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. 18 microarray slides representing 6 individuals from 3 treatment groups (Intolerant, Tolerant and Control). One test cDNA labeled with cy5 and the common reference aRNA labeled with Cy3 was hybridized to each slide Reference design: 18 slides (6 x Tolerant fish, 6x Intolerant fish, 6x Control fish) were used.
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.
Project description:In this study we used Illumina RNA-seq to identify genes expressed by A. veronii in mid-log phase growth in a rich medium and within the digestive tract of the medicinal leech. Our results shed light on the physiology of A. veronii during colonization of the leech gut.
Project description:In this study we used Illumina RNA-seq to identify genes expressed by A. veronii in mid-log phase growth in a rich medium and within the digestive tract of the medicinal leech. Our results shed light on the physiology of A. veronii during colonization of the leech gut. A comparison of Illumina RNA-seq of A. veronii in vivo versus in vitro.
Project description:Polar cod, a key fish species in the arctic marine foodweb is vulnerable to effects of pollution from offshore petroleum related activities in the Arctic and sub-arctic region. The study was conducted to map transcriptome responses to in Polar cod (Boreogadus saida) liver slice culture exposed to benzo[a]pyrene (BaP) in the presence or absence of physiological levels of ethynylestradiol (EE2). BaP is a polycyclic aromatic hydrocarbon (PAH), also found in crude oil contaminants. PAHs such as BaP are among the most toxic compounds of crude oil. Precision-cut liver slice cultures from five female polar cod (n = 5/ group, paired design) were exposed to BaP alone (10 µM), or in combination with low concentrations of EE2 (5 nM), to mimic physiological estradiol levels in early vitellogenic female fish. Transcriptome analysis (RNA-seq) was performed after 72 h exposure in culture. The results provide a global view of transcriptome responses to BaP, EE2 and their mixture. In the mixture exposure, BaP resulted attenuation of EE2 stimulated gene expression (anti-estrogenic effects). The results from this ex vivo experiment suggest that pollutants that activate the Ahr pathway such as the PAH compound BaP can result in anti-estrogenic effects that may lead to endocrine disruption in polar cod.
Project description:Arctic charr thrive at high densities and can live in freshwater year round, making this species especially suitable for inland, closed containment aquaculture. However, it is a cold water salmonid, which both limits where the species can be farmed and places wild populations at particular risk to climate change. Previously, we identified genes associated with tolerance and intolerance to acute, lethal temperature stress in Arctic charr. However, there remained a need to examine the genes involved in the stress response to more realistic temperatures that could be experienced during a summer heat wave in grow-out tanks that are not artificially cooled, or under natural conditions. Here, we exposed Arctic charr to moderate heat stress of 15–18ºC for 72 hours, and gill tissues extracted before, during (i.e., at 72 hrs), immediately after cooling and after 72 hours of recovery at ambient temperature (6ºC) were used for gene expression profiling by microarray and qPCR analyses. The results revealed an expected pattern for heat shock protein (Hsp) expression, which was highest during heat exposure, with significantly reduced expression (approaching control levels) quickly thereafter. We also found that the expression of numerous ribosomal proteins was significantly elevated immediately and 72 hrs after cooling, suggesting that the gill tissues were undergoing ribosomal biogenesis while recovering from damage caused by heat stress. We suggest that these are candidate gene targets for the future development of genetic markers for broodstock development or for monitoring temperature stress and recovery in wild or cultured conditions. 24 microarray slides representing 6 individuals from 4 treatment groups (Control, During, After and Recovery). One test cDNA labeled with Cy5 and the common reference aRNA labeled with Cy3 was hybridized to each slide. Reference design: 6x control fish, 6x group D fish, 6x group A fish, 6x group R fish.
Project description:Long rough dab (Hippoglossoides platessoides) is an important flatfish fish species in the north Atlantic arctic and sub-arctic marine foodweb that could be vulnerable to contaminant exposure from offshore petroleum related activities. The study was conducted to map transcriptome responses in long rough dab precision cut liver slice (PCLS) culture exposed to benzo[a]pyrene (BaP). BaP is a polyaromatic hydrocarbon (PAH) which is among the most toxic compounds found in crude oil. PCLS culture was performed under 10 µM BaP exposure for 72 h and transcriptome analysis (RNA-seq) analysis was performed to characterize de novo transcriptome of the liver and identify genes responding to BaP exposure.