Artificial selection for timing of dispersal in predatory mites yields lines that differ in prey exploitation strategies

Dispersal is the main determinant of the dynamics and persistence of predator–prey metapopulations. When defining dispersal as a predator exploitation strategy, theory predicts the existence of a continuum of strategies: from some dispersal throughout the predator–prey interaction (the Milker strategy) to dispersal only after the prey had been exterminated (the Killer strategy). These dispersal strategies relate to differences in prey exploitation at the population level, with more dispersal leading to longer predator–prey interaction times and higher cumulative numbers of dispersing predators. In the predatory mite Phytoseiulus persimilis, empirical studies have shown genetic variation for prey exploitation as well as for the timing of aerial dispersal in the presence of prey. Here, we test whether artificial selection for lines that differ in timing of dispersal also results in these lines differing in prey exploitation. Six rounds of selection for early or late dispersal resulted in predator lines displaying earlier or later dispersal. Moreover, it resulted—at the population level—in predicted differences in the local predator–prey interaction time and in the cumulative numbers of dispersers in a population dynamics experiment. We pose that timing of dispersal is a heritable trait that can be selected in P. persimilis, which results in lines that show quantitative differences in local predator–prey dynamics. This opens ways to experimentally investigate the evolution of alternative prey exploitation strategies and to select for predator strains with prey exploitation strategies resulting in better biological control

Mental Health screening in cystic fibrosis centres across Europe

Objectives: The Cystic Fibrosis (CF) International Mental Health Guidelines Committee published consensus statements for screening and treating depression and anxiety in individuals with CF and their caregivers. This work aimed to evaluate the dissemination and implementation of the guidelines in Europe two years following their publication. Methods: A 28-item survey was developed by the multidisciplinary ECFS Mental Health Working Group and emailed to approximately 300 CF centres across Europe. The survey evaluated (a) who should be responsible for mental health (MH) care, (b) the current awareness and agreement of the guidelines, (c) the provision of recommended MH screening and follow-up care, and (d) successes, barriers and required resources/training needs. Results: Responses were received from 187 centres (28 countries represented). There was consensus that a psychologist should be responsible for MH care, although members of the multidisciplinary team (MDT) believed they should also share this responsibility. Sixty-two percent of respondents were aware of the guidelines; 82% percent fully, and 12% partially, agreed with them. Fifty percent (94 centres) had implemented screening. In the past year approximately 6000 patients and 2000 caregivers had been screened, with 80% of respondents using the recommended screening tools. Respondents reported 551 referrals for moderate/severe psychopathology and 84 urgent suicide ideation referrals. Conclusions: The challenges of different healthcare systems and language barriers are being overcome with a greater awareness of the importance of mental health among the MDT. MH screening is feasible and gaining momentum in both Western and Eastern Europe

European Consortium of Microbial Resources Centres (EMbaRC): Secure the future of microbial resources at laboratory scale

[Excerpt] EMbaRC is an EU project which aims to improve, coordinate and validate microbial resource centre (MRC) delivery to the European and International researchers. To ensure harmonisation of the quality of MRCs, EMbaRC plans to take the current OECD best practice guidelines and emerging national standards for Biological Resource Centres (BRCs) to the international level. Outreach and training activities will ensure that not only the consortium but that all European collections operate to the standards required to deliver products and services of consistent quality thus meeting customer needs. A one-stop access to the collections of EMbaRC and the wider European BRC community via a searchable web portal building on the outcomes of the CABRI and EBRCN is being developed. (...

Inter-laboratory evaluation, development and validation of fungal preservation regimes used in different European biological resources centres (BRCs)

Successful preservation of fungi relies on the application of optimised preservation protocols that do not compromise the genomic integrity of the organism. Most major European BRCs use lyophilisation and cryopreservation as the methods of choice. Although based on generic principals, protocols can vary between institutions and do not always result in successful recovery. In order to evaluate the efficacy of the methods, a range of fungal strains were circulated around partner collections in the EMbaRC project and the organisms preserved using the standard methods used in each collection. The effectiveness of preservation was assessed using a series of techniques including DNA fingerprinting and sequencing, analysis of culture characteristics, viability assessments and the use of MALDI-TOF. The results showed that when viable cultures were obtained after preservation, they appeared to retain their genomic integrity, but there was evidence of delayed growth and attenuation in some cultures. Not all fungi were successfully preserved by all methods. It was found that a cryopreservation protocol used by the MUCL collection in Belgium, that limited manipulation of the fungus before preservation, was particularly effective in preserving some of the more delicate fungi and this method is being evaluated by the project partners. A further investigation was undertaken to assess the integrity of four specific strains of fungi deposited in different collections. They were compared using culture analysis, sequence analysis, DNA fingerprinting and MALDI-TOF. It was found that some limited variation was observed at the phenotypic level from the analysis of culture characteristics, but this could be expected, especially in organisms such as Aspergillus which can be prone to strain drift. More importantly, molecular integrity remained consistent with no significant differences observed between lines of the same strain. Therefore, despite the strains having been maintained by different methods over the intervening years from their initial deposit, the collections had maintained them in a stable manner. This is indicative of the benefits of applying proven regimes, resulting in high quality operations

Periconceptional Maternal Folic Acid Use of 400 µg per Day Is Related to Increased Methylation of the IGF2 Gene in the Very Young Child

Background: Countries worldwide recommend women planning pregnancy to use daily 400 mg of synthetic folic acid in the periconceptional period to prevent birth defects in children. The underlying mechanisms of this preventive effect are not clear, however, epigenetic modulation of growth processes by folic acid is hypothesized. Here, we investigated whether periconceptional maternal folic acid use and markers of global DNA methylation potential (S-adenosylmethionine and S-adenosylhomocysteine blood levels) in mothers and children affect methylation of the insulin-like growth factor 2 gene differentially methylation region (IGF2 DMR) in the child. Moreover, we tested whether the methylation of the IGF2 DMR was independently associated with birth weight. Methodology/Principal Findings: IGF2 DMR methylation in 120 children aged 17 months (SD 0.3) of whom 86 mothers had used and 34 had not used folic acid periconceptionally were studied. Methylation was measured of 5 CpG dinucleotides covering the DMR using a mass spectrometry-based method. Children of mother who used folic acid had a 4.5% higher methylation of the IGF2 DMR than children who were not exposed to folic acid (49.5% vs. 47.4%; p = 0.014). IGF2 DMR methylation of the children also was associated with the S-adenosylmethionine blood level of the mother but not of the child (+1.7% methylation per SD S-adenosylmethionine; p = 0.037). Finally, we observed an inverse independent association between IGF2 DMR methylation and birth weight (-1.7% methylation per SD birthweight; p = 0.034). Conclusions: Periconceptional folic acid use is associated with epigenetic changes in IGF2 in the child that may affect intrauterine programming of growth and development with consequences for health and disease throughout life. These results indicate plasticity of IGF2 methylation by periconceptional folic acid use

Calcium Triggered Lα-H2 Phase Transition Monitored by Combined Rapid Mixing and Time-Resolved Synchrotron SAXS

BACKGROUND: Awad et al. reported on the Ca(2+)-induced transitions of dioleoyl-phosphatidylglycerol (DOPG)/monoolein (MO) vesicles to bicontinuous cubic phases at equilibrium conditions. In the present study, the combination of rapid mixing and time-resolved synchrotron small-angle X-ray scattering (SAXS) was applied for the in-situ investigations of fast structural transitions of diluted DOPG/MO vesicles into well-ordered nanostructures by the addition of low concentrated Ca(2+) solutions. METHODOLOGY/PRINCIPAL FINDINGS: Under static conditions and the in absence of the divalent cations, the DOPG/MO system forms large vesicles composed of weakly correlated bilayers with a d-spacing of approximately 140 A (L(alpha)-phase). The utilization of a stopped-flow apparatus allowed mixing these DOPG/MO vesicles with a solution of Ca(2+) ions within 10 milliseconds (ms). In such a way the dynamics of negatively charged PG to divalent cation interactions, and the kinetics of the induced structural transitions were studied. Ca(2+) ions have a very strong impact on the lipidic nanostructures. Intriguingly, already at low salt concentrations (DOPG/Ca(2+)>2), Ca(2+) ions trigger the transformation from bilayers to monolayer nanotubes (inverted hexagonal phase, H(2)). Our results reveal that a binding ratio of 1 Ca(2+) per 8 DOPG is sufficient for the formation of the H(2) phase. At 50 degrees C a direct transition from the vesicles to the H(2) phase was observed, whereas at ambient temperature (20 degrees C) a short lived intermediate phase (possibly the cubic Pn3m phase) coexisting with the H(2) phase was detected. CONCLUSIONS/SIGNIFICANCE: The strong binding of the divalent cations to the negatively charged DOPG molecules enhances the negative spontaneous curvature of the monolayers and causes a rapid collapsing of the vesicles. The rapid loss of the bilayer stability and the reorganization of the lipid molecules within ms support the argument that the transition mechanism is based on a leaky fusion of the vesicles

Extracellular matrix formation after transplantation of human embryonic stem cell-derived cardiomyocytes

Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells