RT Journal Article
SR Electronic
T1 A single nuclei transcriptomic analysis of the Atlantic salmon gill through smoltification and seawater transfer
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.09.03.281337
DO 10.1101/2020.09.03.281337
A1 Alexander C. West
A1 Yasutaka Mizoro
A1 Shona H. Wood
A1 Louise Ince
A1 Marianne Iversen
A1 Even H. Jørgensen
A1 Torfinn Nome
A1 Simen Rød Sandve
A1 Andrew S. I. Loudon
A1 David G. Hazlerigg
YR 2020
UL http://biorxiv.org/content/early/2020/09/03/2020.09.03.281337.abstract
AB Anadromous salmonids begin life adapted to the freshwater environments of their natal streams before a developmental transition, known as smoltification, transforms them into marine-adapted fish. In the wild, the extending photoperiods of spring stimulates smoltification, typified by radical reprogramming of the gill from an ion-absorbing organ to ion-excreting organ. Prior work has highlighted the role of specialized “mitochondrion-rich” cells in delivering this phenotype. However, transcriptomic studies identify thousands of smoltification-driven differentially regulated genes, indicating that smoltification causes a multifaceted, multicellular change; but direct evidence of this is lacking.Here, we use single-nuclei RNAseq to characterize the Atlantic salmon gill during smoltification and seawater transfer. We identify 20 distinct clusters of nuclei, including known, but also novel gill cell types. These data allow us to isolate cluster-specific, smoltification-induced changes in gene expression. We also show how cellular make-up of the gill changes through smoltification. As expected we noted an increase in the proportion of seawater mitochondrion-rich cells, however, we also identify a reduction of several immune-related cells. Overall, our results provide unrivaled detail of the cellular complexity in the gill, and suggest that smoltification triggers unexpected immune reprogramming directly preceding seawater entry.Competing Interest StatementThe authors have declared no competing interest.