Differential Transcriptomic and Metabolomic Responses in the Liver of Nile Tilapia (Oreochromis niloticus) Exposed to Acute Ammonia

• Published in: Marine biotechnology (New York, N.Y.) Vol. 21; no. 4; pp. 488 - 502
• Main Authors: Zhu, Zong Xian, Jiang, Dan Li, Li, Bi Jun, Qin, Hui, Meng, Zi Ning, Lin, Hao Ran, Xia, Jun Hong
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2019; Springer Nature B.V
• Subjects: Ammonia; Ammonia - toxicity; Animals; Aquaculture; Aquaculture techniques; Aquatic animals; Biological stress; Biomedical and Life Sciences; Biosynthesis; Breeding; Cholesterol; Cholesterol - metabolism; Energy conservation; Energy metabolism; Engineering; Environmental Exposure; Fish; Fish Proteins - classification; Fish Proteins - genetics; Fish Proteins - metabolism; Freshwater & Marine Ecology; Freshwater fishes; Fumarates - metabolism; Fumaric acid; Gas chromatography; Gene expression; Gene Expression Profiling; Gene Expression Regulation; Gene Ontology; Glycerol; Glycerophosphates - metabolism; Life Sciences; Lipid Metabolism; Lipids; Liver; Liver - drug effects; Liver - metabolism; Malates - metabolism; Malic acid; Metabolism; Metabolites; Metabolome - genetics; Metabolomics; Microbiology; Mitochondria; Molecular Sequence Annotation; Nitrogen; Nucleic acids; Oreochromis niloticus; Organizations; Original Article; Phosphates; Recirculating aquaculture systems; Ribonucleic acid; RNA; Steroids; Stress, Physiological - genetics; Tilapia; Tilapia - genetics; Tilapia - metabolism; Tissue; Toxicity; Transcriptome; Water Pollutants, Chemical - toxicity; Zoology; Metabolomics; RNA-seq; Nile tilapia; Ammonia-nitrogen tolerance
• ISSN: 1436-2228; 1436-2236
• DOI: 10.1007/s10126-019-09897-8

Ammonia is toxic to aquatic animal. Currently, only limited works were reported on the responses of aquatic animals after ammonia exposure using “omics” technologies. Tilapia suffers from the stress of ammonia-nitrogen during intensive recirculating aquaculture. Optimizing ammonia stress tolerance has become an important issue in tilapia breeding. The molecular and biochemical mechanisms of ammonia-nitrogen toxicity have not been understood comprehensively in tilapia yet. In this study, using RNA-seq and gas chromatograph system coupled with a Pegasus HT time-of-flight mass spectrometer (GC-TOF-MS) techniques, we investigated differential expressed genes (DEGs) and metabolomes in the liver at 6 h post-challenges (6 hpc) and 24 h post-challenges (24 hpc) under high concentration of ammonia-nitrogen treatment. We detected 2258 DEGs at 6 hpc and 315 DEGs at 24 hpc. Functional enrichment analysis indicated that DEGs were significantly associated with cholesterol biosynthesis, steroid and lipid metabolism, energy conservation, and mitochondrial tissue organization. Metabolomic analysis detected 31 and 36 metabolites showing significant responses to ammonia-nitrogen stress at 6 and 24 hpc, respectively. D-(Glycerol 1-phosphate), fumaric acid, and L-malic acid were found significantly down-regulated at both 6 and 24 hpc. The integrative analysis of transcriptomics and metabolomics suggested considerable alterations and precise control of gene expression at both physiological and molecular levels in response to the stress of ammonia-nitrogen in tilapia.