A member of a new plant gene family encoding a meprin and TRAF homology (MATH) domain-containing protein is involved in restriction of long distance movement of plant viruses

Restriction of long distance movement of several potyviruses in Arabidopsis thaliana is controlled by at least three dominant restricted TEV movement (RTM) genes, named RTM1, RTM2 and RTM3 and acts as a non-conventional resistance. RTM1 encodes a protein belonging to the jacalin family and RTM2 encodes a protein which has similarities to small heat shock proteins. The recent cloning of RTM3 which encodes a protein belonging to an unknown protein family of 29 members that has a meprin and TRAF homology (MATH) domain in its N-terminal region and a coiled-coil (CC) domain at its C-terminal end is an important breakthrough for a better understanding of this resistance process. Not only the third gene involved in this resistance has been identified and has allowed revealing a new gene family in plant but the discovery that the RTM3 protein interacts directly with RTM1 strongly suggests that the RTM proteins form a multimeric complex. However, these data also highlight striking similarities of the RTM resistance with the well known R-gene mediated resistance.Key words: plant virus, potyvirus, resistance, long distance movement, RTM genes, Arabidopsis thaliana     

Parental mortality rates in a western country after the death of a child: assessment of the role of the child's sex

Background: Loss of a child has been associated with elevated mortality rates in parents. Studies that focus on the influence of the child's sex on parental mortality are sparse.Objective: The main objective of the present study was to reevaluate the combined impact of the parents' and child's sex within a larger sample and focus on adverse health effects as an objective measure of possible long-term effects of maladaptive grief reactions.Methods: For the time period between 1980 and 1996, all children in Denmark who died before 18 years of age were identified. Parents who had lost a child were identified as the bereaved (exposed) group. Mortality rates of parents within the same-sex parent-child dyad were compared with mortality rates of parents within the opposite-sex parent-child dyad. Separate analyses were performed for bereaved fathers and for bereaved mothers, and additional analyses were conducted to examine the sole effect of the child's sex, irrespective of parental gender. A Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) with 95% CIs.Results: The study population consisted of 21,062 parents (mean age at entry, 32 years; 11,221 mothers, 9841 fathers). Bereaved parents who had lost a child of the same sex had similar overall mortality as bereaved parents who had lost a child of the opposite sex (HR = 1.02; 95% CI, 0.85–1.22). Similar findings were observed for mortality due to natural death (HR = 0.96; 95% CI, 0.78–1.18) or mortality due to unnatural death (HR = 1.22; 95% CI, 0.84–1.77). Bereaved fathers who had lost a son had similar mortality as those bereaved by the death of a daughter (HR = 1.10; 95% CI, 0.86–1.40). Bereaved mothers who had lost a daughter had similar mortality as those bereaved by the death of a son (HR = 0.93; 95% CI, 0.70–1.22). Bereaved parents who had lost a son had mortality rates similar to those who had lost a daughter (HR = 1.09; 95% CI, 0.91–1.31). The interactions between grouping variable and sex of parents were not significant, indicating that the differential effect of losing a child based on sex of the child was not greater for fathers than for mothers.Conclusions: The results of this study revealed no significant effect of sex of the deceased child on mortality in these bereaved parents. The results might differ if this study was replicated in a population with a different grief culture and, more importantly, different gender schemas.     

Moandaensine,a dimeric indole alkaloid from Strychnos moandaensis (Loganiaceae)

The chemical investigation of the liana Strychnos moandaensis De Wild. led to the isolation of moandaensine, a novel dimeric indole alkaloid. The structure was elucidated by a thorough analysis of the spectroscopic data and by molecular modeling. Moandaensine, or methyl (2S)-2-[(2R,3E,12bS)-3-ethylidene-2,4,6,7,12,12b-hexahydro-1H-indolo[2,3-a]quinolizin-2-yl]-3-[(2S,3R)-3-ethyl-2-[(1R)-1-(hydroxymethyl)-2-methoxy-2-oxo-ethyl]-1,2,3,4-tetrahydroindolo[2,3-a]quinolizin-5-ium-7-yl]propanoate, contains a rare anhydronium base subunit. It presents a moderate antiplasmodial activity with IC₅₀ values of 11.2 and 9.2 μM against, respectively, the chloroquine sensitive FCA 20 GHA and chloroquine resistant W2 strains of Plasmodium falciparum.     

Erythropoietin improves the survival of fat tissue after its transplantation in nude mice

Background

Autologous transplanted fat has a high resorption rate, providing a clinical challenge for the means to reduce it. Erythropoietin (EPO) has non-hematopoietic targets, and we hypothesized that EPO may improve long-term fat graft survival because it has both pro-angiogenic and anti-apoptotic properties. We aimed to determine the effect of EPO on the survival of human fat tissue after its transplantation in nude mice.

Methodology/Principal Findings

Human fat tissue was injected subcutaneously into immunologically-compromised nude mice, and the grafts were then treated with either 20 IU or 100 IU EPO. At the end of the 15-week study period, the extent of angiogenesis, apoptosis, and histology were assessed in the fat grafts. The results were compared to vascular endothelial growth factor (VEGF)-treated and phosphate-buffered saline (PBS)-treated fat grafts. The weight and volume of the EPO-treated grafts were higher than those of the PBS-treated grafts, whose weights and volumes were not different from those of the VEGF-treated grafts. EPO treatment also increased the expression of angiogenic factors and microvascular density, and reduced inflammation and apoptosis in a dose-dependent manner in the fat grafts.

Conclusions/Significance

Our data suggest that stimulation of angiogenesis by a cluster of angiogenic factors and decreased fat cell apoptosis account for potential mechanisms that underlie the improved long-term survival of fat transplants following EPO treatment.     

New alkamide and ent-kaurane diterpenoid derivatives from Senecio erechtitoides (Asteraceae)

Fractionation of a MeOH/CH₂Cl₂ (1/1) extract of the aerial parts of Senecio erechtitoides led to the isolation of six compounds including the hitherto unknown N-phenethylamide derivative named N-(p-hydroxyphenethyl)pentacosanamide (1), and a kauranoid derivative named derivative named ent-7-oxo-16α,17-dihydroxykauran-19-oic acid (2), as well as four known compounds, ent-Kaur-16-en-19-oic acid (3), ent-7β-hydroxykaur-16-en-19-oic acid (4), ent-7-oxokaur-16-en-19-oic acid (5), steppogenin 4′-O-β-d-glucoside (6). Their structures and relative configurations were elucidated on the basis of spectroscopic methods, chemical reactions, and comparison with previously known analogs. All isolates were evaluated for their antimicrobial activity and only diterpenoids were found to possess a potent inhibitor effect against the range of microorganism.     

Metarhizium anisopliae host-pathogen interaction: differential immunoproteomics reveals proteins involved in the infection process of arthropods

Metarhizium anisopliae is an entomopathogenic fungus well characterized for the biocontrol of a wide range of plagues. Its pathogenicity depends on the secretion of hydrolytic enzymes that degrade the host cuticle. To identify proteins involved in the infection process and in host specify, immunoproteomic analysis was performed using antiserum produced against crude extract of M. anisopliae cultured in the presence of Rhipicephalus (Boophilus) microplus and Dysdercus peruvianus cuticles. Spots detected using antisera produced against M. anisopliae cultured in cuticles and spore surface proteins, but not with antiserum against M. anisopliae cultured in glucose, were identified so as to give insights about the infection process. An MS/MS allowed the identification of proteases, like elastase, trypsin, chymotrypsin, carboxypeptidase and subtilisin (Pr1A, Pr1I and PR1J), chitinases, DNase I and proline-rich protein. Chymotrypsin and Pr1I were inferred as host specific, being recognized in D. peruvianus infection only. This research represents an important contribution to the understanding the adaptation mechanisms of M. anisopliae to different hosts.     

Lipid particle composition of the yeast Yarrowia lipolytica depends on the carbon source

Lipid particles (LP) of all types of cells are a depot of neutral lipids. The present investigation deals with the isolation of LP from the yeast Yarrowia lipolytica and the characterization of their lipid and protein composition. Properties of LP varied depending on the carbon source. LP from glucose-grown cells revealed a mean diameter of 650 nm with a hydrophobic core mainly formed of triacylglycerols (TAG) and a minor amount of steryl esters (SE). Oleic acid was the major fatty acid species esterified in LP. When cells were grown on oleic acid, LP size increased 3.8-fold, the particles exhibited a significantly lower ratio of TAG to SE, and the relative amount of oleic acid in LP lipids increased compared to cells grown on glucose. Analysis of LP proteins revealed an increasing number of polypeptides when cells were shifted from glucose- to oleic acid-containing medium. Twenty-one major LP proteins were identified under both growth conditions, and additional nine polypeptides were specific for growth on oleic acid. Identification of these proteins by MS and comparison of the deduced ORFs to those from Saccharomyces cerevisiae revealed that most proteins of Y. lipolytica LP are involved in lipid metabolism. LP proteins specific for growth on oleic acid are also enzymes involved in lipid metabolism, but some of them are also components of the intracellular traffic machinery. Thus, proteom analysis of LP proteins suggests involvement of this compartment in different cell biological processes.     

Effects of management regime and plant species on the enzyme activity and genetic structure of N-fixing, denitrifying and nitrifying bacterial communities in grassland soils

Management by combined grazing and mowing events is commonly used in grasslands, which influences the activity and composition of soil bacterial communities. Whether observed effects are mediated by management-induced disturbances, or indirectly by changes in the identity of major plant species, is still unknown. To address this issue, we quantified substrate-induced respiration (SIR), and the nitrification, denitrification and free-living N(2)-fixation enzyme activities below grass tufts of three major plant species (Holcus lanatus, Arrhenatherum elatius and Dactylis glomerata) in extensively or intensively managed grasslands. The genetic structures of eubacterial, ammonia oxidizing, nitrate reducing, and free-living N(2)-fixing communities were also characterized by ribosomal intergenic spacer analysis, and denaturing gradient gel electrophoresis (DGGE) or restriction fragment length polymorphism (RFLP) targeting group-specific genes. SIR was not influenced by management and plant species, whereas denitrification enzyme activity was influenced only by plant species, and management-plant species interactions were observed for fixation and nitrification enzyme activities. Changes in nitrification enzyme activity were likely largely explained by the observed changes in ammonium concentration, whereas N availability was not a major factor explaining changes in denitrification and fixation enzyme activities. The structures of eubacterial and free-living N(2)-fixing communities were essentially controlled by management, whereas the diversity of nitrate reducers and ammonia oxidizers depended on both management and plant species. For each functional group, changes in enzyme activity were not correlated or were weakly correlated to overall changes in genetic structure, but around 60% of activity variance was correlated to changes in five RFLP or DGGE bands. Although our conclusions should be tested for other ecosystems and seasons, these results show that predicting microbial changes induced by management in grasslands requires consideration of management-plant species interactions.