Intraspecific phenotypic differences in fish affect ecosystem processes as much as bottom–up factors

Evolution of life history traits can occur rapidly and has the potential to influence ecological processes, which can also be shaped by abiotic and biotic factors. Few studies have shown that life history phenotype can affect ecological processes as much as commonly studied biotic ecological variables, but currently we do not know how the ecological effects of life history phenotype compare in size to the effects of abiotic factors, or whether the ecological effects of phenotypes are sensitive to variability in abiotic conditions. Using a factorial mesocosm experiment we compared the ecosystem effects of guppy Poecilia reticulata life history phenotypes in two light treatments representing a four‐fold difference in light levels, which was comparable to upstream downstream differences in light availability in Trinidadian streams. Light and phenotype had significant effects on similar aspects of ecosystem function. Whereas light had a stronger effect on ecosystem structure (algal and invertebrate stocks) than phenotype, phenotype and light had nearly equal effects on many ecosystem processes (nutrient recycling, nutrient fluxes, ecosystem metabolism and leaf litter decomposition). Light had a stronger effect on most guppy life history traits and guppy fitness than differences between phenotypes. The effect of light on these traits was consistent with higher availability of food resources in the high light treatments. Interactions between light and phenotype were weak for the majority of response variables suggesting that abiotic variability did not alter the mechanisms by which phenotypes affect ecosystem function. We conclude that subtle phenotypic differences in consumers can affect ecosystem processes as much as meaningful variability in abiotic factors which until recently were thought to be the primary drivers of ecosystem function in nature. However, despite its effects on traits and the ecosystem, light did not alter the effect of guppy phenotype on ecosystem function.     

Protective role of fish oil (Maxepa) on early events of rat mammary carcinogenesis by modulation of DNA-protein crosslinks,cell proliferation and p53 expression

Background  

Fish oil is known to protect from many types of cancers of the colon, liver, breast, prostate and lung [1–3]. The objective of the present study was to evaluate the role of fish oil [Maxepa, supplemented at a dose of 0.5 ml is equivalent to 90 mg eicosapentaenoic acid (EPA) and 60 mg docosahexaenoic acid (DHA)] on cell proliferation, expression of p53 tumor suppressor protein and DNA protein crosslinks (DPCs) in a defined model of chemical rat mammary carcinogenesis. Mammary carcinogenesis was initiated by a single, intravenous (i.v.) tail vein injection of 7,12 dimethylbenz(α)anthracene (DMBA) at a dose of 5 mg DMBA/2 ml corn oil/kg body weight in female Sprague-Dawley rats at 7 weeks of age. Fish oil supplementation was started daily, 2 weeks prior to DMBA injection and continued for 24 (31 weeks of animal age) weeks and 35 (42 weeks of animal age) weeks of post DMBA injection, for histopathological and immunohistochemical and for morphological studies, respectively.     

Mass spectrometry analysis of the human endosulfatase Hsulf-2

The human 6-O-endosulfatases HSulf-1 and -2 catalyze the region-selective hydrolysis of the 6-O-sulfate group of the glucosamine residues within sulfated domains of heparan sulfate, thereby ensuring a unique and original post-biosynthetic modification of the cell surface proteoglycans. While numerous studies point out the role of HSulf-2 in crucial physiological processes as well as in pathological conditions particularly in cancer, its structural organization in two chains and its functional properties remain poorly understood. In this study, we report the first characterization by mass spectrometry (MS) of HSulf-2. An average molecular weight of 133,115 Da was determined for the whole enzyme by MALDI-TOF MS, i.e. higher than the naked amino acid backbone (98,170 Da), highlighting a significant contribution of post-translational modifications. The HSulf-2 protein sequence was determined by Nano-LC-MS/MS, leading to 63% coverage and indicating at least four N-glycosylation sites at Asn 108, 147, 174 and 217. These results provide a platform for further structural investigations of the HSulf enzymes, aiming at deciphering the role of each chain in the substrate binding and specificities and in the catalytic activities.     

Endocardially Derived Macrophages Are Essential for Valvular Remodeling

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Titanium-Coated Dual-Core D-Shaped SPR-Based PCF for Hemoglobin Sensing

Plasmonics - Two new dual-core D-shaped SPR (surface plasmon resonance) PCFs (photonic crystal fibers) (DCD-S-SPR PCF) with a splitting barrier between the twin cores are proposed for the detection...     

Quorum sensing involvement in response surface methodology for optimisation of sclerotiorin production by Penicillium sclerotiorum in shaken flasks and bioreactors

Sclerotiorin, an azaphilone produced by some filamentous fungi including Penicillium sclerotiorum, is a pigment with variety of biological activities including lipoxygenase inhibition, reduction of cholesterol levels, and anti-cancer properties. Sclerotiorin has potential use in pharmaceutical as well as food industries. In this context, the purpose of this study was to provide a simple and robust procedure for optimised production of sclerotiorin by P. sclerotiorum using a central composite design developed through response surface methodology (RSM) and to identify the molecule(s) involved in the signalling mechanism in P. sclerotiorum. The optimisation of sclerotiorin production was carried out using RSM in shaken flasks and the obtained results were then replicated using a 2-L stirred tank bioreactor. Penicillium sclerotiorum ethyl acetate culture extract was analysed using thin layer chromatography (TLC) and potential signalling molecules were identified using Gas chromatography-mass spectrometry (GC-MS). The experimental studies suggested an increase in the sclerotiorin production by 2.1-fold and 2.2-fold in shaken flasks and stirred tank bioreactors respectively. Further analysis of P. sclerotiorum ethyl acetate culture extract reported the presence of ricinoleic acid, an oxylipin, belonging to a family of signalling molecules tentatively involved in the enhancement of sclerotiorin production. This paper has highlighted the positive effect of the optimal supplementation of P. sclerotiorum culture extracts for enhanced production of sclerotiorin. It has also examined potential molecules involved in the signalling mechanism in P. sclerotiorum culture extract for the overproduction of sclerotiorin.     

Discovery of novel multi-target indole-based derivatives as potent and selective inhibitors of chikungunya virus replication

We recently identified indole derivatives (IIIe and IIIf) with anti-chikungunya virus (CHIKV) activities at lower micro molar concentrations and a selective index of inhibition higher than the lead compound Arbidol. Here we highlight new structural information for the optimization of the previously identified lead compounds that contain the indole chemical core. Based on the structural data, a series of indole derivatives was synthesized and tested for their antiviral activity against chikungunya virus in Vero cell culture by a CPE reduction assay.Systematic optimization of the lead compounds resulted in tert-butyl-5-hydroxy-1-methyl-2-(2-trifluoromethysulfynyl)methyl)-indole-3-carboxylate derivative IIc with a 10-fold improved anti-CHIKV inhibitory activity (EC₅₀ = 6.5 ± 1 μM) as compared to Arbidol demonstrating a potent, selective and specific inhibition of CHIKV replication with only a moderate cell protective effect against other related alphaviruses. The reported computational insights, together with the accessible synthetic procedure, pave the road towards the design of novel synthetic derivatives with enhanced anti-viral activities.