Project description:We report here the release of a multi organ transcriptome developped for the Arctic char Salvelinus alpinus. This reference set was obtained using the 454 GS FLX+ technology. A pool of one-year-old, immature offspring of wild, anadromous Arctic charr originating from Lake Varflusjoen, Svalbard (79oN), including both lean and fat individuals, and three-years-old mature offspring of charr originating from Lake Vårflusjøen, North-Norway (70oN) was sampled. In order to maximize the diversity of expressed transcripts, we sampled a variety of organs and tissues; the whole brain, gill and head kidney and pieces of the liver, gonad, abdominal fat and muscle.
Project description:We investigated whether two sympatric Arctic charr morphs (Salvelinus alpinus) with contrasting feeding ecology, the small-benthic (SB) and the planktivorous (PL) charr of Thingvallavatn in Iceland, exhibit genetically based differences in gene expression variability, and how dominance would affect their hybrids. Through a common-garden experiment, we identified genes clusters with similar expression variability, most differing among the two morphs. In the hybrids, gene expression variability was substantially affected by maternal effects and biases towards the PL charr, while the expression of a minority of genes felt outside the range of parental values. These profiles of expression variability were consistent across mRNA and miRNA datasets. Predominant maternal effects and PL charr biases were also observed at the level of average gene expression, including candidate genes involved in the lower jaw development.
2023-01-01 | GSE193797 | GEO
Project description:RNA sequencing of Arctic charr (Salvelinus alpinus)
Project description:The aim of this sequencing experiment was to make available liver tissue expression for selected fish species, northern pike (Esox lucius, Eluc), coho salmon (Oncorhynchus kisutch, Okis) and Arctic charr (Salvelinus alpinus, Salp), for comparative expression studies between the species. Samples in replicate of four were sacrificed according to protocols at each of the facilities from where samples were obtained. RNA was extracted from samples and Illumina TruSeq Stranded mRNA libraries were built. Sequencing was performed in two passes on an Illumina HiSeq2500, paired-end 125bp reads. Processed count tables per species as raw counts, FPKM, or TPM, were generated from read alignment to the NCBI genomes of the respective species using STAR and gene level counting using RSEM and NCBI gene annotation.
Project description:Arctic charr is an especially attractive aquaculture species given that it features the desirable tissue traits of other salmonids, but can be bred and grown at inland freshwater tank farms year round. It is therefore of interest to develop upper temperature tolerant (UTT) strains of Arctic charr to increase the robustness of the species in the face of climate change, as well as to enable production in more southern regions. We conducted an acute temperature trial to identify temperature tolerant and intolerant Arctic charr individuals. Specifically, approximately 200 fish were transferred to an experimental tank (diameter: 1.86 m, depth 50 cm) and left to acclimate for 48 h at ambient temperature. After acclimation, 10 fish were removed to act as a control group, then water that had been diverted through a heat exchanger was added to the flow-through system to increase the water temperature in the tank by 6°C/h until it reached 22°C, then 0.5°C every 30 min until the water reached 25°C, the observed lethal temperature for these fish. When the water temperature reached 25°C, the temperature was held constant and the fish were closely monitored for signs of stress. The first and last 10 individuals to show loss of balance were quickly removed from the tank for sampling, thus representing the 5% least and most temperature tolerant fish, respectively. A reference design microarray study was then performed with the cGRASP 32K microarray using six samples from each group (Intolerant, Tolerant, Control) to identify genes differentially expressed between groups. The results of this study will feed into an ongoing Arctic charr marker-assisted selection based broodstock development program, and may contribute to population-based conservation initiatives for salmonids in general.