Comparison of transformation efficiency of piggyBac transposon among three different silkworm Bombyx mori Strains

The transformation rate of three different strains of silkworm Bombyx mori was comparedafter the introduction of enhanced green fluorescence protein (EGFP)-encoding genes into the silkwormeggs by microinjection of a mixture of piggyBac vector and helper plasmid containing a transposase-encodingsequence.Although there were no significant differences among the three strains in the percentages offertile moths in microinjected eggs (P=0.1258),the percentages of G_0 transformed moths in fertile mothsand injected eggs were both significantly different (P=0.01368 and P=0.02398, respectively).Thetransformation rate of the Nistari strain (Indian strain) was significantly higher than that of the other twostrains,Golden-yellow-cocoon (Vietnamese strain) and Jiaqiu (Chinese strain),which had similar rate. Theseresults indicate that the transformation efficiency of the piggyBac-based system might vary with silkwormstrains with different genetic backgrounds.The presence of endogenous piggyBac-like elements might bean important factor influencing the transformation efficiency of introduced piggyBac-derived vectors,andthe diverse amount and activation in different silkworm strains might account for the significant differences.     

Reproduction diversity of Enteromorpha prolifera

Enteromorpha prolifera (Muell.) J. Agardh (Chlorophyta, Ulvophyceae), which is distributed widely in the Inter-tidal zone of the ocean, is one of the most common fouling green algae. However, the present understandings of the life history of E. prolifera have been insufficient to explain their seasonal abundances. Thus it is essential to investigate how many.reproductive strategies are likely to contribute to the successful colonization and flourishing of the green alga. In the present study the reproduction diversity of E. prolifera was observed and studied systematically by culturing chopped tissues. Our results showed that there are in total seven pathways of reproduction for E. prolifera including sexual, asexual and vegetative reproduction. It was Indicated that the variety of the reproductive ways and the large quantity of reproductive cells produced and released during the reproductive season are the two key factors that facilitate colonization of E. prolifera. The reproduction of the alga E. prolifera mainly depends on asexual methods. The results presented here contribute to increasing our understanding about how the opportunistic macroalgae successfully maintain colonization and excessive growth.     

Observations on the division characterization of diploid nuclear in <Emphasis Type="Italic">Porphyra</Emphasis> (Bangiales,Rhodophyta)

Nuclear divisions of carpospores, conchocelis and conchospores of Porphyra yezoensis, P. haitanensis, P. katadai var. hemiphylla and P. oligospermatangia from China were investigated. The observations showed diploid chromosome numbers of 2n = 6 for P. yezoensis and P. oligospermatangia, and 2n = 10 for P. haitanensis and P. katadai var. hemiphylla. For all four species, somatic pairing of chromosome sets was observed in late prophase. Sister chromosomes separated at anaphase as mitosis took place in carpospores, conchocelis filamentous cells, conchosporangial branch cells and sporangial cells (conchospore formation). Chromosome configurations of tetrad and ring-shaped in conchospore germination were observed, demonstrating the occurrence of meiosis. The characteristics of diploid nuclear division in 2n = 6 species are the same as those of 2n = 10 species. The influence of somatic pairing on nuclear division of diploid cells in Porphyra was discussed.     

基于最大熵模型(MaxEnt)预测暗紫贝母的潜在分布

暗紫贝母(Fritillaria unibracteata)干燥的鳞茎是市场名贵药材"川贝"的主要来源,目前由于人们的过度挖采及环境的恶化,使得其野生资源已近枯竭,被列为国家三级濒危保护药材物种。该研究通过收集暗紫贝母的地理分布点经纬度,结合26项生态因子,运用最大熵模型(MaxEnt)并结合地理信息系统(ArcGIS),对其在中国的潜在分布区域进行了预测。结果表明:暗紫贝母的潜在适生区主要分布在四川西部和北部、青海南部、甘肃南部,其中四川阿坝藏族羌族自治州的理县、茂县、松潘县、红原县、黑水县等地区,青海省果洛藏族自治州的久治县、玛沁县、同德县、兴海县、河南县地区以及甘肃省甘南藏族自治州地区是暗紫贝母最佳适生区。此外,在西藏和云南也有零星的分布。对暗紫贝母的分布贡献率较大的主要生态因子有5个,分别是海拔(40.8%),年均降水量(28%),1月最高温度(7.1%),最干季平均温度(6.6%)和昼夜温差日均值(6.6%)。其中,海拔为2700~4 500m、年均降水量为400~1 400mm,是暗紫贝母最适宜生长的生态位参数。该研究结果为暗紫贝母的野生抚育和人工栽培提供了重要的科学依据。     

丫蕊花属植物花粉和种子微形态特征比较及其分类学意义

采用光学显微镜和扫描电镜,对4种丫蕊花属植物(丫蕊花、小果丫蕊花、云南丫蕊花和高山丫蕊花)的种子微形态特征及表面纹饰等进行观察,并对除云南丫蕊花外的3种丫蕊花属植物花粉形态、大小、表面纹饰等微形态特征进行观察和比较分析,并讨论了花粉及种子微形态特征的进化生物学意义,为丫蕊花属植物物种间的分类学鉴定提供理论依据。结果表明:(1)丫蕊花属植物花粉形态多为长球形,少数为超长球形,赤道面观为椭圆形,极面观为圆形,花粉大小为(22~36.5)μm×(11.5~24)μm,花粉外壁纹饰为刺状颗粒。(2)丫蕊花的花粉较大,极轴明显长于其余种,小果丫蕊花极轴长度最小。(3)花粉外壁刺状颗粒纹饰在4种丫蕊花之间存在差异性特征。(4)丫蕊花属植物种子细梭形,两端具纤维状长尾,种皮表面纹饰为复网纹纹饰。(5)云南丫蕊花的种子最大,种脊显著;小果丫蕊花种子最小。(6)组成种子表面网纹纹饰的网脊、网壁及网眼的表面特征等在各物种间存在一定差异。     

A new unconventional HLA-A2-restricted epitope from HBV core protein elicits antiviral cytotoxic T lymphocytes

Cytotoxic T cells (CTLs) play a key role in the control of Hepatitis B virus (HBV) infection and viral clearance. However, most of identified CTL epitopes are derived from HBV of genotypes A and D, and few have been defined in virus of genotypes B and C which are more prevalent in Asia. As HBV core protein (HBc) is the most conservative and immunogenic component, in this study we used an overlapping 9-mer peptide pool covering HBc to screen and identify specific CTL epitopes. An unconventional HLA-A2-restricted epitope HBc141–149 was discovered and structurally characterized by crystallization analysis. The immunogenicity and anti-HBV activity were further determined in HBV and HLAA2 transgenic mice. Finally, we show that mutations in HBc141–149 epitope are associated with viral parameters and disease progression in HBV infected patients. Our data therefore provide insights into the structure characteristics of this unconventional epitope binding to MHC-I molecules, as well as epitope specific CTL activity that orchestrate T cell response and immune evasion in HBV infected patients.     

毕赤酵母表达gp96-scFv抗体及生物活性测定

旨在利用毕赤酵母分泌表达gp96-scFv抗体,纯化后得到能特异性结合gp96抗原的小分子抗体片段(scFv)。根据gp96-scFv抗体基因序列,合成gp96-scFv抗体基因序列,将gp96-scFv抗体序列克隆到毕赤酵母表达质粒pPICZα-A,线性化的重组表达载体电转化到毕赤酵母X33,甲醇诱导目的蛋白表达,通过亲和层析法纯化目的蛋白,并以SDS-PAGE和Western blotting进行鉴定。通过Western blotting、Immunofluorescence、ELISA、FACS方法对gp96-scFv抗体的生物活性进行了检测。结果成功地构建了分泌表达抗gp96蛋白scFv抗体的毕赤酵母菌,每升毕赤酵母菌培养上清经纯化可获约50 mg gp96-scFv抗体,所获抗体其分子量大约为15 kDa,具有与gp96抗原特异性结合的活性。本研究通过毕赤酵母菌成功表达了gp96-scFv抗体,生物活性Western blotting、Immunofluorescence、ELISA、FACS分析表明该抗体能特异性结合gp96。     

高剂量热休克蛋白gp96通过激活调节性T细胞预防1型糖尿病

旨在以非肥胖糖尿病(Non-obese diabetic,NOD)小鼠为动物模型,研究高剂量昆虫细胞表达的重组热休克蛋白gp96(Recombinant gp96,rgp96)对1型糖尿病(Type 1 diabetes,T1D)的预防作用。以高剂量rgp96免疫NOD小鼠,用血糖仪监测小鼠血糖值,用流式细胞术检测小鼠脾脏CD4~+CD25~+Foxp3~+调节性T细胞(Regulatory T cells,Tregs)亚群频率,然后用一系列体外实验探究高剂量rgp96对Tregs的影响。结果显示高剂量rgp96免疫有效地预防或延缓小鼠T1D发病,免疫诱导Tregs数量明显增加。体外实验发现rgp96蛋白促进Tregs增殖,诱导Foxp3表达上调和IL-10分泌增加。研究结果为开发基于rgp96的新型T1D预防和治疗性疫苗提供了依据。     

NF-κB激活gp96转录从而促进肝细胞生长、细胞周期进展和细胞转化

【目的】探讨乙肝感染中gp96上调的机制及其可能发挥的病理学机制。【方法】首先通过生物信息学、Real-time PCR、荧光报告基因和Western blot研究NF-κB激活gp96表达的机制。进一步通过在肝细胞中过表达或敲低gp96的水平,运用CCK-8法和流式检测分析gp96对肝细胞增殖、凋亡,和细胞周期的影响,通过检测肝细胞EMT发生和细胞集落形成实验,分析gp96对于HCC发生的作用。【结果】NF-κB与gp96启动子上NF-κB结合位点结合,激活gp96的表达。实验结果显示,gp96能够促进肝细胞增殖、抑制凋亡,促进细胞周期从静息期向分裂期的转化,同时促进肝细胞EMT发生和细胞集落的形成。【结论】NF-κB通过活化gp96启动子上调其表达,为HBV慢性感染上调gp96的机制提供了线索,同时提示gp96在慢性炎症引发HCC过程中发挥重要作用。