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:The influence of GH transgenesis on liver gene expression in coho salmon was examined. Gene expression in livers of transgenic salmon on a restricted ration (R) was compared to that in livers of nontransgenic control salmon (C). Keywords: Transcript profile
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:We investigated whether exposure to a captive environment during maturation influenced gamete DNA methylation for wild Atlantic Salmon individuals. We then investigated whether these parental effects were detectable in an F1 generation reared in a common environment. We associated DNA methylation with growth and fitness-related phenotypes and demonstrated that intergenerational effects of hatchery exposure during maturation of the parental generation influence fitness-related methylation patterns in the F1 generation.
Project description:The study was designed to investigate the impacts of hatchery spawning and rearing on steelhead trout (Oncorhynchus mykiss) versus the wild fish on a molecular level. Additionally, epigenetic differences between feeding practices that allow slow growth and fast growth hatchery trout were investigated. The sperm and RBC DNA both had a large number of DMRs when comparing the hatchery versus wild steelhead trout populations. Interestingly, the DMRs were cell type specific with negligible overlap. Slow growth compared to fast growth steelhead also had a larger number of DMRs in the RBC samples. Observations demonstrate a major epigenetic programming difference between the hatchery and wild fish populations, but negligible genetic differences. Therefore, hatchery conditions and growth rate can alter the epigenetic developmental programming of the steelhead trout, which may correlate to the phenotypic variations observed.
