Blar i Department of Biological Sciences på forfatter "Nilsen, Frank"
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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 ... -
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 ... -
Genomic Resources for Sea Lice: Analysis of ESTs and Mitochondrial Genomes
Yasuike, Motoshige; Leong, Jong; Jantzen, Stuart G.; Schalburg, Kristian R. von; Nilsen, Frank; Jones, Simon R. M.; Koop, Ben F. (Peer reviewed; Journal article, 2011-07-12)Sea lice are common parasites of both farmed and wild salmon. Salmon farming constitutes an important economic market in North America, South America, and Northern Europe. Infections with sea lice can result in significant ... -
Growth reaction norms of domesticated, wild and hybrid Atlantic salmon families in response to differing social and physical environments
Solberg, Monica Favnebøe; Zhang, Zhiwei; Nilsen, Frank; Glover, Kevin (Peer reviewed; Journal article, 2013-10-28)Background: Directional selection for growth has resulted in the 9-10th generation of domesticated Atlantic salmon Salmo salar L. outgrowing wild salmon by a ratio of approximately 3:1 when reared under standard hatchery ... -
Hatching time and alevin growth prior to the onset of exogenous feeding in farmed, wild and hybrid Norwegian Atlantic salmon
Solberg, Monica Favnebøe; Fjelldal, Per Gunnar; Nilsen, Frank; Glover, Kevin (Peer reviewed; Journal article, 2014-12-01)The onset of exogenous feeding, when juveniles emerge from the gravel, is a critical event for salmonids where early emergence and large size provide a competitive advantage in the wild. Studying 131 farmed, hybrid and ... -
Heavy and light chain homologs of ferritin are essential for blood-feeding and egg production of the ectoparasitic copepod Lepeophtheirus salmonis
Heggland, Erna Irene; Trösse, Christiane; Eichner, Christiane; Nilsen, Frank (Peer reviewed; Journal article, 2019)The salmon louse, Lepeophtheirus salmonis, is a hematophagous ectoparasite of salmonid fish. Due to its blood-feeding activity, the louse is exposed to great amounts of iron, which is an essential, yet potentially toxic ... -
Host gill attachment causes blood-feeding by the salmon louse (Lepeophtheirus salmonis) chalimus larvae and alters parasite development and transcriptome
Heggland, Erna Irene; Dondrup, Michael; Nilsen, Frank; Eichner, Christiane (Journal article; Peer reviewed, 2020-05-06)Background: Blood-feeding is a common strategy among parasitizing arthropods, including the ectoparasitic salmon louse (Lepeophtheirus salmonis), feeding off its salmon host’s skin and blood. Blood is rich in nutrients, ... -
Human-induced evolution caught in action: SNP-array reveals rapid amphi-atlantic spread of pesticide resistance in the salmon ecotoparasite Lepeophtheirus salmonis
Besnier, Francois; Kent, Matthew; Skern-Mauritzen, Rasmus; Lien, Sigbjørn; Malde, Ketil; Edvardsen, Rolf; Taylor, Simon; Ljungfeldt, Lina; Nilsen, Frank; Glover, Kevin (Peer reviewed; Journal article, 2014-10-26)Background: The salmon louse, Lepeophtheirus salmonis, is an ectoparasite of salmonids that causes huge economic losses in salmon farming, and has also been causatively linked with declines of wild salmonid populations. ... -
Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection
Moen, Thomas; Hayes, Ben; Nilsen, Frank; Delghandi, Madjid; Fjalestad, Kjersti T.; Fevolden, Svein-Erik; Berg, Paul R.; Lien, Sigbjørn (Peer reviewed; Journal article, 2008-02-26)Background The Atlantic cod (Gadus morhua) is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable ...