Genetic Engineering Approaches to Pig Production*

Modern biotechnology promises a number of new applications in animal breeding and production. Although conventional pig breeding has achieved a high level of efficiency and productivity numerous problems have been encountered with animal health and the loss of meat quality. Selection based on phenotypic performance data of individual animals does not take into account the importance of specific genes and their relevance within a complex regulatory system. In most cases it is therefore difficult to trace back the genetic origins of clinically important disorders. The application of genetic engineering techniques in pig production will facilitate diagnosis, improvement of productivity, and animal health by allowing direct genetic manipulation. Attention must be focussed on the physical and genetic analysis of the procine genome. The isolation and characterisation of genes, DNA-markers, polymorphic DNA-fragments, and their chromosomal assignment will be important prerequisites and tools for the elucidation of genetic disorders. Especially the detection of heterozygous carriers of recessive disorders and their elimination from the breeding stock will increase selection accuracy and decrease the generation intervals. But also the rapid and simple detection of infectious diseases, which is sometimes difficult if not impossible at present, will improve animal health and welfare. Although the production of transgenic animals either by DNA-microinjection into zygotes or the use of embryonal stem cells manipulated in vitro is less straightforward than DNA-based diagnosis it will play an important role in the direct manipulation of the porcine genome and genes. Breeding programmes including the use of transgenic livestock have already been developed. There is no doubt that genetic engineering has reached a degree of practical feasibility, allowing it to play an important role in pig breeding in particular and animal production in general.     

水稻耐盐转基因及分子标记的研究进展

回顾水稻耐盐性研究的历史;概述水稻的渗透调节物质如脯氨酸、海藻糖、甜菜碱、糖醇类等对盐胁迫的生理反应及转基因研究;介绍分子标记在水稻耐盐育种上的应用。     

转基因抗虫彩色棉对棉蚜抗性的初步鉴定

将已获得的抗棉铃虫、蚜虫转基因 (Bt GNA)彩色棉纯合品 (株 )系进行了棉蚜抗性评价 ,包括罩笼接蚜试验和田间自然感蚜。结果表明 ,在天彩科技园 ,罩笼内抗虫转基因彩色棉蚜害指数减退率分别比受体对照品种减少 2 1 7%～ 30 43%,蚜体变小 ,蚜重减轻 ;罩笼外有蚜株率和卷叶株率比对照略有下降 ,蚜害指数减退率在 - 1 4 2 9%～ 5 4 1 6%之间。在卡尔墩彩色棉试验基地 ,在罩笼内抗虫转基因彩色棉蚜害指数减退率为 - 33 33%～ 5 8 34%;罩笼外有蚜株率和卷叶株率比对照略有下降 ,蚜害指数减退率在 - 2 7 76%～ 40 0 0 %之间。不同品种间棉蚜抗性有差异。     

Expression profiling of transgenes (Cry1Ac and Cry2A) in cotton genotypes under different genetic backgrounds

Transgenic cotton carrying the CrylAc gene has revolutionized insect pest control since its adoption,although the development of resistance in insect pests has reduced its efficacy.After 10 years of cultivating Bacillus thuringiensis(Bt) cotton with a single Cry1 Ac gene,growers are on the verge of adopting Bt cotton that carries the double gene(Cry1 Ac+Cry2 A) due to its better effectiveness against insect pests.Thus,the current study was designed to evaluate the role of each gene in the effect...     

转基因技术在畜牧兽医中的发展前景

通过简要叙述转基因动物研究的发展简史、研究现状和存在问题 ,对转基因动物育种、药物生物反应器、组织器官移植 ,以及基因治疗和免疫等前景进行了综述。在此基础上 ,从畜牧兽医角度出发提出了追踪发展趋势的几点思考。     

狂犬病病毒糖蛋白转基因小鼠的构建研究

将狂犬病病毒糖蛋白ｃＤＮＡ ＢｇｌⅡ（１．６７ｋｂ）片段正向插入ｐＭＴ０１０／Ａ＾＋ＢａｍＨⅠ切点，构建重组质粒ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ，用ＥｃｏＲⅠ＋ＳａｌⅠ对ｐＭＴ０１０／Ａ＾＋－Ｒｇｐ进行双酶切后，回收含有狂犬病病毒糖蛋白ｃＤＮＡ和绵羊ＭＴ启动子的２．７６ｋｂ片段，通过显微注射技术将该片段注入小鼠单细胞受精卵雄前核内，在进行胚胎移植后，获得４４只小鼠，经ＰＣＲ、Ｓｏｕｔｈｅｒｎ杂交及原位     

精子载体法获得转人her2基因猪

将带有外源基因的载体酶切纯化后与去精清的猪新鲜精液按比例混合，17℃静置处理使外源DNA进入精子头部，通过人工授精使受体母猪怀孕后产下20头仔猪，经PCR特异性片段扩增，特异片段序列测定和比对，共4头PCR结果为阳性。初步证明人her2基因已在猪染色体上整合，其整合率约为20％。本研究利用精子载体法成功获得了转基因阳性猪，为大动物的转基因研究提供了理论与实践的参考。     

转基因技术的发展与应用对养蜂业的影响

经过几十年的发展,转基因作物已逐步从实验室研究阶段走向大面积的生产应用,转基因作物及其产品的安全性则一直是人们争论的焦点。转基因技术的发展与应用与养蜂业密切相关。虽然转基因蜜蜂的生产应用为时尚早,但转基因作物的大量种植,给蜜蜂的安全带来了隐患,也使得蜂产品中可能掺入转基因成分。及时评估转基因植物对蜜蜂的影响不仅有助于保护养蜂业,也有助于减轻甚至避免由转基因植物带来的生态风险。欧盟和日本对转基因作物及其产品的谨慎态度,使得转基因食品的安全性成为一个新的贸易壁垒。我国养蜂业应尽早应对,研究完善涉及转基因植物的蜂产品生产制度及建立相应的检测标准。     

人乳铁蛋白转基因小鼠杂交选育的研究

根据孟德尔遗传原理,对表达人乳铁蛋白转基因小鼠进行近交和远交,获得了纯合子小鼠(P品系1♀、Q品系1♀1♂)和双重杂合子小鼠(PQ杂合3♀3♂).催乳获得小鼠乳汁,ELISA检测乳汁中人乳铁蛋白的含量.通过比较发现,纯合子小鼠和单纯杂合子小鼠在表达量上没有明显差异,而双重杂合子小鼠的表达量则较前两者有明显提高.     

转基因植物疫苗研究进展

众多研究表明,病毒的抗原决定簇及细菌毒素亚单位均能在转基因植物中成功表达,并保持良好的免疫原性.与现有的疫苗生产体系相比,植物生产疫苗具有安全、经济、稳定、高效等优势.本文概述了利用不同受体植物生产疫苗的研究现状、免疫原性评价及免疫原基因的优化表达策略.