Cloning and Expression of a Chitinase Gene from Sanguibacter sp. C4

The chitinase Chi58 is an extracellular chitinase produced by Sanguibacter sp.strain C4. The gene-specific PCR primers were used to detect the presence of the chiA gene in strain C4. A chiA fragment (chiA-F) was amplified from the C4 genomic DNA and was used to blast-search the related sequences from the GenBank dadabase. By alignment and selection of the highly conserved regions of the homologous sequences, two pairs of primers were designed to amplify the open reading frame (ORF) of the chitinase from strain C4 by nested PCR. The results revealed that the Chi58 ORF consisted of 1 692 nucleotides encoding a protein of 563 amino acid residues. The molecular weight of the mature protein was predicted to be 58.544 kDa. The Chi58 ORF was a modular enzyme composed of a signal peptide sequence, a polycystic kidney disease I domain, and a glycosyl hydrolase family 18 domain. The chitinase of C4 exhibited a high level of similarity to the chitinase A of Serratia (88.9%-99.6%) at the amino acid sequence level. The Chi58 gene was cloned into the expression vector pET32a to construct the recombinant plasmid pChi58 and was expressed in E. coli BL-21 (DE3) cells with IPTG induction. The molecular weight of the Trx-Chi58 fusion protein was estimated to be 81.1 kDa by SDS-PAGE.     

Variability and adaptability of Miscanthus species evaluated for energy crop domestication

A growing body of evidence indicates that second‐generation energy crops can play an important role in the development of renewable energy and the mitigation of climate change. However, dedicated energy crops have yet to be domesticated in order to fully realize their productive potential under unfavorable soil and climatic conditions. To explore the possibility of domesticating Miscanthus crops in northern China where marginal and degraded land is abundant, we conducted common garden experiments at multiple locations to evaluate variation and adaptation of three Miscanthus species that are likely to serve as the wild progenitors of the energy crops. A total of 93 populations of Miscanthus sinensis, Miscanthus sacchariflorus, and Miscanthus lutarioriparius were collected across their natural distributional ranges in China and grown in three locations that represent temperate grassland with cold winter, the semiarid Loess Plateau, and relatively warm and wet central China. Evaluated with growth traits such as plant height, tiller number, tiller diameter, and flowering time, the Miscanthus species showed high levels of genetic variation within and between species. There were significant site × population interactions for almost all traits of M. sacchariflorus and M. sinensis, but not M. lutarioriparius. The northern populations of M. sacchariflorus had the highest establishment rates at the most northern site owing to their strong cold tolerance. An endemic species in central China, M. lutarioriparius, produced not only the highest biomass of the three species but also higher biomass at the Loess Plateau than the southern site near its native habitats. These results demonstrated that the wild species harbored a high level of genetic variation underlying traits important for crop establishment and production at sites that are colder and drier than their native habitats. The natural variation and adaptive plasticity found in the Miscanthus species indicated that they could provide valuable resources for the development of second‐generation energy crops.     

烟草种间杂交亲和性

以野生烟草Nicotiana alata、N.rustica、N.repanda、N.stocktonnii与栽培烟草K326、红花大金元、Yun87、Yun97为材料,进行种间正反杂交,研究种间杂交亲和性。田间观察杂交后的坐果情况并统计坐果率,采用显微荧光染色观察授粉后花粉管在雌蕊上的生长情况,并结合杂交后代萌发检测的方法。结果表明：N.rustica、N.repanda、N.stocktonnii与栽培烟草杂交不亲和。N.rustica花粉能够穿过K326花柱,N.repanda和N.stocktonnii花粉在K326柱头上很少萌发生长。N.alata花粉可以穿过K326的花柱,并得到果实,但是萌发实验显示其种子无活力。N.alata作为母本与栽培烟草杂交不亲和。     

丙型肝炎病毒F蛋白缺失对病毒复制及感染性的影响

探索了F蛋白缺失及核心蛋白(Core)二级结构改变对丙型肝炎病毒(HCV)复制和感染性的影响．利用定点突变方法,将J6JFH1的核心基因引进5个终止密码子以中断F蛋白的表达,从而获得F蛋白缺失的病毒复制子J6JFH1/ΔF．体外制备RNA转录体,并电穿孔转染Huh7.5.1细胞,采用免疫荧光、实时荧光定量PCR方法以及病毒感染等方法,观察F蛋白缺失对病毒复制、蛋白质表达及转染细胞上清感染性病毒颗粒产生的影响．在此基础上,构建5个单一突变病毒体,对HCV核心蛋白进行二级结构分析,观察核心蛋白二级结构对HCV复制和翻译的影响．结果显示,转染48 h后,J6JFH1/ΔF与野生型J6JFH1相比,J6JFH1/ΔF转染阳性细胞数明显降低,细胞内HCV RNA 水平降低约95%,J6JFH1/ΔF转染后不同时间点细胞上清中HCV RNA拷贝数和病毒颗粒也明显降低．5个单一突变体不影响核心基因二级结构,病毒在细胞内复制和感染性与野生型水平一致．J6JFH1/ΔF所产生的改变可能是由于5处突变导致核心基因二级结构改变而造成的．结果说明,HCV F蛋白缺失不影响病毒的复制翻译及病毒颗粒的包装释放,核心蛋白二级结构的改变对病毒复制和翻译则产生较大影响．     

重金属在鲫鱼卵巢的富集及对卵细胞的损伤效应

近些年来,随着国民经济的快速发展,环境和生态问题也日益凸显,其中水域环境受重金属的污染亦愈演愈烈,水生动物的生存受到严峻的挑战。在水环境中,各种重金属元素不但在水生动物的皮肤、肌肉、鳃和其他内脏器官中富集,而且在其赖以生息繁衍、绵延种群的     

胁迫诱导植物体细胞胚发生中相关基因及蛋白的研究进展

植物体细胞胚发生是一个复杂的发育过程,体细胞胚发生已成为研究植物胚胎发育过程中生理、生化、分子生物学等方面分子机理的模式系统。胁迫被认为是对体细胞胚的诱导有重要作用的因素。植物生长调节物质如2,4-D、ABA等目前认为是与胚性能力获得有关的胁迫物质。在蛋白和转录水平上对基因表达的分析中已鉴定出一些与体细胞胚发生相关的基因和蛋白。该文主要对近年来国内外有关胁迫诱导体细胞胚发生的相关基因及蛋白的研究进展进行综述。     

由天然叶黄素转化为玉米黄素的工艺参数的研究

本文通过碱催化反应使叶黄素异构化为玉米黄素,并对实验中的主要影响因素进行了优化.实验结果表明,以1,2-丙二醇为溶剂,氢氧化钾为催化剂,1,2-丙二醇/叶黄素(v/m)为20,氢氧化钾/叶黄素为6,反应温度为110℃,反应时间为168 h时,叶黄素转化为玉米黄素的转化率最高,达93％.     

爬沙虫提取液对果蝇繁殖力及寿命的影响

本实验通过研究爬沙虫提取液对果蝇繁殖力及寿命的影响,证实爬沙虫提取液具有增强果蝇的繁殖力和提高雌性果蝇寿命的作用。采用乙醚麻醉法,收集8 h内羽化的成虫,选择个体大小相近的雌雄果蝇,在不同爬沙虫浓度的培养基中培养,统计各组第一子代(first filial generation,F1)果蝇成体的数目及果蝇体重。收集各培养基中果蝇,区分雌雄,在原浓度爬沙虫培养基中培养,每日观察果蝇死亡数,直至全部死亡。结果表明:与对照组比较,各爬沙虫处理组子代果蝇雄体数目均显著增加(P<0.05),2.500%组的子代果蝇雌体数目差异显著(P<0.05)。各爬沙虫处理组刚羽化的果蝇体重极显著高于对照组(P<0.01)。2.500%剂量组果蝇雌体平均寿命极显著增加(P<0.01)。本研究为更好地利用爬沙虫的药用价值提供了参考依据。     

皱弱蛛属及其模式种的雌性新发现(蜘蛛目,弱蛛科)

首次报道了采自中国河北省赞皇县障石岩风景区(九女峰景区)的宽跗皱弱蛛Rhyssoleptoneta latitarsa Tong & Li,2007的雌性标本,并对该种的雄性模式标本进行重描述.标本保存与中国科学院动物研究所.     

新型大豆异黄酮磺酸酯的临床前药物动力学

为寻找新的大豆异黄酮前药,采用建立的生物样品中药物浓度测定的液相色谱法对新型大豆异黄酮染料木素磺酸酯(GBS)进行前药判定以及大鼠体内药物动力学研究,以考察前药中染料木素(GE)的口服相对生物利用度是否改善。在大鼠体内药物代谢实验中,灌胃给予的大鼠血浆中能检测到GE的存在。在临床前药物动力学实验中,该前体药以40mg/kg GE在大鼠体内的动力学过程符合一室模型。GBS中GE的相对口服生物利用度为原药的198.6%。结果表明:相对于原药GE,前药中GE的相对口服生物利用度得到极大地改善。该前药有进一步研究的意义。