Only agouti-related protein 1 (agrp1) significantly responded, with increased expression in brains of starved fish. In contrast, a 21-day period of starvation significantly downregulated 466 and upregulated 108 transcripts in the liver, indicating an overall decrease in metabolic activity, reduced lipid metabolism, protein biosynthesis, proteolysis, and cellular respiration, and increased gluconeogenesis. Starvation also regulated expression of many components of the unfolded protein response, the first such report in a species other than yeast (Saccharomyces cerevisiae) and mice (Mus musculus). The response of the zebrafish hepatic transcriptome to starvation was strikingly similar to that of rainbow trout (Oncorhynchus mykiss) and less similar to mouse, while the response of common carp (Cyprinus carpio) differed considerably from the other three species. microarray analysis; metabolic signaling; quantitative real-time polymerase chain reaction; neuropeptide THE ADAPTIVE PHYSIOLOGICAL response to starvation conserves the health and function of key organs and redistributes resources toward essential biological functions. In mammals and birds, this reallocation of resources is part of a predictable and sequential transition of metabolic changes (reviewed in Ref. 72). These metabolic changes appear to be similar in fish and other ectotherms, although the transitions occur over a much longer time frame, largely the result of lower metabolic rates (72). Variation in metabolic rate in fish is in turn influenced by body size and body temperature (10, 29). As the most diverse group of vertebrates, fish species vary considerably in body size, thermal habitat, and metabolic rate, and many species differ in susceptibility or have unique adaptations to prolonged periods of fasting in their natural environment (37, 72). The considerable variation among fish species in the response to starvation provides a useful context for identifying mechanisms that are conserved among vertebrate species. Understanding these conserved mechanisms requires multiple investigations of a diverse array of species that identify the metabolic pathways that respond to starvation and genetic mechanisms that regulate them.Here we used microarrays and quantitative real-time PCR (qRT-PCR) to examine the transcriptomic response to starvation in both brain and liver tissues of adult female zebrafish (Danio rerio). The zebrafish is an important model organism for the study of development and is now emerging as a model organism in other fields, including behavioral, physiological, and nutritional genomics (42,49,76). Despite its importance as a developmental and genomic model organism, our understanding of the nutritional physiology of the zebrafish remains very limited. Our goal was to identify the metabolic pathways impacted by starvation in zebrafish, contrasting two organs that 1) serve biosynthetic and energy-mobilizing functions (liver) and 2) consume energy and direct behavioral responses (brain). In addition, we offer an interpretation of these d...

No abstract

The main goal of the present study was to address the effect of feeding fermented soybean meal-based diet to Atlantic salmon on gut microbiota. Further, expression of genes of interest, including cathelicidin antimicrobial peptide (cath), mucin 2 (muc2), aquaporin (aqp8ab), and proliferating cell nuclear antigen (pcna), in proximal intestine of fish fed either experimental diet was analyzed. Three experimental diets, including a control fishmeal (30% FM), soybean meal (30% SBM), or fermented soybean meal diet (30% FSBM) were randomly assigned to triplicate tanks during a 50-day trial. The PCR-TTGE showed microbiota composition was influenced by experimental diets. Bands corresponding to genus Lactobacillus and Pediococcus were characteristic in fish fed the FSBM-based diet. On the other hand, bands corresponding to Isoptericola, Cellulomonas, and Clostridium sensu stricto were only observed in fish FM-based diet, while Acinetobacter and Altererythrobacter were detected in fish fed SBM-based diet. The expression of muc2 and aqp8ab were significantly greater in fish fed the FSBM-based diet compared with the control group. Our results suggest feeding FSBM to Atlantic salmon may (1) boost health and growth physiology in fish by promoting intestinal lactic acid bacteria growth, having a prebiotic-like effect, (2) promote proximal intestine health by increasing mucin production, and (3) boost intestinal trans-cellular uptake of water. Further research to better understands the effects of bioactive compounds derived from the fermentation process of plant feedstuff on gut microbiota and the effects on health and growth in fish is required.

No abstract

No abstract

No abstract

A study was conducted to determine the benefits of the intake of purple corn extract (PCE), a natural source of anthocyanins, in rainbow trout, Oncorhynchus mykiss. A control or test diet supplemented with 5% PCE was fed to triplicate tanks with 25 fish each for 8 wk. The concentrations of three anthocyanins, cyanidin-3-glucoside, pelargonidin-3-glucoside, and peonidin-3-glucoside, were measured in PCE. The chemical composition and fatty acid profiles of fish, as well as the fatty acid profiles in plasma, liver, and muscle were determined. The total antioxidant capacity (TAC) and the concentration of oxidative damage biomarkers, for example, protein carbonyls, 8-hydroxydeoxyguanosine, and thiobarbituric acid reactive substances (TBARS), were determined in plasma. Transcription of two antioxidant enzymes, glutathione peroxidase 1 (gpx1) and superoxide dismutase 1 (sod1), was measured in erythrocytes. Significant lower adiposity and significant higher percentage of total n-3 and total n-6 polyunsaturated fatty acids (PUFA) in the body of fish fed the test diet were detected. Significant higher plasma percentage of total n-3 PUFA, significant higher plasma TAC, and significant higher expression of gpx1 in erythrocytes of fish fed the test diet were measured. Overall, our results suggest potential protection against in vivo lipid peroxidation in fish fed the PCE supplemented diet. This is especially true due to detection of an enhanced antioxidant protection in plasma and erythrocytes in fish, the reduced adiposity and greater proportion of total n-3 and n-6 PUFA in the fish body, as well as a tendency toward lower TBARS plasma concentration in fish fed the test diet when compared to the control group.

Artículo de publicación ISIRed macroalgae (Phylum Rhodophyta) are considered to be an important source of biologically active metabolites; their use as functional feed ingredients in fish diets can increase disease resistance and animal growth. Furthermore, red macroalgae can be cultured in a sustainable and environmentally friendly manner. We evaluate the potential antiviral activity against the infectious salmon anemia (ISA) virus of Chilean red macroalgae as a sustainable feed additive in the Atlantic salmon (Salmo salar) diet. Lyophilized Chilean red macroalgae concentrates were elaborated and added to a commercial diet. Diets were prepared with 0.1, 1.0, and 10.0 % of Gracilaria chilensis and Pyropia columbina separately, and 0.1 and 1.0 % of a mix of both species in a 1:1 ratio. The diets were fed to S. salar over a period of 2 months. We collected data on production parameters and blood samples. The serum and its constituents were challenged with the ISA virus in the presence of Atlantic salmon kidney cells and tested ex vivo for antiviral capacity using a plaque reduction neutralization assay. Fish fed a diet containing 10 % G. chilensis showed a significantly higher specific growth rate compared with fish fed the control diet. The feed conversion ratio was not significantly affected by treatments. Sera from fish fed the algae diets showed a significant increase in antiviral activity against the ISA virus compared with sera of fish fed the control diet that did not include red macroalgae. Diets including G. chilensis (1.0 and 10 %) exhibited the largest increase in antiviral activity.BioMar Chile S.A. Laboratorio de Genetica y Biotecnologia en Acuicultura, Produccion Animal, Facultad de Ciencias Agronomicas, Universidad de Chil