人干扰素基因植物表达载体的构建及其在人参愈伤组织细胞中的表达

目的：利用组织培养人参愈伤组织细胞表达人干扰素，探讨用植物细胞表达人类基因的可行性。方法：用PCR从pBV889扩增人干扰素α2b（hIFN-α2b）编码基因，将其克隆于pMD18-T载体和pBI121，进而构建植物细胞表达载体pBIFN。用冻融法将pBIFN导入根瘤农杆菌LBA4404，经卡那霉素和利福霉素筛选后利用农杆菌介导的转化法将hIFN-α2b基因导入人参愈伤组织细胞。经G418筛选，形成阳性细胞。用PCR、RT—PCR、Western blot和WISH／VSV系统检测转基因组织。结果：经PCR检测表明hIFN-α2b基因已成功整合到人参愈伤组织细胞基因组中。RT-PCR证明存在hIFN-α2b基因的转录产物。Western blot分析表明转基因人参愈伤组织细胞能有效表达hIFN-α2b蛋白。WISH／VSV系统检测分析表明表达的hIFN-α2b具有生物学活性。结论：本研究利用转基因人参愈伤组织细胞成功地表达了人干扰素，为进一步提高口服干扰素的疗效打下基础。     

卫生部发布《新资源食品管理办法》

<正>卫生部近日发布第56号部令——《新资源食品管理办法》(以下简称"《办法》"),并决定自2007年12月1日起施行。《新资源食品卫生管理办法》和《转基因食品卫生管理办法》同时废止。据悉,卫生部将对已审批的340种新资源食品按新《办法》清理。该《办法》规定,生产、经营或者使用新资源食品的单位或     

乳腺癌MMTV-ErbB-2转基因小鼠模型的培育观察

目的 研究乳腺癌模型MMTV-ErbB-2转基因小鼠的饲养管理及生长发育情况.方法 乳腺癌模型MMTV-ErbB-2转基因小鼠6只(♀3,♀3).模型动物饲养于清洁级饲育室,按AIN级进行饲养管理.记录小鼠的繁育情况、出瘤时间、肿瘤个数、直径、体质量.结果 MMTV-ErbB-2转基因小鼠已成功繁育9代.共产仔鼠420只.MMTV-ErbB-2转基因小鼠中雌鼠在24～46周均长出乳腺癌肿块,单只鼠的乳腺癌肿块数目1～4个,肿块直径3～15 mm.结论 乳腺癌模型MMTV-ErbB-2转基因小鼠已被成功繁育,MMTV-ErbB-2转基因小鼠生长良好,具有较强的繁殖和适应能力.     

转基因食品的安全性评价

随着转基因食品的广泛应用,其安全性问题越来越引起人们的关注,且目前其安全性评价及其检测技术,尚无统一规范的方法.国内外众多学者的动物实验和人群调查研究显示,转基因食品均显示出一定的安全隐患.本文对国内外转基因食品的安全性评价及其检测技术的概况及进展作一综述.     

10月龄APP/PS1双转基因AD小鼠海马超微结构特征的观察

目的:观察APP/PS1双转基因小鼠海马内Aβ沉积的形态特征。方法:以10月龄雄性APP/PS1双转基因小鼠和C57BL/6小鼠为研究对象,采用Aβ免疫组化和透射电镜技术,观察海马部位Aβ的沉积情况及相关的病理特征。结果:在双转基因小鼠海马内存在致密性神经炎性斑块及营养障碍性突起,但脑微血管壁的Aβ沉积不甚明显;营养障碍性突起及神经细胞、微血管内皮细胞、周细胞内存在大量的自噬泡及次级溶酶体,提示该模型存在自噬溶酶体途径功能紊乱。结论:该鼠模拟了AD的老年斑及相关退行性变等病理改变,其中可能伴有细胞多种代谢的变化及血脑屏障功能的变化。从老年斑角度而言,该动物是成功的阿尔茨海默病动物模型,可用于AD的生化、病理研究及新治疗方法的探索。     

CDglyTK融合自杀基因杀伤喉癌Hep-2细胞的体外实验研究

目的：研究融合自杀基因CDglyTK联合前体药物对喉癌Hep-2细胞的杀伤效应。方法：构建质粒表达载体pcDNA3．1（-）CMV．CDglyTK,XhoⅠ／HindⅢ酶切鉴定,测序分析CDglyTK基因序列。电穿孔法将重组质粒转染Hep-2细胞,400mg／LG418筛选14d获得稳定表达CDglyTK基因的Hep-2细胞,RT—PCR及Western-blotting鉴定CDglyTK基因的表达。以转染空白载体pcDNA3．1（-）的Hep-2细胞为对照,MTT法观察5-FC、GCV、5-FC加GCV对表达CDglyTK基因的Hep-2细胞生长的抑制作用。结果：酶切和基因测序分析证明重组质粒含完整的CD及TK基因,RT—PCR从转染细胞总RNA中扩出707bp的预期片段,Western-blotting检测到该基因表达的分子量为59000的蛋白。表达CDglyTK基因的Hep-2细胞在5-FC、GCV、5-FC加GCV干预下生长受到抑制,5-FC与GCV联合有更强的杀伤效应。结论：CDglyTK融合自杀基因可以成为基因治疗喉癌的有效方法。     

Expression of hepatitis B virus X protein in transgenic mice

AIM: To establish a mice model harboring hepatitis B virus x gene (adr subtype) for studying the function of hepatitis B virus X protein, a transactivator of viral and cellular promoter/enhancer elements. METHODS: Expression vector pcDNA3-HBx, containing CMV promoter and hepatitis B virus x gene open reading fragment, was constructed by recombination DNA technique. Hela cells were cultured in DMEM and transfected with pcDNA3-HBx or control pcDNA3 plasmids using FuGENE6 Transfection Reagent. Expression of pcDNA3-HBx vectors in the transfected Hela cells was confirmed by Western blotting. After restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes. The pups were evaluated by multiplex polymerase chain reaction (PCR) at genomic DNA level. The x gene transgenic mice founders were confirmed at protein level by Western blotting, immunohistochemistry and immunogold transmission electron microscopy. RESULTS: Expression vector pcDNA3-HBx was constructed by recombination DNA technique and identified right by restriction endonuclease digestion and DNA direct sequencing. With Western blotting, hepatitis X protein was detected in Hela cells transfected with pcDNA3-HBx plasmids, suggesting pcDNA3-HBx plasmids could express in eukaryotic cells. Following microinjection of coding sequence of pcDNA3-HBx, the embryos were transferred to oviducts of pseudopregnant females. Four pups were born and survived. Two of them were verified to have the HBx gene integrated in their genomic DNA by multiplex PCR assay, and named C57-TgN(HBx)SMMU1 and C57-TgN(HBx)SMMU3 respectively. They expressed 17KD X protein in liver tissue by Western blotting assay. With the immunohistochemistry, X protein was detected mainly in hepatocytes cytoplasm of transgenic mice, which was furthermore confirmed by immunogold transmission electon microscopy. CONCLUSION: We have constructed the expression vector pcDNA3-HBx that can be used to study the function of HBx gene in eukaryotic cells in vitro. We also established HBx gene (adr subtype) transgenic mice named C57-TgN (HBx)SMMU harboring HBx gene in their genome and express X protein in hepatocytes, Which might be a valuable animal system for studying the roles of HBx gene in hepatitis B virus life cycle and development of hepatocellular carcinoma in vivo.     

环球集萃

实施减肥手术可降患癌概率；常食用魏制品易患前列腺癌；缺觉可能致肥胖 睡眠充足利瘦身；转基因胡萝卜可“补钙”；荷兰科学家提出人体抗冻伤据数。     

吃番茄，活得长

你相信吗？人可以活到160岁。美国哈佛医学院基因诊断室wu-bolin提出人类的潜在寿命可达167岁。可是为什么我们一般人的寿命只有七八十岁，减少了一半左右？一方面，氧可以让我们活着，维持生命；另一方面，它会在体内产生大量的“氧自由基”，攻击氧化细胞，让细胞死亡，器官老化，人也越来越衰老……     

转基因食品选择权在您手中

"随着科技的进步,转基因食品已经在不知不觉中进入了我们的日常生活。转基因食品给人们带来的好处是显而易见的,如解决粮食短缺问题、减少农药的使用量、增加食物营养、增加食物种类,等等。然而,为什么人们还对转基因食品"敬而远之"呢?"