Project description:Exposure to environmental contaminants like nonylphenol can disrupt smolt development and may be a contributing factor in salmon population declines. We used GRASP 16K cDNA microarrays to identify genes that are differentially expressed in the liver, gill, hypothalamus, pituitary, and olfactory rosettes of Atlantic salmon smolts treated with nonylphenol compared to control smolts. Nonylphenol treatment was confirmed using physiological assays: nonylphenol-treatment significantly decreased gill Na+,K+-ATPase activity and plasma cortisol and T3 levels.
Project description:Deciphering the dietary immunomodulatory effects of a feed additive rich in triterpenic compounds and polyphenols (AQUOLIVE®, NATAC Biotech SL, Spain) on the systemic immune response and disease resistance of Atlantic salmon (Salmo salar L.) smolts.
Project description:Deciphering the dietary immunomodulatory effects of a feed additive rich in verbascoside and triterpenic compounds like ursolic (MPLE, NATAC Biotech SL, Spain) on the systemic immune response and disease resistance of Atlantic salmon (Salmo salar L.) smolts.
Project description:We investigate the effect of a functional feed for immunostimulation (peptidoglycan extract from bacterial cell wall with nucleotide formulation) on L. salmonis infection levels on Atlantic salmon Salmo salar, and on host and parasite gene expression profiles. Atlantic salmon smolts (~95 g) were fed a control diet, or a low or high dose immunostimulant diet, and then exposed to L. salmonis copepodids in three subsequent exposures. The transcriptome of salmon lice late in the infection attached to either the low dose diet or control diet hosts were compared using a 38K oligonucleotide microarray.
Project description:To identify genes involved in the developmental process of Atlantic salmon smoltification, gene expression was compared between smolt and parr in tissues involved in osmoregulation (gill), metabolism (liver), imprinting (olfactory rosettes) and neuroendocrine control (hypothalamus and pituitary). Tissue samples were harvested from laboratory-reared parr and smolts on the same date. Smolts were distinguished from parr by size and appearance; developmental status was confirmed by physiological assays.
Project description:The effect of different diets (i.e. fish oil based vs vegetable oil based) on liver transcription profiles over the life history stages (freshwater and marine phases) of cultured Atlantic salmon (Salmo salar) were explored. Two groups of fish were raised from first feeding on different lipid containing diets; a) the standard 100% fish oil based diet, the other enriched with a blend of vegetable oils (75%) + fish oil (25%). Liver samples were taken from fish at four time points: two freshwater phase (as parr 36 weeks post hatch (wph); as pre-smolts, 52 wph) and two marine phase ( as post-smolts 55 wph; and as adult fish , 86 wph). A total of 96 cDNA microarray hybridisations - TRAITS / SGP Atlantic salmon 17k feature cDNA microarray - were performed ( 2 diets x 4 time points x 6 biological replicates x 2 -dye swap) using a comon pooled reference contol design.
Project description:The salmon louse is an ectoparasitic copepod that causes major economic losses in the aquaculture industry of Atlantic salmon. This host displays a high level of susceptibility to lice which can be accounted for by several factors including stress. In addition, the parasite itself acts as a potent stressor of the host, and outcomes of infection can depend on biotic and abiotic factors that stimulate production of cortisol. Consequently, examination of responses to infection with this parasite, in addition to stress hormone regulation in Atlantic salmon, is vital for better understanding of the host pathogen interaction. Atlantic salmon post smolts were exposed to stress hormone cortisol, lice and their combination. The transcriptomic effects of hormone treatment in salmon skin were significantly greater than lice-infection induced changes. Cortisol stimulated expression of genes involved in metabolism of steroids and amino acids, chaperones, responses to oxidative stress and eicosanoid metabolism and suppressed genes related to antigen presentation, B and T cells, antiviral and inflammatory responses. Cortisol and liceBoth treatments equally down-regulated a large panel of motor proteins that can be important for wound contraction. Cortisol also suppressed multiple genes involved in wound healing, parts of which were activated by the parasite. Down-regulation of collagens and other structural proteins was in parallel with the induction of proteinases that degrade extracellular matrix (MMP9 and MMP13). Cortisol reduced expression of genes encoding proteins involved in formation of various tissue structures, regulators of cell differentiation and growth factors. Atlantic salmon post smolts were organised into four experimental groups: lice + cortisol, lice + placebo, no lice + cortisol, no lice + placebo. Infection levels were equal in both treatments upon termination of the experiment. Gene expression changes in skin were assessed with 21 k oligonucleotide microarray and qPCR at the chalimus stage 18 days post infection at 9oC.
Project description:To identify genes involved in the developmental process of Atlantic salmon smoltification, gene expression was compared between smolt and parr in tissues involved in osmoregulation (gill), metabolism (liver), imprinting (olfactory rosettes) and neuroendocrine control (hypothalamus and pituitary). Tissue samples were harvested from laboratory-reared parr and smolts on the same date. Smolts were distinguished from parr by size and appearance; developmental status was confirmed by physiological assays. Eight biological replicates (16 fish) balanced for sex and for dye were used in the liver, gill, olfactory rosette, and hypothalamus comparisons. Four male parr were compared to four male smolts and four female parr were compared to four female smolts; smolts were labeled with Alexa Fluor 555 on four arrays and with Alexa Fluor 647 on four arrays. Six biological replicates (12 fish) were used for the pituitary comparison (two female and four male).
Project description:Unintentional use of mold-infested plant-based feed ingredients are sources of mycotoxins in fish feeds. The presence of the emerging mycotoxins ENNB and BEA in Norwegian commercial fish feeds and plant-based feed ingredients has raised concerns regarding the health effects on farmed Atlantic salmon (Salmon salar). Atlantic salmon pre-smolts were exposed to a non-lethal single-dose of BEA and ENNB, and total RNA sequencing of the intestine and liver was carried out to evaluate gut health and identify possible hepatological changes after a single-dose dietary exposure. ENNB and BEA did not give acute toxicity, however ENNB caused the onset of pathways linked to acute intestinal inflammation and BEA exposures caused the onset of hepatic hematological disruption. The prevalence and concentration of ENNB found in today's commercial feed could affect the fish health if consumed over a longer time-period.