Browsing Bergen Open Research Archive by Author "Nilsen, Frank"
Now showing items 1-20 of 73
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Aquaculture-driven evolution of the salmon louse mtDNA genome
Rutle, Karoline Hasti; Skern-Mauritzen, Rasmus; Nilsen, Frank; Mateos-Rivera, Alejandro; Sørvik, Anne Grete Eide; Jansson, Eeva; Quintela, Maria; Besnier, Francois; Ayllon, Fernando; Fjørtoft, Helene Børretzen; Glover, Kevin Alan (Journal article; Peer reviewed, 2023)Resistance toward the antiparasitic pyrethroid, deltamethrin, is reported in the Atlantic salmon louse (Lepeophtheirus salmonis salmonis), a persistent ectoparasite of farmed and wild salmonids. The resistance mechanism ... -
Aquaculture-driven evolution: distribution of pyrethroid resistance in the salmon louse throughout the North Atlantic in the years 2000–2017
Fjørtoft, Helene Børretzen; Nilsen, Frank; Besnier, Francois; Espedal, Per Gunnar; Stene, Anne; Tveten, Ann-Kristin; Bjørn, Pål Arne; Aspehaug, Vidar; Glover, Kevin (Journal article; Peer reviewed, 2020)The parasitic salmon louse, and its documented resistance to chemotherapeutants, represents the most persistent environmental challenge to global salmonid aquaculture. We used a genetic marker associated with pyrethroid ... -
Atlantic Water Boundary Current Along the Southern Yermak Plateau, Arctic Ocean
Fer, Ilker; Peterson, Algot Kristoffer; Nilsen, Frank (Journal article; Peer reviewed, 2023)The major ocean current that carries heat into the Arctic Ocean splits into three main branches of Atlantic Water (AW) and recirculations when it encounters the Yermak Plateau (YP) located north of Svalbard. While the ... -
The Atlantic Water flow along the Vøring Plateau: Detecting frontal structures in oceanic station time series
Nilsen, Jan Even Øie; Nilsen, Frank (Journal article, 2007-01-13)The topographic steering of the baroclinic western branch of the Norwegian Atlantic Current (NwAC) determines the extent of Atlantic Water and location of the Arctic Front in the Nordic Seas. In this paper the geographical ... -
Atlantic water properties, transport and heat loss from mooring observations north of Svalbard
Koenig, Zoe Charlotte; Kalhagen, Kjersti; Kolås, Eivind Hugaas; Fer, Ilker; Nilsen, Frank; Cottier, Finlo (Journal article; Peer reviewed, 2022)The Atlantic Water inflow to the Arctic Ocean is transformed and modified in the area north of Svalbard, which influences the Arctic Ocean heat and salt budget. Year-round observations are relatively sparse in this region ... -
Baroclinic Instability in the West Spitsbergen Current
Teigen, Sigurd Henrik; Nilsen, Frank; Skogseth, Ragnheid; Gjevik, Bjørn; Beszczynska-Möller, Agnieszka (Peer reviewed; Journal article, 2011-07-15)Baroclinic instability in the West Spitsbergen Current is investigated, based on data from an array of current meter moorings along 78.83oN, across the deeper (1000-2400 m) section of the continental slope west of Svalbard. ... -
Barotropic instability in the West Spitsbergen Current
Teigen, Sigurd Henrik; Nilsen, Frank; Gjevik, Bjørn (Peer reviewed; Journal article, 2010-07-24)Barotropic instability in the shoreward branch of the West Spitsbergen Current is investigated on the basis of data from an array of current meter moorings along 78.83°N, across the upper continental slope and shelf break ... -
Calving rates at tidewater glaciers vary strongly with ocean temperature
Luckman, Adrian; Benn, Doug; Cottier, Finlo; Bevan, Suzanne; Nilsen, Frank; Inall, Mark (Peer reviewed; Journal article, 2015-10-09)Rates of ice mass loss at the calving margins of tidewater glaciers (frontal ablation rates) are a key uncertainty in sea level rise projections. Measurements are difficult because mass lost is replaced by ice flow at ... -
Characterization of a novel RXR receptor in the salmon louse (Lepeophtheirus salmonis, Copepoda) regulating growth and female reproduction
Eichner, Christiane; Dalvin, Sussie Trine; Skern-Mauritzen, Rasmus; Malde, Ketil; Kongshaug, Heidi; Nilsen, Frank (Peer reviewed; Journal article, 2015-02-14)Background: Nuclear receptors have crucial roles in all metazoan animals as regulators of gene transcription. A wide range of studies have elucidated molecular and biological significance of nuclear receptors but there are ... -
Characterization of three salmon louse (Lepeophtheirus salmonis) genes with fibronectin II domains expressed by tegumental type 1 glands
Harasimczuk, Ewa; Øvergård, Aina-Cathrine; Grotmol, Sindre; Nilsen, Frank; Dalvin, Sussie (Peer reviewed; Journal article, 2018-01)The salmon louse, Lepeophtheirus salmonis (Copepoda: Caligidae), is currently the most significant pathogen affecting the salmon farming industry in the Northern Hemisphere. Exocrine glands of blood-feeding parasites are ... -
Chitin synthases are critical for reproduction, molting, and digestion in the salmon louse (Lepeophtheirus salmonis)
Hardardottir, Hulda; Male, Rune; Nilsen, Frank; Dalvin, Sussie (Journal article; Peer reviewed, 2021-01-13)Chitin synthase (CHS) is a large transmembrane enzyme that polymerizes Uridine diphosphate N-acetylglucosamine into chitin. The genomes of insects often encode two chitin synthases, CHS1 and CHS2. Their functional roles ... -
Cloned and outbred Atlantic salmon display equal parasite dispersion when infected with the salmon louse
Glover, Kevin; Hansen, Tom Johnny; Besnier, Francois; Solberg, Monica Favnebøe; Fjelldal, Per Gunnar; Sørvik, Anne Grete Eide; Dalvin, Sussie; Nilsen, Frank (Peer reviewed; Journal article, 2017-11)The salmon louse is an ectoparasitic copepod that infects salmonids in the marine environment. This parasite causes a major economic and biological challenge to the Atlantic salmon farming industry, and efforts to increase ... -
A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis
Ljungfeldt, Lina; Espedal, Per Gunnar; Nilsen, Frank; Skern-Mauritzen, Mette; Glover, Kevin (Peer reviewed; Journal article, 2014-05-19)Background: The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing ... -
The ecdysone receptor (EcR) is a major regulator of tissue development and growth in the marine salmonid ectoparasite, Lepeophtheirus salmonis (Copepoda, Caligidae)
Sandlund, Liv; Nilsen, Frank; Male, Rune; Dalvin, Sussie (Peer reviewed; Journal article, 2016-08)The function of the ecdysone receptor (EcR) during development and molting has been thoroughly investigated in some arthropods such as insects but rarely in crustacean copepods such as the salmon louse Lepeophtheirus ... -
Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae
Hardardottir, Hulda; Male, Rune; Nilsen, Frank; Dalvin, Sussie (Peer reviewed; Journal article, 2019-09-23)The salmon louse (Lepeophtheirus salmonis) is an ectoparasite infecting Atlantic salmon (Salmo salar), which causes substantial problems to the salmon aquaculture and threatens wild salmon. Chitin synthesis inhibitors ... -
Effects of environmental stress on mRNA expression levels of seven genes related to oxidative stress and growth in Atlantic salmon Salmo salar L. of farmed, hybrid and wild origin
Solberg, Monica F.; Kvamme, Bjørn Olav; Nilsen, Frank; Glover, Kevin (Peer reviewed; Journal article, 2012-12-05)Background: Ten generations of domestication selection has caused farmed Atlantic salmon Salmo salar L. to deviate from wild salmon in a range of traits. Each year hundreds of thousands of farmed salmon escape into the ... -
Evaluation of photodegradable chitin synthetase inhibitors for the treatment of salmon lice (Lepeophtheirus salmonis)
Sydnes, Magne Olav; Eikemo, Vebjørn; Espedal, Per Gunnar; Sydnes, Leiv K.; Nilsen, Frank (Journal article; Peer reviewed, 2023)Some photolabile ethanolamine analogues of the chitin synthetase inhibitors diflubenzuron, teflubenzuron, and lufenuron were tested for activity as anti-lice compounds towards salmon lice (Lepeophtheirus salmonis). Two ... -
Gene expression analyses of immune responses in Atlantic salmon during early stages of infection by salmon louse (Lepeophtheirus salmonis) revealed bi-phasic responses coinciding with the copepod-chalimus transition
Tadiso, Tariku Markos; Krasnov, Aleksei; Skugor, Stanko; Afanasyev, Sergey; Hordvik, Ivar; Nilsen, Frank (Peer reviewed; Journal article, 2011-03-07)The salmon louse (Lepeophtheirus salmonis Krøyer), an ectoparasitic copepod with a complex life cycle causes significant losses in salmon aquaculture. Pesticide treatments against the parasite raise environmental concerns ... -
Gene expression in Atlantic salmon skin in response to infection with the parasitic copepod Lepeophtheirus salmonis, cortisol implant, and their combination
Krasnov, Aleksei; Skugor, Stanko; Todorcevic, Marijana; Glover, Kevin; Nilsen, Frank (Peer reviewed; Journal article, 2012-04-05)Background: The salmon louse is an ectoparasitic copepod that causes major economic losses in the aquaculture industry of Atlantic salmon. This host displays a high level of susceptibility to lice which can be accounted ... -
The genome sequence of Atlantic cod reveals a unique immune system
Star, Bastiaan; Nederbragt, Alexander Johan; Jentoft, Sissel; Grimholt, Unni; Malmstrøm, Martin; Gregers, Tone Fredsvik; Rounge, Trine Ballestad; Paulsen, Jonas; Solbakken, Monica Hongrø; Sharma, Animesh; Wetten, Ola Frang; Lanzén, Anders; Winer, Roger; Knight, James; Vogel, Jan-Hinnerk; Aken, Bronwen; Andersen, Øivind; Lagesen, Karin; Tooming-Klunderud, Ave; Edvardsen, Rolf; Kirubakaran, G. Tina; Espelund, Mari; Nepal, Chirag; Previti, A. Christopher; Karlsen, Bård Ove; Moum, Truls; Skage, Morten; Berg, Paul Ragnar; Gjøen, Tor; Kuhl, Heiner; Thorsen, Jim; Malde, Ketil; Reinhardt, Richard; Du, Lei; Johansen, Steinar Daae; Searle, Steve; Lien, Sigbjørn; Nilsen, Frank; Jonassen, Inge; Omholt, Stig W; Stenseth, Nils Christian; Jakobsen, Kjetill Sigurd (Peer reviewed; Journal article, 2011-09)Atlantic cod (Gadus morhua) is a large, cold-adapted teleost that sustains long-standing commercial fisheries and incipient aquaculture. Here we present the genome sequence of Atlantic cod, showing evidence for complex ...