Plasma proteome profiling of freshwater and seawater life stages of rainbow trout (Oncorhynchus mykiss)

The sea-run phenotype of rainbow trout (Oncorhynchus mykiss), like other anadromous salmonids, present a juvenile stage fully adapted to life in freshwater known as parr. Development in freshwater is followed by the smolt stage, where preadaptations needed for seawater life are developed making fish ready to migrate to the ocean, after which event they become post-smolts. While these three life stages have been studied using a variety of approaches, proteomics has never been used for such purpose. The present study characterised the blood plasma proteome of parr, smolt and post-smolt rainbow trout using a gel electrophoresis liquid chromatography tandem mass spectrometry approach alone or in combination with low-abundant protein enrichment technology (combinatorial peptide ligand library). In total, 1,822 proteins were quantified, 17.95% of them being detected only in plasma post enrichment. Across all life stages, the most abundant proteins were ankyrin-2, DNA primase large subunit, actin, serum albumin, apolipoproteins, hemoglobin subunits, hemopexin-like proteins and complement C3. When comparing the different life stages, 17 proteins involved in mechanisms to cope with hyperosmotic stress and retinal changes, as well as the downregulation of nonessential processes in smolts, were significantly different between parr and smolt samples. On the other hand, 11 proteins related to increased growth in post-smolts, and also related to coping with hyperosmotic stress and to retinal changes, were significantly different between smolt and post-smolt samples. Overall, this study presents a series of proteins with the potential to complement current seawater-readiness assessment tests in rainbow trout, which can be measured non-lethally in an easily accessible biofluid. Furthermore, this study represents a first in-depth characterisation of the rainbow trout blood plasma proteome, having considered three life stages of the fish and used both fractionation alone or in combination with enrichment methods to increase protein detection

Effects of different photoperiod regimes on the smoltification and seawater adaptation of seawater-farmed rainbow trout (Oncorhynchus mykiss): Insights from Na+, K+-ATPase activity and transcription of osmoregulation and growth regulation genes

Photoperiod is thought to be the main zeitgeber that induces smoltification in salmonids. However, its effects on the smoltification of rainbow trout (Oncorhynchus mykiss) are not fully understood and no published data documents the effects of the photoperiod regime currently used commercially, continuous light (LL). The present study compared the effect of four different photoperiod regimes (i.e. advanced phase photoperiod (APP), delayed phase photoperiod (DPP), LL and simulated natural photoperiod (SNP)) on the smoltification and growth of juvenile rainbow trout during their freshwater phase of winter-spring and the following summer post smolt phase. Smoltification was evaluated by monitoring gill Na+,K+–ATPase (NKA) activity and transcription of NKA α-subunit isoforms 1a and 1b, and Na+,K+,2Cl− cotransporter 1a. Growth was measured as specific growth rate of both length and weight, and through molecular growth proxies such as the levels of circulating insulin-like growth factor 1 (IGF-I) in plasma and transcription of igf-I, igf binding protein 1b (igfbp1b), growth hormone receptor 1 (ghr1) and cathepsin L (ctsl) in the liver. Results indicate that APP induces a longer smolt window and higher levels of plasma IGF-I in both freshwater and seawater (two months post transfer), while DPP led to a shorter smolt window, lower plasma IGF-I levels in freshwater and seawater, an earlier decrease in liver igf-I and ctsl transcription in freshwater (as seen by modelling over time) and lower specific growth rate in freshwater. The transcription analysis of osmoregulatory genes complemented NKA activity and allowed for the detection of a transient response to light and of differences between the osmoregulatory capacity of parr and desmolted fish. Furthermore, an upregulation of the liver transcription of igf-I, ghr1 and ctsl was found in all treatments during the smolt window, which corresponded to the periods with highest growth. Finally, both plasma IGF-I and liver igf-I in seawater were found to be significantly correlated to fish growth in seawater. However, our data did not show that plasma IGF-I prior to seawater transfer could be used as a reliable predictor of growth in seawater. Overall, and especially when compared with other salmonid species, photoperiod seems to be a weaker inducer of smoltification in rainbow trout, according to the parameters that were tested, suggesting that other environmental cues might be more important drivers of this process

Effects of temperature and photoperiod on rainbow trout (Oncorhynchus mykiss) smoltification and haematopoiesis

First paragraph: Most freshwater fish would not be able to cope with the osmotic stress intrinsic to seawater, quickly dehydrating and dying, and so are bound to freshwater ecosystems (Quinn et al., 2016). However, anadromous salmonids have developed a strategy to minimize osmotic counter effects, thus allowing them to live in both freshwater, ideal for safe spawning, hatching and early growth stages, and seawater environments, rich in energy resources for fast growth (Hendry et al., 2004; Lima and Dill, 1990)

ANALISIS KEMAMPUAN BERFIKIR ALJABAR DI KELAS VII SMP NEGERI 1 KRANGKENG KABUPATEN INDRAMAYU (Studi Survei di Kelas VII Tahun Akademik 2012/2013)

Setiati Rahayu, 2013. Analisis Kemampuan Berfikir Aljabar di Kelas VII di SMP Negeri 1 Krangkeng Kab. Indramayu (Studi Survei di Kelas VII Tahun Akademik 2012/2013) Untuk mengukur kemampuan berfikir aljabar seorang siswa diperlukan beberapa indikator. Terdapat beberapa indikator untuk memahami aljabar diantaranya memahami pengertian koefisien variabel suku sejenis, kemampuan melakuakan operasi hitung, kemampuan mengggunakan simbol matematika, kemampuan menggunakan bahasa sehari-hari, kemampuan menyederhanakan operasi aljabar, kemampuan menyatakan berbagai hubungan, kemampuan menggunakan diagram alur dan memahami konsep aljabar invers. Tujuan dalam penelitian ini untuk menganalisis kemampuan berfikir aljabar di kelas VII yang ditinjau dari operasi aljabar, penggunaan aljabar, masalah aljabar, dan pemahaman konsep aljabar saat menjawab soal-soal aljabar. Kemampuan siswa dalam memahami aljabar merupakan suatu kondisi yang terdapat dalam sekolah SMP tersebut. Aljabar adalah suatu cabang ilmu matematika yang menggunakan tandatanda dan huruf-huruf yang mewakili angka-angka. Banyaknya indikator yang menjadi indikator kemampuan aljabar, maka akan ada beberapa indikator yang akan menjadi komponen utama dalam kemampuan aljabar. Untuk mengetahui kemampuan siswa dalam memahami aljabar, tidak perlu semua indikator pada\ud materi aljabar diujikan dalam tes. Mengetahui sangat pentingnya komponen utama dalam materi aljabar untuk mengukur kemampuan berfikir aljabar seorang siswa maka peneliti mencoba menganalisis kemampuan berfikir aljabar siswa kelas VII di SMPN 1 Krangkeng. Teknik pengumpulan data yang digunakan dalam penelitian ini adalah tes. Populasi dalam penelitian ini adalah Kelas VII yang berjumlah (160 siswa). Sampel diambil dari kelas VIIB cluster random sampling. Untuk uji coba dilakukan di kelas VIIA yang berjumlah 32. Dari hasil penelitian diperoleh hasil sebagai berikut: 1) Aljabar di SMP N 1 Krangkeng cukup baik hal ini ditunjukan dengan nilai rata-rata 75. 2) Indikator kemampuan berfikir aljabar secara mekanisme dan indikator Kemampuan terbesar yang dicapai oleh siswa kelas VII SMP Negeri 1 Krangkeng tahun ajaran 2012/2013 dalam memahami aljabar adalah pada pengertian koefisien, variabel, konstanta, faktor, suku sejenis adalah sebesar 89.58% dan kemampuan yang kurang dikuasai oleh siswa kelas VII SMP Negeri 1 Krangkeng tahun ajaran 2012/2013 dalam memahami aljabar adalah memahami invers adalah sebesar 85.94%. 3) Dari delapan indicator kemampuan berfikir aljabar ada tiga komponen yang dominan yaitu menggunakan diagram alur, pengertian koefisien variable konstanta, faktor suku sejenis, dan menyederhanakan operasi aljaba

Endoplasmic reticulum stress as a key mechanism in stunted growth of seawater rainbow trout (Oncorhynchus mykiss)

Background Rainbow trout (Oncorhynchus mykiss) is a salmonid species with a complex life-history. Wild populations are naturally divided into freshwater residents and sea-run migrants. Migrants undergo an energy-demanding adaptation for life in seawater, known as smoltification, while freshwater residents display these changes in an attenuated magnitude and rate. Despite this, in seawater rainbow trout farming all fish are transferred to seawater. Under these circumstances, weeks after seawater transfer, a significant portion of the fish die (around 10%) or experience growth stunting (GS; around 10%), which represents an important profitability and welfare issue. The underlying causes leading to GS in seawater-transferred rainbow trout remain unknown. In this study, we aimed at characterising the GS phenotype in seawater-transferred rainbow trout using untargeted and targeted approaches. To this end, the liver proteome (LC-MS/MS) and lipidome (LC-MS) of GS and fast-growing phenotypes were profiled to identify molecules and processes that are characteristic of the GS phenotype. Moreover, the transcription, abundance or activity of key proteins and hormones related to osmoregulation (Gill Na+, K + –ATPase activity), growth (plasma IGF-I, and liver igf1, igfbp1b, ghr1 and ctsl) and stress (plasma cortisol) were measured using targeted approaches. Results No differences in Gill Na+, K + –ATPase activity and plasma cortisol were detected between the two groups. However, a significant downregulation in plasma IGF-I and liver igf1 transcription pointed at this growth factor as an important pathomechanism for GS. Changes in the liver proteome revealed reactive-oxygen-species-mediated endoplasmic reticulum stress as a key mechanism underlying the GS phenotype. From the lipidomic analysis, key observations include a reduction in triacylglycerols and elevated amounts of cardiolipins, a characteristic lipid class associated with oxidative stress, in GS phenotype. Conclusion While the triggers to the activation of endoplasmic reticulum stress are still unknown, data from this study point towards a nutritional deficiency as an underlying driver of this phenotype

High fish density delays wound healing in Atlantic salmon (Salmo salar)

In this study, we look closer at how high fish densities influence wound repair mechanisms in post-smolt Atlantic salmon. The fish were wounded with a 5 mm skin punch biopsy needle and stocked at two different densities, a high fish density (100 kg/m3) treatment and a low fish density treatment (20 kg/m3) serving as the control. The healing wounds were followed for 57 days with samples taken 1, 3, 7, 14, 36, 43 and 57 days post wounding. The transcriptomic analysis suggests that high fish density enhance inflammation and represses cell proliferation, tissue secretion and collagen synthesis in the healing wounds. The histological analysis further showed delayed epidermal and dermal repair in the high fish density treatment compared to control. The overall wound contraction was also altered by the treatment. In conclusion, high fish density enhances immune responses and delay tissue repair, which ultimately results in delayed wound healing.High fish density delays wound healing in Atlantic salmon (Salmo salar)publishedVersio

Wound healing in post-smolt Atlantic salmon (Salmo salar L.)

publishedVersio

Atlantic salmon skin barrier functions gradually enhance after seawater transfer

publishedVersio

High fish density delays wound healing in Atlantic salmon (Salmo salar)

In this study, we look closer at how high fish densities influence wound repair mechanisms in post-smolt Atlantic salmon. The fish were wounded with a 5 mm skin punch biopsy needle and stocked at two different densities, a high fish density (100 kg/m3) treatment and a low fish density treatment (20 kg/m3) serving as the control. The healing wounds were followed for 57 days with samples taken 1, 3, 7, 14, 36, 43 and 57 days post wounding. The transcriptomic analysis suggests that high fish density enhance inflammation and represses cell proliferation, tissue secretion and collagen synthesis in the healing wounds. The histological analysis further showed delayed epidermal and dermal repair in the high fish density treatment compared to control. The overall wound contraction was also altered by the treatment. In conclusion, high fish density enhances immune responses and delay tissue repair, which ultimately results in delayed wound healing