基于高通量测序的植物群体基因组学研究进展

作为群体遗传学一种新的表现形式,群体基因组学是将基因组概念和技术与群体遗传学理论体系相结合,通过覆盖全基因组范围内的多态位点的分布式样推测位点特异性效应和全基因组效应,从而提升人们对微进化的理解。近年来,随着第二代高通量测序技术的出现和改进,完成基因组测序的植物种类迅速增加,大规模的重测序也随之开展。与此同时,在一些尚未完成基因组测序的植物物种中,也开展了一些平行测序。这些重测序和平行测序极大地促进了群体基因组学的发展,加深了人们对相关植物种群在基因组水平上的遗传多样性、连锁不平衡水平、选择作用、群体历史及复杂性状的分子机理等群体基因组学方面的认识。本文简要介绍了群体基因组学的概念、研究方法等,重点综述了基于高通量测序的植物群体基因组学的研究动态,展望了植物群体基因组学的发展前景并讨论了存在的问题,以期为相关研究提供借鉴和参考。     

真菌群体基因组学研究进展

近年来,随着第二代高通量测序技术的出现和发展,测序成本不断降低,完成全基因组测序的真菌物种迅速增加。以大规模测序为基础的群体基因组学,也逐渐应用于解析真菌的群体结构、物种形成、种群分化和位点特异性效应。本文综述了群体基因组学在工业真菌、病原真菌、食用真菌、共生真菌及其在表型性状遗传基础解析中的研究进展,并对其今后的发展方向进行了展望。     

复杂基因组测序技术研究进展

复杂基因组指的是无法使用常规测序和组装手段直接解析的一类基因组,通常指包含高比例重复序列、高杂合度、极端GC含量、存在难消除异源DNA污染的基因组。为了解决复杂基因组的测序和组装问题,需要分别从基因组测序实验方法、测序技术平台、组装算法与策略3个方面进行深入研究。本文详细介绍了复杂基因组测序组装相关的现有技术与方法,并结合复杂基因组经典实例介绍了复杂基因组测序的技术解决途径和发展历程,可为制订合适的复杂基因组测序策略提供参考。     

基于高通量测序的群体基因组学——植物病原真菌研究新方向

群体基因组学能够从全基因组水平揭示种群结构与进化、物种形成、适应性机制等。随着高通量技术的不断发展,基因组测序成本不断降低,大规模测序已成为可能。近几年被全基因组测序的真菌数量迅速增加,极大地促进了真菌群体基因组学的发展,加深了人们对植物病原真菌起源、遗传多样性、选择作用、致病性、毒力因子、杀菌剂抗药性、寄主专化型等生物学特性的认识。本文简要介绍了植物病原真菌的全基因测序以及比较基因组学的研究进展,重点综述了基于高通量测序的病原真菌群体基因组学的最新研究动态。群体基因组学将成为植物病原真菌一个新的研究方向。     

牛全基因组高通量测序技术研究进展

现代科技迅速发展的今天,无疑是分子生物学的世界。基因组测序是对生物的遗传结构进行分析的一种技术。作为一项尤为重要的生物技术。在近几年来得到了迅猛的发展以及应用,并取得了跨越性的进展,在很多领域取得了革命性的成就。无论是在人类疾病的防治,还是在畜牧遗传育种发面都发挥着重要的作用。本综述主要介绍了第一代测序技术、第二代测序技术以及第三代测序技术的原理,并对三者的优缺点进行了比较说明,还分别阐述了全基因组高通量技术在肉牛的起源、遗传育种与优良性状的选育和奶牛的疾病防治、生产性能的提高等方面的研究进展,对当下的高通量测序技术存在的问题进行了讨论,并对其未来进行了展望。     

饲草基因组学研究进展

相比于粮食作物,饲草基因组学研究严重滞后,限制了饲草重要农艺性状解析以及分子设计育种的进程。近年来,随着对饲草需求的增加、测序成本的大幅降低以及测序和组装技术的快速发展,许多重要饲草的基因组已被测序和分析。该文综述了豆科、禾本科和莎草科18种饲草的基因组学研究进展,并展望了饲草基因组研究未来的方向。     

高通量测序技术在动植物研究领域中的应用

高通量测序是核酸测序研究的一次革命性技术创新, 该技术以极低的单碱基测序成本和超高的数据产出量为特征, 为基因组学和后基因组学研究带来了新的科研方法和解决方案. 在动植物研究领域, 高通量测序引领了一次具有里程碑意义的科学研究模式革新, 科研人员可利用该技术在基因组、转录组和表观基因组等领域展开多层次多方面多水平研究. 本文就高通量测序技术应用于动植物基因组学和功能基因组学研究进展进行了系统阐述, 并对当前高通量测序技术的现状和热点及未来的发展趋势作了深入剖析和讨论.     

新一代测序技术的发展及应用前景

Sanger测序的提出给人类破译遗传密码提供了强有力的工具。而近几年飞速发展起来的高通量测序技术无论在成本还是效率上,都对传统测序提出了巨大的挑战。千元人类基因组计划的公布更是加快了测序研发的进程。通过下一代测序技术,科学家不仅能够绘制出各个物种的基因组图谱,还能探讨不同条件下的基因表达差异以及不同物种之间或者物种之内的序列差异,进而为传统生物学以及医学研究开辟新的视角。与此同时,随着各大测序平台的不断改进,普通实验室都有能力承担此类大型测序项目。就目前正在发展的几种高通量测序技术进行了综合阐述,并比较了各种测序技术的优缺点,最后对其应用领域作了简单介绍。     

水稻基因组测序的研究进展

水稻是最重要的粮食作物之一,世界上大约有一半的人口以水稻为主要粮食。作为基因组研究的模式植物,水稻基因组的测序工作已在世界范围内展开。此项研究工作不仅能破译水稻全基因组序列,还将有助于了解其他禾本科植物的基因组信息。本对水稻基因组测序工作进展作一综述。     

弯曲菌基因组学的研究进展

弯曲菌是世界范围内引起细菌性胃肠炎疾病的重要人兽共患病原菌,对公众健康造成严重威胁,其流行、传播、扩散的复杂性与基因组的高变异有关.全基因组测序(WGS)是一种基于基因水平的快速简便工具,可快速准确地进行物种鉴定、分析不同个体基因组间的差异、预测细菌耐药和毒力基因以及预测种群演化模型等.本文旨在对近年来全基因组测序在弯...     

Transformation of animal genomics by next-generation sequencing technologies: a decade of challenges and their impact on genetic architecture

For more than a quarter of a century, sequencing technologies from Sanger’s method to next-generation high-throughput techniques have provided fascinating opportunities in the life sciences. The continuing upward trajectory of sequencing technologies will improve livestock research and expedite the development of various new genomic and technological studies with farm animals. The use of high-throughput technologies in livestock research has increased interest in metagenomics, epigenetics, genome-wide association studies, and identification of single nucleotide polymorphisms and copy number variations. Such studies are beginning to provide revolutionary insights into biological and evolutionary processes. Farm animals, such as cattle, swine, and horses, have played a dual role as economically and agriculturally important animals as well as biomedical research models. The first part of this study explores the current state of sequencing methods, many of which are already used in animal genomic studies, and the second part summarizes the state of cattle, swine, horse, and chicken genome sequencing and illustrates its achievements during the last few years. Finally, we describe several high-throughput sequencing approaches for the improved detection of known, unknown, and emerging infectious agents, leading to better diagnosis of infectious diseases. The insights from viral metagenomics and the advancement of next-generation sequencing will strongly support specific and efficient vaccine development and provide strategies for controlling infectious disease transmission among animal populations and/or between animals and humans. However, prospective sequencing technologies will require further research and in-field testing before reaching the marketplace.     

单分子纳米孔测序技术及其应用研究进展

测序技术在通量和成本方面有了较大的改进,以单分子纳米孔测序技术为代表的第三代测序技术更是以其超长读长、实时检测和可以直接检测碱基甲基化修饰等优势在医学及生命科学等领域作出了较大贡献。文中就单分子纳米孔测序技术的原理进行了简要描述,并对其在临床、动物、植物、细菌及病毒等领域的应用和其未来的发展方向进行了讨论。     

Road transport of farm animals: effects of journey duration on animal welfare

Transport of farm animals gives rise to concern about their welfare. Specific attention has been given to the duration of animal transport, and maximum journey durations are used in legislation that seek to minimise any negative impact of transport on animal welfare. This paper reviews the relatively few scientific investigations into effects of transport duration on animal welfare in cattle, sheep, horses, pigs and poultry. From the available literature, we attempt to distinguish between aspects, which will impair welfare on journeys of any duration, such as those associated with loading, and those aspects that may be exacerbated by journey time. We identify four aspects of animal transport, which have increasing impact on welfare as transport duration increases. These relate to (i) the physiological and clinical state of the animal before transport; and - during transport - to (ii) feeding and watering; (iii) rest and (iv) thermal environment. It is thus not journey duration per se but these associated negative aspects that are the cause of compromised welfare. We suggest that with a few exceptions, transport of long duration is possible in terms of animal welfare provided that these four issues can be dealt with for the species and the age group of the animals that are transported.     

基因组选择技术在农业动物育种中的应用

基因组选择(genomic selection, GS)是畜禽经济性状遗传改良的重要方法。随着高密度SNP芯片和二代测序价格的下降,GS技术越来越多被应用于奶牛、猪、鸡等农业动物育种中。然而,降低全基因组SNP分型成本、提高基因组育种值(genomic estimated breeding value,GEBV)估计准确性仍然是GS研究的主要难题。本文从全基因组SNP分型策略和GEBV估计模型两个方面进行了综述,并对目前GS技术在主要畜禽品种中的应用现状进行了介绍,以期为GS在农业动物育种中的深入开展提供借鉴和参考。     

Use and non-use values as motivational construct dimensions for farm animal welfare: impacts on the economic outcome for the farm

This study explored how farmers’ motivation in terms of use values and/or non-use values to work with farm animal welfare are associated with the economic outcome for the farm. Use values in farm animal welfare refer to economic value derived from productivity and profitability considerations. Non-use values in farm animal welfare refer to economic value derived from good animal welfare, irrespective of the use the farmer derives from the animal, currently or in the future. The analysis was based on detailed information about the income statements of a sample of Swedish dairy farmers, obtained from the Swedish Farm Economic Survey, complemented with survey information about their perceived use and non-use values in farm animal welfare. The findings suggest that farm economic outcome is significantly associated with motivation in terms of use values, but not so much with motivation in terms of non-use values. This is interesting from a policy point of view, because it indicates that farmers with different approaches to farm animal welfare may experience different economic outcomes for their farms. Findings can, for instance, be used to strengthen farmers’ engagement in various private quality assurance standards, which generally focus on values of non-use type, by pointing to that realisation of such values will not impair the economic outcome of the farms. Moreover, findings also suggest that farmers’ economic incentives for engagement in such standards may need to be further strengthened in order to become more attractive, as findings point to that a focus on non-use values generally is not associated with more favourable economic outcomes.     

Population genomics of Sinorhizobium medicae based on low-coverage sequencing of sympatric isolates

We investigated the genomic diversity of a local population of the symbiotic bacterium Sinorhizobium medicae, isolated from the roots of wild Medicago lupulina plants, in order to assess genomic diversity, to identify genomic regions influenced by duplication, deletion or strong selection, and to explore the composition of the pan-genome. Partial genome sequences of 12 isolates were obtained by Roche 454 shotgun sequencing (average 5.3 Mb per isolate) and compared with the published sequence of S. medicae WSM 419. Homologous recombination appears to have less impact on the polymorphism patterns of the chromosome than on the chromid pSMED01 and megaplasmid pSMED02. Moreover, pSMED02 is a hot spot of insertions and deletions. The whole chromosome is characterized by low sequence polymorphism, consistent with the high density of housekeeping genes. Similarly, the level of polymorphism of symbiosis genes (low) and of genes involved in polysaccharide synthesis (high) may reflect different selection. Finally, some isolates carry genes that may confer adaptations that S. medicae WSM 419 lacks, including homologues of genes encoding rhizobitoxine synthesis, iron uptake, response to autoinducer-2, and synthesis of distinct polysaccharides. The presence or absence of these genes was confirmed by PCR in each of these 12 isolates and a further 27 isolates from the same population. All isolates had rhizobitoxine genes, while the other genes were co-distributed, suggesting that they may be on the same mobile element. These results are discussed in relation to the ecology of Medicago symbionts and in the perspective of population genomics studies.     

Global positioning system and associated technologies in animal behaviour and ecological research

Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS ‘rapid fixing’ technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives.