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 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 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:Background: Salmonid species have followed markedly divergent evolutionary trajectories in their interactions with sea lice. While sea lice parasitism poses significant economic, environmental, and animal welfare challenges for Atlantic salmon (Salmo salar) aquaculture, coho salmon (Oncorhynchus kisutch) exhibit near-complete resistance to sea lice, achieved through a potent epithelial hyperplasia response leading to rapid louse detachment. The molecular mechanisms underlying these divergent responses to sea lice are unknown. Results: We characterised the cellular and molecular responses of Atlantic salmon and coho salmon to sea lice using single-nuclei RNA sequencing. Juvenile fish were exposed to copepodid sea lice (Lepeophtheirus salmonis), and lice-attached pelvic fin and skin samples were collected 12h, 24h, 36h, 48h, and 60h after exposure, along with control samples. Comparative analysis of control and treatment samples revealed an immune and wound-healing response that was common to both species, but attenuated in Atlantic salmon, potentially reflecting greater sea louse immunomodulation. Our results revealed unique but complementary roles of three layers of keratinocytes in the epithelial hyperplasia response leading to rapid sea lice rejection in coho salmon. Our results suggest that basal keratinocytes direct the expansion and mobility of intermediate and, especially, superficial keratinocytes, which eventually encapsulate the parasite. Conclusions: Our results highlight the key role of keratinocytes in coho salmon’s sea lice resistance, and the diverged biological response of the two salmonid host species when interacting with this parasite. This study has identified key pathways and candidate genes that could be manipulated using various biotechnological solutions to improve Atlantic salmon sea lice resistance.
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: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:Sea lice (e.g., Lepeophtheirus salmonis) are parasites causing costly disease outbreaks in salmon farming globally. Despite the currently available controlling practices, molecular insights into the parasite-induced host immune responses and host-pathogen interaction will provide the basis for improved and innovative treatment strategies. We investigated the early transcriptomic responses in the fins of Atlantic salmon parasitized with sea lice at the chalimus stage (8 days post-infection). Fin tissue collected from non-infected (PRE) control and at (ATT) and adjacent (ADJ) to chalimus-attachment sites from infected fish were used in profiling the global gene expression using a 44K microarray platform. Microarray analyses indicated that global transcriptomic changes resulted in 6,568 differentially expressed probes (DEPs, FDR < 5%) that include 1928 shared DEPs between ATT and ADJ compared to PRE. A direct comparison of ATT vs. ADJ revealed 90 DEPs, all of which were up-regulated in ATT.
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.
