共查询到20条相似文献,搜索用时 140 毫秒
1.
《大众科学.科学研究与实践》2018,(2)
正“没有克隆猴,就很难建立模拟人类疾病的动物模型,人类的医学技术又向前迈了一大步。”2018年1月25日,中国科学院公布,世界上首只体细胞克隆猴“中中”于2017年11月27日诞生,10天(12月5日)后第二只克隆猴“华华”诞生。克隆猴在中国成功了,与人类相近的非人灵长类动物(猕猴)的体细胞克隆一直是一个国际上的技术难题,这一难题甚至花费了从克隆羊“多利”的诞生直至今日的21年的时间!疾病研究、新药测试将大幅提速中科院神经所所长蒲慕明院士表示,克隆猴的成功,将为脑疾病、免疫缺陷、肿瘤、代谢等疾病的机理研 相似文献
2.
韩国科学家2005年5月19日宣布他们利用体细胞核转移技术,用病人的皮肤细胞克隆出了早期胚胎,并成功提取新的胚胎干细胞系,这一成果使人类干细胞研究向“治疗性克隆”迈进了一大步。2005年5月19日美国《科学》(Science)杂志网络版发表了这一成果。 相似文献
3.
哺乳动物体细胞克隆是20世纪末生命科学领域最引人注目的高新技术,该技术在农业、生物学和医药等方面具有广泛的应用前景。近年来克隆技术发展迅速,多种哺乳动物相继克隆成功,但也存在着克隆效率太低、克隆动物表型正常而实质异常等问题。本文在近年来克隆技术研究的基础上,对克隆的概念、研究历史以及克隆的方法、过程进行了综述,展望了克隆的意义及克隆动物的应用前景,分析了目前克隆技术尚存在的问题,并提出了解决这些问题的关键。 相似文献
4.
意大利生殖技术实验室切萨雷·加利领导的研究小组利用成年细胞成功创造了世界上第一匹克隆马。他们采用的是与克隆羊多莉相同的核移植技术 ,用一匹母马的成年体细胞创造了近 85 0个胚胎 ,其中仅 2 2个达到了细胞分裂阶段。在 4匹受孕的母马中 ,只有一匹于 2 0 0 3年 5月 2 8日 相似文献
5.
6.
克隆可谓是当今最时髦、然而也是最危险的词汇。自从1996年英国科学家用成年绵羊体细胞成功克隆出“多莉羊”以来,“克隆牛”、“克隆猪”陆续出现,尽管这些克隆出来的生命体不是在胚胎发育过程中夭折就是刚出生不久便死去,但它们仍然使全世界震惊。客观地说,克隆这一生物工程技术在动物养殖业中有应用前景, 尽管这种前景十分遥远。利用体细胞核克隆动物将大量繁殖优秀的动物个体,而不用担心优秀个体的遗传物质在繁育过程中被其他个体的遗传物质混杂。此外,现在人们能够对染色体上的基因进行定位, 能够用类似外科手术的方法将染色体中的有害… 相似文献
7.
8.
9.
10.
细胞凋亡在着床前胚胎发育过程中发挥着重要作用,胚胎凋亡检测能为获得高质量的体细胞克隆胚胎提供有益信息,进而有助于提高克隆效率.用原位末端标记法对牛的转基因克隆和转基因再克隆囊胚进行了细胞凋亡检测,再克隆囊胚是利用转基因克隆牛的体细胞作为供体细胞进行体细胞核移植后获得的第二代克隆胚胎.结果表明转基因克隆胚胎的囊胚发育率显著低于非转基因克隆胚胎的囊胚发育率,而转基因克隆囊胚的细胞凋亡指数显著高于非转基因克隆胚胎的细胞凋亡指数.此外,转基因再克隆胚胎的囊胚发育率和胚胎细胞凋亡指数与非转基因克隆胚胎的囊胚发育率和胚胎细胞凋亡指数相比差异性不显著.结果表明早期的转基因克隆胚胎发育能力的减弱可能是由于供体细胞的基因转染和药物筛选过程导致的,而再克隆对其早期胚胎的发育能力没有负面影响. 相似文献
11.
本文对传统检测基因组DNA甲基化的亚硫酸氢盐方法进行了修改,使它适用于植入前胚胎的DNA甲基化检测研究,从而能够测定少量细胞的(<500个)DNA甲基化状态.结果,用此法成功检测了牛克隆胚胎X染色体中Xist基因的甲基化情况. 相似文献
12.
运用克隆测序的方法测定了椴树科Tiliaceae、梧桐科Sterculiaceae、杜英科Elaeocarpaceae和大风子科Flacourtiaceae 21种以及外类群蔷薇科4种植物的叶绿体trn L-trn F序列,并结合GenBank中已公布的3科44个代表种的trn L-trn F序列进行系统发育分析。采用最简约法、最大似然法和Bayesian推测分析椴树科、梧桐科和杜英科科间和属内的系统发育关系。结果显示:①文定果属Muntingia构成一个独立于梧桐科和椴树科的分支,具有较高bootstrap的支持率和后验概率,表明建立文定果科Muntingiaceae具有合理性;②滇桐属Craigia与梧桐科翅子树属Pterospermum、肖槿属Thespesia、苹婆属Sterculia、可乐果属Cola、梧桐属Firmiana和银叶树属Heritiera的关系密切。支持将滇桐属归于梧桐科的观点;③杜英属Elaeocarpus和猴欢喜属Sloanea均为杜英科的主要成员,应归于杜英科;④椴树科、梧桐科和杜英科有较近的亲缘关系。特别是,椴树科和梧桐科的关系非常密切,两科并没有构成两个独立的单系群,而是形成复系群。 相似文献
13.
目的比较不同类型体细胞对生产转基因克隆胚胎效率的影响。方法利用脂质体介导的方法将质粒pEGFP-N1转染到五指山小型猪胎儿成纤维细胞和骨髓间充质细胞,经过G418筛选后均获得了阳性细胞株。然后分别以两种类型转基因细胞以及未转基因细胞为核供体进行体细胞核移植,比较不同类型供体细胞克隆胚胎的囊胚发育率。结果胎儿成纤维细胞和骨髓间充质细胞克隆胚的囊胚发育率差异不显著(P>0.05,8.3%vs.7.1%);转基因胎儿成纤维细胞(9.6%)和转基因骨髓间充质细胞(9.9%)克隆胚胎的囊胚发育率差异不显著(P>0.05,9.6%vs.9.9%);每一种类型供体细胞转基因与否对克隆胚的囊胚发育率无影响(P>0.05)。结论通过体细胞核移植技术,小型猪骨髓间充质细胞与胎儿成纤维细胞均可有效地生产转基因囊胚。 相似文献
14.
HIV-1和HBV复合型DNA免疫的初步研究 总被引:1,自引:0,他引:1
近年的研究表明,在啮齿类和非人灵长类免疫带有编码病毒和细菌抗原基因的质粒DNA可以激发体液和细胞免疫应答.在本实验中,将HBV的S基因和HIV-1的gp160基因以融合形式插入到载体pcDNA3中,其能表达HBsAg和gp160的融合蛋白,并将此质粒DNA分别直接注射到Balb/c小鼠和Swis小鼠.三次免疫后,用ELISA的方法初步检测HBsAg和gp160抗原特异的抗体免疫应答均为阳性.结果说明,带有HBV和HIV-1融合基因的质粒DNA直接免疫小鼠后,均激发了小鼠产生相应的免疫应答反应,这个结果为研究和生产多价疫苗提供了新的思路 相似文献
15.
Yi Long Yang Sun Ying Wang XiaoCui Xing Zhuo Zhao ChunHong Wang YunGe Fan HuaiFeng Mi 《科学通报(英文版)》2008,53(17):2617-2623
Here, we introduce a new type of molecular imprinted polymer (MIP) with immobilized assistant recognition polymer chains (ARPCs) to create effective recognition sites and with bacterial cloned protein as template for adsorbing the low content target protein from cell extract. In this work, cloned pig cyclophilin 18 (pCyP18), a peptidyl-prolyl cis/trans-isomerase, was used as template. The template protein was selectively assembled with ARPCs from their library, which consists of numerous limited length polymer chains with randomly distributed recognition sites of positively charged amino groups and immobilizing sites. These assemblies were adsorbed by porous microsphers and immobilized on them. After removing the template, binding sites complementary to the target protein in size, shape and the position of recognition groups were exposed, and their confirmation was preserved by the cross-linked structure. The synthesized MIP was used to adsorb the cellular pCyP18, and its proportional content was enriched more than hundred times. The extended experiment on imprinting bovine serum albumin (BSA) with ARPCs shows that this method is also suitable for large protein. 相似文献
16.
An embryonic pattern of expression of a human fetal globin gene in transgenic mice 总被引:46,自引:0,他引:46
During the evolution of the beta-globin family gene in vertebrates, different globin genes acquired different developmental patterns of expression. In mammals, specific 'embryonic' beta-like globins are synthesized in the earliest erythroid cells, which differentiate in the yolk sac of the embryo. In most mammals the embryonic globin chains are replaced by 'adult' beta-globins in fetal and adult erythrocytes, which arise in the liver and bone marrow, respectively. However, in simian primates (including humans), a distinct 'fetal' type of beta-like globin chain predominates in fetal erythroid cells. Based on the pattern of DNA sequence homologies between different mammalian species, these fetal globin genes, G gamma and A gamma, are thought to have descended from an ancestral gene, 'proto-gamma', which was embryonic in its pattern of expression. In the mouse, as well as in most other mammalian species, the descendants of the proto-gamma gene continue to function as embryonic genes. To investigate the evolutionary changes that led to the 'fetal recruitment' of the gamma-globin genes in primates, we have introduced the cloned human G gamma-globin gene into the mouse germ line. We report here that the human G gamma gene reverts to an embryonic pattern of expression in the developing mouse. This observation suggests that during evolution a shift occurred in the timing of expression of a trans-acting signal controlling the proto-gamma gene. 相似文献
17.
Jaeger JJ Beard KC Chaimanee Y Salem M Benammi M Hlal O Coster P Bilal AA Duringer P Schuster M Valentin X Marandat B Marivaux L Métais E Hammuda O Brunet M 《Nature》2010,467(7319):1095-1098
Reconstructing the early evolutionary history of anthropoid primates is hindered by a lack of consensus on both the timing and biogeography of anthropoid origins. Some prefer an ancient (Cretaceous) origin for anthropoids in Africa or some other Gondwanan landmass, whereas others advocate a more recent (early Cenozoic) origin for anthropoids in Asia, with subsequent dispersal of one or more early anthropoid taxa to Africa. The oldest undoubted African anthropoid primates described so far are three species of the parapithecid Biretia from the late middle Eocene Bir El Ater locality of Algeria and the late Eocene BQ-2 site in the Fayum region of northern Egypt. Here we report the discovery of the oldest known diverse assemblage of African anthropoids from the late middle Eocene Dur At-Talah escarpment in central Libya. The primate assemblage from Dur At-Talah includes diminutive species pertaining to three higher-level anthropoid clades (Afrotarsiidae, Parapithecidae and Oligopithecidae) as well as a small species of the early strepsirhine primate Karanisia. The high taxonomic diversity of anthropoids at Dur At-Talah indicates either a much longer interval of anthropoid evolution in Africa than is currently documented in the fossil record or the nearly synchronous colonization of Africa by multiple anthropoid clades at some time during the middle Eocene epoch. 相似文献
18.
Human urotensin-II is a potent vasoconstrictor and agonist for the orphan receptor GPR14. 总被引:48,自引:0,他引:48
R S Ames H M Sarau J K Chambers R N Willette N V Aiyar A M Romanic C S Louden J J Foley C F Sauermelch R W Coatney Z Ao J Disa S D Holmes J M Stadel J D Martin W S Liu G I Glover S Wilson D E McNulty C E Ellis N A Elshourbagy U Shabon J J Trill D W Hay E H Ohlstein D J Bergsma S A Douglas 《Nature》1999,401(6750):282-286
Urotensin-II (U-II) is a vasoactive 'somatostatin-like' cyclic peptide which was originally isolated from fish spinal cords, and which has recently been cloned from man. Here we describe the identification of an orphan human G-protein-coupled receptor homologous to rat GPR14 and expressed predominantly in cardiovascular tissue, which functions as a U-II receptor. Goby and human U-II bind to recombinant human GPR14 with high affinity, and the binding is functionally coupled to calcium mobilization. Human U-II is found within both vascular and cardiac tissue (including coronary atheroma) and effectively constricts isolated arteries from non-human primates. The potency of vasoconstriction of U-II is an order of magnitude greater than that of endothelin-1, making human U-II the most potent mammalian vasoconstrictor identified so far. In vivo, human U-II markedly increases total peripheral resistance in anaesthetized non-human primates, a response associated with profound cardiac contractile dysfunction. Furthermore, as U-II immunoreactivity is also found within central nervous system and endocrine tissues, it may have additional activities. 相似文献
19.
目的利用微卫星DNA技术对通过体细胞克隆技术获得的两只西农莎能奶山羊进行鉴定。方法提取两只克隆西农莎能奶山羊、两只受体西农莎能奶山羊母羊、西农莎能奶山羊供体细胞和两只对照组西农莎能奶山羊母羊的基因组DNA,通过5对具有显著多态性差异的引物扩增微卫星DNA序列,并对其进行微卫星DNA分析。结果两只克隆西农莎能奶山羊和供体细胞的基因型完全一致,受体母羊和对照组母羊的微卫星DNA多态性则与前两者均不相同。结论两只克隆西农莎能奶山羊基因组DNA来源于供体细胞。 相似文献
20.
The record of early fossil Simiiformes (Anthropoidea) from the Late Eocene and Early Oligocene of Africa and the Arabian Peninsula has increased dramatically in recent years. We report here the discovery of a new, diminutive and much older (Early or Middle Eocene) simian from an Algerian locality, Glib Zegdou. This species is smaller than any other living or fossil African simiiform. Derived similarities shared with Aegyptopithecus suggest that the new genus is more closely related to propliopithecines than to oligopithecines, implying that these two subfamilies differentiated during the Early Eocene. The new discovery confirms predictions about the great antiquity of Simiiformes and emphasizes a long and endemic African history for higher primates. 相似文献