On the diffusion constant of water in wheat

Diffusion-weighted magnetic resonance imaging (MRI) was used to obtain diffusion constants for water in the embryo and endosperm of wheat. Our experiments showed a significant difference between the diffusion constant for the two components. It was also shown that water diffusion in both the endosperm and embryo deviates from the typically observed Gaussian behavior in bulk fluids, showing a time-dependent diffusion constant. Diffusion constants for the embryo and endosperm were shown to differ by an order of magnitude. Using a model for restricted diffusion, information on the endosperm pore size and the embryo cell dimensions could be obtained.     

Synthesis and Antifouling Activity Evaluation of Analogs of Bromosphaerol,a Brominated Diterpene Isolated from the Red Alga Sphaerococcus coronopifolius

Marine biofouling is an epibiotic biological process that affects almost any kind of submerged surface, causing globally significant economic problems mainly for the shipping industry and aquaculture companies, and its prevention so far has been associated with adverse environmental effects for non-target organisms. Previously, we have identified bromosphaerol (1), a brominated diterpene isolated from the red alga Sphaerococcus coronopifolius, as a promising agent with significant antifouling activity, exerting strong anti-settlement activity against larvae of Amphibalanus (Balanus) amphitrite and very low toxicity. The significant antifouling activity and low toxicity of bromosphaerol (1) motivated us to explore its chemistry, aiming to optimize its antifouling potential through the preparation of a number of analogs. Following different synthetic routes, we successfully synthesized 15 structural analogs (2–16) of bromosphaerol (1), decorated with different functional groups. The anti-settlement activity (EC₅₀) and the degree of toxicity (LC₅₀) of the bromosphaerol derivatives were evaluated using cyprids and nauplii of the cirriped crustacean A. amphitrite as a model organism. Derivatives 2, 4, and 6–16 showed diverse levels of antifouling activity. Among them, compounds 9 and 13 can be considered as well-performing antifoulants, exerting their activity through a non-toxic mechanism.     

Proteomic profiling of sea bass muscle by two-dimensional gel electrophoresis and tandem mass spectrometry

In this study, the proteome profile of European sea bass (Dicentrarchus labrax) muscle was analyzed using two-dimensional electrophoresis (2-DE) and tandem mass spectrometry with the aim of providing a more detailed characterization of its specific protein expression profile. A highly populated and well-resolved 2-DE map of the sea bass muscle tissue was generated, and the corresponding protein identity was provided for a total of 49 abundant protein spots. Upon Ingenuity Pathway Analysis, the proteins mapped in the sea bass muscle profile were mostly related to glycolysis and to the muscle myofibril structure, together with other biological activities crucial to fish muscle metabolism and contraction, and therefore to fish locomotor performance. The data presented in this work provide important and novel information on the sea bass muscle tissue-specific protein expression, which can be useful for future studies aimed to improve seafood traceability, food safety/risk management and authentication analysis. This work is also important for understanding the proteome map of the sea bass toward establishing the animal as a potential model for muscular studies.     

Single nucleotide polymorphisms in the growth hormone gene of Oreochromis niloticus and their association with growth performance

Polymorphisms in the growth hormone (GH) gene that is associated with the growth rate of farmed fish have been the target of many breeding programmes. The present study aimed to identify single nucleotide polymorphisms (SNPs) in GH gene regions to evaluate the association of SNP variations with the growth rate of two Nile tilapia: Oreochromis niloticus (Linnaeus, 1758) strains. The targeted regions were amplified, sequenced, aligned and screened for the presence of SNPs; thereafter, performance tests were used to check for the association between SNPs and weight. Allele and genotype frequencies were estimated for each SNP and genotype. Genotype blocks or sets of SNP genotypes and frequencies were also estimated. Association between SNPs and growth rate was statistically evaluated using a univariate linear mixed model that included both fixed and random effects. A total of 10 SNPs were identified, nine in the proximal promoter and one located in the 5′ UTR, forming 10 genotype blocks. In all weight recordings, five genotype blocks were significantly associated with the highest weights. Single nucleotide polymorphisms 6‐10 were also found to be significantly associated with growth (p‐value < .05). Genotypes with higher additive genetic values for weight were identified in the Chitralada strain, suggesting a possible impact of these additive effects of the GH SNP genotype on the growth rate of Nile tilapia. These findings may be used as part of marker‐assisted selection in tilapia breeding programmes.     

Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights

1. The Juan Fernandez Ridge, a vulnerable marine ecosystem located far off the coast of central Chile and formed by several seamounts, guyots and three islands (Robinson Crusoe, Santa Clara and Alejandro Selkirk), has recently been declared a Coastal Marine Protected Area of Multiple Uses with several National Parks embedded in it.
2. Recent studies have highlighted the influence of remote and local oceanographic structures on the hydrographic dynamics of this ridge. However, there is still a gap in understanding how they affect the structure and dynamics of the surrounding insular planktonic communities.
3. A hydroacoustic and oceanographic survey was conducted during the austral spring (October 2016), including hydrographic and zooplankton sampling around Robinson Crusoe Island. Oceanographic features were identified and tracked using satellite data (chlorophyll-a (Chl-a) and sea surface temperature) and modelling results.
4. Two events of Chl-a increase relative to a threshold (>0.45 mg m⁻³) were forced by different physical processes, both affecting the western side of Robinson Crusoe Island. In event A during the cruise period, Chl-a subsurface maxima were associated with the arrival of a coastal meander originating on the continental shelf off Chile (remote process); the zooplankton was dominated by copepods and salps, with an evident coastal–oceanic gradient. In event B, Chl-a maxima were linked to a local upwelling forced by the intensification of a localized SSW wind. No influence of remote eddies or local Von Kármán vortices on Chl-a distribution was observed.
5. These findings highlight the influence of remote and local physical processes on the structure of planktonic communities around Robinson Crusoe Island. Understanding the variability of these mechanisms and their effects at the base of the pelagic food web is critical in adopting an ecosystem-level approach.

     

Evaluation of different protein sources in fingerling grey mullet <Emphasis Type="Italic">Mugil cephalus</Emphasis> practical diets

An eight-week experiment was carried out to evaluate the effects of different protein sources (fish and haemoglobin meal, soybean meal and torula yeast), in practical diets, on growth, body composition and gut morphology of fingerling grey mullet (Mugil cephalus). Weight gain (%), SGR, FCR, N retention, PER, PGR, FDR and carcass composition of fish were not significantly affected by the dietary protein source. Fish fed the torula yeast based diet showed reduction in growth performance. Histological examinations performed on the alimentary tract of the fish showed a normal structural pattern in the experimental groups, as fundamental histological and histochemical aspects were similar if compared to the control group. The lower growth performance observed in fish fed a torula yeast based diet may be tentatively correlated with the presence of some detrimental morpho-functional aspects in the gut of these fish if compared to fish fed the other diets. Further studies are necessary to confirm this hypothesis.     

Genetic and antigenic characterization of the surface lipoprotein P48 of Mycoplasma bovis

The presence of a membrane lipoprotein homologous to the P48 of Mycoplasma agalactiae was investigated in different Mycoplasma bovis isolates selected by geographical locations and biological properties. Its potential as a diagnostic tool was also discussed. The presence of a specific signal observed in all M. bovis field isolates probed with a rabbit antiserum raised against the M. agalactiae recombinant P48 demonstrated that this protein is structurally and antigenically conserved within the M. bovis cluster. No signal was detected when testing six different mycoplasma species found in cattle. The p48 gene was identified by PCR approach and partially sequenced. Full length gene sequence was obtained by direct bacterial chromosome sequencing. Five UGAs were selectively mutated into UGG and the full length mutated gene, lacking the signal peptide, was cloned and expressed in Escherichia coli. The purified recombinant antigen (r-P48) was evaluated as a potential marker of infection using a panel of 86 well-characterized sera from experimentally and naturally infected cattle. Specific IgM antibodies were detected within 6-9 days after experimental infection followed by an IgG response lasting from the third/fourth week after contact. Although antibody titers were well below those observed in sheep or goats infected with M. agalactiae, results suggest that M. bovis r-P48 can be used as a specific marker of infection.     

Tenogenic induction of equine mesenchymal stem cells by means of growth factors and low-level laser technology

Tendons regenerate poorly due to a dense extracellular matrix and low cellularity. Cellular therapies aim to improve tendon repair using mesenchymal stem cells and tenocytes; however, a current limitation is the low proliferative potential of tenocytes in cases of severe trauma. The purpose of this study was to develop a method useful in veterinary medicine to improve the differentiation of Peripheral Blood equine mesenchymal stem cells (PB-MSCs) into tenocytes. PB-MSCs were used to study the effects of the addition of some growth factors (GFs) as TGFβ3 (transforming growth factor), EGF2 (Epidermal growth factor), bFGF2 (Fibroblast growth factor) and IGF-1 (insulin-like growth factor) in presence or without Low Level Laser Technology (LLLT) on the mRNA expression levels of genes important in the tenogenic induction as Early Growth Response Protein-1 (EGR1), Tenascin (TNC) and Decorin (DCN). The singular addition of GFs did not show any influence on the mRNA expression of tenogenic genes whereas the specific combinations that arrested cell proliferation in favour of differentiation were the following: bFGF2 + TGFβ3 and bFGF2 + TGFβ3 + LLLT. Indeed, the supplement of bFGF2 and TGFβ3 significantly upregulated the expression of Early Growth Response Protein-1 and Decorin, while the use of LLLT induced a significant increase of Tenascin C levels. In conclusion, the present study might furnish significant suggestions for developing an efficient approach for tenocyte induction since the external administration of bFGF2 and TGFβ3, along with LLLT, influences the differentiation of PB-MSCs towards the tenogenic fate.     

A century of fishery data documenting the collapse of smooth‐hounds (Mustelus spp.) in the Mediterranean Sea

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Demand feeding and welfare in farmed fish

Following the development of demand-feeding systems, many experiments have been conducted to explore feeding motivation and feed intake in farmed fish. This work aims to review a selection of studies in the field, focusing on three key factors, related to demand feeding and fish welfare. Firstly, we outline how demand feeders should be considered when developing feed management strategies for improving welfare in production conditions. Secondly, via laboratory demand-feeding experiments, we show self-feeding activities depend not only on feeding motivation and social organisation, but also on individual learning capacity and risk-taking behaviour. Thirdly, we report encouraging results demonstrating that when presented with two or more self-feeders containing complementary foods, fish select a diet according to their specific nutritional requirements, suggesting that demand feeders could be used to improve welfare by allowing fish to meet their nutritional needs.