Chitin synthesis in the salmon louse Lepeophtheirus salmonis
The salmon louse Lepeophtheirus salmonis is a parasitic copepod that lives and feeds on Atlantic salmon (Salmo salmar). At present, this parasite is the number one threat to the Norwegian aquaculture. The density of salmons living together in aquaculture sea cages gives the salmon lice optimal condi...
Published in: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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The University of Bergen
2021
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Online Access: | https://hdl.handle.net/11250/2759154 |
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ftunivbergen:oai:bora.uib.no:11250/2759154 2023-05-15T15:32:54+02:00 Chitin synthesis in the salmon louse Lepeophtheirus salmonis Hardardottir, Hulda Maria 2021-06-07T07:51:44.433Z application/pdf https://hdl.handle.net/11250/2759154 eng eng The University of Bergen Paper I: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, Christiane Eichner, Michael Dondrup, and Sussie Dalvin (2019): Chitin synthesis and degradation in Lepeophtheirus salmonis: Molecular characterization and gene expression profile during synthesis of a new exoskeleton. Comparative Biochemistry and Physiology, Part A, 227, 123-133. The article is available in the thesis file. The article is also available at: https://doi.org/10.1016/j.cbpa.2018.10.008 Paper II: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, and Sussie Dalvin (2019): Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae. PLoS ONE 14(9): e0222520. The article is available at: http://hdl.handle.net/1956/21032 Paper III: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, and Sussie Dalvin (2021): Chitin synthases are critical for reproduction, molting, and digestion in the salmon louse (Lepeophtheirus salmonis). Life 11: 47. The article is available at: https://hdl.handle.net/11250/2759150 container/07/1b/48/47/071b4847-58a7-4a88-bdac-a20141748edd urn:isbn:9788230850787 urn:isbn:9788230840214 https://hdl.handle.net/11250/2759154 In copyright http://rightsstatements.org/page/InC/1.0/ Copyright the Author. All rights reserved Doctoral thesis 2021 ftunivbergen https://doi.org/10.1016/j.cbpa.2018.10.008 2023-03-14T17:41:02Z The salmon louse Lepeophtheirus salmonis is a parasitic copepod that lives and feeds on Atlantic salmon (Salmo salmar). At present, this parasite is the number one threat to the Norwegian aquaculture. The density of salmons living together in aquaculture sea cages gives the salmon lice optimal conditions for infecting and reproducing. Many delousing methods, both non-chemical and chemical, are available for the treatments of salmon lice. In salmon aquaculture, four benzoylureas-derived chitin synthesis inhibitors (CSI) are used: Hexaflumuron, diflubenzuron, teflubenzuron, and lufenuron. In-feed treatments based on diflubenzuron or teflubenzuron are used by Norwegian farmers, while hexaflumuron- and lufenuron-based treatments are known to be available in Chile. Despite many options for treating lice, current treatments are not optimal because 1) resistance can develop, 2) there are environmental issues associated with chemical treatments, and 2) non-chemical treatments can inflict stress-related damage on the fish. Therefore, new treatments are needed. By investigating the molecular biology of L. salmonis, it is hoped that new candidates can be discovered. Salmon lice have a rigid exoskeleton around the body, which must be removed for future growth to occur. During the development, the salmon louse molt to get to the next life stage. Molt, or ecdysis, is an essential process in all arthropods, and the salmon louse molts eight times to reach the adult life stage. Chitin is one of the main components of the exoskeleton, and the chitin synthesis pathway is very conserved in chitin-synthesizing organisms. The key chitin synthesis transcripts (LsGFAT, LsGNA1, LsAGM, LsUAP, and LsCHS1/2) were cloned and their sequences were analyzed to understand chitin synthesis in L. salmonis better. The results showed that L. salmonis has enzymes similar to other arthropods and these are most similar to other crustaceans' sequences, especially other copepods. The expression patterns of these chitin synthesis genes and chitinases ... Doctoral or Postdoctoral Thesis Atlantic salmon Copepods University of Bergen: Bergen Open Research Archive (BORA-UiB) Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 227 123 133 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
The salmon louse Lepeophtheirus salmonis is a parasitic copepod that lives and feeds on Atlantic salmon (Salmo salmar). At present, this parasite is the number one threat to the Norwegian aquaculture. The density of salmons living together in aquaculture sea cages gives the salmon lice optimal conditions for infecting and reproducing. Many delousing methods, both non-chemical and chemical, are available for the treatments of salmon lice. In salmon aquaculture, four benzoylureas-derived chitin synthesis inhibitors (CSI) are used: Hexaflumuron, diflubenzuron, teflubenzuron, and lufenuron. In-feed treatments based on diflubenzuron or teflubenzuron are used by Norwegian farmers, while hexaflumuron- and lufenuron-based treatments are known to be available in Chile. Despite many options for treating lice, current treatments are not optimal because 1) resistance can develop, 2) there are environmental issues associated with chemical treatments, and 2) non-chemical treatments can inflict stress-related damage on the fish. Therefore, new treatments are needed. By investigating the molecular biology of L. salmonis, it is hoped that new candidates can be discovered. Salmon lice have a rigid exoskeleton around the body, which must be removed for future growth to occur. During the development, the salmon louse molt to get to the next life stage. Molt, or ecdysis, is an essential process in all arthropods, and the salmon louse molts eight times to reach the adult life stage. Chitin is one of the main components of the exoskeleton, and the chitin synthesis pathway is very conserved in chitin-synthesizing organisms. The key chitin synthesis transcripts (LsGFAT, LsGNA1, LsAGM, LsUAP, and LsCHS1/2) were cloned and their sequences were analyzed to understand chitin synthesis in L. salmonis better. The results showed that L. salmonis has enzymes similar to other arthropods and these are most similar to other crustaceans' sequences, especially other copepods. The expression patterns of these chitin synthesis genes and chitinases ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Hardardottir, Hulda Maria |
spellingShingle |
Hardardottir, Hulda Maria Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
author_facet |
Hardardottir, Hulda Maria |
author_sort |
Hardardottir, Hulda Maria |
title |
Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
title_short |
Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
title_full |
Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
title_fullStr |
Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
title_full_unstemmed |
Chitin synthesis in the salmon louse Lepeophtheirus salmonis |
title_sort |
chitin synthesis in the salmon louse lepeophtheirus salmonis |
publisher |
The University of Bergen |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2759154 |
genre |
Atlantic salmon Copepods |
genre_facet |
Atlantic salmon Copepods |
op_relation |
Paper I: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, Christiane Eichner, Michael Dondrup, and Sussie Dalvin (2019): Chitin synthesis and degradation in Lepeophtheirus salmonis: Molecular characterization and gene expression profile during synthesis of a new exoskeleton. Comparative Biochemistry and Physiology, Part A, 227, 123-133. The article is available in the thesis file. The article is also available at: https://doi.org/10.1016/j.cbpa.2018.10.008 Paper II: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, and Sussie Dalvin (2019): Effects of chitin synthesis inhibitor treatment on Lepeophtheirus salmonis (Copepoda, Caligidae) larvae. PLoS ONE 14(9): e0222520. The article is available at: http://hdl.handle.net/1956/21032 Paper III: Hulda Maria Hardardottir, Rune Male, Frank Nilsen, and Sussie Dalvin (2021): Chitin synthases are critical for reproduction, molting, and digestion in the salmon louse (Lepeophtheirus salmonis). Life 11: 47. The article is available at: https://hdl.handle.net/11250/2759150 container/07/1b/48/47/071b4847-58a7-4a88-bdac-a20141748edd urn:isbn:9788230850787 urn:isbn:9788230840214 https://hdl.handle.net/11250/2759154 |
op_rights |
In copyright http://rightsstatements.org/page/InC/1.0/ Copyright the Author. All rights reserved |
op_doi |
https://doi.org/10.1016/j.cbpa.2018.10.008 |
container_title |
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
container_volume |
227 |
container_start_page |
123 |
op_container_end_page |
133 |
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1766363374110638080 |