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1
Haas, Elizabeth S. « Genes encoding stable RNAs in Methanothermus fervidus / ». The Ohio State University, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=osu148767164005597.
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Shah, Bindiya. « Identification of genes encoding secreted proteins of schistosomes ». Thesis, University of York, 2000. http://etheses.whiterose.ac.uk/9801/.
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3
Tucker, Sara Louise. « Characterisation of metallothionein-encoding genes in Magnaporthe grisea ». Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395892.
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Thacker, G. « Functional analysis of C.jejuni genes encoding putative peptidases ». Thesis, London School of Hygiene and Tropical Medicine (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536843.
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5
Leech, S. « Molecular studies of neuropeptide-encoding genes in parasitic nematodes ». Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398118.
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6
Vaughan, Tristan John. « Isolation and analysis of genes encoding wheat ribosomal proteins ». Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328181.
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7
Green, Judith Louise. « Genes encoding rhoptry proteins of the malaria parasite plasmodium ». Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300303.
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8
Rapp, Telana. « Isolation and characterisation of genes encoding biopolymer manufacturing enzymes ». Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/19968.
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Thesis (MSc)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Biopolymers exhibit the required material properties to replace conventional, non-biodegradable, petroleum-based polymer products. They have a closed carbon cycle, making them carbon neutral and environmentally friendly. Biopolymers are produced from non-toxic substrates during in vivo enzymatic reactions. Biosynthesis of the most commercially important biopolymers is too complex to be reproduced in in vitro reactions. Identification of the genes responsible for their biosynthesis has been under investigation, with some pathways already elucidated. The genes involved in the biosynthesis of these polymers have been targeted for genetic manipulation to increase productivity, as well as create tailor-made polymers. Novel biopolymers and the genes responsible for their synthesis are of interest for their potential commercial applications. Bacteria produce a wide range of biopolymers and are being implemented as the bio-factories for biopolymer production. They are capable of utilising easily accessible and renewable carbon sources such as sucrose for polymer biosynthesis. Bacteria thus allow for economical production of these environmentally beneficial polymers. In this study, the gene responsible for the production of an unknown biopolymer from an unknown bacterium was identified. The biopolymer producing bacteria were grown on media enriched with sucrose as carbon source, during an expression library screening in a previous study. Expression library technology was used to search for the gene and it was identified as a 424 amino acid levansucrase which had a 100% homology to Leuconostoc mesenteroides M1FT levansucrase (AAT81165.1). Biopolymer analysis revealed that the biopolymer was a levan, a polysaccharide consisting of only fructose molecules with a molecular weight of ± 5 kDa. Analysis of a 516 bp fragment of the 16S rRNA determined that the unknown bacteria were a Pseudomonas species.
AFRIKAANSE OPSOMMING: Bio-polimere besit noodsaaklike materiële eienskappe wat toelaat dat dit konvensionele, nie bio-afbreekbare, petroleum-gebasseerde polimeer produkte kan vervang. Hulle het n geslote koolstof kringloop en is dus koolstof neutraal en omgewingsvriendelik. Bio-polimere word vervaardig van nie-toksiese substrate, gedurende ensiematiese reaksies in vivo. Die belangrikste kommersiële bio-polimere se ensiematiese produksie is te kompleks om in ʼn in vitro reaksie te herproduseer. Ondersoeke tot die identifikasie van die gene wat verantwoordelik is vir die produksie van die polimere is onderweg, en sommige produksie paaie is reeds bekend. Die bekende gene word geteiken vir genetiese manipulasie om hulle produktiwiteit te vermeerder en om unieke polimere te produseer. Unieke bio-polimere en die gene wat vir hul produksie verantwoordelik is, is van belang vir hulle potentiële implimentering in komersiële toepassings. Bakteria produseer ʼn verskeidenheid bio-polimere en word as die bio-fabrieke vir polimeerproduksie geimplimenteer. Hulle kan maklik bekombare koolstofbronne, soos sukrose, gebruik om bio-polimere te produseer. Bakteria laat dus die ekonomiese produksie van hierdie omgewingsvriendelike polimere toe. In hierdie studie word die geen wat verantwoordelik is vir die produksie van ʼn onbekende bio-polimeer van ʼn onbekende bakteria, geidentifiseer. Die bakteria was gevind op media, wat verryk was met sukrose as koolstofbron, tydens ʼn vorige studie, waartydens ʼn uitdrukkingsbiblioteek gesif was op hierdie media. Uitdrukkingsbiblioteek tegnologie was gebruik om die geen te vind. Die geen was geidentifiseer as ʼn 424 aminosuur, homo-fruktose-polimeer produseerende geen, ʼn “levansucrase”. Die geen het ʼn 100% homologie met die M1FT “levansucrase” geen (AAT81165.1) van Leuconostoc mesenteroides gehad. Analise van die bio-polimeer het bepaal dat die polimeer ʼn polisakkaried was, wat slegs uit fruktose molekules bestaan het. Die molekulêre gewig van die polimeer was ± 5 kDa. Analise van ʼn 516 bp fragment van die 16S rRNS het bepaal dat die bakteria van die Pseudomonas spesie afkomstig was.
9
Smillie, David Andrew. « Genes encoding sigma cross-reacting proteins of Escherichia coli ». Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/14435.
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In the course of work aimed at discovering new sigma transcription initiation factors in Escherichia coli, two unknown sigma cross-reacting proteins (SCRP-23 and SCRP-27A) were identified by cross-reaction with antibodies raised against region 2.2 of sigma 70. This thesis describes the mapping, sequencing and characterisation of the corresponding genes. The gene encoding SCRP-23 was located near 652kb on the physical map of the E. coli chromosomes. Its sequence and that of part of a downstream open reading frame were determined, and found to be closely similar to the ahpC and F genes (respectively) of Salmonella typhimurium. These encode the C22 and F52a subunits of the anti-oxidant enzyme, alkylhydroperoxide reductase. The identity of the E. coli genes was further established by their ability when introduced on plasmids into an ahp deletion strain to restore cumene hydroperoxide resistance. Transcription of ahpCF was found to be driven by two promoters: ahpP1 is dependent on activation by the OxyR transcriptional regulator, whilst ahpP2 is independent of this factor. Indeed ahpP2 is located within the OxyR target site, and is repressed when OxyR is activated by oxidation. The gene encoding SCRP-27A, scrP, was located near 3416 kb on the physical map, just 250 bp downstream of arcB. arcB encodes a transmembrane sensor-regulator of respiratory functions.
10
Wallis, Anne Elizabeth. « Identification of Leishmania genes encoding proteins containing tandemly repeating peptides ». Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/29447.
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In order to identify Leishmania proteins which may be immunologically relevant or may play a role in interactions between Leishmania and its mammalian host, a Leishmania major genomic DNA library was constructed in the vector λgt11 and screened with antibodies raised to Leishmania major promastigote membranes. Two recombinant DNA clones were identified which encoded repetitive sequences (Clone 20 and Clone 39). Clone 20 encoded a repetitive peptide of 14 amino acids and clone 39 encoded an unrelated repetitive peptide of 10 amino acids. Analysis of one of these clones, Clone 20, indicated that there were two RNA transcripts of 9500 and 5200 nucleotides expressed which corresponded to this clone in Leishmania major and Leishmania donovani and this expression was not stage-specific. The results of genomic DNA analysis and isolation of additional clones encoding Clone 20 sequences indicated that there were two genes which corresponded to Clone 20 in both Leishmania major and Leishmania donovani and that these genes differed from one another with respect to the number of repeats which they contained. Antibodies against the fusion protein produced by Clone 20 recognized a series of Leishmania major proteins of apparent mol wt 250,000. Analysis of Clone 39 indicated that there was a single transcript of 7500 nucleotides expressed which corresponded to this clone in both Leishmania major and Leishmania donovani and that there was a single gene (or two identical genes) which encoded this transcript.
The genomes of many protozoan parasites exhibit a high degree of plasticity with respect to chromosome size and number. The presence of highly repetitive regions within their DNA may be involved in maintaining this plasticity, allowing the parasite to evolve rapidly under selective pressure. Repetitive regions have been identified within many Plasmodia antigens and have been implicated in the ability of this parasite to evade the host immune system. The presence of Leishmania genes encoding proteins containing tandemly repeating peptides may indicate that these proteins play a similar role in evading the host immune system during the course of Leishmania infections. The possible evolution and functions of repetitive proteins in protozoan parasites is discussed.Medicine, Faculty of
Medical Genetics, Department of
Graduate
11
Kim, Bong-Suk. « Cloning of genes encoding desirable characteristics of dendrobium gatton 'sunray' ». Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941349.
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Currently the breeding of desirable traits in orchid flowers is a lengthy and unpredictable process. A shortened breeding time and a more direct method of introducing specific genetic characteristics could be achieved if more information were available on the specific genes responsible for flower characteristics. In order to identify some of these genes, the genetic relationships between a hybrid, Dendrobium Gatton 'Sunray', and the parent species bred to produce it, D. chrysotoxum Lindley and D. pu/che//um Lindley were examined.Ball State UniversityMuncie, IN 47306These results were supported by Restriction Fragment Length Polymorphisms (RFLPs) observed following amplification of the Internal Transcribed Spacer (ITS) regions of the rDNAs.In order to clone genes responsible for specific flower characteristics, mRNA differential display was performed using total RNA isolated from the leaves, immature flowers, and mature flowers of the hybrid orchid and its two parents. Bands unique to D. Gatton 'Sunray' flower tissue, which were common to the hybrid and a single parent, were excised from a denaturing acrylamide gel. Four of the bands, which represented expressed genes determining inherited flower characteristics, were re-amplified, cloned, and three were sequenced. Partial sequence information obtained for two of the clones was used to search the GenBank database for homologous genes. One of the clones had sequence homology to plant 26S ribosomal genes and the other clone was homologous to sequences encoding regulatory proteins active during development (for example, the human retinoblastoma susceptibility gene or the Caenorhabditis e/egans cosmid R06F6 containing a serine/threonine protein kinase gene).Department of Biology
12
Speight, Richard Alan. « The structure, function and regulation of mycobacterial porin-encoding genes ». Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367873.
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13
Baker, Alison. « Nuclear genes encoding the adenine nucleotide translocator of maize mitochondria ». Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/10708.
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14
Rezenom, Suzie Haile. « Differential Expression of Genes Encoding Secreted Proteins in Penicillium Marneffei ». Youngstown State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1369740920.
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15
Halford, Nigel G. « The structure and expression of the genes encoding the molecular weight subunits of wheat glutenin ». Thesis, Rothamsted Research, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234317.
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16
Jung, Benjamin P. « Discovery and characterization of three genes encoding G protein-coupled receptors ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29320.pdf.
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Di, Carlo Martino. « Calcium signaling and the expression of nuclear genes encoding mitochondrial proteins ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ39188.pdf.
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18
Lindell, Monica. « Expression of Genes Encoding for Drug Metabolism in the Small Intestine ». Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3601.
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19
Rafiq, Sajjad. « The role of common genetic variation in genes encoding inflammatory markers ». Thesis, University of Exeter, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497584.
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Interleukins ILIRA, 1L6R and 1L18 are important cytokines, implicated in ageing processes. Some of these interleukins or their receptors or antagonists already provide targets for treatments. We hypothesized that interleukin related genotypes alter serum concentrations and thereby alter inflammatory profiles in individuals from the general population.
20
Tate, Alison Winifred. « Identification of genes encoding proteins implicated in peroxisomal function and disease ». Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625073.
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21
Liggins, Amanda. « Cloning and characterisation of genes encoding molecular recognition proteins from insects ». Thesis, University of Nottingham, 2001. http://eprints.nottingham.ac.uk/11555/.
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Olfaction is one of the most important senses by which insects obtain information about their environment. In the early stages of olfactory perception in insects, odour molecules are carried across the sensillum lymph by small soluble Odorant Binding Proteins (OBPs). This is followed by activation of the appropriate olfactory receptor, resulting in an electrical impulse, and subsequent degradation of the initial signal. OBPs have been studied in a range of insect orders including Lepidoptera, Diptera and Orthoptera, and this study reports the cloning and characterisation of cDNAs with a potential olfactory role in the vetch aphid, Megoura viciae (Buckton, Homoptera: Aphididiae). Construction and sequencing of antennal cDNA libraries identified two cDNAs, MvicOBP1 and Mv164, which were approximately 0.8kb and 1kb respectively. The amino acid sequence of MvicOBP1 has the spacing pattern of six cysteine residues that is characteristic of insect OBPs, and Mv164 shows similarity to insect cytochrome P450 enzymes. RT-PCR showed that these cDNAs have specific or enhanced expression in the chemosensory tissues of M. viciae, and parallel expression patterns suggest a "linked" function. Related sequences are present and expressed in other aphid species, and sequencing of genomic fragments allowed the partial elucidation of the intron/exon organisation of these genes. Subtracted antennal cDNA libraries identified two cDNAs encoding proteins with significant similarity to insect chemosensory proteins (CSPs), cDNAs encoding Juvenile Hormone Binding Proteins (JHBPs), and a tissue-specific cDNA with a potential carrier role. These, coupled with the OBPs, add evidence to the suggestion that there is an insect superfamily of binding proteins. A PBP from Bombyx mori (BmorPBP1) was used as a model system for in vitro expression of an insect OBP and subsequent characterisation of the recombinant protein. Four forms of this protein, identified through their interaction with an anti-BmorPBP antibody, were resolved by isoelectric focusing.
22
Miskelly, I. R. « Comparative analysis of parasitic nematode neuropeptide and neuropeptide receptor encoding genes ». Thesis, Queen's University Belfast, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432533.
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23
Hayes, Lyn J. « Molecular cloning of genes encoding variant surface antigens of Borrelia duttonii ». Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47469.
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Morgan, Dale. « Molecular analysis of genes encoding resistance to Cationic Biocides in staphylococci ». Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/2467.
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Bacterial resistance to non-antibiotic agents is being increasingly studied. Plasmid-mediated resistance to cationic agents, which are important biocides, has been described in antibiotic-resistant Staphylococcus aureus. Multi-resistant Staphylococcus aureus (MRSA) are often found to express resistance to a range of cationic biocides including quaternary ammonium compounds (QACs), biguanides, diamidino compounds, cationic dyes and nuclear stains. Three resistance determinants, qacA, qacB and smr genes, have been identified that confer resistance to cationic biocides in staphylococci. These genes encode multi-drug efflux pumps that remove the cationic biocides from the cytoplasm using a membrane bound pumping mechanism dependent on the cell's proton-motive force (PMF). This prevents the build up of lethal concentrations of cationic compounds within the cytoplasm avoiding cell death.This research project has focused on the S. aureus strain WBG4364, a transcipient strain carrying the cationic biocide resistant plasmid pWBG1773. The plasmid encodes resistance to several QACs, including benzalkonium chloride and CTAB, and cationic dyes rhodamine 6G, crystal violet and safranin O but not to the dye ethidium bromide and therefore differing from other cationic biocide resistant plasmids previously identified in staphylococci (Emslie et al. 1986). This unique phenotype was further classified in this study alongside those strains carrying the qac gene families, qacA/B and smr.Plasmid pWBG1773 was cloned, sequenced and analysed to reveal a unique plasmid of 2,916 bp in length. Plasmid pWBG1773 was placed with the pC194 family of rolling-circle replicating plasmids. This family appear to be largely composed of interchangeable cassette structures.The plasmid was found to carry three ORFs, designated ORF1, ORF2 and ORF3. ORF1 was homologous to rep genes of small staphylococcal plasmids belonging to the pC194 rolling-circle replication family and has been redefined as repWBG1773. ORF2 was found to have no similarity to any proteins of known function in the GenBank database whereas ORF3 was found to have homology to the marR gene, a regulator of the multiple antibiotic resistance (mar) operon of Gram-negative organisms. MIC analysis of these ORFs found both ORF2 and ORF3 were essential for expression of resistance to cationic biocides. The exact ORF2 sequence required for resistance to be expressed was reduced to only 141 nt in size. This translated to a 47 aa sequence that contained a hydrophobic C-terminus indicating ORF2 to be a membrane-bound protein. The aa sequence of ORF3 contained a helix-turn-helix motif characteristic of the DNA binding domains of MarR-like proteins. Further analysis of pWBG1773 identified a putative 'marbox', a binding site for the homologous transcriptional activators of mar, within the ORF2 sequence. This indicated that ORF3 was binding to the 'marbox' sequence and activating transcription. Induction studies have not been able to ascertain any compounds capable of interacting with the ORF3 regulatory protein resulting in induction of cationic biocide resistance. Each ORF when analysed alone had no effect on the expression of cationic biocide resistance and it is thought that a efflux pump was not involved. This is further corroborated by the CCCP efflux experiments performed in an attempt to determine the mechanism of resistance. The unique ORFs of plasmid pWBG1773 appears to encode a novel cationic biocide resistance phenotype and mechanism.MRSA strains from all around the world were analysed to determine if they possessed sequences homologous to ORF2 and ORF3. Sequences sharing a high degree of homology to ORF2 and/or ORF3 were detected in several MRSA strains including strains sensitive to all cationic biocides tested. These findings suggest that the appearance of ORF2 and ORF3 sequences in MRSAs was not an isolated event and the fact that some MRSAs do not carry both ORF2 and ORF3 sequences simultaneously indicates that these genes have another role that does not involve expression of resistance to cationic biocides.Bacteria are noteworthy for their remarkable ability to adapt to changes in their environments and possess an impressive set of tools with which to adjust the blueprint of the cell to this change. The acquisition of a single system that may decrease a potential pathogenic organisms susceptibility to a wide range of cationic biocides, such as seen in pWBG1773, poses a clinical threat, one that needs to be thoroughly investigated.
25
Morgan, Dale. « Molecular analysis of genes encoding resistance to Cationic Biocides in staphylococci ». Curtin University of Technology, School of Pharmacy, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17463.
Texte intégralRésumé :
Bacterial resistance to non-antibiotic agents is being increasingly studied. Plasmid-mediated resistance to cationic agents, which are important biocides, has been described in antibiotic-resistant Staphylococcus aureus. Multi-resistant Staphylococcus aureus (MRSA) are often found to express resistance to a range of cationic biocides including quaternary ammonium compounds (QACs), biguanides, diamidino compounds, cationic dyes and nuclear stains. Three resistance determinants, qacA, qacB and smr genes, have been identified that confer resistance to cationic biocides in staphylococci. These genes encode multi-drug efflux pumps that remove the cationic biocides from the cytoplasm using a membrane bound pumping mechanism dependent on the cell's proton-motive force (PMF). This prevents the build up of lethal concentrations of cationic compounds within the cytoplasm avoiding cell death.This research project has focused on the S. aureus strain WBG4364, a transcipient strain carrying the cationic biocide resistant plasmid pWBG1773. The plasmid encodes resistance to several QACs, including benzalkonium chloride and CTAB, and cationic dyes rhodamine 6G, crystal violet and safranin O but not to the dye ethidium bromide and therefore differing from other cationic biocide resistant plasmids previously identified in staphylococci (Emslie et al. 1986). This unique phenotype was further classified in this study alongside those strains carrying the qac gene families, qacA/B and smr.Plasmid pWBG1773 was cloned, sequenced and analysed to reveal a unique plasmid of 2,916 bp in length. Plasmid pWBG1773 was placed with the pC194 family of rolling-circle replicating plasmids. This family appear to be largely composed of interchangeable cassette structures.The plasmid was found to carry three ORFs, designated ORF1, ORF2 and ORF3. ORF1 was homologous to rep genes of small staphylococcal ++plasmids belonging to the pC194 rolling-circle replication family and has been redefined as repWBG1773. ORF2 was found to have no similarity to any proteins of known function in the GenBank database whereas ORF3 was found to have homology to the marR gene, a regulator of the multiple antibiotic resistance (mar) operon of Gram-negative organisms. MIC analysis of these ORFs found both ORF2 and ORF3 were essential for expression of resistance to cationic biocides. The exact ORF2 sequence required for resistance to be expressed was reduced to only 141 nt in size. This translated to a 47 aa sequence that contained a hydrophobic C-terminus indicating ORF2 to be a membrane-bound protein. The aa sequence of ORF3 contained a helix-turn-helix motif characteristic of the DNA binding domains of MarR-like proteins. Further analysis of pWBG1773 identified a putative 'marbox', a binding site for the homologous transcriptional activators of mar, within the ORF2 sequence. This indicated that ORF3 was binding to the 'marbox' sequence and activating transcription. Induction studies have not been able to ascertain any compounds capable of interacting with the ORF3 regulatory protein resulting in induction of cationic biocide resistance. Each ORF when analysed alone had no effect on the expression of cationic biocide resistance and it is thought that a efflux pump was not involved. This is further corroborated by the CCCP efflux experiments performed in an attempt to determine the mechanism of resistance. The unique ORFs of plasmid pWBG1773 appears to encode a novel cationic biocide resistance phenotype and mechanism.MRSA strains from all around the world were analysed to determine if they possessed sequences homologous to ORF2 and ORF3. Sequences sharing a high degree of homology to ORF2 and/or ORF3 were detected in several MRSA strains including strains sensitive to all cationic ++
biocides tested. These findings suggest that the appearance of ORF2 and ORF3 sequences in MRSAs was not an isolated event and the fact that some MRSAs do not carry both ORF2 and ORF3 sequences simultaneously indicates that these genes have another role that does not involve expression of resistance to cationic biocides.Bacteria are noteworthy for their remarkable ability to adapt to changes in their environments and possess an impressive set of tools with which to adjust the blueprint of the cell to this change. The acquisition of a single system that may decrease a potential pathogenic organisms susceptibility to a wide range of cationic biocides, such as seen in pWBG1773, poses a clinical threat, one that needs to be thoroughly investigated.
26
Roper, David Ian. « Molecular analysis of an aromatic degradative pathway : studies on the genes and enzymes for homoprotocatechuate degradation from Escherichia coli C ». Thesis, University of Leicester, 1990. http://hdl.handle.net/2381/35141.
Texte intégralRésumé :
The homoprotocatechuate degradative pathway of Escherichia coli C contains two isomerisation reactions with chemically similar intermediates, which were thought to be catalysed by distinct but genetically linked enzymes. The possibility that these two isomerases may have arisen from the same ancestral precursor, given their similar substrate structures and close physical location of their genes, was investigated by nucleotide sequencing and purification of the individual enzymes. The purified proteins are of very different subunit molecular weight and have been shown by kinetic measurements to be specific for their respective substrates. The two isomerisation events are separated by an enzyme catalysed decarboxylation and it has been shown that the second isomerisation and the decarboxylation reactions are distinct activities of the same protein subunit. Comparison of the amino acid sequence of the latter with that of the first isomerase of the pathway, reveals a very low level of similarity, suggesting that the two enzymes are unlikely to be derived from a common ancestor. Subcloning of the rest of hpc gene cluster has revealed that the gene order and direction of transcription are not as previously reported. All the genes for the pathway enzymes are transcribed in the same direction and are subject to negative regulation by a protein which appears to be transcribed in the opposite direction. A putative operator site to which the regulatory protein could bind has been located in the same region as a mapped promoter for the pathway genes, which also contains a binding site for the catabolite activator protein. Pairwise comparison of the amino acid sequences of the rest of the Hpc enzymes have shown only low levels of similarity. However, the single dehydrogenase enzyme of the pathway is similar to isoforms of human aldehyde dehydrogenase. The subcloning procedures used in this study have enabled high level expression of several of the pathway enzymes. This has enabled preliminary crystallographic analysis of the isomerase and decarboxylase/isomerase enzymes.
27
Anderson, Gordon James. « Molecular characterisation of the PRP8 protein on Saccharomyces cerevisiae and identification of an analogue in HeLa cells ». Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/11287.
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Winter, Andreas. « Genomic characterization of genes encoding diacylglycerol acyltransferase activity in cattle and swine ». [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969380909.
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Soodeen-Karamath, Sharon. « Analysis of the chicken genome for genes encoding embryonic stem cell indicators ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/NQ47412.pdf.
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Fajardo-Solache, Norma. « Detection of genes encoding glucosyl-transferases in Lactobacillus rhamnosus ATCC 9595 (eps+) ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ41896.pdf.
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Garneau, Edith. « Synthetic lethal relationships of the genes encoding the p24 family of proteins ». Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82238.
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The highly conserved p24 family of proteins are abundant components of the early secretory pathway, although their specific function remains unclear. In the yeast Saccharomyces cerevisiae, deletion of the eight members of this family results in no marked phenotype, whereas in mice, deletion of a single p24 family member, p23, results in embryonic lethality. In addition, in the fly Drosophila melanogaster, two of the nine p24 proteins have been shown to be necessary for dorsoventral patterning of the embryo.Here, I attempt to determine the function of these proteins by finding new genetic interactors of the p24s using a synthetic genetic array (SGA) analysis in yeast. 44 yeast non-essential genes, when deleted, were identified as being synthetically lethal or sick with the p24s. Many of these interactors are involved in the secretory pathway. To determine the causes of cell death or growth reduction of the double deletion mutants, I studied their ability to secrete the ER protein Kar2p. In many cases of these double deletion mutant strains, Kar2p secretion was exacerbated compared to the p24 deletion alone. This may reflect the loss of fidelity of the transport between the endoplasmic reticulum (ER) and the Golgi apparatus as well as ER retention.
32
Boucher, Catherine Ann. « Identification and characterisation of two human homeodomain encoding genes : DMAHP and Six1 ». Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244265.
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Bhandari, Manju. « Molecular characterisation of the cluster of genes encoding the botulinum neurotoxin complex ». Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389656.
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Bhambra, Gurpreet Kaur. « Characterisation of carnitine acetyltransferase-encoding genes in the rice blast fungus Magnaporthegrisea ». Thesis, University of Exeter, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425287.
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Spathaky, Jane Mary. « A novel method for the isolation of genes encoding peroxisomal matrix proteins ». Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361693.
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Moyo, Mukani. « Molecular and phenotypic characterisation of grapevines expressing non-vinifera PGIP encoding genes ». Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6825.
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Thesis (MSc)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: Plants are constantly exposed to biotic and abiotic stress inducing factors that threaten their existence. Biotic factors such as pathogens are the cause of huge yield losses to crop plants worldwide with fungal pathogens debatably constituting the worst damage. Fungal pathogens such as Botrytis cinerea, which has a wide host range, release cell wall degrading enzymes called endopolygalacturonases (ePGs) during plant infection. These ePGs break down the pectin component of the cell wall, thus providing an entry route, as well as nutrients for the fungus. Plants have evolved mechanisms to counteract and suppress the action of the ePGs. This is achieved through the action of cell wall associated proteins called polygalacturonaseinhibiting proteins, PGIPs. PGIPs directly inhibit ePGs and their inhibitory action also prolongs the existence of longer chain oligogalacturonide residues which are believed to elicit a cascade of defence responses. In grapevine, a PGIP encoding gene, VvPGIP1, was previously isolated and characterised. VvPGIP1, as well as nine non-vinifera grapevine PGIPs have been expressed in tobacco and shown to be potent antifungal proteins that caused the transgenic tobacco to have strong resistance phenotypes against Botrytis in whole plant infection assays. Following on the tobacco study, two of the non-vinifera PGIPs were expressed in cultivars of the susceptible Vitis vinifera. Characterisation of the putative transgenic population showed that transgene integration was successful, the transgenes were being expressed and there were at least 29 transgenic lines with independent integration events. The transgenic lines were confirmed to have active PGIPs (transgene-derived) in their leaves. Crude protein extracts from 22 lines exhibited 100% inhibition against crude B. cinerea PGs (BcPGs). The plant lines with positive transgene integration, expression, independent integration events and exhibiting 100% transgene-derived PGIP activity were further selected for whole plant and detached leaf antifungal assays where they were challenged with B. cinerea. The whole plant infection assay showed that expression of the non-vinifera PGIPs in V. vinifera promotes susceptibility to B. cinerea, not resistance. This surprising result could perhaps be explained by a quicker and stronger recognition between the pathogen and the host and the stronger activation of defence responses in the host. A more active hypersensitive response in the host would benefit Botrytis being a necrotroph. The type of lesions and the onset and speed of lesion development observed on the transgenics lines versus the wild type support this possibility. Knowledge gaps with regards to the efficiency of the ePG inhibition by the nonvinifera PGIPs during infection of grapevine tissue; the potential changes that might be caused by expressing PGIPs in a grapevine host with a native PGIP with high homology to the transgenes (including potential gene silencing) and the potential impact on defence signalling and defence responses all provides further avenues of study to elucidate this very interesting phenotype further. Overall, this study provides a comprehensively characterised population of transgenic plants that provides useful resources for in vivo analysis of PGIP function in defence, where the host plant harbours a native copy of the PGIP encoding gene.
AFRIKAANSE OPSOMMING: Plante word voortdurend blootgestel aan biotiese en abiotiese faktore, wat stres veroorsaak en hul bestaan bedreig. Biotiese faktore, soos patogene, veroorsaak groot verliese in wêreldwye gewasopbrengste, met swampatogene wat moontlik die grootste skade veroorsaak. Swampatogene, soos Botrytis cinerea, wat ‘n wye reeks gasheerplante kan infekteer, stel selwand-afbrekende ensieme tydens plantinfeksie vry, wat as endo-poligalakturonases (ePG’s). bekend staan. Hierdie ePG’s breek die pektienkomponent van die selwand af, wat gevolglik as ‘n ingangspunt dien,asook voedingstowwe vir die swam verskaf. Plante het meganismes ontwikkel om die aktiwiteit van hierdie ePG’s te bekamp en te onderdruk. Die aktiwiteit van die selwand-geassosieërde proteïene, genaamd poligalakturonase-inhiberende proteïene (PGIP’s), speel hier ‘n rol. PGIP’s inhibeer ePG’s direk en hul inhiberende aktiwiteit verleng ook die bestaan van langketting oligogalakturoniedresidu’s, wat blykbaar ‘n kaskade van weerstandsreaksies kan inisieer. ‘n PGIP-koderende geen, VvPGIP1, is voorheen uit wingerd geïsoleer en gekarakteriseer. VvPGIP1, asook nege nie-vinifera wingerd-PGIP’s is voorheen in tabak uitgedruk en bevestig as proteïene met sterk anti-swamaktiwiteit, soos bevestig deur die bevinding dat die transgeniese tabak ‘n weerstandsfenotipe teen Botrytis in heelplant-infeksietoetse het. Ná die tabakstudie is twee van die nie-vinifera PGIP’s uitgedruk in vatbare V. vinifera-kultivars. Karakterisering van die vermeende transgeniese bevolking het getoon dat die transgeen-integrasie suksesvol was, dat die transgeen uitgedruk word en dat daar ten minste 29 transgeniese lyne met onafhanklike integrasie gebeurtenisse geskep is. Daar is verder bevestig dat die transgeniese lyne aktiewe PGIP’s (transgeen-afkomstig) in hul blare het. Ongesuiwerde proteïenekstrakte van 22 lyne het 100% inhibisie teen ‘n mengsel van ongesuiwerde B. cinerea PGs (BcPGs) getoon. Die plantlyne met positiewe transgeenintegrasie en -uitdrukking, asook onafhanklike integrasiegebeure en wat 100% transgeen-afkomstige PGIP-aktiwiteit getoon het, is verder aan heel-plant en verwyderde blaarswaminfeksies met B cinerea onderwerp. Die heelplantinfeksietoetse het getoon dat uitdrukking van nie-vinifera PGIP’s in V. vinifera ‘n toename, in plaas van ‘n afname, in vatbaarheid teen B. cinerea veroorsaak. Hierdie verbasende resultaat kan moontlik toegeskryf word aan ‘n vinniger en sterker herkenningsreaksie tussen patogeen en gasheer en die moontlike sterker stimulering van weerstandsreaksies in die gasheer. ‘n Meer aktiewe hipersensitiewe reaksie in die gasheer sal tot die voordeel van Botrytis, wat ‘n nektrotroof is, wees. Die tipe letsel, asook die aanvang en spoed van letselontwikkeling wat waargeneem is in transgeniese lyne teenoor die wilde-tipe ondersteun hierdie moontlikheid. Gapings in kennis ten opsigte van die doeltreffendheid van die ePG-inhibisie deur die nievinifera PGIP’s tydens infeksie van wingerdweefsel, die moontlike veranderinge (insluitend ‘n moontlike geenuitdowingseffek) wat veroorsaak kan word deur die uitdrukking van PGIP-gene in ‘n kultivar met ‘n inheemse en baie homoloë PGIP-geen, kon ‘n invloed op weerstandseine en weerstandsreaksies gehad het. Hierdie aspekte lewer verdere studiemoontlikhede om hierdie interessante fenotipe verder te verklaar.Algeheel lewer hierdie studie ‘n breedvoeriggekarakteriseerde bevolking trangeniese plante, wat dien as nuttige hulpbronne vir in vivoanalise van PGIP se funksie in siekteweerstandbiedendheid, veral waar die gasheerplant ‘n inheemse kopie van die PGIP-koderende geen huisves.
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Jasrapuria, Sinu. « Tribolium castaneum genes encoding proteins with the chitin-binding type II domain ». Diss., Kansas State University, 2011. http://hdl.handle.net/2097/12017.
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Doctor of PhilosophyDepartment of Biochemistry
Subbarat Muthukrishnan
The extracellular matrices of cuticle and peritrophic matrix of insects are composed mainly of chitin complexed with proteins, some of which contain chitin-binding domains. This study is focused on the identification and functional characterization of genes encoding proteins that possess one or more copies of the six-cysteine-containing ChtBD2 domain (Peritrophin A motif =CBM_14 =Pfam 01607) in the red flour beetle, Tribolium castaneum. A bioinformatics search of T. castaneum genome yielded previously characterized chitin metabolic enzymes and several additional proteins. Using phylogenetic analyses, the exon-intron organization of the corresponding genes, domain organization of proteins, and temporal and tissue-specificity of expression patterns, these proteins were classified into three large families. The first family includes 11 proteins essentially made up of 1 to 14 repeats of the peritrophin A domain. Transcripts for these proteins are expressed only in the midgut and only during feeding stages of development. We therefore denote these proteins as “Peritrophic Matrix Proteins” or PMPs. The genes of the second and third families are expressed in cuticle-forming tissues throughout all stages of development but not in the midgut. These two families have been denoted as “Cuticular Proteins Analogous to Peritrophins 3” or CPAP3s and “Cuticular Proteins Analogous to Peritophins 1” or CPAP1s based on the number of ChtBD2 domains that they contain. Unlike other cuticular proteins studied so far, TcCPAP1-C protein is localized predominantly in the exocuticle and could contribute to the unique properties of this cuticular layer. RNA interference (RNAi), which down-regulates transcripts for any targeted gene, results in lethal and/or abnormal phenotypes for some, but not all, of these genes. Phenotypes are often unique and are manifested at different developmental stages, including embryonic, pupal and/or adult stages. The experiments presented in this dissertation reveal that while the vast majority of the CPAP3 genes serve distinct and essential functions affecting survival, molting or normal cuticle development. However, a minority of the CPAP1 and PMP family genes are indispensable for survival under laboratory conditions. Some of the non-essential genes may have functional redundancy or may be needed only under special circumstances such as exposure to stress or pathogens.
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Godwin, Rosamond Mary. « Cloning and characterisation of genes encoding phosphate and sulphate transporters from rice / ». St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16400.pdf.
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Olive, Mark R. « Wheat starch biosynthesis : organ-specific expression of genes encoding ADP-glucose pyrophosphorylase ». Thesis, University of Warwick, 1988. http://wrap.warwick.ac.uk/109860/.
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Wheat endosperm ADP-glucose pyrophosphorylase has been purified approximately 70-fold by two different procedures. The enzyme is composed of four subunits of identical molecular weight (51,000). Antibodies prepared against the denatured 51 kD subunit of wheat endosperm ADP-glucose pyrophosphorylase recognise a 48 kD polypeptide in soluble protein extracts of wheat leaves, suggesting that wheat leaf and wheat endosperm ADP-glucose pyrophosphorylases may be the products of different genes. Two primary translation products of wheat endosperm ADP-glucose pyrophosphorylase mRNA have been Identified by immunoprecipitation of the nascent polypeptides with anti-wheat endosperm ADP-glucose pyrophosphorylase serum. The ADP-glucose pyrophosphorylase primary translation products have apparent molecular weights of 61,000 and 53,000. The 61 kD polypeptide Is found associated with membrane-bound polysomal RNA from wheat endosperm, while the smaller 53 kD polypeptide has been found associated almost exclusively with free polysomes. A cDNA clone (WL:AGA.l) encoding wheat leaf ADP-glucose pyrophosphorylase has been Isolated from a Xgtll expression library, by immunological screening with anti-spinach leaf ADP-glucose pyrophosphorylase serum. The WL:AGA.l cDNA Is 948 bp long and contains approximately 55% of the complete wheat leaf ADP-glucose pyrophosphorylase mRNA sequence, estimated from Northern blot experiments. A wheat endosperm cDNA library, consisting of 1.6x10s bacteriophage particles, was subsequently constructed in the Xgtll expression vector. Six clones hybridising to the cDNA insert of clone WL:AGA.l were isolated from the wheat endosperm cDNA library. The longest of these wheat endosperm ADP-glucose pyrophosphorylase cDNAs, clone WE:AGA.7, is nearly full-length (1798 bp), indicated by Northern blot analysis of wheat endosperm mRNA, coupled in vitro transcription and translation of the cDNA, and nucleotide sequence analysis. Southern hybridisation analysis and restriction enzyme mapping indicated that the wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs and genes are members of two distinct sub-families, expressed in an organ-specific manner. Southern blot analysis of wheat genomic DNA has been performed using the WE:AGA.7 and WL:AGA.l cDNA inserts as probes. This analysis indicated that each gene sub-family consists of approximately 2-5 genes. In addition, restriction enzyme mapping of wheat endosperm ADP-glucose pyrophosphorylase cDNAs revealed the presence of two classes of that sequence, indicating the existence of at least two wheat endosperm ADP-glucose pyrophosphorylase genes. Subsequent nucleotide sequence comparison of wheat leaf and wheat endosperm ADP-glucose pyrophosphorylase cDNAs Indicates that there is approximately 55% identity between them. In contrast, the wheat endosperm cDNAs are very closely related. Members of each class of endosperm cDNA, represented by clones WE:AGA.3 and WE:AGA.7, are 96% Identical. The derived amino acid sequences of wheat leaf and endosperm ADP-glucose pyrophosphorylases were determined from the nucleotide sequences of the corresponding cDNAs. These sequences are approximately 24% identical to the amino acid sequences of E.coli ADP-glucose pyrophosphorylase and 40% identical to the rice endosperm ADP-glucose pyrophosphorylase. The structure-function relationships pf substrate, activator, and inhibitor binding on the ADP-glucose pyrophosphorylase enzyme are discussed.
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Taboada, Eduardo N. « Molecular cloning of three genes encoding SNF1/AMPK protein kinases from Drosophila melanogaster ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0012/NQ52279.pdf.
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Greenwood, Michael T. « Isolation and characterization of Dictyostelium discoideum genes encoding a common proline-rich region ». Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39517.
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CABP1 is a cAMP-binding protein found in Dictyostelium discoideum. Anti-CABP1 monoclonal antibody cross-reacts with several polypeptides. The gene encoding CABP1, capA, cross-hybridizes to seven genomic fragments on a genomic DNA Southern blot. Clones representing four different capA-related sequences were obtained by screening both cDNA and genomic libraries with the anti-CABP1 monoclonal antibody and with a capA cDNA. Sequence analysis revealed that the structural similarities between CABP1 and two CABP1-related polypeptides are restricted to a region highly enriched for proline, glycine, glutamine, and tyrosine residues. One of these capA-related sequences encodes the p24 actin-binding protein and the other encodes a homologue of human annexin VII. The levels of the p24 transcript were found to decrease in response to the addition of extracellular cAMP and to increase in the presence of the protein synthesis inhibitor cycloheximide. As a preliminary step towards understanding the function of annexin VII, specific antibodies were generated. Immunoblot analysis revealed the existence of two polypeptides with sizes expected for the two products of the alternatively spliced annexin VII encoding gene.
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Teverson, Rachel. « The differential expression of the genes encoding glutamine synthetase in developing root modules ». Thesis, Durham University, 1990. http://etheses.dur.ac.uk/5958/.
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Glutamine synthetase (GS) is one of the key enzymes involved in the assimilation of ammonia into organic nitrogen in plants. It is important in legume root nodules where ammonia, produced by the Rhizobium-legume symbiosis, is converted to organic nitrogen before it can be transported to other parts of the plant. In Phaseolus vulgaris three cytosolic and one plastidic GS polypeptide have been identified. One or more of these polypeptides assemble to form distinct octameric GS isoenzymes. GS activity increases significantly in P. vulgaris during nodulation and this is associated with the Increased (or repressed) expression of the three cytosclic polypeptide genes jln-a, gln-β and gln-γ. The temporal and spatial pattern of mRNA and protein distribution of these genes has been investigated using in situ hybridation and immunocytochemistry. An in situ hybridization protocol has been established using photobiotinylated cRNA probes, visualised with alkaline phosphatase, or streptavidin gold with silver enhancement. The fixation, embedding, section pretreatments and hybridization conditions have all been optimized for legume root nodule sections, the mRNA distributions corresponding to the gln-α, gln-β and gln-γ genes within P. vulgaris root-nodule sections indicate that the the assembly of the GS isoenzymes is at least partially controlled by the differential temporal and spatial expression of these genes throughout the nodule tissues during nodulation. These results have been compared with the expression of the β- glucuronidase (GUS) gene fused with the 5' flanking regions of the P. vulgaris GS genes in chimaeric Lotus corniculatus plants. The GUS expression was demonstrated by the optimized in situ hybridization tecniques in conjunction with immunocytoeheinica1 and GUS histochemical localization tecniques. Results indicate the control of GS gene expression is at the transcriptional level and at least partially determined by the 5' flanking regions of these genes.
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Yeo, Giles See How. « A study of genes encoding complement-related proteins in the pufferfish Fugu rubripes ». Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624883.
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Lancaster, Holli Louise. « The persistence and genetic support of genes encoding antibiotic resistance in oral bacteria ». Thesis, University College London (University of London), 2005. http://discovery.ucl.ac.uk/1444918/.
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Antibiotic-resistant bacteria present a serious public health threat and studies investigating the prevalence of antibiotic-resistant bacteria and the genes encoding for antibiotic resistance (GEAR) are essential. Such studies help us to understand how antibiotic-resistant bacteria and GEAR are obtained, transferred and maintained within a population. The aim of this study was to identify the prevalence and maintenance of antibiotic-resistant bacteria in the oral microbiota of children aged 4-6 years who had not previously taken antibiotics. Bacteria resistant to penicillin, ampicillin, tetracycline and erythromycin were widespread among the children studied. Tetracycline-resistant bacteria were found in 98% of the children sampled and the tetracycline resistance determinants most responsible for this resistance were tet(M) and tet(W). The tetracycline-resistant bacteria were maintained within 15 children over a period of twelve months. In three of these children the tet(M) gene was found to persist in a variety of genera and this was found to be contained within a Tn9/6-like element by Southern blot analysis. The tetracycline resistance determinant tet(S) was found for the first time in Streptococcus intermedius . It was found to be transferable to Enterococcus faecalis and other Streptococcus spp. by filter matings. The tet(S) gene was shown to be present on a novel Tn9/f5-like element designated Tn97r5S. The similarities between Tn916 and Tn976S included the presence of conjugative and excision and integration modules. However the tet(M) in Tn976 had been completely replaced by tet(S) in Tn9/f5S. The gene tet(32) was also found for the first time in Streptococcus parasanguinis and Eubacterium saburreum, previously it had been found in a human colonic bacterium K10. The upstream region of the oral tet(32) gene in E. saburreum 41.2T.2 was found to be more closely related to upstream sequences of tet(W) in Roseburia sp. A2-123, upstream sequences of tet(W) within TnB1230 (originally isolated from Butyrivibrio fibrisolvens ) and orf!4, orf25 and orf26 from Tn5397. This work provides further evidence that antibiotic-resistant bacteria are prevalent in the oral microbiota of children and that the genes responsible, especially those encoding resistance to tetracycline, can be maintained in the oral microbiota even when the children have not been directly exposed to antibiotics. These findings show that tetracycline resistance determinants can be mosaic in structure and can be easily transferred due to their containment within conjugative transposons. Such elements then undergo evolutionary changes, whereby recombination of the conjugative transposon modules result in new genetic elements.
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Villedieu, Aurelie. « Detection and characterisation of genes encoding antibiotic resistance in the cultivable oral microflora ». Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1445139/.
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The emergence of antibiotic-resistant bacteria has become a major threat to public health. The increased use of antibiotics has selected for the dissemination of antibiotic resistance genes between organisms from different species and different genera. There is a large body of evidence that the indigenous microbiota can act as a reservoir of antibiotic-resistant bacteria. However little is known about the molecular basis for this in bacteria from the oral cavity. Therefore the aim of this work was to determine the prevalence of antibiotic-resistant bacteria and antibiotic resistance genes in the cultivable oral microbiota. Saliva and plaque samples were taken from each of 60 healthy adults who had not taken any antibiotics during the previous three months. Each sample was plated onto antibiotic-containing media to quantitate and identify antibiotic-resistant strains. All of the individuals harboured bacteria resistant to erythromycin, gentamicin, vancomycin and tetracycline. Only 4 individuals (7%) did not have any cultivable bacteria resistant to amoxycillin. Oral bacteria resistant to gentamicin were the most commonly isolated (constituting 23% of total cultivable oral bacteria) followed by erythromycin (18% of the total viable count), vancomycin (16% of the total viable count), tetracycline (10% of the total viable count) and amoxycillin (4% of the total viable count). Multiply-resistant bacteria were found with 55% of tetracycline-resistant isolates being resistant also to erythromycin and 6% resistant also to both amoxycillin and erythromycin. The most prevalent genes encoding tetracycline and erythromycin resistance were tet(M), tet(W), tet(0), and mef and erm(B) respectively. In some cases, tet(M) and ermB were contained within a Tn/5 5-like conjugative transposon and could be co-tranferred to Enterococcus faecalis. Finally the nature of the genetic support for one of the tet(W) genes, was determined and found to be flanked by two transposases belonging to two different families of insertion sequences (IS30 and IS256). This element was highly unstable in E. coli. This study showed that antibiotic-resistant bacteria and antibiotic resistance genes are present in the oral microbiota and that oral bacteria are likely to play an important role in the evolution and dissemination of antibiotic resistance genes.
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Moss, Stephen James. « Cloning and expression of the genes encoding the chick muscle nicotinic acetylcholine receptor ». Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47576.
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Bian, Zhuyun. « Characterization of Effector Encoding Genes from the Novel Sugar Beet Pathogen Fusarium Secorum ». Thesis, North Dakota State University, 2015. https://hdl.handle.net/10365/27711.
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A new disease of sugar beet, named Fusarium yellowing decline, was recently found in in the Red River Valley of MN and ND. This disease is caused by a novel pathogen named Fusarium secorum. Pathogens such as F. secorum secrete proteins during infection called ?effectors? that help establish disease. Since pathogenicity and disease development may depend on effector proteins produced by F. secorum during infection, effector protein identification furthers our understanding of the biology of this important pathogen. A list of 11 candidate effectors was generated previously. In this study, to characterize putative effectors, we developed a transformation system using polyethylene glycol?mediated transformation. Several mutant lines were created with an effector deleted from the genome using a split-marker knock-out strategy. To explore their role in pathogenicity, mutant strains have been inoculated to sugarbeet and compared to WT F. secorum.
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Berger, David Kenneth. « Studies on genes encoding regulators of nitrogen metabolism in Thiobacillus ferrooxidans ATCC 33020 ». Thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/26110.
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Ni, Ying. « Genes Encoding Succinate Dehydrogenase as Susceptibility Factors in Cowden and Cowden-Like Syndrome ». Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1341497587.
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Raymond, Rhonda Kay. « Isolation and characterization of two genes encoding methylenetetrahydrofolate reductase isozymes from Saccharomyces cerevisiae / ». Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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