转基因动物应用研究的现状与进展

对转基因动物在提高动物生产性能、异种器官移植和基因治疗方面的研究现状和应用前景进行了较系统全面的概述。提高动物的生产性能包括提高动物的生长速度和产毛性能 ;异种器官移植的机理主要为补体介导的超急排异反应 ,猪是最佳异种器官供体 ;基因治疗在短期内已取得了显著成绩 ,但不是万能的 ;转基因动物在应用方面前景广阔 ,但仍存在一些问题。     

转基因动物在免疫学研究中的应用

转基因动物技术在分子免疫、免疫耐受、自身免疫、移植免疫、抗感染免疫和免疫防治等研究中的应用日益广泛。表达功能性重排的 T细胞抗原受体 (TCR)的转基因动物的应用加深了人们对 TCR基因重排、T细胞在胸腺中的发育过程、αβT细胞和γδT细胞分化途径及 T细胞免疫耐受形成机制的认识 ;免疫分子及其受体转基因动物成为研究其功能的直接手段 ;病毒及病毒受体转基因动物为研究病毒致病机制、抗病毒治疗及疫苗评价提供了新的模型 ;自身免疫病和用于移植免疫研究的转基因动物模型成为探讨疾病发病机制及治疗手段的有力工具。目前利用转基因动物已生产出多种抗体、干扰素、IL-2、TNFα、G-CSF、L F等诊断和治疗性生物活性蛋白     

利用实时荧光定量PCR检测外源基因拷贝数体系的建立

黑素皮质素受体4(Melanocortin receptor 4,MC4R)基因是影响猪生长肥育性能的主效基因之一,是参与调控体重、采食和能量平衡的关键信号物质。动物转基因技术目前主要应用于生产珍贵蛋白、基因治疗、器官移植、动物品种改良和建立疾病模型等方面。目前人们已经获得了如羊、牛、小鼠、猪等多种转基因克隆动物。确定外源基因的拷贝数和整合位点是对后续外源基因功能探讨和表型研究的前提条件。本研究将MC4R基因转入猪PK15细胞中,挑单克隆,通过3对特异性引物对转染细胞做PCR扩增检测出阳性细胞,实时荧光定量PCR检测外源基因拷贝数,初步建立了检测外源基因拷贝数的实验体系。     

鸡输卵管生物反应器的研究进展

随着人们对营养类蛋白、医用类蛋白需求量的增长,建立经济高效的生产技术平台成为转基因动物研究的重要领域,鸡输卵管生物反应器作为转基因鸡重要的应用器官得到越来越多的重视。目前,构建用于携带外源基因的高效表达载体和良好的导入方法是制备能够稳定生产外源基因转基因鸡的关键技术,文章对鸡输卵管生物反应器的研究进展进行了综述,并提出了存在的问题。     

动物胚胎干细胞在动物科学中的应用

自Ｅｖａｎｓ等从延迟着床胚胎中分离出小鼠胚胎干细胞 (ＥＳ)以来 ,包括小鼠在内的各种动物ＥＳ细胞的分离受到国内外科学家的关注[1] 。ＥＳ细胞在克隆动物 ,生产转基因动物 ,创建人类遗传疾病动物模型 ,研究细胞分化 ,细胞与细胞的相互关系以及用人类ＥＳ细胞定向分化制造用于器官移植的组织器官等领域具有广阔的应用前景。本文对动物ＥＳ细胞克隆及其遗传操作技术在动物遗传育种、胚胎学及发育生物学领域的应用前景作一评述和展望。1　生产克隆动物1 1　利用ＥＳ细胞生产克隆动物的优势　近年来的研究表明 ,动物早期胚胎细胞、动物胚胎…     

骨骼肌电穿孔转基因技术研究进展

目前,在大动物模型试验中,骨骼肌电穿孔转基因技术已被广泛用于转染一些功能基因,并能显著提高非病毒载体基因的转染效率。笔者就电穿孔促进基因通过细胞膜的可能机理及影响骨骼肌电穿孔转基因效率的关键因素（如物种、细胞直径、场强、脉冲参数、电极和电脉冲仪等）进行了综述。     

雄性生殖系干细胞的研究进展

睾丸干细胞群移植技术的发展及转基因技术的运用,将为生殖基础科学和家畜及野生动物资源保护、雄性不育治疗、转基因动物生产、基因治疗等提供一条新的途径。本文主要介绍了雄性生殖系干细胞的研究进展,其中包含睾丸内主要细胞之间相互调控的作用以及各种细胞分离培养建系和应用,精原干细胞移植的生物学研究模式,移植进雄性体内精原干细胞如何产生能分化成精子的子代细胞。     

转基因动物应用研究的现状与进展

对转基因动物在提高动物生产性能、异种器官移植和基因治疗方面的研究现状和应用前景进行了较系统全面的概述。提高动物的生产性能包括动物的生长速度和产毛性能：异种器官移植的机理主要为补体介导的超急排异反应,猪是最佳异器官供体;承短期内已取得了显著成绩,但不是万能的;转基因动物在应用方面前景广阔,但仍存在一些问题。     

慢病毒载体及慢病毒介导的RNA干扰

慢病毒载体是高效的基因转导工具,能将外源基因序列稳定导入分裂期细胞和非分裂期细胞.将慢病毒载体与RNA干扰结合能在哺乳动物的各类细胞中特异性抑制同源基因的表达,它将是基因功能研究和基因治疗的有力手段.应用慢病毒栽体进行转基因动物的制备,转基因的效率将得到显著提高.慢病毒介导的RNA干扰具有高效、稳定、特异性强的特点,它能在哺乳动物的各类细胞、多种疾病的离体细胞中实现稳定的RNA干扰.该技术被广泛用于基因功能的研究,在疾病的基因治疗上也具有良好的前景.     

慢病毒载体及慢病毒介导的RNA干扰

慢病毒载体是高效的基因转导工具,能将外源基因序列稳定导入分裂期细胞和非分裂期细胞.将慢病毒载体与RNA干扰结合能在哺乳动物的各类细胞中特异性抑制同源基因的表达,它将是基因功能研究和基因治疗的有力手段.应用慢病毒载体进行转基因动物的制备,转基因的效率将得到显著提高.慢病毒介导的RNA干扰具有高效、稳定、特异性强的特点,它能在哺乳动物的各类细胞、多种疾病的离体细胞中实现稳定的RNA干扰.该技术被广泛用于基因功能的研究,在疾病的基因治疗上也具有良好的前景.     

A brief overview of transgenic farm animals

Transgenesis offers new possibilities to rapidly modify the genome of living organisms. The application of transgenesis to farm animals faces many problems, more than those observed in the transgenesis of laboratory animals, as there are currently many different techniques available to obtain transgenic animals, which all have problems regarding low efficiency and high costs. When these techniques are applied to farm animals the problems concerning transgenesis are multiplied. Two main techniques, male pronuclear microinjection and sperm mediated gene transfer, utilised in farm animal transgenesis, are briefly presented. The improvement of these techniques and the employment of other biotechnologies such as cloning, could expand the uses of transgenic farm animals for human health.     

Use of Transgenic Animals to Improve Human Health and Animal Production

Contents Transgenic animals are more widely used for various purposes. Applications of animal transgenesis may be divided into three major categories: (i) to obtain information on gene function and regulation as well as on human diseases, (ii) to obtain high value products (recombinant pharmaceutical proteins and xeno-organs for humans) to be used for human therapy, and (iii) to improve animal products for human consumption. All these applications are directly or not related to human health. Animal transgenesis started in 1980. Important improvement of the methods has been made and are still being achieved to reduce cost as well as killing of animals and to improve the relevance of the models. This includes gene transfer and design of reliable vectors for transgene expression. This review describes the state of the art of animal transgenesis from a technical point of view. It also reports some of the applications in the medical field based on the use of transgenic animal models. The advance in the generation of pigs to be used as the source of organs for patients and in the preparation of pharmaceutical proteins from milk and other possible biological fluids from transgenic animals is described. The projects in course aiming at improving animal production by transgenesis are also depicted. Some the specific biosafety and bioethical problems raised by the different applications of transgenesis, including consumption of transgenic animal products are discussed.     

转基因在动物生产中的应用

人们一直期望畜产品和人类健康产品能快速得到提高,DNA重组技术和转基因的出现使得在不同物种间,甚至不同系统发育领域间的这一提高在很大范围内变为可能。如今,我们能在细菌中生产人类胰岛素,在牛奶中获得人类凝结因子。转基因、动物克隆和动物多产技术的进步在一定程度上已经实现了在动物转基因领域的期望。作者回顾了当前动物转基因乳、肉和转基因抗病动物的研究近况,并讨论了一些由转基因技术应用而引发的生物伦理学和商业性问题。     

Transgenesis may affect farm animal welfare: a case for systematic risk assessment

This paper considers (potentially) harmful consequences of transgenesis for farm animal welfare and examines the strategy of studying health and welfare of transgenic farm animals. Evidence is discussed showing that treatments imposed in the context of farm animal transgenesis are by no means biologically neutral and may compromise animal health and welfare. Factors posing a risk for the welfare of transgenic farm animals include integration of a transgene within an endogenous gene with possible loss of host gene function (insertional mutations), inappropriate transgene expression and exposure of the host to biologically active transgene-derived proteins, and in vitro reproductive technologies employed in the process of generating transgenic farm animals that may result in an increased incidence of difficult parturition and fetal and neonatal losses and the development of unusually large or otherwise abnormal offspring (large offspring syndrome). Critical components of a scheme for evaluating welfare of transgenic farm animals are identified, related to specific characteristics of transgenic animals and to factors that may interact with the effects of transgenesis. The feasibility of an evaluation of welfare of transgenic farm animals in practice is addressed against the background of the objectives and conditions of three successive stages in a long-term transgenic program. Concrete steps with regard to breeding and testing of transgenic farm animals are presented, considering three technologies to generate transgenic founders: microinjection, electroporation and nuclear transfer, and gene targeting including gene knockout. The proposed steps allow for unbiased estimations of the essential treatment effects, including hemi- and homozygous transgene effects as well as effects of in vitro reproductive technologies. It is suggested that the implementation of appropriate breeding and testing procedures should be accompanied by the use of a comprehensive welfare protocol, specifying which parameters to monitor, at which stages of the life of a farm animal, and in how many animals. Some prerequisites and ideas for such a protocol are given. It is anticipated that systematic research into the welfare of farm animals involved in transgenesis will facilitate the use of the safest experimental protocols as well as the selection and propagation of the healthiest animals and, thereby, enable technological progress that could be ethically justified.     

mRNA技术及其在动物疫病研究中的应用进展

mRNA技术是一种将人工合成的mRNA分子引入细胞内，并利用细胞自身的翻译机制将其翻译成蛋白质的技术。作为一种新兴的生物技术，mRNA技术已经在疫苗研究、基因治疗等多个领域取得了重要进展，并在新冠预防和传染病防治方面进行了临床应用，展现出了广阔的应用前景。通过对mRNA技术的发展历程，mRNA疫苗的设计、递送及特点，以及其在动物疫病研究的进展予以综述，分析其存在的问题，展望今后的发展方向，为相关研究提供参考。     

New Biotechniques and their Consequences for Farm Animal Welfare

Contents This paper considers (potentially) harmful consequences of new biotechnologies for farm animal welfare. The most important new biotechnologies that are currently used in farm animals breeding and husbandry include: multiple ovulation and embryo transfer (MOET) and in vitro embryo production (IVP). Cloning by nuclear transfer (NT) and transgenesis are still in development and mainly applied for experimental purposes with the prospect of a more widespread practical implemention in the future. Evidence is presented showing that generally accepted technologies such as MOET and IVP, relative to in vivo procedures, can result in a host of deleterious side-effects commonly known as the large offspring syndrome (LOS). Likewise, NT and transgenesis, which also typically include several in vitro reproductive manipulations, have clearly been associated with the occurrence of LOS symptoms. It is argued that transgenesis may constitute one additional set of factors that may negatively affect farm animal welfare: the expression of the transgene and the concomitant synthesis and release of a protein. NT might lead to incompletely reprogramming of the transferred genome. It is suggested that the introduction of new biotechnologies into farm animal husbandry should be accompanied by scientifically valid and systematic studies into the effects on animal welfare, with the help of a comprehensive welfare protocol.     

转基因山羊研究进展

近年来,动物转基因技术发展日淅完善,在牛、羊、猪等家畜上的应用日益增多.为全面了解山羊转基因技术的研究进展,论文简要回顾了国内外转基因山羊生产的里程碑事件,总结了生产转基因山羊的方法和原理,并对转基因山羊研究状况、应用前景及存在问题进行了较为系统的概括和分析,从而为借助现代生物技术丰富我国山羊育种手段,加快山羊新良种培...     

昆虫转座子及在家蚕中的应用

概述了近年来广泛应用于昆虫的若干转座子及其基本构造和应用;着重讨论了piggyBac转座子的构造和转座机制及所作成的转基因昆虫种类及标记基因:同时列举了在家蚕转基因中的实例.     

基因治疗中的非病毒型载体研究进展

基因治疗载体一般分为病毒性载体和非病毒性载体。由于病毒型载体存在安全性问题,目前非病毒性载体的研究越来越受到人们的重视。非病毒载体是新兴的基因转导系统,具有低毒、低免疫反应、外源基因整合几率低、无基因插入片断大小限制,以及使用简单、制备方便、便于保存和检验等优势。脂质体作为常用的非病毒性载体容易制备,安全性高,却难达到质控要求,体内基因导入效率低,且无靶向性,使得其应用受到限制。pH一敏脂质体、阳离子脂质体等大大提高了脂质体的转运效率。同时高分子载体、纳米基因转运体在基因治疗中的应用,也为非病毒载体在临床上的应用开辟了广阔的前景。     

影响猪精子介导基因转移效果的因素研究

为优化猪精子载体法技术参数,利用荧光定量PCR、荧光显微镜检测和精液常规检测方法,分析不同DNA转染剂、不同孵育温度和不同形态DNA对猪精子转染外源DNA的影响。结果表明,PEI和TransFast转染剂能极显著提高猪精子转染效果,且PEI优于TransFast,而NanoFect转染剂包裹DNA不能转染精子。随着转染温度的升高,精子的活力和活率均明显下降,而转染率和内化外源DNA量基本保持稳定,而吸附外源DNA量呈下降趋势。环状DNA和线性化DNA在与精子共孵育后,两者的精子活力、活率、转染率和内化外源DNA量差异均不显著,精子吸附线性化DNA量极显著高于环状DNA量。综合分析表明,外源DNA形态对猪精子转染效果无显著影响;PEI和TransFast能够显著提高猪精子转染效果;共孵育温度以17℃为最佳,本结果为开展精子载体法制备转基因猪研究提供了基础试验依据。