Gene expression analyses in Atlantic salmon challenged with infectious salmon anemia virus reveal differences between individuals with early, intermediate and late mortality

<p>Abstract</p> <p>Background</p> <p>Infectious salmon anemia virus (ISAV) causes a multisystemic disease responsible for severe losses in salmon aquaculture. Better understanding of factors that explain variations in resistance between individuals and families is essential for development of strategies for disease control. To approach this, we compared global gene expression using microarrays in fish dying early and late in the time course following infection from a highly pathogenic ISAV.</p> <p>Results</p> <p>Tissues (gill, heart, liver and spleen) from infected Atlantic salmon (cohabitation, ISAV Glesvaer 2/90 isolate) were collected from three stages over the time course of the experiment; early (EM, 0–10% cumulative mortality (CM), 21–25 days post-infection (DPI)), intermediate (IM, 35–55% CM, 28–31 DPI) and late (LM, 75–85% CM, 37–48 DPI) mortality. Viral loads were equal in EM and IM but dropped markedly in LM fish. Gene expression analyses using a 1.8 K salmonid fish cDNA microarray (SFA2.0) and real-time qPCR revealed a large group of genes highly up-regulated across tissues in EM, which were mainly implicated in innate antiviral responses and cellular stress. Despite equal levels of MHC class I in EM and LM, increase of splenic and cardiac expression of immunoglobulin-like genes was found only in LM while a suite of adaptive immunity markers were activated already in IM. The hepatic responses to ISAV were characterized by difference between EM and LM in expression of chaperones and genes involved in eicosanoid metabolism. To develop classification of high and low resistance phenotypes based on a small number of genes, we processed results from qPCR analyses of liver using a linear discriminant analysis. Four genes (5-lipoxygenase activating protein, cytochrome P450 2K4-1, galectin-9 and annexin A1) were sufficient for correct assignment of individuals to EM, LM and uninfected groups, while IM was inseparable from EM. Three of four prognostic markers are involved in metabolism of inflammatory regulators.</p> <p>Conclusion</p> <p>This study adds to the understanding of molecular determinants for resistance to acute ISAV infection. The most susceptible individuals were characterized by high viral replication and dramatic activation of innate immune responses, which did not provide protection. The ability to endure high levels of infection for sustained periods could be associated with lower inflammatory responses while subsequent protection and viral clearance was most likely conferred by activation of adaptive immunity.</p

Transcribed Tc1-like transposons in salmonid fish

BACKGROUND: Mobile genetic elements comprise a substantial fraction of vertebrate genomes. These genes are considered to be deleterious, and in vertebrates they are usually inactive. High throughput sequencing of salmonid fish cDNA libraries has revealed a large number of transposons, which remain transcribed despite inactivation of translation. This article reports on the structure and potential role of these genes. RESULTS: A search of EST showed the ratio of transcribed transposons in salmonid fish (i.e., 0.5% of all unique cDNA sequences) to be 2.4–32 times greater than in other vertebrate species, and 68% of these genes belonged to the Tc1-family of DNA transposons. A phylogenetic analysis of reading frames indicate repeated transposition of distantly related genes into the fish genome over protracted intervals of evolutionary time. Several copies of two new DNA transposons were cloned. These copies showed relatively little divergence (11.4% and 1.9%). The latter gene was transcribed at a high level in rainbow trout tissues, and was present in genomes of many phylogenetically remote fish species. A comparison of synonymous and non-synonymous divergence revealed remnants of divergent evolution in the younger gene, while the older gene evolved in a neutral mode. From a 1.2 MB fragment of genomic DNA, the salmonid genome contains approximately 10(5 )Tc1-like sequences, the major fraction of which is not transcribed. Our microarray studies showed that transcription of rainbow trout transposons is activated by external stimuli, such as toxicity, stress and bacterial antigens. The expression profiles of Tc1-like transposons gave a strong correlation (r(2 )= 0.63–0.88) with a group of genes implicated in defense response, signal transduction and regulation of transcription. CONCLUSION: Salmonid genomes contain a large quantity of transcribed mobile genetic elements. Divergent or neutral evolution within genomes and lateral transmission can account for the diversity and sustained persistence of Tc1-like transposons in lower vertebrates. A small part of transposons remain transcribed and their transcription is enhanced by responses to acute conditions

A sensorless initial rotor position's estimation for permanent magnet synchronous machines

Permanent magnet synchronous motors for the effective start require information about the initial position of a rotor. In this regard, most systems use position sensors, which substantially increase entirely a cost of an electrical drive [1-3]. The aim of this article is to develop a new method, allowing determining the absolute angular position of the permanent magnet synchronous motors' rotor [4,5]. With a certain voltage pulses applied to the motor, its stator is magnetized by currents leakage in the windings. This allows using a special algorithm to calculate the absolute position of the rotor without using any motor parameters [6]. Simulation results prove the simplicity and efficiency of this method for determining an initial position of the permanent magnet synchronous motors' rotor. Thus, this method can be widely used in the electrical industry

Estrogen Modulates Hepatic Gene Expression and Survival of Rainbow Trout Infected with Pathogenic Bacteria Yersinia ruckeri

In the aquatic environment, fish are exposed to various stimuli at once and have developed different response mechanisms to deal with these multiple stimuli. The current study assessed the combined impacts of estrogens and bacterial infection on the physiological status of fish. Juvenile rainbow trout were exposed to two different concentrations of 17β-estradiol (E2) (2 or 20mg/kg feed) and then infected with three concentrations of Yersinia ruckeri, a bacterial pathogen causing massive losses in wild and farmed salmonid populations. Organism-level endpoints to assess the impact of the single and combined treatments included hepatic vitellogenin transcript expression to evaluate the E2 exposure efficiency and survival rate of pathogen-challenged fish. The two E2 doses increased vitellogenin levels within the physiological range. Infection with Y. ruckeri caused mortality of trout, and this effect was significantly enhanced by a simultaneous exposure to high E2 dose. The hormone reduced survival at intermediate and high (104 and 106 colony forming units, cfu) bacterial concentrations, but not for a low one (102cfu). Analysis of hepatic gene expression profiles by a salmonid 2k cDNA microarray chip revealed complex regulations of pathways involved in immune responses, stress responses, and detoxicification pathways. E2 markedly reduced the expression of several genes implicated in xenobiotic metabolism. The results suggest that the interaction between pathogen and E2 interfered with the fish's capability of clearing toxic compounds. The findings of the current study add to our understanding of multiple exposure responses in fis

Geosituational modelling of coastal marine systems

The article summarizes years of experience of geosituational modelling of coastal marine systems in the Baltic Sea region and adjacent territories. Kaliningrad universities and academic institutions have done extensive research on the diversity of approaches and models of the regional geosituations as well as on identifying the most promising coastal marine areas. Some of the models presented in the present paper are qualitative, while others are empirical and statistical ones. However, the majority of the models can be referred to as forms of graphic and image mapping. The significance of the regional models lies in their specificity, a more detailed character (compared to the generalist ones) and the possibility of using them to back up managerial decisions in critical and emergency situations in order to minimize the negative effects of natural (storms, floods, earthquakes, etc.) and anthropogenic emergency situations. The authors developed a matrix classification attributable to a particular class of models for the situations leading to uncertain outcomes. The authors suggest using numerical methods combined with the empirical and statistical models for the assessment of the impact of industrial fishing on marine environment, minimizing the consequences of storms, floods and others factors. Special attention is paid to the modelling of climate change and geo-ecological consequences, as well as to atlas mapping and landscape planning. As a result of the geosituational analysis the authors got new insights into the solar-terrestrial links, marine-terrestrial ecosystems, global and regional processes related to climate change, oceanization, the vulnerability of natural systems under the increasing pressure of anthropogenic activities, and continuously increasing risks presented by industrial agriculture and other types of land use

Developmental disturbances in early life stage mortality (M74) of Baltic salmon fry as studied by changes in gene expression

BACKGROUND: We have studied alterations of gene expression associated with naturally-occurring early life stage mortality (M74) in Baltic salmon using a cDNA microarray and real time PCR. M74-affected fry have several typical neurological, cardiovascular and pathological symptoms. They are also characterized by low thiamine content and show signs of oxidative stress. RESULTS: Affected fry can be divided into three major groups with early, intermediate or late onset of mortality. If mortality starts during the first third of the yolk-sac stage, virtually all the responses are compatible with stress, which rapidly leads to the common terminal responses. If death occurs during the second third of the yolk sac stage, the terminal stage is preceded by a decrease in globin gene expression, which leads to internal hypoxia when the animals grow and shift from skin- to gill-breathing. Fry will eventually proceed to the terminal responses. The group developing M74 most slowly appears to compensate for reduced oxygen delivery by downregulation of metabolism, and hence some fry can escape death. CONCLUSION: Our study is the first demonstration of diverse transcriptional responses to a naturally-occurring developmental disturbance. Since many of the genes differentially expressed in M74-fry are evolutionarily conserved, the M74 of Baltic salmon can serve as a model for developmental disturbances and environmental stress responses in vertebrates in general

Evaluation of Immune Status in Two Cohorts of Atlantic Salmon Raised in Different Aquaculture Systems (Case Study)

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Barn och unga med neuropsykiatriska funktionsnedsättningar. I ett glapp mellan LVU och LPT?

Gränsdragningen mellan lag (1990:52) med särskilda bestämmelser om vård av unga (LVU) och lag (1991:1128) om psykiatrisk tvångsvård (LPT) har länge varit föremål för diskussion. Det finns idag barn och unga med beteendeproblematik som varken uppfyller kriterierna för tvångsvård enligt LVU eller LPT. Det är dessa barn, mer specifikt barn och unga med neuropsykiatriska funktionsnedsättningar och beteendeproblematik, som är i fokus i denna uppsats. Högsta förvaltningsdomstolen har genom två avgöranden från 2010 skapat en praxis som innebär en mer restriktiv tolkning av rekvisitet något annat socialt nedbrytande beteende i 3§ LVU. Dessa avgöranden, RÅ 2010 ref. 24 samt mål nr. 8480-08, innebär att ett beteende som närmast, eller i huvudsak, kan betraktas som ett symptom på ett psykiskt funktionshinder inte kan utgöra ett sådant socialt nedbrytande beteende som avses i 3§ LVU. Därmed utesluts ett beslut om tvångsvård enligt nämnda bestämmelse många gånger för barn och unga med psykisk problematik. Denna uppsats behandlar frågan om hur, och i vilken utsträckning, de ovan nämnda avgörandena har påverkat och påverkar möjligheten till tvångsvård för barn och unga med neuropsykiatriska funktionsnedsättningar. Med syfte att undersöka effekterna av den tillämpning av Högsta förvaltningsdomstolens avgöranden som sker i förvaltning- och kammarrätterna genomförs en empirisk undersökning där jag framförallt har studerat och analyserat avgöranden från första instans. I studien undersöks om denna tillämpning står i överensstämmelse med lagstiftningen och HFD:s avgöranden. Syftet är att undersöka rätten i faktisk mening, det vill säga hur den i realiteten tillämpas eftersom att det är rättstillämpningen i första instans som är avgörande för medborgarnas reella rättigheter och skyldigheter. I uppsatsen utvärderas även den i SOU 2015:71 föreslagna ändringen av rekvisitet något annat socialt nedbrytande beteende i 3§ LVU. Ändringen innebär att det nuvarande rekvisitet ersätts med rekvisitet något annat i sig självt socialt nedbrytande beteende. Förslaget har fått kritik från många aktörer och det uttrycks i ett flertal remissvar oro för att barn med neuropsykiatriska funktionsnedsättningar kommer att påverkas negativt av denna förändring. I uppsatsen undersöks om tillägget ”i sig självt” kan möjliggöra att samhället i större utsträckning än idag kommer kunna tillgodose de berörda barnen och ungas vårdbehov. Uppsatsen är skriven ur ett barnrättsperspektiv med särskilt fokus mot rättssäkerhet. Med utgångspunkt i detta perspektiv analyseras i vilken utsträckning behoven hos barn och unga med neuropsykiatriska funktionsnedsättningar tillgodoses genom det skydd och den vård som samhället åtagit sig att ansvara för. Vidare analyseras om den föreslagna ändringen kan leda till att den problematik som har uppkommit efter HFD:s praxis kan lösas på ett etiskt godtagbart sätt. En slutsats i uppsatsen är att det, för att förändringen ska vara etiskt godtagbar, krävs en utveckling av kvaliteten i de vårdinsatser som följer av beslut enligt 3§ LVU och att kvaliteten i underlaget för LVU-besluten i kammar- och förvaltningsrätterna förbättras