Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity

Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN) gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions.     

Emotional and cognitive reinforcement of rat hippocampal long-term potentiation by different learning paradigms

In earlier studies we have shown that a protein-synthesis-independent, early, long-term potentiaton (early-LTP) that lasts up to 4-5 hours can be transformed (reinforced) into a protein-synthesis-dependent late-LTP that lasts > or = 8 hours by either an emotional challenge (e.g. swim stress) or mastering a cognitive task (e.g. spatial learning). In the present study we show that LTP-reinforcement by spatial training depends on the specific constraints of the learning paradigm. In a holeboard paradigm,LTP-reinforcement is related to the formation of a lasting reference memory whereas water-maze training gives more heterogenous results. Thus, cognitive aspects interfere with emotionally challenging components of the latter paradigm. These data indicate that different spatial-learning tasks are weighted distinctly by the animal. Thus, we show that aspects of specific spatial learning paradigms such as shifts of attention and emotional content directly influence functional plasticity and memory formation.     

High-risk HPV detection in specimens collected in SurePath preservative fluid: comparison of ambient and refrigerated storage

Objective:  With moves to introduce human papillomavirus (HPV) triage at sentinel sites in England, it is essential that optimal storage and transport conditions are determined for efficient HPV detection using residual liquid-based cytology specimens.
Methods:  Two cytology laboratories with comparable workloads sent residual cervical cytology specimens collected in BD Surepath™ Preservative Fluid to the Specialist Virology Centre for HPV testing. Storage and transport of specimens was at ambient (site A) or refrigerated (site R) temperatures. The effect of temperature on the ability to detect high-risk human papillomavirus (HR-HPV) using Digene Hybrid Capture^® 2 High-Risk HPV DNA Test (hc2) and Roche AMPLICOR^® HPV Test (AMPLICOR) was assessed. All specimens with discordant results were tested using Roche Linear Array HPV Genotyping test.
Results:  A total of 796 residual cytology specimens, with cytology ranging from normal to severe dyskaryosis, were provided (399 from site A and 397 from site R). Ambient storage and transit of cervical specimens in SurePath medium did not appear to affect significantly the suitability of the specimen for HPV testing, as measured by the concordance of the HR-HPV screening assays for ambient versus refrigerated specimens and by the proportion of specimens which tested invalid.
Conclusion:  Residual cytology specimens in SurePath medium, stored and transported at ambient temperature, appear suitable for HR-HPV detection by AMPLICOR beyond the manufacturer's recommended time and potentially up to four weeks.     

European guidelines for quality assurance in cervical cancer screening: recommendations for collecting samples for conventional and liquid-based cytology.

The current paper presents an annex in the second edition of the European Guidelines for Quality Assurance in Cervical Cancer Screening. It provides guidance on how to make a satisfactory conventional Pap smear or a liquid-based cytology (LBC) sample. Practitioners taking samples for cytology should first explain to the woman the purpose, the procedure and how the result will be communicated. Three sampling methods are considered as acceptable for preparing conventional Pap smears: (i) the cervical broom; (ii) the combination of a spatula and an endocervical brush; and (iii) the extended tip spatula. Smear takers should take care to sample the entire circumference of the transformation zone, to quickly spread the cellular material over a glass slide, and to fix the preparation within a few seconds to avoid drying artefacts. According to local guidelines, one of these three methods may be preferred. Sampling with a cotton tip applicator is inappropriate. Similar procedures should be followed for sampling cells for LBC, but only plastic devices may be used. The collected cells should be quickly transferred into a vial with fixative liquid according to the instructions of the manufacturer of the LBC system. Subsequently, the slide or vial and the completed request form are sent to the laboratory for cytological interpretation.     

Aluminum resistance in wheat involves maintenance of leaf Ca<Superscript>2+</Superscript> and Mg<Superscript>2+</Superscript> content,decreased lipid peroxidation and Al accumulation,and low photosystem II excitation pressure

The phytotoxic aluminum species (Al³⁺) is considered as the primary factor limiting crop productivity in over 40 % of world’s arable land that is acidic. We evaluated the responses of two wheat cultivars (Triticum aestivum L.) with differential Al resistance, cv. Yecora E (Al-resistant) and cv. Dio (Al-sensitive), exposed to 0, 37, 74 and 148 μM Al for 14 days in hydroponic culture at pH 4.5. With increasing Al concentration, leaf Ca²⁺ and Mg²⁺ content decreased, as well as the effective quantum yield of photosystem II (PSII) photochemistry (Φ _PSII ), while a gradual increase in leaf membrane lipid peroxidation, Al accumulation, photoinhibition (estimated as F _v /F _m ), and PSII excitation pressure (1 ? q _p ) occurred. However, the Al-resistant cultivar with lower Al accumulation, retained larger concentrations of Ca²⁺ and Mg²⁺ in the leaves and kept a larger fraction of the PSII reaction centres (RCs) in an open configuration, i.e. a higher ratio of oxidized to reduced quinone A (Q_A), than plants of the Al-sensitive cultivar. Four times higher Al concentration in the nutrient solution was required for Al-resistant plants (148 μM Al) than for Al-sensitive (37 μM Al), in order to establish the same closed RCs. Yet, the decline in photosynthetic efficiency in the cultivar Dio was not only due to closure of PSII RCs but also to a decrease in the quantum yield of the open RCs. We suggest that Al³⁺ toxicity may be mediated by nutrient deficiency and oxidative stress, and that Al-resistance of the wheat cultivar Yecora E, may be due at least partially, from the decreased Al accumulation that resulted to decreased reactive oxygen species (ROS) formation. However, under equal internal Al accumulation (exposure Al concentration: Dio 74 μM, Yecora E 148 μM) that resulted to the same oxidative stress, the reduced PSII excitation pressure and the better PSII functioning of the Al-resistant cultivar was probably due to the larger concentrations of Ca²⁺ and Mg²⁺ in the leaves. We propose that the different sensitivities of wheat cultivars to Al³⁺ toxicity can be correlated to differences in the redox state of Q_A. Thus, chlorophyll fluorescence measurements can be a promising tool for rapid screening of Al resistance in wheat cultivars.     

On brain activity mapping: insights and lessons from Brain Decoding Project to map memory patterns in the hippocampus

The BRAIN project recently announced by the president Obama is the reflection of unrelenting human quest for cracking the brain code, the patterns of neuronal activity that define who we are and what we are. While the Brain Activity Mapping proposal has rightly emphasized on the need to develop new technologies for measuring every spike from every neuron, it might be helpful to consider both the theoretical and experimental aspects that would accelerate our search for the organizing principles of the brain code. Here we share several insights and lessons from the similar proposal, namely, Brain Decoding Project that we initiated since 2007. We provide a specific example in our initial mapping of real-time memory traces from one part of the memory circuit, namely, the CA1 region of the mouse hippocampus. We show how innovative behavioral tasks and appropriate mathematical analyses of large datasets can play equally, if not more, important roles in uncovering the specific-to-general feature-coding cell assembly mechanism by which episodic memory, semantic knowledge, and imagination are generated and organized. Our own experiences suggest that the bottleneck of the Brain Project is not only at merely developing additional new technologies, but also the lack of efficient avenues to disseminate cutting edge platforms and decoding expertise to neuroscience community. Therefore, we propose that in order to harness unique insights and extensive knowledge from various investigators working in diverse neuroscience subfields, ranging from perception and emotion to memory and social behaviors, the BRAIN project should create a set of International and National Brain Decoding Centers at which cutting-edge recording technologies and expertise on analyzing large datasets analyses can be made readily available to the entire community of neuroscientists who can apply and schedule to perform cutting-edge research.