Transcriptome Analysis of Marbled Rockfish Sebastiscus marmoratus under Salinity Stress

SIMPLE SUMMARY: Changes in salinity can have an impact on the physiological processes of fish. In this study, RNA-seq sequencing was used to detect and analyze the differential gene expression of Sebastiscus marmoratus in salinity fluctuations and to explore the genes and pathways related to salinity stress. The results demonstrated that pik3r6b, cPLA2γ-like, and WSB1 were differentially expressed in all three groups. All three genes were highly expressed in the high-salt group, with wsb1 being more expressed than pik3r6b and cPLA2γ-like. The results of this study provide some basic theoretical references for the salinity adaptation mechanism of Sebastiscus marmoratus. ABSTRACT: The marbled rockfish, Sebastiscus marmoratus, belongs to the euryhaline fish and is an oviparous scleractinian fish. There are few studies on the adaptation mechanism, functional genes, and related pathways of S. marmoratus and salinity. The results showed that a total of 72.1 GB of clean reads were obtained and all clean reads annotated a total of 25,278 Unigenes, of which 2,160 were novel genes. Compared to 20‰, 479 and 520 differential genes were obtained for 35‰ and 10‰, respectively. Gene ontology (GO) enrichment analysis revealed significant enrichment in protein binding, ion binding, ATP binding, and catalytic activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that differentially expressed genes significantly expressed under salinity stress were mainly involved in the pathways of the cytochrome P450 metabolism of xenobiotics, tryptophan metabolism, cellular senescence, and calcium signaling pathways. Among them, pik3r6b, cPLA2γ-like, and WSB1 were differentially expressed in all three groups, and they were associated with apoptosis, inflammation, DNA damage, immune regulation, and other physiological processes. Six differentially expressed genes were randomly selected for qRT-PCR validation, and the results showed that the transcriptomic data were of high confidence.