Detection of Iris yellow spot virus (IYSV) in selected Allium species and overwintering hosts in Austrian onion-producing areas

Das Iris yellow spot virus (IYSV) wurde erstmals 1989 in den USA nachgewiesen. IYSV konnte in den letzten Jahren in den meisten Zwiebelanbauregionen der Vereinigten Staaten und vielen anderen Ländern nachgewiesen werden. Der wirtschaftlich bedeutendste Wirt ist die Zwiebel (Allium cepa). Der Erstnachweis in Europa und eine detaillierte Beschreibung erfolgte 1998 an Iris hollandica in den Niederlanden. Kurz danach konnte ein Befall an Zwiebel in Israel nachgewiesen werden. In Österreich wurde das IYSV erstmals im Sommer 2009 nachgewiesen. Das Virus wird nicht mit dem Saatgut übertragen, konnte jedoch in Zwiebelbulben nachgewiesen werden. Während der Vegetation erfolgt die Übertragung durch den Zwiebelthrips (Thrips tabaci). In Österreich konnte das IYSV in allen Zwiebelanbauregionen mit dem DAS-ELISA nachgewiesen werden. Des Weiteren erfolgte ein Erstnachweis von IYSV an Porree für Österreich. Darüber hinaus konnte auch ein Befall in einer Zwiebelbulbe nachgewiesen werden (es ist dies weltweit der dritte und für Europa der zweite derartige Nachweis). Der Stellenwert von infizierten Unkräutern als Überdauerungs- oder Verbreitungsorgane ist bis heute ungeklärt. Das Virus konnte an elf Unkrautarten mit dem DAS-ELISA-Verfahren bestätigt werden, davon stellen sechs Arten nach dieser Methode neue Wirte von IYSV dar. Mit der RT-PCR konnte es an Unkräutern nicht nachgewiesen werden.    Iris yellow spot virus (IYSV) has been reported for the first time in USA in 1989. Rapid spread of this viral pathogen has occurred in the western United States. IYSV has been frequently reported from most onion-production regions of the United States and many areas of the world in recent years. In 1998 it has been reported for the first time for Europe, in the Netherlands on Iris hollandica. Shortly afterwards it could be detected on onion in Israel. In Austria the first report of IYSV occurred in 2009. It is not seed born and only vectored by onion thrips (Thrips tabaci). As a result of our investigations all onion-producing areas in Austria tested positive for IYSV with DAS-ELISA in 2010. Leek has been tested IYSV-positive for the first time in Austria. Additionally IYSV could be detected in onion bulbs, which represents the third report worldwide and the second for Europe. The influence of weed hosts for the overwintering and distribution of the virus are undetermined to date. Eleven weed species have tested positive using DAS-ELISA, six species have been found out to be new hosts for IYSV according to this method. Nevertheless, none have been confirmed using the RT-PCR.   &nbsp

Microguards and micromessengers of the genome

The regulation of gene expression is of fundamental importance to maintain organismal function and integrity and requires a multifaceted and highly ordered sequence of events. The cyclic nature of gene expression is known as ‘transcription dynamics’. Disruption or perturbation of these dynamics can result in significant fitness costs arising from genome instability, accelerated ageing and disease. We review recent research that supports the idea that an important new role for small RNAs, particularly microRNAs (miRNAs), is in protecting the genome against short-term transcriptional fluctuations, in a process we term ‘microguarding’. An additional emerging role for miRNAs is as ‘micromessengers’—through alteration of gene expression in target cells to which they are trafficked within microvesicles. We describe the scant but emerging evidence that miRNAs can be moved between different cells, individuals and even species, to exert biologically significant responses. With these two new roles, miRNAs have the potential to protect against deleterious gene expression variation from perturbation and to themselves perturb the expression of genes in target cells. These interactions between cells will frequently be subject to conflicts of interest when they occur between unrelated cells that lack a coincidence of fitness interests. Hence, there is the potential for miRNAs to represent both a means to resolve conflicts of interest, as well as instigate them. We conclude by exploring this conflict hypothesis, by describing some of the initial evidence consistent with it and proposing new ideas for future research into this exciting topic

Developing a toolkit for the assessment and monitoring of musculoskeletal ageing

The complexities and heterogeneity of the ageing process have slowed the development of consensus on appropriate biomarkers of healthy ageing. The Medical Research Council–Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing (CIMA) is a collaboration between researchers and clinicians at the Universities of Liverpool, Sheffield and Newcastle. One of CIMA’s objectives is to ‘Identify and share optimal techniques and approaches to monitor age-related changes in all musculoskeletal tissues, and to provide an integrated assessment of musculoskeletal function’—in other words to develop a toolkit for assessing musculoskeletal ageing. This toolkit is envisaged as an instrument that can be used to characterise and quantify musculoskeletal function during ‘normal’ ageing, lend itself to use in large-scale, internationally important cohorts, and provide a set of biomarker outcome measures for epidemiological and intervention studies designed to enhance healthy musculoskeletal ageing. Such potential biomarkers include: biochemical measurements in biofluids or tissue samples, in vivo measurements of body composition, imaging of structural and physical properties, and functional tests. This review assesses candidate biomarkers of musculoskeletal ageing under these four headings, details their biological bases, strengths and limitations, and makes practical recommendations for their use. In addition, we identify gaps in the evidence base and priorities for further research on biomarkers of musculoskeletal ageing

Circulating microRNAs as potential diagnostic biomarkers for osteoporosis

Osteoporosis is the most common age-related bone disease worldwide and is usually clinically asymptomatic until the first fracture happens. MicroRNAs are critical molecular regulators in bone remodelling processes and are stabilised in the blood. The aim of this project was to identify circulatory microRNAs associated with osteoporosis using advanced PCR arrays initially and the identified differentially-expressed microRNAs were validated in clinical samples using RT-qPCR. A total of 161participants were recruited and 139 participants were included in this study with local ethical approvals prior to recruitment. RNAs were extracted, purified, quantified and analysed from all serum and plasma samples. Differentially-expressed miRNAs were identified using miRNA PCR arrays initially and validated in 139 serum and 134 plasma clinical samples using RT-qPCR. Following validation of identified miRNAs in individual clinical samples using RT-qPCR, circulating miRNAs, hsa-miR-122-5p and hsa-miR-4516 were statistically significantly differentially-expressed between non-osteoporotic controls, osteopaenia and osteoporosis patients. Further analysis showed that the levels of these microRNAs were associated with fragility fracture and correlated with the low bone mineral density in osteoporosis patients. The results show that circulating hsa-miR-122-5p and hsa-miR-4516 could be potential diagnostic biomarkers for osteoporosis in the future