Project description:Rainbow trout (Oncorhynchus mykiss) is an important aquaculture fish species that is farmed worldwide, and it is also the most widely cultivated cold water fish in China. This species, a member of the salmonidae family, is an ideal model organism for studying the immune system in fish. Two phenotypes of rainbow trout are widely cultured; wild-type rainbow trout with black skin (WR_S) and yellow mutant rainbow trout with yellow skin (YR_S). Fish skin is an important immune organ, however, little is known about the differences in skin immunity between WR_S and YR_S in a natural flowing water pond aquaculture environment, and very few studies were conducted to investigate the ceRNA mechanism for fish skin.
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:Transcriptional responses to hypoxia were compared between a hypoxia tolerant fish (tidepool sculpin; Oligocottus maculosus) and a hypoxia intolerant fish (silverspotted sculpin; Blepsias cirrhosus). To determine if, and how, transcriptional plasticity is associated with differences in hypoxia tolerance, each species was subjected to a hypoxic time-course and liver was sampled at normoxia, 3hr, 8hr, 24hr, 48hr and 72hr of hypoxia. The hypoxic level for each species was scaled to the species' own tolerance level (relative exposure) in order to elicit similar tissue level hypoxia between the two sculpin species. Each species was also subjected to a single environmental O2 tension (absolute exposure) and sampled at 24 hrs of hypoxia.
Project description:The goal of this study was to measure the effect of heat stress on the transcriptome of a cold-adapted fish species - Trematomus bernacchii - an Antarctic fish species. Keywords: Stress response
Project description:Streptococcus pneumoniae (S. pneumoniae) is a major human pathogen causing morbidity and mortality worldwide. Efficiently acquiring iron from the environment is critical for S. pneumoniae to sustain growth and cause infection. There are only three known iron-uptake systems in Streptococcal species responsible for iron acquisition from the host, including ABC transporters PiaABC, PiuABC and PitABC. Besides, no other iron-transporting system has been suggested. In this work, we employed our newly established translating mRNA analysis integrated with proteomics to evaluate the possible existence of novel iron transporters in the bacterium. We simultaneously deleted the iron-binding protein genes of the three iron-uptake systems to construct a piaA/piuA/pitA triple mutant (Tri-Mut) of S. pneumoniae D39, in which genes and proteins related to iron transport should be regulated in response to the deletion. With ribosome associated mRNA sequencing-based translatomics focusing on translating mRNA and iTRAQ quantitative proteomics based on the covalent labeling of peptides with tags of varying mass, we indeed observed a large number of genes and proteins representing various coordinated biological pathways with significantly altered expression levels in the Tri-Mut mutant. Highlighted in this observation is the identification of several new potential iron-uptake ABC transporters for Streptococcal iron metabolism. In particular, putative protein SPD_1609 in operon 804 was verified to be a novel iron-binding protein with similar function to PitA in S. pneumoniae. These data derived from the integrative translatomics and proteomics analyses provided rich information and insightful clues for further investigations on iron-transporting mechanism in bacteria and the interplay between Streptococcal iron availability and the biological metabolic pathways.