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1.
Polyomavirus BK (BKV) infection is an important cause of renal allograft failure. Viral microRNAs are known to play a crucial role in viral replication. This study investigated the expression of BKV-encoded microRNAs (miR-B1) in patients with polyomavirus-associated nephropathy (PVAN) and their role in viral replication. Following BKV infection in renal proximal tubular cells, the 3p and 5p miR-B1 levels were significantly increased. Cells transfected with the vector containing the miR-B1 precursor (the miR-B1 vector) showed a significant increase in expression of 3p and 5p miR-B1 and decrease in luciferase activity of a reporter containing the 3p and 5p miR-B1 binding sites, compared to cells transfected with the miR-B1-mutated vector. Transfection of the miR-B1 expression vector or the 3p and 5p miR-B1 oligonucleotides inhibited expression of TAg. TAg-enhanced promoter activity and BKV replication were inhibited by miR-B1. In contrast, inhibition of miR-B1 expression by addition of miR-B1 antagomirs or silencing of Dicer upregulated the expression of TAg and VP1 proteins in BKV-infected cells. Importantly, patients with PVAN had significantly higher levels of 3p and 5p miR-B1 compared to renal transplant patients without PVAN. In conclusion, we demonstrated that (1) miR-B1 expression was upregulated during BKV infection and (2) miR-B1 suppressed TAg-mediated autoregulation of BKV replication. Use of miR-B1 can be evaluated as a potential treatment strategy against BKV infection.  相似文献   
2.
We introduce the computer tool “Know Your Samples” (KYSS) for assessment and visualisation of large scale proteomics datasets, obtained by mass spectrometry (MS) experiments. KYSS facilitates the evaluation of sample preparation protocols, LC peptide separation, and MS and MS/MS performance by monitoring the number of missed cleavages, precursor ion charge states, number of protein identifications and peptide mass error in experiments. KYSS generates several different protein profiles based on protein abundances, and allows for comparative analysis of multiple experiments. KYSS was adapted for blood plasma proteomics and provides concentrations of identified plasma proteins. We demonstrate the utility of the KYSS tool for MS based proteome analysis of blood plasma and for assessment of hydrogel particles for depletion of abundant proteins in plasma. The KYSS software is open source and is freely available at http://kyssproject.github.io/.  相似文献   
3.
It is currently a routine practice to require a measurement of a housekeeping reference, including actin, glyceraldehyde-3-phosphate dehydrogenase, β-tubulin, among others, in Western blots, as it is the rule in RNA blots. Reversible Ponceau staining has been applied successfully to check equal loading of gels. Here we test a new technique, with the Stain-Free gels from Bio-Rad, against both Ponceau staining and housekeeping protein immunodetection under different conditions. Our results show that Stain-Free gels outperform Ponceau staining and that both are more consistent than housekeeping proteins as a loading control.  相似文献   
4.
1. Population dynamics and interactions that vary over a species' range are of particular importance in the context of latitudinal clines in biological diversity. Winter moth (Operophtera brumata) and autumnal moth (Epirrita autumnata) are two species of eruptive geometrids that vary widely in outbreak tendency over their range, which generally increases from south to north and with elevation. 2. The predation pressure on geometrid larvae and pupae over an elevational gradient was tested. The effects of background larval density and bird occupancy of monitoring nest boxes on predation rates were also tested. Predation on larvae was tested through exclusion treatments at 20 replicate stations over four elevations at one site, while pupae were set out to measure predation at two elevations at three sites. 3. Larval densities were reduced by bird predation at three lower elevations, but not at the highest elevation, and predation rates were 1.9 times higher at the lowest elevation than at the highest elevation. The rate of predation on larvae was not related to background larval density or nest box occupancy, although there were more eggs and chicks at the lowest elevation. There were no consistent differences in predation on pupae by elevation. 4. These results suggest that elevational variation in avian predation pressure on larvae may help to drive elevational differences in outbreak tendency, and that birds may play a more important role in geometrid population dynamics than the focus on invertebrate and soil predators of previous work would suggest.  相似文献   
5.
疾病资源库在转化医学发展中发挥着重要作用,收集人类遗传资源和疾病相关资源信息,建设疾病资源库越来越受到重视。首都医科大学附属北京佑安医院在建设乙型肝炎和艾滋病疾病资源库的过程中,总结疾病资源库建设经验,为中国疾病资源库建设的标准化提供参考。  相似文献   
6.
A key question in ecology is under which conditions ecosystem structure tends to be controlled by resource availability vs. consumer pressure. Several hypotheses derived from theory, experiments and observational field studies have been advanced, yet a unified explanation remains elusive. Here, we identify common predictors of trophic control in a synthetic analysis of 52 observational field studies conducted within marine ecosystems across the Northern Hemisphere and published between 1951 and 2014. Spatial regression analysis of 45 candidate variables revealed temperature to be the dominant predictor, with unimodal effects on trophic control operating both directly (r2 = 0.32; P < 0.0001) and indirectly through influences on turnover rate and quality of primary production, biodiversity and omnivory. These findings indicate that temperature is an overarching determinant of the trophic dynamics of marine ecosystems, and that variation in ocean temperature will affect the trophic structure of marine ecosystems through both direct and indirect mechanisms.  相似文献   
7.
棉田非靶标害虫发生丰度与气象因子的关联性分析   总被引:1,自引:0,他引:1       下载免费PDF全文
【背景】近年来,全球气候条件不断变化,其对农田生态系统和病虫草害发生的影响较大。【方法】于2009~2013年在河南安阳田间小区系统调查了转基因棉田和非转基因棉田主要害虫种群丰度,结合5年间本地气象因素,分段分析了影响棉田主要害虫发生的关键气象因子及其关键影响时期。【结果】不同害虫发生危害的关键气象因子及其关键影响时期不同,且不同害虫种群丰度与气象因子及其影响时期有不同的相关性。影响棉蚜的关键性气象因子是1~8月的平均气温,与相对湿度和降雨量相关性较低;影响棉叶蝉的关键气象因子是1~4月的降雨量,其次是1~8月的相对湿度,而平均气温与其相关性很低;5~8月降雨量对烟粉虱有一定的抑制作用,平均气温和相对湿度对其无显著影响;影响棉蓟马的关键气象因子是平均气温,其次是5~8月相对湿度,降雨量与棉蓟马丰度相关性较低;平均气温、相对湿度和降雨量与盲蝽种群丰度的相关性很低,其发生危害可能是多种气象因子协同作用的结果。【结论与意义】本研究结果可为气候变化条件下棉田主要害虫的预测预报和防御提供理论依据。  相似文献   
8.
  1. Top‐down population regulation can influence the success of biological control agents when they are released into the field. Entomopathogenic nematodes (EPNs) are used commonly in biological control programmes, but their efficacy suffers from poor persistence. Although abiotic soil conditions have been shown to reduce EPN persistence, consumption of infected insects by scavengers and of infective juvenile (IJ) nematodes by predators may also regulate these populations. In the present study, the effects of different soil arthropods on EPNs in laboratory conditions were measured. It was hypothesised that arthropods commonly found in soil communities where EPNs are applied would consume cadavers of insects parasitised by the nematodes and the IJs themselves.
  2. Some species of scavengers consume EPN‐infected insects. Crickets (Gryllus bimaculatus De Geer), American cockroaches [Periplaneta Americana (Linnaeus)], ants [Tetramorium chefketi Forel and Pheidole pallidula (Nylander)], earwigs (Labidura riparia Pallas), mites (Sancassania polyphyllae Zachvatkin), and springtails (Sinella curviseta Brook and Folsomia candida Willem) have different responses to nematode‐killed insects. Results suggested that ants (T. chefketi), cockroaches, mites, and earwigs fed on Steinernema‐killed insects whereas neither crickets nor springtails consumed them.
  3. In the second part of the study, experiments were conducted to determine whether mites and springtails consumed IJ EPNs. Results showed that S. polyphyllae mites do not consume infective juveniles in soil, whereas both springtail species consumed significant numbers of the IJs.
  4. Top‐down regulatory processes can be a limiting factor for EPN populations under laboratory conditions. Both host cadavers and IJs are consumed (albeit by different arthropods), so these results may help explain the difficulties associated with the persistence of EPN application to soil.
  相似文献   
9.
Various molecular and cellular pathways are active in eukaryotes to control the quality and integrity of mitochondria. These pathways are involved in keeping a ‘healthy’ population of this essential organelle during the lifetime of the organism. Quality control (QC) systems counteract processes that lead to organellar dysfunction manifesting as degenerative diseases and ageing. We discuss disease- and ageing-related pathways involved in mitochondrial QC: mtDNA repair and reorganization, regeneration of oxidized amino acids, refolding and degradation of severely damaged proteins, degradation of whole mitochondria by mitophagy and finally programmed cell death. The control of the integrity of mtDNA and regulation of its expression is essential to remodel single proteins as well as mitochondrial complexes that determine mitochondrial functions. The redundancy of components, such as proteases, and the hierarchies of the QC raise questions about crosstalk between systems and their precise regulation. The understanding of the underlying mechanisms on the genomic, proteomic, organellar and cellular levels holds the key for the development of interventions for mitochondrial dysfunctions, degenerative processes, ageing and age-related diseases resulting from impairments of mitochondria.  相似文献   
10.
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