共查询到18条相似文献，搜索用时 198 毫秒
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动物克隆的机理及其潜在问题 总被引：1，自引：0，他引：1
目前动物克隆技术因应用低效和后代生长发育异常等缺陷而受到限制,问题的根源在于对动物克隆机理缺乏了解。文章对此进行了简要阐述,其中包括细胞周期、线粒体命运、X染色体失活以及供体核的基因组再程序化,并对克隆技术潜在的问题做出了说明。 相似文献
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在不同的外界因素下,使用胞质内体细胞核注射的方法,为进一步提高猪体细胞核移植的效率来寻找新途径。利用屠宰场卵巢采集的卵母细胞经过去核,注核及激活等操作后,研究猪颗粒细胞和胎儿成纤维细胞,血清饥饿处理法及不同的激活时间等因素对猪核移植重构胚体外发育的影响.结果表明,猪颗粒细胞和胎儿成纤维细胞用作核供体与猪卵母细胞构建重构胚,在卵裂率上无显著性差异。作为供核细胞的猪成纤维细胞,经过血清饥饿与不经过血清饥饿培养,核移植重构胚的卵裂率无显著性差异。在进行核注射后,使供核细胞与胞质受体作用适当的时间(1～6h)在进行激活,有利于重构胚的发育。提示颗粒细胞和猪胎儿成纤维细胞用作核供体与猪卵母细胞构建重构胚以及作为供核细胞的猪成纤维细胞,经过血清饥饿与不经过血清饥饿培养处理后,这二者对猪核移植重构胚发育的均无明显影响。但是使供核细胞与胞质受体作经过适当的时间(1～6h)的激活,却有利于重构胚的发育。 相似文献
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克隆技术与克隆动物的产生 总被引：1，自引：0，他引：1
20世纪末，克隆"多莉"羊的问世，给动物遗传改良方法带来重大的变革，受到了人们的极大关注。克隆技术更成为人们最热门的话题，开创了生物世界的新世元。
克隆(Clone)源于希腊文Klon，原意为用树木的枝条增殖。现指人工诱导下的无性繁殖，即从一个细胞得到两个以上的细胞，细胞群或生物体，由一个亲本系列产生的DNA系列的技术，称之为克隆技术。将一个细胞分裂繁殖一大群细胞，叫一个克隆。。1903年开始将克隆引入园艺学，随后逐渐应用到植物学、动物学和医学方面，现已通过无性繁殖方式产生后代，如克隆青蛙、克隆鼠、克隆兔、克隆猴、克隆猪、克隆牛，乃至用体细胞克隆山绵羊。这在动物生产中将是一次革命性的飞跃。这一尖端生物技术的出现，它还能挽救那些濒危动物。故国际科学界将克隆技术列为20世纪重大的科技成果之一。将标志新世纪克隆时代的到来。 相似文献
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动物胚胎干细胞的建立与应用 总被引：1，自引：0，他引：1
胚胎干细胞(Embryonic stem cells,ES细胞)是从早期胚胎内细胞团(inner cell mass ICM)或原始生殖细胞(Primordial germ cells,PGCs)经体外分化抑制培养分离克隆的。本文介绍了胚胎干细胞的概念,对ES细胞分离、培养和鉴定方法及在动物遗传育种中的应用进行了综述。 相似文献
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转基因动物技术的研究进展 总被引：1，自引：0，他引：1
转基因动物是现代生物技术中一个举足轻重的研究领域,目前已有转基因小鼠、猪、牛、鱼、鸡等多种转基因动物问世。文章论述了转基因动物技术的原理、技术方法,以及转基因动物应用的领域,如生产药用蛋白、抗病育种,作为器官移植供体等,同时也指出了转基因动物存在的不足,展望了其发展前景。 相似文献
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为研究Ⅱ型草鱼呼肠孤病毒外纤维蛋白VP56与宿主蛋白的相互作用,实验采用酵母双杂交Gal4系统鉴定与VP56相互作用的草鱼蛋白。首先利用RT-PCR技术从Ⅱ型GCRV感染的草鱼肾细胞中扩增目的基因VP56,构建p GBKT7-VP56诱饵表达载体;在酵母菌株中检测其自激活性后,以VP56为诱饵在草鱼酵母双杂交文库中筛选阳性菌株,并对阳性克隆的序列进行分析。实验也克隆了草鱼JAM-A(Gc JAM-A)基因,并构建p GADT7-Gc JAM-A载体,在酵母中研究草鱼Gc JAM-A与病毒蛋白VP56相互作用的可能性。研究表明构建的诱饵质粒p GBKT7-VP56无自激活作用,可以应用于酵母双杂交筛选;从草鱼肾细胞文库中筛选得到9株阳性克隆,基因测序及序列分析确定其中包含草鱼7个细胞内蛋白和1个细胞外基质蛋白;VP56蛋白与Gc JAM-A蛋白在酵母中不能发生相互作用。本研究初步确定了与Ⅱ型GCRV蛋白VP56存在潜在相互作用的宿主蛋白,为深入探讨VP56蛋白在Ⅱ型GCRV感染宿主过程中的生物学功能奠定了基础。 相似文献
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磷元素是动物体内含量较多的矿物元素之一，其需要量仅次于钙，在动物生长发育中占有重要地位。其中占总磷的85％～88％的磷存在于骨骼和牙齿中，与钙一起维持骨骼和牙齿的正常硬度，其余在细胞外液和细胞中分布，参与动物体内几乎所有的分解和合成代谢；在能量储存、释放和转换中起着极为重要的作用；是保证动物骨骼正常生长发育、最优繁殖性能和最佳生长效率所必需的营养元素。 相似文献
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为了保存濒危鱼类中华鲟种质资源,对其囊胚细胞和原肠细胞进行了冷冻保存和核移植试验。用二甲亚砜(DMSO)、1,2-丙二醇(PG)、羟乙基淀粉(HES)3种抗冻剂,配制4种冷冻保护液:CP1(12%D)、CP2(10%P)、CP3(8%D 6%E)、CP4(7%P 6%E),冷冻细胞存活率分别为47.4%±4.7%、64.4%±3.6%、54.7%±4.7%、76.7%±5.7%,CP4保存效果最好,说明添加非渗透型抗冻剂羟乙基淀粉能提高冷冻保存细胞的存活率。比较了两种冷冻方法,发现细胞在-7℃平衡30min之后直接投入液氮的一步冷冻降温法是可行的。对不同发育时期的胚胎细胞冷冻存活率进行了比较,结果表明原肠细胞冷冻存活率(64.4%±11.8%)明显比囊胚细胞的(57.1%±11.2%)高(P<0.05)。用冷冻复苏后的囊胚细胞和原肠细胞作供体,以中华鲟未受精卵作受体进行核移植,各移植了469和392枚卵,分别获得了5尾和2尾克隆鱼,核移植成功率分别为1.1%和0.5%。表明可通过冷冻保存胚胎细胞结合核移植技术保存鱼类种质资源。 相似文献
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《水生生物资源》2003,16(4):395-398
The commercial culture of several important species of fish has long been associated with productivity problems generally attributable to fertilisation rates, hatching rates, and embryonic development. Our present knowledge of the molecular processes accompanying fertilisation in fish is scant at best. Here, we examine how new findings about the molecular mechanisms underlying reproduction in other animal groups may help advance our understanding of how egg activation takes place in fish. A better understanding of egg activation in fish is likely to make a highly valuable contribution to future growth of the aquaculture industry. 相似文献
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Determination of primary structure of amberjack myosin heavy chain and its relationship with structural stability of various fish myosin rods 总被引：1，自引：0，他引：1
Reina Kawabata Nobuyuki Kanzawa Masahiro Ogawa Takahide Tsuchiya 《Fish physiology and biochemistry》2000,23(4):283-294
The structural stability of fish myosin depends upon species and temperatures of water in which fish live. Primary, secondary, and quaternary structures of myosin heavy chain (MyHC) from three species of fish living at different temperature ranges have been compared with those of rabbit MyHC in order to investigate the differences in stability. Primary structure of MyHC, although being accessible for warm-water and cold-water fish (carp and walleye pollack), was not available in previous for tropical-water fish literature; so in this study primary structure of MyHC of the tropical-water fish amberjack has been determined by cloning and sequencing its cDNA. The MyHC has 1938 amino acid residues (AA), which are almost as much as as those of carp and walleye pollack. The amberjack MyHC is 91–95% homologous with other fish and rabbit MyHCs. There is a discernible difference between animal species with stable myosin rod (amberjack, carp, and rabbit) and walleye pollack with unstable rod. Stable rod species have a high probability of forming coiled-coil around the COOH-terminal end of the rod, while the pollack has a low coiled-coil formation probability. In addition, the average scores of the coiled-coil for myosin rod were rabbit (1.738) > amberjack (1.691) > carp (1.680) > walleye pollack (1.674) which correlated exactly with the observed stability. The results suggest that coiled-coil forming ability, particularly around the COOH-terminal end, directs structural stability of fish myosin rod. 相似文献
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Embryonic stem cells in fish: current status and perspectives 总被引：5，自引：0，他引：5
Totipotent embryonic stem (ES) cells represent a bridge that links in vitro and in vivo manipulations of animal genomes and have enormous potential for genetic engineering of livestock. We have recently established feeder cell-free conditions for culturing cells of midblastula embryos (MBE) of the medaka (Oryzias latipes) and obtained several stable cell lines that show all features of mouse ES cells in vitro. One of these lines, MES1, has been demonstrated to retain a diploid karyotype and can be induced to differentiate into various cell types in vitro. Upon microinjection into albino host blastulae, MES1 cells are able to form pigmented chimeras. Genotype-specific PCR analysis revealed that 90% of host blastulae transplanted with MES1 cells developed into chimeric fry. This high frequency was not compromised by cryostorage or DNA transfection of the donor cells. Transplantation of genetically labelled MES1 cells revealed a wide contribution to numerous organs derived from all three germ layers and differentiation into various types of functional cells. These ES properties of MES1 line was not abolished by stable gene transfer and long-term selection. Thus MES1 cells may represent a first promising cellular vehicle for the production of genetically modified fish. The genetic background has been found to have a profound effect on the efficacy of ES cell derivation and of chimera formation. 相似文献
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利用Cytodex 3微载体悬浮培养系统规模化培养大鲵肌肉细胞(GSM)和大鲵虹彩病毒(GSIV),研究了微载体培养GSM细胞的形态和增殖特性,同时测定了病毒在培养系统中的增殖动态相关指标。结果显示,在Cytodex 3微载体培养系统中,将GSM细胞在贴壁期以转速30 r/min,每静置40 min搅拌2 min的方式间歇搅拌,10 h后贴壁率可达95%,培养基中最适血清浓度为10%,最适微载体浓度为2 g/L,最适细胞初始接种密度为1.2×10~5 cells/mL;增殖期以25 r/min的连续搅拌方式可以达到最佳的细胞生长效能。倒置显微镜与扫描电镜观察结果显示,GSM细胞呈长梭形,紧密贴附在Cytodex 3微载体上,生长良好。采用优化的工艺条件培养GSM细胞,以感染复数(MOI)为0.5的剂量接种GSIV至规模化培养的GSM细胞,48 h后GSM细胞出现典型的细胞病变效应,72 h病毒滴度达到最高TCID_(50)=10~(–8.50±0.20)/mL。本研究为大鲵虹彩病毒病疫苗的规模化生产工艺研究奠定了前期基础。 相似文献
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RNA干扰(RNAi)是由双链RNA(dsRNA)诱发的特异性沉默目的基因表达的过程,一种大规模制备双链RNA的方法可以便利RNAi技术的应用。以斑节对虾kazal型蛋白激酶抑制剂(KPI)基因为例,详细介绍了一种以体内载体表达大量制备dsRNA(>300nt)的方法。使用商业载体pGEMT和pDRIVE,以2步克隆法构建含有发夹环(hairpin loop)dsRNA表达载体,转化RNA酶Ⅲ缺陷的大肠杆菌HT115(DE3)进行体内转录制备dsRNA。构建的发夹RNA表达载体含有494bp的正向靶序列和403bp的反向互补靶序列,其中正向靶序列多出的91bp即可成为loop环,而无需再次克隆加入。培养30mL的细菌,即可得到1mg纯化的dsRNA,而其成本仅为使用商业化体外转录试剂盒的四分之一。为评估RNAi效果,按照每1克虾体肌肉注射2μg dsRNA的剂量,在dsRNA注射后0,6,12和24h采集血淋巴,RT-PCR检测KPI mRNA的基因转录水平。与对照组GFP-dsRNA和NaCl注射组相比,KPI-dsRNA注射组可以在24h内沉默血淋巴中的KPI基因。结果表明该方法是可大规模制备长的dsRN... 相似文献
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Carp, Cyprinus carpio L., spermatozoa swelling in NaCl hypotonic solutions (18.8, 37.5, 75, 100 mM) was studied by the methods of photometry and resistance impulses spectroscopy (RIS). The possibility of application of the value of relative optical density of cell suspension, as a qualitative characteristics of the extent of spermatozoa swelling in the period of their movement, was demonstrated. It has been noted, that the moment when swelling starts coincides with the moment of the start of sperm motility. Movement duration, extent and time of swelling depend on the osmotic pressure of the activation solution and moreover the maximum motile period is observed during the activation by 75 mM NaCl solution. 相似文献
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SUMMARY: Adenocarcinomatous growths comprising glandular cavities surrounded by cuboidal to low columnar cells and a large amount of mucus produced by the mucous cells, were observed in the the gastric lymph nodes of a harbor seal Phoca largha. The seal was stranded on the coast of Toyama Bay, Sea of Japan, on 2 March, 1998. Necroscopic examination also showed the animal had significant signet ring cell carcinoma in the stomach, as has been reported elsewhere. The adenocarcinoma may have developed from metastatic cells arising in the gastric carcinoma. 相似文献
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