Project description:Triple-negative breast cancer (TNBC) lacks therapeutic target and is difficult to treat. We report a cationic antimicrobial peptide (CAP), tilapia piscidin 4 (TP4), derived from Nile tilapia (Oreochromis niloticus), selectively toxic to TNBC. Here we aim to identify potential target in TNBC cell response to TP4 treatment by microarray study and to further address the role of TP4-resposive genes involved in TNBC cell death.
Project description:Evolutionary alterations to cis-regulatory sequences are likely to cause adaptive phenotypic complexity, through orchestrating changes in cellular proliferation, identity and communication. For non-model organisms with adaptive key-innovations, patterns of regulatory evolution have been predominantly limited to targeted sequence-based analyses. Chromatin-immunoprecipitation with high-throughput sequencing (ChIP-seq) is a technology that has only been used in genetic model systems and is a powerful experimental tool to screen for active cis-regulatory elements. Here, we show that it can also be used in ecological model systems and permits genome-wide functional exploration of cis-regulatory elements. As a proof of concept, we use ChIP-seq technology in adult fin tissue of the cichlid fish Oreochromis niloticus to map active promoter elements, as indicated by occupancy of trimethylated Histone H3 Lysine 4 (H3K4me3). The fact that cichlids are one of the most phenotypically diverse and species-rich families of vertebrates could make them a perfect model system for the further in-depth analysis of the evolution of transcriptional regulation. examination of H3K4me3 in adult fin tissue of the Nile tilapia (Oreochromis niloticus)
Project description:The elucidation of microRNA function and evolution depends on the identification and characterization of miRNA repertoire of strategic organisms, as the fast evolving cichlid fishes. Using RNA-seq and comparative genomics we carried out an in-depth report of miRNAs in Nile tilapia (Oreochromis niloticus). Our results enlarge vertebrate miRNAs collection and reveal a notable differential expression of miRNAs arms and isoforms influenced by sex and developmental life stage, providing a better picture of the evolutionary and spatiotemporal dynamics of miRNAs.
Project description:Elongation of very long-chain fatty acids protein 6 (Elovl6) is a crucial enzyme in the synthesis of endogenous fatty acids, which participates in the energy balance and metabolic diseases. The main objective of this study was to explore the molecular characterization of elovl6 and study regulatory mechanism of elovl6 on male Nile tilapia, Oreochromis niloticus. In the present study, the full-length cDNA of Nile tilapia elovl6 was 2255 bp, comprising a 5'-UTR of 193 bp, an ORF of 810 bp, and a 3'-UTR of 1252 bp, encoding 269 amino acids that possesses the characteristic features of Elovl proteins. The transcription expression of elovl6 transcripts showed differential expression in different tissues and fed with different lipid sources diet. Antisense RNA technology was used to knock-down elovl6 in Nile tilapia. Compared with the control treatments (transfected with ultrapure water (control) or the blank expression vector (negative control)), knockdown elovl6 altered hepatic morphology, Long chain fatty acid synthesis, fatty acid oxidation, lead to excess fat deposition in the liver, ultimately cause abnormal glucose/lipid metabolism in male Nile tilapia. Transcriptome analyses (AGPAT2 knock-down vs. negative control) revealed a total of 5877 differentially expressed genes (DEGs). Transcriptome analyses revealed DEGs were greatly involved in some signaling pathways, such as PPAR signaling pathway, fatty acid degradation, glycolysis/gluconeogenesis, and insulin signaling pathway, which were related to lipid and glucose metabolism. We used qRT-PCR to verify the mRNA expression changes of 13 DEGs in related signaling pathways. Our results demonstrate that knock-down of elovl6 in tilapia blocks the synthesis of oleic acid and leads to abnormal glucose/lipid metabolism.
Project description:Cichlids fishes exhibit extensive phenotypic diversification and speciation. In this study we integrate transcriptomic and proteomic signatures from two cichlids species, identify novel open reading frames (nORFs) and perform evolutionary analysis on these nORF regions. We embark comparative transrcriptomics and proteogenomic analysis of two metabolically active tissues, the testes and liver, of two cichlid species Oreochromis niloticus (Nile tilapia, ON) and Pundamilia nyererei (Makobe Island, PN). Our results suggest that the time scale of speciation of the two species can be better explained by the evolutionary divergence of these nORF genomic regions.
Project description:From mammals to fish, gametogenesis and sexual maturation are driven by luteinizing hormone (LH) and follicle-stimulating hormone (FSH), the gonadotropic hormones temporally secreted from the pituitary. Teleost fish are an excellent model for addressing the unique regulation and function of each gonadotropin cell because, unlike mammals, they synthesize and secrete LH and FSH from distinct cells. Only two very distant vertebrate classes (fish and birds), demonstrate the mono-hormonal strategy suggesting a potential convergent evolution. By performing cell specific transcriptome analysis of double-labelled transgenic Nile tilapia (Oreochromis niloticus) expressing GFP and RFP in LH or FSH cells, respectively, we identified genes specifically enriched in each cell type, revealing differences in hormone regulation, receptors expression, cell signaling, and electrical properties. We found that each LH and FSH cell in fish express unique GPCR signature that reveals the direct regulation of metabolic and homeostatic hormones. Comparing these novel transcriptomes to that of rat gonadotrophs revealed conserved genes that might specifically contribute to each gonadotropin activity in mammals, suggesting conserved mechanisms controlling the differential regulation of gonadotropins in vertebrates.
2020-10-14 | GSE159470 | GEO
Project description:gut microbiota in Nile tilapia (Oreochromis niloticus)
Project description:Oreochromis niloticus represents a critically important species in the aquaculture industry due to its economic significance. Probiotics used as feed additives are known to enhance the growth performance and health of tilapia. However, the underlying mechanisms by which these benefits are conferred remain poorly understood. Here, we demonstrate that Lactobacillus salivarius exhibits significant growth performance-enhancing effects when used as a feed additive. Utilizing multi-omics approaches, our results revealed that L. salivarius significantly modulates the composition and abundance of the intestinal microbiota. Bile acids, choline, and tryptophan were identified as pivotal factors in the microbial-mediated modulation of systemic metabolism. Additionally, we have delineated a single-cell atlas of the tilapia intestine for the first time, discovering that L. salivarius_01 increases the populations of intestinal epithelial cells, immune cells, and epithelial stem cells. A broad spectrum of developmentally relevant genes and pathways were found to be activated. This study significantly advances the application of probiotics in promoting sustainable aquaculture practices.
Project description:Background: The historically recent domestication of fishes has been essential for mankind due to the overexploitation of natural stocks and the increasing protein demand to meet the needs of a growing human population. Selection for relevant traits, such as growth, during domestication is a complex process whose epigenetic basis is poorly understood. Results: We have determined changes that occur in the muscle transcriptome after a single generation of Nile tilapia (Oreochromis niloticus) domestication. There was a downregulation of 2015 genes in fish reared in captivity compared to their wild progenitors. In contrast, several myogenic and metabolic genes that can affect growth potential were upregulated. Methods: RNA was extracted and ribosomal RNA was removed using the Ribo-Zero gold rRNA removal kit. RNA libraries were prepared using the NEBNext Ultra II directional RNA library prep kit for Illumina. In total, we obtained 480 million 150 bp paired-end reads. Conclusion: Taken together, our data indicate that thousands of genes were differentially expressed within a single generation of fish domestication.
Project description:Overactive immune response is a critical factor triggering host death upon bacterial infection. However, the mechanism behind the regulation of excessive immune responses is still largely unknown, and the corresponding control and preventive measures are also to be explored. In this study, we find that the Nile tilapia, Oreochromis niloticus, died from Edwardsiella tarda infection had higher level of immune responses than those survived. Such immune responses are strongly associated with the metabolism that was altered at 6 h post-infection. By GC-MS-based metabolome profiling, we identify glycine, serine and threonine metabolism as the top three of the most impacted pathways, which were not properly activated in the fish died out of infection. Serine is one of the crucial biomarkers. Exogenous serine can promote O. niloticus survival both as prophylactic and therapeutic upon E. tarda infection. Our further analysis revealed that exogenous serine flux into the glycine, serine and threonine metabolism, and more importantly, to the glutathione metabolism via glycine. The increased glutathione synthesis could downregulate reactive oxygen species. Therefore, these data together suggest that metabolic modulation of immune responses could be a potential preventive strategy to control overactive immune responses.