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

The Lamb shift in muonic hydrogen

The long quest for a measurement of the Lamb shift in muonic hydrogen is over. Last year we measured the 2S1/2F=1–2P3/2F=2 energy splitting (Pohl et al., Nature, 466, 213 (2010)) in μp with an experimental accuracy of 15 ppm, twice better than our proposed goal. Using current QED calculations of the fine, hyperfine, QED, and finite size contributions, we obtain a root-mean-square proton charge radius of rp = 0.841 84 (67) fm. This value is 10 times more precise, but 5 standard deviations smaller, than the 2006 CODATA value of rp. The origin of this discrepancy is not known. Our measurement, together with precise measurements of the 1S–2S transition in regular hydrogen and deuterium, gives improved values of the Rydberg constant, R∞ = 10 973 731.568 160 (16) m⁻¹ and the rms charge radius of the deuteron rd = 2.128 09 (31) fm

Larval dietary protein complexity affects the regulation of muscle growth and the expression of DNA methyltransferases in Senegalese sole

Author's accepted version (post-print).Available from 28/02/2020.acceptedVersio