Comparative transcriptome profiling of selected osmotic regulatory proteins in the gill during seawater acclimation of chum salmon (Oncorhynchus keta) fry

Sang Yoon Lee,Yi Kyung Kim,Hwa Jin Lee

doi:10.1038/s41598-020-58915-6

Sang Yoon Lee, Yi Kyung Kim + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-58915-6

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Journal: Scientific Reports	Publication Date: Feb 6, 2020
Citations: 20	License type: open-access

Affiliation: Gangneung–Wonju National University

Abstract

Salmonid fishes, chum salmon (Oncorhynchus keta) have the developed adaptive strategy to withstand wide salinity changes from the early life stage. This study investigated gene expression patterns of cell membrane proteins in the gill of chum salmon fry on the transcriptome level by tracking the salinity acclimation of the fish in changing environments ranging from freshwater (0 ppt) to brackish water (17.5 ppt) to seawater (35 ppt). Using GO analysis of DEGs, the known osmoregulatory genes and their functional groups such as ion transport, transmembrane transporter activity and metal ion binding were identified. The expression patterns of membrane protein genes, including pump-mediated protein (NKA, CFTR), carrier-mediated protein (NKCC, NHE3) and channel-mediated protein (AQP) were similar to those of other salmonid fishes in the smolt or adult stages. Based on the protein-protein interaction analysis between transmembrane proteins and other related genes, we identified osmotic-related genes expressed with salinity changes and analyzed their expression patterns. The findings of this study may facilitate the disentangling of the genetic basis of chum salmon and better able an understanding of the osmophysiology of the species.

Highlights

Salmonid fishes, chum salmon (Oncorhynchus keta) have the developed adaptive strategy to withstand wide salinity changes from the early life stage
Most of the salmonid fishes currently in the market are dominated by cultured Atlantic salmon (Salmo salar), whereas the production of chum salmon mostly depends on fishing (FAO, 2019)
Chum salmon are a major species of salmonid fishes that return to Korea, and if the feed and the aquaculture system are improved with the help of research on seawater adaptability and growth, they can be developed as a promising aquaculture species in the future

Summary

Introduction

Chum salmon (Oncorhynchus keta) have the developed adaptive strategy to withstand wide salinity changes from the early life stage. This study investigated gene expression patterns of cell membrane proteins in the gill of chum salmon fry on the transcriptome level by tracking the salinity acclimation of the fish in changing environments ranging from freshwater (0 ppt) to brackish water (17.5 ppt) to seawater (35 ppt). The gill is a primary organ to detect changes in external osmotic pressure and promotes the compensatory active absorption or the excretion of monovalent ions (sodium, potassium, chloride) to maintain the osmolality of body fluids at levels equivalent to approximately one-third of the seawater osmolality[16,17,18]. The gill tissues play crucial roles in physical processes such as gas exchange, nitrogenous waste excretion, and acid-base balance[20]

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