Transcriptomics of coping strategies in free-swimming Lepeophtheirus salmonis (Copepoda)
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ABSTRACT: To understand the sensitivity of larval lice to changing environmental parameters we applied a 38K oligo microarray and characterized transcriptome responses after 24 hour exposures to reduced salinity (30-10 parts per thousand (ppt)) or varied temperature (16-4M-BM-:C). To further characterize the effects of salinity, we profiled expression changes over a range of seawater with single increment differences (30-25 ppt). Three separate projects. Low resolution salinity (aka wide range or LR_SAL) contains 2 duplicate experiments, each with pools of lice (~500 copepodid lice per beaker; n=3 beakers per condition), incubated for 24 hr at 10M-BM-:C diluted to 30, 25, 20, or 10 parts per thousand (ppt). Temperature study conducted as above, but with a constant salinity of 30 ppt and changed temperature of 4, 10, or 16M-BM-:C. High resolution salinity conducted as above, but with no experiment replication, but with biological repication of n=6 beakers per condition, and with a range of 25, 26, 27, 28, 29, 30 ppt salinity. Please note that each experiment was normalized separately.
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. Two separate experiments were conducted, one for Atlantic and one for Pacific salmon lice (to be analyzed separately). Atlantic pre-adult salmon lice, separated into male and female, and sensitive or resistant to EMB populations, and exposed to a dilution series: 0 (control), 0.1, 25, 300, and 1000 parts per billion EMB. For each combination four biological replicates were included, except male resistant 25 (n = 3) and female resistant 300 (n = 2). Pacific pre-adult lice of both sexes were exposed to a dilution series: 0 (control), 25, 50 parts per billion EMB.
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: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:To understand the sensitivity of larval lice to changing environmental parameters we applied a 38K oligo microarray and characterized transcriptome responses after 24 hour exposures to reduced salinity (30-10 parts per thousand (ppt)) or varied temperature (16-4ºC). To further characterize the effects of salinity, we profiled expression changes over a range of seawater with single increment differences (30-25 ppt).
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: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. The aim of the present study was to identify transcripts whose expression correlated to emamectin benzoate (EMB) susceptibility, or those genes regulated in response to EMB exposure. Two L. salmonis laboratory strains, established from field isolates and differing in susceptibility to EMB were studied using a custom sea louse 15K oligonucleotide microarray and RT-qPCR. Adult male sea lice were sampled from both strains after 1 and 3 hours of aqueous exposure to 0.2 M-5g mL-1 emamectin benzoate, 0.01% PEG300 or sea water. Bioinformatic analysis identified that in the absence of drug treatment, a large number of genes were significantly down regulated in the louse strain hyposensitive to EMB. EMB exposure had marked effects on gene expression in the EMB susceptible strain, but caused little changes in EMB hyposensitive lice. We therefore suggest that transcriptional responses induced by EMB exposure may not be responsible for reduced susceptibility to this antiparasitic compound, but may involve genes that are constitutively expressed in EMB tolerant salmon louse strains.
Project description:This project is aiming to examine the molecular response of the blue mussel (Mytilus edulis) to increased air temperatures and reduced salinity under laboratory conditions. There are 5 treatment groups (n=5), with group A representing the control (salinity 23percent salinity and temperature 5 degree celsius), group B ( 23percent salinity 30 degree celsius), group C (23percent salinity 33 degree celsius), group D (15percent salinity 5 degree celsius), group E (15percent salinity 30 degree celsius), group F (15percent salinity33 degree celsius), group G (5percent salinity 5 degree celsius).
Project description:We applied tandem mass tag (TMT)-based quantitative proteomic analysis to investigate the basal protein differences among worms growing under different salinity environments.
Project description:Low salinity is one of the main factors limiting the distribution and survival of marine species. As estuarine species, Crassostrea hongkongensis can live in relative low salinity. Through Illumina sequencing, we generated two transcriptomes with samples taken from gills of oysters exposed to the low salinity seawater versus the optimal seawater. By RNAseq technology, we found 13550 up-regulation genes and 9914 down-regulation genes that may regulate osmotic stress in C. hongkongensis. As blasted by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes regulated significantly were dominated in structural molecule activity, intracellular,cytoplasm protein metabolism, biosynthesis,cell and transcription regulator activity according to GO annotation. The study aimed to compare the expression data of the two transcriptomes to provide some useful insights into signal transduction pathways in oysters and offer a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. hongkongensis transcriptome will facilitate research into biological processes underlying physiological adaptations to hypoosmotic shock for marine invertebrates. Twelve oysters were exposed in low salinity (8‰) seawater and in optimal salinity (25‰) seawater,respectively. Gills from six oysters in each condition were balanced mixed respectively. The transcriptomes of two samples were generated by deep sequencing, using Illumina HiSeq2000
Project description:Comparison of freshwater tolerant (accession CCAP 1310/196, origin Hopkins River Falls, Victoria, Australia) and strictly marine strain (accession CCAP 1310/4, origin San Juan de Marcona, Peru) of E. siliculosus under different salinites