Plántulas de Populus alba pretratadas con endófitos muestran una mayor tolerancia a Venturia tremulae

Algunos hongos endófitos parecen modular la respuesta de las plantas ante ataques de ciertos patógenos o insectos. En este trabajo se estudió la implicación de hongos endófitos de Populus alba en la tolerancia al patógeno necrotrofo Venturia tremulae, causante de la muerte de ramillos en especies de la sección Populus, siendo P. alba más tolerante que otras especies de la sección. Se evaluó in vitro el efecto de doce cepas de endófitos enfrentándolas al patógeno con el fin de seleccionar aquellas con mayor potencial de biocontrol. Se seleccionaron diez endófitos que fueron inoculados mediante solución esporal de una mezcla de todos ellos, de forma preventiva sobre plántulas de una savia de P. alba. Transcurridos 15 días, se inoculó al patógeno. Aunque en general los síntomas mostrados por las plantas fueron bajos, la mezcla de endófitos redujo la incidencia y severidad de los síntomas causados por el patógeno. Los resultados sugieren que los endófitos de P. alba limitarían los síntomas causados por el patógeno en este hospedante

Causes and consequences of large clonal assemblies in a poplar hybrid zone.

Asexual reproduction is a common and fundamental mode of reproduction in plants. Although persistence in adverse conditions underlies most known cases of clonal dominance, proximal genetic drivers remain unclear, in particular for populations dominated by a few large clones. In this paper, we studied a clonal population of the riparian tree Populus alba in the Douro river basin (northwestern Iberian Peninsula) where it hybridizes with P. tremula, a species that grows in highly contrasted ecological conditions. We used 73 nuclear microsatellites to test whether genomic background (species ancestry) is a relevant cause of clonal success, and to assess the evolutionary consequences of clonal dominance by a few genets. Additional Genotyping-by-Sequencing (GBS) data were produced to estimate the age of the largest clones. We found that a few ancient (over a few thousand years old) and widespread genets dominate the population, both in terms of clone size and number of sexual offspring produced. Interestingly, large clones possessed two genomic regions introgressed from P. tremula, which may have favored their spread under stressful environmental conditions. At the population level, the spread of large genets was accompanied by an overall ancient (>0.1 Myr) but soft decline of effective population size. Despite this decrease, and the high clonality and dominance of sexual reproduction by large clones, the Douro hybrid zone still displays considerable genetic diversity and low inbreeding. This suggests that, even in extreme cases as in the Douro, asexual and sexual dominance of a few large, geographically-extended individuals does not threaten population survival. This article is protected by copyright. All rights reserved

Renal angiomyolipoma in patients with tuberous sclerosis complex: findings from the TuberOus SClerosis registry to increase disease Awareness

BACKGROUND: Renal angiomyolipoma occurs at a high frequency in patients with tuberous sclerosis complex (TSC) and is associated with potentially life-threatening complications. Despite this frequency and severity, there are no large population-based cohort studies. Here we present baseline and follow-up data of the international TuberOus SClerosis registry to increase disease Awareness (TOSCA) with an aim to provide detailed clinical characteristics of renal angiomyolipoma among patients with TSC. METHODS: Patients of any age with a documented clinic visit for TSC within 12 months or who were newly diagnosed with TSC before participation in the registry were eligible. Data specific to renal angiomyolipoma included physical tumour characteristics (multiple, bilateral, lesion size and growing lesions), clinical signs and symptoms, and management. The effects of age, gender and genotype on the prevalence of renal angiomyolipoma were also evaluated. RESULTS: Renal angiomyolipoma was reported in 51.8% of patients at baseline, with higher frequency in female patients (57.8% versus 42.2%). The median age at diagnosis was 12 years. Prevalence of angiomyolipoma was higher in patients with TSC2 compared with TSC1 mutations (59.2% versus 33.3%, P 3 cm in 34.3% of patients. Most patients were asymptomatic (82%). Frequently reported angiomyolipoma-related symptoms included bleeding, pain, elevated blood pressure and impaired renal function. Embolization and mammalian target of rapamycin inhibitors were the two most common treatment modalities. CONCLUSIONS: The TOSCA registry highlights the burden of renal angiomyolipoma in patients with TSC and shows that renal manifestations are initially asymptomatic and are influenced by gender and genotype. Furthermore, the occurrence of significant problems from angiomyolipoma in a minority of younger patients suggests that surveillance should begin in infancy or at initial diagnosis

Species-speciWc defense strategies of vegetative versus reproductive blades of the PaciWc kelps Lessonia nigrescens and Macrocystis integrifolia

Chemical defense is assumed to be costly and therefore algae should allocate defense investments in a way to reduce costs and optimize their overall fitness. Thus, lifetime expectation of particular tissues and their contribution to the fitness of the alga may affect defense allocation. Two brown algae common to the SE Pacific coasts, Lessonia nigrescens Bory and Macrocystis integrifolia Bory, feature important ontogenetic differences in the development of reproductive structures; in L. nigrescens blade tissues pass from a vegetative stage to a reproductive stage, while in M. integrifolia reproductive and vegetative functions are spatially separated on different blades. We hypothesized that vegetative blades of L. nigrescens with important future functions are more (or equally) defended than reproductive blades, whereas in M. integrifolia defense should be mainly allocated to reproductive blades (sporophylls), which are considered to make a higher contribution to fitness. Herein, within-plant variation in susceptibility of reproductive and vegetative tissues to herbivory and in allocation of phlorotannins (phenolics) and N-compounds was compared. The results show that phlorotannin and N-concentrations were higher in reproductive blade tissues for both investigated algae. However, preferences by amphipod grazers (Parhyalella penai) for either tissue type differed between the two algal species. Fresh reproductive tissue of L. nigrescens was more consumed than vegetative tissue, while the reverse was found in M. integrifolia, thus confirming the original hypothesis. This suggests that future fitness function might indeed be a useful predictor of anti-herbivore defense in large, perennial kelps. Results from feeding assays with artificial pellets that were made with air-dried material and extract-treated Ulva powder indicated that defenses in live algae are probably not based on chemicals that can be extracted or remain intact after air-drying and grinding up algal tissues. Instead, anti-herbivore defense against amphipod mesograzers seems to depend on structural traits of living algae

Variation in Patterns of Metal Accumulation in Thallus Parts of Lessonia trabeculata (Laminariales; Phaeophyceae): Implications for Biomonitoring

Seaweeds are well known to concentrate metals from seawater and have been employed as monitors of metal pollution in coastal waters and estuaries. However, research showing that various intrinsic and extrinsic factors can influence metal accumulation, raises doubts about the basis for using seaweeds in biomonitoring programmes. The thallus of brown seaweeds of the order Laminariales (kelps) is morphologically complex but there is limited information about the variation in metal accumulation between the different parts, which might result in erroneous conclusions being drawn if not accounted for in the biomonitoring protocol. To assess patterns of individual metals in the differentiated parts of the thallus (blade, stipe, holdfast), concentrations of a wide range of essential and non-essential metals (Fe, Cr, Cu, Zn, Mn, Pb, Cd, Ni and Al) were measured in the kelp Lessonia trabeculata. Seaweeds were collected from three sampling stations located at 5, 30 and 60 m from an illegal sewage outfall close to Ventanas, Chile and from a pristine location at Faro Curaumilla. For the majority of metals the highest concentrations in bottom sediment and seaweed samples were found at the site closest to the outfall, with concentrations decreasing with distance from the outfall and at control stations; the exception was Cd, concentrations of which were higher at control stations. The patterns of metal concentrations in different thallus parts were metal specific and independent of sampling station. These results and the available literature suggest that biomonitoring of metals using seaweeds must take account of differences in the accumulation of metals in thallus parts of complex seaweedsComment: Research articl

First clinical evidence characterizing safety and efficacy of the new CoCr Biolimus-A9 eluting stent: The Biomatrix Alpha™ registry

Background The biolimus-eluting stent (BES) was the first to elute anti-proliferative drug from a biodegradable polymer. In the randomized LEADERS trial, a stainless steel BES showed non-inferior efficacy compared to a sirolimus-eluting stent and a long-term safety advantage. We report the first clinical efficacy and safety outcomes of a new thin-strut cobalt chromium biolimus-eluting stent (CoCr-BES) from an international multi-centre registry. Methods We studied 400 all-comer patients with coronary disease receiving CoCr-BES at 12 centres, with follow-up at 9 months and 2 years. The primary endpoint was incidence of major adverse cardiac events (MACE) at 9 months comprising cardiac death, myocardial infarction (MI), and clinically indicated target vessel revascularization (ci-TVR). Key protocol elements were the same as the randomized LEADERS trial to enable a historical control for propensity-matched comparison. Results Mean patient age was 65 ± 11 years, 19% had diabetes, and 55% presented with unstable angina or MI. On discharge, 96% of patients were on dual antiplatelet therapy (DAPT) and 69% were on DAPT at 9 months. MACE at 9 months occurred in 3.9% of patients, cardiac death in 0.8%, MI in 1.1% and ci-TVR in 2.7%. One patient (0.25%) experienced definite or probable stent thrombosis (ST). A propensity-adjusted comparison showed similar clinical outcomes to the BES arm in the LEADERS trial for the primary endpoint MACE. Conclusions The new CoCr-BES showed low rates of MACE, MI, ci-TVR and ST at 9 months, similar to the BES arm in LEADERS

A multi-scale analysis of bull sperm methylome revealed both species peculiarities and conserved tissue-specific

peer-reviewedBackground: Spermatozoa have a remarkable epigenome in line with their degree of specialization, their unique nature and different requirements for successful fertilization. Accordingly, perturbations in the establishment of DNA methylation patterns during male germ cell differentiation have been associated with infertility in several species.Background: Spermatozoa have a remarkable epigenResults: The quantification of DNA methylation at CCGG sites using luminometric methylation assay (LUMA) highlighted the undermethylation of bull sperm compared to the sperm of rams, stallions, mice, goats and men. Total blood cells displayed a similarly high level of methylation in bulls and rams, suggesting that undermethylation of the bovine genome was specific to sperm. Annotation of CCGG sites in different species revealed no striking bias in the distribution of genome features targeted by LUMA that could explain undermethylation of bull sperm. To map DNA methylation at a genome-wide scale, bull sperm was compared with bovine liver, fibroblasts and monocytes using reduced representation bisulfite sequencing (RRBS) and immunoprecipitation of methylated DNA followed by microarray hybridization (MeDIP-chip). These two methods exhibited differences in terms of genome coverage, and consistently, two independent sets of sequences differentially methylated in sperm and somatic cells were identified for RRBS and MeDIP-chip. Remarkably, in the two sets most of the differentially methylated sequences were hypomethylated in sperm. In agreement with previous studies in other species, the sequences that were specifically hypomethylated in bull sperm targeted processes relevant to the germline differentiation program (piRNA metabolism, meiosis, spermatogenesis) and sperm functions (cell adhesion, fertilization), as well as satellites and rDNA repeats. Conclusions: These results highlight the undermethylation of bull spermatozoa when compared with both bovine somatic cells and the sperm of other mammals, and raise questions regarding the dynamics of DNA methylation in bovine male germline. Whether sperm undermethylation has potential interactions with structural variation in the cattle genome may deserve further attention. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bull spermatozoa is still scarce. The purpose of this study was therefore to characterize the bull sperm methylome relative to both bovine somatic cells and the sperm of other mammals through a multiscale analysis