fastGEAR had comparable power to detect recent recombinations and outstanding power to detect the ancestral ones, compared with state-of-the-art methods, often with a fraction of computational cost. We demonstrate the utility of the method by analyzing a collection of 616 whole-genomes of a recombinogenic pathogen Streptococcus pneumoniae, for which the method provided a high-resolution view of recombination across the genome. We examined in detail the penicillin-binding genes across the Streptococcus genus, demonstrating previously undetected genetic exchanges between different species at these three loci. Hence, fastGEAR can be readily applied to investigate mosaicism in bacterial genes across multiple species. Finally, fastGEAR correctly identified many known recombination hotspots and pointed to potential new ones. Matlab code and Linux/Windows executables are available at https://users.ics.aalto.fi/~pemartti/fastGEAR/ (last accessed February 6, 2017). © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  12. Photoionization and electron-ion recombination of P II

    Science.gov (United States)

    Nahar, Sultana N.

    2017-08-01

    A study of the inverse processes of photoionization and electron-ion recombination of P II is reported. Phosphorus, a little studied cosmic element, requires atomic parameters such as those presented here for spectral analysis. The unified method of Nahar and Pradhan, which incorporates two methods of recombination - radiative recombination (RR) and dielectronic recombination (DR) - and the interference between them, is used to obtain the total electron-ion recombination. This method implements the framework of the {R}-matrix close-coupling approximation. The present results include the partial photoionization cross-sections σPI(Jπ) leaving the residual ion in the ground level and level-specific recombination rate coefficients, αRC(Jπ), of 475 fine-structure levels of P II with n ≤10. In photoionization of the ground and many excited levels, a sharp resonance is found to form at the ionization threshold from couplings of relativistic fine-structure channels. These, with other resonances in the near-threshold energy region, yield a slight curvature, in contrast to typical smooth decay, at a very low temperature of about 330 K in the total recombination rate coefficient αRC. The presence of other Rydberg and Seaton resonances in the photoionization cross-section introduces features in the level-specific recombination rate coefficients and a DR bump at high temperature at 105 K for the total recombination rate coefficient. Considerable interference between RR and DR is noted around 6700 K. The recombination spectrum with respect to photoelectron energy αRC(E) is also presented. The results are expected to provide accurate models for astrophysical plasmas up to ˜1 MK.

  13. Organization and Evolution of a Gene-Rich Region of the Mouse Genome: A 12.7-Mb Region Deleted in the Del(13)Svea36H Mouse

    Science.gov (United States)

    Mallon, Ann-Marie; Wilming, Laurens; Weekes, Joseph; Gilbert, James G.R.; Ashurst, Jennifer; Peyrefitte, Sandrine; Matthews, Lucy; Cadman, Matthew; McKeone, Richard; Sellick, Chris A.; Arkell, Ruth; Botcherby, Marc R.M.; Strivens, Mark A.; Campbell, R. Duncan; Gregory, Simon; Denny, Paul; Hancock, John M.; Rogers, Jane; Brown, Steve D.M.

    2004-01-01

    Del(13)Svea36H (Del36H) is a deletion of ∼20% of mouse chromosome 13 showing conserved synteny with human chromosome 6p22.1-6p22.3/6p25. The human region is lost in some deletion syndromes and is the site of several disease loci. Heterozygous Del36H mice show numerous phenotypes and may model aspects of human genetic disease. We describe 12.7 Mb of finished, annotated sequence from Del36H. Del36H has a higher gene density than the draft mouse genome, reflecting high local densities of three gene families (vomeronasal receptors, serpins, and prolactins) which are greatly expanded relative to human. Transposable elements are concentrated near these gene families. We therefore suggest that their neighborhoods are gene factories, regions of frequent recombination in which gene duplication is more frequent. The gene families show different proportions of pseudogenes, likely reflecting different strengths of purifying selection and/or gene conversion. They are also associated with relatively low simple sequence concentrations, which vary across the region with a periodicity of ∼5 Mb. Del36H contains numerous evolutionarily conserved regions (ECRs). Many lie in noncoding regions, are detectable in species as distant as Ciona intestinalis, and therefore are candidate regulatory sequences. This analysis will facilitate functional genomic analysis of Del36H and provides insights into mouse genome evolution. PMID:15364904

  14. Recombination in Escherichia coli V. Genetic analysis of recombinants from crosses with recipients deficient in ATP-dependent exonuclease activity

    NARCIS (Netherlands)

    Haan, P.G. de; Hoekstra, W.P.M.; Verhoef, C.

    A genetic analysis of recombinants from crosses with recombination-deficient recipients, lacking the ATP-dependent exonuclease activity, demonstrated differences in the inheritance pattern of donor markers compared with a Rec+ recipient. In particular the donor markers proximal to the transfer

  15. Patterns of Human Immunodeficiency Virus type 1 recombination ex vivo provide evidence for coadaptation of distant sites, resulting in purifying selection for intersubtype recombinants during replication

    DEFF Research Database (Denmark)

    Galli, Andrea; Kearney, Mary; Nikolaitchik, Olga A

    2010-01-01

    in human populations. We hypothesize that sequence diversity affects the emergence of viable recombinants by decreasing recombination events and reducing the ability of the recombinants to replicate. To test our hypothesis, we compared recombination between two viruses containing subtype B pol genes (B....../F than in B/B viruses, and the overall distribution of crossover junctions in pol was similar for the two classes of recombinants. We then examined the emergence of recombinants in a multiple cycle assay, so that functional pol gene products were selected. We found that the emerging B/B recombinants had...

  16. Characteristics of mastication in the anodontic mouse.

    Science.gov (United States)

    Kobayashi, M; Masuda, Y; Kishino, M; Ishida, T; Maeda, N; Morimoto, T

    2002-09-01

    Teeth and periodontal mechanoreceptors play important roles in regulating jaw movements during mastication. However, little is known concerning how jaw movements develop without tooth eruption. To answer this question, we studied masticatory behavior in the osteopetrotic mouse, where tooth eruption does not occur and periodontal mechanoreceptors are missing. A masticatory sequence of the osteopetrotic mouse was divided into two stages: incision and chewing. Incision is characterized by small amplitude and rapid (7 Hz) open-close jaw movements, while slow (5 Hz) and large amplitude open-close jaw movements characterize chewing. The frequency and properties of jaw movements were comparable with those in the normal mouse, though the osteopetrotic mouse had a higher cycle number during incision than did the normal mouse. These results indicate that conversion from sucking to mastication occurs in the anodontic mouse, and the central pattern generator producing the masticatory rhythm develops almost normally without tooth eruption.

  17. Effects of the rad52 gene on recombination in Saccharomyces cerevisiae. [Comparison of. gamma. -, uv-induced meiotic and spontaneous mitotic recombination

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, S.; Prakash, L.; Burke, W.; Montelone, B.A.

    1979-01-01

    Effects of the rad52 mutation in Saccharomyces cerevisiae on meiotic, ..gamma..-ray-induced, uv-induced, and spontaneous mitotic recombination were studied. The rad52/rad52 diploids undergo premeiotic DNA synthesis; sporulation occurs but inviable spores are produced. Intra- and intergenic recombination during meiosis were examined in cells transferred from sporulation medium to vegetative medium at different time intervals. No intragenic recombination was observed at the hisl-1/hisl-315 and trp5-2/trp5-48 heteroalleles. Gene-centromere recombination was also not observed in rad52/rad52 diploids. No ..gamma..-ray-induced intragenic mitotic recombination is seen in rad52/rad52 diploids and uv-induced intragenic recombination is greatly reduced. However, spontaneous mitotic recombination is not similarly affected. The RAD52 gene thus functions in recombination in meiosis and in ..gamma..-ray and uv-induced mitotic recombination but not in spontaneous mitotic recombination.

  18. The interaction of beta 2-microglobulin (beta 2m) with mouse class I major histocompatibility antigens and its ability to support peptide binding. A comparison of human and mouse beta 2m

    DEFF Research Database (Denmark)

    Pedersen, L O; Stryhn, A; Holter, T L

    1995-01-01

    of class I molecules are involved in peptide binding, whereas most of class I molecules are involved in beta 2m binding. We propose that mouse beta 2m interacts with the minor peptide binding (i.e. the "empty") fraction with a lower affinity than human beta 2m does, whereas mouse and human beta 2m interact......The function of major histocompatibility complex (MHC) class I molecules is to sample peptides derived from intracellular proteins and to present these peptides to CD8+ cytotoxic T lymphocytes. In this paper, biochemical assays addressing MHC class I binding of both peptide and beta 2-microglobulin...... (beta 2m) have been used to examine the assembly of the trimolecular MHC class I/beta 2m/peptide complex. Recombinant human beta 2m and mouse beta 2ma have been generated to compare the binding of the two beta 2m to mouse class I. It is frequently assumed that human beta 2m binds to mouse class I heavy...

  19. Activation of peritoneal cells upon in vivo transfection with a recombinant alphavirus expressing GM-CSF

    NARCIS (Netherlands)

    Klimp, AH; Lansink, PO; Withoff, S; de Vries, EGE; Scherphof, GL; Wilschut, J; Daemen, T

    In this study we determined the in vivo localization of recombinant proteins expressed by intraperitoneally (i.p.) injected recombinant Semliki Forest virus (SFV) particles. Subsequently, we investigated the influence of i.p. administered SFV particles encoding recombinant murine

  20. Bio-equivalent doses of recombinent HCG and recombinent LH during ovarian stimulation result in similar oestradiol output

    DEFF Research Database (Denmark)

    Alsbjerg, Birgit; Elbaek, Helle Olesen; Laursen, Rita Jakubcionyte

    2017-01-01

    In nature, HCG is secreted by the implanting embryo from peri-implantation and onwards. In contrast, LH is mandatory for steroidogenesis and follicular development during the follicular phase, working in synergy with FSH. Moreover, LH is mandatory for the function of the corpus luteum. Although LH...... and HCG bind to the same receptor, significant molecular, structural and functional differences exist, inducing differences in bioactivity. This randomized controlled study compared the effect of recombinant FSH stimulation combined with daily either micro-dose recombinant HCG or recombinant LH...... oestradiol level in the HCG supplemented group was 8662 pmol/l versus 9203 pmol/l in the recombinant LH supplemented group; therefore, no significant difference was found. Moreover, no differences were observed in the number of oocytes retrieved or in the live birth rate. We conclude that recombinant HCG...

  1. Evidence of recombination within human alpha-papillomavirus

    Directory of Open Access Journals (Sweden)

    Carvajal-Rodríguez Antonio

    2007-03-01

    Full Text Available Abstract Background Human papillomavirus (HPV has a causal role in cervical cancer with almost half a million new cases occurring each year. Presence of the carcinogenic HPV is necessary for the development of the invasive carcinoma of the genital tract. Therefore, persistent infection with carcinogenic HPV causes virtually all cervical cancers. Some aspects of the molecular evolution of this virus, as the putative importance of recombination in its evolutionary history, are an opened current question. In addition, recombination could also be a significant issue nowadays since the frequency of co-infection with more than one HPV type is not a rare event and, thus, new recombinant types could be currently being generated. Results We have used human alpha-PV sequences from the public database at Los Alamos National Laboratory to report evidence that recombination may exist in this virus. A model-based population genetic approach was used to infer the recombination signal from the HPV DNA sequences grouped attending to phylogenetic and epidemiological information, as well as to clinical manifestations. Our results agree with recently published ones that use a different methodology to detect recombination associated to the gene L2. In addition, we have detected significant recombination signal in the genes E6, E7, L2 and L1 at different groups, and importantly within the high-risk type HPV16. The method used has recently been shown to be one of the most powerful and reliable procedures to detect the recombination signal. Conclusion We provide new support to the recent evidence of recombination in HPV. Additionally, we performed the recombination estimation assuming the best-fit model of nucleotide substitution and rate variation among sites, of the HPV DNA sequence sets. We found that the gene with recombination in most of the groups is L2 but the highest values were detected in L1 and E6. Gene E7 was recombinant only within the HPV16 type. The

  2. The International Mouse Phenotyping Consortium: past and future perspectives on mouse phenotyping

    OpenAIRE

    Brown, Steve D. M.; Moore, Mark W.

    2012-01-01

    Determining the function of all mammalian genes remains a major challenge for the biomedical science community in the 21st century. The goal of the International Mouse Phenotyping Consortium (IMPC) over the next 10 years is to undertake broad-based phenotyping of 20,000 mouse genes, providing an unprecedented insight into mammalian gene function. This short article explores the drivers for large-scale mouse phenotyping and provides an overview of the aims and processes involved in IMPC mouse ...

  3. Functional expression of mouse insulin-like growth factor-I with food-grade vector in Lactococcus lactis NZ9000.

    Science.gov (United States)

    Gao, G; Qiao, J-J; Yang, C-H; Jiang, D-Z; Li, R-Q; Su, J-J; Xu, H-J; Zhang, X-M; Bai, Y-L; Qiao, M-Q

    2012-05-01

      To functionally express the recombinant mouse insulin-like growth factor-I (rtmIGF-I) in Lactococcus lactis NZ9000 with a food-grade vector.   The rtmIGF-I encoding sequence was inserted into secreted food-grade vector pLEB688 and transformed into L. lactis NZ9000. The expression of the recombinant protein rtmIGF-I was confirmed by tricine-SDS-PAGE analysis and Western blot. The concentration of this recombinant protein was 3 mg l(-1) in the medium fraction. Further experiment demonstrated that the recombinant protein was biologically active and promoted NIH3T3 cell proliferation in a concentration-dependent manner.   The rtmIGF-I was expressed in L. lactis and located into the medium fraction. The optimal final concentration which could promote NIH3T3 cell proliferation after incubation was 100 ng ml(-1) .   The rtmIGF-I was functionally expressed in L. lactis NZ9000 with a food-grade vector. Thus, the recombinant L. lactis NZ9000 could act as a host for the production of rtmIGF-I for further study. The recombinant strain could serve as an IGF-I delivery system. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  4. Characterization of Recombinant B. abortus Strain RB51SOD Toward Understanding the Uncorrelated Innate and Adaptive Immune Responses Induced by RB51SOD Compared to Its Parent Vaccine Strain RB51

    OpenAIRE

    Zhu, Jianguo; Larson, Charles B.; Ramaker, Megan Ann; Quandt, Kimberly; Wendte, Jered M.; Ku, Kimberly P.; Chen, Fang; Jourdian, George W.; Vemulapalli, Ramesh; Schurig, Gerhardt G.; He, Yongqun

    2011-01-01

    Brucella abortus is a Gram-negative, facultative intracellular pathogen for several mammals, including humans. Live attenuated B. abortus strain RB51 is currently the official vaccine used against bovine brucellosis in the United States and several other countries. Overexpression of protective B. abortus antigen Cu/Zn superoxide dismutase (SOD) in a recombinant strain of RB51 (strain RB51SOD) significantly increases its vaccine efficacy against virulent B. abortus challenge in a mouse model. ...

  5. Characterization of recombinant B. abortus strain RB51SOD towards understanding the uncorrelated innate and adaptive immune responses induced by RB51SOD compared to its parent vaccine strain RB51

    OpenAIRE

    Jianguo eZhu; Jianguo eZhu; Charles Bradford Larson; Megan Ann Ramaker; Kimberly eQuandt; Jered eWendte; Kimberly eKu; Fang eChen; George eJourdian; Ramesh eVemulapalli; Gerhardt G. Schurig; Yongqun Oliver eHe

    2011-01-01

    Brucella abortus is a Gram-negative, facultative intracellular pathogen for several mammals, including humans. Live attenuated B. abortus strain RB51 is currently the official vaccine used against bovine brucellosis in the United States and several other countries. Overexpression of protective B. abortus antigen Cu/Zn superoxide dismutase (SOD) in a recombinant strain of RB51 (strain RB51SOD) significantly increases its vaccine efficacy against virulent B. abortus challenge in a mouse model. ...

  6. Therapeutic cloning in the mouse

    Science.gov (United States)

    Mombaerts, Peter

    2003-01-01

    Nuclear transfer technology can be applied to produce autologous differentiated cells for therapeutic purposes, a concept termed therapeutic cloning. Countless articles have been published on the ethics and politics of human therapeutic cloning, reflecting the high expectations from this new opportunity for rejuvenation of the aging or diseased body. Yet the research literature on therapeutic cloning, strictly speaking, is comprised of only four articles, all in the mouse. The efficiency of derivation of embryonic stem cell lines via nuclear transfer is remarkably consistent among these reports. However, the efficiency is so low that, in its present form, the concept is unlikely to become widespread in clinical practice. PMID:12949262

  7. Phylogenetic and recombination analysis of tomato spotted wilt virus.

    Directory of Open Access Journals (Sweden)

    Sen Lian

    Full Text Available Tomato spotted wilt virus (TSWV severely damages and reduces the yield of many economically important plants worldwide. In this study, we determined the whole-genome sequences of 10 TSWV isolates recently identified from various regions and hosts in Korea. Phylogenetic analysis of these 10 isolates as well as the three previously sequenced isolates indicated that the 13 Korean TSWV isolates could be divided into two groups reflecting either two different origins or divergences of Korean TSWV isolates. In addition, the complete nucleotide sequences for the 13 Korean TSWV isolates along with previously sequenced TSWV RNA segments from Korea and other countries were subjected to phylogenetic and recombination analysis. The phylogenetic analysis indicated that both the RNA L and RNA M segments of most Korean isolates might have originated in Western Europe and North America but that the RNA S segments for all Korean isolates might have originated in China and Japan. Recombination analysis identified a total of 12 recombination events among all isolates and segments and five recombination events among the 13 Korea isolates; among the five recombinants from Korea, three contained the whole RNA L segment, suggesting reassortment rather than recombination. Our analyses provide evidence that both recombination and reassortment have contributed to the molecular diversity of TSWV.

  8. Data Mining for Expressivity of Recombinant Protein Expression

    Science.gov (United States)

    Kira, Satoshi; Isoai, Atsushi; Yamamura, Masayuki

    We analyzed the expressivity of recombinant proteins by using data mining methods. The expression technique of recombinant protein is a key step towards elucidating the functions of genes discovered through genomic sequence projects. We have studied the productive efficiency of recombinant proteins in fission yeast, Schizosaccharomyces pombe (S.pombe), by mining the expression results. We gathered 57 proteins whose expression levels were known roughly in the host. Correlation analysis, principal component analysis and decision tree analysis were applied to these expression data. Analysis featuring codon usage and amino acid composition clarified that the amino acid composition affected to the expression levels of a recombinant protein strongly than the effect of codon usage. Furthermore, analysis of amino acid composition showed that protein solubility and the metabolism cost of amino acids correlated with a protein expressivity. Codon usage was often interesting in the field of recombinant expressions. However, our analysis found the weak correlation codon features with expressivities. These results indicated that ready-made indices of codon bias were irrelevant ones for modeling the expressivities of recombinant proteins. Our data driven approach was an easy and powerful method to improve recombinant protein expression, and this approach should be concentrated attention with the huge amount of expression data accumulating through the post-genome era.

  9. [Construction of mouse VCAM-1 expression vector and establishment of stably transfected MSC line C3H10T1/2].

    Science.gov (United States)

    Chen, Hui; Zhu, Heng; Chu, Ya-Nan; Xu, Fen-Fen; Liu, Yuan-Lin; Tang, Bo; Li, Xi-Mei; Hu, Liang-Ding; Zhang, Yi

    2014-10-01

    This study was aimed to construct the mouse VCAM-1 expression vector, to establish the stably transfected MSC line and to investigate the effect of VCAM-1-modified mesenchymal stem cells (MSC) on the immunological characteristics of MSC. The cDNA of murine VCAM-1 gene was amplified by RT-PCR from the total RNA isolated from the mouse spleen; then the cDNA was inserted into the retrovirus vector PMSCVmigr-1; the recombinant plasmid was confirmed by restriction endonuclease experiments and sequencing, then designated as PMSCVmigr-1-mVCAM-1; the recombinant plasmid PMSCVmigr-1-mVCAM-1 was transfected into 293 cells by lipofecamin and the supernatant was collected to transfect MSC cell line (C3H10T1/2). Moreover, VCAM-1 expression on MSC was evaluated by FACS. Furthermore, the inhibitory effect of VCAM-1-MSC on lymphocytic transformation was tested by (3)H-TdR incorporation assay. The results indicated that the successful construction of recombinant retroviral expression plasmid of mouse VCAM-1 was confirmed by digesting and sequancing. After transfection of MSC with retroviral supernaptant, the high expression of VCAM-1 on MSC could be detected by flow cytometry. The MSC high expressing VCAM-1 could significantly inhibit the proliferation of Con A-inducing lymphocytes in dose-depentent marrer. It is concluded that recombinant retroviral encoding VCAM-1 (PMSCVmigr-1-mVCAM-1) has been successfully constructed and mouse VCAM-1 has been stably expressed in C3H10T1/2. MSC over-expressing VCAM-1 show more potent immunosuppressive effect on cellular immune reaction in vitro. Our data laid a foundation for the subsequent studying the effect of VCAM-1 transfecting into MSC on immune related disease study.

  10. Constitutive expression of ciliary neurotrophic factor in mouse hypothalamus.

    Science.gov (United States)

    Severi, Ilenia; Carradori, Maria Rita; Lorenzi, Teresa; Amici, Adolfo; Cinti, Saverio; Giordano, Antonio

    2012-06-01

    Ciliary neurotrophic factor (CNTF) is a potent survival molecule for a large number of neuronal and glial cells in culture; its expression in glial cells is strongly upregulated after a variety of nerve tissue injuries. Exogenously administered CNTF produces an anorectic effect via activation of hypothalamic neurons and stimulates neurogenesis in mouse hypothalamus. To determine whether CNTF is produced endogenously in the hypothalamus, we sought cellular sources and examined their distribution in adult mouse hypothalamus by immunohistochemistry. CNTF immunoreactivity (IR) was predominantly detected in the ependymal layer throughout the rostrocaudal extension of the third ventricle, where numerous ependymocytes and tanycytes exhibited specific staining. Some astrocytes in the grey matter of the anterior hypothalamus and in the median eminence of the hypothalamic tuberal region were also positive. Stimulation of cells bearing CNTF receptor α (CNTFRα) induces specific activation of the signal transducer and activator of transcription 3 (STAT3) signalling system. Treatment with recombinant CNTF and detection of the nuclear expression of phospho-STAT3 (P-STAT3) showed that CNTF-producing ependymal cells and tanycytes were intermingled with, or very close to, P-STAT3-positive, CNTFRα-bearing cells. A fraction of CNTF-producing ependymal cells and tanycytes and some median eminence astrocytes also exhibited P-STAT3 IR. Thus, in normal adult mice the ependyma of the third ventricle is both a source of and a target for CNTF, which may play hitherto unknown roles in hypothalamic function in physiological conditions. © 2012 The Authors. Journal of Anatomy © 2012 Anatomical Society.

  11. Recombinant viruses as vaccines against viral diseases

    Directory of Open Access Journals (Sweden)

    A.P.D. Souza

    2005-04-01

    Full Text Available Vaccine approaches to infectious diseases are widely applied and appreciated. Amongst them, vectors based on recombinant viruses have shown great promise and play an important role in the development of new vaccines. Many viruses have been investigated for their ability to express proteins from foreign pathogens and induce specific immunological responses against these antigens in vivo. Generally, gene-based vaccines can stimulate potent humoral and cellular immune responses and viral vectors might be an effective strategy for both the delivery of antigen-encoding genes and the facilitation and enhancement of antigen presentation. In order to be utilized as a vaccine carrier, the ideal viral vector should be safe and enable efficient presentation of required pathogen-specific antigens to the immune system. It should also exhibit low intrinsic immunogenicity to allow for its re-administration in order to boost relevant specific immune responses. Furthermore, the vector system must meet criteria that enable its production on a large-scale basis. Several viral vaccine vectors have thus emerged to date, all of them having relative advantages and limits depending on the proposed application, and thus far none of them have proven to be ideal vaccine carriers. In this review we describe the potential, as well as some of the foreseeable obstacles associated with viral vaccine vectors and their use in preventive medicine.

  12. Recombination-assisted megaprimer (RAM) cloning

    Science.gov (United States)

    Mathieu, Jacques; Alvarez, Emilia; Alvarez, Pedro J.J.

    2014-01-01

    No molecular cloning technique is considered universally reliable, and many suffer from being too laborious, complex, or expensive. Restriction-free cloning is among the simplest, most rapid, and cost-effective methods, but does not always provide successful results. We modified this method to enhance its success rate through the use of exponential amplification coupled with homologous end-joining. This new method, recombination-assisted megaprimer (RAM) cloning, significantly extends the application of restriction-free cloning, and allows efficient vector construction with much less time and effort when restriction-free cloning fails to provide satisfactory results. The following modifications were made to the protocol:•Limited number of PCR cycles for both megaprimer synthesis and the cloning reaction to reduce error propagation.•Elimination of phosphorylation and ligation steps previously reported for cloning methods that used exponential amplification, through the inclusion of a reverse primer in the cloning reaction with a 20 base pair region of homology to the forward primer.•The inclusion of 1 M betaine to enhance both reaction specificity and yield. PMID:26150930

  13. Recombinant phage probes for Listeria monocytogenes

    Science.gov (United States)

    Carnazza, S.; Gioffrè, G.; Felici, F.; Guglielmino, S.

    2007-10-01

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 104 cells ml-1. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  14. Meiotic Recombination in the Giraffe (G. reticulata).

    Science.gov (United States)

    Vozdova, Miluse; Fröhlich, Jan; Kubickova, Svatava; Sebestova, Hana; Rubes, Jiri

    2017-01-01

    Recently, the reticulated giraffe (G. reticulata) was identified as a distinct species, which emphasized the need for intensive research in this interesting animal. To shed light on the meiotic process as a source of biodiversity, we analysed the frequency and distribution of meiotic recombination in 2 reticulated giraffe males. We used immunofluorescence detection of synaptonemal complex protein (SYCP3), meiotic double strand breaks (DSB, marked as RAD51 foci) in leptonema, and crossovers (COs, as MLH1 foci) in pachynema. The mean number of autosomal MLH1 foci per cell (27), which resulted from a single, distally located MLH1 focus observed on most chromosome arms, is one of the lowest among mammalian species analysed so far. The CO/DSB conversion ratio was 0.32. The pseudoautosomal region was localised in the Xq and Yp termini by FISH and showed an MLH1 focus in 83% of the pachytene cells. Chromatin structures corresponding to the nucleolus organiser regions were observed in the pachytene spermatocytes. The results are discussed in the context of known data on meiosis in Cetartiodactyla, depicting that the variation in CO frequency among species of this taxonomic group is mostly associated with their diploid chromosome number. © 2017 S. Karger AG, Basel.

  15. Epigenetic codes programming class switch recombination

    Directory of Open Access Journals (Sweden)

    Bharat eVaidyanathan

    2015-09-01

    Full Text Available Class switch recombination imparts B cells with a fitness-associated adaptive advantage during a humoral immune response by using a precision-tailored DNA excision and ligation process to swap the default constant region gene of the antibody with a new one that has unique effector functions. This secondary diversification of the antibody repertoire is a hallmark of the adaptability of B cells when confronted with environmental and pathogenic challenges. Given that the nucleotide sequence of genes during class switching remains unchanged (genetic constraints, it is logical and necessary therefore, to integrate the adaptability of B cells to an epigenetic state, which is dynamic and can be heritably modulated before, after or even during an antibody-dependent immune response. Epigenetic regulation encompasses heritable changes that affect function (phenotype without altering the sequence information embedded in a gene, and include histone, DNA and RNA modifications. Here, we review current literature on how B cells use an epigenetic code language as a means to ensure antibody plasticity in light of pathogenic insults.

  16. Therapeutic Use of Native and Recombinant Enteroviruses.

    Science.gov (United States)

    Ylä-Pelto, Jani; Tripathi, Lav; Susi, Petri

    2016-02-23

    Research on human enteroviruses has resulted in the identification of more than 100 enterovirus types, which use more than 10 protein receptors and/or attachment factors required in cell binding and initiation of the replication cycle. Many of these "viral" receptors are overexpressed in cancer cells. Receptor binding and the ability to replicate in specific target cells define the tropism and pathogenesis of enterovirus types, because cellular infection often results in cytolytic response, i.e., disruption of the cells. Viral tropism and cytolytic properties thus make native enteroviruses prime candidates for oncolytic virotherapy. Copy DNA cloning and modification of enterovirus genomes have resulted in the generation of enterovirus vectors with properties that are useful in therapy or in vaccine trials where foreign antigenic epitopes are expressed from or on the surface of the vector virus. The small genome size and compact particle structure, however, set limits to enterovirus genome modifications. This review focuses on the therapeutic use of native and recombinant enteroviruses and the methods that have been applied to modify enterovirus genomes for therapy.

  17. Therapeutic Use of Native and Recombinant Enteroviruses

    Directory of Open Access Journals (Sweden)

    Jani Ylä-Pelto

    2016-02-01

    Full Text Available Research on human enteroviruses has resulted in the identification of more than 100 enterovirus types, which use more than 10 protein receptors and/or attachment factors required in cell binding and initiation of the replication cycle. Many of these “viral” receptors are overexpressed in cancer cells. Receptor binding and the ability to replicate in specific target cells define the tropism and pathogenesis of enterovirus types, because cellular infection often results in cytolytic response, i.e., disruption of the cells. Viral tropism and cytolytic properties thus make native enteroviruses prime candidates for oncolytic virotherapy. Copy DNA cloning and modification of enterovirus genomes have resulted in the generation of enterovirus vectors with properties that are useful in therapy or in vaccine trials where foreign antigenic epitopes are expressed from or on the surface of the vector virus. The small genome size and compact particle structure, however, set limits to enterovirus genome modifications. This review focuses on the therapeutic use of native and recombinant enteroviruses and the methods that have been applied to modify enterovirus genomes for therapy.

  18. Recombinant canine coronaviruses in dogs, Europe.

    Science.gov (United States)

    Decaro, Nicola; Mari, Viviana; Elia, Gabriella; Addie, Diane D; Camero, Michele; Lucente, Maria Stella; Martella, Vito; Buonavoglia, Canio

    2010-01-01

    Coronaviruses of potential recombinant origin with porcine transmissible gastroenteritis virus (TGEV), referred to as a new subtype (IIb) of canine coronavirus (CCoV), were recently identified in dogs in Europe. To assess the distribution of the TGEV-like CCoV subtype, during 2001-2008 we tested fecal samples from dogs with gastroenteritis. Of 1,172 samples, 493 (42.06%) were positive for CCoV. CCoV-II was found in 218 samples, and CCoV-I and CCoV-II genotypes were found in 182. Approximately 20% of the samples with CCoV-II had the TGEV-like subtype; detection rates varied according to geographic origin. The highest and lowest rates of prevalence for CCoV-II infection were found in samples from Hungary and Greece (96.87% and 3.45%, respectively). Sequence and phylogenetic analyses showed that the CCoV-IIb strains were related to prototype TGEV-like strains in the 5' and the 3' ends of the spike protein gene.

  19. Recombinant phage probes for Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S; Gioffre, G; Felici, F; Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2007-10-03

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 10{sup 4} cells ml{sup -1}. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  20. Recombinative generalization of subword units using matching to sample.

    LENUS (Irish Health Repository)

    Mahon, Catherine

    2010-01-01

    The purpose of the current study was to develop and test a computerized matching-to-sample (MTS) protocol to facilitate recombinative generalization of subword units (onsets and rimes) and recognition of novel onset-rime and onset-rime-rime words. In addition, we sought to isolate the key training components necessary for recombinative generalization. Twenty-five literate adults participated. Conditional discrimination training emerged as a crucial training component. These findings support the effectiveness of MTS in facilitating recombinative generalization, particularly when conditional discrimination training with subword units is used.

  1. Recombination among multiple mitochondrial pseudogenes from a passerine genus

    DEFF Research Database (Denmark)

    Nielsen, Kirstine Klitgaard; Arctander, P.

    2001-01-01

    pseudogenes consisted of multiple haplotypes found to diverge from 1 to 16% from the mitochondrial gene. The number of mitochondrial nuclear copies and their apparent frequent recombination suggest that pseudogenes constitute a serious potential risk in confounding phylogenetic studies and population genetic...... to the observed differences in substitution patterns 58% of the cloned sequences were identified as pseudogenes. Recombination could be traced in 19% of the inferred nuclear pseudogenes, but this figure probably represents a Significant underestimation of the factual recombination events. The nonrecombined...

  2. General features of the dissociative recombination of polyatomic molecules

    Directory of Open Access Journals (Sweden)

    Pratt S.T.

    2015-01-01

    Full Text Available We discuss some aspects of a simple expression for the low-energy dissociative recombination cross section that applies when the recombination process is dominated by the indirect mechanism. In most previous applications, this expression has been applied to capture into vibrationally excited Rydberg states with the assumption that capture is always followed by prompt dissociation. Here we consider the dissociative recombination of larger polyatomic ions and electrons. More specifically, we consider capture into electronically core-excited Rydberg states, and begin to assess its potential importance for larger systems.

  3. Enhancers located in heavy chain regulatory region (hs3a, hs1,2, hs3b, and hs4) are dispensable for diversity of VDJ recombination.

    Science.gov (United States)

    Rouaud, Pauline; Vincent-Fabert, Christelle; Fiancette, Remi; Cogné, Michel; Pinaud, Eric; Denizot, Yves

    2012-03-09

    V(D)J recombination occurs during the antigen-independent early steps of B-cell ontogeny. Multiple IgH cis-regulatory elements control B-cell ontogeny. IGCR1 (intergenic control region 1), the DQ52 promoter/enhancer, and the intronic Emu enhancer, all three located upstream of Cmu, have important roles during V(D)J recombination, whereas there is no clue about a role of the IgH regulatory region (RR) encompassing the four transcriptional enhancers hs3a, hs1,2, hs3b, and hs4 during these early stages. To clarify the role of the RR in V(D)J recombination, we totally deleted it in the mouse genome. Here, we show that V(D)J recombination is unaffected by the complete absence of the IgH RR, highlighting that this region only orchestrates IgH locus activity during the late stages of B-cell differentiation. In contrast, the earliest antigen-independent steps of B-cell ontogeny would be under the control of only the upstream Cmu elements of the locus.

  4. Enhancers Located in Heavy Chain Regulatory Region (hs3a, hs1,2, hs3b, and hs4) Are Dispensable for Diversity of VDJ Recombination*

    Science.gov (United States)

    Rouaud, Pauline; Vincent-Fabert, Christelle; Fiancette, Remi; Cogné, Michel; Pinaud, Eric; Denizot, Yves

    2012-01-01

    V(D)J recombination occurs during the antigen-independent early steps of B-cell ontogeny. Multiple IgH cis-regulatory elements control B-cell ontogeny. IGCR1 (intergenic control region 1), the DQ52 promoter/enhancer, and the intronic Emu enhancer, all three located upstream of Cmu, have important roles during V(D)J recombination, whereas there is no clue about a role of the IgH regulatory region (RR) encompassing the four transcriptional enhancers hs3a, hs1,2, hs3b, and hs4 during these early stages. To clarify the role of the RR in V(D)J recombination, we totally deleted it in the mouse genome. Here, we show that V(D)J recombination is unaffected by the complete absence of the IgH RR, highlighting that this region only orchestrates IgH locus activity during the late stages of B-cell differentiation. In contrast, the earliest antigen-independent steps of B-cell ontogeny would be under the control of only the upstream Cmu elements of the locus. PMID:22270371

  5. Interallelic class switch recombination can reverse allelic exclusion and allow trans-complementation of an IgH locus switching defect.

    Science.gov (United States)

    Dougier, Hei-Lanne; Reynaud, Stéphane; Pinaud, Eric; Carrion, Claire; Delpy, Laurent; Cogné, Michel

    2006-08-01

    The predominant path of immunoglobulin class switch recombination follows the paradigm of intra-chromosomal deletion enabling expression of another heavy chain instead of micro and delta. This was, however, challenged by observations of inter-allelic class switch recombination in rabbit or mouse IgG3- or IgA-producing B cells. Assuming that the conditions of inter-chromosomal exchange are likely present at any target S regions in stimulated B cells, we explored trans-association of VH and C genes in a model allowing all C genes to be checked simultaneously. Heterozygous mutant mice are thus studied, which carry one non-functional IgH allele inactivated by a non-translatable mutation of VDJ-CH transcripts, while the functional allele is deficient for class switching due to a truncated 3'regulatory region. A fair level of switching to all Ig classes is restored in heterozygous mice despite the fact that cis-recombination is either non productive on one allele or deficient on the other. Molecular evidence at the DNA level of trans-CSR to IgG3 was demonstrated by cloning and sequencing Smu-Sgamma3 hybrid junctions. These data demonstrate that inter-allelic recombination may broadly rescue the production of various class-switched isotypes and allow complementation between mutations located at both ends of the IgH constant gene cluster.

  6. PAX6 MiniPromoters drive restricted expression from rAAV in the adult mouse retina

    Directory of Open Access Journals (Sweden)

    Jack W Hickmott

    2016-01-01

    Full Text Available Current gene therapies predominantly use small, strong, and readily available ubiquitous promoters. However, as the field matures, the availability of small, cell-specific promoters would be greatly beneficial. Here we design seven small promoters from the human paired box 6 (PAX6 gene and test them in the adult mouse retina using recombinant adeno-associated virus. We chose the retina due to previous successes in gene therapy for blindness, and the PAX6 gene since it is: well studied; known to be driven by discrete regulatory regions; expressed in therapeutically interesting retinal cell types; and mutated in the vision-loss disorder aniridia, which is in need of improved therapy. At the PAX6 locus, 31 regulatory regions were bioinformatically predicted, and nine regulatory regions were constructed into seven MiniPromoters. Driving Emerald GFP, these MiniPromoters were packaged into recombinant adeno-associated virus, and injected intravitreally into postnatal day 14 mice. Four MiniPromoters drove consistent retinal expression in the adult mouse, driving expression in combinations of cell-types that endogenously express Pax6: ganglion, amacrine, horizontal, and Müller glia. Two PAX6-MiniPromoters drive expression in three of the four cell types that express PAX6 in the adult mouse retina. Combined, they capture all four cell types, making them potential tools for research, and PAX6-gene therapy for aniridia.

  7. A cross-species genetic analysis identifies candidate genes for mouse anxiety and human bipolar disorder

    Directory of Open Access Journals (Sweden)

    David G Ashbrook

    2015-07-01

    Full Text Available Bipolar disorder (BD is a significant neuropsychiatric disorder with a lifetime prevalence of ~1%. To identify genetic variants underlying BD genome-wide association studies (GWAS have been carried out. While many variants of small effect associated with BD have been identified few have yet been confirmed, partly because of the low power of GWAS due to multiple comparisons being made. Complementary mapping studies using murine models have identified genetic variants for behavioral traits linked to BD, often with high power, but these identified regions often contain too many genes for clear identification of candidate genes. In the current study we have aligned human BD GWAS results and mouse linkage studies to help define and evaluate candidate genes linked to BD, seeking to use the power of the mouse mapping with the precision of GWAS. We use quantitative trait mapping for open field test and elevated zero maze data in the largest mammalian model system, the BXD recombinant inbred mouse population, to identify genomic regions associated with these BD-like phenotypes. We then investigate these regions in whole genome data from the Psychiatric Genomics Consortium’s bipolar disorder GWAS to identify candidate genes associated with BD. Finally we establish the biological relevance and pathways of these genes in a comprehensive systems genetics analysis.We identify four genes associated with both mouse anxiety and human BD. While TNR is a novel candidate for BD, we can confirm previously suggested associations with CMYA5, MCTP1 and RXRG. A cross-species, systems genetics analysis shows that MCTP1, RXRG and TNR coexpress with genes linked to psychiatric disorders and identify the striatum as a potential site of action. CMYA5, MCTP1, RXRG and TNR are associated with mouse anxiety and human BD. We hypothesize that MCTP1, RXRG and TNR influence intercellular signaling in the striatum.

  8. Transfected HEK293 Cells Expressing Functional Recombinant Intercellular Adhesion Molecule 1 (ICAM-1) - A Receptor Associated with Severe Plasmodium falciparum Malaria

    DEFF Research Database (Denmark)

    Bengtsson, Anja; Joergensen, Louise; Barbati, Zachary R

    2013-01-01

    . Additionally, ICAM-1 acts as receptor for pathogens like human rhinovirus and Plasmodium falciparum malaria parasites. A group of related P. falciparum erythrocyte membrane protein 1 (PfEMP1) domains, the DBLβ, mediates ICAM-1 binding of P. falciparum-infected erythrocytes. This ICAM‑1-binding phenotype has...... been suggested to be involved in the development of cerebral malaria. However, more studies identifying cross-reactive antibody and ICAM-1-binding epitopes and the establishment of a clinical link between DBLβ expression and e.g. cerebral malaria are needed before the DBLβ domains can be put forward...... as vaccine candidates and go into clinical trials. Such studies require availability of functional recombinant ICAM-1 in large quantities. In this study, we compared recombinant ICAM-1 expressed in HEK293 and COS-7 cells with mouse myeloma NS0 ICAM-1 purchased from a commercial vendor in terms of protein...

  9. Mouse Models of Tumor Immunotherapy.

    Science.gov (United States)

    Ngiow, Shin Foong; Loi, Sherene; Thomas, David; Smyth, Mark J

    2016-01-01

    Immunotherapy is now evolving into a major therapeutic option for cancer patients. Such clinical advances also promote massive interest in the search for novel immunotherapy targets, and to understand the mechanism of action of current drugs. It is projected that a series of novel immunotherapy agents will be developed and assessed for their therapeutic activity. In light of this, in vivo experimental mouse models that recapitulate human malignancies serve as valuable tools to validate the efficacy and safety profile of immunotherapy agents, before their transition into clinical trials. In this review, we will discuss the major classes of experimental mouse models of cancer commonly used for immunotherapy assessment and provide examples to guide the selection of appropriate models. We present some new data concerning the utility of a carcinogen-induced tumor model for comparing immunotherapies and combining immunotherapy with chemotherapy. We will also highlight some recent advances in experimental modeling of human malignancies in mice that are leading towards personalized therapy in patients. © 2016 Elsevier Inc. All rights reserved.

  10. Take care of your mouse!

    CERN Multimedia

    IT Department

    2011-01-01

    “Stop --- Think --- Click" is the basic recommendation for securely browsing the Internet and for securely reading e-mails. Users who have followed this recommendation in the past were less likely to have their computer infected or their computing account compromised. We would like to thank all those who donated their mouse to the CERN Animal Shelter for Computer Mice (http://cern.ch/c-a-s). For those who still use a mouse, please stay vigilant and  alert: do not click on links whose origin you do not trust or which look like gibberish. Do not install untrusted software or plug-ins, since software from untrusted sources may infect or compromise your computer, or violate copyrights. Finally, take particular care with e-mails: Do not open unexpected or suspicious e-mails or attachments. Delete them if they do not concern you or if they appear strange. If in doubt, or if you have questions, please do not hesitate to contact Computer.Security@cern.ch

  11. Complex History and Differentiation Patterns of the t-Haplotype, a Mouse Meiotic Driver.

    Science.gov (United States)

    Kelemen, Reka K; Vicoso, Beatriz

    2017-11-14

    The t-haplotype, a mouse meiotic driver found on chromosome 17, has been a model for autosomal segregation distortion for close to a century, but several questions remain regarding its biology and evolutionary history. A recently published set of population genomics resources for wild mice includes several individuals heterozygous for the t-haplotype, which we use to characterize this selfish element at the genomic and transcriptomic level. Our results show that large sections of the t-haplotype have been replaced by standard homologous sequences, possibly due to occasional events of recombination, and that this complicates the inference of its history. As expected for a long genomic segment of very low recombination, the t-haplotype carries an excess of fixed nonsynonymous mutations compared to the standard chromosome. This excess is stronger for regions that have not undergone recent recombination, suggesting that occasional gene flow between the t and the standard chromosome may provide a mechanism to regenerate coding sequences that have accumulated deleterious mutations. Finally, we find that t-complex genes with altered expression largely overlap with deleted or amplified regions, and that carrying a t-haplotype alters the testis expression of genes outside of the t-complex, providing new leads into the pathways involved in the biology of this segregation distorter. Copyright © 2017, Genetics.

  12. Generation of an Rx-tTA: TetOp-Cre knock-in mouse line for doxycycline regulated Cre activity in the Rx expression domain.

    Directory of Open Access Journals (Sweden)

    Timothy F Plageman

    Full Text Available Genetic deletion of mouse genes has played a crucial role in our understanding of embryonic eye development. Transgenic, tissue specific Cre recombinase expression in various eye structures has facilitated these experiments. However, an early expressing, temporally-regulated, optic vesicle-specific Cre line has not been available. In this report, we detail the generation and analysis of a knock-in, inducible Cre line designed to drive recombination specifically within the Rx expression domain. Crossing this line with a reporter line demonstrates that recombination can be mediated within the early optic vesicle and throughout retinal development. Recombination can also be mediated in the Rx-expressing, ventral diencephalon and future posterior pituitary gland. Furthermore, it was demonstrated that dietary doxycycline could effectively modulate Cre activity. This line has the potential to facilitate conditional knock-out experimentation to study early retina and/or posterior pituitary development.

  13. Drug discovery in prostate cancer mouse models.

    Science.gov (United States)

    Valkenburg, Kenneth C; Pienta, Kenneth J

    2015-01-01

    The mouse is an important, though imperfect, organism with which to model human disease and to discover and test novel drugs in a preclinical setting. Many experimental strategies have been used to discover new biological and molecular targets in the mouse, with the hopes of translating these discoveries into novel drugs to treat prostate cancer in humans. Modeling prostate cancer in the mouse, however, has been challenging, and often drugs that work in mice have failed in human trials. The authors discuss the similarities and differences between mice and men; the types of mouse models that exist to model prostate cancer; practical questions one must ask when using a mouse as a model; and potential reasons that drugs do not often translate to humans. They also discuss the current value in using mouse models for drug discovery to treat prostate cancer and what needs are still unmet in field. With proper planning and following practical guidelines by the researcher, the mouse is a powerful experimental tool. The field lacks genetically engineered metastatic models, and xenograft models do not allow for the study of the immune system during the metastatic process. There remain several important limitations to discovering and testing novel drugs in mice for eventual human use, but these can often be overcome. Overall, mouse modeling is an essential part of prostate cancer research and drug discovery. Emerging technologies and better and ever-increasing forms of communication are moving the field in a hopeful direction.

  14. Fulltime biometric mouse design for continuous authentication ...

    African Journals Online (AJOL)

    We formulate a full-time biometric mouse (FBM) design that would ensure thumb positioning and its ergonomics while ensuring comfort and maximum contact with the scanner to enable continuous authentication of the user in a speedy, easy and non-strenuous way. The mouse employs a simple algorithm that ensures ...

  15. Are You a Man or a Mouse?

    DEFF Research Database (Denmark)

    Herrmann, Janne Rothmar

    2008-01-01

    Are you a man or a mouse? This expression is used to encourage someone to be brave when they are frightened of doing something. It is also an expression which bears associations to John Steinbeck's novella Of Mice and Men, the title of which is taken from Robert Burns' poem To a Mouse, which is o...

  16. The wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

    Moser, Jakob Maximilian; Bigini, Paolo; Schmitt-John, Thomas

    2013-01-01

    This review article is focused on the research progress made utilizing the wobbler mouse as animal model for human motor neuron diseases, especially the amyotrophic lateral sclerosis (ALS). The wobbler mouse develops progressive degeneration of upper and lower motor neurons and shows striking...

  17. Alpha-1 antitrypsin protein and gene therapies decrease autoimmunity and delay arthritis development in mouse model

    Directory of Open Access Journals (Sweden)

    Atkinson Mark A

    2011-02-01

    Full Text Available Abstract Background Alpha-1 antitrypsin (AAT is a multi-functional protein that has anti-inflammatory and tissue protective properties. We previously reported that human AAT (hAAT gene therapy prevented autoimmune diabetes in non-obese diabetic (NOD mice and suppressed arthritis development in combination with doxycycline in mice. In the present study we investigated the feasibility of hAAT monotherapy for the treatment of chronic arthritis in collagen-induced arthritis (CIA, a mouse model of rheumatoid arthritis (RA. Methods DBA/1 mice were immunized with bovine type II collagen (bCII to induce arthritis. These mice were pretreated either with hAAT protein or with recombinant adeno-associated virus vector expressing hAAT (rAAV-hAAT. Control groups received saline injections. Arthritis development was evaluated by prevalence of arthritis and arthritic index. Serum levels of B-cell activating factor of the TNF-α family (BAFF, antibodies against both bovine (bCII and mouse collagen II (mCII were tested by ELISA. Results Human AAT protein therapy as well as recombinant adeno-associated virus (rAAV8-mediated hAAT gene therapy significantly delayed onset and ameliorated disease development of arthritis in CIA mouse model. Importantly, hAAT therapies significantly reduced serum levels of BAFF and autoantibodies against bCII and mCII, suggesting that the effects are mediated via B-cells, at least partially. Conclusion These results present a new drug for arthritis therapy. Human AAT protein and gene therapies are able to ameliorate and delay arthritis development and reduce autoimmunity, indicating promising potential of these therapies as a new treatment strategy for RA.

  18. Measurement of recombination in MicroBooNE

    Science.gov (United States)

    Luo, Xiao; Balasubramanian, Supraja; Yang, Tingjun; MicroBooNE Collaboration

    2017-01-01

    MicroBooNE uses the Liquid Argon Time Projection Chamber (LAr TPC) technology to detect neutrino interactions from the Fermilab Booster Neutrino Beam. Traveling through the detector volume, charged particles deposit energy by ionizing the argon and create positive argon ions and electron pairs along their trajectory. The electrons can recombine with an argon ion and reform a neutral atom and, as a result, the measured energy is only a fraction of the total energy lost by the particle. This process is called electron-ion recombination. Understanding this recombination effect is particularly important for performing calorimetry, identifying particle types, and achieving good energy resolution in LAr TPCs. This talk will present the status of MicroBooNE's first recombination measurement obtained with cosmic ray data.

  19. ATR inhibition preferentially targets homologous recombination-deficient tumor cells

    NARCIS (Netherlands)

    Krajewska, M.; Fehrmann, R. S. N.; Schoonen, P. M.; Labib, S.; de Vries, E. G. E.; Franke, L.; van Vugt, M. A. T. M.

    Homologous recombination (HR) is required for faithful repair of double-strand DNA breaks. Defects in HR repair cause severe genomic instability and challenge cellular viability. Paradoxically, various cancers are HR defective and have apparently acquired characteristics to survive genomic

  20. The evolutionary value of recombination is constrained by genome modularity.

    Directory of Open Access Journals (Sweden)

    Darren P Martin

    2005-10-01

    Full Text Available Genetic recombination is a fundamental evolutionary mechanism promoting biological adaptation. Using engineered recombinants of the small single-stranded DNA plant virus, Maize streak virus (MSV, we experimentally demonstrate that fragments of genetic material only function optimally if they reside within genomes similar to those in which they evolved. The degree of similarity necessary for optimal functionality is correlated with the complexity of intragenomic interaction networks within which genome fragments must function. There is a striking correlation between our experimental results and the types of MSV recombinants that are detectable in nature, indicating that obligatory maintenance of intragenome interaction networks strongly constrains the evolutionary value of recombination for this virus and probably for genomes in general.

  1. The Time Scale of Recombination Rate Evolution in Great Apes

    National Research Council Canada - National Science Library

    Stevison, Laurie S; Woerner, August E; Kidd, Jeffrey M; Kelley, Joanna L; Veeramah, Krishna R; McManus, Kimberly F; Bustamante, Carlos D; Hammer, Michael F; Wall, Jeffrey D

    2016-01-01

    We present three linkage-disequilibrium (LD)-based recombination maps generated using whole-genome sequence data from 10 Nigerian chimpanzees, 13 bonobos, and 15 western gorillas, collected as part of the Great Ape Genome Project...

  2. Molecular analysis of intragenic recombination at the tryptophan ...

    Indian Academy of Sciences (India)

    /fulltext/jgen/092/03/0523-0528. Keywords. mutation; recombination; DNA sequence; primary metabolism; trp-3. Abstract. Fifteen different classically generated and mapped mutations at the tryptophan synthetase locus in Neurospora crassa ...

  3. New strategies for genetic engineering Pseudomonas syringae using recombination

    Science.gov (United States)

    Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

  4. Cloning, recombinant expression and characterization of a new ...

    African Journals Online (AJOL)

    Jane

    2011-06-13

    Jun 13, 2011 ... time-of-flight/time-of-flight; HPLC, high-performance liquid chromatography. ... amylase in engineering microorganism may be a better production .... concentration as test substrate for the recombinant APGA1. Hydrolysis test ...

  5. Emergence of recombinant Mayaro virus strains from the Amazon basin.

    Science.gov (United States)

    Mavian, Carla; Rife, Brittany D; Dollar, James Jarad; Cella, Eleonora; Ciccozzi, Massimo; Prosperi, Mattia C F; Lednicky, John; Morris, J Glenn; Capua, Ilaria; Salemi, Marco

    2017-08-18

    Mayaro virus (MAYV), causative agent of Mayaro Fever, is an arbovirus transmitted by Haemagogus mosquitoes. Despite recent attention due to the identification of several cases in South and Central America and the Caribbean, limited information on MAYV evolution and epidemiology exists and represents a barrier to prevention of further spread. We present a thorough spatiotemporal evolutionary study of MAYV full-genome sequences collected over the last sixty years within South America and Haiti, revealing recent recombination events and adaptation to a broad host and vector range, including Aedes mosquito species. We employed a Bayesian phylogeography approach to characterize the emergence of recombinants in Brazil and Haiti and report evidence in favor of the putative role of human mobility in facilitating recombination among MAYV strains from geographically distinct regions. Spatiotemporal characteristics of recombination events and the emergence of this previously neglected virus in Haiti, a known hub for pathogen spread to the Americas, warrants close monitoring of MAYV infection in the immediate future.

  6. Recombination instability and domainisation in Ô-Ge(Au)

    Indian Academy of Sciences (India)

    m ... semiconductor device applications, since the initial equations for both the models are very similar. The recombination .... any large amplitude peak related to a turbulent burst always arises synchronously with electric current oscillations in ...

  7. Charge Recombination Suppressed by Destructive Quantum Interference in Heterojunction Materials

    NARCIS (Netherlands)

    Tempelaar, Roel; Koster, L. Jan Anton; Havenith, Remco W. A.; Knoester, Jasper; Jansen, Thomas L. C.

    2016-01-01

    We show that charge recombination in ordered heterojunctions depends sensitively on the degree of coherent delocalization of charges at the donor acceptor interface. Depending on the relative sign of the electron and hole transfer integrals, such delocalization can dramatically suppress

  8. Purification, biochemical and kinetic properties of recombinant Staphylococcus aureus lipase.

    Science.gov (United States)

    Horchani, Habib; Fendri, Ahmed; Louati, Hanen; Sayari, Adel; Gargouri, Youssef; Verger, Robert

    2012-01-01

    We have compared the purification procedures as well as the biochemical and kinetic properties of wild type (wt-SAL3), untagged recombinant (rec(-His)SAL3), and tagged recombinant (rec(+His)SAL3) purified forms of Staphylococcus aureus lipase (SAL3). We used the pH-stat method (with emulsified tributyrin and olive oil as substrates) and the monomolecular film technique (with the three dicaprin isomers spread in the form of monomolecular films at the air-water interface). The data obtained showed that the recombinant expression process as well as the presence of a his-tag at the N-terminus of recombinant SAL3 affects significantly many biochemical and catalytic properties. The effects of the heterologous expression process on the catalytic properties of the staphylococcal lipases are three times more deleterious than the presence of an N-terminal tag extension.

  9. Automated phylogenetic detection of recombination using a genetic algorithm

    National Research Council Canada - National Science Library

    Kosakovsky Pond, Sergei L; Posada, David; Gravenor, Michael B; Woelk, Christopher H; Frost, Simon D W

    2006-01-01

    .... We propose a model-based framework that uses a genetic algorithm to search a multiple-sequence alignment for putative recombination break points, quantifies the level of support for their locations...

  10. A new strategy for estimating two-locus recombination fractions ...

    Indian Academy of Sciences (India)

    2011-08-19

    locus recombination fractions under some natural inequality restrictions. J. Genet. 90, 275–282]. Introduction. Linkage analysis is used in both human and other biologi- cal studies. Lathrop et al. (1984) discussed the strategies ...

  11. Recombinational Cloning Using Gateway and In-Fusion Cloning Schemes

    Science.gov (United States)

    Throop, Andrea L.; LaBaer, Joshua

    2015-01-01

    The comprehensive study of protein structure and function, or proteomics, depends on the obtainability of full-length cDNAs in species-specific expression vectors and subsequent functional analysis of the expressed protein. Recombinational cloning is a universal cloning technique based on site-specific recombination that is independent of the insert DNA sequence of interest, which differentiates this method from the classical restriction enzyme-based cloning methods. Recombinational cloning enables rapid and efficient parallel transfer of DNA inserts into multiple expression systems. This unit summarizes strategies for generating expression-ready clones using the most popular recombinational cloning technologies, including the commercially available Gateway® (Life Technologies) and In-Fusion® (Clontech) cloning technologies. PMID:25827088

  12. Products of Dissociative Recombination in the Ionosphere

    Science.gov (United States)

    Cosby, Philip

    1996-01-01

    SRI International undertook a novel experimental measurement of the product states formed by dissociative recombination (DR) of O2(+), NO(+), and N2(+) as a function of both electron energy and reactant ion vibrational level. For these measurements we used a recently developed experimental technique for measuring dissociation product distributions that allows both the branching ratios to be accurately determined and the electronic and rovibrational state composition of the reactant ions to be specified. DR is the dominant electron loss mechanism in all regions of the ionosphere. In this process, electron attachment to the molecular ion produces an unstable neutral molecule that rapidly dissociates. For a molecular ion such as O2(+), the dissociation recombination reaction is (1) O2(+) + e yields O + O + W. The atomic products of this reaction, in this case two oxygen atoms, can be produced in a variety of excited states and with a variety of kinetic energies, as represented by W in Eq. (1). These atoms are not only active in the neutral chemistry of the ionosphere, but are also especially important because their optical emissions are often used to infer in situ concentrations of the parent molecular ion and ambient electron densities. Many laboratory measurements have been made of DR reaction rates under a wide range of electron temperatures, but very little is known about the actual distributions among the final states of the atomic products. This lack of knowledge seriously limits the validity and effectiveness of efforts to model both natural and man-made ionospheric disturbances. Bates recently identified major deficiencies in the currently accepted branching ratios for O2(+) as they relate to blue and green line emission measurements in the nocturnal F-region. During our two-year effort, we partially satisfied our ambitious goals. We constructed and operated a variable pressure, electron-impact ion source and a high pressure, hollow-cathode discharge ion

  13. Recombinant interferon regulation of lung fibroblast growth

    Energy Technology Data Exchange (ETDEWEB)

    Elias, J.A.; Freundlich, B.; Rossman, M.D.; Gustilo, K.; Jimenez, S.A.

    1986-03-01

    The authors characterized the effect on human lung fibroblast proliferation of recombinant interferons (gamma (..gamma..), alpha/sub A/ (..cap alpha../sub A/), alpha/sub D/ (..cap alpha../sub D/) and beta (..beta..)). Quiescent and log phase fibroblasts were used. Proliferation was assessed using /sup 3/HTdr uptake and cell counts. ..gamma.. stimulated the /sup 3/HTdr uptake of quiescent cells. Maximal stimulation was seen between 100 and 500 IU/ml. Fibroblasts incubated in 100 IU/ml incorporated 160 +/- 9% as much /sup 3/HTdr as quiescent controls (p < .04). In contrast, ..gamma.. caused a dose dependent inhibition of the /sup 3/HTdr uptake of log phase cells. Fibroblasts incubated in 1000 IU/ml incorporated 41 +/- 9% as much /sup 3/HTdr as log phase controls (p < .02). Unlike ..gamma.., ..cap alpha../sub A/, ..cap alpha../sub D/ and ..beta.. did not stimulate the proliferation of quiescent cells. However, they did inhibit the proliferation of log phase cells. Fibroblasts incubated in 1000 IU/ml of ..cap alpha../sub A/, ..cap alpha../sub D/ and ..beta.. incorporated 64 +/- 10, 81 +/- 4 and 62 +/- 7% as much /sup 3/HTdr as log phase controls (p < .03 for all). ..gamma.., ..cap alpha../sub A/, ..cap alpha../sub D/ and ..beta.. did not stimulate fibroblast prostaglandin E (PGE) production and incubating fibroblasts with indomethacin did not reverse the inhibition of fibroblast proliferation caused by the interferons. Thus, (1) ..gamma.. can stimulate or inhibit fibroblast growth, (2) ..cap alpha../sub A/, ..cap alpha../sub D/ and ..beta.. only inhibit fibroblast growth, (3) the inhibition of fibroblast growth caused by ..gamma.., ..cap alpha../sub A/, ..cap alpha../sub D/ and ..beta.. is largely independent of fibroblast PGE production.

  14. Recombinant ArtinM activates mast cells.

    Science.gov (United States)

    Barbosa-Lorenzi, Valéria Cintra; Cecilio, Nerry Tatiana; de Almeida Buranello, Patricia Andressa; Pranchevicius, Maria Cristina; Goldman, Maria Helena S; Pereira-da-Silva, Gabriela; Roque-Barreira, Maria Cristina; Jamur, Maria Célia; Oliver, Constance

    2016-07-04

    Mast cells are hematopoietically derived cells that play a role in inflammatory processes such as allergy, as well as in the immune response against pathogens by the selective and rapid release of preformed and lipid mediators, and the delayed release of cytokines. The native homotetrameric lectin ArtinM, a D-mannose binding lectin purified from Artocarpus heterophyllus seeds, is one of several lectins that are able to activate mast cells. Besides activating mast cells, ArtinM has been shown to affect several biological responses, including immunomodulation and acceleration of wound healing. Because of the potential pharmacological application of ArtinM, a recombinant ArtinM (rArtinM) was produced in Escherichia coli. The current study evaluated the ability of rArtinM to induce mast cell degranulation and activation. The glycan binding specificity of rArtinM was similar to that of jArtinM. rArtinM, via its CRD, was able to degranulate, releasing β-hexosaminidase and TNF-α, and to promote morphological changes on the mast cell surface. Moreover, rArtinM induced the release of the newly-synthesized mediator, IL-4. rArtinM does not have a co-stimulatory effect on the FcεRI degranulation via. The IgE-dependent mast cell activation triggered by rArtinM seems to be dependent on NFkB activation. The lectin rArtinM has the ability to activate and degranulate mast cells via their CRDs. The present study indicates that rArtinM is a suitable substitute for the native form, jArtinM, and that rArtinM may serve as an important and reliable pharmacological agent.

  15. Biological characterization of a recombinant pseudorabies virus

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, E.; Prieto, C.; Martinez-Lobo, F. J.; Castro, J. M.

    2008-07-01

    In a previous study we obtained and characterized in vitro a novel pseudorabies virus (PRV) variant named gIp2 with a TK, gI/gE, 11k and 28k negative phenotype and a duplication of PK gene. The main objective of the present study was to determine the safety and efficacy, as a vaccine candidate, of this recombinant PRV. For this purpose, we used 24 PRV seronegative three weeks old piglets that were divided into five groups of treatment. Piglets of groups A and B were immunized twice with 10{sup 6}.5 and 10{sup 5}.5 TCID{sub 5}0 of gIp2, respectively; pigs of group C were vaccinated twice with MLV vaccine Auskipra GN and pigs of groups D and E were not immunized and served as infected and uninfected controls, respectively. Four weeks after the second immunization pigs of groups A, B, C and D were challenged by intranasal inoculation of 10{sup 6} TCID{sub 5}0 of the wild type NIA-3 strain of PRV. No adverse reactions or clinical signs were observed in any group after immunization, indicating that the application of up to 10 times the conventional dose included in a commercial vaccine (i.e. 10{sup 5}.5 TCID{sub 5}0) of gIp2 was safe in piglets. Additionally, the inoculation of gIp2 induced an immune response able to provide clinical and virological protection against pseudorabies virus after challenge. In conclusion, the use of gIp2 in piglets as a vaccine virus is safe and induces an immunity comparable to that exerted by commercially available vaccines. (Author) 34 refs.

  16. Clinical targeting recombinant immunotoxins for cancer therapy

    Directory of Open Access Journals (Sweden)

    Li M

    2017-07-01

    Full Text Available Meng Li,1,* Zeng-Shan Liu,1,* Xi-Lin Liu,1,* Qi Hui,2,* Shi-Ying Lu,1 Lin-Lin Qu,1 Yan-Song Li,1 Yu Zhou,1 Hong-Lin Ren,1 Pan Hu1 1Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, China-Japan Union Hospital, The First Hospital, Jilin University, Changchun, 2School of Pharmacy, Wenzhou Medical University, Wenzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Recombinant immunotoxins (RITs are proteins that contain a toxin fused to an antibody or small molecules and are constructed by the genetic engineering technique. RITs can bind to and be internalized by cells and kill cancerous or non-cancerous cells by inhibiting protein synthesis. A wide variety of RITs have been tested against different cancers in cell culture, xenograft models, and human patients during the past several decades. RITs have shown activity in therapy of several kinds of cancers, but different levels of side effects, mainly related to vascular leak syndrome, were also observed in the treated patients. High immunogenicity of RITs limited their long-term or repeat applications in clinical cases. Recent advances in the design of immunotoxins, such as humanization of antibody fragment, PEGylation, and modification of human B- and T-cell epitopes, are overcoming the above mentioned problems, which predict the use of these immunotoxins as a potential therapeutic method to treat cancer patients. Keywords: targeted therapy, hematologic malignancies, solid tumors, vascular leak syndrome, immunogenicity 

  17. Recombinant production of the therapeutic peptide lunasin

    Directory of Open Access Journals (Sweden)

    Kyle Stuart

    2012-02-01

    Full Text Available Abstract Background Lunasin is a chemopreventive peptide produced in a number of plant species. It comprises a helical region with homology to a region of chromatin binding proteins, an Arg-Gly-Asp cell adhesion motif and eight aspartic acid residues. In vitro studies indicate that lunasin suppresses chemical and oncogene driven transformation of mammalian cells. We have explored efficient recombinant production of lunasin by exploiting the Clostridium thermocellum CipB cellulose binding domain (CBD as a fusion partner protein. Results We used a pET28 vector to express a CBD-lunasin fusion with a hexahistidine tag and Tobacco Etch Virus protease site, to allow protease-mediated release of native lunasin. Autoinduction in E. coli BL21 (DE3 Star cells achieved expression of 3.35 g/L of CBD-lunasin fusion protein. The final yield of lunasin was 210 mg/L corresponding to 32% of the theoretical yield. Purification by cellulose binding and nickel affinity chromatography were tested with the latter proving more satisfactory. The effects of CBD-lunasin expression on growth and morphology of the E. coli cells were examined by light and electron microscopy revealing an altered morphology in a proportion of cells. Cell division appeared to be inhibited in these cells resulting in elongated, non-septated cells. Conclusions The use of CBD as a fusion partner gave high protein yields by autoinduction, with lunasin release by TEV protease cleavage. With some optimisation this approach could provide a potentially valuable route for production of this therapeutic peptide. Over-expression in the host cells manifest as a cell division defect in a population of the cells, presumably mimicking some aspect of the chemopreventive function observed in mammalian cells.

  18. Integrated continuous production of recombinant therapeutic proteins.

    Science.gov (United States)

    Warikoo, Veena; Godawat, Rahul; Brower, Kevin; Jain, Sujit; Cummings, Daniel; Simons, Elizabeth; Johnson, Timothy; Walther, Jason; Yu, Marcella; Wright, Benjamin; McLarty, Jean; Karey, Kenneth P; Hwang, Chris; Zhou, Weichang; Riske, Frank; Konstantinov, Konstantin

    2012-12-01

    In the current environment of diverse product pipelines, rapidly fluctuating market demands and growing competition from biosimilars, biotechnology companies are increasingly driven to develop innovative solutions for highly flexible and cost-effective manufacturing. To address these challenging demands, integrated continuous processing, comprised of high-density perfusion cell culture and a directly coupled continuous capture step, can be used as a universal biomanufacturing platform. This study reports the first successful demonstration of the integration of a perfusion bioreactor and a four-column periodic counter-current chromatography (PCC) system for the continuous capture of candidate protein therapeutics. Two examples are presented: (1) a monoclonal antibody (model of a stable protein) and (2) a recombinant human enzyme (model of a highly complex, less stable protein). In both cases, high-density perfusion CHO cell cultures were operated at a quasi-steady state of 50-60 × 10(6) cells/mL for more than 60 days, achieving volumetric productivities much higher than current perfusion or fed-batch processes. The directly integrated and automated PCC system ran uninterrupted for 30 days without indications of time-based performance decline. The product quality observed for the continuous capture process was comparable to that for a batch-column operation. Furthermore, the integration of perfusion cell culture and PCC led to a dramatic decrease in the equipment footprint and elimination of several non-value-added unit operations, such as clarification and intermediate hold steps. These findings demonstrate the potential of integrated continuous bioprocessing as a universal platform for the manufacture of various kinds of therapeutic proteins. Copyright © 2012 Wiley Periodicals, Inc.

  19. Lineage specific recombination rates and microevolution in Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Nightingale Kendra K

    2008-10-01

    Full Text Available Abstract Background The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II and an uncommon lineage (lineage III. While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA for 195 L. monocytogenes isolates. Results Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM and the two virulence genes (actA and inlA. The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that

  20. Recombination Processes on Low Bandgap Antimonides for Thermophotovoltaic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Saroop, Sudesh [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1999-09-01

    Recombination processes in antimonide-based (TPV) devices have been investigated using a technique, in which a Nd-YAG pulsed laser is materials for thermophotovoltaic radio-frequency (RF) photoreflectance used to excite excess carriers and the short-pulse response and photoconductivity decay are monitored with an inductively-coupled non-contacting RF probe. The system has been used to characterize surface and bulk recombination mechanisms in Sb-based materials.