Expression of growth hormone genes in Atlantic salmon

1993 ◽  
Vol 11 (2) ◽  
pp. 167-179 ◽  
Author(s):  
J B Lorens ◽  
A H Nerland ◽  
R Aasland ◽  
I Lossius ◽  
R Male
Keyword(s):  
Atlantic Salmon ◽  
Transcriptional Start Site ◽  
Northern Analysis ◽  
Rnase Protection ◽  
Reverse Transcription Pcr ◽  
Transcript Length ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
Pcr Assays

ABSTRACT Atlantic salmon (Salmo salar) possess two genes encoding GH. We have investigated the expression of these two genes in the salmon pituitary. The transcriptional start site was localized 64 nucleotides upstream of the first methionyl codon using primer extension and 5′ specific polymerase chain reaction (PCR) assays. Northern analysis revealed a major Atlantic salmon GH (salGH) transcript band of approximately 1400 nucleotides. As coexpression of the salGH genes is not discernible by transcript length, other techniques were used to assess gene activity; RNase protection analysis revealed GH transcript heterogeneity, while reverse transcription-PCR assays detected transcripts from both genes at approximately equivalent amounts. The encoded salGH protein, generated in vitro and by Escherichia coli, shares electrophoretic and immunoreactive identity with native pituitary salGH.

scholarly journals The Yeast Signal Sequence Trap Identifies Secreted Proteins of the Hemibiotrophic Corn Pathogen Colletotrichum graminicola

2008 ◽  
Vol 21 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Jorrit-Jan Krijger ◽  
Ralf Horbach ◽  
Michael Behr ◽  
Patrick Schweizer ◽  
Holger B. Deising ◽  
...  
Keyword(s):  
Cell Walls ◽  
Leaf Extract ◽  
Signal Sequence ◽  
Stem Rot ◽  
Colletotrichum Graminicola ◽  
In Planta ◽  
Chain Reaction ◽  
Genes Encoding ◽  
Polymerase Chain

The hemibiotroph Colletotrichum graminicola is the causal agent of stem rot and leaf anthracnose on Zea mays. Following penetration of epidermal cells, the fungus enters a short biotrophic phase, followed by a destructive necrotrophic phase of pathogenesis. During both phases, secreted fungal proteins are supposed to determine progress and success of the infection. To identify genes encoding such proteins, we constructed a yeast signal sequence trap (YSST) cDNA-library from RNA extracted from mycelium grown in vitro on corn cell walls and leaf extract. Of the 103 identified unigenes, 50 showed significant similarities to genes with a reported function, 25 sequences were similar to genes without a known function, and 28 sequences showed no similarity to entries in the databases. Macroarray hybridization and quantitative reverse-transcriptase polymerase chain reaction confirmed that most genes identified by the YSST screen are expressed in planta. Other than some genes that were constantly expressed, a larger set showed peaks of transcript abundances at specific phases of pathogenesis. Another set exhibited biphasic expression with peaks at the biotrophic and necrotrophic phase. Transcript analyses of in vitro-grown cultures revealed that several of the genes identified by the YSST screen were induced by the addition of corn leaf components, indicating that host-derived factors may have mimicked the host milieu.

scholarly journals Involvement of the C-Terminal Extension of the α Polypeptide and of the PucC Protein in LH2 Complex Biosynthesis in Rubrivivax gelatinosus

2004 ◽  
Vol 186 (10) ◽  
pp. 3143-3152 ◽  
Author(s):  
Anne-Soisig Steunou ◽  
Soufian Ouchane ◽  
Françoise Reiss-Husson ◽  
Chantal Astier
Keyword(s):  
Purple Bacteria ◽  
Growth Conditions ◽  
Initiation Site ◽  
Northern Blotting ◽  
Pcr Analysis ◽  
Reverse Transcription Pcr ◽  
Genes Encoding ◽  
Rubrivivax Gelatinosus

ABSTRACT The facultative phototrophic nonsulfur bacterium Rubrivivax gelatinosus exhibits several differences from other species of purple bacteria in the organization of its photosynthetic genes. In particular, the puc operon contains only the pucB and pucA genes encoding the β and α polypeptides of the light-harvesting 2 (LH2) complex. Downstream of the pucBA operon is the pucC gene in the opposite transcriptional orientation. The transcription of pucBA and pucC has been studied. No pucC transcript was detected either by Northern blotting or by reverse transcription-PCR analysis. The initiation site of pucBA transcription was determined by primer extension, and Northern blot analysis revealed the presence of two transcripts of 0.8 and 0.65 kb. The half-lives of both transcripts are longer in cells grown semiaerobically than in photosynthetically grown cells, and the small transcript is the less stable. It was reported that the α polypeptide, encoded by the pucA gene, presents a C-terminal extension which is not essential for LH2 function in vitro. The biological role of this alanine- and proline-rich C-terminal extension in vivo has been investigated. Two mutants with C-terminal deletions of 13 and 18 residues have been constructed. Both present the two pucBA transcripts, while their phenotypes are, respectively, LH2+ and LH2−, suggesting that a minimal length of the C-terminal extension is required for LH2 biogenesis. Another important factor involved in the LH2 biogenesis is the PucC protein. To gain insight into the function of this protein in R. gelatinosus, we constructed and characterized a PucC mutant. The mutant is devoid of LH2 complex under semiaerobiosis but still produces a small amount of these antennae under photosynthetic growth conditions. This conditional phenotype suggests the involvement of another factor in LH2 biogenesis.

scholarly journals Ribonucleotide Reduction in Mycobacterium tuberculosis: Function and Expression of Genes Encoding Class Ib and Class II Ribonucleotide Reductases

2003 ◽  
Vol 71 (11) ◽  
pp. 6124-6131 ◽  
Author(s):  
Stephanie S. Dawes ◽  
Digby F. Warner ◽  
Liana Tsenova ◽  
Juliano Timm ◽  
John D. McKinney ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Class Ii ◽  
Growth Conditions ◽  
Small Subunit ◽  
Reverse Transcription Pcr ◽  
Hypoxic Conditions ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Class Ib

ABSTRACT Mycobacterium tuberculosis, the causative agent of tuberculosis, possesses a class Ib ribonucleotide reductase (RNR), encoded by the nrdE and nrdF2 genes, in addition to a putative class II RNR, encoded by nrdZ. In this study we probed the relative contributions of these RNRs to the growth and persistence of M. tuberculosis. We found that targeted knockout of the nrdF2 gene could be achieved only in the presence of a complementing allele, confirming that this gene is essential under normal, in vitro growth conditions. This observation also implied that the alternate class Ib small subunit encoded by the nrdF1 gene is unable to substitute for nrdF2 and that the class II RNR, NrdZ, cannot substitute for the class Ib enzyme, NrdEF2. Conversely, a ΔnrdZ null mutant of M. tuberculosis was readily obtained by allelic exchange mutagenesis. Quantification of levels of nrdE, nrdF2, nrdF1, and nrdZ gene expression by real-time, quantitative reverse transcription-PCR with molecular beacons by using mRNA from aerobic and O2-limited cultures showed that nrdZ was significantly induced under microaerophilic conditions, in contrast to the other genes, whose expression was reduced by O2 restriction. However, survival of the ΔnrdZ mutant strain was not impaired under hypoxic conditions in vitro. Moreover, the lungs of B6D2/F1 mice infected with the ΔnrdZ mutant had bacterial loads comparable to those of lungs infected with the parental wild-type strain, which argues against the hypothesis that nrdZ plays a significant role in the virulence of M. tuberculosis in this mouse model.

scholarly journals The tra Region of the Conjugative Plasmid pIP501 Is Organized in an Operon with the First Gene Encoding the Relaxase

2002 ◽  
Vol 184 (6) ◽  
pp. 1801-1805 ◽  
Author(s):  
Brigitta Kurenbach ◽  
Dagmar Grothe ◽  
María Eugenia Farías ◽  
Ulrich Szewzyk ◽  
Elisabeth Grohmann
Keyword(s):  
Amino Acids ◽  
Transcriptional Start Site ◽  
Conjugative Plasmid ◽  
Start Codon ◽  
Start Site ◽  
Gene Encoding ◽  
Cleavage Activity ◽  
Reverse Transcription Pcr ◽  
Single Operon

ABSTRACT The tra genes orf1 to orf11 of pIP501 were shown to be transcribed as a single operon of 11.3 kb in Enterococcus faecalis by reverse transcription-PCR. The transcriptional start site of the tra mRNA was mapped at 110 bp upstream from the predicted TTG start codon of the first gene of the operon, the traA relaxase. The TraA protein (660 amino acids) and a C-terminally truncated version of the TraA protein (293 amino acids) were purified as fusions with glutathione S-transferase. oriT cleavage activity of both TraA proteins was demonstrated in vitro on supercoiled plasmid pVA2241 DNA containing oriTpIP501 . The activity of the DNA relaxase TraA is strictly dependent on the presence of Mg2+ or Mn2+ and is highest at temperatures of between 42 and 45°C.

scholarly journals Polymorphisms of TLR4: Rapid Genotyping and Reduced Response to Lipopolysaccharide of TLR4 Mutant Alleles

2002 ◽  
Vol 48 (10) ◽  
pp. 1661-1667 ◽  
Author(s):  
Christopher Schmitt ◽  
Andreas Humeny ◽  
Cord-Michael Becker ◽  
Kay Brune ◽  
Andreas Pahl
Keyword(s):  
Rflp Analysis ◽  
Blood Monocytes ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Reverse Transcription Pcr ◽  
Flight Mass Spectrometry ◽  
Pcr Assays ◽  
Factor Α ◽  
Tof Ms

Abstract Background: Pathogen recognition receptors such as Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns, lead to the activation of innate immunity. Genetic variations in these receptors may lead to an altered host immune response to pathogens. Methods: We developed homogeneous fluorescence-based PCR assays as well as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) genotyping assays to detect TLR4 polymorphisms. These assays were compared with restriction fragment length polymorphism (RFLP) analysis. Peripheral blood monocytes from donors with differing genotypes were prepared and exposed to bacterial products in vitro. The abundance of mRNAs of the proinflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-α from these monocytes were monitored by real-time reverse transcription-PCR. Results: By our homogeneous PCR method, the allele frequencies were 5.6% for the TLR4 Asp299Gly and 6.0% for the TLR4 Thr399Ile polymorphism in 116 healthy German Caucasians. Nine incorrect genotype calls were detected in the RFLP analysis and two in the TaqMan genotype analysis. MALDI-TOF-MS allowed clear detection of all TLR4 alleles. Monocytes from donors homozygous for the TLR4 mutant alleles Asp299Gly and Thr399Ile were lipopolysaccharide hyporesponsive and exhibited median effective concentrations (EC50s) approximately fourfold higher than those of monocytes carrying wild-type or heterozygous alleles. In contrast, a TLR2 agonist elicited similar responses in monocytes irrespective of the TLR4 genotype. Conclusions: Homogeneous fluorescence-based PCR assays provide a specific and sensitive method for high-throughput genotyping of TLR4 mutations. The newly developed PCR and MALDI-TOF-MS assays may be useful to evaluate the presence of TLR4 polymorphisms in patients to predict susceptibility to bacterial infection.

scholarly journals Detection and Typing of Human Pathogenic Hantaviruses by Real-Time Reverse Transcription-PCR and Pyrosequencing

2007 ◽  
Vol 53 (11) ◽  
pp. 1899-1905 ◽  
Author(s):  
Marit Kramski ◽  
Helga Meisel ◽  
Boris Klempa ◽  
Detlev H Krüger ◽  
Georg Pauli ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Hantaan Virus ◽  
Hantavirus Infection ◽  
Sequence Information ◽  
Rt Pcr ◽  
Clinical Specimens ◽  
Reverse Transcription Pcr ◽  
Pcr Assays

Abstract Background: Because the clinical course of human infections with hantaviruses can vary from subclinical to fatal, rapid and reliable detection of hantaviruses is essential. To date, the diagnosis of hantavirus infection is based mainly on serologic assays, and the detection of hantaviral RNA by the commonly used reverse transcription (RT)-PCR is difficult because of high sequence diversity of hantaviruses and low viral loads in clinical specimens. Methods: We developed 5 real-time RT-PCR assays, 3 of which are specific for the individual European hantaviruses Dobrava, Puumala, or Tula virus. Two additional assays detect the Asian species Hantaan virus together with Seoul virus and the American species Andes virus together with Sin Nombre virus. Pyrosequencing was established to provide characteristic sequence information of the amplified hantavirus for confirmation of the RT-PCR results or for a more detailed virus typing. Results: The real-time RT-PCR assays were specific for the respective hantavirus species and optimized to run on 2 different platforms, the LightCycler and the ABI 7900/7500. Each assay showed a detection limit of 10 copies of a plasmid containing the RT-PCR target region, and pyrosequencing was possible with 10 to 100 copies per reaction. With this assay, viral genome could be detected in 16 of 552 (2.5%) specimens of suspected hantavirus infections of humans and mice. Conclusions: The new assays detect, differentiate, and quantify hantaviruses in clinical specimens from humans and from their natural hosts and may be useful for in vitro studies of hantaviruses.

scholarly journals Role of Staphylococcus aureus Global Regulators sae and σB in Virulence Gene Expression during Device-Related Infection

2005 ◽  
Vol 73 (6) ◽  
pp. 3415-3421 ◽  
Author(s):  
Christiane Goerke ◽  
Ursula Fluckiger ◽  
Andrea Steinhuber ◽  
Vittoria Bisanzio ◽  
Martina Ulrich ◽  
...  
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Virulence Gene ◽  
Northern Analysis ◽  
Virulence Gene Expression ◽  
Global Regulators ◽  
Reverse Transcription Pcr ◽  
Direct Cross

ABSTRACT The ability of Staphylococcus aureus to adapt to different environments is due to a regulatory network comprising several loci. Here we present a detailed study of the interaction between the two global regulators sae and σB of S. aureus and their influence on virulence gene expression in vitro, as well as during device-related infection. The expression of sae, asp23, hla, clfA, coa, and fnbA was determined in strain Newman and its isogenic saeS/R and sigB mutants by Northern analysis and LightCycler reverse transcription-PCR. There was no indication of direct cross talk between the two regulators. sae had a dominant effect on target gene expression during device-related infection. σB seemed to be less active throughout the infection than under induced conditions in vitro.

scholarly journals Effects of Subinhibitory Concentrations of Antibiotics on Colonization Factor Expression by Moxifloxacin-Susceptible and Moxifloxacin-Resistant Clostridium difficile Strains

2009 ◽  
Vol 53 (12) ◽  
pp. 5155-5162 ◽  
Author(s):  
Cécile Denève ◽  
Sylvie Bouttier ◽  
Bruno Dupuy ◽  
Frédéric Barbut ◽  
Anne Collignon ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Fluoroquinolone Resistance ◽  
Reverse Transcription Pcr ◽  
Colonization Factor ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Subinhibitory Concentrations ◽  
The Impact

ABSTRACT Recent outbreaks of Clostridium difficile infection have been related to the emergence of the NAP1/027 epidemic strain. This strain demonstrates increased virulence and resistance to the C-8-methoxyfluoroquinolones gatifloxacin and moxifloxacin. These antibiotics have been implicated as major C. difficile infection-inducing agents. We investigated by real-time reverse transcription-PCR the impact of subinhibitory concentrations of ampicillin, clindamycin, ofloxacin, and moxifloxacin on the expression of genes encoding three colonization factors, the protease Cwp84, the high-molecular-weight S-layer protein, and the fibronectin-binding protein Fbp68. We have previously shown in six non-NAP1/027 moxifloxacin-susceptible strains that the presence of ampicillin or clindamycin induced an upregulation of these genes, whereas the presence of fluoroquinolones did not. The objective of this study was to analyze the expression of these genes under the same conditions in four NAP1/027 strains, one moxifloxacin susceptible and three moxifloxacin resistant. Two in vitro-selected moxifloxacin-resistant mutants were also analyzed. Moxifloxacin resistance was associated with the Thr82→Ile substitution in GyrA in all but one of the moxifloxacin-resistant strains. The expression of cwp84 and slpA was strongly increased after culture with ampicillin or clindamycin in NAP1/027 strains. Interestingly, after culture with fluoroquinolones, the expression of cwp84 and slpA was only increased in four moxifloxacin-resistant strains, including the NAP1/027 strains and one of the in vitro-selected mutants. The overexpression of cwp84 was correlated with increased production of the protease Cwp84. The historical NAP1/027 moxifloxacin-susceptible strain and its mutant appear to be differently regulated by fluoroquinolones. Overall, fluoroquinolones appear to favor the expression of some colonization factor-encoding genes in resistant C. difficile strains. The fluoroquinolone resistance of the NAP1/027 epidemic strains could be considered an ecological advantage. This could also increase their colonization fitness and promote the infection.

scholarly journals In vitro activity of ceftazidime/avibactam against isolates of carbapenem-non-susceptible Enterobacteriaceae collected during the INFORM global surveillance programme (2015–17)

2019 ◽  
Vol 75 (2) ◽  
pp. 384-391 ◽  
Author(s):  
Iris Spiliopoulou ◽  
Krystyna Kazmierczak ◽  
Gregory G Stone
Keyword(s):  
Antimicrobial Activity ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
Gene Encoding ◽  
Surveillance Programme ◽  
Genes Encoding ◽  
The Usa ◽  
Report Data ◽  
Pcr Assays

Abstract Objectives To report data for ceftazidime/avibactam and comparators against meropenem-non-susceptible Enterobacteriaceae collected globally (excluding centres in the USA) from 2015 to 2017 as part of the International Network For Optimal Resistance Monitoring (INFORM) surveillance programme. Methods MICs and susceptibility were determined using EUCAST broth microdilution methodology and EUCAST breakpoints. Isolates were screened to detect genes encoding β-lactamases using multiplex PCR assays. MBL-positive isolates were those in which one or more of the IMP, VIM and/or NDM genes were detected. Results A total of 1460 meropenem-non-susceptible isolates were collected and, of the agents on the panel, susceptibility was highest to ceftazidime/avibactam, colistin and tigecycline [73.0%, 77.0% (1081/1403) and 78.1%, respectively]. Ceftazidime/avibactam was not active against MBL-positive isolates (n=367); these isolates showed the highest rates of susceptibility to colistin (92.1%, 303/329), tigecycline (71.9%) and amikacin (46.6%). A total of 394 isolates were resistant to ceftazidime/avibactam and, of the 369 isolates that were screened, 98.4% were found to carry a gene encoding an MBL enzyme. Among isolates that were identified as carbapenemase positive and MBL negative (n=910), susceptibility was highest to ceftazidime/avibactam (99.8%). Susceptibility was also highest to ceftazidime/avibactam among isolates that were carbapenemase negative and MBL negative (94/98, 95.9%). Conclusions These data highlight the need for continued surveillance of antimicrobial activity as well as the need for new antimicrobials to treat infections caused by meropenem-non-susceptible Enterobacteriaceae, for which the options are extremely limited.

scholarly journals Characterization of the Rhesus Cytomegalovirus US28 Locus

2003 ◽  
Vol 77 (19) ◽  
pp. 10404-10413 ◽  
Author(s):  
M. E. T. Penfold ◽  
T. L. Schmidt ◽  
D. J. Dairaghi ◽  
P. A. Barry ◽  
T. J. Schall
Keyword(s):  
Viral Entry ◽  
Intracellular Signaling ◽  
Northern Analysis ◽  
Reading Frame ◽  
Reverse Transcription Pcr ◽  
Wide Range ◽  
Infected Cells ◽  
G Protein Coupled

ABSTRACT Human cytomegalovirus (CMV) US28 (and the related open reading frame [ORF] US27) are G-protein-coupled receptor homologs believed to play a role in viral pathogenesis. In vitro, US28 has been shown to bind and internalize ligands, as well as activate intracellular signaling in response to certain chemokines, and to initiate the migration of smooth muscle cells to chemokine gradients. To assess the role of US28 in vivo, we examined the rhesus model and sequenced and characterized the rhesus CMV US28 locus. We found that rhesus CMV carries five tandem homologs of US28, all widely divergent from US28 and from each other. By reverse transcription-PCR and Northern analysis, we demonstrated expression of these ORFs in infected cells. With stable cell lines expressing these ORFs, we analyzed the homolog's binding and signaling characteristics across a wide range of chemokines and found one (RhUS28.5) to have a ligand binding profile similar to that of US28. In addition, we localized US28 and the rhesus CMV homolog RhUS28.5 to the envelope of infectious virions, suggesting a role in viral entry or cell tropism.

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