Tetracycline-inducible Expression Systems： New Strategies and Practices in the Transgenic Mouse Modeling

To accurately analyze the function of transgene(s)of interest in transgenic mice,and togenerate credible transgenic animal models for multifarious human diseases to precisely mimic human dis-ease states,it is critical to tightly regulate gene expression in the animals in a conditional manner.The abilityto turn gene expression on or off in the restricted cells or tissues at specific time permits unprecedentedflexibility in dissecting gene functions in health and disease.Pioneering studies in conditional transgene ex-pression have brought about the development of a wide variety of controlled gene expression systems,whichmeet this criterion.Among them,the tetracycline-controlled expression systems(e.g.Tet-off system andTet-on system)have been used extensively in vitro and in vivo.In recent years,some strategies derived fromtetracycline-inducible system alone,as well as the combined use of Tet-based systems and Cre/lox P switch-ing gene expression system,have been newly developed to allow more flexibility for exploring gene functionsin health and disease,and produce credible transgenic animal models for various human diseases.In thisreview these newly developed strategies are discussed.     

Plant metabolomics and metabolic biology

<正>Plants produce a large array of specialized metabolites(natural products)that not only are essential for growth and development,but also play important roles in adaptation to the variable stressful environments.Also,many plant metabolites are essential nutrient elements for humans and serve as natural drugs.However,study of the biosynthesis of natural products is still in its infancy,because more than 90%of plant     

Genetically Modified Pig Models for Human Diseases

Genetically modified animal models are important for understanding the pathogenesis of human disease and developing therapeutic strategies.Although genetically modified mice have been widely used to model human diseases,some of these mouse models do not replicate important disease symptoms or pathology.Pigs are more similar to humans than mice in anatomy,physiology,and genome. Thus,pigs are considered to be better animal models to mimic some human diseases.This review describes genetically modified pigs that have been used to model various diseases including neurological,cardiovascular,and diabetic disorders.We also discuss the development in gene modification technology that can facilitate the generation of transgenic pig models for human diseases.     

作物抗虫基因工程及其安全性

利用基因工程培育抗虫新品种是农作物害虫防治的有效途径.本文综述了来自细菌的Bt基因及来源于植物的蛋白酶抑制剂基因、凝聚素基因、α-淀粉酶抑制剂基因等转基因植物的防治效果,探讨了它们的安全性,并指出了理想杀虫剂应具备的基本特征。 Abstract:Genetically engineered crop resistance to insects and pests offers a method of crop protection.In this review,we focus primarily on those genes with demonstrated effects in transgenic plants,including Bt toxins genes and those derived from plants,such as protease inhibitor genes,alpha-amylase inhibitor genes,lectin genes.The biosafety of insect resistance transgenic crop and the characteristics of and‘ideal' new pesticide are discussed.     

Canada and China working together in the Nature Reserves of Inner Mongolia Autonomous Region

The environment and its natural resources are one of the richest treasures in the world. The lands, forests, lakes and rivers are not only beautiful spaces in the world, but these ecosystems are the basis of life for all the people and creatures who inhabit the earth. As inhabitants of the earth, we all have a responsibility to take care of these important resources-to protect our biological diversity-for ourselves, for future generations and for the many other creatures that we share the world with. Indeed, as stewards of the environment we must ensure that our actions, and those of the people around us, are not harmful or damaging to the earth.     

转基因植物中筛选标记基因的利用及消除

在基因转移过程中,人们常常使用标记基因来筛选转化细胞或组织。常用的筛选标记基因尤其是抗生素抗性基因的使用往往对环境及植物体的生长发育产生不良影响,且影响基因多重转化。为了消除这些弊端,一种全新的发展策略即获取无选择标记的转基因植物应运而生。本文主要综述转基因植物中有关筛选标记基因及其消除方法。 Abstract:Selective marker gene is usually used to select transformed cells or tissue during gene transfer.However,the use of selective marker gene,especially antibiotic-resistant gene,is harmful to environment,plant development and affects multi-transformation.A new strategy that offers a approach for the elimination of those disadvantages caused by the selectable marker gene is developed.We summarized correlative marker genes used in transgenic plants and some methods of its removal.     

Orthobiologics in the treatment of hip disorders

Orthobiologics are biological materials that are intended for the regeneration or healing of bone,cartilage and soft tissues.In this review we discuss the use of orthobiologics for hip disorders providing an update.The orthobiologics included in this article are hyaluronic acid,platelet rich plasma,bone marrow,adipose tissue and expanded mesenchymal stem cells.We explain the concepts and definitions of each orthobiological product,and the literature regarding its use in the hip joint.The paucity of guidelines for the production and characterization of the biological products leads to uneven results across the literature.Each biologic therapy has indications and benefits;however,noteworthy are the characterization of the orthobiologics,the application method and outcome analysis for further improvement of each technique.     

Electron microscopy: essentials for viral structure, morphogenesis and rapid diagnosis

Electron microscopy(EM) should be used in the front line for detection of agents in emergencies and bioterrorism,on accounts of its speed and accuracy.However,the number of EM diagnostic laboratories has decreased considerably and an increasing number of people encounter difficulties with EM results.Therefore,the research on viral structure and morphology has become important in EM diagnostic practice.EM has several technological advantages,and should be a fundamental tool in clinical diagnosis of viruses,particularly when agents are unknown or unsuspected.In this article,we review the historical contribution of EM to virology,and its use in virus differentiation,localization of specific virus antigens,virus-cell interaction,and viral morphogenesis.It is essential that EM investigations are based on clinical and comprehensive pathogenesis data from light or confocal microscopy.Furthermore,avoidance of artifacts or false results is necessary to exploit fully the advantages while minimizing its limitations.     

The conserved ubiquitin-like protein Hub1 plays a critical role in splicing in human cells

Different from canonical ubiquitin-like proteins, Hub1 does not form covalent conjugates with substrates but binds proteins noncovalently. In Socchoromyces cerevisioe, Hub1 associates with spUceosomes and mediates alternative splicing of SRCI, without affecting pre-mRNA splicing generaity. Human Hub1 is highty similar to its yeast homotog, but its cellular function remains largely unexplored. Here, we show that human Hub1 binds to the spliceosomal protein Snu66 as in yeast; however, unlike its 5. cerevisioe homolos, human Hub1 is essential for viability. Prolonged in vivo depletion of human Hub1 leads to various cellular defects, including splicing speckle abnormalities, partial nuclear retention of mRNAs, mitotic catastrophe, and consequently cell death by apoptosis. Early consequences of Hub1 depletion are severe splicing defects, however, only for specific splice sites leading to exon skipping and intron retention. Thus, the ubiquitin-iike protein Hub1 is not a canonlcal spliceosomal factor needed generally for splicing, but rather a modulator of spliceosome performance and facilitator of alternative splicing.