Alterations of Red Cell Membrane Properties in Nneuroacanthocytosis

Neuroacanthocytosis (NA) refers to a group of heterogenous, rare genetic disorders, namely chorea acanthocytosis (ChAc), McLeod syndrome (MLS), Huntington’s disease-like 2 (HDL2) and pantothenate kinase associated neurodegeneration (PKAN), that mainly affect the basal ganglia and are associated with similar neurological symptoms. PKAN is also assigned to a group of rare neurodegenerative diseases, known as NBIA (neurodegeneration with brain iron accumulation), associated with iron accumulation in the basal ganglia and progressive movement disorder. Acanthocytosis, the occurrence of misshaped erythrocytes with thorny protrusions, is frequently observed in ChAc and MLS patients but less prevalent in PKAN (about 10%) and HDL2 patients. The pathological factors that lead to the formation of the acanthocytic red blood cell shape are currently unknown. The aim of this study was to determine whether NA/NBIA acanthocytes differ in their functionality from normal erythrocytes. Several flow-cytometry-based assays were applied to test the physiological responses of the plasma membrane, namely drug-induced endocytosis, phosphatidylserine exposure and calcium uptake upon treatment with lysophosphatidic acid. ChAc red cell samples clearly showed a reduced response in drug-induced endovesiculation, lysophosphatidic acid-induced phosphatidylserine exposure, and calcium uptake. Impaired responses were also observed in acanthocyte-positive NBIA (PKAN) red cells but not in patient cells without shape abnormalities. These data suggest an “acanthocytic state” of the red cell where alterations in functional and interdependent membrane properties arise together with an acanthocytic cell shape. Further elucidation of the aberrant molecular mechanisms that cause this acanthocytic state may possibly help to evaluate the pathological pathways leading to neurodegeneration.     

Fitness Consequences of Northward Dispersal as Possible Adaptation to Climate Change,Using Experimental Translocation of a Migratory Passerine

Climate change leads to rapid, differential changes in phenology across trophic levels, often resulting in temporal mismatches between predators and their prey. If a species cannot easily adjust its timing, it can adapt by choosing a new breeding location with a later phenology of its prey. In this study, we experimentally investigated whether long-distance dispersal to northern breeding grounds with a later phenology could be a feasible process to restore the match between timing of breeding and peak food abundance and thus improve reproductive success. Here, we report the successful translocation of pied flycatchers (Ficedula hypoleuca) to natural breeding sites 560 km to the Northeast. We expected translocated birds to have a fitness advantage with respect to environmental phenology, but to potentially pay costs through the lack of other locally adapted traits. Translocated individuals started egg laying 11 days earlier than northern control birds, which were translocated only within the northern site. The number of fledglings produced was somewhat lower in translocated birds, compared to northern controls, and fledglings were in lower body condition. Translocated individuals were performing not significantly different to control birds that remained at the original southern site. The lack of advantage of the translocated individuals most likely resulted from the exceptionally cold spring in which the experiment was carried out. Our results, however, suggest that pied flycatchers can successfully introduce their early breeding phenotype after dispersing to more northern areas, and thus that adaptation through dispersal is a viable option for populations that get locally maladapted through climate change.     

Is electric fencing an efficient and animal-friendly tool to prevent stone martens from entering buildings?

Wildlife such as stone martens Martes foina have adapted to live in urban areas, which are spreading worldwide. Conflicts with humans can arise when martens enter buildings and cause serious damage to roof insulation. Therefore, there is an increasing demand for measures that will reduce such human–wildlife conflicts. Data we collected from a big insurance company regarding the costs of repairs of damages caused by martens revealed an estimate of 655 annual cases per Mio inhabitants and pay-outs of approximately €200,000 per year from 2002 to 2006. The data collected from pest control organisations showed an increase of damage claims from around 20 up to 150 cases per year in the last 20 years. In an experimental case study, the analysis of video recordings (26 nights) and long-term bait controls (103 nights) showed that installed electric wires and woven wire mesh prevented martens from entering a building they previously used intensively. Our results suggest that electric fencing could be a simple, short-termed measure to exclude martens from buildings before definitively sealing the openings. Electric fencing needs further quantitative and qualitative evaluation at different study sites to develop an animal-friendly, practical and cost-effective tool that prevents martens from causing damage to roof insulations.     

Fully Plastic Dye Solar Cell Devices by Low‐Temperature UV‐Irradiation of both the Mesoporous TiO2 Photo‐ and Platinized Counter‐Electrodes

The application of UV irradiation processes are successfully proposed for the first time in the fabrication of both of the two plastic electrodes in flexible dye solar cells (DSCs) and modules. For the realization of the photo‐electrode, a customized TiO₂ paste formulation and UV processing method was developed which yields 134% (48%) performance enhancement with respect to the same (binder‐free) paste treated at 120 °C. UV treatment induces both complete removal of organic media and more efficient charge collection. Significantly, highly catalytic platinized flexible counter‐electrodes are also obtained via UV photo‐induced reduction of screen‐printed platinum precursor pastes based on hexachloroplatinic acid. Using both UV‐processed electrodes, a fully plastic DSC is fabricated with a conversion efficiency of 4.3% under 1 Sun (semitransparent) and 5.3% under 0.2 Sun (opaque). Performance is within 10% of the efficiency of a glass‐based DSC prepared with the same materials but with conventional high temperature processes. The material formulations and processes are simple, and easily up‐scaled over large areas, even directly and simultaneously applicable to the preparation of both the photo‐and counter‐electrode on the same substrate which enabled us to demonstrate the first module on plastic realized with a W series interconnection.     

Quantitative DNA methylation analysis improves epigenotype-phenotype correlations in Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is a rare disorder characterized by overgrowth and predisposition to embryonal tumors. BWS is caused by various epigenetic and/or genetic alterations that dysregulate the imprinted genes on chromosome region 11p15.5. Molecular analysis is required to reinforce the clinical diagnosis of BWS and to identify BWS patients with cancer susceptibility. This is particularly crucial prenatally because most signs of BWS cannot be recognized in utero. We established a reliable molecular assay by pyrosequencing to quantitatively evaluate the methylation profiles of ICR1 and ICR2. We explored epigenotype-phenotype correlations in 19 patients that fulfilled the clinical diagnostic criteria for BWS, 22 patients with suspected BWS, and three fetuses with omphalocele. Abnormal methylation was observed in one prenatal case and 19 postnatal cases, including seven suspected BWS. Seven cases showed ICR1 hypermethylation, five cases showed ICR2 hypomethylation, and eight cases showed abnormal methylation of ICR1 and ICR2 indicating paternal uniparental disomy (UPD). More cases of ICR1 alterations and UPD were found than expected. This is likely due to the sensitivity of this approach, which can detect slight deviations in methylation from normal levels. There was a significant correlation (p < 0.001) between the percentage of ICR1 methylation and BWS features: severe hypermethylation (range: 75–86%) was associated with macroglossia, macrosomia, and visceromegaly, whereas mild hypermethylation (range: 55–59%) was associated with umbilical hernia and diastasis recti. Evaluation of ICR1 and ICR2 methylation by pyrosequencing in BWS can improve epigenotype-phenotype correlations, detection of methylation alterations in suspected cases, and identification of UPD.     

Are drought-resistance promoting bacteria cross-compatible with different plant models?

The association between plant and plant growth promoting bacteria (PGPB) contributes to the successful thriving of plants in extreme environments featured by water shortage. We have recently shown that, with respect to the non-cultivated desert soil, the rhizosphere of pepper plants cultivated under desert farming hosts PGPB communities that are endowed with a large portfolio of PGP traits. Pepper plants exposed to bacterial isolates from plants cultivated under desert farming exhibited a higher tolerance to water shortage, compared with untreated control. This promotion was mediated by a larger root system (up to 40%), stimulated by the bacteria, that enhanced plant ability to uptake water from dry soil. We provide initial evidence that the nature of the interaction can have a limited level of specificity and that PGPB isolates may determine resistance to water stress in plants others than the one of the original isolation. It is apparent that, in relation to plant resistance to water stress, a feature of primary evolutionary importance for all plants, a cross-compatibility between PGPB and different plant models exists at least on a short-term.     

Low genetic diversity of a high mountain burnet moth species in the Pyrenees

The burnet moth Zygaena anthyllidis, endemic to the high elevations of the Pyrenees, is vulnerable to land-use. In order to identify conservation priorities based on an assessment of genetic diversity within populations and gene flow among populations, we examined Z. anthyllidis’ genetic variability and differentiation based on allozyme electrophoresis from seven populations scattered across its entire range. In comparison to other mountain Lepidoptera, the populations studied exhibit a low level of genetic diversity. Remarkable between-population differentiation (F _ST = 0.053), the presence of private alleles, and the lack of significant isolation-by-distance pattern characterises the genetic make-up of the species. We interpreted the pattern of genetic differentiation as a consequence of low dispersal power in combination with insufficient landscape connectivity. Ongoing land-use change might reinforce genetic differentiation due to habitat fragmentation and additionally affect negatively allozyme variability at shifting range margins, i.e. the capacity to adapt to changing environments. We therefore suggest creating a network of suitable habitats at the landscape scale to facilitate genetic exchange and to conserve the species’ overall genetic variability.     

Increased Maternal Genome Dosage Bypasses the Requirement of the FIS Polycomb Repressive Complex 2 in Arabidopsis Seed Development

Seed development in flowering plants is initiated after a double fertilization event with two sperm cells fertilizing two female gametes, the egg cell and the central cell, leading to the formation of embryo and endosperm, respectively. In most species the endosperm is a polyploid tissue inheriting two maternal genomes and one paternal genome. As a consequence of this particular genomic configuration the endosperm is a dosage sensitive tissue, and changes in the ratio of maternal to paternal contributions strongly impact on endosperm development. The FERTILIZATION INDEPENDENT SEED (FIS) Polycomb Repressive Complex 2 (PRC2) is essential for endosperm development; however, the underlying forces that led to the evolution of the FIS-PRC2 remained unknown. Here, we show that the functional requirement of the FIS-PRC2 can be bypassed by increasing the ratio of maternal to paternal genomes in the endosperm, suggesting that the main functional requirement of the FIS-PRC2 is to balance parental genome contributions and to reduce genetic conflict. We furthermore reveal that the AGAMOUS LIKE (AGL) gene AGL62 acts as a dosage-sensitive seed size regulator and that reduced expression of AGL62 might be responsible for reduced size of seeds with increased maternal genome dosage.