Blar i forfatter Artikler, rapporter og annet (kjemi) "Haugen, Peik"

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    • Bipartite Genomes in Enterobacterales: Independent Origins of Chromids, Elevated Openness and Donors of Horizontally Transferred Genes 

      Sonnenberg, Cecilie Bækkedal; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-21)
      Multipartite bacteria have one chromosome and one or more chromid. Chromids are believed to have properties that enhance genomic flexibility, making them a favored integration site for new genes. However, the mechanism by which chromosomes and chromids jointly contribute to this flexibility is not clear. To shed light on this, we analyzed the openness of chromosomes and chromids of the two bacteria, ...

    • Closely-related Photobacterium strains comprise the majority of bacteria in the gut of migrating Atlantic cod (Gadus morhua) 

      Le Doujet, Typhaine; De Santi, Concetta; Klemetsen, Terje; Hjerde, Erik; Willassen, Nils Peder; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-17)
      <p><i>Background - </i>The population of Atlantic cod (<i>Gadus morhua</i>), also known as Northeast Arctic cod, migrating Atlantic cod, or simply “skrei,” lives mainly in the Barents Sea and Svalbard waters and migrates in annual cycles to the Norwegian coast in order to spawn eggs during late winter. It is the world’s largest population of Atlantic cod, and the population is distinct from the ...

    • Complete Genome Sequences of Seven Vibrio anguillarum Strains as Derived from PacBio Sequencing 

      Holm, Kåre Olav; Bækkedal, Cecilie; Johansson Söderberg, Jenny; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-07)
      We report here the complete genome sequences of seven Vibrio anguillarum strains isolated from multiple geographic locations, thus increasing the total number of genomes of finished quality to 11. The genomes were de novo assembled from long-sequence PacBio reads. Including draft genomes, a total of 44 V. anguillarum genomes are currently available in the genome databases. They represent an important ...

    • Distribution of siderophore gene systems on a Vibrionaceae phylogeny: Database searches, phylogenetic analyses and evolutionary perspectives 

      Thode, Sunniva Katharina; Rojek, Ewelina; Kozlowski, Mikolaj; Ahmad, Rafi; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-14)
      Siderophores are small molecules synthesized and secreted by bacteria and fungi to scavenge iron. Extracellular ferri-siderohores are recognized by cognate receptors on the cell surface for transport over membranes. Several siderophore systems from <i>Vibrionaceae</i> representatives are known and well understood, e.g., the molecular structure of the siderophore, the biosynthesis gene cluster ...

    • Expression profiling reveals Spot 42 small RNA as a key regulator in the central metabolism of Aliivibrio salmonicida 

      Hansen, Geir Åsmund; Ahmad, Rafi; Hjerde, erik; Fenton, Christopher Graham; Willassen, Nils Peder; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Spot 42 was discovered in Escherichia coli nearly 40 years ago as an abundant, small and unstable RNA. Its biological role has remained obscure until recently, and is today implicated in having broader roles in the central and secondary metabolism. Spot 42 is encoded by the spf gene. The gene is ubiquitous in the Vibrionaceae family of gamma-proteobacteria. One member of this family, Aliivibrio ...

    • The immediate global responses of Aliivibrio salmonicida to iron limitations 

      Thode, Sunniva Katharina; Kahlke, Tim; Robertsen, Espen Mikal; Hansen, Hilde; Haugen, Peik (Journal article; Tidsskriftartikkel, 2015-02-04)
      <i>Background</i>: Iron is an essential micronutrient for all living organisms, and virulence and sequestration of iron in pathogenic bacteria are believed to be correlated. As a defence mechanism, potential hosts therefore keep the level of free iron inside the body to a minimum. In general, iron metabolism is well studied for some bacteria (mostly human or animal pathogens). However, this area ...

    • Mobile group I introns at nuclear rDNA position L2066 harbor sense and antisense homing endonuclease genes intervened by spliceosomal introns 

      Lian, Kjersti; Furulund, Betty Martine Normann; Tveita, Anders Aune; Haugen, Peik; Johansen, Steinar Daae (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-08)
      Background: Mobile group I introns encode homing endonucleases that confer intron mobility initiated by a double-strand break in the intron-lacking allele at the site of insertion. Nuclear ribosomal DNA of some fungi and protists contain mobile group I introns harboring His-Cys homing endonuclease genes (HEGs). An intriguing question is how protein-coding genes embedded in nuclear ribosomal DNA ...

    • Presence of acyl-homoserine lactones in 57 members of the Vibrionaceae family 

      Purohit, Amit Anand; Johansen, Jostein a; Hansen, Hilde; Leiros, Hanna-Kirsti S.; Kashulin, Alexander; Karlsen, Christian; Smalås, Arne O.; Haugen, Peik; Willassen, Nils Peder (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-05-31)
      Aims: The aim of this study was to use a sensitive method to screen and quantify 57 Vibrionaceae strains for the production of acyl-homoserine lactones (AHLs) and map the resulting AHL profiles onto a host phylogeny.<p> <p>Methods and Results: We used a high-performance liquid chromatography– tandem mass spectrometry (HPLC-MS/MS) protocol to measure AHLs in spent media after bacterial growth. ...

    • The Pseudoalteromonas multipartite genome: distribution and expression of pangene categories, and a hypothesis for the origin and evolution of the chromid 

      Sonnenberg, Cecilie Bækkedal; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-21)
      Bacterial genomes typically consist of one large chromosome, but can also include secondary replicons. These so-called multipartite genomes are scattered on the bacterial tree of life with the majority of cases belonging to Proteobacteria. Within the class gamma-proteobacteria, multipartite genomes are restricted to the two families <i>Vibrionaceae</i> and <i>Pseudoalteromonadaceae</i>. Whereas the ...

    • The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism 

      Haugen, Peik; Bækkedal, Cecilie (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-01)
      The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, ...

    • Structural Organization of S516 Group I Introns in Myxomycetes 

      Furulund, Betty Martine Normann; Karlsen, Bård Ove; Babiak, Igor; Haugen, Peik; Johansen, Steinar Daae (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-25)
      Group I introns are mobile genetic elements encoding self-splicing ribozymes. Group I introns in nuclear genes are restricted to ribosomal DNA of eukaryotic microorganisms. For example, the myxomycetes, which represent a distinct protist phylum with a unique life strategy, are rich in nucleolar group I introns. We analyzed and compared 75 group I introns at position 516 in the small subunit ...

    • Unique core genomes of the bacterial family vibrionaceae: insights into niche adaptation and speciation 

      Kahlke, Tim; Goesmann, Alexander; Hjerde, Erik; Willassen, Nils Peder; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      The criteria for defining bacterial species and even the concept of bacterial species itself are under debate, and the discussion is apparently intensifying as more genome sequence data is becoming available. However, it is still unclear how the new advances in genomics should be used most efficiently to address this question. In this study we identify genes that are common to any group of genomes ...

    • Vibrionaceae core, shell and cloud genes are non-randomly distributed on Chr 1: An hypothesis that links the genomic location of genes with their intracellular placement 

      Sonnenberg, Cecilie Bækkedal; Kahlke, Tim; Haugen, Peik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-06)
      <i>Background</i> - The genome of <i>Vibrionaceae</i> bacteria, which consists of two circular chromosomes, is replicated in a highly ordered fashion. In fast-growing bacteria, multifork replication results in higher gene copy numbers and increased expression of genes located close to the origin of replication of Chr 1 (<i>ori1</i>). This is believed to be a growth optimization strategy to satisfy ...