Molecular regulation of muscle development and growth in Senegalese sole larvae exposed to temperature fluctuations

Author's accepted version (post-print).NOTICE: this is the author’s version of a work that was accepted for publication in Aquaculture (2014). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Aquaculture (2014), 432. doi: http://dx.doi.org/10.1016/j.aquaculture.2014.04.035.The Senegalese sole (Solea senegalensis) is a marine flatfish that is naturally exposed to high temperature fluctuations (12 - 28 ºC) in the wild, with a life cycle predominantly estuarine during larval and juvenile phases. Farming of this species has largely improved in the past years but marked fluctuations of temperature during production still contribute to variation on growth and muscle cellularity, particularly if they occur during early stages of development. Such thermal plasticity of muscle growth must arise through changes in a multitude of physiological and molecular pathways, in which epigenetic gene regulation is likely to play an essential role. In the present work, we review recent studies addressing molecular, physiological and morphological aspects of the thermal plasticity of somatic growth in Senegalese sole larvae and early juveniles, thus aiming to improve sole rearing in aquaculture production. The present study shows that temperature during specific time frames of ontogeny has both short- and long-term effects on growth and muscle cellularity of Senegalese sole. Nevertheless, Senegalese sole also seems to rapidly adapt to environmental temperature through a set of epigenetic mechanisms and physiological responses such as regulation of feed intake, even at early developmental stages

Plant protein blends in diets for Senegalese sole affect skeletal muscle growth, flesh texture and the expression of related genes

Author's accepted version (postprint).Available from 26/11/2017.Skeletal muscle growth and flesh quality of Senegalese sole fed diets containing increasing levels of plant protein blends to replace fishmeal were evaluated using muscle cellularity, texture profile and gene expression. A control fish meal-based diet (FM) was compared with three isonitrogenous (54%) and isolipidic (9%) diets with increasing levels of plant protein (PP) blends (50% PP50, 75% PP75 and 100% PP100). By the end of the experiment sole fed PP50 and PP75 had a final body length similar to the CTR (25 cm), but fish fed PP100 were significantly smaller (23 cm). Total FM replacement by PP sources resulted in significantly smaller muscle cross sectional area (CSA) mainly due to a decrease in the muscle fibre size as the total number of fibres did not vary significantly among treatments. The dietary incorporation of PP significantly reduced the expression of several key genes involved in myogenesis and muscle growth (mrf4, fgf6, myhc and mylc2). Fillet texture analysed instrumentally was affected by the total substitution of FM. Fish fed PP100 diet had a significantly higher modulus of elasticity, i.e. lower flesh stiffness, compared with the other groups. Muscle fibre size was moderately related (r = − 0.573) to the modulus of elasticity and positively correlated with the expression of lysyl oxidase (r = 0.495). The observed changes in muscle cellularity could not be associated with the expression of texture-related genes (capn2, ctsb, ctsd), since no significant differences were observed among diets. The present results point towards a modulation of the expression of several muscle growth related genes by increasing levels of PP sources that alter muscle cellularity and textural properties of Senegalese sole when total FM is replaced by PP

Approaches to improve utilization of Nannochloropsis oceanica in plant-based feeds for Atlantic salmon

Rigid cell walls of microalgae lower the digestibility and nutrient bioavailability in carnivorous fish. Extrusion is a thermo-mechanical process and a scalable technology that may break cell walls and improves nutrient utilization. It can be hypothesized that certain feed additives may further improve microalgae nutrient digestibility and feed utilization by fish. The aim of the current study was to investigate i) the effect of incorporation of 10% pre-extruded Nannochloropsis oceanica on nutrient digestibility, growth and feed utilization of Atlantic salmon post smolts, and ii) the ability of feed additives in improving the feed utilization. Four low fish meal feeds were formulated; a control without the microalga N. oceanica (CO), a feed containing 10% of the pre-extruded microalga (NC), and two feeds containing 10% of the pre-extruded microalga and supplemented with either 0.06% Digestarom® (ND) or 1% ZEOFeed (NZ). Fish (initial average weight of 227.3 ± 3.4 g) in 5 replicate tanks of each of the study groups were fed one of the experimental feeds for 68 days. The apparent digestibility of dry matter in the NC and NZ groups were significantly higher compared to the control group (CO). The digestibility of lipid was significantly lower, and digestibility of ash was higher in the alga-fed groups (NC, ND and NZ) compared to the control group (CO). The incorporation of 10% pre-extruded N. oceanica in plant-based commercial-like feeds did not affect the growth, feed utilization and whole body proximate composition of salmon. No effects of the feed additives were observed on growth, feed utilization and histomorphology of distal intestine of salmon, but cell proliferation (PCNA) was higher for fish fed the alga alone as well as the alga-ZEOfeed combination. There were no differences in polyunsaturated fatty acids in whole body of fish fed the different feeds. It is noteworthy that whole-body EPA + DHA levels of fish fed the algae feeds were maintained at the same levels as fish fed the control feed that contained 50% more fish meal and 10% more fish oil.publishedVersionUnit Licence Agreemen

Changes in intestinal microbiota, immune- and stress-related transcript levels in Senegalese sole (Solea senegalensis) fed plant ingredient diets intercropped with probiotics or immunostimulants

Author's accepted version (post-print).Available from 04/03/2018.Senegalese sole (Solea senegalensis) is a highly valued flatfish that grows well with diets containing plant ingredients but their effects on immune competence is still a matter of debate. The current study aimed to examine changes in innate immune parameters and gut microbiota in Senegalese sole fed with 35% or 72% of plant ingredients with or without probiotic or yeast supplementation. Overall, fish fed diets with 72% of plant ingredients showed lower transcript levels of key immune- and stress-related genes in distal intestine, rectum and head-kidney than the 35% diets. In particular, hsp90b mRNA levels in distal intestine were down-regulated by 70% and 60% with the use of high content of plant ingredients in the diet containing the multispecies probiotic and autolyzed yeast, respectively. Denaturing gradient gel electrophoresis showed lower similarity values for distal intestine than rectum. Also fish fed high content of plant ingredients displayed lower similarity values, pointing to a difference in the microbial populations between fish fed different plant ingredients content on the diet. Our data revealed that inclusion of plant ingredients was associated with differences in gene expression and a more diverse microbiota profile but without a significant effect on growth performance. Moreover, probiotic supplementation resulted in up-regulation of hsp90b, gpx, cat and apoa1 transcript levels in distal intestine concomitantly with a growth rate reduction compared to non-supplemented fish

Effects of dietary curcumin in growth performance, oxidative status and gut morphometry and function of gilthead seabream postlarvae

An imbalance in the production and detoxification of reactive oxygen species and other oxidants can disrupt a l l types of cellular compounds, and lead to a state of oxidative stress. Preventing this state is essential to improve growth and health in animal production. Therefore, the aim of this work was to assess i f the dieta r y supple-mentation of curcumin cou l d improve the antioxidant status and intestine structu r e and functionalit y of gilthead seabream postlarvae, with the global objective of improving fish growth performance and robustness. Two experimental diets supplemented with different doses of curcumin (LOW and HIGH diets), and a commercial diet were fed to quadruplicate groups of postlarvae, for 20 days. At the end of the feeding trial fish fed the supple-mented diets significantly improved their antioxidant status compared to CTRL fed fish. LOW and HIGH fed fish presented lower protein oxidative damage (P 0.05). In conclusion, dieta r y curcumin supplementation was able to enhance gilthead seabream postlarvae robustness through a modulation of the oxidative status, increasing total antioxidant capacity and decreasing protein oxidative damage. This data pro-vide evidence that curcumin can be a suitable feed additive to promote heath status and robustness of fish at early stages of development, therefore contributing for the development and sustainabilit y of marine fish hatchery production.info:eu-repo/semantics/publishedVersio

Comparative analysis between synthetic vitamin E and natural antioxidant sources from tomato, carrot and coriander in diets for market-sized dicentrarchus labrax

Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers’ preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg−1) or reinforced dose (VITE; 500 mg kg−1). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg−1 of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg−1 of vitamin E.info:eu-repo/semantics/publishedVersio

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters