Project description:Dissolved oxygen (DO) is the basis of fish survival, and proper DO level is an important condition to ensure the normal growth of fish. Hypoxic environment is prone to disturb the normal breathing and metabolism of fish, which in turn affects their growth and survival. Gill tissue is the respiratory organs of fish and is in direct contact with the external environment. However, there are few reports on the molecular regulatory mechanism of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) gill tissues in response to hypoxia. Here, we first examine the hypoxia-induced damage of gill tissue by hematoxylin-eosin staining, and then constructed miRNA and mRNA libraries of GIFT gill tissue at 96h of hypoxia stress by a high-throughput sequencing technology, each library has three biological replicates. Gill lamellae of GIFT showed capillary rupture and red blood cell enlargement and overflow under hypoxia stress. Transcription sequencing results showed that the clean reads of miRNA libraries were 9,627,953-13,544,660; the clean reads of mRNA libraries were 43,817,776-53,130,102. Based on the miRNA-mRNA pairs screening principles and mRNA sequencing results, we selected and verified seven differentially expressed miRNAs and their potential target genes. The sequencing results were consistent with the qRT-PCR validation results. These selected miRNA-mRNA pairs are mainly concentrated in the signaling pathways of immune response and metabolic regulation. This study provides new insights into the mechanisms of fish adaptation under hypoxic stress.
Project description:Dissolved oxygen (DO) in cultured water is one of the important environment factor in fish farming. Hypoxic environment affects fish growth, metabolism and immune system. Multi-omics integrative analysis helps to uncover the underlying molecular mechanisms. In this study, the 96h median lethal hypoxia (96h-LH50) for Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus) was first analyzed by linear interpolation. We built control (5mg/l) and hypoxic stress (96h-LH50) groups, and extracted the liver tissues for high-throughput transcriptome and metabolome sequencing. The identification and quantification results of metabolites showed that a total of 19656 metabolites had been obtained, of which 10390 were annotated. There were 3028 differentially expressed (DE) metabolites, of which 1596 metabolites were up-regulated and 1432 metabolites were down-regulated. We obtained 2375 DE genes, of which 1201 genes were up-regulated and 1174 genes were down-regulated. We verified 8 DE genes by quantitative real-time PCR. Our finding reveals the changes in metabolites and genes expression of GIFT and facilitate the understanding of regulatory pathways under hypoxic stress, which will help reduce the damage caused by hypoxic stress during culture.
Project description:Dissolved oxygen (DO) is the basis of fish survival, and proper DO level is an important condition to ensure the normal growth of fish. Hypoxic environment is prone to disturb the normal breathing and metabolism of fish, which in turn affects their growth and survival. Gill tissue is the respiratory organs of fish and is in direct contact with the external environment. However, there are few reports on the molecular regulatory mechanism of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) gill tissues in response to hypoxia. Here, we first examine the hypoxia-induced damage of gill tissue by hematoxylin-eosin staining, and then constructed miRNA and mRNA libraries of GIFT gill tissue at 96h of hypoxia stress by a high-throughput sequencing technology, each library has three biological replicates. Gill lamellae of GIFT showed capillary rupture and red blood cell enlargement and overflow under hypoxia stress. Transcription sequencing results showed that the clean reads of miRNA libraries were 9,627,953-13,544,660; the clean reads of mRNA libraries were 43,817,776-53,130,102. Based on the miRNA-mRNA pairs screening principles and mRNA sequencing results, we selected and verified seven differentially expressed miRNAs and their potential target genes. The sequencing results were consistent with the qRT-PCR validation results. These selected miRNA-mRNA pairs are mainly concentrated in the signaling pathways of immune response and metabolic regulation. This study provides new insights into the mechanisms of fish adaptation under hypoxic stress.
Project description:Differential gene expression profiles and alternative splicing events in the gill tissues of the Nile tilapia in response to acute hypoxia
Project description:Transcriptomic analysis reveals abundant differential gene expression and alternative splicing events in the heart tissues of the Nile tilapia in response to acute hypoxia
Project description:Mapping active promoters by ChIP-seq profiling of H3K4me3 in cichlid fish - a first step to uncover cis-regulatory elements in ecological model teleosts
Project description:GIFT is a type of freshwater farmed fish with high economic value and nutritional value. The liver is an important organ of fish metabolism. Once it is damaged or the disease occurs, it will lead to metabolic disorders and decreased disease resistance, and may cause other secondary diseases. In the high-density intensive culture of tilapia, the feed nutrition is not balanced, especially the addition of high-fat feed. High fat content can accelerate the growth of fish, but long-term feeding of high-fat diet can lead to metabolic disorders of fish, accumulation of fat in the body, easy to cause fatty liver, and ultimately death due to liver necrosis or hemorrhage, seriously affecting the breeding benefits. The main purpose of this study was to investigate the effects of apple peel added to feed on liver fat metabolism and fat deposition in tilapia tilapia; use transcriptomics to analyze related signal regulation pathways, focusing on fat metabolism and inflammatory response; and finally screening differentially expressed genes. The development of this study is helpful to understand the molecular mechanism of apple peel extract powder-mediated liver fat metabolism and inflammatory response in GIFT, and relieve liver stress. It also provides theoretical support for the application of apple peel extract powder as a feed additiion in aquatic products.