蔗糖浓度对胡萝卜体细胞胚生长与发育的影响

在胡萝卜体细胞胚的悬浮培养中，研究了不同蔗糖浓度对胡萝卜体细胞胚的诱导，生长与发育的影响，５％蔗糖对体细胞胚的诱导具有明显的抑制作用，并对球形胚的发育具有明显的影响。用５％蔗糖的培养基培养含球形胚的悬浮培养物，得到了静止状态的胡萝卜体细胞胚。这种胚经脱水至含水量２３％后于室温干燥４个月，植株转换率为６７％。     

半日花体细胞胚胎发生过程中超氧物歧化酶(SOD)活性的变化

采用萌发几天的半日花 (Helianthemum,songoricum)为外植体 ,以 MS为基本培养基 ,附加不同激素浓度 ,诱导子叶和胚根形成愈伤组织。选生长良好的愈伤组织转入分化培养基中诱导胚状体发生。通过对胚状体发生过程的观察 ,进行 SOD酶活力的测定 ,得出生长旺盛的愈伤组织、体细胞胚等SOD活力变化不同 ,并存在一定的相关性     

四合木体细胞胚胎发生过程中酯酶同工酶的活性变化

采用萌发 1 5天的四合木 ( Terraena mongolica Maxim.)为外植体 ,以 MS为基本培养基 ,附加不同激素浓度 ,诱导子叶和胚根形成愈伤组织。选生长良好的愈伤组织转入分化培养基诱导体细胞胚胎发生。通过体细胞胚胎发生过程的观察 ,进行酯酶同工酶的测定 ,得出生长旺盛的愈伤组织的培养基 ,体细胞胚胎等过程中酯酶同工梅变化不同     

除虫菊愈伤组织诱导及叶的解剖结构研究

本试验分别以除虫菊3个生长阶段的花蕾作为外植体,采用MS+1.0ml/L 2.4-D+0.5 ml/L KT+30.0g/L蔗糖培养基诱导除虫菊愈伤组织,结果发现,以半开放阶段的花蕾诱导愈伤组织,诱导率最高,超过50%,而以未开放阶段的花蕾诱导愈伤组织,其诱导率在30%左右,接近全开放阶段的花蕾其诱导率低于5%;同时采用常规石蜡切片法对除虫菊的愈伤组织进行解剖观察,观察到愈伤组织中有大量胚性细胞、非胚性细胞、管状分子、厚壁细胞等,其中胚性细胞明显区别于非胚性细胞,除虫菊愈伤组织体细胞胚为单细胞起源,在愈伤组织内部和愈伤组织表层都能发生。     

菌核侧耳、平菇原生质体融合条件研究初探

实验以菌核侧耳和平菇作为亲本菌株,液体培养菌丝5d,酶解法破壁制备亲本菌株原生质体,采用电融合方法融合双亲原生质体。结果表明,菌核侧耳和平菇原生质体较为理想的融合条件为：成串脉冲电压30V,成串脉冲频率2MHz,融合脉冲电压400V,脉冲宽度40us,咏冲个数3。再生培养基上涂布再生培养获得8个融合菌株,其中具备双亲性状的菌株为3个。     

人工种子前景诱人

“一粒种子就能改变一个世界”。“谁掌握了种子,谁就控制了世界”。正当各地纷纷选育种子、“种子大战”硝烟正浓的时候,科学家又把研究的目光瞄准了“人工种子”,并展示了诱人的前景。“人工种子”,又称合成种子、超级种子,是指将植物离体培养产生的体细胞胚或其类似物,经过有机化合物的包埋而形成的一种类似于天然植物种子结构的颗粒体。它由三部分组成,即体细胞胚(或其     

离体培养技术在小麦品种改良中的应用进展

本文综述了离体培养技术－幼胚培养、成熟胚培养、幼穗培养、花药和花粉培养、原生质体培养以及离体培养技术与基因工程结合在小麦种质资源创造、新品种选育等方面的应用进展，并探讨了离体培养技术在小麦品种改良中存在的问题和应用前景。     

盐地碱蓬胚性愈伤组织培养及原生质体制备

本实验首先在MS基本培养基上培养盐地碱蓬(SuaedaSalsa(L.)Pall.)的无菌苗,然后用上述无菌苗茎段为外植体在MS1培养基上诱导培养,初始愈伤组织为深黄色、非松脆型,愈伤组织诱导频率为95.64%以上.在继代培养基MS2上继代数月后得到了生长旺盛、疏松、呈乳白色的愈伤组织,用不同组成浓度的酶解液酶解松散型愈伤组织,进一步分离、提纯制备出具有活力的原生质体.以愈伤组织为材料制备原生质体的最适酶解液浓度为10g/L纤维素酶 5g/L离析酶 0.6mol/L甘露醇 0.05mol/L CaCl2.2H2O 0.1%MES.最适酶解时间为12-16h.     

黑僵菌var.majus原生质体的再生回复

研究了黑僵菌ｖａｒ．ｍａｊｕｓ原生质体的性状和再生回复。黑僵菌ｖａｒ．ｍａｊｕｓ原生质体的无核率为２５．３％,有核率为７４．７％,其中单核率为５３．６％,原生质体再生回复的形态可观察到三种,从再生频率和菌落生长发育速度这两方面综合考虑,选择以０．７ｍｏｌ／Ｌ葡萄糖作为原生质体再生回复用培养基的渗透压稳定剂较为合适。     

克隆大熊猫取得阶段性成果

大熊猫供核体细胞在兔卵胞质中可去分化而支持早期重构胚发育 (克隆大熊猫研究第一阶段 ) ,该项目首先得到中国科学院的支持 ,后来国家科技部给予立项。异种克隆大熊猫是要重点解决异种克隆中的难题 ,从而带动有关基础科研工作。克隆大熊猫研究是继第一只体细胞克隆绵羊“多莉”在英国诞生后提出来的。体细胞克隆表明 ,已经高度分化的哺乳动物体细胞可以在去核 (去除染色体 )的卵母细胞中去分化并恢复全能性。体细胞克隆可以把某一个体的遗传物质完整地传递下去 ,因而它对于保存并传播优良个体或者珍稀濒危动物的基因组具有重大意义。体细胞…     

6-磷酸山梨醇脱氢酶基因转化水稻(Oryza sativa L.)研究

以水稻品种秀水11的幼胚为外植体，对影响愈伤组织诱导及植株再生的因素进行了研究。结果表明：MS＋2，4－D 2mg/L作培养基，愈伤组织诱导率达100％，愈伤组织在MS＋6－BA 2mg/L NAA 0.1mg/L的培养基上，分化频率高达75．3％；在此基础上利用基因枪转化技术，将外源的6－磷酸山梨醇脱氢酶基因（gutD)导入水稻基因组，转基因植株表现出对NaCl较强的耐性。     

西藏砂生槐的生物学特性及综合利用

砂生槐(Sophora moorcrofiana)是藏南河各地带分布极广的一种多年生豆科灌木,具有极强的抗旱、耐瘠、抗风沙等生态适应性。目前当地群众挖其植株作为生活燃料,嫩枝叶或干叶为牲畜放牧和越冬饲料.破坏相当严重。为充分开发其利用价值,首次取其不同时期嫩枝叶和种子进行营养成份分析,发现其富含蛋白质16.82—30.60％;脂肪1.60—9.39％;17种氨基酸含量达16.13—24.53％;除色氨酸未能测定外,其余7种必须氨基酸含量均高于箭舌豌豆(Vicia Sativa)、青稞(highland barley)、小麦(Triticum aestivum)和豆科牧草紫花苜宿(Midicum aestivum);热值13461—21029kJ/kg,具有较高的饲用或食用开发价值。     

Development and fertility studies on post-bio-electrosprayed Drosophila melanogaster embryos

Bio-electrosprays (BESs) provide a means of precisely manipulating cells and thus have the potential for many clinical uses such as the generation of artificial tissues∕organs. Previously we tested the biological safety of this technology with a variety of living cells and also embryos from the vertebrate model organisms Danio rerio (zebrafish) and Xenopus tropicalis (frog). However, the viability and fertility of the treated embryos could not be fully assessed due to animal licensing laws. Here we assay the viability and fertility of Drosophila melanogaster (fruit fly) embryos in conjunction with the bio-electrospray procedure. Bio-electrosprayed Drosophila embryos developed into fully fertile adult flies that were indistinguishable from wild-type. Thus, we demonstrate that the bio-electrospray procedure does not induce genetic or physical damage that significantly affects the development or fertility of a multicellular organism. This study along with our previous investigations demonstrates the potential of this approach to be developed for the precise manipulation of sensitive biological materials.     

Microwells support high-resolution time-lapse imaging and development of preimplanted mouse embryos

A vital aspect affecting the success rate of in vitro fertilization is the culture environment of the embryo. However, what is not yet comprehensively understood is the affect the biochemical, physical, and genetic requirements have over the dynamic development of human or mouse preimplantation embryos. The conventional microdrop technique often cultures embryos in groups, which limits the investigation of the microenvironment of embryos. We report an open microwell platform, which enables micropipette manipulation and culture of embryos in defined sub-microliter volumes without valves. The fluidic environment of each microwell is secluded from others by layering oil on top, allowing for non-invasive, high-resolution time-lapse microscopy, and data collection from each individual embryo without confounding factors. We have successfully cultured mouse embryos from the two-cell stage to completely hatched blastocysts inside microwells with an 89% success rate (n = 64), which is comparable to the success rate of the contemporary practice. Development timings of mouse embryos that developed into blastocysts are statistically different to those of embryos that failed to form blastocysts (p–value < 10⁻¹⁰, two-tailed Student''s t-test) and are robust indicators of the competence of the embryo to form a blastocyst in vitro with 94% sensitivity and 100% specificity. Embryos at the cleavage- or blastocyst-stage following the normal development timings were selected and transferred to the uteri of surrogate female mice. Fifteen of twenty-two (68%) blastocysts and four of ten (40%) embryos successfully developed into normal baby mice following embryo transfer. This microwell platform, which supports the development of preimplanted embryos and is low-cost, easy to fabricate and operate, we believe, opens opportunities for a wide range of applications in reproductive medicine and cell biology.     

New rationale for large metazoan embryo manipulations on chip-based devices

The lack of technologies that combine automated manipulation, sorting, as well as immobilization of single metazoan embryos remains the key obstacle to high-throughput organism-based ecotoxicological analysis and drug screening routines. Noticeably, the major obstacle hampering the automated trapping and arraying of millimetre-sized embryos on chip-based devices is their substantial size and mass, which lead to rapid gravitational-induced sedimentation and strong inertial forces. In this work, we present a comprehensive mechanistic and design rationale for manipulation and passive trapping of individual zebrafish embryos using only hydrodynamic forces. We provide evidence that by employing innovative design features, highly efficient hydrodynamic positioning of large embryos on a chip can be achieved. We also show how computational fluid dynamics-guided design and the Lagrangian particle tracking modeling can be used to optimize the chip performance. Importantly, we show that rapid prototyping and medium scale fabrication of miniaturized devices can be greatly accelerated by combining high-speed laser prototyping with replica moulding in poly(dimethylsiloxane) instead of conventional photolithography techniques. Our work establishes a new paradigm for chip-based manipulation of large multicellular organisms with diameters well above 1 mm and masses often exceeding 1 mg. Passive docking of large embryos is an attractive alternative to provide high level of automation while alleviating potentially deleterious effects associated with the use of active chip actuation. This greatly expands the capabilities of bioanalyses performed on small model organisms and offers numerous and currently inaccessible laboratory automation advantages.     

木薯抗叶片早衰的基因工程育种

以农杆菌介导的转化方法将一个抗叶片早衰的基因成功地导入木薯基因组 .将成熟培养 1 5天后的胚状体的子叶切碎 ,与农杆菌LBA44 0 4共培养 3天 ,然后转入器官发生培养基 (MS基本培养基附加BAP 1mg/L、IBA 0 .5mg/L)附加 3 0mg/LG41 8进行筛选 .三个星期后出现抗性的愈伤、芽 .将这些抗性芽连同外植体转入茎轴生长培养基促进苗的生长 ,最后转入生根培养基长成植株 .所得抗性株经PCR、Southern分析证实部分植株为转基因株 .     

白皮松后期胚发育的研究

白皮松成熟胚的显著特点是苗端发达，胚苗端的H／D(高度与直径)比率平均为0.83,   有时达0.96，为松柏类植物所罕见。它的苗端可分为四个细胞区：顶端原始细胞、中央母细   胞、周缘组织和肋状分生组织区。在肋状分生组织与下胚轴的髓之间，有一过渡组织区。       从成熟胚的结构来看，松科成熟胚基本上可以分为3种类型：1．子叶特别发达，但下胚轴短; 2．下胚轴与根冠近等长; 3．下胚轴比较发达，白皮松就是这种类型。     

An integrated microfluidic array system for evaluating toxicity and teratogenicity of drugs on embryonic zebrafish developmental dynamics

Seeking potential toxic and side effects for clinically available drugs is considerably beneficial in pharmaceutical safety evaluation. In this article, the authors developed an integrated microfluidic array system for phenotype-based evaluation of toxic and teratogenic potentials of clinical drugs by using zebrafish (Danio rerio) embryos as organism models. The microfluidic chip consists of a concentration gradient generator from upstream and an array of open embryonic culture structures by offering continuous stimulation in gradients and providing guiding, cultivation and exposure to the embryos, respectively. The open culture reservoirs are amenable to long-term embryonic culturing. Gradient test substances were delivered in a continuous or a developmental stage-specific manner, to induce embryos to generate dynamic developmental toxicity and teratogenicity. Developmental toxicity of doxorubicin on zebrafish eggs were quantitatively assessed via heart rate, and teratological effects were characterized by pericardial impairment, tail fin, notochord, and SV-BA distance ∕body length. By scoring the teratogenic severity, we precisely evaluated the time- and dose-dependent damage on the chemical-exposed embryos. The simple and easily operated method presented herein demonstrates that zebrafish embryo-based pharmaceutic assessment could be performed using microfluidic systems and holds a great potential in high-throughput screening for new compounds at single animal resolution.