454测序技术开发微卫星标记的研究进展

第二代测序技术(454测序为例)已成为测定基因组序列的一种成熟技术.454测序亦可应用于目标DNA区域分析,因此可用作微卫星标记的开发.较传统方法而言,具有便捷、高效等特点.目前,运用454技术进行基因组测序或转录组测序开发微卫星标记,用以研究种群生态学、构建遗传图谱等得到越来越多的重视和应用.综述了454测序技术在开发微卫星标记上的应用,并根据其优缺点对其应用前景进行了展望,旨在为应用454测序开发微卫星提供参考.     

目标序列捕获技术及其应用

耗资30 亿美元历时10 余年完成的人类基因组计划(Human Genome Project,HGP)给基因组学研究带来了翻天覆地的变化,通过测定人类基因组DNA 的序列,探寻基因在染色体上的位置,明确基因的结构和功能,解读人类的全部遗传信息,人类第一次在分子水平上全面认识自我.在这期间,建立了两项非常重要的高通量技术:基因芯片和新一代测序技术.这两种技术进一步结合,就产生了一种新的解决方案:目标序列捕获测序技术.新一代测序技术的发展和成功应用使得普通实验室对整个人类基因组进行测序成为可能,由此,科学家们提出了千元人类基因组计划①.     

基于微生物基因组序列开发疫苗的研究进展与分析

疫苗的问世,使得许多危害人类健康的疾病得到了控制,对全世界人类预防和治疗疾病方面发挥了不可磨灭的作用,而一些特殊的病原体所引起的人类疾病的危害性是极大的,但采用传统的方法根本无法制备其安全有效的疫苗。直到20世纪末,微生物全基因组测序、生物信息学分析、蛋白质组学和DNA芯片技术的发展为疫苗研究领域带来了前所未有的变革。基于微生物基因组序列开发疫苗的新方法应运而生,为采用传统方法无法取得成功的疫苗的制备带来了光明。本文从基于微生物基因组序列开发疫苗的可行性、原理、实验方法以及应用等方面进行了综述。     

名刊封面

《细胞》2008.8尼安德特人线粒体基因组问世高通量454测序技术被广泛应用于分析古代DNA样本,为复原古代DNA提供了可能。近日,来自德国、美国、克罗地亚和芬兰的科学家发表了他们的最新研究结果,通过454测序技术,科学家得到了一个尼安德特个体的完整线粒体DNA基因组序列。尽管科学家相信尼安德特人是最接近现代人类的原始人种,但是关于他们与现代人类之间的精确关系却一直存在争论。     

一种结合单张芯片序列捕获和高通量测序技术测序外显子组的方法

随着高通量测序技术的发展,全外显子测序已经成为一种研究人类疾病的重要方法.本文展示了一种通过Nimblegen2.1M芯片进行外显子DNA序列捕获和高通量测序的方法,包括两步法文库制备.测序的平均覆盖深度达33倍时,95.6%的34M目标区域得到均衡覆盖,特异性达到80%.对比全基因组鸟枪法测序的结果,此方法在检测SNP时的假阳性率为0.97%,假阴性率为6.27%.本方法对于全基因组扩增的DNA也适用.结果显示,全外显子测序技术可以在大规模的群体研究和医学研究中起到重要作用.     

一种基于多重PCR的人类线粒体基因组高通量测序方法

人类线粒体基因组DNA(mtDNA)是一个16569 bp的双链闭合环状DNA分子,具有母系遗传、多拷贝、高异质性及高变异率等特点,是研究人类遗传和进化上广泛使用的分子标记.近几年,高通量测序技术的出现,使得在短时间内准确测定mtDNA序列成为可能;但目前常用的高通量测序建库方法操作复杂、研究费用相对较高.基于多重PCR扩增的测序方法具有高效率、高灵敏度、低成本的特点,因而适用于大规模线粒体基因组的变异检测分析.利用73个相互重叠的扩增子通过多重PCR方法来扩增中国人的线粒体全基因组,在扩增片段两端连接特定的接头序列,然后在IlluminaHiSeq X Ten平台上进行高通量测序.对获得的测序数据分析发现,mtDNA每个位点的测序深度均达到2000×以上;当测序深度为100×时,所有样本的序列覆盖度都达到100%;数据质量适用于后续的变异检测分析.利用本研究建立的基于多重PCR的二代测序方法无需片段化即可直接上机测序,在复杂遗传病的研究中有着广泛的应用前景.     

“反向免疫学”与免疫功能基因的发现

人类基因组测序的结束为生命科学领域展开了全新的一章.尽管已经得到了人类基因组的序列,但是隐藏在DNA序列中的功能基因,它们之间的相互作用以及对整个机体的意义大部分有待发掘.近些年来形成的“反向生物学”为免疫功能基因的发现、功能的研究及其应用价值提供了一套全新的技术与思路.     

STRs-PCR分型技术在法医学上的应用

短串联重复序列 (STRs)是广泛存在于人类基因组的一类具有长度多态性的DNA序列 ,属高信息基因座。概述了STRs PCR的法医学应用特点以及它们在亲子鉴定、个体识别等领域的法医学应用及其理论基础、现状和前景。     

全基因组外显子测序及其应用

近年来,众多研究小组开展了大量的全基因组关联研究(Genome-wide association studies,GWAS),发现并鉴定了许多与复杂疾病/性状相关联的遗传变异,为复杂疾病发病机制的研究提供了重要线索。由于GWAS的结果存在假阳性、假阴性、检测到的单核苷酸多态性很少位于功能区以及对稀有变异和结构变异不敏感等问题,导致了其应用的局限性。而新一代测序技术的进步,促进了全基因组测序和全基因组外显子测序的快速发展,为解决上述问题提供了契机。全基因组外显子测序是利用序列捕获技术将全基因组外显子区域DNA捕捉并富集后进行高通量测序的基因组分析方法。由于其具有对常见和罕见变异高灵敏度,能发现外显子区绝大部分疾病相关变异以及仅需要对约1%的基因组进行测序等优点,促使全基因组外显子测序成为鉴定孟德尔疾病的致病基因最有效的策略,也被运用于复杂疾病易感基因的研究和临床诊断中。     

2007影响人类生命健康的6大生物科技进展

进展一：个体基因测序不再是梦人类第一个个体基因组排序已经完成。利用基因组排序技术,研究人员成功绘制了著名科学家克雷格·文特尔的一个完整的DNA蓝图。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.