Tracking mite trophic interactions by multiplex PCR

BACKGROUND A thorough knowledge of trophic webs in agroecosystems is essential to achieve successful biological pest control. Phytoseiid mites are the most efficient natural enemies of tetranychid mites, which include several important pests worldwide. Nevertheless, phytoseiids may feed on other food sources including other microarthropods, plants and even other phytoseiids (intraguild predation), which can interfere with biological control services. Molecular gut content analysis is a valuable tool for characterizing trophic interactions, mainly when working on microarthropods such as mites. We have designed new primers for Phytoseiidae, Tetranychidae and Thysanoptera identification and they have been multiplexed in a polymerase chain reaction (PCR) together with universal plant primers. Additionally, we have estimated prey DNA detectability success over time (DS50) considering the most probable events in Spanish citrus orchards: the phytoseiid Euseius stipulatus as a predator, the phytoseiid Phytoseiulus persimilis as intraguild prey, and the thrips Frankliniella occidentalis and Anaphothrips obscurus as alternative prey to Tetranychus urticae. RESULTS The designed multiplex PCR allows the identification of phytoseiids (both predator and intraguild prey) and detects alternative food sources mentioned above in the gut of the phytoseiid predator. DS50 for E. stipulatus as the predator were 1.3, 2.3 and 18.7 h post feeding for F. occidentalis, A. obscurus and P. persimilis as prey, respectively. CONCLUSION Tracking of the trophic relationships within the citrus acarofauna, and the unveiling of the role of alternative food sources will pave the way for enhancing T. urticae biological control. This multiplex PCR approach could be applicable for these purposes in similar agroecosystems

Distinct Functions for Mammalian CLASP1 and-2 During Neurite and Axon Elongation

Mammalian cytoplasmic linker associated protein 1 and -2 (CLASP1 and -2) are microtubule (MT) plus-end tracking proteins that selectively stabilize MTs at the edge of cells and that promote MT nucleation and growth at the Golgi, thereby sustaining cell polarity. In vitro analysis has shown that CLASPs are MT growth promoting factors. To date, a single CLASP1 isoform (called CLASP1α) has been described, whereas three CLASP2 isoforms are known (CLASP2α, -β, and -γ). Although CLASP2β/γ are enriched in neurons, suggesting isoform-specific functions, it has been proposed that during neurite outgrowth CLASP1 and -2 act in a redundant fashion by modulating MT dynamics downstream of glycogen synthase kinase 3 (GSK3). Here, we show that in differentiating N1E-115 neuroblastoma cells CLASP1 and CLASP2 differ in their accumulation at MT plus-ends and display different sensitivity to GSK3-mediated phosphorylation, and hence regulation. More specifically, western blot (WB) analysis suggests that pharmacological inhibition of GSK3 affects CLASP2 but not CLASP1 phosphorylation and fluorescence-based microscopy data show that GSK3 inhibition leads to an increase in the number of CLASP2-decorated MT ends, as well as to increased CLASP2 staining of individual MT ends, whereas a reduction in the number of CLASP1-decorated ends is observed. Thus, in N1E-115 cells CLASP2 appears to be a prominent target of GSK3 while CLASP1 is less sensitive. Surprisingly, knockdown of either CLASP causes phosphorylation of GSK3, pointing to the existence of feedback loops between CLASPs and GSK3. In addition, CLASP2 depletion also leads to the activation of protein kinase C (PKC). We found that these differences correlate with opposite functions of CLASP1 and CLASP2 during neuronal differentiation, i.e., CLASP1 stimulates neurite extension, whereas CLASP2 inhibits it. Consistent with knockdown results in N1E-115 cells, primary Clasp2 knockout (KO) neurons exhibit early accelerated neurite and axon outgrowth, showing longer axons than control neurons. We propose a model in which neurite outgrowth is fine-tuned by differentially posttranslationally modified isoforms of CLASPs acting at distinct intracellular locations, thereby targeting MT stabilizing activities of the CLASPs and controlling feedback signaling towards upstream kinases. In summary, our findings provide new insight into the roles of neuronal CLASPs, which emerge as regulators acting in different signaling pathways and locally modulating MT behavior during neurite/axon outgrowth

A space–time Trefftz discontinuous Galerkin method for the acoustic wave equation in first-order formulation

We introduce a space–time Trefftz discontinuous Galerkin method for the first-order transient acoustic wave equations in arbitrary space dimensions, extending the one-dimensional scheme of Kretzschmar et al. (IMA J Numer Anal 36:1599–1635, 2016). Test and trial discrete functions are space–time piecewise polynomial solutions of the wave equations. We prove well-posedness and a priori error bounds in both skeleton-based and mesh-independent norms. The space–time formulation corresponds to an implicit time-stepping scheme, if posed on meshes partitioned in time slabs, or to an explicit scheme, if posed on “tent-pitched” meshes. We describe two Trefftz polynomial discrete spaces, introduce bases for them and prove optimal, high-order h-convergence bounds

Tau Structures

Tau is a microtubule-associated protein that plays an important role in axonal stabilization, neuronal development, and neuronal polarity. In this review, we focus on the primary, secondary, tertiary, and quaternary tau structures. We describe the structure of tau from its specific residues until its conformation in dimers, oligomers, and larger polymers in physiological and pathological situations

Pacientes españoles con síndrome de hipoventilación central incluidos en el Registro europeo. Datos del 2015

Introducción El síndrome de hipoventilación central congénita (SHCC) es una enfermedad genética muy rara causada por mutaciones en PHOX2B; en 2010 se creó el Consorcio Europeo del Síndrome de Hipoventilación Central, que en 2012 implantó un Registro online de pacientes para optimizar su cuidado. Objetivo Conocer las características y la evolución de los pacientes españoles con SHCC y detectar áreas de mejora. Materiales y método Se analizaron los datos actualizados en diciembre del 2015 de los pacientes españoles del Registro europeo. Resultados Se registró a 38 pacientes, nacidos entre 1987 y 2013, procedentes de 18 hospitales. El 34, 2% eran mayores de 18 años. Han fallecido 3 pacientes. Aportaban estudio del gen PHOX2B 37 (97, 3%), 32 (86, 5%) con mutación. Los genotipos 20/25, 20/26 y 20/27 representaron el 84, 3% de las mutaciones. Las disautonomías fueron más frecuentes y graves en portadores de genotipos con mayores expansiones de polialaninas. El 47% de pacientes asociaba alteraciones oculares, el 16% Hirschsprung, el 13% hipoglucemias y el 5% tumores. Treinta pacientes (79%) debutaron en el periodo neonatal y 8 (21%) posteriormente (inicio/diagnóstico tardío). Ocho niños (21%) recibieron inicialmente ventilación domiciliaria con mascarilla; 5 eran lactantes con comienzo neonatal, 2 de ellos precisaron cambio a traqueostomía tras presentar parada cardiorrespiratoria; ambos tenían mutaciones graves. Han sido decanulados y transferidos a mascarilla el 34, 3% de los pacientes (edad media: 13, 7 años). El 29, 4% de los niños escolarizados precisaron refuerzo educativo. Conclusión La implementación del Registro en España de pacientes con SHCC ha permitido identificar aspectos relevantes para optimizar sus cuidados, tales como la importancia del estudio genético para el diagnóstico y la estimación de gravedad, la frecuencia elevada de alteraciones oculares y de necesidad de refuerzo educativo, y algunas limitaciones de las técnicas ventilatorias. Introduction Congenital Central Hypoventilation Syndrome (CCHS) is a very rare genetic disease. In 2012 the European Central Hypoventilation Syndrome (EuCHS) Consortium created an online patient registry in order to improve care. Aim To determine the characteristics and outcomes of Spanish patients with CCHS, and detect clinical areas for improvement. Materials and method An assessment was made on the data from Spanish patients in the European Registry, updated on December 2015. Results The Registry contained 38 patients, born between 1987 and 2013, in 18 hospitals. Thirteen (34.2%) were older than 18 years. Three patients had died. Genetic analysis identified PHOX2B mutations in 32 (86.5%) out of 37 patients assessed. The 20/25, 20/26 and 20/27 polyalanine repeat mutations (PARMs) represented 84.3% of all mutations. Longer PARMs had more, as well as more severe, autonomic dysfunctions. Eye diseases were present in 47%, with 16% having Hirschsprung disease, 13% with hypoglycaemia, and 5% with tumours. Thirty patients (79%) required ventilation from the neonatal period onwards, and 8 (21%) later on in life (late onset/presentation). Eight children (21%) were using mask ventilation at the first home discharge. Five of them were infants with neonatal onset, two of them, both having a severe mutation, were switched to tracheostomy after cardiorespiratory arrest at home. Approximately one-third (34.3%) of patients were de-cannulated and switched to mask ventilation at a mean age of 13.7 years. Educational reinforcement was required in 29.4% of children attending school. Conclusion The implementation of the EuCHS Registry in Spain has identified some relevant issues for optimising healthcare, such as the importance of genetic study for diagnosis and assessment of severity, the high frequency of eye disease and educational reinforcement, as well as some limitations in ventilatory techniques