Project description:Considerable interest and controversy has arisen over the potential effects of seismic surveys carried out during exploration for oil and gas deposits. Regarding fish, there is a concern that intense sound sources, such as seismic airguns, may injure their auditory system. In this study, salmonid cDNA microarrays, reciprocal suppression subtractive hybridization (SSH) cDNA libraries and quantitative reverse transcription – polymerase chain reaction (QPCR) were used to identify and study a responsive gene set in the inner ear of Atlantic salmon (Salmo salar) following seismic airgun exposure. Microarray analyses on pooled seismic exposed inner ear RNA versus pooled control inner ear RNA revealed 79 unique transcripts (passing background threshold) that were greater than 1.75-fold differentially-regulated by acoustic stress on at least 3 of the 4 slides in the study (including at least one dye-swap). QPCR analyses of 8 microarray-identified transcripts of interest revealed a significant up-regulation (P<0.05) of transcripts encoding nicotinamide riboside kinase 2 (1.89-fold) and hemoglobin subunit alpha-4 (3.78-fold), and a significant down-regulation (P<0.05) of a transcript encoding C14orf159 protein (1.35-fold). QPCR analyses also confirmed an overall up-regulation of transcripts encoding growth hormone I (7.78-fold), c-type lectin receptor A (2.20-fold) and retinol binding protein I (1.24-fold), however these differences were not considered to be statistically significant (P<0.05) due to the high biological variability in the seismic exposed group for these transcripts of interest. A total of 683 expressed sequence tags (ESTs) generated from SSH cDNA salmon ear libraries enriched for genes responsive to seismic airgun noise have been deposited in the GenBank dbEST. Targeted gene discovery in salmon ear allowed for the identification of novel transcripts, including some with sensory-relevant functional annotations, and represents a significant contribution to salmonid hearing research. Initial results demonstrate that genomics has the potential to greatly enhance our understanding of the impact of seismic airguns on gene and molecular pathways involved in hearing, and provide valuable molecular biomarkers that can act as an early warning sensor to acoustic stress. Juvenile Atlantic salmon (Salmo salar) smolt were obtained from North Water Products Ltd., Daniel’s Harbour, NL and held at ambient seawater temperature, in a flow-through system supplied with air at the Northwest Atlantic Fisheries Centre, St. John’s, NL. Two weeks prior to seismic airgun exposures, fish were divided into two 1m3 cages, one each for control (non-exposed) and exposed groups, in a 15,000L aquarium at ambient seawater temperature (0.2°C). Each cage was placed the same distance from the water intake and airstones were placed next to each cage. Fish were fasted for two days prior to exposure. Sixteen control (non-exposed) fish from one cage were sampled prior to seismic activity. Immediately following sampling of control fish, seventeen fish in the remaining cage were placed 2m from a 10in3 Texas Instruments airgun. Fish were subjected to 50 exposures, 1 exposure every 10 seconds, at an average sound pressure level of 204 dB peak-to-peak relative to 1µPa; considered to be a worse case scenario within a few hundred meters of a survey vessel. Seventeen seismic exposed fish were sampled 16 h following exposure. The only aquarium available that was suitable for seismic airgun exposures was not designed to have a regulated photoperiod. For this reason the fish were held under a constant daylight regime. Fish were collected by dip-net and euthanized by severing the spinal cord. The inner ears from each salmon were removed, placed immediately in RNase-free 2 ml tubes, and then flash frozen in liquid nitrogen. RNA isolated from the right inner ear of the 12 seismic exposed and 12 control individuals that gave the highest total RNA yields were used to generate 2 mRNA pools (a “seismic” pool and a “control” pool). Each sample contributed 4.0 µg column purified total RNA to each pool. Comparisons were made for the seismic exposed mRNA pool compared to the control (non-exposed) mRNA pool using the consortium for Genomic Research on All Salmonids Project (cGRASP) 16K (salmonid) cDNA array and the 3DNA Array 900 Detection Kit and instructions (Genisphere). Technical quadruplicate slides including 2 dye-swaps were run for the comparison. Slide GG003_011: Cy5-labeled control ear, Cy3-labeled seismic Slide GG003_012: Cy5-labeled control ear, Cy3-labeled seismic Slide GG003_013: Cy3-labeled control ear, Cy5-labeled seismic Slide GG003_014: Cy3-labeled control ear, Cy5-labeled seismic
Project description:Considerable interest and controversy has arisen over the potential effects of seismic surveys carried out during exploration for oil and gas deposits. Regarding fish, there is a concern that intense sound sources, such as seismic airguns, may injure their auditory system. In this study, salmonid cDNA microarrays and quantitative reverse transcription – polymerase chain reaction (QPCR) were used to identify and study a responsive gene set in the inner ear of Atlantic salmon (Salmo salar) following seismic airgun exposure. Microarray analyses on pooled seismic exposed inner ear RNA versus pooled control inner ear RNA revealed 79 unique transcripts (passing background threshold) that were greater than 1.75-fold differentially-regulated by acoustic stress on at least 3 of the 4 slides in the study (including at least one dye-swap). QPCR analyses of 8 microarray-identified transcripts of interest revealed a significant up-regulation (P<0.05) of transcripts encoding nicotinamide riboside kinase 2 (1.89-fold) and hemoglobin subunit alpha-4 (3.78-fold), and a significant down-regulation (P<0.05) of a transcript encoding C14orf159 protein (1.35-fold). QPCR analyses also confirmed an overall up-regulation of transcripts encoding growth hormone I (7.78-fold), c-type lectin receptor A (2.20-fold) and retinol binding protein I (1.24-fold), however these differences were not considered to be statistically significant (P<0.05) due to the high biological variability in the seismic exposed group for these transcripts of interest. Initial results demonstrate that genomics has the potential to greatly enhance our understanding of the impact of seismic airguns on gene and molecular pathways involved in hearing, and provide valuable molecular biomarkers that can act as an early warning sensor to acoustic stress.
Project description:Norway is the largest producer and exporter of farmed Atlantic salmon (Salmo salar) worldwide. Skin disorders correlated with bacterial infections represent an important challenge for fish farmers due to the economic losses caused. Little is known about this topic, thus studying the skin-mucus of Salmo salar and its bacterial community depict a step forward in understanding fish welfare in aquaculture. In this study, we used label free quantitative mass spectrometry to investigate the skin-mucus proteins associated with both Atlantic salmon and bacteria. In addition, the microbial temporal proteome dynamics during 9 days of mucus incubation with sterilized seawater was investigated, in order to evaluate their capacity to utilize mucus components for growth in this environment.
Project description:The present study aimed to identify the persistent molecular changes occurring in Atlantic Salmon salmon (Salmo salar) eggs after 24h exposure to high concentrations (5000 mg/L) of road salt at fertilization.
Project description:The present study aimed to identify the persistent molecular changes occurring in Atlantic Salmon salmon (Salmo salar) eggs after 24h exposure to high concentrations (5000 mg/L) of road salt at fertilization. Atlantic Salmon (Salmo salar) eggs after fertilization were exposed to high concentrations (5000 mg/L) of road salt for 24 h and used for gene expression analysis.
Project description:Atlantic salmon (Salmo salar L.) is an environmentally and economically important organism and its gene content is reasonably well characterized. From a transcriptional standpoint, it is important to characterize the normal changes in gene expression over the course of early development, from fertilization through to the parr stage.S. salar samples were taken at 17 time points from 2 to 89 days post fertilization. Total RNA was extracted and cRNA was synthesized and hybridized to a new 44K oligo salmonid microarray platform. Quantified results were subjected to preliminary data analysis and submitted to NCBI’s Gene Expression Omnibus. Throughout the entire period of development, several thousand genes were found to be differentially regulated. This work represents the trancriptional characterization of a very large geneset that will be extremely valuable in further examination of the transcriptional changes in Atlantic salmon during the first few months of development. The expression profiles can help to annotate salmon genes in addition to being used as references against any number of experimental variables that developing salmonids might be subjected to.
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:An effective and economical vaccine against the Piscirickettsia salmonis pathogen is needed for sustainable salmon farming and to reduce disease-related economic losses. Consequently, the aquaculture industry urgently needs to investigate efficient prophylactic measures. Three protein-based vaccine prototypes against Piscirickettsia salmonis were prepared from a highly pathogenic Chilean isolate. Only one vaccine effectively protected Atlantic salmon (Salmo salar), in correlation with the induction of Piscirickettsia-specific IgM antibodies and a high induction of transcripts encoding pro-inflammatory cytokines (i.e. Il-1β and TNF-α). In addition, we studied the proteome fraction protein of P. salmonis strain Austral-005 using multidimensional protein identification technology. The analyzes identified 87 proteins of different subcellular origins, such as the cytoplasmic and membrane compartment, where many of them have virulence functions. The other two prototypes activated only the innate immune responses, but did not protect Salmo salar against Piscirickettsia salmonis. These results suggest that the knowledge of the formulation of vaccines based on P. salmonis proteins is useful as an effective therapy, this demonstrates the importance of the different research tools to improve the study of the different immune responses, resistance to diseases in the Atlantic salmon. We suggest that this vaccine can help prevent widespread infection by P. salmonis, in addition to being able to be used as a booster after a primary vaccine to maintain high levels of circulating protective antibodies, greatly helping to reduce the economic losses caused by the pathogen.
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.