Project description:LC-MS/MS proteomics was used to identify immune proteins in the plasma of the nurse shark (Ginglymostoma cirratum), using a de novo multi-tissue transcriptome generated for this species. LC-MS/MS was then used to assess the host response to immunization with human serum albumin (HSA) and Complete Freund’s Adjuvant (CFA).
Project description:Background Methylation of CG dinucleotides constitutes a critical system of epigenetic memory in bony vertebrates, where it modulates gene expression and suppresses transposon activity. The genomes of studied vertebrates are pervasively hypermethylated, with the exception of regulatory elements such as transcription start sites (TSSs), where the presence of methylation is associated with gene silencing. This system is not found in the sparsely methylated genomes of invertebrates, and establishing how it arose during early vertebrate evolution is impeded by a paucity of epigenetic data from basal vertebrates. Methods We perform whole-genome bisulfite sequencing to generate the first genome-wide methylation profiles of a cartilaginous fish, the elephant shark Callorhinchus milii. Employing these to determine the elephant shark methylome structure and its relationship with expression, we compare this with higher vertebrates and an invertebrate chordate using published methylation and transcriptome data. Results Like higher vertebrates, the majority of elephant shark CG sites are highly methylated, and methylation is abundant across the genome rather than patterned in the mosaic configuration of invertebrates. This global hypermethylation includes transposable elements and the bodies of genes at all expression levels. Significantly, we document an inverse relationship between TSS methylation and expression in the elephant shark, supporting the presence of the repressive regulatory architecture shared by higher vertebrates. Conclusions Our demonstration that methylation patterns in a cartilaginous fish are characteristic of higher vertebrates imply the conservation of this epigenetic modification system across jawed vertebrates separated by 465 million years of evolution. In addition, these findings position the elephant shark as a valuable model to explore the evolutionary history and function of vertebrate methylation.
Project description:Replacement of high-value fish species with cheaper varieties or mislabelling of food unfit for human consumption is a global problem violating both consumers’ rights and safety. For distinguishing fish species in pure samples, DNA approaches are available; however, authentication and quantification of fish species in mixtures remains a challenge. In the present study, a novel high-throughput shotgun DNA sequencing approach applying masked reference libraries was developed and used for authentication and abundance calculations of fish species in mixed samples. Results demonstrate that the analytical protocol presented here can discriminate and predict relative abundances of different fish species in mixed samples with high accuracy. In addition to DNA analyses, shotgun proteomics tools based on direct spectra comparisons were employed on the same mixture. Similar to the DNA approach, the identification of individual fish species and the estimation of their respective relative abundances in a mixed sample also were feasible. Furthermore, the data obtained indicated that DNA sequencing using masked libraries predicted species-composition of the fish mixture with higher specificity, while at a taxonomic family level, relative abundances of the different species in the fish mixture were predicted with slightly higher accuracy using proteomics tools. Taken together, the results demonstrate that both DNA and protein-based approaches presented here can be used to efficiently tackle current challenges in feed and food authentication analyses.
Project description:Mandarin fish Siniperca chuatsi (Basilewsky) (Percichthyidae), as a demersal piscivore, has very specialized feeding habits, for as soon as they start feeding the fry of this fish feed solely on fry of other fish species. In rearing conditions, mandarin fish has been found to accept live prey fish only, and refuse dead prey fish or artificial diets, very little is currently known about the molecular mechanisms of multiple genes which cover different pathways influencing the specialized food habit, such as live prey. We performed transcriptome comparisons between dead prey fish feeders and nonfeeders in mandarin fish. The determination mechanisms of specialized food habit (live prey fish) in mandarin fish could provide some instructions for research of food habit in animals, including mammals.
Project description:RATIONALE: Shark cartilage extract may help shrink or slow the growth of colorectal cancer or breast cancer cells.
PURPOSE: Randomized phase III trial to determine the effectiveness of shark cartilage in treating patients who have advanced colorectal cancer or advanced breast cancer.