The Senegalese sole (Solea senegalensis) is a marine flatfish that is naturally exposed to high temperature fluctuations (12–28ºC) 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 molecular mechanisms and physiological responses such as regulation of feed intake, even at early developmental stages.
•Egg incubation at 18ºC and larva transfer to 21ºC promote muscle hyperplasia.•Rearing pelagic larvae at 15ºC decreases protein absorption and survival.•Rearing pelagic larvae at 15ºC increases methylation of the myog promoter in muscle.•Muscle hyperplasia and hypertrophy are linked to the previous thermal history.
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•Electroanalysis of ecstasy (MDMA) using screen-printed carbon electrodes (SPCEs).•Molecularly imprinted polymers (MIPs) were developed for MDMA.•The polymerization of ...o-phenylenediamine (o-PD) and its interaction with MDMA was simulated by DFT methods.•The SPCE-MIP selectively analysed MDMA by square-wave voltammetry (SWV).•First time a SPCE-MIP sensor was developed for MDMA.
This study demonstrates the ability of an electrochemical sensor based on molecularly imprinted polymers (MIPs) to selectively quantify 3,4-methylenedioxymethamphetamine (MDMA), also known as ecstasy, in biological samples. The device was constructed using ortho-phenylenediamine (o-PD) as the MIP’s building monomer at the surface of a screen-printed carbon electrode (SPCE). The step-by-step construction of the SPCE-MIP sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Density functional theory (DFT) calculations and modelling were performed not only to understand template-monomer interaction but also to comprehend which possible polymer structure - linear or ramified poly(o-PD) – indeed interacts with the analyte. The prepared sensor worked by directly measuring the MDMA oxidation signal through square-wave voltammetry (SWV) after an incubation period of 10 min. Several parameters were optimized, such as the monomer/template ratio, the number of electropolymerization scanning cycles, and the incubation period, to obtain the best sensing efficiency. Optimized sensors exhibited suitable selectivity, repeatability (2.6%), reproducibility (7.7%) and up to one month of stable response. A linear range up to 0.2 mmol L−1 was found with an r2 of 0.9990 and a limit of detection (LOD) and quantification (LOQ) of 0.79 and 2.6 μmol L−1 (0.15 and 0.51 μg mL−1), respectively. The proposed sensor was successfully applied to human blood serum and urine samples, showing its potential for application in medicine and in forensic sciences.
Abstract The Corubal (Guinea-Bissau) is a wild but underexplored river in West Africa. This study underscores the potential of environmental DNA (eDNA) surveys to fill biodiversity knowledge gaps in ...the region. We filtered large water volumes at 11 sites along the watershed, amplified multiple molecular markers, and performed high PCR (polymerase chain reaction) replication and in-depth sequencing. We recorded 2589 amplicon sequence variants, with accumulation curves indicating the need for additional sampling to achieve a thorough survey. The taxonomic assignments were constrained by the scarcity of genomic resources. We recorded 125 species of aquatic and terrestrial vertebrates, including 21 new to the country, predominantly fish (61.9%). Surprisingly, crocodiles were not detected, despite their known presence. There were 11 imperiled species, two of which are Critically Endangered (Western chimpanzee and the mussel Pleiodon ovatus). Our findings support the conservation importance of the Corubal, provide a baseline for future monitoring, and highlight the challenges and opportunities of eDNA surveys in remote tropical rivers.
Reach-through avalanche photodiodes (RT-APDs) from Hamamatsu Photonics, with different active areas, 5 × 5 and 3 × 3 mm 2 , were investigated to evaluate their suitability for the muonic helium Lamb ...shift experiment. The gain has been determined as a function of voltage and temperature for both prototypes. As expected, it increases with increasing bias voltage and with decreasing temperature. The gain variation with temperature is smaller than per -2% °C even for higher bias voltages applied to the RT-APD. The non-linearity between gain obtained for X-rays and visible light pulses has been investigated for different temperatures. The non-linearity was found to increase with decreasing temperature. For example at 350 V, it is as high as 25% at -20 °C and about 10% at 20 °C. The RT-APDs performance for the detection of 8 keV X-rays has been investigated. The best energy resolution was achieved for the larger prototype for a temperature of 0 °C. The minimum energy resolution values, between 9.2 and 9.9%, were obtained for gains between 55 and 80. The minimum detectable energy observed is about 0.2 keV for the higher gain region, for both RT-APDs, investigated, with no significant improvement at lower temperatures.
The full expression of growth potential in fish larvae largely depends on an efficient protein utilization, which requires that all the indispensable amino acids (IAAs) are provided at an optimum ...ratio. The effect of supplementing a practical microdiet with encapsulated crystalline-AA to correct possible IAA deficiencies was evaluated in Senegalese sole larvae. Two isonitrogenous and isoenergetic microdiets were formulated and processed to have approximately the same ingredients and proximate composition. The control diet (CTRL) was based on protein sources commonly used in the aquafeed industry. In the supplemented diet (SUP) 8% of an encapsulated fish protein hydrolysate was replaced by crystalline-AA in order to increase the dietary IAA levels. The microdiets were delivered from mouth-opening upon a co-feeding regime until 51days after hatching (DAH). The larvae capacity to utilize protein was evaluated using an in vivo method of controlled tube-feeding during relevant stages throughout development: pre-metamorphosis (13DAH); metamorphosis climax (19DAH) and metamorphosis completion (25DAH). Somatic growth was monitored during the whole trial. A possible effect on the regulation of muscle growth was evaluated through muscle cellularity and the expression of related genes (myf5, myod2, myogenin, mrf4, myhc and mstn1) at metamorphosis climax (19DAH) and at a juvenile stage (51DAH). The SUP diet had a negative impact on larvae somatic growth after the metamorphosis, even though it had no effect on the development of Senegalese sole larvae capacity to retain protein. Instead, changes in somatic growth may reflect alterations on muscle growth regulation, since muscle cellularity suggested delayed muscle development in the SUP group at 51DAH. Transcript levels of key genes regulating myogenesis changed between groups, during the metamorphosis climax and at the 51DAH. The group fed the SUP diet had lower dnmt3b mRNA levels compared to the CTRL group. Further studies are needed to ascertain whether this would possibly lead to an overall DNA hypomethylation in skeletal muscle.
In farmed fish species, there has been a great effort over the years to provide the best conditions for successful development of embryos and small larvae, as early environmental conditions can strongly affect muscle growth during early stages and influence the subsequent growth potential at later life stages. In spite of increased efforts to understand the regulation of myogenesis by intrinsic factors like genotype and extrinsic factors such as photoperiod and temperature, studies evaluating the impact of nutritional factors on fish larvae muscle development are still very scarce.
This work will raise interest to the discussion on whether a nutritional cue during an early developmental stage can impact on the regulation of muscle growth and on further growth potential in a metamorphosing farmed fish species, such as Senegalese sole. Supplementing microdiets with crystalline-AA in order to correct dietary IAA did not improve Senegalese sole larvae somatic growth and led to changes on the regulation of muscle growth associated with changes in expression patterns of muscle growth markers during the trial (secondary MRFs myogenin and mrf4, myhc and mstn1). Dietary IAA affected the expression of a DNA methyltransferase essential for de novo methylation, dnmt3b, suggesting that an epigenetic effect at the transcriptional regulation level may explain differences found in somatic growth as a response to a nutritional cue.
This work may contribute to lay down basis for future studies on nutritional programming of muscle growth in fish larvae of important farmed species.
•Early life nutrition affects growth potential of a metamorphosing farmed fish species.•Dietary amino-acid profile affects the regulation of muscle growth in senegalese sole larvae.•Transcript levels of key genes regulating myogenesis changed with dietary IAA profiles.•Dietary IAA affected the expression of dnmt3b suggesting an epigenetic event underlying growth changes.•Our results lay down basis for future nutritional programming studies on fish larvae growth.
The present work examined the short- and long-term effects of three rearing temperatures on protein metabolism and growth trajectories of Senegalese sole larvae using ¹⁴C-labelled Artemia protein as ...feed. A first feeding trial was performed on larvae reared at 15, 18 and 21 °C (at 26, 17 and 14 days post-hatching (dph), respectively) and a second trial conducted on post-larvae after transfer to the same rearing temperature (~20 °C) (49, 35 and 27 dph, in larvae initially reared at 15, 18 and 21 °C, respectively). Temperature greatly influenced larvae relative growth rate (RGR) and survival, since growth at 15 °C was severely depressed. Protein digestibility and retention was highest at 18 °C during the first trial (85.35 ± 1.16 and 86.34 ± 2.33 %, respectively). However, during the second trial, post-larvae from 15 °C had the highest feed intake and protein digestibility (3.58 ± 1.54 and 75.50 ± 1.35 %, respectively), although retention was similar between treatments. Furthermore, after transfer to 20 °C larvae from 15 °C experienced compensatory growth, which was observed until 121 dph, and confirmed by RGR values, which were significantly higher at 15 ºC than at 21 ºC or 18 ºC. Results from the present study show that Solea senegalensis larval development, survival and protein digestion and retention are highly affected by thermal history.
The present study evaluates the long term (5months) effects of feeding vegetable oil-based diets to Senegalese sole (Solea senegalensis) until market size. Extruded isonitrogenous and isoenergetic ...diets (56% crude protein and 20kJ/g) were formulated to substitute 0 (CTRL), 50 (VO50) and 100% (VO100) of FO by a VO blend (rapeseed oil, RO, soybean oil, SO, and linseed oil, LO). A concomitant replacement of 50% FM and FO (VO50PP50) by plant protein sources (pea, soybean meal, potato concentrate, corn and wheat gluten) and oils was also evaluated. After the growth trial (140days), fish were fed a fish oil-based diet (CTRL) over a period of 26days and growth, flesh quality and organoleptic properties were determined.
Results show that it seems possible to substitute up to 100% of FO by a VO blend, as well as concomitantly substituting 50% FO and FM by vegetable sources in on-growing Senegalese sole diets, without compromising growth performance and feed utilization. This species selectively retains highly unsaturated fatty acids (ARA and DHA) and seems to adapt well to a low dietary supply of these FAs. At the end of the growth out experiment fish fed VO50 diet showed a similar n−3 HUFA profile to the CTRL fed fish. Total FO substitution resulted in a strong reduction of muscle EPA content that was totally recovered after 26days of re-feeding with a FO based diet. Despite the observed changes in fatty acid composition, sole fillets from fish fed 100% VO are very well accepted by fish consumers and still are good nutritional value end-products for human consumption, providing 1.5 times the RDI level (0.4g per 100g of muscle) of EPA+DHA.
•Total fish oil substitution does not impair growth or feed utilization.•Sole selectively retains highly unsaturated fatty acids (ARA and DHA).•Sole fillets fed high VO levels are well accepted by consumers.•Sole fillets fed high VO levels provide 1.5 times the RDI level of EPA+DHA.
Introduction
Cancer is a major public health problem with over 19 million cases reported in 2020. Similarly to humans, dogs are also largely affected by cancer, with non-Hodgkin's lymphoma (NHL) ...among the most common cancers in both species. Comparative medicine has the potential to accelerate the development of new therapeutic options in oncology by leveraging commonalities between diseases affecting both humans and animals. Within this context, in the present study, we investigated the potential of panobinostat (Pan)-loaded folate-targeted PEGylated liposomes (FA-PEG-Pan-Lip) for the treatment of canine B-cell lymphoma, while contributing to new perspectives in comparative oncology.
Methods and results
Two formulations were developed, namely: PEG-Pan-Lip and FA-PEG-Pan-Lip. Firstly, folate receptor expression in the CLBL-1 canine B-cell lymphoma cell line was assessed. After confirming receptor expression, both Pan-loaded formulations (PEG-Pan-Lip, FA-PEG-Pan-Lip) demonstrated dose-dependent inhibitory effects on CLBL-1 cell proliferation. The FA-PEG-Pan-Lip formulation (IC
50
= 10.9 ± 0.03 nM) showed higher cytotoxicity than the non-targeted PEG-Pan-Lip formulation (IC
50
= 12.9 ± 0.03 nM) and the free panobinostat (Pan) compound (IC
50
= 18.32±0.03 nM). Moreover, mechanistically, both Pan-containing formulations induced acetylation of H3 histone and apoptosis. Flow cytometry and immunofluorescence analysis of intracellular uptake of rhodamine-labeled liposome formulations in CLBL-1 cells confirmed cellular internalization of PEG-Lip and FA-PEG-Lip formulations and higher uptake profile for the latter. Biodistribution studies of both radiolabeled formulations in CD1 and SCID mice revealed a rapid clearance from the major organs and a 1.6-fold enhancement of tumor uptake at 24 h for
111
In-FA-PEG-Pan-Lip (2.2 ± 0.1 %ID/g of tumor) compared to
111
In-PEG-Pan-Lip formulation (1.2±0.2 %ID/g of tumor).
Discussion
In summary, our results provide new data validating Pan-loaded folate liposomes as a promising targeted drug delivery system for the treatment of canine B-cell lymphoma and open innovative perspectives for comparative oncology.
Dams provide water supply, flood protection, and hydropower generation benefits, but also harm native species by altering the natural flow regime, and degrading the aquatic and riparian habitats. In ...the present study, which comprised the Douro River basin located in the North of Portugal, the cost-benefit assessment of dams was based upon a balance between the touristic benefits of a dammed Douro, and the ecological benefits of less fragmented Douro sub-catchments. Focused on four sub-catchments (Sabor, Tâmega, Côa and Corgo), a probabilistic stream connectivity model was developed and implemented to recommend priorities for dam removal, where this action could significantly improve the movement of potadromous fish species along the local streams. The proposed model accounts for fish movement across the dam or weir (permeability), which is a novel issue in connectivity models. However, before any final recommendation on the fate of a dam or weir, the connectivity results will be balanced with other important socio-economic interests. While implementing the connectivity model, an inventory of barriers (dams and weirs) was accomplished through an observation of satellite images. Besides identification and location of any obstacles, the inventory comprised the compilation of data on surrounding land use, reservoir water use, characteristics of the riparian gallery, and permeability conditions for fish, among others. All this information was stored in a geospatial dataset that also included geographical information on the sub-catchment drainage network. The linear (drainage network) and point (barriers) source data were processed in a computer program that provided or returned numbers for inter-barrier stream lengths (habitat), and the barrier permeability. These numbers were finally used in the same computer program to calculate a habitat connector index, and a link improvement index, used to prioritize dam removal based upon structural connectivity criteria. The results showed that habitat patch connectivity in the Sabor, Tâmega and Côa sub-catchments is not dramatically affected by the installed obstacles, because most link improvement values were generally low. For the opposite reason, in the Corgo sub-catchment, obstacles may constitute a relatively higher limitation to connectivity, and in this case the removal of eight obstacles could significantly improve this connectivity. Using the probabilistic model of structural connectivity, it was possible to elaborate a preliminary selection of dams/weirs that critically limit stream connectivity, and that will be the focus of field hydraulic characterization to precisely determine fish movement along the associated river stretches. Future work will also include the implementation of a multi-criteria decision support system for dam removal or mitigation of the critical structures, as well to define exclusion areas for additional obstacles.
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