转基因鱼的研究进展

转于的外源基因构建需要有妄动仓,目的基因和终止子等,常用外源基因的导入方法有显微注射,电穿孔等,并介绍了外源基因表达模式及常用的标记基因。转基因鱼的研究比较落后,当务之急是从分子水平上分析鱼类的生理现象及表达基因的结构。     

Optimization of Electroporation Parameters for Immature Embryos of indica Rice(Oryza sativa)

To obtain a suitable condition for electroporation transformation in indica rice.the 10-day-old immature embryos were selected for optimization experiments.The results showed that one pulse at 850 V/cm,950 μF capacitance,200 μL electreporation buffer with 70 mmol/L sodium glutamate,100 μg/mL plasmid,50 pg/mL carrier DNA,20 embryos per cuvette,0°C treatment and CC medium were the best parameters,which not only jmprovecl the transformation efficiency to 30.89%,but also ameliorated the embryo survival ratio to 95.92%.To further verify the practicability of this condition,the embryes from another indica rice variety and a rice type Ⅱ metallothionein-like gene(OsMT2bL)promoter::mgfp5::gusA construct were tested,and specific GUS expression on the embryos was visualized by histochemical staining.The results showed that the GUS expression on the embryos activated by the OsMT2bL promoter was mainly concentrated on the apical point of the plumule whereas the expression driven by CaMV35S promoter was distributed on nearly all areas of the electroporated tissues.These results indicated that the optimized embryo electroporation conditions could be used not only in genetic transformation of indica rice but also in assay of gene regulation on embryos.     

Application of New Electrical Technologies Therapy in Treatment of Cancer

Because of its high efficiency in restraining tumor, being easy in parameter controlling and no remnants toxicity , the use of electrical technologies in cancer therapy has gotten quite great progress in only more than 20 years. The effects of different electrical stimulate methods to the malignancy tissue from different angles are introduced. These electrical stimulate methods change the living environment of malignancy tissue to help or direct treat cancer.     

大珠母贝基因转移的电击参数

将大珠母贝精子经不同脉冲循环数、脉冲数和不同脉冲幅度处理后，与卵子受精，然后观察受精和发育情况并进行统计分析，根据受精率确定最佳参数组合为：脉冲循环数6、脉冲数2^8和脉冲幅度6KV。此前用电击参数为脉冲循环数6、脉冲数2^7和脉冲幅度10KV进行了大珠母贝转基因实验，获得转基因阳性贝。     

Prolongation of survival of dogs with oral malignant melanoma treated by en bloc surgical resection and adjuvant CSPG4‐antigen electrovaccination

Reported post‐surgery 1‐year survival rate for oral canine malignant melanoma (cMM) is around 30%; novel treatments are needed as the role of adjuvant chemotherapy is unclear. This prospective study regards adjuvant electrovaccination with human chondroitin sulfate proteoglycan‐4 (hCSPG4)‐encoded plasmid in 23 dogs with resected II/III‐staged CSPG4‐positive oral cMM compared with 19 dogs with resected only II/III‐staged CSPG4‐positive oral cMM. Vaccination resulted in 6‐, 12‐, 18‐ and 24‐month survival rate of 95.6, 73.9, 47.8 and 30.4%, respectively [median survival time (MST) 684 days, range 78–1694, 8 of 23 dogs alive] and 6‐, 12‐, 18‐ and 24‐month disease‐free interval (DFI) rate of 82.6, 47.8, 26.1 and 17.4%, respectively (DFI 477 days, range 50–1694). Non‐vaccinated dogs showed 6‐, 12‐, 18‐ and 24‐month survival rate of 63.2, 26.3, 15.8 and 5.3%, respectively (MST 200 days, range 75–1507, 1 of 19 dogs alive) and 6‐, 12‐, 18‐ and 24‐month DFI rate of 52.6, 26.3, 10.5 and 5.3%, respectively (DFI 180 days, range 38–1250). Overall survival and DFI of vaccinated dogs was longer in those <20 kg. In vaccinated and non‐vaccinated dogs local recurrence rate was 34.8 and 42%, respectively while lung metastatic rate was 39 and 79%, respectively.     

罗伊乳酸杆菌高效电转化方法的建立

【目的】建立野生型罗伊乳酸杆菌的高效电转化方法,为乳酸杆菌工程菌的研究提供参考。【方法】采用醋酸锂(LiAc)和二硫苏糖醇(DTT)对不同浓度(0.5×109,1.0×109,2.5×109,5.0×109,10.0×109 mL-1)的罗伊乳酸杆菌分别预处理0,10,20,30min,制备罗伊乳酸杆菌感受态细胞,用于电转化,采用PCR和EcoRⅠ酶切鉴定阳性转化子,建立罗伊乳酸杆菌高效电转化方法。【结果】罗伊乳酸杆菌转化效率随LiAc和DTT处理时间的延长和细胞密度的升高而提高,在本试验条件下罗伊乳酸杆菌电转化的最佳菌体浓度为10.0×109 mL-1,LiAc和DTT的最佳处理时间为20min,在该条件下转化效率达(32.60±7.12)×107 cfu/μg,比未经LiAc和DTT处理的细胞转化效率高104倍以上。【结论】建立了罗伊乳酸杆菌高效电转化方法,电转化的最佳菌体浓度为10.0×109 mL-1,LiAc和DTT的最佳处理时间为20min。     

大载体转染猪胎儿成纤维细胞的电转条件优化

背景 随着生物技术发展,研究的生理机制和生物功能日益复杂,提高大载体的转染效率对多基因共表达系统、基因编辑技术、转基因育种等具有重要的意义。在转基因育种中,使用的转基因载体相对较大,而且转基因动物的制备效率也与供体细胞猪胎儿成纤维（porcine Fetal Fibroblasts,PFFs）细胞的转染效率有关。目的 研究主要从转染参数、质粒用量和拓扑结构三方面,比较3种电转仪ECM ^?830/NEPA 21/Nucleofector ^TM2b的大载体转染效率,以探索大载体转染PFFs的最佳条件。方法 使用3种不同电转仪将长达26 kb的携带增强型绿荧光蛋白基因的pPXAT-EGFP质粒转染1×10 ⁶个PFFs,48 h后使用流式细胞仪测定荧光细胞比例,从电转参数、质粒用量和拓扑结构三方面分别比较瞬时转染效率。结果 首先比较电转仪不同参数的转染效率,结果显示当电转参数为脉冲电压300 V,脉冲长度1 ms,脉冲间隔50 ms,脉冲次数3次,NEPA 21转染PFFs的效率最高,为13.24%±1.63%,而Nucleofector ^TM 2b的最佳电转参数为U-023,其转染效率高达46.36%±3.95%。然后在最佳电转参数下分别比较6、8、10和12 μg的26 kb超螺旋质粒的转染效率,ECM ^?830和Nucleofector ^TM 2b转染PFFs的最佳质粒用量为12 μg,其转染效率分别为8.44%±0.90%（电转参数：脉冲电压300 V,脉冲长度1 ms,脉冲次数3 次）和14.63%±3.21%(电转参数：U-023),而NEPA 21使用10 μg质粒转染PFFs时效率达到最高（6.09%±0.72%）。最后比较不同质粒拓扑结构的转染效率,结果显示线性化质粒的转染效率较低,仅为超螺旋质粒转染效率的34.96%—48.39%。结论 因此Nucleofector ^TM 2b转染PFFs的最佳条件为：U-023程序、12 μg超螺旋质粒;NEPA 21为：脉冲电压200 V,脉冲长度3 ms,脉冲间隔50 ms,脉冲次数3次、10 μg超螺旋质粒;ECM ^?830则在脉冲电压300 V,脉冲长度1 ms,脉冲次数3 次条件下转染12 μg超螺旋质粒可获得最佳转染效率。综合比较上述3种电转仪,26 kb大载体转染PFFs的最佳电转仪是Nucleofector ^TM 2b。     

表达绿色荧光蛋白重组乳酸杆菌的构建及电击转化条件

应用DNA重组技术构建了表达绿色荧光蛋白(GFP)的重组乳酸杆菌．将pGFP2质粒中的绿色荧光蛋白基因切下,克隆进表达载体质粒pThioHisB的NcoⅠ和SacⅠ位点之间,构建成重组表达质粒pThaioGFP,然后转化大肠杆菌B121．从BL21中提取重组质粒,用电击法转化乳酸杆菌Lac1001,当细菌处于D600nm为0．6的生长期时,使用PEB作为电击缓冲液,对100μL体积的细胞悬液在电容25μF,电阻200Ω,电压2．2kV的电击条件进行完整质粒转化可得到较高的转化率．电击转化后Lacl001于LB培养基上呈绿色,在荧光透射仪下观察,整个菌体发绿色荧光．构建的重组乳酸杆菌能够稳定表达绿色荧光蛋白．