Epiparasitic plants specialized on arbuscular mycorrhizal fungi

Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature

Community-acquired pneumonia in the United Kingdom:a call to action

Abstract Pneumococcal disease has a high burden in adults in the United Kingdom (UK); however, the total burden is underestimated, principally because most cases of community-acquired pneumonia (CAP) are non-invasive. Research into pneumonia receives poor funding relative to its disease burden (global mortality, disability-adjusted life years, and years lived with disability), ranking just 20 out of 25 for investment in infectious diseases in the UK. The current accuracy of data for establishing incidence rates is questionable, and it is a reflection of the paucity of research that much of the background information available derives from nearly 30 years ago. Given the relationship between CAP and mortality (pneumonia accounts for 29,000 deaths per annum in the UK, and 5–15% of patients hospitalised with CAP die within 30 days of admission), and the increasing threat of antimicrobial resistance associated with inappropriate antibiotic prescribing, such neglect of a highly prevalent problem is concerning. In this Call to Action, we explore the poorly understood burden of CAP in the UK, discuss the importance of an accurate diagnosis and appropriate treatment, and suggest how national collaboration could improve the management of an often life-threatening, yet potentially preventable disease

Hydrophobins—Unique Fungal Proteins

International audienc

Repercussion of megakaryocyte-specific Gata1 Loss on megakaryopoiesis and the hematopoietic precursor compartment

During hematopoiesis, transcriptional programs are essential for the commitment and differentiation of progenitors into the different blood lineages. GATA1 is a transcription factor expressed in several hematopoietic lineages and essential for proper erythropoiesis and megakaryopoiesis. Megakaryocyte-specific genes, such as GP1BA, are known to be directly regulated by GATA1. Mutations in GATA1 can lead to dyserythropoietic anemia and pseudo gray-platelet syndrome. Selective loss of Gata1 expression in adult mice results in macrothrombocytopenia with platelet dysfunction, characterized by an excess of immature megakaryocytes. To specifically analyze the impact of Gata1 loss in mature committed megakaryocytes, we generated Gata1-Lox|Pf4-Cre mice (Gata1cKOMK). Consistent with previous findings, Gata1cKOMK mice are macrothrombocytopenic with platelet dysfunction. Supporting this notion we demonstrate that Gata1 regulates directly the transcription of Syk, a tyrosine kinase that functions downstream of Clec2 and GPVI receptors in megakaryocytes and platelets. Furthermore, we show that Gata1cKOMK mice display an additional aberrant megakaryocyte differentiation stage. Interestingly, these mice present a misbalance of the multipotent progenitor compartment and the erythroid lineage, which translates into compensatory stress erythropoiesis and splenomegaly. Despite the severe thrombocytopenia, Gata1cKOMK mice display a mild reduction of TPO plasma levels, and Gata1cK-OMK megakaryocytes show a mild increase in Pf4 mRNA levels; such a misbalance might be behind the general hematopoietic defects observed, affecting locally normal TPO and Pf4 levels at hematopoietic stem cell niches. © 2016 Meinders et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Molecular analysis of enrichment cultures of ammonia oxidizers from the Salar de Huasco, a high altitude saline wetland in northern Chile

We analyzed enrichment cultures of ammonia-oxidizing bacteria (AOB) collected from different areas of Salar de Huasco, a high altitude, saline, pH-neutral water body in the Chilean Altiplano. Samples were inoculated into mineral media with 10 mM NH4+ at five different salt concentrations (10, 200, 400, 800 and 1,400 mM NaCl). Low diversity (up to three phylotypes per enrichment) of beta-AOB was detected using 16S rDNA and amoA clone libraries. Growth of beta-AOB was only recorded in a few enrichment cultures and varied according to site or media salinity. In total, five 16S rDNA and amoA phylotypes were found which were related to Nitrosomonas europaea/Nitrosococcus mobilis, N. marina and N. communis clusters. Phylotype 1-16S was 97% similar with N. halophila, previously isolated from Mongolian soda lakes, and phylotypes from amoA sequences were similar with yet uncultured beta-AOB from different biofilms. Sequences related to N. halophila were frequently found at all salinities. Neither gamma-AOB nor ammonia-oxidizing Archaea were recorded in these enrichment cultures

Treatment of osteochondral lesions of the talus: a systematic review

The aim of this study was to summarize all eligible studies to compare the effectiveness of treatment strategies for osteochondral defects (OCD) of the talus. Electronic databases from January 1966 to December 2006 were systematically screened. The proportion of the patient population treated successfully was noted, and percentages were calculated. For each treatment strategy, study size weighted success rates were calculated. Fifty-two studies described the results of 65 treatment groups of treatment strategies for OCD of the talus. One randomized clinical trial was identified. Seven studies described the results of non-operative treatment, 4 of excision, 13 of excision and curettage, 18 of excision, curettage and bone marrow stimulation (BMS), 4 of an autogenous bone graft, 2 of transmalleolar drilling (TMD), 9 of osteochondral transplantation (OATS), 4 of autologous chondrocyte implantation (ACI), 3 of retrograde drilling and 1 of fixation. OATS, BMS and ACI scored success rates of 87, 85 and 76%, respectively. Retrograde drilling and fixation scored 88 and 89%, respectively. Together with the newer techniques OATS and ACI, BMS was identified as an effective treatment strategy for OCD of the talus. Because of the relatively high cost of ACI and the knee morbidity seen in OATS, we conclude that BMS is the treatment of choice for primary osteochondral talar lesions. However, due to great diversity in the articles and variability in treatment results, no definitive conclusions can be drawn. Further sufficiently powered, randomized clinical trials with uniform methodology and validated outcome measures should be initiated to compare the outcome of surgical strategies for OCD of the talus

Altered T Cell Memory and Effector Cell Development in Chronic Lymphatic Filarial Infection That Is Independent of Persistent Parasite Antigen

Chronic lymphatic filarial (LF) infection is associated with suppression of parasite-specific T cell responses that persist even following elimination of infection. While several mechanisms have been implicated in mediating this T cell specific downregulation, a role for alterations in the homeostasis of T effector and memory cell populations has not been explored. Using multiparameter flow cytometry, we investigated the role of persistent filarial infection on the maintenance of T cell memory in patients from the filarial-endemic Cook Islands. Compared to filarial-uninfected endemic normals (EN), microfilaria (mf) positive infected patients (Inf) had a reduced CD4 central memory (TCM) compartment. In addition, Inf patients tended to have more effector memory cells (TEM) and fewer effector cells (TEFF) than did ENs giving significantly smaller TEFF ∶ TEM ratios. These contracted TCM and TEFF populations were still evident in patients previously mf+ who had cleared their infection (CLInf). Moreover, the density of IL-7Rα, necessary for T memory cell maintenance (but decreased in T effector cells), was significantly higher on memory cells of Inf and CLInf patients, although there was no evidence for decreased IL-7 or increased soluble IL7-Rα, both possible mechanisms for signaling defects in memory cells. However, effector cells that were present in Inf and CLInf patients had lower percentages of HLA-DR suggesting impaired function. These changes in T cell populations appear to reflect chronicity of infection, as filarial-infected children, despite the presence of active infection, did not show alterations in the frequencies of these T cell phenotypes. These data indicate that filarial-infected patients have contracted TCM compartments and a defect in effector cell development, defects that persist even following clearance of infection. The fact that these global changes in memory and effector cell compartments do not yet occur in infected children makes early treatment of LF even more crucial