Fillet yield and fat content in common carp (Cyprinus carpio) produced in three Austrian carp farms with different culture methodologies

The fat content and fillet yield of common carp ( Cyprinus carpio ) from three carp farms were investigated with respect to pond management and overall climatic conditions. The mean fat content of the trimmed fillet varied from 2.7 to 6.9% and differed significantly among the three facilities (P < 0.001). It is suggested that differences in the fillet fat content may be based on the climatic conditions as well as the different management strategies (feeding, stocking biomass). The mean fillet yield was calculated as 34.0–39.0%. No significant correlation between fish weight and fillet yield (ρ = −0.16) was found. Results suggest that producing smaller fish for fillets of serving size may lead to a higher production and conclude with lower production risks and costs.     

Schlank,a member of the ceramide synthase family controls growth and body fat in Drosophila

Ceramide synthases are highly conserved transmembrane proteins involved in the biosynthesis of sphingolipids, which are essential structural components of eukaryotic membranes and can act as second messengers regulating tissue homeostasis. However, the role of these enzymes in development is poorly understood due to the lack of animal models. We identified schlank as a new Drosophila member of the ceramide synthase family. We demonstrate that schlank is involved in the de novo synthesis of a broad range of ceramides, the key metabolites of sphingolipid biosynthesis. Unexpectedly, schlank mutants also show reduction of storage fat, which is deposited as triacylglyerols in the fat body. We found that schlank can positively regulate fatty acid synthesis by promoting the expression of sterol‐responsive element‐binding protein (SREBP) and SREBP‐target genes. It further prevents lipolysis by downregulating the expression of triacylglycerol lipase. Our results identify schlank as a new regulator of the balance between lipogenesis and lipolysis in Drosophila. Furthermore, our studies of schlank and the mammalian Lass2 family member suggest a novel role for ceramide synthases in regulating body fat metabolism.     

SLP‐2 is required for stress‐induced mitochondrial hyperfusion

Mitochondria are dynamic organelles, the morphology of which results from an equilibrium between two opposing processes, fusion and fission. Mitochondrial fusion relies on dynamin‐related GTPases, the mitofusins (MFN1 and 2) in the outer mitochondrial membrane and OPA1 (optic atrophy 1) in the inner mitochondrial membrane. Apart from a role in the maintenance of mitochondrial DNA, little is known about the physiological role of mitochondrial fusion. Here we report that mitochondria hyperfuse and form a highly interconnected network in cells exposed to selective stresses. This process precedes mitochondrial fission when it is triggered by apoptotic stimuli such as UV irradiation or actinomycin D. Stress‐induced mitochondrial hyperfusion (SIMH) is independent of MFN2, BAX/BAK, and prohibitins, but requires L‐OPA1, MFN1, and the mitochondrial inner membrane protein SLP‐2. In the absence of SLP‐2, L‐OPA1 is lost and SIMH is prevented. SIMH is accompanied by increased mitochondrial ATP production and represents a novel adaptive pro‐survival response against stress.     

Porcine spermatozoa inhibit post-breeding cytokine induction in uterine epithelial cells in vivo

Early endometrial cytokine responses after exposure to various inseminate components were investigated for a better understanding of the immunological reactions occurring in the porcine uterus after insemination. Baseline values were established for the mRNA concentrations of GM-CSF, IL-6, IL-10, CXCL8 (interleukin-8), Tumour Necrosis Factor α (TNF-α), TGF-β, cyclooxygenase-2 (COX-2) and arachidonate 5-lipooxygenase (ALOX-5) in periovulatory uterine endometrial tissue using quantitative RT-PCR. Synchronized gilts were inseminated with spermatozoa diluted either in the semen extender Androhep™ or seminal plasma. Uterine infusions of media without spermatozoa were used as controls. Three hours after insemination sows were slaughtered and the expression of the above mentioned cytokines was measured in uterine epithelial cells. Simultaneously, the influx of polymorphonuclear neutrophilic (PMN) granulocytes into the uterus was quantified. Compared to baseline values seminal plasma (SP) and Androhep™ (AH) respectively, if used alone, caused a significant increase in mRNA concentrations of IL-10 (SP: 1.5-fold), TGF-β (AH: 1.5-fold), CXCL8 (AH: 7.1-fold), TNF-α (AH: 1.9-fold) and COX-2 (AH: 7-fold). Surprisingly, in the presence of spermatozoa, none of the tested cytokines revealed mRNA concentrations higher than baseline values. The number of immigrated, intra-luminal PMN correlated only with mRNA concentrations of CXCL8 in presence of Androhep™ (r = 0.51). None of the other cytokines tested seemed to be involved in the regulation of neutrophil recruitment. However, the most interesting result was the sperm-induced down-regulation in the expression of TNF-α, TGF-β, IL-10, CXCL8 and COX-2 to mRNA concentration levels similar to or even below baseline values. In conclusion the results show that CXCL8 contributes significantly to uterine PMN recruitment and indicate a so far underestimated role of porcine spermatozoa in the general regulation of the uterine post-mating inflammatory response.     

Perivascular cells of the supraspinatus tendon express both tendon- and stem cell-related markers

Tendons and ligaments are often affected by mechanical injuries or chronic impairment but other than muscle or bone they possess a low healing capacity. So far, little is known about regeneration of tendons and the role of tendon precursor cells in that process. We hypothesize that perivascular cells of tendon capillaries are progenitors for functional tendon cells and are characterized by expression of marker genes and proteins typical for mesenchymal stem cells and functional tendon cells. Immunohistochemical characterization of biopsies derived from intact human supraspinatus tendons was performed. From these biopsies perivascular cells were isolated, cultured, and characterized using RT-PCR and Western blotting. We have shown for the first time that perivascular cells within tendon tissue express both tendon- and stem/precursor cell-like characteristics. These findings were confirmed by results from in vitro studies focusing on cultured perivascular cells isolated from human supraspinatus tendon biopsies. The results suggest that the perivascular niche may be considered a source for tendon precursor cells. This study provides further information about the molecular nature and localization of tendon precursor cells, which is the basis for developing novel strategies towards tendon healing and facilitated regeneration. H. Tempfer and A. Wagner have contributed equally to this paper.     

O‐glycoside sequence of pentacyclic triterpene saponins from Phytolacca bogotensis using HPLC‐ESI/multi‐stage tandem mass spectrometry

Introduction – The lack of pharmacopoeial methodologies for the quality control of plants used for therapeutic purposes is a huge problem that impacts directly upon public health. In the case of saponins, their great structural complexity, weak glycoside bonds and high polarity hinder their identification by conventional techniques. Objective – To apply high‐performance liquid chromatography–electrospray tandem mass spectrometry (HPLC‐ESI/MSⁿ) to identify the O‐glycoside sequence of saponins from the roots of Phytolacca bogotensis. Methodology – Saponins were isolated by preparative HPLC and characterised by NMR spectroscopic experiments. Collision‐induced dissociation (CID) of isolated saponins was performed producing typical degradation reactions that can be associated with several glycosidic bonds as empirical criteria. A method using solid‐phase extraction (SPE) and HPLC/ESI‐MSⁿ for the characterisation of saponins and identification of novel molecules is described. Results – Three saponins reported for the first time in P. bogotensis were isolated and characterised by NMR spectroscopy. Characteristic cross ring cleavage reactions have been used as empirical criteria for the characterisation of the glycosidic bonds most frequently reported for Phytolacca saponins. One new saponin was proposed on the basis of empirical criteria, and other five saponins were identified for the first time for P. bogotensis using HPLC‐ESI/MSⁿ. Conclusion – Electrospray ionisation in combination with tandem mass spectrometry has been established as a powerful tool for the profiling of saponins from roots of P. bogotensis. CID proved to be a useful tool for the characterisation and identification of known and novel saponins from the plant family Phytolaccaceae and can be used for quality control purposes of crude plant extracts. Copyright © 2009 John Wiley & Sons, Ltd.