Experimental Infection of Rhesus Macaques and Common Marmosets with a European Strain of West Nile Virus

West Nile virus (WNV) is a mosquito-borne flavivirus that infects humans and other mammals. In some cases WNV causes severe neurological disease. During recent years, outbreaks of WNV are increasing in worldwide distribution and novel genetic variants of the virus have been detected. Although a substantial amount of data exists on WNV infections in rodent models, little is known about early events during WNV infection in primates, including humans. To gain a deeper understanding of this process, we performed experimental infections of rhesus macaques and common marmosets with a virulent European WNV strain (WNV-Ita09) and monitored virological, hematological, and biochemical parameters. WNV-Ita09 productively infected both monkey species, with higher replication and wider tissue distribution in common marmosets compared to rhesus macaques. The animals in this study however, did not develop clinical signs of WNV disease, nor showed substantial deviations in clinical laboratory parameters. In both species, the virus induced a rapid CD56^dimCD16^bright natural killer response, followed by IgM and IgG antibody responses. The results of this study show that healthy rhesus macaques and common marmosets are promising animal models to study WNV-Ita09 infection. Both models may be particularly of use to evaluate potential vaccine candidates or to investigate WNV pathogenesis.     

Anti Human Fibronectin–Gold Nanoparticle Complex,a Potential Nanobiosensor Tool for Detection of Fibronectin in ECM of Cultured Cells

Specific protein detection by means of antibody-nanoparticle conjugates is a new field in medical nanobiotechnology. Among many nanoparticles used, gold nanoparticles show strong light-absorption properties which have been exploited in designing nanobiosensors. Fibronectin (FN) plays an important role in extracellular matrix (ECM) structure and function of normal cells; however, in conditions like lung carcinoma, its expression increases, especially in non small cell lung carcinoma (NSCLC). In this study, we conjugated gold nanoparticles to human fibronectin antibody (anti-hFN) to design a colorimetric nanobiosensor for detection of FN present in ECM of cultured cells. Three different cell lines, namely A549 (target cells), AGO-1522 (control cells), and Nalm-6 (negative control cells), were used to compare changes in color resulting from aggregation of gold nanoparticles due to higher amount of FN. Our construct was able to detect increased level of FN which was distinguishable visually by change in color and could be confirmed by spectrophotometer as well.     

Herbivore-induced indirect defense across bean cultivars is independent of their degree of direct resistance

We tested the extent to which resistance of common bean (Phaseolus vulgaris) cultivars to the spider mite Tetranychus urticae parallels the extent to which these plants display indirect defenses via the induced attraction of the predatory mite Phytoseiulus persimilis. First, via field and greenhouse trials on 19 commercial bean cultivars, we selected two spider mite-resistant (Naz and Ks41128) and two susceptible (Akthar and G11867) cultivars and measured the spider mite-induced volatiles and the subsequently induced attraction of predatory mites via olfactory choice assays. The two major volatiles, 4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) and (Z)-3-hexenyl-acetate, were induced in the resistant but not in the susceptible cultivars. However, uninfested susceptible cultivars emitted these volatiles at levels similar to those of mite-infested resistant cultivars. Significant induction of several minor components was observed for all four cultivars except for the infested-susceptible cultivar G11867. Both, the spider mite-resistant cultivar Naz and the susceptible cultivar G11867, attracted more predatory mites when they were infested. In contrast, spider mites induced increased emission of two major and five minor volatiles in Ks41128, but predatory mites did not discriminate between infested and uninfested plants. Overall, the attraction of predatory mites appeared to correlate positively with the presence of TMTT and (Z)-3-hexenyl acetate and negatively with β-caryophyllene and α-pinene in the bean headspace. Taken together, our data suggest that resistance and attraction of natural enemies via induced volatiles are independent traits. We argue that it should be possible to cross predator-attraction promoting traits into resistant cultivars that lack sufficiently inducible indirect defenses.     

Protein tyrosine phosphatase 1B (PTP1B) is required for cardiac lineage differentiation of mouse embryonic stem cells

Protein tyrosine phosphatase 1B (PTP1B) has been shown to regulate multiple cellular events such as differentiation, cell growth, and proliferation; however, the role of PTP1B in differentiation of embryonic stem (ES) cells into cardiomyocytes remains unexplored. In the present study, we investigated the effects of PTP1B inhibition on differentiation of ES cells into cardiomyocytes. PTP1B mRNA and protein levels were increased during the differentiation of ES cells into cardiomyocytes. Accordingly, a stable ES cell line expressing PTP1B shRNA was established. In vitro, the number and size of spontaneously beating embryoid bodies were significantly decreased in PTP1B-knockdown cells, compared with the control cells. Decreased expression of cardiac-specific markers Nkx2-5, MHC-α, cTnT, and CX43, as assessed by real-time PCR analysis, was further confirmed by immunocytochemistry of the markers. The results also showed that PTP1B inhibition induced apoptosis in both differentiated and undifferentiated ES cells, as presented by increasing the level of cleaved caspase-3, cytochrome C, and cleaved PARP. Further analyses revealed that PTP1B inhibition did not change proliferation and pluripotency of undifferentiated ES cells. Taken together, the data presented here suggest that PTP1B is essential for proper differentiation of ES cells into cardiomyocytes.     

Parasitic plant small RNA analyses unveil parasite-specific signatures of microRNA retention,loss, and gain

Parasitism is a successful life strategy that has evolved independently in several families of vascular plants. The genera Cuscuta and Orobanche represent examples of the two profoundly different groups of parasites: one parasitizing host shoots and the other infecting host roots. In this study, we sequenced and described the overall repertoire of small RNAs from Cuscuta campestris and Orobanche aegyptiaca. We showed that C. campestris contains a number of novel microRNAs (miRNAs) in addition to a conspicuous retention of miRNAs that are typically lacking in other Solanales, while several typically conserved miRNAs seem to have become obsolete in the parasite. One new miRNA appears to be derived from a horizontal gene transfer event. The exploratory analysis of the miRNA population (exploratory due to the absence of a full genomic sequence for reference) from the root parasitic O. aegyptiaca also revealed a loss of a number of miRNAs compared to photosynthetic species from the same order. In summary, our study shows partly similar evolutionary signatures in the RNA silencing machinery in both parasites. Our data bear proof for the dynamism of this regulatory mechanism in parasitic plants.

MicroRNAs in parasitic plants reflect their lifestyle.     

Interference competition between Aphidius matricariae and Praon volucre (Hymenoptera: Braconidae) attacking two common aphid species

Interference competition is a common phenomenon that occurs among adult females of different species to gain the highest food resources at the same time. In this research, extrinsic competition between Aphidius matricariae and Praon volucre on different densities and stages of two important pests of greenhouse crops in the world, Aphis gossypii and Myzus persicae, were investigated. The results of this study showed that total percentage parasitism of second, third and fourth nymphal instars of A. gossypii and M. persicae by A. matricariae, and P. volucre were affected by extrinsic competition. A combination of A. matricariae and P. volucre on A. gossypii had a negative effect on performance of these parasitoids. Although extrinsic competition reduced the efficiency of A. matricariae and P. volucre on M. persicae, total parasitism of M. persicae by A. matricariae and P. volucre (combination of two parasitoids) increased compared to A. matricariae or P. volucre acting alone. Also the results indicated that the extrinsic competition between A. matricariae and P. volucre on both A. gossypii and M. persicae was apparently more intense when presented with 25 hosts compared to 50 and 100 hosts. The results of this research show important information to determine an appropriate combination of these two parasitoid wasps for biological control of A. gossypii and M. persicae in greenhouses.     

New data on the spider fauna of Iran (Arachnida: Araneae)

We present the results of some spider surveys that were conducted in different parts of Iran. Faunistic records for 30 species which are new to Iran are presented here. Biogeographic data are provided for each species. Two families, namely Liocranidae and Mimetidae, are recorded for the first time from the country.     

The influence of salinity on cell ultrastructures and photosynthetic apparatus of barley genotypes differing in salt stress tolerance

A hydroponic experiment was conducted to elucidate the difference in growth and cell ultrastructure between Tibetan wild and cultivated barley genotypes under moderate (150 mM NaCl) and high (300 mM NaCl) salt stress. The growth of three barley genotypes was reduced significantly under salt stress, but the wild barley XZ16 (tolerant) was less affected relative to cultivated barley Yerong (moderate tolerant) and Gairdner (sensitive). Meanwhile, XZ16 had lower Na⁺ and higher K⁺ concentrations in leaves than other two genotypes. In terms of photosynthetic and chlorophyll fluorescence parameters, salt stress reduced maximal photochemical efficiency (F _v/F _m), net photosynthetic rate (Pn), stomatal conductance (Gs), and intracellular CO₂ concentration (Ci). XZ16 showed relatively smaller reduction in comparison with the two cultivated barley genotypes. The observation of transmission electron microscopy found that fundamental cell ultrastructure changes happened in both leaves and roots of all barley genotypes under salt NaCl stress, with chloroplasts being most changed. Moreover, obvious difference could be detected among the three genotypes in the damage of cell ultrastructure under salt stress, with XZ16 and Gairdner being least and most affected, respectively. It may be concluded that high salt tolerance in XZ16 is attributed to less Na⁺ accumulation and K⁺ reduction in leaves, more slight damage in cell ultrastructure, which in turn caused less influence on chloroplast function and photosynthesis.     

Biodiversity and community structure of Late Pleistocene foraminifera from Kish Island, Persian Gulf (Iran)

The raised coral reef sequences at Kish Island provide a rare window into the depositional setting and paleoenvironment of a high-latitude, shallow-water coral reef that developed under turbid conditions in the Persian Gulf during Marine Isotope Stage 7 (~200 to 250?ka). Six sedimentary facies and eight foraminiferal assemblages can be identified throughout the sequence. A ninth assemblage can be defined for the modern subtidal realm. At the base of the sequence is a marl rich in hyaline foraminifera (Elphidium, Ammonia, Asterorotalia, Bulimina, Nonion, and Quinqueloculina) and ostracods, which was deposited in about 30–40?m water depth in a turbid deltaic setting. Shallowing resulted in the marl becoming sandy, and changing to a mollusc-rich facies with rare foraminifera (mostly smaller miliolid taxa) that formed the substrate for coral recruitment. The coral marl layer contains many large corals embedded in situ in an aggregate and coralline algae-rich marl. Two abundance peaks in the foraminifera occur at the base and mid-way through this layer, which also correspond to a change from Murrayinella-dominated to Placopsilina-dominated assemblages, indicating deepening and more open-marine conditions, but elevated turbidity. Towards the top of the layer, abundance of foraminifera decreases and miliolid foraminifera become dominant. The top-most layer is dominated by coral and mollusc fragments and has an Amphistegina-rich reef-related assemblage. Of the Late Pleistocene foraminiferal assemblages, the Murrayinella-, Pararotalia-, and Placopsilina-dominated assemblages are no longer present in the modern gulf for unknown reasons. Of the other five assemblages, only the Amphistegina assemblage is found within proximity to the modern Kish Island. The Elphidium and Asterorotalia-Bulimina assemblages are from deeper areas of the gulf. The Ammonia and Quinqueloculina assemblages occur in lagoonal sediments on the Arabian side of the gulf. Like the modern Persian Gulf, the diversity of foraminifera was low (~80 common species) during the Pleistocene and does not correlate with foraminiferal abundance.     

Influence of Plasma Processing on Recovery and Analysis of Circulating Nucleic Acids

Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer. However there is wide variation in blood processing and methods for isolation of circulating free DNA (cfDNA) and microRNAs (miRNAs). Here we compare the extraction efficiency and reproducibility of 4 commercially available kits for cfDNA and 3 for miRNA using spike-in of reference templates. We also compare the effects of increasing time between venepuncture and centrifugation and differential centrifugation force on recovery of CNAs. cfDNA was quantified by TaqMan qPCR and targeted deep sequencing. miRNA profiles were assessed with TaqMan low-density arrays and assays. The QIAamp^® DNA Blood Mini and Circulating nucleic acid kits gave the highest recovery of cfDNA and efficient recovery (>90%) of a 564bp spike-in. Moreover, targeted sequencing revealed overlapping cfDNA profiles and variant depth, including detection of HER2 gene amplification, using the Ion AmpliSeq™Cancer Hotspot Panel v2. Highest yields of miRNA and the synthetic Arabidopsis thaliana miR-159a spike-in were obtained using the miRNeasy Serum/Plasma kit, with saturation above 200 µl of plasma. miRNA profiles showed significant variation with increasing time before centrifugation (p<0.001) and increasing centrifugation force, with depletion of platelet associated miRNAs, whereas cfDNA was unaffected. However, sample replicates showed excellent reproducibility on TaqMan low density arrays (ρ = 0.96, p<0.0001). We also successfully generated miRNA profiles for plasma samples stored > 12 years, highlighting the potential for analysis of stored sample biobanks. In the era of the liquid biopsy, standardisation of methods is required to minimise variation, particularly for miRNA.