Disputation: Naomi Croft Guslund

PhD candidate Naomi Croft Guslund at the Department of Biosciences will be defending the thesis "Characterising the Atlantic cod immune system with single-cell transcriptomics" for the degree of PhD.

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Naomi Croft Guslund Photo: private.

The trial lecture is: "CD4+ T cell subsets in autoimmunity: when helpers become unhelpful".

Time and place: June 23, 2022 10:15 AM, Zoom and Nucleus, Bikuben, The Kristine Bonnevie building.

Main research findings

The major features of our adaptive immune system originated 500 million years ago and are common to all vertebrates. Until recently, it was assumed that all components of the adaptive immune system were such a beneficial evolutionary acquisition that they have been maintained in all species. DNA sequencing of the Atlantic cod genome and that of other cod family members revealed a loss of some genes essential for adaptive immunity in mammals. Why the loss of these genes in an ancestor of Atlantic cod has resulted in evolutionary success for cod and its cousins is a mystery.

To understand the cellular organisation and activity of the Atlantic cod immune system, we isolated individual immune cells and examined the activity of about 20, 000 genes on a single-cell level (tens of thousands of cells). This allowed us to describe the immune cell populations present in the cod. We found all major immune cells, except those dependent on the lost genes. We also describe the cellular responses to vaccination and challenge with Vibrio anguillarum, a commonly encountered cold-water pathogen, and find activation of immune defense mechanisms in immunised fish, which could explain why they are protected against vibriosis.

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Adjudication committee

Project leader Dr. Jeremy Swann, Max Planck Institute

Professor Gyri Teien Haugland, University of Bergen

Associate Professor Sjannie Lefevre, University of Oslo

Chair of defence

Professor Marianne Fyhn, University of Oslo


Shuo-Wang Qiao, University of Oslo

Finn-Eirik Johansen, University of Oslo

Kjetill Jakobsen, University of Oslo

Monica Solbakken, University of Oslo

Published June 9, 2022 9:45 AM - Last modified Sep. 16, 2022 11:00 AM