染色体整合系统在多价疫苗构建中的应用研究

通过同源重组将编码异源抗原的DNA整合到减毒的鼠伤寒沙门氏菌的染色体上,获得了表达霍乱毒素B亚单位（CTB）的双价活疫苗候选株。该系统包括两个步骤：首先将GisOG缺失突变的DNA片段整合进鼠伤寒沙门氏菌疫苗候选株SL3261的染色体上,得到His营养缺陷型。然后,用带有CTB抗原基因的完整HisOGDNA片段置换HisOG缺失的DNA片段,获得表达CTB的His回复的SL3261菌株（命名为TT201）。Southern杂交证明,TT201菌株的染色体带有CTB抗原基因。Westernblot分析表明,TT201菌株能表达CTB,且具有很好的稳定性。用重组菌株口服免疫接种小鼠,能够激发抗CTB抗体的产生。TT201菌株是一种潜在的双价疫苗候选株。     

人类基因组分析中新的分子工具-YAC

通常用于ＤＮＡ克隆的载体,如质粒、λ噬菌体载体ｃｏｓ质粒（ｃｏｓｍｉｄ）等,其容量５０ｋｂ,对于多数基因或某些小的基因簇,这个容量是足够的。但对于人类基因组研究和某些大基因的克隆,这些载体就有相当的局限性。例如人类第Ⅷ因子基因编码凝血因子,它的缺陷可...     

人类基因组辞汇

人类基因组辞汇柴建华（复旦大学遗传学研究所上海２００４３３）Ａｄｅｎｉｎｅ（Ａ）腺嘌呤,一种含氯碱基,碱基对（ｂａｓｅｐａｉｒ）的一个成员。例如：Ａ-Ｔ（腺嘌呤－胸腺嘧啶）。Ａｌｌｅｉｅｓ等位基因。遗传座位的两种不同形式。每一遗传座位的一个等位基因分别由双亲中的一个遗传而来。例如决定眼睛颜色的座位,某一等位基因可能决定眼睛呈棕色。ＡｌｕｓｅｑｕｅｎｃｅＡｌｕ）顺序。     

从DNA双螺旋到人类基因组

从ＤＮＡ双螺旋到人类基因组朱立煌中国科学院遗传研究所１９５３年Ｗａｔｓｏｎ和Ｃｒｉｃｋ提出ＤＮＡ结构的双螺旋模型,阐明了遗传物质的复制机制,从而开创了用生物大分子的结构和功能来解释生命现象的新时期。ＤＮＡ双螺旋宛如一支光芒四射的火炬指引着人们去揭示生物的各种奥密。四十年来分子生物学,遗传学和生物化学的成就接踵而至,新发现层出不穷,新思想和新技术不断涌现,几乎囊括了诺贝尔生理学医学奖的大半而且常常名列诺贝尔化学奖的榜首。     

人类性染色体特异ＤＮＡ对三种鱼类染色体的描绘

染色体描绘是研究基因组进化的强有力手段之一,用人Ｘ和Ｙ染色体文库特异ＤＮＡ为探针,对３种硬骨鱼类－刺鳅、黄鳝和斑马鱼的有丝分裂中期裂染色体进行了描绘研究,结果表明,在这３种鱼类的染色体组中都发现有人Ｘ染色体特DN的同源片段,它们散布在几对同源染色体中,但用人Ｙ染色体ＤＮ描绘这３种鱼类染色体时,则没有检测出可见的同源片段。同时对从低等脊椎动物到人类的Ｘ染色体进化过程进行了进一步探讨。     

人类疱疹病毒6型基因组的染色体整合及其临床意义

人类疱疹病毒6型(Human herpesvirus 6,HHV-6)是双链DNA病毒,其原发感染引起婴幼儿急疹,潜伏感染后的再激活亦引起多种严重疾患。近来,该病毒特有的潜伏感染形式—病毒基因组的宿主染色体整合(包括机制及临床相关性)被不断报道。HHV-6基因组的末端区域含有端粒重复序列,病毒基因组通过该重复序列整合到宿主细胞染色体中建立潜伏感染。当宿主免疫力受到抑制时,整合于宿主染色体上的病毒基因组会再次活化,引起疾患。本文综述了HHV-6基因组染色体整合的主要机制及临床意义。     

利用GeneHub软件分析人类染色体相邻基因的表达相关性

利用我们研制的基因信息融合分析软件GeneHub,按染色体开窗的方法将人类基因组沿着染色体划分为一系列基因群,用不同的相关测度(Pearson相关、Spearman秩相关、欧氏距离)考察这些基因群中所有基因间在二套独立的基因表达谱数据中的平均表达相关性。实验结果表明,与随机基因群相比,染色体上的邻近基因具有显著的表达相关性。约有40％的被检测基因包含于我们检测到的邻近相似表达基因群中。该现象提示真核生物中的基因存在模块化的共表达趋势。     

多维度基因组信息:起源、内涵与技术瓶颈

近年来发展起来的染色体多维结构研究很快就遇到了概念盲区和技术瓶颈,有必要在较高级的思维层次加以澄清和深入探讨.虽然生命可能起源于操作(基因组DNA以外的大小生物分子)而非信息(基因组DNA),但是当DNA被选择来承载信息后(或同时),其操作和平衡功能又分别在不同层面上(不同谱系、物种、细胞、染色质、基因)以不同程度体现...     

9种新的人类染色体异常核型报告

发现９种新的人类染色体异常核型,分别为：４６,ＸＸ,ｔ（２;１０）（ｑ３３;ｑ１１）;４６,ＸＹ,ｔ（１０;１２）（ｑ２６;ｑ２２）;４６,ＸＹ,ｔ（６;１５）（ｐ２３;ｑ２３）;４６,ＸＹ,ｔ（１;６）（ｐ３６;ｑ２１）;４６,ＸＹ,ｔ（１;１９）（ｐ３２;ｐ１３）;４６,ＸＹ,ｔ（１６;１８）（ｑ２２;ｑ２１）;４６,ＸＹ,ｉｎｖ（１）（ｐ３６ｑ２５）;４６,ＸＹ,ｔ（１３;１７）（ｑ１２;ｑ２５）;４６,ＸＹ,ｔ（１５;２１）（ｑ２６;ｑ１１）。异常核型是导致自然流产和不育的原因。     

Molecular genetics of Streptococcus thermophilus

Abstract The metabolism and genetics of Streptococcus thermophilus (presently Streptococcus salivarius ssp. thermophilus ) have only been investigated recently despite its widespread use in milk fermentation processes. The development of recombinant DNA technology has allowed impressive progress to be made in the knowledge of thermophilic dairy streptococci. In particular, it has permitted a careful analysis of phenotypically altered variants which were derived from a mother strain by plasmid or chromosomal DNA reorganization. While natural phage defense mechanisms of S. thermophilus remain poorly documented, information on the bacteriophages responsible for fermentation failures has accumulated. The lysogenic state of two S. thermophilus strains has also been demonstrated for the first time. Gene transfer techniques for this species have been established and improved to the point that targeted manipulation of their chromosomal determinants is now feasible. Cloning and expression vectors have been constructed, and a few heterologous genes were successfully expressed in S. thermophilus . The first homologous genes, involved in carbohydrate utilization, have been cloned and sequenced, shedding some light on the molecular organization of key metabolic steps.     

Potential for germ line transmission after intramyocardial gene delivery by adeno-associated virus

Intramyocardial injection of adeno-associated virus (AAV) has been shown to be an effective strategy for cardiac gene delivery. This approach leads to long-term gene expression in the heart, offering the possibility of chronic gene therapy. However, the long-term safety of this approach with regard to vector bio-distribution and extracardiac transgene expression has not been evaluated. To examine these issues, 8-week-old male Sprague-Dawley rats were injected intramyocardially with either 4x10(11) particles of AAV-2-lacZ or saline at five locations in the anterioposterior apical region of the left ventricle. Animals were sacrificed at 3 and 6 months after gene transfer, tissues were harvested and analyzed for lacZ expression by semi-quantitative RT-PCR and beta-galactosidase activity using X-gal staining. We observed high level of transgene expression in the myocardium at 3 months after gene transfer, which persisted up to 6 months of follow-up. Also, significantly we detected lacZ expression and beta-galactosidase activity in extracardiac tissues such as liver, kidney, and testes at 6 months. More significantly, late transgene expression was detected in cellular elements of the seminiferous tubule, including Sertoli cells and spermatogonia like cells. These data demonstrate the efficacy of AAV-2 delivery for long-term myocardial gene therapy, but raise concerns about the possibility of ectopic transgene expression and germ cell line infection.     

Radiation-induced chromosomal instability and gene expression profiling: searching for clues to initiation and perpetuation

Radiation-induced genomic instability (RIGI) manifests in the progeny of cells surviving ionizing radiation (IR), and can be measured using such endpoints as delayed mutation, micronuclei formation, and chromosomal instability. The frequency of RIGI is relatively high, exceeding the gene mutation rate of IR by orders of magnitude, leading to conjecture that a gene mutation is not the cause of the phenotype. We have started to explore whether differential gene expression patterns are associated with the instability phenotype, in order to shed light on its initiation and perpetuation. Using GM10115 human-hamster hybrid-derived chromosomally stable and radiation-induced unstable clones, gene expression patterns were analyzed using microarray analysis. Two methods were used to find differentially expressed genes, and all candidate genes identified by these methods were under-expressed relative to the chromosomally stable reference sample. Among this set differentially expressed genes identified were two candidates with a relationship to the ubiquitin/proteasome pathway. While follow-up gene expression analyses have confirmed the under-expression of these two genes in some of our chromosomally unstable clones, preliminary functional studies have been unable to demonstrate a link to instability. It is anticipated that as we apply this technology to the study of radiation-induced genomic instability, clues to its onset will be revealed, ultimately contributing to a greater understanding of the mechanisms of radiation carcinogenesis.     

Quantitative analysis of isoprenoid diphosphate intermediates in recombinant and wild-type Escherichia coli strains

In biotechnology, the heterologous biosynthesis of isoprenoid compounds in Escherichia coli is a field of great interest and growth. In order to achieve higher isoprenoid yields in heterologous E. coli strains, it is necessary to quantify the pathway intermediates and adjust gene expression. In this study, we developed a precise and sensitive nonradioactive method for the simultaneous quantification of the isoprenoid precursors farnesyl diphosphate (FPP) and geranylgeranyl diphosphate (GGPP) in recombinant and wild-type E. coli cells. The method is based on the dephosphorylation of FPP and GGPP into the respective alcohols and involves their in situ extraction followed by separation and detection using gas chromatography–mass spectrometry. The integration of a geranylgeranyl diphosphate synthase gene into the E. coli chromosome leads to the accumulation of GGPP, generating quantities as high as those achieved with a multicopy expression vector. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. T. Vallon and S. Ghanegaonkar contributed equally to this work.     

Re-analysis of data and its integration

To understand a biological process it is clear that a single approach will not be sufficient, just like a single measurement on a protein--such as its expression level--does not describe protein function. Using reference sets of proteins as benchmarks different approaches can be scaled and integrated. Here, we demonstrate the power of data re-analysis and integration by applying it in a case study to data from deletion phenotype screens and mRNA expression profiling.     

混合表型急性白血病的细胞及分子遗传学研究进展

混合表型急性白血病(mixed-phenotype acute leukemia, MPAL)是一类同时表达不止一个谱系特异性抗原的恶性克隆性疾病,发生率低,仅占急性白血病的2%~5%。多数MPAL患者可检测出克隆性染色体异常及分子遗传学改变,其中一些特异性异常如t(9;22)(q34;q11)及KMT2A重排在MPAL的诊断分型、靶向治疗及预后判断中具有重要的指导意义。近年来,随着全基因组测序、全外显子测序、靶向测序及单核苷酸多态性-微阵列比较基因组杂交等分子生物学技术的广泛应用,人们发现一些新的分子遗传学异常如ZNF384重排及WT1基因突变等也与疾病的发生发展及预后密切相关。这些发现进一步丰富了对MPAL发病机制的认识。现将有关MPAL细胞及分子遗传学的研究进展进行综述。