Characterising the Atlantic cod immune system with single-cell transcriptomics
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 seq...
Published in: | Frontiers in Immunology |
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Main Author: | |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
2022
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Subjects: | |
Online Access: | http://hdl.handle.net/10852/94558 http://urn.nb.no/URN:NBN:no-97102 |
Summary: | 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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