Time-series transcriptomic analysis of the kelp grouper Epinephelus moara in response to low salinity stress

Abstract

The Kelp grouper Epinephelus moara is one of the most widely consumed and economically important marine fish in China. The species can tolerate a wide range of salinity, but genomic resources are not available, and the molecular mechanisms underlying adaptation to salinity at the transcriptomic level remain largely unclear. In this study, the transcriptomic responses of the liver of E. moara under low salinity were investigated using the Illumina digital gene expression system. After de novo assembly, 499,356 transcripts were generated and contributed 445,068 unigenes. A total of 14, 19, 33 and 3101 genes were differentially expressed following exposure to low salinity stress for 2, 6, 24 and 48 h, respectively. Only two genes were differentially expressed in all groups. Four genes related to metabolism and ambient salinity adaption were randomly selected to validate the differentially expressed genes (DEGs) by real-time PCR. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to analyse the functional significance of DEGs, including those responding to salinity through diverse biological processes, cellular components, molecular functions, and pathways associated with metabolic and osmotic responses. This work provides new insight into the response to salinity challenges in E. moara, and the findings expand our knowledge of the molecular basis of metabolic regulation mechanisms in this species. Additionally, the transcriptional data provide a valuable resource for future molecular and genetic studies on E. moara.

Comprehensive Transcriptional Changes in the Liver of Kanglang White Minnow (Anabarilius grahami) in Response to the Infection of Parasite Ichthyophthirius multifiliis

“…We have to admit that we did not cover these issues, and the control group in our study only represented the samples at time zero before infection but not the simultaneous non-infected control samples that should be collected at the same time as early-or later-infected stages. Using time zero as the control seems like a simply compromise choice, but it has been widely accepted for pathogen challenging studies in various fishes [19,20,29,42].…”