My work is connected to the Sea Lice Research Center at UiB within the Fish Health Group.

I have a lot of experience with molecular biology and genetics of salmon lice, identifying new gene functions (1, 2), and identifying the reaction of lice to their environment, like heat or reduced salinity. I have employed RNA-Sequencing to analyse gene expression of salmon lice and their salmon hosts.

Previously taught:

BIF210 - Molecular Biology Methods

BIO103 - Cell Biology and Genetics - Zoology part

Academic article

• Borchel, Andreas; Nilsen, Frank (2025). Transcriptomic insights into the low-salinity tolerance of the sea louse Caligus elongatus. (external link)
• Øvergård, Aina-Cathrine; Borchel, Andreas; Eichner, Christiane et al. (2025). The generalist Caligus elongatus is better at dampening the Atlantic salmon immune response than the salmonid specialist Lepeophtheirus salmonis. (external link)
• Midtbø, Helena Marie Doherty; Eichner, Christiane; Hamre, Lars Are et al. (2024). Salmon louse labial gland enzymes: implications for host settlement and immune modulation. (external link)
• Midtbø, Helena Marie Doherty; Borchel, Andreas; Morton, Hugh Craig 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)
• Borchel, Andreas; Eichner, Christiane; Øvergård, Aina-Cathrine (2023). Mining Lepeophtheirus salmonis RNA-Seq data for qPCR reference genes and their application in Caligus elongatus. (external link)
• Øvergård, Aina-Cathrine; Eichner, Christiane; Nuñez-Ortiz, Noelia et al. (2023). Transcriptomic and targeted immune transcript analyses confirm localized skin immune responses in Atlantic salmon towards the salmon louse. (external link)
• Borchel, Andreas; Heggland, Erna Irene; Nilsen, Frank (2023). Without a pinch of salt: effect of low salinity on eggs and nauplii of the salmon louse (Lepeophtheirus salmonis). (external link)
• Borchel, Andreas; Komisarczuk, Anna Zofia; Nilsen, Frank (2022). Sex differences in the early life stages of the salmon louse Lepeophtheirus salmonis (Copepoda: Caligidae). (external link)
• Borchel, Andreas; Heggland, Erna Irene; Nilsen, Frank (2021). The transcriptomic response of adult salmon lice (Lepeophtheirus salmonis) to reduced salinity. (external link)
• Rebl, Alexander; Korytář, Tomáš; Borchel, Andreas et al. (2020). The synergistic interaction of thermal stress coupled with overstocking strongly modulates the transcriptomic activity and immune capacity of rainbow trout (Oncorhynchus mykiss). (external link)
• Borchel, Andreas; Verleih, Marieke; Kühn, Carsten et al. (2019). Evolutionary expression differences of creatine synthesis-related genes: Implications for skeletal muscle metabolism in fish. (external link)
• Borchel, Andreas; Kongshaug, Heidi; Nilsen, Frank (2019). Identification and Description of the Key Molecular Components of the Egg Strings of the Salmon Louse (Lepeophtheirus salmonis). (external link)
• Verleih, Marieke; Borchel, Andreas; Rebl, Alexander et al. (2019). A molecular survey of programmed cell death in rainbow trout: Structural and functional specifications of apoptotic key molecules. (external link)
• Borchel, Andreas; Nilsen, Frank (2018). A novel gene‐family involved in spermatophore generation in the economically important salmon louse Lepeophtheirus salmonis. (external link)
• Borchel, Andreas; Komisarczuk, Anna Zofia; Rebl, Alexander et al. (2017). Systematic identification and characterization of stress-inducible heat shock proteins (HSPs) in the salmon louse (Lepeophtheirus salmonis). (external link)
• Borchel, Andreas; Verleih, Marieke; Rebl, Alexander et al. (2017). Identification of genes involved in cold-shock response in rainbow trout (Oncorhynchus mykiss). (external link)
• Rebl, Alexander; Zebunke, Manuela; Borchel, Andreas et al. (2017). Microarray-predicted marker genes and molecular pathways indicating crowding stress in rainbow trout (Oncorhynchus mykiss). (external link)
• Brietzke, Andreas; Borchel, Andreas; Altmann, Simone et al. (2016). Transcriptome sequencing of maraena whitefish (Coregonus maraena). (external link)

Lecture

• Borchel, Andreas; Midtbø, Helena Marie Doherty; Øvergård, Aina-Cathrine (2025). Lokal transkripsjonsregulering i lakseskinn som respons på forskjellige livsstadier av lakselus. (external link)
• Nelson, Patrick Alexander; Borchel, Andreas; Øvergård, Aina-Cathrine (2025). Utvikling av en DNA-vaksine rettet mot lakselusspytt i Atlanterhavslaks. (external link)
• Øvergård, Aina-Cathrine; Borchel, Andreas (2024). Utvikling av DNA vaksine rettet mot lakselusspytt i Atlanterhavslaks. (external link)
• Borchel, Andreas; Kongshaug, Heidi; Nilsen, Frank (2019). Main components of the egg strings of salmon lice. (external link)
• Borchel, Andreas; Nilsen, Frank (2017). Understanding male reproduction in sea lice. (external link)

Academic literature review

• Borchel, Andreas; Nilsen, Frank (2025). A Review of the Salmon Louse (Lepeophtheirus salmonis) Hyposalinity Responses and the Efficacy of Freshwater Delousing. (external link)

Academic lecture

• Borchel, Andreas; Nilsen, Frank (2022). Molekylære tilpasningsmekanismer av lakselus til brakk- og ferskvann. (external link)
• Borchel, Andreas; Nilsen, Frank (2022). Molecular responses of salmon lice to reduced salinity. (external link)
• Borchel, Andreas; Nilsen, Frank (2018). Sex in salmon lice (Lepeophtheirus salmonis). (external link)
• Borchel, Andreas (2018). Sex determination and reproduction in the sea louse – the biggest enemy of salmon farming. (external link)
• Borchel, Andreas; Nilsen, Frank (2017). Characterization of genes involved in the male reproductive system of salmon louse (Lepeophtheirus salmonis). (external link)

See a complete overview of publications in Cristin.

I am currently working on the FHF-funded project SaliFilaVax the successor of, Salivax, in which we try to develop and optimise a DNA vaccine targeting the proteins secreted from the salmon louse onto the fish.

Nanolus is led by Marineholem RASLab AS and is analysing the suitability of ion-modified water as an anti-louse treatment. I'm the project reponsible at UiB and will perform transcriptomic studies on lice treated with this water.

I was also involved in the Microboost project, which is funded by the EEA and Norway Grants and is a cooperation with several portuguese partners. In this project we try to use microalgae as functional food ingredient to improve the immune system of fish and prevent lice infestation.

Previously I have worked on the projects Freshnet and Freshnet 2 where we looked at the osmoregulation of salmon lice. Additionally I was involved in the project ModuLus which analysed the interaction of salmon lice and their hosts.