生物芯片研究现状及应用前景

生物芯片(Biochip)是以预先设计的方式将大量的生物讯息密码(寡核苷酸、cDNA、基因组DNA、蛋白质等)固定在玻片、硅片等固相载体上组成的密集分子阵列,可分为基因芯片、蛋白质芯片、芯片实验室三类。生物芯片技术的本质是生物信号的平行分析,它利用核酸分子杂交、蛋白分子亲和原理,通过荧光标记技术检测杂交或亲和与否,再经过计算机分析处理可迅速获得所需信息。在医学、分子生物学等领域,生物芯片技术以其高效、高信息量的优势,显现出巨大的应用价值和商业市场,其发展前景非常乐观。     

生物芯片技术难点和展望

简单回顾了生物芯片（Biochip）发展历史和基本定义,生物芯片是以预先设计的方式将大量的生物讯息密码（寡核苷酸、cDNA、基因组DNA、蛋白质等）固定在玻片、硅片等固相载体上组成的密集分子阵列．生物芯片技术本质是生物信号的平行分析,它利用核酸分子杂交、蛋白质分子亲和原理,通过荧光标记技术检测杂交或亲和与否,再经过计算机分析处理可迅速获得所需信息．本文主要概述了生物芯片技术的最新研究进展,并对生物芯片技术面临的挑战以及未来的发展方向作了讨论．     

肺癌的基因治疗

肺癌的发生、发展和演变与细胞原癌基因的激活和抑癌基因的失活有着 密切的关系，并已证实肺癌是一种多基因分子异常病。它的基因治疗是针对肺癌发生的分子生物学特点，通过基因转移技术，将新的外源目的基因引入肿瘤细胞或其他体细胞以纠正或补偿缺陷的基因，从而达到治疗疾病的目的。     

Antisense c-myb oligonucleotides inhibit intimal arterial smooth muscle cell accumulation in vivo.

Synthetic antisense oligonucleotides have been used to dissect gene function in vitro. Technical difficulties prevented the use of this approach for investigating the effect of gene products in vivo. Here we report the use of local delivery of antisense c-myb oligonucleotide to suppress intimal accumulation of rat carotid arterial smooth muscle cells. Our results suggest that antisense oligonucleotides can be used to define the in vivo biological role of specific macromolecules in the blood vessel wall and could potentially serve as a new class of therapeutic agents for cardiovascular disorders.     

A novel methodology for finding the regulation on gene expression data

DNA microarray technology is a high throughput and parallel technique for genomic investigation due to its advantages of simultaneously surveying features of large scales complex data in biology. This paper aims to find feature subset to build the classifier for gene expression data analysis. At first, K-means clustering algorithm was carried out on the dataset of yeast cell cycle. Based on rand calculation, a statistical method was used to pick out the data points (genes) for classifier design. Meanwhile, the principal component analysis was applied to help to construct the classifier. For the validation of classifier built and prediction of a target subset of genes, discriminant analysis in terms of partial least square regression and artificial neural network were also performed.     

转基因植物研究中目标蛋白鉴定方法研究进展

随着分子生物学和基因工程的迅速发展,基因转化技术的应用日益广泛.转基因研究的关键不仅要确定目的基因的正确导入,还必须证明目的基因正确表达,并形成有功能的蛋白.因此,转基因研究中对目标蛋白质的鉴定必不可少.本文对转基因研究中目标蛋白的鉴定方法概括总结,并对其发展趋势及研究热点予以展望.     

Transcriptional regulation of a metastasis suppressor gene by Tip60 and beta-catenin complexes

Defining the molecular strategies that integrate diverse signalling pathways in the expression of specific gene programmes that are critical in homeostasis and disease remains a central issue in biology. This is particularly pertinent in cancer biology because downregulation of tumour metastasis suppressor genes is a common occurrence, and the underlying molecular mechanisms are not well established. Here we report that the downregulation of a metastasis suppressor gene, KAI1, in prostate cancer cells involves the inhibitory actions of beta-catenin, along with a reptin chromatin remodelling complex. This inhibitory function of beta-catenin-reptin requires both increased beta-catenin expression and recruitment of histone deacetylase activity. The coordinated actions of beta-catenin-reptin components that mediate the repressive state serve to antagonize a Tip60 coactivator complex that is required for activation; the balance of these opposing complexes controls the expression of KAI1 and metastatic potential. The molecular mechanisms underlying the antagonistic regulation of beta-catenin-reptin and the Tip60 coactivator complexes for the metastasis suppressor gene, KAI1, are likely to be prototypic of a selective downregulation strategy for many genes, including a subset of NF-kappaB target genes.     

Immunodeficiency virus rev trans-activator modulates the expression of the viral regulatory genes

The pathogenic human retrovirus human immunodeficiency virus type 1 (HIV-1) encodes two trans-acting nuclear proteins, tat and rev, whose functional expression is essential for viral replication in vitro. The tat protein greatly enhances the expression of both structural and regulatory genes of HIV-1 (linked to the viral long-terminal-repeat promoter element), whereas the rev gene product (previously termed art or trs) has only been shown to be required for the synthesis of structural proteins. Here, we demonstrate that rev also moderates the expression of regulatory genes of HIV-1. It decreases the expression of messenger RNAs that encode the full-length form of the viral tat gene product or the rev protein itself, and induces the synthesis of a previously unreported, truncated tat protein. These actions of rev are mediated by a dramatic shift in the ratio of spliced to unspliced cytoplasmic HIV-1 mRNA. Therefore rev not only activates the synthesis of the viral structural proteins, but also modulates the level and quality of HIV-1 regulatory gene expression.     

Using the Acropora digitifera genome to understand coral responses to environmental change

Despite the enormous ecological and economic importance of coral reefs, the keystone organisms in their establishment, the scleractinian corals, increasingly face a range of anthropogenic challenges including ocean acidification and seawater temperature rise. To understand better the molecular mechanisms underlying coral biology, here we decoded the approximately 420-megabase genome of Acropora digitifera using next-generation sequencing technology. This genome contains approximately 23,700 gene models. Molecular phylogenetics indicate that the coral and the sea anemone Nematostella vectensis diverged approximately 500 million years ago, considerably earlier than the time over which modern corals are represented in the fossil record (～240 million years ago). Despite the long evolutionary history of the endosymbiosis, no evidence was found for horizontal transfer of genes from symbiont to host. However, unlike several other corals, Acropora seems to lack an enzyme essential for cysteine biosynthesis, implying dependency of this coral on its symbionts for this amino acid. Corals inhabit environments where they are frequently exposed to high levels of solar radiation, and analysis of the Acropora genome data indicates that the coral host can independently carry out de novo synthesis of mycosporine-like amino acids, which are potent ultraviolet-protective compounds. In addition, the coral innate immunity repertoire is notably more complex than that of the sea anemone, indicating that some of these genes may have roles in symbiosis or coloniality. A number of genes with putative roles in calcification were identified, and several of these are restricted to corals. The coral genome provides a platform for understanding the molecular basis of symbiosis and responses to environmental changes.     

Origin and evolution of new genes

Organisms have variable gcnome sizes and contain different numbers of genes. This difference demonstrates that new gene origination is a fundamental process in evolutionary biology. Though the study of the origination of new genes dated back more than half a century ago, it is not until the 1990s when the first young genejingwei was found that empirical investigation of the molecular mechanisms of origination of new genes became possible. In the recent years, several young genes were identified and the studies on these genes have greatly enriched the knowledge of this field. Yet more details in a general picture of new genes origination are to be clarified. We have developed a systematic approach to searching for young genes at the genomic level, in the hope to summarize a general pattern of the origination and evolution of new genes, such as the rate of new gene appearance, impact of new genes on their host genomes, etc.     

A test for intron function in the yeast actin gene

Many eukaryotic genes contain intervening sequences (IVS), but the rationale for their existence remains a mystery. Previous studies done in our laboratory demonstrated that the intron in a yeast tRNATyr gene, SUP6, does have a function. We used the same approach to determine the role of introns in nuclear genes encoding messenger RNAs. A single actin gene with one intron exists in Saccharomyces cerevisiae. The level of actin in yeast appears to be crucial to viability: either too much or too little actin inhibits growth. Therefore, small effects on synthesis of actin protein resulting from the removal of the actin gene intron would be expected to cause measurable changes in cell growth. In the present study, an intron-deleted actin gene was constructed in vitro and was used to replace the single resident actin gene in a haploid strain. Analysis of the cells carrying the intron-deleted actin gene shows that the intervening sequence is not essential for actin gene expression.     

The highly reduced genome of an enslaved algal nucleus

Chromophyte algae differ fundamentally from plants in possessing chloroplasts that contain chlorophyll c and that have a more complex bounding-membrane topology. Although chromophytes are known to be evolutionary chimaeras of a red alga and a non-photosynthetic host, which gave rise to their exceptional membrane complexity, their cell biology is poorly understood. Cryptomonads are the only chromophytes that still retain the enslaved red algal nucleus as a minute nucleomorph. Here we report complete sequences for all three nucleomorph chromosomes from the cryptomonad Guillardia theta. This tiny 551-kilobase eukaryotic genome is the most gene-dense known, with only 17 diminutive spliceosomal introns and 44 overlapping genes. Marked evolutionary compaction hundreds of millions of years ago eliminated nearly all the nucleomorph genes for metabolic functions, but left 30 for chloroplast-located proteins. To allow expression of these proteins, nucleomorphs retain hundreds of genetic-housekeeping genes. Nucleomorph DNA replication and periplastid protein synthesis require the import of many nuclear gene products across endoplasmic reticulum and periplastid membranes. The chromosomes have centromeres, but possibly only one loop domain, offering a means for studying eukaryotic chromosome replication, segregation and evolution.     

主要抗病候选基因在猪抗病育种中的研究进展

寻找与动物生理、生化、病理、连锁等方面有关的基因作为候选基因,分析候选基因的标记等位基因频率差异、标记等位基因的有无在抗性和易感性2个群体中的差异,从而间接地进行抗病育种,是一种有效的方法。本文对影响动物抗病力的天然抗性巨噬结合蛋白基因、干扰素基因、肠毒素型大肠杆菌K88受体基因、主要组织相容性复合体基因家族、MX抗病毒蛋白基因的国内外研究进行概述。     

植物耐旱基因工程研究进展

随着生物技术的发展 ,特别是基因工程技术的迅速发展 ,植物耐旱已从传统的植物生理研究转向分子方向 .目前植物耐旱研究的分子生物学方法主要是基因工程技术 ,包括植物耐旱相关基因的克隆 ,植物水胁迫代谢调节相关基因的分离、鉴定 ,以及通过植物遗传转化改变植物遗传性状———获得稳定的耐旱植株 ,进一步推广生产 .利用植物基因工程技术获得稳定耐旱植株 ,对于干旱地区的农业、生态环境、畜牧业以及城市绿地的改造来说可能又将引起一场新的绿色革命 .     

呼伦贝尔草地有害生物综合防治技术研究报告(Ⅰ)

2000年-2006年采用野外调查与田间小区试验相结合的方法，开展了呼伦贝尔草地有害生物综合防治技术的研究．通过几年的研究初步摸清了呼伦贝尔草地主要有害生物的种类及发生规律，提出了在当地目前草业生产中可行的综合防治技术．     

Molecular cloning of the whole biosynthetic pathway of a Streptomyces antibiotic and its expression in a heterologous host

The application of molecular cloning to antibiotic-producing microorganisms should lead to enhanced antibiotic productivity and to the biosynthesis of novel antibiotics by in vitro interspecific recombination. To allow such approaches, the genes for antibiotic synthesis must be isolated, analysed and perhaps modified. Certain Streptomyces species produce nearly two-thirds of the known natural antibiotics; the recent development of cloning systems in the genus makes it possible to isolate and analyse Streptomyces genes. However, antibiotics are metabolites which require sets of several enzymes for their synthesis and attempts to isolate the corresponding genes have so far yielded clones carrying either individual genes of the set, or only incomplete gene sets. We describe here the isolation of a large continuous segment of Streptomyces coelicolor DNA which apparently carries the complete genetic information required for synthesis of an antibiotic, actinorhodin , from simple primary metabolites. Not only can the cloned DNA 'complement' all available classes of actinorhodin non-producing mutants of S. coelicolor but, on introduction into a different host, Streptomyces parvulus , it directs the synthesis of the antibiotic. The tendency for the genes for antibiotic synthesis to be clustered together on the chromosomes of Streptomyces species and the availability of plasmid vectors which can carry stable inserts of DNA larger than 30 kilobase pairs (kb) and which can be introduced efficiently into Streptomyces protoplasts, suggest that the experiments described have general significance for this area of biotechnology.     

呼伦贝尔草地有害生物综合防治技术研究报告(Ⅱ)

2000-2006年采用野外调查与田间小区试验相结合的方法,开展了呼伦贝尔草地有害生物综合防治技术的研究.通过几年的研究初步摸清了呼伦贝尔草地主要有害生物的种类及发生规律,提出了在当地目前草业生产中可行的综合防治技术.     

植物组织培养过程中器官发生途径再生植株分子机制研究进展

 综述了植物组织离体培养过程器官发生途径所经历的3 个阶段的分子机制,包括已分化器官脱分化、根器官再生和芽器官再生。重点概述了禾谷类作物组织培养再生途径中的细胞遗传学机理。分析了当前植物再生性状分子基础研究存在的3 个主要问题,即具有稳定表现的高再生性能植物品种有限,再生性状相关主效基因发掘不足,已鉴定的再生相关基因功能不明显。提出应加强高再生性能植物品种选育,为发掘、控制植物离体组织培养再生关键基因提供丰富的基因资源,推动植物再生性状的分子机制研究。