Complex Formation of RNA Silencing Proteins in the Perinuclear Region of Neurospora crassa

In Neurospora, genes not paired during meiosis are targeted by meiotic silencing by unpaired DNA (MSUD). Here, our bimolecular fluorescence complementation (BiFC) study suggests that RNA-directed RNA polymerase, Dicer, Argonaute, and others form a silencing complex in the perinuclear region, with intimate interactions among the majority of them. We have also shown that SAD-2 is likely the anchor for this assembly.     

Regional Scale High Resolution δ18O Prediction in Precipitation Using MODIS EVI

The natural variation in stable water isotope ratio data, also known as water isoscape, is a spatiotemporal fingerprint and a powerful natural tracer that has been widely applied in disciplines as diverse as hydrology, paleoclimatology, ecology and forensic investigation. Although much effort has been devoted to developing a predictive water isoscape model, it remains a central challenge for scientists to generate high accuracy, fine scale spatiotemporal water isoscape prediction. Here we develop a novel approach of using the MODIS-EVI (the Moderate Resolution Imagining Spectroradiometer-Enhanced Vegetation Index), to predict δ¹⁸O in precipitation at the regional scale. Using a structural equation model, we show that the EVI and precipitated δ¹⁸O are highly correlated and thus the EVI is a good predictor of precipitated δ¹⁸O. We then test the predictability of our EVI-δ¹⁸O model and demonstrate that our approach can provide high accuracy with fine spatial (250×250 m) and temporal (16 days) scale δ¹⁸O predictions (annual and monthly predictabilities [r] are 0.96 and 0.80, respectively). We conclude the merging of the EVI and δ¹⁸O in precipitation can greatly extend the spatial and temporal data availability and thus enhance the applicability for both the EVI and water isoscape.     

Diversity, classification and function of the plant protein kinase superfamily

Eukaryotic protein kinases belong to a large superfamily with hundreds to thousands of copies and are components of essentially all cellular functions. The goals of this study are to classify protein kinases from 25 plant species and to assess their evolutionary history in conjunction with consideration of their molecular functions. The protein kinase superfamily has expanded in the flowering plant lineage, in part through recent duplications. As a result, the flowering plant protein kinase repertoire, or kinome, is in general significantly larger than other eukaryotes, ranging in size from 600 to 2500 members. This large variation in kinome size is mainly due to the expansion and contraction of a few families, particularly the receptor-like kinase/Pelle family. A number of protein kinases reside in highly conserved, low copy number families and often play broadly conserved regulatory roles in metabolism and cell division, although functions of plant homologues have often diverged from their metazoan counterparts. Members of expanded plant kinase families often have roles in plant-specific processes and some may have contributed to adaptive evolution. Nonetheless, non-adaptive explanations, such as kinase duplicate subfunctionalization and insufficient time for pseudogenization, may also contribute to the large number of seemingly functional protein kinases in plants.     

Soluble lectin-like oxidized low density lipoprotein receptor-1 in type 2 diabetes mellitus

The lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) can be proteolytically cleaved and released as soluble forms (sLOX-1). We have determined serums LOX-1 in type 2 diabetes and evaluated the effect of glucose and advanced glycation end products (AGEs) on sLOX-1 in vitro and in vivo. Endothelial cells were incubated with glucose or AGEs, and sLOX-1 in cell medium was measured. Serum sLOX-1 was measured in 219 diabetic patients and 187 controls by ELISA. The effect of lowering glucose and AGEs on sLOX-1 was determined in 38 poorly controlled diabetic patients after improvement in glycemic control. Incubation of endothelial cells with AGE-BSA led to a dose-dependent increase in sLOX-1, whereas the effect of glucose on sLOX-1 was less marked. Serum sLOX-1 was 9% higher in diabetic patients compared with controls (P<0.01). In the poorly controlled patients, serum sLOX-1 decreased by 12.5% after improvement in glycemic control (P<0.05). The magnitude of reduction in sLOX-1 correlated with the improvement in hemoglobin A1c and AGEs but not with the reduction in oxidized LDL. sLOX-1 level is increased in type 2 diabetes. Both glucose and AGEs are important determinants of LOX-1 expression, and lowering glucose and AGEs leads to a reduction in sLOX-1.     

Exercise therapy for prevention of falls in people with Parkinson's disease: A protocol for a randomised controlled trial and economic evaluation

Background

People with Parkinson's disease are twice as likely to be recurrent fallers compared to other older people. As these falls have devastating consequences, there is an urgent need to identify and test innovative interventions with the potential to reduce falls in people with Parkinson's disease. The main objective of this randomised controlled trial is to determine whether fall rates can be reduced in people with Parkinson's disease using exercise targeting three potentially remediable risk factors for falls (reduced balance, reduced leg muscle strength and freezing of gait). In addition we will establish the cost effectiveness of the exercise program from the health provider's perspective.

Methods/Design

230 community-dwelling participants with idiopathic Parkinson's disease will be recruited. Eligible participants will also have a history of falls or be identified as being at risk of falls on assessment. Participants will be randomly allocated to a usual-care control group or an intervention group which will undertake weight-bearing balance and strengthening exercises and use cueing strategies to address freezing of gait. The intervention group will choose between the home-based or support group-based mode of the program. Participants in both groups will receive standardized falls prevention advice. The primary outcome measure will be fall rates. Participants will record falls and medical interventions in a diary for the duration of the 6-month intervention period. Secondary measures include the Parkinson's Disease Falls Risk Score, maximal leg muscle strength, standing balance, the Short Physical Performance Battery, freezing of gait, health and well being, habitual physical activity and positive and negative affect schedule.

Discussion

No adequately powered studies have investigated exercise interventions aimed at reducing falls in people with Parkinson's disease. This trial will determine the effectiveness of the exercise intervention in reducing falls and its cost effectiveness. This pragmatic program, if found to be effective, has the potential to be implemented within existing community services.

Trial registration

The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12608000303347).     

Cytochemical investigation of genic male-sterility in Chinese cabbage

A genic male sterile Chinese cabbage, Brassica campestris L. ssp. chinensis Makino, was examined using cytological and cytochemical methods to characterize the process of pollen abortion in this plant. Thick sections of both fertile and sterile anthers at different developmental stages were stained using Toluidine Blue O, Periodic Acid-Schiff’s (PAS) reaction and Sudan Black B to detect cytochemical changes that may occur in the distribution of insoluble polysaccharide and lipid storage bodies. Pollen abortion in sterile anthers occurs at an early stage of microspore development. During early microspore development, reductions in the number of starch grains in the connective tissue of fertile anthers coincide with the accumulation of starch grains in cells of the anther wall. In the late microspore stage, a large vacuole forms in the microspore, and tapetal cells synthesize and accumulate lipid droplets. The cellular organization of tapetal cells in sterile anthers appears similar to that in fertile anthers, except for the absence of lipid droplets in cells of sterile anthers and diffusely labeled tapetal polysaccharides, suggesting defects in nutrient storage. Supported by National Natural Science Foundation of CHINA (30170060)     

Meiotic silencing by unpaired DNA.

The silencing of gene expression by segments of DNA present in excess of the normal number is called cosuppression in plants and quelling in fungi. We describe a related process, meiotic silencing by unpaired DNA (MSUD). DNA unpaired in meiosis causes silencing of all DNA homologous to it, including genes that are themselves paired. A semidominant Neurospora mutant, Sad-1, fails to perform MSUD. Sad-1 suppresses the sexual phenotypes of many ascus-dominant mutants. MSUD may provide insights into the function of genes necessary for meiosis, including genes for which ablation in vegetative life would be lethal. It may also contribute to reproductive isolation of species within the genus Neurospora. The wild-type allele, sad-1(+), encodes a putative RNA-directed RNA polymerase.