Value of a newly sequenced bacterial genome

Next-generation sequencing(NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting in an exponential increase in draft(partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses the factors that could be leading to the increase in the number of draft deposits and the consequent loss of relevant biological information.     

Lessons learnt on the analysis of large sequence data in animal genomics

The ’omics revolution has made a large amount of sequence data available to researchers and the industry. This has had a profound impact in the field of bioinformatics, stimulating unprecedented advancements in this discipline. Mostly, this is usually looked at from the perspective of human ’omics, in particular human genomics. Plant and animal genomics, however, have also been deeply influenced by next‐generation sequencing technologies, with several genomics applications now popular among researchers and the breeding industry. Genomics tends to generate huge amounts of data, and genomic sequence data account for an increasing proportion of big data in biological sciences, due largely to decreasing sequencing and genotyping costs and to large‐scale sequencing and resequencing projects. The analysis of big data poses a challenge to scientists, as data gathering currently takes place at a faster pace than does data processing and analysis, and the associated computational burden is increasingly taxing, making even simple manipulation, visualization and transferring of data a cumbersome operation. The time consumed by the processing and analysing of huge data sets may be at the expense of data quality assessment and critical interpretation. Additionally, when analysing lots of data, something is likely to go awry—the software may crash or stop—and it can be very frustrating to track the error. We herein review the most relevant issues related to tackling these challenges and problems, from the perspective of animal genomics, and provide researchers that lack extensive computing experience with guidelines that will help when processing large genomic data sets.     

Sequencing approaches in cancer treatment

Use of sequencing approaches is an important aspect in the field of cancer genomics, where next‐generation sequencing has already been utilized for targeting oncogenes or tumour‐suppressor genes, that can be sequenced in a short time period. Alterations such as point mutations, insertions/deletions, copy number alterations, chromosomal rearrangements and epigenetic changes are encountered in cancer cell genomes, and application of various NGS technologies in cancer research will encounter such modifications. Rapid advancement in technology has led to exponential growth in the field of genomic analysis. The $1000 Genome Project (in which the goal is to sequence an entire human genome for $1000), and deep sequencing techniques (which have greater accuracy and provide a more complete analysis of the genome), are examples of rapid advancements in the field of cancer genomics. In this mini review, we explore sequencing techniques, correlating their importance in cancer therapy and treatment.     

细胞筛选平台在人类功能基因组研究中的应用

人类基因组全序列的精细图已完成,当前生命科学面临的重要任务就是如何将基因组序列信息转化为基因的功能信息,了解生命活动的分子机理,改善人类健康,为生物技术发展提供动力 . 在一系列功能基因组研究新技术中,高通量 (high-throughput) 和高内涵 (high-content) 的细胞筛选技术平台已经显示出巨大潜力,发挥着越来越重要的作用 . 通过在体外培养的哺乳动物细胞中基因过表达或抑制基因表达,分析所产生信号传导通路和 / 或细胞表型改变,可以直接发现基因功能 . 近年来一些技术上的进展,使细胞筛选平台具有微量、自动、高效、高通量,以及可以系统研究的特点,已经成为功能基因组研究的核心方法之一 . 近 2~3 年来已经出现一批成功应用细胞筛选平台进行大规模功能基因组研究的报道 . 我国在这一领域的研究也开始起步,将对我国生物技术的源头创新研究产生深远的影响 .     

Applications of next generation sequencing in molecular ecology of non-model organisms

As most biologists are probably aware, technological advances in molecular biology during the last few years have opened up possibilities to rapidly generate large-scale sequencing data from non-model organisms at a reasonable cost. In an era when virtually any study organism can 'go genomic', it is worthwhile to review how this may impact molecular ecology. The first studies to put the next generation sequencing (NGS) to the test in ecologically well-characterized species without previous genome information were published in 2007 and the beginning of 2008. Since then several studies have followed in their footsteps, and a large number are undoubtedly under way. This review focuses on how NGS has been, and can be, applied to ecological, population genetic and conservation genetic studies of non-model species, in which there is no (or very limited) genomic resources. Our aim is to draw attention to the various possibilities that are opening up using the new technologies, but we also highlight some of the pitfalls and drawbacks with these methods. We will try to provide a snapshot of the current state of the art for this rapidly advancing and expanding field of research and give some likely directions for future developments.     

化学计量基因组学研究进展

化学计量基因组学是一个新兴的研究领域,研究基因组、转录组、蛋白质组及代谢组等组学数据中生物大分子的元素使用偏好。不同生物大分子的元素组成与数量不同,当元素供应受到限制,自然选择偏好性利用某些单体(氨基酸或核苷酸)来合成生物大分子(DNA、RNA和蛋白质等),从而减少元素成本。随着高通量测序技术和组装技术的大量应用,越来越多的宏基因组、宏转录组数据被公开报道,以及新的分析手段的应用,使得该领域蓬勃发展。作为一门新兴的交叉学科,化学计量     

The dynamics of cancer chromosomes and genomes

A key feature of cancer chromosomes and genomes is their high level of dynamics and the ability to constantly evolve. This unique characteristic forms the basis of genetic heterogeneity necessary for cancer formation, which presents major obstacles to current cancer diagnosis and treatment. It has been difficult to integrate such dynamics into traditional models of cancer progression. In this conceptual piece, we briefly discuss some of the recent exciting progress in the field of cancer genomics and genome research. In particular, a re-evaluation of the previously disregarded non-clonal chromosome aberrations (NCCAs) is reviewed, coupled with the progress of the detection of sub-chromosomal aberrations with array technologies. Clearly, the high level of genetic heterogeneity is directly caused by genome instability that is mediated by stochastic genomic changes, and genome variations defined by chromosome aberrations are the driving force of cancer progression. In addition to listing various types of non-recurrent chromosomal aberrations, we discuss the likely mechanism underlying cancer chromosome dynamics. Finally, we call for further examination of the features of dynamic genome diseases including cancer in the context of systems biology and the need to integrate this new knowledge into basic research and clinical applications. This genome centric concept will have a profound impact on the future of biological and medical research.     

Massive parallel sequencing in animal genetics: wherefroms and wheretos

Next generation sequencing (NGS) has revolutionized genomics research, making it difficult to overstate its impact on studies of Biology. NGS will immediately allow researchers working in non‐mainstream species to obtain complete genomes together with a comprehensive catalogue of variants. In addition, RNA‐seq will be a decisive way to annotate genes that cannot be predicted purely by computational or comparative approaches. Future applications include whole genome sequence association studies, as opposed to classical SNP‐based association, and implementing this new source of information into breeding programmes. For these purposes, one of the main advantages of sequencing vs. genotyping is the possibility of identifying copy number variants. Currently, experimental design is a topic of utmost interest, and here we discuss some of the options available, including pools and reduced representation libraries. Although bioinformatics is still an important bottleneck, this limitation is only transient and should not deter animal geneticists from embracing these technologies.     

The naturalist in a world of genomics

Functional genomics provides new opportunities to address issues of fundamental interest in evolutionary biology and suggests many new research directions that are ripe for evolutionary investigation. New types of data, and the ability to study biological processes from a whole genome perspective, are likely to have a profound impact on evolutionary biology and ecology. To illustrate, we discuss how genomewide gene expression studies can be used to reformulate questions about trade-offs and pleiotropy. We then touch on some of the new research opportunities that the application of functional genomics affords to evolutionary biologists. We end with some brief notes about how evolutionary biology and comparative approaches will probably have an impact on functional genomics.     

Status of genome projects for nonpathogenic bacteria and archaea

Since the first microbial genome was sequenced in 1995, 30 others have been completed and an additional 99 are known to be in progress. Although the early emphasis of microbial genomics was on human pathogens for obvious reasons, a significant number of sequencing projects have focused on nonpathogenic organisms, beginning with the release of the complete genome sequence of the archaeon Methanococcus jannaschii in 1996. The past 18 months have seen the completion of the genomes of several unusual organisms, including Thermotoga maritima, whose genome reveals extensive potential lateral transfer with archaea; Deinococcus radiodurans, the most radiation-resistant microorganism known; and Aeropyrum pernix, the first Crenarchaeota to be completely sequenced. Although the functional characterization of genomic data is still in its initial stages, it is likely that microbial genomics will have a significant impact on environmental, food, and industrial biotechnology as well as on genomic medicine.     

An Integrated Approach for Analyzing Clinical Genomic Variant Data from Next-Generation Sequencing

Next-generation sequencing (NGS) technologies provide the potential for developing high-throughput and low-cost platforms for clinical diagnostics. A limiting factor to clinical applications of genomic NGS is downstream bioinformatics analysis for data interpretation. We have developed an integrated approach for end-to-end clinical NGS data analysis from variant detection to functional profiling. Robust bioinformatics pipelines were implemented for genome alignment, single nucleotide polymorphism (SNP), small insertion/deletion (InDel), and copy number variation (CNV) detection of whole exome sequencing (WES) data from the Illumina platform. Quality-control metrics were analyzed at each step of the pipeline by use of a validated training dataset to ensure data integrity for clinical applications. We annotate the variants with data regarding the disease population and variant impact. Custom algorithms were developed to filter variants based on criteria, such as quality of variant, inheritance pattern, and impact of variant on protein function. The developed clinical variant pipeline links the identified rare variants to Integrated Genome Viewer for visualization in a genomic context and to the Protein Information Resource’s iProXpress for rich protein and disease information. With the application of our system of annotations, prioritizations, inheritance filters, and functional profiling and analysis, we have created a unique methodology for downstream variant filtering that empowers clinicians and researchers to interpret more effectively the relevance of genomic alterations within a rare genetic disease.     

Matrix-assisted laser desorption/ionisation, time-of-flight mass spectrometry in genomics research

The beginning of this millennium has seen dramatic advances in genomic research. Milestones such as the complete sequencing of the human genome and of many other species were achieved and complemented by the systematic discovery of variation at the single nucleotide (SNP) and whole segment (copy number polymorphism) level. Currently most genomics research efforts are concentrated on the production of whole genome functional annotations, as well as on mapping the epigenome by identifying the methylation status of CpGs, mainly in CpG islands, in different tissues. These recent advances have a major impact on the way genetic research is conducted and have accelerated the discovery of genetic factors contributing to disease. Technology was the critical driving force behind genomics projects: both the combination of Sanger sequencing with high-throughput capillary electrophoresis and the rapid advances in microarray technologies were keys to success. MALDI-TOF MS-based genome analysis represents a relative newcomer in this field. Can it establish itself as a long-term contributor to genetics research, or is it only suitable for niche areas and for laboratories with a passion for mass spectrometry? In this review, we will highlight the potential of MALDI-TOF MS-based tools for resequencing and for epigenetics research applications, as well as for classical complex genetic studies, allele quantification, and quantitative gene expression analysis. We will also identify the current limitations of this approach and attempt to place it in the context of other genome analysis technologies.     

高通量测序技术在农作物全基因组序列测定中的应用概览

近几年飞速发展的高通量测序技术(next generation sequencing,NGS)在生命科学研究的各个领域充分展现了其低成本、高通量和应用面广等优势。在现代农业生物技术领域,利用高通量测序技术,科学家们不仅能更经济而高效对农作物、模式植物或不同栽培品种进行深入的全基因组测序、重测序,也可以对成百上千的栽培品种进行高效而准确的遗传差异分析、分子标记分析、连锁图谱分析、表观遗传学分析、转录组分析,进而改进农作物的育种技术,加快新品种的育种研究。其中,获得农作物的全基因组序列是其他研究和分析的基础。本文通过介绍近年来发表的一些利用高通量测序技术进行的农作物全基因组测定和组装的工作,展示高通量测序技术在现代农业生物技术领域的广泛前景以及其建立起来的研究基础。     

Genomics: Applications,Challenges, and Opportunities for the U.S. Environmental Protection Agency

Genomics information has great potential to enhance assessment of risks to human health and the environment. Although understanding genomic responses with respect to adverse ecological and human health outcomes is not, as yet, established, it is important to consider the likely future impacts of genomics technologies on risk assessment and decision-making. Four areas are identified as those likely to be influenced by the generation of genomics information within, and the submission of such information to, the U.S. Environmental Protection Agency (USEPA): risk assessment, prioritization of contaminants and contaminated sites, monitoring, and reporting provisions. For each of these risk assessment and regulatory applications, representative activities are presented to illustrate the application. Three major challenges for the USEPA associated with genomics are also identified in the areas of research, technical development, and capacity. The USEPA's initial activities to address these challenges are discussed. The Agency recognizes it must be prepared to use genomics information, and that many scientific, policy, ethical, and legal concerns will need to be addressed. The USEPA also recognizes it is essential to continue to collaborate with other federal agencies, academia, the regulated community, and other stakeholders in order to benefit from ongoing advances in genomics in the wider scientific and regulatory communities.     

Sweating the small stuff: microRNA discovery in plants

The class of small RNAs known as microRNAs (miRNAs) has a demonstrated role in the negative regulation of gene expression in both plants and animals. These small molecules have been shown to play a critical role in a wide range of developmental and physiological pathways. Although hundreds of different miRNAs have now been identified using cloning and computational approaches, characterization of their targets and biological roles has been more limited. New sequencing technologies promise to accelerate the sequencing of small RNAs and additional genetic and genomic strategies are being applied to assess their regulatory function on RNA targets. These technologies will enable the identification of large numbers of small RNAs from diverse species, and comparative genomics approaches based on these data are likely to identify additional miRNAs. Combined with bioinformatics and experimental approaches to separate miRNAs from short-interfering RNAs (siRNAs), the pace of miRNA discovery is likely to accelerate, leading to an improved understanding of miRNA function and biological significance.     

Targeted sequence capture as a powerful tool for evolutionary analysis1

Next-generation sequencing technologies (NGS) have revolutionized biological research by significantly increasing data generation while simultaneously decreasing the time to data output. For many ecologists and evolutionary biologists, the research opportunities afforded by NGS are substantial; even for taxa lacking genomic resources, large-scale genome-level questions can now be addressed, opening up many new avenues of research. While rapid and massive sequencing afforded by NGS increases the scope and scale of many research objectives, whole genome sequencing is often unwarranted and unnecessarily complex for specific research questions. Recently developed targeted sequence enrichment, coupled with NGS, represents a beneficial strategy for enhancing data generation to answer questions in ecology and evolutionary biology. This marriage of technologies offers researchers a simple method to isolate and analyze a few to hundreds, or even thousands, of genes or genomic regions from few to many samples in a relatively efficient and effective manner. These strategies can be applied to questions at both the infra- and interspecific levels, including those involving parentage, gene flow, divergence, phylogenetics, reticulate evolution, and many more. Here we provide a brief overview of targeted sequence enrichment, and emphasize the power of this technology to increase our ability to address a wide range of questions of interest to ecologists and evolutionary biologists, particularly for those working with taxa for which few genomic resources are available.     

Adaptation genomics: the next generation

Understanding the genetics of how organisms adapt to changing environments is a fundamental topic in modern evolutionary ecology. The field is currently progressing rapidly because of advances in genomics technologies, especially DNA sequencing. The aim of this review is to first briefly summarise how next generation sequencing (NGS) has transformed our ability to identify the genes underpinning adaptation. We then demonstrate how the application of these genomic tools to ecological model species means that we can start addressing some of the questions that have puzzled ecological geneticists for decades such as: How many genes are involved in adaptation? What types of genetic variation are responsible for adaptation? Does adaptation utilise pre-existing genetic variation or does it require new mutations to arise following an environmental change?     

A genomic point-of-view on environmental factors influencing the human brain methylome

The etiologic paradigm of complex human disorders such as autism is that genetic and environmental risk factors are independent and additive, but the interactive effects at the epigenetic interface are largely ignored. Genomic technologies have radically changed perspective on the human genome and how the epigenetic interface may impact complex human disorders. Here, I review recent genomic, environmental, and epigenetic findings that suggest a new paradigm of “integrative genomics” in which genetic variation in genomic size may be impacted by dietary and environmental factors that influence the genomic saturation of DNA methylation. Human genomes are highly repetitive, but the interface of large-scale genomic differences with environmental factors that alter the DNA methylome such as dietary folate is under-explored. In addition to obvious direct effects of some environmental toxins on the genome by causing chromosomal breaks, non-mutagenic toxin exposures correlate with DNA hypomethylation that can lead to rearrangements between repeats or increased retrotransposition. Since human neurodevelopment appears to be particularly sensitive to alterations in epigenetic pathways, a further focus will be on how developing neurons may be particularly impacted by even subtle alterations to DNA methylation and proposing new directions towards understanding the quixotic etiology of autism by integrative genomic approaches.