Systemic delivery of human growth hormone by injection of genetically engineered myoblasts

A recombinant gene encoding human growth hormone (hGH) was stably introduced into cultured myoblasts with a retroviral vector. After injection of genetically engineered myoblasts into mouse muscle, hGH could be detected in serum for 3 months. The fate of injected myoblasts was assessed by coinfecting the cells with two retroviral vectors, one encoding hGH and the other encoding beta-galactosidase from Escherichia coli. These results provide evidence that myoblasts, which can fuse into preexisting multinucleated myofibers that are vascularized and innervated, may be advantageous as vehicles for systemic delivery of recombinant proteins.     

论基因工程化食品安全性

基因工程化食品安全性在我国还是个新论题，文中从生物体内细胞的基因所含有的控制信息多重性和复杂性的角度，论述对控制信息结构及作用的困难性和局限性，论证了基因重组引起遗传基因变异的可能性，并通过实例，进一步证实遗传基因变异及控制给人类带来的危害，启发人们对基因工程化食品安全性加以关注。     

Implantation of genetically engineered fibroblasts into mice: implications for gene therapy

In a variety of human genetic diseases, replacement of the absent or defective protein provides significant therapeutic benefits. As a model for a somatic cell gene therapy system, cultured murine fibroblasts were transfected with a human growth hormone (hGH) fusion gene and cells from one of the resulting clonal lines were subsequently implanted into various locations in mice. Such implants synthesized and secreted hGH, which was detectable in the serum. The function of the implants depended on their location and size, and on the histocompatibility of the donor cells with their recipients. The expression of hGH could be modified by addition of regulatory effectors, and, with appropriate immunosuppression, the implants survived for more than 3 months. This approach to gene therapy, here termed "transkaryotic implantation," is potentially applicable to many genetic diseases in that the transfected cell line can be extensively characterized prior to implantation, several anatomical sites are suitable for implantation, and regulated expression of the gene of therapeutic interest can be obtained.     

全球转基因作物的产量和销量

从1994年到现在,全世界转基因作物的种植生产和消费已经超过20年。转基因作物刚开始出现便立即被农民所接受。单单在2013年,全世界范围内包括棉花、玉米、大豆、油菜、甜菜和苜蓿在内的转基因作物种植面积已高达1.75亿hm2,有14个国家的转基因作物种植面积超过50万hm2。绝大多数转基因作物的两个典型优点是抗除草剂和抗虫。主要生产国的转基因作物普及率已经达到90%。如今,转基因作物在发达国家的种植面积比发展中国家更大。截至目前,还没有关于人类消费转基因作物以及含转基因成分食品的数据统计,绝大部分(约90%)的主要转基因作物被用作动物饲料,少数转基因作物,如木瓜、南瓜及甜玉米则被直接消费,油、淀粉、高果糖甜味剂、蔗糖和卵磷脂等来源于转基因作物的原料普遍被应用于食品产业。在美国超市,高达70%的产品中含有转基因成分,很多其他国家的人们也在消费这样的产品,尤其是那些没有要求转基因标识的国家和地区。在许多国家,一些非政府组织经常散布关于转基因食物的谣言,以达到阻挠公众接受转基因食物和转基因作物商业化的目的。遗憾的是,政府决策者的决定常常基于政治考虑,而非出于转基因作物的重要科学意义。     

Ordering of quantum dots using genetically engineered viruses

A liquid crystal system was used for the fabrication of a highly ordered composite material from genetically engineered M13 bacteriophage and zinc sulfide (ZnS) nanocrystals. The bacteriophage, which formed the basis of the self-ordering system, were selected to have a specific recognition moiety for ZnS crystal surfaces. The bacteriophage were coupled with ZnS solution precursors and spontaneously evolved a self-supporting hybrid film material that was ordered at the nanoscale and at the micrometer scale into approximately 72-micrometer domains, which were continuous over a centimeter length scale. In addition, suspensions were prepared in which the lyotropic liquid crystalline phase behavior of the hybrid material was controlled by solvent concentration and by the use of a magnetic field.     

The ecological risks and benefits of genetically engineered plants

Discussions of the environmental risks and benefits of adopting genetically engineered organisms are highly polarized between pro- and anti-biotechnology groups, but the current state of our knowledge is frequently overlooked in this debate. A review of existing scientific literature reveals that key experiments on both the environmental risks and benefits are lacking. The complexity of ecological systems presents considerable challenges for experiments to assess the risks and benefits and inevitable uncertainties of genetically engineered plants. Collectively, existing studies emphasize that these can vary spatially, temporally, and according to the trait and cultivar modified.     

环境生物修复中高效基因工程菌的构建策略

通过对环境污染物的生物降解机制及妨碍污染物降解的因素进行分析,提出了几种高效基因工程降解菌的构建策略,包括重组污染物降解基因以优化污染物降解途径、重组污染物摄入相关基因以改善对污染物的生物可利用性和重组环境不利因子抵抗基因以增强其环境适应性等.     

基因工程牛生长激素高密度发酵表达的研究

通过对重组牛生长激素基因工程大肠杆菌摇瓶和5、30 L发酵罐发酵表达的研究,建立了基因工程牛生长激素的高密度发酵表达工艺,菌体密度最高可达到OD550=120,rbIL-2的表达量占菌体总蛋白的20%以上.     

Cancer regression in patients after transfer of genetically engineered lymphocytes

Through the adoptive transfer of lymphocytes after host immunodepletion, it is possible to mediate objective cancer regression in human patients with metastatic melanoma. However, the generation of tumor-specific T cells in this mode of immunotherapy is often limiting. Here we report the ability to specifically confer tumor recognition by autologous lymphocytes from peripheral blood by using a retrovirus that encodes a T cell receptor. Adoptive transfer of these transduced cells in 15 patients resulted in durable engraftment at levels exceeding 10% of peripheral blood lymphocytes for at least 2 months after the infusion. We observed high sustained levels of circulating, engineered cells at 1 year after infusion in two patients who both demonstrated objective regression of metastatic melanoma lesions. This study suggests the therapeutic potential of genetically engineered cells for the biologic therapy of cancer.     

Utilizing a social ethic toward the environment in assessing genetically engineered insect-resistance in trees

Social policies are used to regulate how members of a society interact and share resources. If we expand our sense of community to include the ecosystem of which we are a part, we begin to develop an ethical obligation to this broader community. This ethic recognizes that the environment has intrinsic value, and each of us, as members of society, are ethically bound to preserve its sustainability. In assessing the environmental risks of new agricultural methods and technologies, society should not freely trade economic gains for ecological damage, but rather seek practices that are compatible with ecosystem health. This approach is used to evaluate the environmental risks associated with genetically engineered insect-resistant trees. The use of insect-resistant trees is a biologically based pest control strategy that has several advantages over pesticide use. However, the use of genetically engineered trees presents particular ecological concerns because the trees are long lived and often are not highly domesticated. The main environmental concerns reviewed include: (1) adaptation of pests to the trees, leading to a non-sustainable agricultural practice, (2) transgenic trees producing environmental toxins, (3) insect resistance enhancing the invasiveness of the tree, causing it to become weedy or invade wild habitats, and (4) transfer of the transgene to wild or feral relatives of the tree, possibly increasing the invasiveness of weeds or wild plants. Some methods are available to offset these risks; however, the environmental risks associated with this technology have been poorly researched and need to be more clearly identified so that when we evaluate the risks, it is based on the best information obtainable. To fulfil an ethical obligation to the environment, public policies and government regulations are needed to preserve the sustainability of both the environment and the future of our production systems. A better understanding of both the ecological issues and of genetic engineering in general are needed on the part of citizens and policy makers alike to ensure that sound environmental decisions are made. Otherwise, the environmental benefits of this technology, mainly decreasing the use of more toxic pesticides in tree crops and forests, will either be lost or traded for other environmental hazards.     

含GFP-Lac Z基因的伪狂犬病病毒上海株缺失株的构建

在伪狂犬病病毒(PRV)上海株gI和gE基因克隆鉴定的基础上，用BamHⅠ BstpⅠ去掉gE基因的5′端363bp，在缺失位置插入绿色荧光蛋白(GFP)和Lac Z基因，构建含双报告基因的PRV-SH转移载体pgEI-GFPZ。将psEI-GFPZ转染PRV-SH的BHK-21细胞，待出现80％病变后收获病毒，并以蚀斑法得到纯化的含Lac Z和GFP两种筛选标记的缺失了gE／gI的重组病毒株。     

几种病毒抑制剂控制烟草花叶病的试验效果

烟草花叶病(烟草普通花叶病TMV,烟草黄瓜花叶病CMV)是陕西烟区烟叶生产中危害最大的病害,发病烟田不仅造成产量的损失,而且使烟叶质量严重下降.近年来在陕西烟区常年流行发生,平均发病率为15%左右,重病田块达到100%,部分烟田绝收,为此作者对目前生产上应用的几种病毒抑制剂进行了田间药效对比试验.     

Identification of an amplified, highly expressed gene in a human glioma

A gene, termed gli, was identified that is amplified more than 50-fold in a malignant glioma. The gene is expressed at high levels in the original tumor and its derived cell line and is located at chromosome 12 position (q13 to q14.3). The gli gene is a member of a select group of cellular genes that are genetically altered in primary human tumors.     

Emergence of novel color vision in mice engineered to express a human cone photopigment

Changes in the genes encoding sensory receptor proteins are an essential step in the evolution of new sensory capacities. In primates, trichromatic color vision evolved after changes in X chromosome-linked photopigment genes. To model this process, we studied knock-in mice that expressed a human long-wavelength-sensitive (L) cone photopigment in the form of an X-linked polymorphism. Behavioral tests demonstrated that heterozygous females, whose retinas contained both native mouse pigments and human L pigment, showed enhanced long-wavelength sensitivity and acquired a new capacity for chromatic discrimination. An inherent plasticity in the mammalian visual system thus permits the emergence of a new dimension of sensory experience based solely on gene-driven changes in receptor organization.     

利用反义基因沉默策略构建水稻突变体库及突变体筛选

尝试利用鸟枪反义基因沉默策略构建水稻突变体库．利用水稻反义cDNA文库转化粳稻品种中花11,获得了来源于105块潮霉素(Hm)抗性愈伤组织的1486个转化植株．随机选择来源于11个独立转化系的335个T0植株进行Hm离体叶片筛选,结果表明所有植株均呈抗性,并且与PER检测结果相吻合,说明T0植株中不存在假转化体．Southern blot分析结果表明T0植株大部分为单位点整合．T0及T1代转化植株均呈现了一些形态变异,如矮化、无分蘖或多分蘖、结实率降低、粒型或穗型改变、小穗结构改变等．利用Hm离体叶片筛选法对部分T1群体进行筛选,得到了1个变异性状与Hm抗性共分离的突变体,该突变体的变异表型为结实率比非转化对照下降约50％,每穗颖花总数比对照减少约40％,二者的总效应导致突变体单穗产量比对照约下降70％．     

Functional delivery of a cytosolic tRNA into mutant mitochondria of human cells

Many maternally inherited and incurable neuromyopathies are caused by mutations in mitochondrial (mt) transfer RNA (tRNA) genes. Kinetoplastid protozoa, including Leishmania, have evolved specialized systems for importing nucleus-encoded tRNAs into mitochondria. We found that the Leishmania RNA import complex (RIC) could enter human cells by a caveolin-1-dependent pathway, where it induced import of endogenous cytosolic tRNAs, including tRNA(Lys), and restored mitochondrial function in a cybrid harboring a mutant mt tRNA(Lys) (MT-TK) gene. The use of protein complexes to modulate mitochondrial function may help in the management of such genetic disorders.