Hepatic gene expression profiling reveals protective responses in Atlantic salmon vaccinated against furunculosis

<p>Abstract</p> <p>Background</p> <p>Furunculosis, a disease caused with gram negative bacteria <it>Aeromonas salmonicida </it>produces heavy losses in aquaculture. Vaccination against furunculosis reduces mortality of Atlantic salmon but fails to eradicate infection. Factors that determine high individual variation of vaccination efficiency remain unknown. We used gene expression analyses to search for the correlates of vaccine protection against furunculosis in Atlantic salmon.</p> <p>Results</p> <p>Naïve and vaccinated fish were challenged by co-habitance. Fish with symptoms of furunculosis at the onset of mass mortality (LR - low resistance) and survivors (HR - high resistance) were sampled. Hepatic gene expression was analyzed with microarray (SFA2.0 - immunochip) and real-time qPCR. Comparison of LR and HR indicated changes associated with the protection and results obtained with naïve fish were used to find and filter the vaccine-independent responses. Genes involved in recruitment and migration of immune cells changed expression in both directions with greater magnitude in LR. Induction of the regulators of immune responses was either equal (NFkB) or greater (Jun) in LR. Expression levels of proteasome components and extracellular proteases were higher in LR while protease inhibitors were up-regulated in HR. Differences in chaperones and protein adaptors, scavengers of reactive oxygen species and genes for proteins of iron metabolism suggested cellular and oxidative stress in LR. Reduced levels of free iron and heme can be predicted in LR by gene expression profiles with no protection against pathogen. The level of complement regulation was greater in HR, which showed up-regulation of the components of membrane attack complex and the complement proteins that protect the host against the auto-immune damages. HR fish was also characterized with up-regulation of genes for proteins involved in the protection of extracellular matrix, lipid metabolism and clearance of endogenous and exogenous toxic compounds. A number of genes with marked expression difference between HR and LR can be considered as positive and negative correlates of vaccine protection against furunculosis.</p> <p>Conclusion</p> <p>Efficiency of vaccination against furunculosis depends largely on the ability of host to neutralize the negative impacts of immune responses combined with efficient clearance and prevention of tissue damages.</p

På rett vei? Om statlig virkemiddelbruk på det kommunale på rus-og psykiatrifeltet

Forholdet mellom stat og kommune kan beskues ut fra mange ståsted. Vårt ståsted har vært kommunens, med fokus på tjenestetilbud på rus- og psykiatrifeltet. Siden 1990-tallet har staten gjennom lovgivning og annen virkemiddelbruk pålagt kommunene et stadig større ansvar for iverksettelse av nasjonal politikk på helse og omsorgsfeltet. Rus- og psykiatrifeltet er imidlertid et tjenesteområde som fort kan forsvinne i skyggen av større og mer «tyngende» kommunale helse- og omsorgsoppgaver. Rus- og psykiatrifeltet er et felt som kanskje heller ikke vekker det store engasjementet blant storparten av innbyggerne i kommunen. Vår intensjon med denne masteravhandlingen er å sette fokus på et lite og sårbart, men særdeles viktig kommunalt ansvarsområde. Rus- og psykiatrifeltet er et politikkområde som periodevis har fått stor oppmerksomhet fra sentrale myndigheter. Gjennom en nasjonal opptrappingsplan for psykiatrifeltet med øremerkede tilskudd i perioden 1999-2008, bygde de fleste kommuner ut tjenestetilbud i tråd med intensjonene. Psykiatriplanen ble så etterfulgt av en opptrappingsplan for rusfeltet i perioden 2008-2012. Gjennom økte rammetilskudd og tilskuddsordninger ønsket en fra nasjonalt hold å opprettholde og sikre en videre kommunal satsing på rus- og psykiatrifeltet. I 2012 ble tilskuddsordningene lagt i det ordinære rammetilskuddet til kommunene, men i 2013 gjeninnførte Regjeringen ordningen med tilskuddsordninger. En rekke evalueringer har imidlertid vist at det kommunale rus- og psykiatrifeltet ikke har fått nevneverdige økte ressurser siden 2008. Dette til tross for at behovene for tjenester har vært, og fortsatt er, økende. En ny opptrappingsplan er nå gjort gjeldende for perioden 2016-2020. Gjennom økte rammer og bruk av tilskuddsordninger vil staten stimulere og påvirke kommunene til videre innsats på rus- og psykiatrifeltet, ikke minst i forhold til samhandling med andre kommunale instanser og med spesialisthelsetjenesten. Dette danner bakgrunnsteppet for tema i vår masteravhandling. Ut fra en kvalitativ tilnærming har vi gjennomført en komparativ case-studie i to kommuner. Gjennom dokumentstudier og intervjuer med ulike aktørerer, har vi sett på hvordan statlige finansieringsordninger påvirker det kommunale handlingsrommet på rus- og psykiatrifeltet. Vi har også undersøkt i hvilken grad annen statlig virkemiddelbruk, som lovgivning, rådgivning/veiledning og bruk av tilsyn og kontroll er egnede virkemidler for å iverksette politikken, og vil således forsøke å besvare spørsmålet om hvilken virkemiddelbruk som er best egnet for å sikre at ønsket nasjonal politikk på rus- og psykiatrifeltet blir implementert på kommunalt nivå. Studien vår tar hensyn til faktorer som brukertilfredshet/brukerorientering, kvalitative tjenestetilbud, effektivitet og kommunalt selvstyre. Vi finner at aktører både på politisk, administrativt og tjenesteutøvende nivå, støtter opp om de nasjonale målsetningene for rus- og psykiatrifeltet. Funnene våre viser imidlertid at det er ulike meninger blant aktørene om hvilken statlig virkemiddelbruk, og hvilke finansieringsordninger som gir optimal tjenestelevering og størst kommunalt handlingsrom på rus- og psykiatrifeltet. Våre funn tyder også på at statlige finansieringsordninger har liten betydning for hvordan tjenestetilbudene er organisert, men derimot har organiseringen stor betydning for å nå nasjonale mål om helhetlige og samordnede tjenestetilbud på rus- og psykiatrifeltet

Effects of chilled storage and cryopreservation of sperm, and sperm to egg ratio on fertilization success in lumpfish (Cyclopterus lumpus)

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Welfare and performance of ballan wrasse (Labrus bergylta) reared at two different temperatures after a preparatory feeding trial with enhanced dietary eicosapentaenoic acid

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Genetic (co)variance of rainbow trout (Oncorhynchus mykiss) body weight and its uniformity across production environments

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Quantitative genetics of taura syndrome resistance in pacific white shrimp (penaeus vannamei): a cure model approach

<p>Abstract</p> <p>Background</p> <p>In aquaculture breeding, resistance against infectious diseases is commonly assessed as time until death under exposure to a pathogen. For some diseases, a fraction of the individuals may appear as "cured" (non-susceptible), and the resulting survival time may thus be a result of two confounded underlying traits, i.e., endurance (individual hazard) and susceptibility (whether at risk or not), which may be accounted for by fitting a cure survival model. We applied a cure model to survival data of Pacific white shrimp (<it>Penaeus vannamei</it>) challenged with the Taura syndrome virus, which is one of the major pathogens of Panaeid shrimp species.</p> <p>Methods</p> <p>In total, 15,261 individuals of 513 full-sib families from three generations were challenge-tested in 21 separate tests (tanks). All challenge-tests were run until mortality naturally ceased. Time-until-event data were analyzed with a mixed cure survival model using Gibbs sampling, treating susceptibility and endurance as separate genetic traits.</p> <p>Results</p> <p>Overall mortality at the end of test was 28%, while 38% of the population was considered susceptible to the disease. The estimated underlying heritability was high for susceptibility (0.41 ± 0.07), but low for endurance (0.07 ± 0.03). Furthermore, endurance and susceptibility were distinct genetic traits (r_g= 0.22 ± 0.25). Estimated breeding values for endurance and susceptibility were only moderately correlated (0.50), while estimated breeding values from classical models for analysis of challenge-test survival (ignoring the cured fraction) were closely correlated with estimated breeding values for susceptibility, but less correlated with estimated breeding values for endurance.</p> <p>Conclusions</p> <p>For Taura syndrome resistance, endurance and susceptibility are apparently distinct genetic traits. However, genetic evaluation of susceptibility based on the cure model showed clear associations with standard genetic evaluations that ignore the cure fraction for these data. Using the current testing design, genetic variation in observed survival time and absolute survival at the end of test were most likely dominated by genetic variation in susceptibility. If the aim is to reduce susceptibility, earlier termination of the challenge-test or back-truncation of the follow-up period should be avoided, as this may shift focus of selection towards endurance rather than susceptibility.</p

Digital phenotyping of individual feed intake in Atlantic salmon (Salmo salar) with the X-ray method and image analysis

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Genomic and Transcriptomic Analysis of Amoebic Gill Disease Resistance in Atlantic Salmon (Salmo salar L.)

Amoebic gill disease (AGD) is one of the most important parasitic diseases of farmed Atlantic salmon. It is a source of major economic loss to the industry and poses significant threats to animal welfare. Previous studies have shown that resistance against this disease has a moderate, heritable genetic component, although the genes and the genetic pathways that contribute to this process have yet to be elucidated. In this study, to identify the genetic mechanisms of AGD resistance, we first investigated the molecular signatures of AGD infection in Atlantic salmon through a challenge model, where we compared the transcriptome profiles of the naïve and infected animals. We then conducted a genome-wide association analysis with 1,333 challenged tested fish to map the AGD resistance genomic regions, supported by the results from the transcriptomic data. Further, we investigated the potential of incorporating gene expression analysis results in genomic prediction to improve prediction accuracy. Our data suggest thousands of genes have modified their expression following infection, with a significant increase in the transcription of genes with functional properties in cell adhesion and a sharp decline in the abundance of various components of the immune system genes. From the genome-wide association analysis, QTL regions on chromosomes ssa04, ssa09, and ssa13 were detected to be linked with AGD resistance. In particular, we found that QTL region on ssa04 harbors members of the cadherin gene family. These genes play a critical role in target recognition and cell adhesion. The QTL region on ssa09 also is associated with another member of the cadherin gene family, protocadherin Fat 4. The associated genetic markers on ssa13 span a large genomic region that includes interleukin-18-binding protein, a gene with function essential in inhibiting the proinflammatory effect of cytokine IL18. Incorporating gene expression information through a weighted genomic relationship matrix approach decreased genomic prediction accuracy and increased bias of prediction. Together, these findings help to improve our breeding programs and animal welfare against AGD and advance our knowledge of the genetic basis of host-pathogen interactions

Applying genetic technologies to combat infectious diseases in aquaculture

Disease and parasitism cause major welfare, environmental and economic concerns for global aquaculture. In this review, we examine the status and potential of technologies that exploit genetic variation in host resistance to tackle this problem. We argue that there is an urgent need to improve understanding of the genetic mechanisms involved, leading to the development of tools that can be applied to boost host resistance and reduce the disease burden. We draw on two pressing global disease problems as case studies—sea lice infestations in salmonids and white spot syndrome in shrimp. We review how the latest genetic technologies can be capitalised upon to determine the mechanisms underlying inter- and intra-species variation in pathogen/ parasite resistance, and how the derived knowledge could be applied to boost disease resistance using selective breeding, gene editing and/or with targeted feed treatments and vaccines. Gene editing brings novel opportunities, but also implementation and dissemination challenges, and necessitates new protocols to integrate the technology into aquaculture breeding programmes. There is also an ongoing need to minimise risks of disease agents evolving to overcome genetic improvements to host resistance, and insights from epidemiological and evolutionary models of pathogen infestation in wild and cultured host populations are explored. Ethical issues around the different approaches for achieving genetic resistance are discussed. Application of genetic technologies and approaches has potential to improve fundamental knowledge of mechanisms affecting genetic resistance and provide effective pathways for implementation that could lead to more resistant aquaculture stocks, transforming global aquaculture.publishedVersio