Vision and development in Trichoderma atroviride

Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to conidiate upon exposure to light. In total darkness, T. atroviride grows indefinitely as a mycelium provided that nutrients are not limiting. However, nutrient deprivation and light trigger the conidiation process. A pulse of blue light given to a radially growing colony induc…     

Serological evidence for exposure to avian influenza viruses within poultry workers in southern China

The risk of infection with avian influenza viruses for poultry workers is relatively unknown in China, and study results are often biased by the notification of only the severe human cases. Protein microarray was used to detect binding antibodies to 13 different haemagglutinin (HA1‐part) antigens of avian influenza A(H5N1), A(H7N7), A(H7N9) and A(H9N2) viruses, in serum samples from poultry workers and healthy blood donors collected in the course of 3 years in Guangdong Province, China. Significantly higher antibody titre levels were detected in poultry workers when compared to blood donors for the most recent H5 and H9 strains tested. These differences were most pronounced in younger age groups for antigens from older strains, but were observed in all age groups for the recent H5 and H9 antigens. For the H7 strains tested, only poultry workers from two retail live poultry markets had significantly higher antibody titres compared to blood donors.     

SSH与cDNA芯片技术的联合及其在植物基因差异表达研究中的应用

抑制消减杂交技术(SSH)与cDNA芯片技术是新近发展起来的研究差异表达基因的两种非常有效的方法。近年来,将SSH和cDNA芯片技术结合使用,为分析组织细胞的已知基因表达差异提供了新的手段,也为克隆和鉴定新基因开辟了新的道路,是目前寻找差异表达基因的适用方法。鉴于此,对SSH和cDNA芯片技术的基本原理、两种方法结合使用的操作流程、克隆差异表达新基因的特点,以及在植物基因差异表达方面的应用进行了概述。     

Culex pipiens pallens: identification of genes differentially expressed in deltamethrin-resistant and -susceptible strains

Insecticide-resistance is a major obstacle to controlling insect vectors of microorganisms that cause human diseases. Identification of genes associated with resistance to insecticides has been a valuable tool for understanding mechanisms underlying resistance to commonly used insecticides such as deltamethrin. To identify such genes, we used suppression subtractive hybridization to obtain 809 differentially expressed clones in deltamethrin resistant versus susceptible laboratory strains of Culex pipiens pallens. Using cDNA microarrays and reverse Northern blots, a subset of 16 clones was confirmed to have greater than 3-fold difference in expression levels. Within this subset, we identified 2 clones uniquely expressed in the deltamethrin-resistant strain, eight clones exhibiting higher expression in the resistant strain and six in the susceptible strain. Of these 16 clones, 13 clones have sequence homology to known genes, such as ribosomal RNA, ribosome proteins, trypsin, and chymotrypsin-like proteins. Our data suggests resistance to deltamethrin may be a polygenic phenotype.     

兰花5种病毒可视化基因芯片检测方法建立

为建立运用可视基因芯片技术快速、准确检测兰花病毒的方法,选择黄瓜花叶病毒、齿舌兰环斑病毒、建兰花叶病毒编码外壳蛋白(coat protein,CP)基因、辣椒褪绿病毒编码核衣壳蛋白N基因、落葵皱纹花叶病毒编码CI蛋白基因为目标基因,设计引物和探针(5'标记一段poly T)。利用多重RT-PCR方法进行病毒核酸扩增,将扩增产物与固定于芯片的特异性探针杂交,经清洗、可视化显色后进行结果分析。在优化的检测条件下,本研究筛选出2组多重引物组合Cm(F2-R2a)、Ba(F1-R1);Or(F1-R1)、Cy(F2-R2)和Ca(F1-R1),5条特异性探针。所建立的可视基因芯片具有较好的特异性和重复性,可检测出病毒阳性质粒的量为不低于10~3拷贝·μL~(-1)。     

Advances in molecular phytodiagnostics – new solutions for old problems

In the last decade, developments in molecular (nucleic acid-based) diagnostic methods have made significant improvements in the detection of plant pathogens. By using methods such as the polymerase chain reaction (PCR), the range of targets that can now be reliably diagnosed has grown to the extent that there are now extremely few, known pathogens that cannot be identified accurately by using laboratory-based diagnostics. However, while the detection of pathogens in individual, infected samples is becoming simpler, there are still many scenarios that present a major challenge to diagnosticians and plant pathologists. Amongst these are the detection of pathogens in soil or viruses in their vectors, high throughput testing and the development of generic methods, that allow samples to be simultaneously screened for large numbers of pathogens. Another major challenge is to develop robust technologies that avoid the reliance on well-equipped central laboratories and making reliable diagnostics available to pathologists in the field or in less-developed countries. In recent years, much of the research carried out on phytodiagnostics has focussed in these areas and as a result many novel, routine diagnostic tests are becoming available. This has been possible due to the introduction of new molecular technologies such real-time PCR and microarrays. These advances have been complemented by the development of new nucleic acid extraction methods, increased automation, reliable internal controls, assay multiplexing and generic amplification methods. With developments in new hardware, field-portable real-time PCR is now also a reality and offers the prospect of ultra-rapid, on-site molecular diagnostics for the first time. In this paper, the development and implementation of new diagnostic methods based upon novel molecular techniques is presented, with specific examples given to demonstrate how these new methods can be used to overcome some long-standing problems. An erratum to this article can be found at     

Regulation of cytochrome P450 expression in Drosophila: Genomic insights

Genomic tools such as the availability of the Drosophila genome sequence, the relative ease of stable transformation, and DNA microarrays have made the fruit fly a powerful model in insecticide toxicology research. We have used transgenic promoter-GFP constructs to document the detailed pattern of induced Cyp6a2 gene expression in larval and adult Drosophila tissues. We also compared various insecticides and xenobiotics for their ability to induce this cytochrome P450 gene, and show that the pattern of Cyp6a2 inducibility is comparable to that of vertebrate CYP2B genes, and different from that of vertebrate CYP1A genes, suggesting a degree of evolutionary conservation for the “phenobarbital-type” induction mechanism. Our results are compared to the increasingly diverse reports on P450 induction that can be gleaned from whole genome or from “detox” microarray experiments in Drosophila. These suggest that only a third of the genomic repertoire of CYP genes is inducible by xenobiotics, and that there are distinct subsets of inducers/induced genes, suggesting multiple xenobiotic transduction mechanisms. A relationship between induction and resistance is not supported by expression data from the literature. The relative abundance of expression data now available is in contrast to the paucity of studies on functional expression of P450 enzymes, and this remains a challenge for our understanding of the toxicokinetic aspects of insecticide action.     

用于诊断4种猪病毒病的寡核苷酸芯片的研制

制备可同时检测引起集约化养猪业常见4种传染病，病毒（猪流感病毒、口蹄疫病毒、猪伪狂犬病毒、猪蓝耳）的寡核苷酸芯片。根据4种猪疫病病毒特异性基因的保守区域设计合成了60mer寡核苷酸探针，制备寡核苷酸芯片。采用不对称PCR和间接荧光标记技术进行单链DNA扩增和荧光标记，标记样品与寡核苷酸芯片杂交后，进行芯片清洗、扫描及结果分析。杂交结果显示，4种病毒的寡核苷酸检测探针均特异地与相应的标记样品杂交，芯片上呈现较强的阳性杂交信号，而除阳性质控探针外，阴性对照和空白对照均检测不到荧光信号。证明寡核苷酸芯片适用于快速、准确、高通量地诊断影响集约化养猪业的多种猪疫痛病毒。