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Six populations de carpe commune (Cyprinus carpid) ont été comparées sur la base de quatre critères : morphologie, génétique, rendement de transformation et aspect des filets. Les provenances géographiques des différents lots étudiés correspondent aux principales régions de production piscicole françaises : Dombes, Forez, Brenne, Allier, Lorraine et Poitou-Charentes. Une discrimination géographique des populations est possible mais elle repose sur une approche globale intégrant l'ensemble des paramètres. Les différences semblent essentiellement liées aux conditions environnementales et permettent de distinguer les lots issus des régions où l'élevage est plus intensif et traditionnellement centré sur la carpe (Dombes, Forez, Lorraine) et les lots correspondant à un élevage plus extensif et davantage orienté vers le marché du repeuplement (Allier, Brenne, Poitou-Charentes).

La réponse au stress induit par le transport a été étudiée chez des truites arc-en-ciel immatures d'un poids moyen de 200 g. D'une manière globale, les valeurs de l'hématocrite, de l'osmolarité du plasma sanguin, du Cortisol et de la testostérone sont significativement plus élevées chez les poissons transportés que chez les témoins non transportés, alors que les niveaux de gonadostimuline (GTH1 ) et d'hormone de croissance ne diffèrent pas suivant les lots. L'analyse du comportement en "open field" des individus de chaque lot montre que les poissons transportés s'immobilisent en moyenne après un temps significativement plus long que les témoins. L'étude des performances zootechniques de chaque lot pendant les deux mois suivant l'expérience indique que le lot transporté récupère rapidement.

Abstract Background Inflammation may be involved in the pathogenesis of Alzheimer's disease (AD). There has been little success with anti-inflammatory drugs in AD, while the promise of anti-inflammatory treatment is more evident in experimental models. A new anti-inflammatory strategy requires a better understanding of molecular mechanisms. Among the plethora of signaling pathways activated by β-amyloid (Aβ) peptides, the nuclear factor-kappa B (NF-κB) pathway could be an interesting target. In virus-infected cells, double-stranded RNA-dependent protein kinase (PKR) controls the NF-κB signaling pathway. It is well-known that PKR is activated in AD. This led us to study the effect of a specific inhibitor of PKR on the Aβ42-induced inflammatory response in primary mixed murine co-cultures, allowing interactions between neurons, astrocytes and microglia. Methods Primary mixed murine co-cultures were prepared in three steps: a primary culture of astrocytes and microglia for 14 days, then a primary culture of neurons and astrocytes which were cultured with microglia purified from the first culture. Before exposure to Aβ neurotoxicity (72 h), co-cultures were treated with compound C16, a specific inhibitor of PKR. Levels of tumor necrosis factor-α (TNFα), interleukin (IL)-1β, and IL-6 were assessed by ELISA. Levels of PT451-PKR and activation of IκB, NF-κB and caspase-3 were assessed by western blotting. Apoptosis was also followed using annexin V-FITC immunostaining kit. Subcellular distribution of PT451-PKR was assessed by confocal immunofluorescence and morphological structure of cells by scanning electron microscopy. Data were analysed using one-way ANOVA followed by a Newman-Keuls' post hoc test Results In these co-cultures, PKR inhibition prevented Aβ42-induced activation of IκB and NF-κB, strongly decreased production and release of tumor necrosis factor (TNFα) and interleukin (IL)-1β, and limited apoptosis. Conclusion In spite of the complexity of the innate immune response, PKR inhibition could be an interesting anti-inflammatory strategy in AD.

Gradual heating of myofibril suspensions from brown trout white and red muscles prompts the formation of a gel, according to research designed to characterize the thermal behaviour of myofibril suspensions from white and red muscles of brown trout reared in sea water. This research also considered the impact of protein concentration and heating rate on the gelation process. Significant differences between muscle types were seen at low temperatures, but no differences were identified at high temperature using a heating rate of 1 degree C/min. Trout myofibrils showed a low heat-gelling capacity.

A study was conducted to examine the thermal behavior of myofibril suspensions which were taken from white and red muscles of a brown trout. The protein concentration and heating rate of these muscles and their effects on the gelation process were analyzed. Results revealed that a gel was formed by myofibril suspensions from the white and red muscles of a brown trout after gradual heating. By increasing protein concentration and lowering the heating rate, the rheological characteristics of the gel could be improved.

Trout farming has gained a major role in France as fish demand increases and marine harvests fell short. Biotechnology is a significant factor in the effort to increase productivity of trout farms. A potentially beneficial technology is recombinant trout growth hormone (rtGH). Several scenarios are considered to assess the social benefits of rtGH and those which assume association of the technology with diversification of processed trout products offer the greatest potential. The public acceptance of genetically engineered trout will also be an important factor.

Abstract: The shortage of fish meal and fish oil has led to demonstrate the feasibility of omitting marine ingredients from the diet of rainbow trout. This complete suppression was further studied in the present experiment. Plasma markers indicated that the metabolism was deeply affected in trout fed plant ingredients. The pyrosequencing of reverse transcripts of partial 16S ribosomal RNA revealed the composition of the active bacterial community associated with intestinal mucosa. Most differences appeared between trout fed either a marine diet or a commercial‐like diet with large amounts of plant protein sources and oil. One taxonomic unit of Cetobacterium sp. dominated this microbiota, the overall composition of which was highly variable amongst individuals. This variability in trout fed without marine ingredients was less than in the other dietary groups. At the individual level, the relative prevalence of some bacteria correlated with the level of plasma markers, in particular two distinct taxonomic units of the genus Clostridium, which correlated either with plasma glucose or with several spectral regions containing tyrosine and phenylalanine resonances, detected by 1H‐NMR profiling. Such correlations deserve further investigation for identifying the functional roles of intestinal microbiota. [ABSTRACT FROM AUTHOR]