I work at the Sea Lice Research centre with a focus on the host-parasite interaction of salmon louse (Lepeophtheirus salmonis) and Atlantic salmon as a host. We identify secretory proteins that are deposited from the lice onto the salmon to dampen immune responses.

Techniques that we use includes: transcriptomics, in situ bybridization, histology, SEM, functional studies with primary leucocytes and gene knock down (RNAi) etc

I teach in the aqua medicine program: Vertebrate zoology in BIO101 and histopathology (BIO275)

Academic article

• Patrick Alexander Nelson; Andreas Borchel; Aina-Cathrine Øvergård (2026). Increasing the immunogenicity of a salmon louse immune dampening protein for DNA vaccine application in Atlantic salmon. (external link)
• Aina-Cathrine Øvergård; Andreas Borchel; Christiane Eichner et al. (2025). The generalist Caligus elongatus is better at dampening the Atlantic salmon immune response than the salmonid specialist Lepeophtheirus salmonis. (external link)
• Angela Etayo; Håvard Bjørgen; Ivar Hordvik et al. (2024). Possible transport routes of IgM to the gut of teleost fish. (external link)
• Angela Etayo; Håvard Bjørgen; Erling Olaf Koppang et al. (2024). The ontogeny of lymphoid organs and IgM⁺ B-cells in ballan wrasse (Labrus bergylta) reveals a potential site for extrarenal B-cell lymphopoiesis: The pancreas. (external link)
• Helena Marie Doherty Midtbø; Christiane Eichner; Lars Are Hamre et al. (2024). Salmon louse labial gland enzymes: implications for host settlement and immune modulation. (external link)
• Helena Marie Doherty Midtbø; Andreas Borchel; Hugh Craig Morton et al. (2024). Cell death induced by Lepeophtheirus salmonis labial gland protein 3 in salmonid fish leukocytes: A mechanism for disabling host immune responses. (external link)
• Angela Etayo; Kai Kristoffer Lie; Reidun Marie Bjelland et al. (2023). The thymus and T-cell ontogeny in ballan wrasse (Labrus bergylta) is nutritionally modelled. (external link)
• Andreas Borchel; Christiane Eichner; Aina-Cathrine Øvergård (2023). Mining Lepeophtheirus salmonis RNA-Seq data for qPCR reference genes and their application in Caligus elongatus. (external link)
• Aina-Cathrine Øvergård; Christiane Eichner; Noelia Nuñez-Ortiz et al. (2023). Transcriptomic and targeted immune transcript analyses confirm localized skin immune responses in Atlantic salmon towards the salmon louse. (external link)
• Elisabeth Gislefoss; Amr Ahmed Abdelrahim Gamil; Aina-Cathrine Øvergård et al. (2023). Identification and characterization of two salmon louse heme peroxidases and their potential as vaccine antigens. (external link)
• Aina-Cathrine Øvergård; Helena Marie Doherty Midtbø; Lars Are Hamre et al. (2022). Small, charged proteins in salmon louse (Lepeophtheirus salmonis) secretions modulate Atlantic salmon (Salmo salar) immune responses and coagulation. (external link)
• Sussie Dalvin; Christiane Eichner; Michael Dondrup et al. (2021). Roles of three putative salmon louse (Lepeophtheirus salmonis) prostaglandin E2synthases in physiology and host–parasite interactions. (external link)
• Sussie Dalvin; Louise VG Jørgensen; Per W. Kania et al. (2020). Rainbow trout Oncorhynchus mykiss skin responses to salmon louse Lepeophtheirus salmonis: From copepodid to adult stage. (external link)
• Arnfinn Lodden Økland; Are Nylund; Aina-Cathrine Øvergård et al. (2019). Genomic characterization, phylogenetic position and in situ localization of a novel putative mononegavirus in Lepeophtheirus salmonis. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Sindre Grotmol et al. (2018). Salmon louse rhabdoviruses: Impact on louse development and transcription of selected Atlantic salmon immune genes.. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Heidi Kongshaug et al. (2017). RNAi-mediated treatment of two vertically transmitted rhabdovirus infecting the salmon louse (Lepeophtheirus salmonis).. (external link)
• Ewa Harasimczuk; Aina-Cathrine Øvergård; Sindre Grotmol et al. (2017). Characterization of three salmon louse (Lepeophtheirus salmonis) genes with fibronectin II domains expressed by tegumental type 1 glands. (external link)
• Aina-Cathrine Øvergård; Christiane Eichner; Frank Nilsen et al. (2017). Molecular characterization and functional analysis of a salmon louse (Lepeoptheirus salmonis, Krøyer 1838) heme peroxidase with a potential role in extracellular matrixes. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Ewa Harasimczuk et al. (2016). Exocrine glands of Lepeophtheirus salmonis (Copepoda: Caligidae): Distribution, developmental appearance, and site of secretion. (external link)
• Christiane Eichner; Aina-Cathrine Øvergård; Frank Nilsen et al. (2015). Molecular characterization and knock-down of salmon louse (Lepeophtheirus salmonis) prostaglandin E synthase. (external link)
• Arnfinn Lodden Økland; Are Nylund; Aina-Cathrine Øvergård et al. (2014). Genomic characterization and phylogenetic position of two new species in Rhabdoviridae infecting the parasitic copepod, salmon louse (Lepeophtheirus salmonis). (external link)
• Andreas L Steigen; Egil Karlsbakk; Heidrun Plarre et al. (2014). A new intracellular bacterium, Candidatus Similichlamydia labri sp. nov. (Chlamydiaceae) producing epitheliocysts in ballan wrasse, Labrus bergylta (Pisces, Labridae). (external link)
• Aina-Cathrine Øvergård; Sonal Patel; Ole Jakob Nøstbakken et al. (2013). Atlantic halibut (Hippoglossus hippoglossus L.) T-cell and cytokine response after vaccination and challenge with nodavirus. (external link)
• Aina-Cathrine Øvergård; Ina Nepstad; Audun H. Nerland et al. (2012). Characterisation and expression analysis of the Atlantic halibut (Hippoglossus hippoglosssus L.) cytokines: IL-1β, IL-6, IL-11, IL-12β and IFNγ. (external link)
• Aina-Cathrine Øvergård; Audun Helge Nerland; Ingrid Uglenes Fiksdal et al. (2012). Atlantic halibut experimentally infected with nodavirus shows increased levels of T-cell marker and IFN gamma transcripts. (external link)
• Aina-Cathrine Øvergård; Ingrid Uglenes Fiksdal; Audun H. Nerland et al. (2011). Expression of T-cell markers during Atlantic halibut (Hippoglossus hippoglossus L.) ontogenesis. (external link)
• Aina-Cathrine Øvergård; Audun H. Nerland; Sonal Patel (2010). Evaluation of potential reference genes for real time RT-PCR studies in Atlantic halibut (Hippoglossus Hippoglossus L.); during development, in tissues of healthy and NNV-injected fish, and in anterior kidney leucocytes. (external link)
• Aina-Cathrine Øvergård; Audun H. Nerland; Sonal Patel (2010). Cloning, characterization, and expression pattern of Atlantic halibut (Hippoglossus hippoglossus L.) CD4-2, Lck, and ZAP-70. (external link)
• Aina-Cathrine Øvergård; Ivar Hordvik; Audun H. Nerland et al. (2009). Cloning and expression analysis of Atlantic halibut (Hippoglossus hippoglossus) CD3 genes. (external link)
• Sonal Patel; Aina-Cathrine Øvergård; Audun H. Nerland (2009). A CD4 homologue in Atlantic halibut (Hippoglossus hippoglossus): Molecular cloning and characterisation. (external link)
• Sonal Patel; Aina-Cathrine Øvergård; Audun H. Nerland (2008). CD8 alpha and CD8 beta in Atlantic halibut, Hippoglossus hippoglossus: Cloning, characterization and gene expression during viral and bacterial infection. (external link)

Academic book chapter

• Audun H. Nerland; Aina-Cathrine Øvergård; Sonal Patel (2011). Viruses of Fish. (external link)

Conference abstract

• Helena Marie Doherty Midtbø; Gyri Teien Haugland; Andreas Borchel et al. (2023). LsLGP3 from Salmon Louse (Lepeophtheirus salmonis) Causes Cell Death in Atlantic salmon (Salmo salar) Leukocytes. (external link)

Conference lecture

• M.J. McGowan; James E. Bron; M. Bekaert et al. (2025). Free-swimming copepodid salmon lice (Lepeophtheirus salmonis) undergo a transcriptomic shift when exposed to salmonid host cues. (external link)
• Nicholas Andrew Robinson; Lene Sveen; Muhammad Luqman Aslam et al. (2025). The cellular and genetic response to sea lice infection: How might we use this knowledge to improve Atlantic salmon host-resistance to sea lice?. (external link)
• Mette Serine Wesmajervi Breiland; Nicholas Andrew Robinson; Tone-Kari K Østbye et al. (2024). Transkriptomikk og genredigering som verktøy for å utforske genetiske mekanismer som kan gi artsspesifkk resistens mot lakselus. (external link)
• Nicholas Andrew Robinson; Tone-Kari K Østbye; Sarah Salisbury et al. (2024). Use of transcriptomics and gene editing to explore genetic mechanisms giving species-specific host-resistance to sea lice. (external link)
• Anne Elisabeth Bjune; Gunnar Bratbak; Sigrunn Eliassen et al. (2023). Omlegging fra tradisjonelle forelesninger til studentaktiv læring – eksempel fra et grunnemne i biolog. (external link)
• Helena Marie Doherty Midtbø; Gyri Teien Haugland; Aina-Cathrine Øvergård (2022). Does Salmon louse Have an Immune Dampening Effect on Atlantic Salmon?. (external link)
• Aina-Cathrine Øvergård (2020). Grunnleggende lusebiologi – hva vet vi, og hva skal studeres.. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Sindre Grotmol et al. (2019). Lusespytt modulerer laksens immunrespons. (external link)
• Aina-Cathrine Øvergård; Frank Nilsen; Noelia Nuñez-Ortiz et al. (2019). THE SALMON LOUSE (LEPEOPHTHEIRUS SALMONIS) SALIVARY GLAND SECRETES IMMUNE REGULATORY PROTEINS. (external link)
• Selina Våge; Mariann Eilertsen; Aina-Cathrine Øvergård et al. (2019). Learning outcomes at master level in biology. Current expectations and guidelines for the future. (external link)
• Sussie Dalvin; Louise VG Jørgensen; Per W. Kania et al. (2018). MORPHOLOGICAL AND IMMUNOLOGICAL CHANGES IN RAINBOW TROUT SKIN IN RESPONSE TO SALMON LOUSE INFECTION. (external link)
• Jordan Poley; Laura Braden; Dylan Michaud et al. (2018). Excretory and Secretory Factors of the Salmon Louse: Genomic Characterization, Effects on Feeding, and Impacts on Host Immunity. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Sindre Grotmol et al. (2018). DO Lepeophtheirus salmonis RHABDOVIRUSES (LsRVs) DAMPEN THE LOCAL SKIN INFLAMMATORY RESPONSE IN ATLANTIC SALMON Salmo salar?. (external link)
• Sussie Dalvin; Aina-Cathrine Øvergård; Christiane Eichner et al. (2017). Do prostaglandins produced by lepeophtheirus salmonis affect the interaction between the parasite and the fish?. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Ewa Harasimczuk et al. (2017). Exocrine glands of Lepeophtheirus salmonis and secretion of possible immune regulatory proteins.. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Ewa Harasimczuk et al. (2016). Distribution and Development of salmon louse Lepeophtheirus salmonis exocrine glands. (external link)
• Christiane Eichner; Aina-Cathrine Øvergård; Frank Nilsen et al. (2014). Characterization and knock-down of a putative prostaglandin e synthase found in Lepeophtheirus salmonis. (external link)
• Audun H. Nerland; Aina-Cathrine Øvergård; Sonal Patel (2010). Molecular approaches for development of vaccines against intracellular fish pathogens. (external link)
• Aina-Cathrine Øvergård; Audun H. Nerland; Sonal Patel (2009). Relativ uttrykning av T-celle markører i tidlige livsstadier hos Atlantisk kveite (Hippoglossus hippoglossus). (external link)
• Sonal Patel; Aina-Cathrine Øvergård; Elin Sørhus et al. (2009). B and T cell markers during Atlantic halibut (Hippoglossus hippoglossus) ontogenesis. (external link)

Conference poster

• Ingeborg Emilie Berg Kahrs; Andreas Borchel; Patrick Alexander Nelson et al. (2025). Polyvalent DNA vaccines targeting salmon louse labial gland proteins. (external link)
• Andreas Borchel; Helena Marie Doherty Midtbø; Aina-Cathrine Øvergård (2025). The local transcriptomic response of Atlantic salmon skin to salmon louse chalimi and adults. (external link)
• Aina-Cathrine Øvergård; Lars Are Hamre; Ewa Harasimczuk et al. (2017). Eksokrine kjertler i lakselus (Lepeophtheirus salmonis). (external link)
• Michael Dondrup; Wei Zhang; Zhaoran Zhou et al. (2016). Licebase-a species focused resource for sea lice including an RNAi LIMS andtools for data analysis and genome annotation. (external link)

Doctoral thesis (PhD)

• Aina-Cathrine Øvergård (2012). T-cells and cytokines of Atlantic halibut (Hippoglossus hippoglossus L.) - Gene expression levels during ontogenesis, vaccination and experimental nodavirus infection. (external link)

Lecture

• Andreas Borchel; Helena Marie Doherty Midtbø; Aina-Cathrine Øvergård (2025). Lokal transkripsjonsregulering i lakseskinn som respons på forskjellige livsstadier av lakselus. (external link)
• Patrick Alexander Nelson; Andreas Borchel; Aina-Cathrine Øvergård (2025). Utvikling av en DNA-vaksine rettet mot lakselusspytt i Atlanterhavslaks. (external link)
• Aina-Cathrine Øvergård; Andreas Borchel (2024). Utvikling av DNA vaksine rettet mot lakselusspytt i Atlanterhavslaks. (external link)

Master’s thesis

• Oppedal Henrikke; Samantha Bui; Aina-Cathrine Øvergård (2021). Refilling behaviour of Atlantic salmon (Salmo salar) with different air-dome heights. (external link)

Popular science article

• Aina-Cathrine Øvergård; Lars Are Hamre (2020). Skottelusen: en kilde til viktig kunnskap, men også en mulig fremtidig trussel?. (external link)

Popular science book chapter

• Sonal Patel; Aina-Cathrine Øvergård; Ingrid Uglenes Fiksdal et al. (2011). Tidlig vaksinering – mot sin hensikt. (external link)

Research report

• Nina Sandlund; Sussie Trine Dalvin; Aina-Cathrine Øvergård et al. (2014). Sekvensering av havet – fremtidens teknologi. (external link)

See a complete overview of publications in NVA.

SaliVax (https://www.fhf.no/prosjekter/prosjektbasen/901760/)

SaliFilaVax (https://www.fhf.no/prosjekter/prosjektbasen/901868/)