HCV全长NS3基因表达及在抗体检测中的应用

丙型肝炎病毒(HCV)是引起非甲非乙型肝炎的主要病原因子.被HCV感染的病例中,超过50%以上会引起持续性感染、慢性肝炎,最终可能引起肝硬化和肝细胞癌[1].HCV严重威胁人类健康,但目前对丙肝患者尚缺乏有效的治疗手段,因此,严格把好血源关,提高对丙肝患者检出的灵敏度,是阻止丙肝血源传播的有效手段.     

次生栎林蒸腾强度与生态因子的关系

采用多元回归分析和灰色关联分析方法,探讨下蜀次生栎林蒸腾强度与生态因子的相关关系。研究认为用二次工咕次多项式回归方程和指数回归方程拟合更能反映各生态因子在整个生长季中与蒸腾强度关系的性质。影响蒸腾强度的主要生态因子是温度和净辐射;其次是空气相对湿度和土壤热流通量;风速和土壤含水率的影响很小。灰色关联分析与多元回归分析的结论一致。研究结果为进一步阐明次生栎林的结构和功能提供了理论基础。     

不同DNA疫苗联合接种可有效增强免疫效果

造反乙型肝炎（乙肝）病毒核心抗原（ＨＢｃＡｇＡ）、ｅ抗原（ＨＢｅＡｇ）及单纯疱疹病毒ｇＤ抗原（ＨＳＶ－１－ｇＤ）基因为目的基因,进行ＤＮＡ疫苗联合免疫的研究。通过对不同基因片段的表达研究,选择了能在哺乳动物细胞中高效表达乙肝病毒核心抗原、ｅ抗原和单纯疱疹病毒ｇＤ抗原的质粒ＤＮＡ免疫Ｂａｌｂ／ｃ小鼠。结果显示：表达乙肝病毒核心抗原和单纯疱毒ｇＤ抗原的ＤＨＡ疫苗单独免疫,能有效刺激机体产生体液免疫和细     

钙离子对辣根过氧化物酶同工酶C的溶液构象的影响

运用荧光光谱方法研究了脱辅基的辣根过氧化物酶同工酶Ｃ。结果表明：（１）ａｐｏ－ＨＲＰ（Ｃ）与其他“Ｂ”类蛋白质不同,有明显的Ｔｙｒ荧光;（２）低浓度变性剂（〈２ｍｏｌ／Ｌ脲或０．２ｍｏｌ／Ｌ盐酸胍）能增强酶的Ｔｒｐ荧光,但并不改变光谱特性;（３）进一步增加变性剂浓度则使Ｔｒｐ残基暴露于水溶液中,荧光强度略有降低,荧光谱红移;（４）Ｃａ＾２＋络合剂ＥＤＴＡ对色氨酸荧光的影响与低浓度变性剂相同。有意思     

High-Density Genetic Linkage Map Construction and QTL Mapping of Grain Shape and Size in the Wheat Population Yanda1817 × Beinong6

High-density genetic linkage maps are necessary for precisely mapping quantitative trait loci (QTLs) controlling grain shape and size in wheat. By applying the Infinium iSelect 9K SNP assay, we have constructed a high-density genetic linkage map with 269 F ₈ recombinant inbred lines (RILs) developed between a Chinese cornerstone wheat breeding parental line Yanda1817 and a high-yielding line Beinong6. The map contains 2431 SNPs and 128 SSR & EST-SSR markers in a total coverage of 3213.2 cM with an average interval of 1.26 cM per marker. Eighty-eight QTLs for thousand-grain weight (TGW), grain length (GL), grain width (GW) and grain thickness (GT) were detected in nine ecological environments (Beijing, Shijiazhuang and Kaifeng) during five years between 2010–2014 by inclusive composite interval mapping (ICIM) (LOD≥2.5). Among which, 17 QTLs for TGW were mapped on chromosomes 1A, 1B, 2A, 2B, 3A, 3B, 3D, 4A, 4D, 5A, 5B and 6B with phenotypic variations ranging from 2.62% to 12.08%. Four stable QTLs for TGW could be detected in five and seven environments, respectively. Thirty-two QTLs for GL were mapped on chromosomes 1B, 1D, 2A, 2B, 2D, 3B, 3D, 4A, 4B, 4D, 5A, 5B, 6B, 7A and 7B, with phenotypic variations ranging from 2.62% to 44.39%. QGl.cau-2A.2 can be detected in all the environments with the largest phenotypic variations, indicating that it is a major and stable QTL. For GW, 12 QTLs were identified with phenotypic variations range from 3.69% to 12.30%. We found 27 QTLs for GT with phenotypic variations ranged from 2.55% to 36.42%. In particular, QTL QGt.cau-5A.1 with phenotypic variations of 6.82–23.59% was detected in all the nine environments. Moreover, pleiotropic effects were detected for several QTL loci responsible for grain shape and size that could serve as target regions for fine mapping and marker assisted selection in wheat breeding programs.     

低聚磷酸盐对粪产碱杆菌合成热凝胶的影响

粪产碱杆菌合成热凝胶需要消耗大量ATP用于前体物质UDPG的再生,利用3种具有不同高能磷酸键的低聚磷酸盐Na4P2O7(2P)、Na5P3O10(3P)和(NaPO3)6(6P)作为高能磷酸键供体,并取代培养基中的KH2PO4-K2HPO4(1P)而作为磷元素供体,研究其对粪产碱杆菌合成热凝胶的影响。结果表明相对于对照磷元素摩尔含量的单倍和双倍量添加3P和6P能够分别提高热凝胶产量23%和134%,达到15.1g/L和30.0g/L;同时副产物乙酸分别较对照降低了87.5%和77.7%;在以双倍量添加6P后,副产物甲酸的生成也显著降低75.7%。当培养基中不含碳酸钙进行低聚磷酸盐添加实验时,生物量显著降低,热凝胶合成几乎没有,发酵液pH最低降到2.1。以磷元素单倍量和双倍量分别添加3P和6P,并与1P混合发酵时,热凝胶产量变化不大;但是,当发酵液不存在碳酸钙而1P被作为缓冲物质时,以单倍量和双倍量添加6P使得热凝胶产量较对照分别提高60.4%和49.4%,分别达到18.4g/L和16.9g/L。     

RNA Interference-Based Transgenic Maize Resistant to Maize Dwarf Mosaic Virus

Maize dwarf mosaic virus (MDMV) is a widespread pathogenic virus that causes serious loss of yield in maize (Zea mays). RNA interference (RNAi) triggered by hairpin RNA (hpRNA) transcribed from a transgenic inverted-repeat sequence is an effective way to defend against viruses in plants. In this study, an hpRNA expression vector containing a sense arm and an antisense arm of 150 bp separated by an intron of the maize actin gene was constructed to target the P1 protein (protease) gene of MDMV and used to transform Agrobacterium tumefaciens strain EHA105. The transformed Agrobacterium strain was used to transform maize embryonic calli isolated from immature embryos by an improved culture technique. In all, 46 plants were regenerated after stringent hygromycin B selection, and 18 of them were certified to be positive by PCR amplification. Of these positive plants, 13 were grown to produce offspring, and nine were identified by Southern blotting to have the transgene integrated with one or two copies. The resistance of three T₂ lines was evaluated in a field trial of dual MDMV inoculation in two environments and was found to be improved compared with the non-transformed control. The disease indexes of the transgenic plant lines h2, 13, and h1 were not significantly different from the highly resistant control line H9-21. The viral titers of the inoculated plants were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), and the result was in accord with the resistance evaluated in the field trial. The addition of uniconazole S3307 (0.25 mg l⁻¹) and ABT root-promoting powder (0.5 mg l⁻¹) showed a significant improvement of hardening in regenerated plantlets, which were stronger and generated a better fibrous root system than the control. This improvement could facilitate the transgenic operation of maize.     

响应面分析法优化(R)-扁桃酸发酵培养基

采用响应面分析法对Bacillussp.HB20菌株合成(R)-扁桃酸的培养基成分进行优化。首先利用Plackett-Burman试验设计筛选出影响(R)-扁桃酸产率的三个主要因素:麦芽糖、蛋白胨和牛肉膏。在此基础上用最陡爬坡路径逼近最大响应区域,再利用Box-Behnken试验设计及响应面分析法进行回归分析。结果表明,麦芽糖、蛋白胨和牛肉膏浓度与(R)-扁桃酸产率存在显著的相关性,通过求解回归方程得到最佳质量浓度:蛋白胨11.507g/L,牛肉膏6.708g/L,麦芽糖10.907g/L,(R)-扁桃酸产率理论最大值达到66.87%。经模型验证,预测值与验证试验平均值接近,在优化条件下(R)-扁桃酸产率提高了25.87%。