Evolution and differential expression of a vertebrate vitellogenin gene cluster

<p>Abstract</p> <p>Background</p> <p>The multiplicity or loss of the vitellogenin (<it>vtg</it>) gene family in vertebrates has been argued to have broad implications for the mode of reproduction (placental or non-placental), cleavage pattern (meroblastic or holoblastic) and character of the egg (pelagic or benthic). Earlier proposals for the existence of three forms of vertebrate <it>vtgs </it>present conflicting models for their origin and subsequent duplication.</p> <p>Results</p> <p>By integrating phylogenetics of novel <it>vtg </it>transcripts from old and modern teleosts with syntenic analyses of all available genomic variants of non-metatherian vertebrates we identify the gene orthologies between the Sarcopterygii (tetrapod branch) and Actinopterygii (fish branch). We argue that the vertebrate <it>vtg </it>gene cluster originated in proto-chromosome m, but that <it>vtg </it>genes have subsequently duplicated and rearranged following whole genome duplications. Sequencing of a novel fourth <it>vtg </it>transcript in labrid species, and the presence of duplicated paralogs in certain model organisms supports the notion that lineage-specific gene duplications frequently occur in teleosts. The data show that the <it>vtg </it>gene cluster is more conserved between acanthomorph teleosts and tetrapods, than in ostariophysan teleosts such as the zebrafish. The differential expression of the labrid <it>vtg </it>genes are further consistent with the notion that neofunctionalized Aa-type <it>vtgs </it>are important determinants of the pelagic or benthic character of the eggs in acanthomorph teleosts.</p> <p>Conclusion</p> <p>The vertebrate <it>vtg </it>gene cluster existed prior to the separation of Sarcopterygii from Actinopterygii >450 million years ago, a period associated with the second round of whole genome duplication. The presence of higher copy numbers in a more highly expressed subcluster is particularly prevalent in teleosts. The differential expression and latent neofunctionalization of <it>vtg </it>genes in acanthomorph teleosts is an adaptive feature associated with oocyte hydration and spawning in the marine environment.</p

Kako poplave modifikuju genotoksični odgovor slatkovodnih riba?

U ovom radu ispitivan je potencijal dve vrste roda Abramis (Abramis bjoerkna i Abramis sapa) kao bioindikatora genotoksičnog potencijala vode reke Save primenom komet testa. Izabrani lokalitet pripada oblasti intezivne poljoprivredne aktivnosti, izložen je otpadnim vodama grada Obrenovca i nalazi se u blizini najveće termoelektrane u Srbiji, “Nikola Tesla”. Uzorkovanje je vršeno od januara do avgusta 2014. godine, obuhvatajući mesec maj kada je došlo do intezivnih poplava u slivu reke Save. Dobijeni rezultati ukazuju da se ispitivane vrste mogu koristiti za procenu genotoksičnog potencijala

A novel miniaturized biosensor for monitoring atlantic salmon swimming activity and respiratory frequency

Good fish welfare is one of the prerequisites for sustainable aquaculture. Knowing how fish respond to the production conditions would allow us to better understand their biology and to further optimize production. The new miniaturized biosensor AEFishBIT was successfully used to monitor individual physical activity and respiratory frequency of two Mediterranean farmed fish species (gilthead sea bream and European sea bass). In this study, we aimed to test the use of AEFishBIT to monitor the performance of Atlantic salmon under experimental conditions. An adapted tagging procedure for salmon was developed and used to record salmon responses to handling and changing light conditions. AEFishBIT data showed a stabilization of swimming activity 8 h after handling and tagging with changes in activity or activity and respiratory quotient after changes in light intensity regimes. The results of this study supported the use of AEFishBIT to generate new behavior insights in Atlantic salmon culture.publishedVersio

Consequences of continuous ozonation on the health and welfare of Atlantic salmon post-smolts in a brackish water recirculating aquaculture system

Research Areas: Marine & Freshwater Biology ; ToxicologyThis study investigated the biological consequences of 45-day continuous ozonation on Atlantic salmon (Salmo salar) post-smolts in a brackish water recirculating aquaculture system (RAS). There was no significant difference in survival, operational welfare indicators, and average weight at termination between the ozone-treated and control groups. Plasma biochemical analyses revealed that the creatinine level was significantly higher in the ozone-treated group than in the control at termination. Histological evaluation of skin health showed no significant difference between the two groups. On the other hand, quantitative histopathology disclosed that the ozone group exhibited a better gill health status than did the control group, particularly at the end of the trial. Mucosal transcriptomics revealed a distinct response profile between the gills and skin. At day 45, there were no differentially expressed genes (DEG) identified in the skin, in contrast to 242 ozone-induced DEGs in the gills. Assessment of the transcriptomic profiles over time revealed that temporal effects were of greater impact in skin compared to gills, regardless of the treatment. The treatment did not result in metabolomic dysregulation and the overall profile lent support to the transcriptomics data that temporal effects had a greater influence on the changes observed. Exposure to handling-confinement stress revealed that ozone treatment did not alter the ability of post-smolts to respond to a secondary stressor. In summary, the suite of health and welfare indicators collectively indicated that continuous ozonation resulted in minimal physiological perturbations in salmon postsmolts. The results are expected to contribute to optimising the rearing conditions for post-smolts in RAS.info:eu-repo/semantics/publishedVersio

Photoperiod in recirculation aquaculture systems and timing of seawater transfer affect seawater growth performance of Atlantic salmon (Salmo salar)

Production of Atlantic salmon smolts in recirculation aquaculture systems (RAS) is growing, and novel production protocols using continuous light in RAS are being implemented in the industry. In the present study, Atlantic Salmon parr were exposed to either a traditional protocol (short-day winter signal [12:12 L:D] for 6 weeks) or to continuous light. Both photoperiods were applied in freshwater (FW) and brackish water RAS. Salmon from all treatments were transferred to seawater pens at 200 and 600 g and grown until slaughter size. A control group was smoltified with a 6-week short-day winter signal and kept in FW until sea transfer at 100 g. Continuous light gave a higher growth rate in RAS but reduced feed intake and growth and increased feed conversion ratio during the first 8 weeks in seawater. However, at slaughter, fish exposed to continuous light was bigger than fish given a winter signal because of the higher growth rate in RAS. Slaughter weight was lowest in fish transferred to sea at 600 g, despite having the highest day-degree sum during their life span. The best performing group was the control group transferred at 100 g. All treatments handled transfer to seawater and survival and maturation were not affected by the treatments in RAS. The immune status was examined with a multigene expression assay on BioMark HD platform from parr stage to 5–7 months after seawater transfer. Overall, there was no significant effect of photoperiod or salinity on the expression of the selected immune genes. In sum, the results from this study indicate that using continuous light in RAS may have negative effects on performance shortly after transfer in fish transferred to sea at 200 g, whereas at 600 g, all treatments had reduced growth after transfer irrespective of treatment in RAS.publishedVersio

Impact of ozone treatment on dissolved organic matter in land-based recirculating aquaculture systems studied by Fourier transform ion cyclotron resonance mass spectrometry

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Stress Impairs Skin Barrier Function and Induces α2-3 Linked N-Acetylneuraminic Acid and Core 1 O-Glycans on Skin Mucins in Atlantic Salmon, Salmo salar

The skin barrier consists of mucus, primarily comprising highly glycosylated mucins, and the epithelium. Host mucin glycosylation governs interactions with pathogens and stress is associated with impaired epithelial barrier function. We characterized Atlantic salmon skin barrier function during chronic stress (high density) and mucin O-glycosylation changes in response to acute and chronic stress. Fish held at low (LD: 14–30 kg/m3) and high densities (HD: 50-80 kg/m3) were subjected to acute stress 24 h before sampling at 17 and 21 weeks after start of the experiment. Blood parameters indicated primary and secondary stress responses at both sampling points. At the second sampling, skin barrier function towards molecules was reduced in the HD compared to the LD group (Papp mannitol; p < 0.01). Liquid chromatography–mass spectrometry revealed 81 O-glycan structures from the skin. Fish subjected to both chronic and acute stress had an increased proportion of large O-glycan structures. Overall, four of the O-glycan changes have potential as indicators of stress, especially for the combined chronic and acute stress. Stress thus impairs skin barrier function and induces glycosylation changes, which have potential to both affect interactions with pathogens and serve as stress indicators. View Full-TextpublishedVersio

Primena IBR metode (Integrated Biomarker Response) u mikrobiološkoj analizi vodenih ekosistema

UVOD: Mikrobiološki indikatori sanitarnog i organskog zagađenja čine neophodan segment svake procene kvaliteta vode. Međutim, kako se velike količine neprerađenih ili nepropisno prerađenih otpadnih voda ispuštaju u vodotokove teško je razdvojiti sanitarno od organskog zagađenja. Vizuelni prikaz rezultata IBR metodom pokazao se veoma korisnim u analizi međusobnih odnosa različitih biomarkera i ima široku primenu u biomonitoringu. Osim primene na biomarkerima, metoda može da pokaže i uzajamne odnose različitih hemijskih parametara. Metoda IBR do sada nije korišćena za analizu uzajamnih odnosa mikrobioloških parametara. CILJEVI: Primena IBR metode u proceni kvaliteta vode, pri čemu su mikrobiološki parametri fekalnog i organskog zagađenja korišćeni kao “biomarkeri“. METODE: Za potrebe ove studije odabrana su dva seta podataka. Prvi set je dobijen tokom višemesečnog monitoringa na reci Savi tokom 2014. godine, uključujući i period sa poplavom, tj. maj mesec. Od indikatora fekalnog zagađenja praćeni su totalni koliformi, Escherichia coli, Enterococcus faecalis i Clostridium perfringens. Nivo organskog zagađenja određen je na osnovu odnosa heterotrofnih i oligotrofnih bakterija, i indeksa fosfatazne aktivnosti. Drugi set podataka dobijen je tokom višemesečnog monitoringa sezonskog variranja mikrobioloških indikatora na reci Peštan, tokom 2012. godine. Od indikatora fekalnog zagađenja praćeni su totalni koliformi, E. coli i E. faecalis. Nivo organskog zagađenja određen je na osnovu odnosa heterotrofnih i oligotrofnih bakterija. REZULTATI: Vizuelni prikaz rezultata IBR metodom dao je jasan uvid u minimalne i maksimalne vrednosti svakog od indikatora fekalnog i organskog zagađenja tokom različitih meseci. Za prvi set podataka, na osnovu grafika i na osnovu dobijenih IBR vrednosti, jasno se izdvaja mesec u kome je došlo do poplava. Za drugi set podataka očigledno je variranje mikrobioloških parametara tokom različitih sezona. ZAKLJUČAK: Metoda IBR je pogodna za prikaz i analizu kompleksnog seta mikrobioloških podataka

Uticaj poplava na mikrobiološki kvalitet vode reke Save na teritoriji grada Obrenovca

U ovom istraživanju praćen je mikrobiološki kvalitet vode reke Save, na lokalitetu nizvodno od grada Obrenovca, pre i nakon velikih poplava koje su se dogodile u maju 2014. godine. Praćeni su indikatori fekalnog zagađenja (ukupni koliformi, Escherichia coli, Enterococcus faecalis) kao i pokazatelji organskog opterećenja (heterotrofi). Dobijeni rezultati pokazuju da je tokom meseca sa najvišim vodostajem (maj) došlo do velikog pada u koncentraciji glavnih pokazatelja fekalnog zagađenja, u prvom redu E. coli. Sa porastom vodostaja tokom perioda poplava uočen je i pad koncentracije heterotrofnih bakterija. S druge strane, detektovan je porast koncentracije ukupnih koliforma tokom poplava. U ovom ispitivanju jasno je pokazano da poplave dovode do promena u trendu variranja koncentracija mikrobioloških parametara kvaliteta vode

The Joint Danube Survey 3: Usage of freshwater mussels as bioindicators for detection of the genotoxic pollution

The Joint Danube Survey 3 (JDS3) was the world‟s biggest river research expedition of its kind in 2013. JDS3 catalyzes international cooperation from all 14 of the main Danube Basin countries and the European Commission. The JDS is carried out every six years – JDS1 was in 2001 and JDS2 in 2007. During the JDS3 we assessed the level of genotoxic pollution along the Danube River by measuring the level of DNA damage in the haemocytes of freshwater mussels of Unio sp. and Sinanodonta woodiana with comet assay. The research was performed on 34 out of 68 sites analysed within the JDS3. During research, 2,285 river kilometres were covered with an average distance of 68 km between the sites. The complex data set on concentrations of various substances present in water, suspended particulate matter and sediment on investigated sites gave the opportunity to identify the groups of xenobiotics which mostly affect the studied biomarker – DNA damage. The highest levels of DNA damage were recorded in the section VI (Panonnian Plain), which is under the impact of untreated wastewater discharges. Both positive and negative influence of the large tributaries on the level of genotoxicity in the Danube River was evident. Significant correlation in response was detected between the studied freshwater mussels. The level of DNA damage in mussels correlated with concentrations of compounds from the group of hazardous priority substances (polycyclic aromatic hydrocarbons), persistent organic pollutants (dioxins) and emerging pollutants (Oxazepam, Chloridazon-desphenyl)