The integrated analyses of metabolomics and transcriptomics in gill of GIFT tilapia in response to long term salinity challenge

Abstract

The Nile tilapia, Oreochromis niloticus, GIFT strain is suggested to be a good candidate for culture in brackish water. Gill is regarded as the dominate site of osmo-regulation. Recently, the mechanisms underlying salinity challenge in gill of tilapia are getting increasing attention. In this study, an integrated analysis of metabolomics and transcriptomics on gill of GIFT tilapia under salinity 17 and 27 challenge for three and a half months are conducted. 1164 DEGs in the comparison 0 vs 17 and 910 DEGs in the comparison 0 vs 27 are identified. Many typical genes involved in osmo-regulation are found, including calcium/calmodulin-dependent protein kinase II beta 1, Aquaporin 3, Potassium channel subfamily K member, chloride channel 2, Solute Carrier Family 12 Member 8, Solute Carrier Family 12 Member 2, Na +/K + ATPase. Some biosynthesis, metabolism, energy or transport related pathways are over-represented, such as Synthesis of UDP-N-acetyl-glucosamine, Synthesis of substrates in N-glycan biosynthesis, Biosynthesis of DPAn-3 SPMs, Metabolism of lipids, Gluconeogenesis and SLC-mediated transmembrane transport. In addition, totally 23 metabolites are significantly responded in gill under salinity challenge. Of which, 11 metabolites including 12-Hydroxyeicosatetraenoic acid and choline are significantly down-regulated and 8 metabolites including adenine, Lys-Pro, inosine are significantly up-regulated under salinity challenge. Our study provides an important database for further functional analysis of osmo-regulation in gill of Nile tilapia.