Microarray analysis of differentially expressed genes engaged in fruit development between table and wine grape

Microarray analysis of genes can provide individual gene-expression profiles and new insights for elucidating biological mechanisms responsible for fruit development. To obtain an overall view on expression profiles of metabolism-related genes involved in fruit development of table and wine grapes, a microarray system comprising 15,403 ESTs was used to compare the expressed genes. The expression patterns from the microarray analysis were validated with quantitative real-time polymerase chain reaction analysis of 18 selected genes of interest. During the entire fruit development stage, 2,493 genes exhibited at least 2.0-fold differences in expression levels with 1,244 genes being up-regulated and 1,249 being down-regulated. Following gene ontology analysis, only 929 differentially expressed (including 403 up-regulated and 526 down-regulated) genes were annotated in table and wine grapes. These differentially expressed genes were found to be mainly involved in carbohydrate metabolism, biosynthesis of secondary metabolites as well as energy, lipid and amino acid metabolism via KEGG. Our results provide new insights into the molecular mechanisms and expression profiles of genes in the fruit development stage of table and wine grapes.     

利用基因芯片技术研究两品种鸡脂肪组织差异表达基因

应用包含9024条鸡cDNA的表达谱芯片,对从两品种鸡脂肪组织抽提及纯化的mRNA进行芯片杂交,并对基因表达谱进行分析,旨在筛选高脂肉鸡和白耳蛋鸡脂肪组织差异表达的基因,探讨造成两品种体脂性状差异的分子生物学机理。结果按差异显著阳性标准分析,共筛选出差异表达基因67条,主要涉及脂类代谢、能量代谢、细胞骨架构成、转录和剪接因子以及蛋白质合成与分解等相关基因,此外,还筛选出一些尚未在GenBank上登陆的序列,推测可能是未知的新基因,它们在鸡脂类代谢的过程所起到的作用还需进一步实验证明。     

Candidate genes involved in tanshinone biosynthesis in hairy roots of <Emphasis Type="Italic">Salvia miltiorrhiza</Emphasis> revealed by cDNA microarray

Salvia miltiorrhiza is a valuable Chinese herb (Danshen) that is widely used in traditional Chinese medicine. Diterpene quinones, known as tanshinones, are the main bioactive components of S. miltiorrhiza; however, there is only limited information regarding the molecular mechanisms underlying secondary metabolism in this plant. We used cDNA microarray analysis to identify changes in the gene expression profile at different stages of hairy root development in S. miltiorrhiza. A total of 203 genes were singled out from 4,354 cDNA clones on the microarray, and 114 unique differentially expressed cDNA clones were identified: six genes differentially expressed in 45-day hairy root compared with 30-day hairy root; 96 genes differentially expressed in 60-day hairy root compared with 30-day hairy root; and 12 genes unstably expressed at different stages. Among the 96 genes differentially expressed in 60-day hairy root compared with 30-day hairy root, a total of 57 genes were up-regulated, and 26 genes represent 29 metabolism-related enzymes. Copalyl diphosphate synthase, which catalyzes the conversion of the universal diterpenoid precursor (E,E,E)-geranylgeranyl diphosphate to copalyl diphosphate, was up-regulated 6.63 fold, and another six genes involved in tanshinone biosynthesis and eight candidate P450 genes were also differentially expressed. These data provide new insights for further identification of the enzymes involved in tanshinone biosynthesis.     

Tuber on a chip: differential gene expression during potato tuber development

Potato tuber development has proven to be a valuable model system for studying underground sink organ formation. Research on this topic has led to the identification of many genes involved in this complex process and has aided in the unravelling of the mechanisms underlying starch synthesis. However, less attention has been paid to the biochemical pathways of other important metabolites or to the changing metabolic fluxes occurring during potato tuber development. In this paper, we describe the construction of a potato complementary DNA (cDNA) microarray specifically designed for genes involved in processes related to tuber development and tuber quality traits. We present expression profiles of 1315 cDNAs during tuber development where the predominant profiles were strong up- and down-regulation. Gene expression profiles showing transient increases or decreases were less abundantly represented and followed more moderate changes, mainly during tuber initiation. In addition to the confirmation of gene expression patterns during tuber development, many novel differentially expressed genes were identified and are considered as candidate genes for direct involvement in potato tuber development. A detailed analysis of starch metabolism genes provided a unique overview of expression changes during tuber development. Characteristic expression profiles were often clearly different between gene family members. A link between differential gene expression during tuber development and potato tissue specificity is described. This dataset provides a firm basis for the identification of key regulatory genes in a number of metabolic pathways that may provide researchers with new tools to achieve breeding goals for use in industrial applications.     

Cloning of genes differentially expressed during the initial stage of fruit development in melon (Cucumis melo cv. Reticulatus)

We have cloned genes involved in the initial stage of fruit development in the melon by suppression subtractive hybridization. A cDNA library of unfertilized ovules was subtracted from that of fruit 9 days after pollination (DAP); 10 of the 40 selected cDNA clones were identified by reverse Northern analysis as genes differentially expressed in fruit at 9 DAP. Seven of the ten genes were homologous to genes of known function; two were related to genes with unknown functions, and one was novel. With the exception of cucumisin, none of the cDNAs had been previously identified in melon. According to Northern analyses, six of the genes were expressed at high levels early in fruit development. Expression of cucumisin, Cmf-25, Cmf-30, and Cmf-124 was highest at 9 DAP, implying that these genes are involved in the initial stage of fruit development. Cmf-30, a seed nucellus-specific gene, was also expressed early in seed development. The other genes were expressed at a moderate level throughout fruit development, with the highest expression occurring in fruit at 9 and 18 DAP. In conclusion, nine new genes involved in early fruit development in melon were cloned, and their temporal and spatial expression patterns indicate that they are preferentially expressed during the active growing stage of fruit.     

Infection with street strain rabies virus induces modulation of the microRNA profile of the mouse brain

ABSTRACT: BACKGROUND: Rabies virus (RABV) causes a fatal infection of the central nervous systems (CNS) of warm-blooded animals. Once the clinical symptoms develop, rabies is almost invariably fatal. The mechanism of RABV pathogenesis remains poorly understood. Recent studies have shown that microRNA (miRNA) plays an important role in the pathogenesis of viral infections. Our recent findings have revealed that infection with laboratory-fixed rabies virus strain can induce modulation of the microRNA profile of mouse brains. However, no previous report has evaluated the miRNA expression profile of mouse brains infected with RABV street strain. RESULTS: The results of microarray analysis show that miRNA expression becomes modulated in the brains of mice infected with street RABV. Quantitative real-time PCR assay of the differentially expressed miRNAs confirmed the results of microarray assay. Functional analysis showed the differentially expressed miRNAs to be involved in many immune-related signaling pathways, such as the Jak-STAT signaling pathway, the MAPK signaling pathway, cytokine-cytokine receptor interactions, and Fc gamma R-mediated phagocytosis. The predicted expression levels of the target genes of these modulated miRNAs were found to be correlated with gene expression as measured by DNA microarray and qRT-PCR. CONCLUSION: RABV causes significant changes in the miRNA expression profiles of infected mouse brains. Predicted target genes of the differentially expression miRNAs are associated with host immune response, which may provide important information for investigation of RABV pathogenesis and therapeutic method.     

利用基因芯片技术筛选秦川牛公牛与阉牛肌肉组织差异表达基因

为了筛选秦川牛公牛和阉牛肌肉组织差异表达的基因,探讨二者肉质差异的分子生物学机理,文章利用Affymetrix公司生产的牛基因组芯片技术,分别检测了3头36月龄秦川牛公牛与阉牛背最长肌肌肉组织的mRNA表达水平变化;运用Significance Analysis of Microarrays(SAM)法对秦川牛公牛和阉牛基因表达谱进行了差异分析;并通过分子注释系统平台(MAS2.0)对差异表达基因进行了功能富集类分析和调控通路分析;最后应用实时定量PCR技术对部分差异表达基因进行了验证。基因表达谱分析结果显示,在36月龄秦川牛的肌肉组织中,共检测到约11000个探针,代表大约10000个基因。共筛选出差异表达基因143条,主要涉及胶原纤维的组织和合成、细胞粘附、细胞生长调控、泛素介导的蛋白分解代谢和横纹肌收缩等生物学过程;在分子注释系统数据库中注释到的显著调控通路为细胞外基质受体反应、细胞通讯、焦点粘连和紧密连接等;所验证的差异表达基因的荧光定量PCR结果与芯片结果基本一致。结合已有的文献报道,文章初步认为ECM受体反应、细胞通讯、焦点粘连、紧密接头等调控通路及COL3A1、COL1A1、COL1A2、SPP1、FBN1、MMP2、ECM1、MYH3、MYH8、S100A4、ASPN、CFD等基因可能是参与调控秦川牛阉割前后肉质性状差异的重要调控通路和基因。此外,还筛选出一些尚未在GenBank上登陆的序列,推测可能是未知的新基因,它们在牛肉质代谢过程中的作用还需进一步的研究证明。     

Analysis of Gene Expression Following Sciatic Nerve Crush and Spinal Cord Hemisection in the Mouse by Microarray Expression Profiling

1. The responses of periphery (PNS) and central nervous systems (CNS) towards nerve injury are different: while injured mammalian periphery nerons can successfully undergo regeneration, axons in the central nervous system are usually not able to regenerate.2. In the present study, the genes which were differentially expressed in the PNS and CNS following nerve injury were identified and compared by microarray profiling techniques.3. Sciatic nerve crush and hemisection of the spinal cord of adult mice were used as the models for nerve injury in PNS and CNS respectively.4. It was found that of all the genes examined, 14% (80/588) showed changes in expression following either PNS or CNS injury, and only 3% (18/588) showed changes in both types of injuries.5. Among all the differentially expressed genes, only 8% (6/80) exhibited similar changes in gene expression (either up- or down-regulation) following injury in both PNS and CNS nerve injuries.6. Our results indicated that microarray expression profiling is an efficient and useful method to identify genes that are involved in the regeneration process following nerve injuries, and several genes which are differentially expressed in the PNS and/or CNS following nerve injuries were identified in the present study.