兔转基因单细胞克隆株的分离培养及其染色体倍性分析

为检测原代二倍体细胞转基因后单细胞克隆的增殖能力及其染色体倍性稳定性,用脂质体介导的转染方法将质粒DNA pEGFP-C1（带有报告基因GFP和Neo^r）导入体外培养的兔胎儿成纤维细胞中,经G418药物筛选后,分离出73个GFP阳性细胞克隆,最后存活13个（18％）,对其中9个克隆的染色体倍性进行分析,结果只有2个（22％）克隆的染色体倍性正常率在75％以上,分别为80％和75％,其余7个克隆的染色体倍性正常率均在70％以上。这表明,当使用转基因单细胞克隆株作为供核细胞产生克隆动物时,单细胞克隆的增殖代数和染色体倍性的稳定性需要进一步研究提高。     

商陆单细胞平板培养及色素高产细胞株的筛选

研究了细胞悬浮培养时间、培养方法和接种密度对商陆单细胞平板培养植板率的影响,建立了筛选色素高产细胞株的简单实用的方法。结果表明：普通单细胞平板时培养法培养商陆单细胞的植板率很低,而以悬浮培养１４－２１ｄ的单细胞为材料,接种密度为５＊１０＾３／ｍｌ时,进行条件培养和看护培养,植板率达１１．０２％。根据细胞平板培养结果,可在显微镜下直接观察单细胞克隆的颜色,筛选出商陆色素高产细胞株。     

山羊胚胎大脑皮层神经干细胞分离、培养与鉴定

目的 :从山羊胚胎大脑皮层中分离培养并鉴定神经干细胞。方法 :利用NBS培养和单细胞克隆技术在山羊胚胎大脑皮层中分离出具有单细胞克隆能力的细胞 ,并进行培养、传代、分化观察 ,采用免疫组化检测克隆细胞的神经巢蛋白 (Nestin)抗原和分化后特异性成熟神经细胞抗原的表达。结果 :从胚龄 2 4～ 30d的新鲜山羊胚胎大脑皮层中成功分离出神经干细胞 ,该细胞具有连续克隆能力 ,可传代培养 ,表达神经巢蛋白抗原。分化后的细胞表达神经元细胞、胶质细胞和少突胶质细胞的特异性抗原。结论 :山羊胚胎大脑皮层中存在具有自我更新能力和多分化潜能的神经干细胞。     

建立鸡EPGCs单细胞克隆株初探

目的探索鸡EPGCs单细胞克隆建立细胞系的可能性,并对其生物学特性进行鉴定。方法采取19期和28期的鸡EPGCs,体外培养传至第4代的细胞聚合体,用胰酶消化将细胞分散成单细胞悬液,将单个细胞接种至96孔板,每个孔内接种1个细胞,生长出的细胞集落用胶原酶消化传代,细胞化学法和免疫荧光法检测多向分化细胞的表面标志物;常规染色体核型检查。结果接种的288个单细胞中有9个扩增,其中7个传至第2代,2个传至第4代,克隆形成率为3.1%。扩增出的2~4代单细胞克隆能稳定增殖不分化,具有正常二倍性染色体核型、碱性磷酸酶阳性、阶段特异性胚胎抗原(SSEA)-1等特征性细胞表面标志物呈阳性;离体情况下具有形成类胚体和类上皮样细胞的能力。结论建立鸡EPGCs单细胞克隆细胞系是可行的,其生物学特性稳定。     

生产用重组哺乳动物细胞株的克隆筛选方法

克隆筛选是重组细胞株构建过程中的关键步骤。除了早期的克隆环,有限稀释法、半固体培养法、流式细胞术和细胞分选是目前生物制药行业运用最为广泛的克隆筛选方法。该文综述了克隆筛选方法的原理、特点,介绍了促进方法发展的其他技术如单细胞成像和自动化,比较了不同克隆筛选方法的优缺点。针对如何选择合适的克隆筛选方法提出了建议,为从事相关研究与生产领域的科研人员提供帮助。     

高产人参寡糖素培养细胞克隆系的诱变筛选

紫外辐射能显著地降低人参培养细胞单细胞克隆的植板率。当紫外辐射悬浮细胞３０ｓ后,细胞克隆的植林率是对照组的２１．４３％。细胞克隆平板培养６０ｄ,挑取克隆连续转移培养３次,共获得克隆系１２２株。对所有克隆系进行变异分析并经１０代连续继代培养,从中筛选到一株稳定的高产寡糖素克隆系ＰＧＵＡ－０８,而且它的过氧化物酶同工酶谱特征也保持稳定。克隆系ＰＧＵＡ－０８的生长速率为０．５３７ｇＤＷＬ－１ｄ－１,是亲本的１．４６倍,寡糖素含量为１７．１６％ＤＷ,是亲本的１．８１倍,寡糖素产率为２．７６４ｇ／Ｌ,是亲本的２．６２倍。     

粉叶小檗愈伤组织单细胞克隆

以粉叶小檗愈伤组织为材荆,用B5液体培养基进行悬浮培养建立悬浮细胞糸。经3～4次继代培养即可得到悬浮的单细胞。悬浮细胞通过细胞平板克隆(一般B5培养基平板克隆、优化培养基平板克隆和条件培养基平板克隆),经5代连续继代培养观察和薄板层析-分光光度法分析,发现用优化培养基进行平板克隆植板率最高,且克隆最易成功,并且还筛选到一株小檗碱产率高且稳定的克隆CV-57,其平均生手速率为每天14．412mg／L,为原始株系的1．91倍,平均小檗碱含量为干重的2．17％,是原始株系的2．26倍。     

粉叶小檗愈伤组织单细胞克隆

以粉叶小檗愈伤组织为材料 ,用B5液体培养基进行悬浮培养建立悬浮细胞系。经 3～ 4次继代培养即可得到悬浮的单细胞。悬浮细胞通过细胞平板克隆 (一般B5培养基平板克隆 ,优化培养基平板克隆和条件培养基平板克隆 ) ,经 5代连续继代培养观察和薄板层析 -分光光度法分析 ,发现用优化培养基进行平板克隆植板率最高 ,且克隆最易成功 ,并且还筛选到一株小檗碱产率高且稳定的克隆CV 5 7,其平均生长速率为 14 .4 12mg .Fw/L .d ,为原始株系的 1.91倍 ,平均小檗碱含量为 2 .17%干重 ,是原始株系的 2 .2 6倍。     

单细胞技术在干细胞研究中的应用

干细胞是具有自我更新和分化潜能的异质性细胞群体。基于细胞群体水平的干细胞研究不能满足深入认识干细胞生物学本质及实际应用的需要。近年来,单细胞相关技术不断发展和成熟,并正在干细胞基础研究及其相关领域中获得迅速应用。该文以造血干细胞为主要例举,就实验研究中常用的单细胞分离、单细胞克隆分析、单细胞移植、单细胞实时定量PCR及单细胞测序等技术原理及其应用进行综述。     

卵巢癌干细胞对化疗药物耐药的机制探讨

目的:探讨卵巢癌干细胞(OCSC)对化疗药物的抵抗及其机制。方法:采用有限稀释法、单细胞克隆和无血清培养方法从卵巢癌细胞株OVCAR-3细胞中分离培养OCSC。以卡铂和紫杉醇作用于OCSC和亲代OVCAR-3细胞,采用MTT法检测细胞存活率、Annexin V-FITC/PI双染流式细胞术检测细胞凋亡、JC-1染色流式细胞术检测细胞线粒体膜电位(△ψm),比色测定试剂盒检测caspase-3和caspase-8活性。结果:有限稀释法、单细胞克隆和无血清培养能从OVCAR-3细胞中分离培养OCSC。与亲代OVCAR-3细胞比较,卡铂和紫杉醇作用的OCSC的存活率增加、凋亡率下降、△ψm增加、caspase-3和caspase-8活性下降。结论:OCSC通过抑制化疗药物介导的凋亡内源性和外源性通路对化疗药物产生耐药性。     

Embryo rescue inVicia faba andVicia narbonensis

Embryo rescue in twoVicia faba L. cultivars (‘Polycarpe’ and ‘A-107’) and oneV. narbonensis L. population (A-202) was studied under a 22 ± 2°C/ 16 ± 1° day/night temperature regime. Very young ovules (1.0–1.8 mm long) cultured, in-ovule, on five liquid media remained green for a longer period of time on modified B5, modified Murashige and Skoog and modified Beasley and Ting media than on modified Phillips and Collins and modified Bourgin and Nitsch media. However, no embryo growth or embryo germination was observed. In-ovule culture of older ovules, 6 and 8 days forV. narbonensis and 10 and 14 days forV. faba, on modified B5 liquid medium allowed 6-day-oldV. narbonensis and 14-day-oldV. faba embryos to be rescued. Finally, culture of whole pods of the two species resulted in the rescue of even younger embryos. Thus, plantlets were obtained from as young as 4-day-oldV. narbonensis pods and 11-day-oldV. faba pods.     

二十世纪我国植物学家对植物组织培养的贡献

回顾了上一世纪我国植物组织培养的发展。 1934年以来 ,我国的植物组织培养研究一直与国际发展同步进行。我国学者在离体器官发生、茎尖培养、花药培养、子房培养、胚乳培养、原生质体培养和细胞大量培养等分支领域都取得重要进展。本文在引证我国研究者发表的植物组织培养论文的基础上 ,着重评述了那些被国际同行公认的研究成果。此外 ,还介绍了植物组织培养在我国农业和工业上应用的情况     

二十世纪我国植物学家对植物组织培养的贡献

回顾了上一世纪我国植物组织培养的发展.1934年以来,我国的植物组织培养研究一直与国际发展同步进行.我国学者在离体器官发生、茎尖培养、花药培养、子房培养、胚乳培养、原生质体培养和细胞大量培养等分支领域都取得重要进展.本文在引证我国研究者发表的植物组织培养论文的基础上,着重评述了那些被国际同行公认的研究成果.此外,还介绍了植物组织培养在我国农业和工业上应用的情况.     

猪苓、伴生菌及蜜环菌共培养的形态学研究

本文对猪苓、伴生菌及蜜环菌两两共培养及三者共培养进行了宏观形态观察及细胞学水平上的研究。结果表明,猪苓与伴生菌共培养时,在二者之间形成一致密拮抗线,猪苓菌落表面菌丝分化产生大量菌丝束;猪苓与蜜环菌共培养时,猪苓能阻止蜜环菌菌索对其自身的进一步侵袭,互作区中的双方菌丝及菌索均停止生长;蜜环菌与伴生菌共培养时,蜜环菌能穿透整个伴生菌菌落,在伴生菌菌落下方产生大量分枝;三者共培养后,猪苓对蜜环菌的防御能力有所下降,伴生菌对蜜环菌的耐受力有所提高,蜜环菌产生的新分枝均向伴生菌一侧生长,猪苓与伴生菌之间并不形成致密拮抗线,只可见双方菌丝的白色交融区。 猪苓与伴生菌均能在蜜环菌菌索皮层上形成侵入位点。     

Tapping culture-an improved method for cell suspension culture

Summary A new culture vessel was designed for cell suspension culture. A silicone-convered magnet bar fixed by one end to the side wall of the bottle was held horizontally a short distance from the bottom. A standard type magnetic stirrer was used. In contrast to the conventional horizontal movement of “stirring” in cultures the bar moves vertically with a “tapping” motion. This improvement resulted in less cell injury, higher rate of cell proliferation and formation of fewer bubbles than in the conventional type. Nine cell types were simultaneously cultivated in tapping, stirring and stationary culture. All cell types proliferated more luxuriously in tapping cultures than in stirring cultures. Serial cultivation of cells in tapping cultures was also successful. This work was supported in part by the grants for Cancer Research from the Ministry of Education, Science and Culture, Japan.     

荔枝生物技术研究进展（综述）

从荔枝的组织培养、花药培养和原生质体培养方面综述荔枝生物技术的研究概况,并提出该领域存在问题及发展方向。     

Light requirement and photosynthetic cell cultivation – Development of processes for efficient light utilization in photobioreactors

Although the potential of photosyntheticmicroorganisms for production of various metabolitesand in environmental bioremediation is recognized,their practical application has been limited by thedifficulty in supplying light efficiently tophotobioreactors. Various types of photobioreactorwith high illumination to volume ratios have beenproposed, but most are limited by cost, mass transfer,contamination, scale-up or a combination of these.The problem of light supply to photobioreactorscan be solved by developing photosynthetic cellcultivation systems where light is either substitutedor supplemented. Many strains of photosynthetic cellsare capable of heterotrophic growth under darkconditions and their heterotrophic culture can be usedfor efficient production of biomass and somemetabolites. However, light is absolutely required forefficient production of some metabolites. In suchcases, there is a need to supplement the heterotrophicwith photoautotrophic metabolism. Inphotoheterotrophic (mixotrophic) culture, thephotoautotrophic and heterotrophic metabolisms can beexploited for efficient production of usefulmetabolites but it has many problems such as processoptimization in terms of making a balance between thephotoautotrophic and heterotrophic metabolism. Another promising system is the sequentialheterotrophic/ photoautotrophic cultivation system,where the cells are cultivated heterotrophically tohigh concentrations and then passed through aphotobioreactor for accumulation of the desiredmetabolite(s). Furthermore, cyclicphotoautotrophic/heterotrophic cultivation system canbe used to achieve continuous cell growth underday/night cycles. This involves cultivating thecells photoautotrophically using solar light duringthe day and then adding controlled amount of organiccarbon source during the night for heterotrophicgrowth. In this review, these various systems arediscussed with some specific examples.     

Technology for cell cycle research with unstressed steady-state cultures

A culture system for performing cell cycle analyses on cells in undisturbed steady-state populations was designed and tested. In this system, newborn cells are shed continuously from an immobilized, perfused culture rotating about the horizontal axis. As a result of this arrangement, the number of newborn cells released into the effluent medium each generation is identical to the number of cells residing in the immobilized population, indicating that one of the two new daughter cells is shed at each cell division. Thus, the immobilized cells constitute a continuous, steady-state culture because the concentrations, locations and microenvironments of the cells in the culture vessel do not vary with time. In tests with mouse L1210 lymphocytic leukemia cells, about 10⁸ newborn cells were produced per day. This new culture system enables a multiplicity of cell cycle analyses on large numbers of cells assured to be from populations in steady-state growth.

A simple device for planting replicate mammalian cell cultures

Summary The design and use of a unit for planting uniform inocula for replicate cultures are described. Its design permits continuous gassing of suspensions of mammalian cells with humidified CO₂, thus stabilizing the pH (±<0.05 pH unit) of culture media buffered with sodium bicarbonate. The unit can be readily modified to deliver different volumes; identical samples can be dispensed simply and rapidly, with minimal cell damage and chance of microbial contamination. Quantitative data regarding sample uniformity and growth subsequent to planting with this unit are presented.     

A simple device for planting replicate mammalian cell cultures

Summary The design and use of a unit for planting uniform inocula for replicate cultures are described. Its design permits continuous gassing of suspensions of mammalian cells with humidified CO₂, thus stabilizing the pH (±<0.05 pH unit) of culture media buffered with sodium bicarbonate. The unit can be readily modified to deliver different volumes; identical samples can be dispensed simply and rapidly, with minimal cell damage and chance of microbial contamination. Quantitative data regarding sample uniformity and growth subsequent to planting with this unit are presented.