Project description:A rapid decline in temperature poses a major challenge for poikilothermic fish. The gene expression of rainbow trout Oncorhynchus mykiss having undergone such a cold shock (0 °C) and a control (5 °C) were compared in a microarray-based study.
Project description:Detection of new pathways involved in the acceptance and the utilization of plant-based diet in isogenic lines of rainbow trout fry
Project description:Background: The decreasing availability of fishmeal as a protein source in aquaculture diets will require aquaculture to develop an econmoical and sustainable protien replacement. Plant proteins are readily available and are being tested as a promising alternative to replace a substantial portion of fishmeal which currently provides most of the protein content in aquaculture diets. The types of plant protein feasible for incorporation into aquaculture diets will likely contain various anti-nutritional compounds, carbohydrates, fiber, and a different amino acid profile than what is found in fishmeal. Substantial genetic variation was previously observed for growth on plant based dits in rainbow trout Hence, it will be beneficial to identify metabolic and physiologic pathways related to enhanced plant protein utilization which will aid in identifying genes that contribute to this genetic variation. Results: Microarray analysis of liver samples from two families of rainbow trout that differed in their growth responses when compared between individuals grown on a fish meal or plant protein based diet. Differential expression relating to dietary utilization between the two families found significant changes in expression of 33 ESTs. Eight of the differntially expressed ESTs had identified mammalian homologs that had been previously researched with identified cellular interactions and functions. Conclusions: Utilizing pathway analysis software to analyze sequences annotated with known mammalian genes were were ablet o map gene pathway and process interactions. From this information we were able to infer that the metabolic changes associated with utilization of plant protein versus fishmeal were associated with differential reaulation of genes related to cell oxidative stress, proliferation, growth, and survival. Furthermore, we inferred from the changes we observed in immune response genes expression that ingestion of this plant based diet upregulated the expression of genes involved in immunoregulatroy processes.
Project description:The objective of this study was to identify metabolic regulatory mechanisms affected by choline availability in rainbow trout (Oncorhynchus mykiss) broodstock diets associated with increased offspring growth performance. Three customized diets were formulated to have different levels of choline: (a) 0% choline supplementation (Low Choline: 2065 ppm choline), (b) 0.6% choline supplementation (Medium Choline: 5657 ppm choline), and (c) 1.2% choline supplementation (High Choline: 9248 ppm choline). Six all-female rainbow trout families were fed experimental diets beginning 18 months post-hatch until spawning; their offspring were fed a commercial diet. Experimental broodstock diet did not affect overall choline, fatty acid, or amino acid content in the oocytes (p > 0.05), apart from tyrosine (p ≤ 0.05). Offspring body weights from the High and Low Choline diets did not differ from those in the Medium Choline diet (p > 0.05); however, family-by-diet and sire-by-diet interactions on offspring growth were detected (p ≤ 0.05). The High Choline diet did not improve growth performance in the six broodstock families at final harvest (520-days post-hatch, or dph). Numerous genes associated with muscle development and lipid metabolism were identified, including myosin, troponin C, and fatty acid binding proteins, which were associated with key signaling pathways of lipid metabolism, muscle cell development, muscle cell proliferation, and muscle cell differentiation. These findings indicate that supplementing broodstock diets with choline does regulate expression of genes related to growth and nutrient partitioning but does not lead to growth benefits in rainbow trout families selected for disease resistance.
Project description:Transcriptional profiling of rainbow trout liver cells comparing liver cells from small fish with liver cells from large fish at two time periods.
Project description:Transcriptional profiling of rainbow trout muscle cells comparing muscle cells from small fish with muscle cells from large fish at two time periods.
Project description:The objective of this paper was to determine whether shifts in the methylome in rainbow trout (Oncorhynchus mykiss) are correlated with transcriptomic changes during early development in response to maternal dietary choline intake. Three experimental diets were formulated to have different levels of choline: (a) 2065 ppm choline (Low Choline, 0% supplementation), (b) 5657 ppm choline (Medium Choline, 0.6% supplementation), and (c) 9248 ppm choline (High Choline, 1.2% choline supplementation). Six rainbow trout families were fed experimental diets beginning 18 months post-hatch until spawning; their offspring were fed a commercial diet. Reduced representational bisulfite sequencing (RRBS) was utilized to measure genome-wide methylation differences in offspring immediately after hatching. When comparing to the Medium Choline offspring, differential DNA methylation occurred more in the Low Choline offspring than High Choline, especially in genic features like promoters. The differentially methylated CpGs (q ≤ 0.01) were identified evenly between CpG islands and shores in the genome, mostly found in the introns of genes. Genes such as fabp2 and leap2B associated with protein binding, fatty acid binding, DNA binding, and response to bacteria were differentially methylated and detected as differentially regulated genes by previous RNA-seq analysis. Although these findings indicate that levels of dietary choline available in broodstock diets alters offspring DNA methylation; most differentially expressed genes were not associated with differential DNA methylation, suggesting additional mechanisms playing a role in regulating gene expression in response to maternal choline intake.
Project description:Abstract. The molecular pathways in embryonic vertebrates leading to gonad formation in each sex are incompletely understood. The purpose of this study was to identify novel genes that could be associated with sex-specific gonadal differentiation in a fish, the rainbow trout (Oncorhynchus mykiss). This study was facilitated by a custom microarray based on 7,681 genes derived from embryonic rainbow trout gonad cDNA libraries and public databases. Gonad samples for total RNA isolation were obtained from pvasa-green fluorescent protein (pvasa-GFP) transgenic rainbow between 300 and 700 degree days of development post-fertilization. The transgenic fish permitted the collection of gonads from embryonic rainbow trout during the period of molecular sex differentiation in advance of any morphologically distinguishable characteristics of sex. A bioinformatic method was used with the microarray data that looked for strong associations in gene expression patterns between known sex differentiation genes (the target genes) and novel genes (the target-associated genes) previously not allied with sex differentiation in fishes. The expression patterns of representative targets genes from both sexes and their target-associated genes were independently confirmed by real-time reverse transcription-polymerase chain reaction to support the validity of the bioinformatics method employed. Numerous, novel genes were identified in the gonads of embryonic female and male rainbow trout that could be involved in sex-specific differentiation pathways in this fish.