Plant genome databases: from references to inference tools

Plant genome databases play an important role in the archiving and dissemination of data arising from the international genome projects. Recent developments in bioinformatics, such as new software tools, programming languages and standards, have produced better access across the Internet to the data held within them.An increasing emphasis is placed on data analysis and indeed many resources now provide tools allied to the databases, to aid in the analysis and interpretation of the data. However, a considerable wealth of information lies untapped by considering the databases as single entities and will only be exploited by linking them with a wide range of data sources. Data from research programs such as comparative mapping and germplasm studies may be used as tools, to gain additional knowledge but without additional experimentation. To date, the current plant genome databases are not yet linked comprehensively with each other or with these additional resources, although they are clearly moving toward this. Here, the current wealth of public plant genome databases is reviewed, together with an overview of initiatives underway to bind them to form a single plant genome infrastructure.     

New approaches towards integrated proteomic databases and depositories

Since the publication of the human genome, two key points have emerged. First, it is still not certain which regions of the genome code for proteins. Second, the number of discrete protein-coding genes is far fewer than the number of different proteins. Proteomics has the potential to address some of these postgenomic issues if the obstacles that we face can be overcome in our efforts to combine proteomic and genomic data. There are many challenges associated with high-throughput and high-output proteomic technologies. Consequently, for proteomics to continue at its current growth rate, new approaches must be developed to ease data management and data mining. Initiatives have been launched to develop standard data formats for exchanging mass spectrometry proteomic data, including the Proteomics Standards Initiative formed by the Human Proteome Organization. Databases such as SwissProt and Uniprot are publicly available repositories for protein sequences annotated for function, subcellular location and known potential post-translational modifications. The availability of bioinformatics solutions is crucial for proteomics technologies to fulfil their promise of adding further definition to the functional output of the human genome. The aim of the Oxford Genome Anatomy Project is to provide a framework for integrating molecular, cellular, phenotypic and clinical information with experimental genetic and proteomics data. This perspective also discusses models to make the Oxford Genome Anatomy Project accessible and beneficial for academic and commercial research and development.     

EBI databases and services

The EMBL Outstation-European Bioinformatics Institute (EBI) is a center for research and services in bioinformatics. It serves researchers in molecular biology, genetics, medicine, and agriculture from academia, and the agricultural, biotechnology, chemical, and pharmaceutical industries. The Institute manages and makes available databases of biological data including nucleic acid, protein sequences, and macromolecular structures. It provides to this community bioinformatics services relevant to molecular biology free of charge over the Internet. Some of these databases and services are described in this review. For more information, visit the EBI Web server at http://www.ebi.ac.uk/.     

Farm animal milk proteomics

Milk is one of the most important nutrients for humans during lifetime. Farm animal milk in all its products like cheese and other fermentation and transformation products is a widespread nutrient for the entire life of humans. Proteins are key molecules of the milk functional component repertoire and their investigation represents a major challenge. Proteins in milk, such as caseins, contribute to the formation of micelles that are different from species to species in dimension and casein-type composition; they are an integral part of the MFGM (Milk Fat Globule Membrane) that has being exhaustively studied in recent years. Milk proteins can act as enzymes or have an antimicrobial activity; they could act as hormones and, last but not least, they have a latent physiological activity encoded in their primary structure that turns active when the protein is cleaved by fermentation or digestion processes. In this review we report the last progress in proteomics, peptidomics and bioinformatics. These new approaches allow us to better characterize the milk proteome of farm animal species, to highlight specific PTMs, the peptidomic profile and even to predict the potential nutraceutical properties of the analyzed proteins.     

Arabidopsis genome analysis as exemplified by analysis of chromosome 4

During the last decade the small cruciferous plant Arabidopsis thaliana has become a model organism for flowering plants. Sequencing and analysis of the Arabidopsis genome is nearing completion. Beside an overview on methods and strategies for Arabidopsis genome analysis, a summary of the results from the first analysis is presented.This includes an overview on chromosomal organisation and topological features as well as a first comparison with other genomes.     

微生物基因组研究进展

本综述了微生物全基因组测序的基本方法,数据收集和组装,序列缺口的填充、全基因组序列注释。同时对微生物基因组的研究现状和重大意义也作了简单概述。     

Analysis and comparison of metabolic pathway databases

Enormous amounts of data result from genome sequencing projects and new experimental methods. Within this tremendous amount of genomic data 30-40 per cent of the genes being identified in an organism remain unknown in terms of their biological function. As a consequence of this lack of information the overall schema of all the biological functions occurring in a specific organism cannot be properly represented. To understand the functional properties of the genomic data more experimental data must be collected. A pathway database is an effort to handle the current knowledge of biochemical pathways and in addition can be used for interpretation of sequence data. Some of the existing pathway databases can be interpreted as detailed functional annotations of genomes because they are tightly integrated with genomic information. However, experimental data are often lacking in these databases. This paper summarises a list of pathway databases and some of their corresponding biological databases, and also focuses on information about the content and the structure of these databases, the organisation of the data and the reliability of stored information from a biological point of view. Moreover, information about the representation of the pathway data and tools to work with the data are given. Advantages and disadvantages of the analysed databases are pointed out, and an overview to biological scientists on how to use these pathway databases is given.     

Shopping in the genome market with EnsMart

Life scientists who work with the supermarket of genome data will find the EnsMart database and software package offers a valuable door to a wealth of genes and genome features. Not only available to lab biologists on the web, this popular multi-organism genome database can be installed and used on your own Unix computer with relative ease. It offers a flexible, fast and practical data-mining framework for computer-savvy biologists and bioinformaticians.     

Discovering and detecting transposable elements in genome sequences

The contribution of transposable elements (TEs) to genome structure and evolution as well as their impact on genome sequencing, assembly, annotation and alignment has generated increasing interest in developing new methods for their computational analysis. Here we review the diversity of innovative approaches to identify and annotate TEs in the post-genomic era, covering both the discovery of new TE families and the detection of individual TE copies in genome sequences. These approaches span a broad spectrum in computational biology including de novo, homology-based, structure-based and comparative genomic methods. We conclude that the integration and visualization of multiple approaches and the development of new conceptual representations for TE annotation will further advance the computational analysis of this dynamic component of the genome.     

Comparative mapping in farm animals.

This paper summarises the current status of comparative mapping in farm animals. For most of the major farm animal species, a wide range of genomic tools are now available to create high-resolution genetic and physical maps of the genome. For many farm animals, the use of radiation hybrid panels and sequence data from expressed sequence tag (EST) projects has accelerated the development of high-resolution comparative maps, with human--the model species for farm animals. These tools and comparative maps are being used to map and identify the genes at the loci for simple and complex traits. The development of detailed physical maps in farm animals based on radiation hybrid panels and bacterial artificial chromosome (BAC) contigs provides a direct link between the 'information-poor' maps of farm animals and the 'information-rich' genomes of human and other model organisms.     

Computational analysis of human genome polymorphism

While genome-era technologies focused on complete genome sequencing in various organisms, post-genome technologies aim at the understanding of the mechanisms of genetic information processing and elucidation of within-species variation. Single nucleotide polymorphisms (SNPs) are the most common source of genome variation in the human population. Nonsynonymous SNPs that occur in coding gene regions and result in amino acid substitutions are of particular interest. It is thought that such SNPs are responsible for phenotypic variation, quantitative traits, and the etiology of common diseases. PolyPhen is a computational tool for the prediction of putatively functional nonsynonymous SNPs by combining information of various types. The application areas of PolyPhen and similar methods include the genetics of complex diseases and congenital defects, the identification of functional mutations in model organisms, and evolutionary genetics.     

Comparative assessment of human and farm animal faecal microbiota using real-time quantitative PCR

Pollution of the environment by human and animal faecal pollution affects the safety of shellfish, drinking water and recreational beaches. To pinpoint the origin of contaminations, it is essential to define the differences between human microbiota and that of farm animals. A strategy based on real-time quantitative PCR (qPCR) assays was therefore developed and applied to compare the composition of intestinal microbiota of these two groups. Primers were designed to quantify the 16S rRNA gene from dominant and subdominant bacterial groups. TaqMan^® probes were defined for the qPCR technique used for dominant microbiota. Human faecal microbiota was compared with that of farm animals using faecal samples collected from rabbits, goats, horses, pigs, sheep and cows. Three dominant bacterial groups ( Bacteroides/Prevotella, Clostridium coccoides and Bifidobacterium ) of the human microbiota showed differential population levels in animal species. The Clostridium leptum group showed the lowest differences among human and farm animal species. Human subdominant bacterial groups were highly variable in animal species. Partial least squares regression indicated that the human microbiota could be distinguished from all farm animals studied. This culture-independent comparative assessment of the faecal microbiota between humans and farm animals will prove useful in identifying biomarkers of human and animal faecal contaminations that can be applied to microbial source tracking methods.     

New selenoproteins identified in silico from the genome of Anopheles gambiae

Selenoprotein is biosynthesized by the incorporation of selenocysteine into proteins, where the TGA codon in the open reading frame does not act as a stop signal but is translated into selenocysteine. The dual functions of TGA result in mis-annotation or lack of selenoproteins in the sequenced genomes of many species. Available computational tools fail to correctly predict selenoproteins. Thus, we developed a new method to identify selenoproteins from the genome of Anopheles gambiae computationally.Based on released genomic information, several programs were edited with PERL language to identify selenocysteine insertion sequence (SECIS) element, the coding potential of TGA codons, and cysteine-containing homologs of selenoprotein genes. Our results showed that 11365 genes were terminated with TGA codons, 918 of which contained SECIS elements. Similarity search revealed that 58genes contained Sec/Cys pairs and similar flanking regions around in-frame TGA codons. Finally, 7genes were found to fully meet requirements for selenoproteins, although they have not been annotated as selenoproteins in NCBI databases. Deduced from their basic properties, the newly found selenoproteins in the genome of Anopheles gambiae are possibly related to in vivo oxidation tolerance and protein regulation in order to interfere with anopheles' vectorial capacity of Plasmodium. This study may also provide theoretical bases for the prevention of malaria from anopheles transmission.     

Creation of the whole human genome microarray

Several companies have recently announced the availability of products that enable a scientist to probe gene expression from the entire human genome on a single DNA microarray. This review will focus on the underlying technological trends that have made this achievement possible, the particular methodologies which are employed to create such microarrays and the implications of the whole human genome microarray for future biological studies. The single genome array represents an important milestone on the path to unraveling the complexity of the cellular networks that control living processes. The microarrays being designed today may, however, become distant ancestors to the whole human genome arrays of the future as our understanding of the functioning of the human genome increases.     

Drug discovery of the future: the implications of the human genome project

The elucidation of the 3.2-gigabase human genome will have various impacts on drug discovery. The number of drug targets will increase by at least one order of magnitude and target validation will become a high-throughput process. To benefit from these opportunities, a theory-based integration of the vast amount of new biological data into models of biological systems is called for. The skills and knowledge required for genome-based drug discovery of the future go beyond the traditional competencies of the pharmaceutical industry. Cooperation with biotechnology firms and research institutions during drug discovery and development will become even more important.     

Clustering of protein domains in the human genome

We present a systematic study of the clustering of genes within the human genome based on homology inferred from both sequence and structural similarity. The 3D-Genomics automated proteome annotation pipeline () was utilised to infer homology for each protein domain in the genome, for the 26 superfamilies most highly represented in the Structural Classification Of Proteins (SCOP) database. This approach enabled us to identify homologues that could not be detected by sequence-based methods alone. For each superfamily, we investigated the distribution, both within and among chromosomes, of genes encoding at least one domain within the superfamily. The results indicate a diversity of clustering behaviours: some superfamilies showed no evidence of any clustering, and others displayed significant clustering either within or among chromosomes, or both. Removal of tandem repeats reduced the levels of clustering observed, but some superfamilies still displayed highly significant clustering. Thus, our study suggests that either the process of gene duplication, or the evolution of the resulting clusters, differs between structural superfamilies.     

CRISPR/Cas9基因组编辑技术在农业动物中的应用

CRISPR(Clustered regularly interspaced short palindromic repeats)/Cas(CRISPR associated proteins)是在细菌和古细菌中发现的一种用来抵御病毒或质粒入侵的获得性免疫系统.目前已发现的CRISPR/Cas系统包括Ⅰ,Ⅱ和Ⅲ型,其中Ⅱ型系统的组成较简单,由其改造成的CRISPR/Cas9技术已成为一种高效的基因组编辑工具.自2013年CRISPR/Cas9技术成功用于哺乳动物基因组定点编辑以来,应用该技术进行基因组编辑的报道呈现出爆发式的增长.农业动物不仅是重要的经济动物,也是人类疾病和生物医药研究的重要模式动物.本文综述了CRISPR/Cas9技术在农业动物中的研究和应用进展,简述了该技术的脱靶效应及减少脱靶的主要方法,并展望了该技术的应用前景.     

生物信息学数据库调查分析及其利用研究

从生物信息学数据库利用的角度调查分析生物信息学数据库的现状,为我国科研人员利用网上生物信息学数据库以及生物信息中心的开发提供科学依据和参考价值。研究采用网上调查的方法,对法国生物信息中心Infobiogen建立维护的生物信息学数据库目录DBcat中收录的511个数据库进行调查统计,分析其类型分布、国家分布、更新频率和获取方式;在此基础上。进一步利用欧洲分子生物学信息网(EMBnet)中30个成员国节点对生物信息学数据库利用现状进行统计分析。