Project description:Amoebic gill disease (AGD) is an ectoparasitic condition of some farm-reared marine fish and is caused by Neoparamoeba perurans. Tanks housing Atlantic salmon (Salmo salar) were inoculated with Neoparamoeba perurans and fish were sampled at 36 days postinoculation (pi.). AGD-affected gill tissue was dissected from N. perurans infected fish, and a DNA microarray was used to compare global gene expression against tissues from AGD-naive fish. To determine whether the changes in gene expression were restricted to AGD-lesions, lesion tissue from AGD-affected fish was also compared with non-lesion gill tissue dissected from the same gill arch. Samples were assessed using a DNA microarray. Keywords: comparative gene expression, parasite-induced lesion, Neoparamoeba perurans, amoebic gill disease
Project description:RNA sequencing was used to measure global gene expression in wild caught threespine sticklebacks. Native freshwater and marine fish were acclimated in water of different salinities before the gene expression in kidney was measured. The comparative transcriptomic analysis allowed the identification of salt-responsive genes.
Project description:Amoebic gill disease (AGD) is an ectoparasitic condition of some farm-reared marine fish and is caused by Neoparamoeba perurans. Tanks housing Atlantic salmon (Salmo salar) were inoculated with Neoparamoeba perurans and fish were sampled at 36 days postinoculation (pi.). AGD-affected gill tissue was dissected from N. perurans infected fish, and a DNA microarray was used to compare global gene expression against tissues from AGD-naive fish. To determine whether the changes in gene expression were restricted to AGD-lesions, lesion tissue from AGD-affected fish was also compared with non-lesion gill tissue dissected from the same gill arch. Samples were assessed using a DNA microarray. mRNA from lesion and non-lesion gill tissue was amplified and labeled. Six biological and two technical replicates were utilised to hybridise to 12 arrays using amplified RNA from AGD-affected lesion gill tissue with AGD-naive fish as a control. Four biological and two technical replicates were utilised to hybridise to 8 arrays using amplified RNA from AGD-affected lesion gill tissue with non-lesion tissue from the same gill arch as a control. The assignment of microarrays to treatment groups for hybridization was randomised by using a random number generator.
Project description:The marine teleost intestine plays a vital role in whole body salt and water homeostasis. Marine fish must drink seawater in order to rehydrate, and processing of that seawater throughout the gastrointestinal tract allows for the extraction of water from this highly hyperosmotic source. Although the molecular mechanisms of this process have been the subject of much investigation, numerous questions remain. Here, Gulf toadfish (Opsanus beta) were acclimated to normal seawater (35 ppt) of hypersaline seawater (60 ppt) and changes in the anterior intestine, posterior intestine, and intestinal fluid proteomes were investigated using a shotgun proteomics approach employing isobaric TMT tags.
Project description:Oil spills have polluted the marine environment for decades and continue to be a major source of polycyclic aromatic hydrocarbons (PAHs) to marine ecosystems around the globe. Although the toxicity of PAHs to fish has been well studied, the combined effects of extreme abiotic factors and oil are poorly understood. Gulf of Mexico killifish Fundulus grandis larvae (< 24 hours post hatch) were exposed to varying environmental conditions (dissolved oxygen 2, 6 ppm; temperature 20, 25, 30°C; and salinity 3, 10, 30 ppt) combined with varying concentrations of high energy water accommodated fractions (HEWAF) (total PAHs 0 – ~ 125 ppb) for a total of 48 h. Larvae survival and development were negatively affected by PAHs, starting with the lowest concentration tested (~15 ppb). High temperature + hypoxia + PAHs resulted in the lowest survival with salinity having little impact on any of the endpoints tested. Expression of the hepatic detoxifying gene cyp1a was highly induced in PAH-exposed larvae, but only under normoxic conditions. A lack of cyp1a induction under hypoxia and PAH exposure could explain the enhanced toxicity observed. This work highlights the need for more studies examining the combined impact of suboptimal water quality parameters in the presence of pollution in fish early life-stages.
Project description:Brain transcriptome at 0h, 1h, 3h, 6h, 12h, 24h, 48h after hypoxia stress Large yellow croakers (body weight at 90-100 g) were purchased from the mariculture farm in Ningde, Fuzhou, China. The fish were maintained at 25 °C in aerated water tanks (dissolved oxygen concentration: 7.8±0.5 mg per liter) with a flow through seawater supply. After 7 days of acclimation, these fish were used for the following experiments. Hypoxic time-course experiments were conducted at 25 °C using published method 30, by bubbling nitrogen gas into an aquarium. The desired pO2 was controlled by using dissolved oxygen meter (, Canada). At the onset of the time course, the oxygen content of the tank was lowered from an aerated pO2 of 100% (7.8 mg per liter) down to 20% (1.6±0.2 mg per liter) over a 30-min period. At the 1-, 3-, 6-, 12-, 24-, and 48-h time points, fish were sampled and sequenced.
Project description:Circulating plasma microRNAs (miRNAs) are well established as biomarkers of several diseases in humans and have recently been used as indicators of environmental exposures in fish. However, the role of plasma miRNAs in regulating acute stress responses in fish is largely unknown. Tissue and plasma miRNAs have recently been associated with excreted miRNAs in humans however external miRNAs have never been measured in fish. The objective of this study was to characterize the plasma miRNA profile in response to acute stress in rainbow trout (Oncorhynchus mykiss), as well as miRNA profiles in novel external samples, (fish epidermal mucus and the surrounding water). RNA was extracted and sequenced from plasma, mucus, and water collected from rainbow trout and their surrounding environment prior to and one-hour following a three-minute air exposure, a known inducer of an acute stress response in fish. Following small RNA-Seq and pathway analysis, we identified differentially expressed plasma miRNAs that targeted biosynthetic, degradation, and metabolic pathways. We successfully isolated miRNA from trout mucus and the surrounding water and detected differences in miRNA expression one-hour post air stress. The altered miRNA profiles in mucus and water were unique to the altered plasma miRNA profile, indicating that the plasma miRNA response was not associated with or immediately reflected in external samples. This research expands our understanding of the role of plasma miRNA in the acute stress response of fish and is the first study to report on the successful isolation and profiling of miRNA from fish mucus and water samples. Measurements of miRNA from plasma, mucus, and water can be further studied and have the potential to be applied in environmental monitoring as non-lethal indicators of acute stress in fish.