Project description:This study investigates transcriptomic responses of Atlantic salmon lice, Lepeophtheirus salmonis exposed to cypermethrin, a commonly used antiparasitic agent used in aquaculture. Copepodid L. salmonis were exposed to cypermethrin (Betamax®) at a concentration of 1.0ppb
Project description:This study investigates sex-biased gene expression between populations of Atlantic and Pacific salmon lice, Lepeophtheirus salmonis. Two Atlantic L. salmonis populations were previously used for an array study (GSE56024) while a third dataset using Pacific L. salmonis was novel. Using all three populations, a consensus-based, meta-analysis approach was used to identify sex-biased and sex-specific genes.
Project description:This study investigates transcriptomic responses of Pacific salmon lice, Lepeophtheirus salmonis, to infection with the microsporidian Facilispora margolisi and/or exposure to emamectin benzoate (EMB), an antiparasitic agent commonly used in salmon aquaculture.
Project description:This study investigates the baseline or inducible differences in between populations of Atlantic salmon lice Lepeophtheirus salmonis with differing levels of resistance to the parasiticidal drug emamectin benzoate (EMB), as well as the induced effects of EMB exposure to Pacific salmon lice. F1 generation lice were exposed in bioassays to a dilution series of emamectin benzoate.
Project description:This study investigates transcriptomic responses of Atlantic salmon lice, Lepeophtheirus salmonis exposed to cypermethrin, a commonly used antiparasitic agent used in aquaculture. Copepodid L. salmonis were exposed to cypermethrin (Betamax®) at a concentration of 1.0ppb An in vitro bioassay experiment was conducted using cypermethrin exposures on copepodid (larvae) sea lice (F1 generation) collected from BMA-2a New Brunswick, Canada in 2014. The bioassay exposed copepodids to 1.0 μg/L cypermethrin or a sea water control for 24 hours in glass beakers (VWR) at 12 ± 1oC. Each condition had a total volume of 500mL with six replicates and approximately 500 lice per beaker. After 24 hours, pools of ~500 copepodids were flash frozen for RNA extractions. Post 24-hours, lice were assessed for survival similarly to the technique used for staging and enumeratio first
Project description:This study investigates host-specific gene expression of the Pacific salmon lice, Lepeophtheirus salmonis oncorhynchii, while parasitizing a resistant host (Coho salmon), two susceptible hosts (Atlantic salmon, Sockeye salmon), and a population with-held hosts (starved), over 48 hrs.
Project description:This study investigates sex-biased gene expression between populations of Atlantic and Pacific salmon lice, Lepeophtheirus salmonis. Two Atlantic L. salmonis populations were previously used for an array study (GSE56024) while a third dataset using Pacific L. salmonis was novel. Using all three populations, a consensus-based, meta-analysis approach was used to identify sex-biased and sex-specific genes. Two separate experiments were conducted, one for Atlantic and one for Pacific salmon lice. As the Atlantic data has been previously published for other comparisons (GSE56024), only the Pacific data is uploaded here. Lice from three populations (2 in the Atlantic and 1 in the Pacific) were collected for in vitro bioassay analysis using emamectin benzoate. After 24hrs, lice were collected as per treatment protocol below. Males and females from all populations were compared separately before forming a consensus probe list of sex-biased genes concordantly expressed across all three populations. Please note that each raw data file contains three or four 'block' data and each block data correspond to individual sample raw data. Therefore, each raw data file contains raw data for 3-4 samples (as indicated in the description field).
Project description:Caligid copepods, also called sea lice, are common ectoparasites of wild and farmed marine fish. The salmon louse Lepeophtheirus salmonis (KrM-xyer, 1837) has emerged as a serious problem for salmon farming in the Northern hemisphere. The annual cost of sea lice to the global salmon mariculture industry has been estimated at M-^@300 million, of which the majority accounts for the cost of chemically treating the farmed salmon. The treatments available for salmonids with sea lice infestation have been limited with a large scale reliance on single products and the use of antiparasitics with similar modes of action, which when used over a long period of time can enhance the selection pressure for reduced sensitivity. Two L. salmonis laboratory strains, established from field isolates and differing in susceptibility to emamectin benzoate (EMB) were studied using a custom sea louse 15K oligonucleotide microarray and RT-qPCR. The aim of the present study was to identify differential expression of transcripts between these two strains to identify potential constitutive gene expression changes associated with reduced susceptibility to EMB. Adult male salmon lice were sampled without exposure to antiparasitic agents for the purpose of studying gene expression from unchallenged individuals. In this study changes in expression of Glutamate-gated Chloride channel (GluCl) subunits, considered the major target site for avermectin (AVM) drugs in invertebrates, was not observed, but expression changes were seen for alternative ligand-gated ion channel (LGIC) subunits that form an ion channels shown to interact with AVMs in vertebrates, but which is not traditionally considered to be a target site for AVMs in invertebrates. We hypothesise that these LGIC subunits represent additional EMB target sites in salmon lice, and that the down-regulation of these channel subunits in this EMB-resistant strain is related to the resistance phenotype.
Project description:This SuperSeries is composed of the following subset Series: GSE26981: Responses to ectoparasite salmon louse (Lepeophtheirus salmonis) in skin of Atlantic salmon GSE26984: Responses to ectoparasite salmon louse (Lepeophtheirus salmonis) in spleen of Atlantic salmon Refer to individual Series
Project description:Lepeophtheirus salmonis (sea lice) and bacterial co-infection threatens wild and farmed Atlantic salmon performance and welfare. The present microarray-based study examined the dorsal skin transcriptome response to formalin-killed Aeromonas salmonicida bacterin (ASAL) in pre-adult sea lice-infected and non-infected Atlantic salmon to fill the existing knowledge gap and aid in developing anti-co-infection strategies. To this aim, sea lice-infected and non-infected salmon were intraperitoneally injected with either phosphate-buffered saline (PBS) or ASAL (i.e., 4 injection/infection groups: PBS/no lice, PBS/lice, ASAL/no lice, and ASAL/lice). The analysis of the dorsal skin transcriptome data [Significance Analysis of Microarrays (5% FDR)] identified 345 up-regulated and 2,189 down-regulated DEPs in the comparison PBS/lice vs. PBS/no lice, and 82 up-regulated and 3 down-regulated DEPs in the comparison ASAL/lice vs. ASAL/no lice. The comparison ASAL/lice vs. PBS/lice identified 272 up-regulated and 11 down-regulated DEPs, whereas ASAL/no lice vs. PBS/no lice revealed 27 up-regulated DEPs. The skin transcriptome differences between the co-stimulated salmon (i.e., ASAL/lice) and PBS/no lice salmon accounted for 1,878 up-regulated and 3,120 down-regulated DEPs.
