大豆遗传转化研究进展

综述了大豆遗传转化体系及其优缺点,转基因大豆的研究成果、生产状况和生物安全性评价,分析了大豆遗传转化中存在的一些问题及其解决办法,展望了未来大豆遗传转化的发展前景。     

A concise approach to 1,11-didechloro-6-methyl-4'-O-demethyl rebeccamycin and its binding to human serum albumin: fluorescence spectroscopy and molecular modeling method

1,11-Didechloro-6-methyl-4'-O-demethyl rebeccamycin (JDC-108), a rebeccamycin analog possessing potent anti-tumor activities, was prepared via a concise one-pot strategy in good yield. The interaction between JDC-108 and human serum albumin (HSA) was studied by spectroscopic methods including fluorescence spectroscopy, UV-vis absorption spectrum, and molecular modeling. The quenching mechanism of fluorescence of HSA by JDC-108 was discussed. The number of binding sites n and apparent binding constant K were measured by fluorescence quenching method. The thermodynamic parameters DeltaH, DeltaG, DeltaS at different temperatures were calculated and the results indicated the binding reaction was mainly entropy-driven and hydrophobic forces played major role in the reaction. The distance r between donor (HSA) and acceptor (JDC-108) was obtained according to F?rster theory of non-radiation energy transfer. Synchronous fluorescence and UV-vis absorption spectrum were used to investigate the molecular conformation of HSA molecules with addition of JDC-108 and the result indicated that molecular conformation of HSA molecules was changed in the presence of JDC-108 and the hydrophobic interaction played a major role in JDC-108-HSA association, which was in good agreement with the results of molecular modeling study. In addition, the effect of common ions on the binding constants of JDC-108-HSA complex was also discussed.     

Modelling and analysis of impulsive releases of sterile mosquitoes

To study the impact of releasing sterile mosquitoes on mosquito-borne disease transmissions, we propose two mathematical models with impulsive releases of sterile mosquitoes. We consider periodic impulsive releases in the first model and obtain the existence, uniqueness, and globally stability of a wild-mosquito-eradication periodic solution. We also establish thresholds for the control of the wild mosquito population by selecting the release rate and the release period. In the second model, the impulsive releases are determined by the closely monitored wild mosquito density, or the state feedback. We prove the existence of an order one periodic solution and find a relatively small attraction region, which ensures the wild mosquito population is under control. We provide numerical analysis which shows that a smaller release rate and more frequent releases are more efficient in controlling the wild mosquito population for the periodic releases, but an early release of sterile mosquitoes is more effective for the state feedback releases.     

Highly Sensitive Biochemical Sensor Based on Two-Layer Dielectric Loaded Plasmonic Microring Resonator

In this paper, we propose and design a highly sensitive optical biochemical sensor based on two-layer dielectric loaded surface plasmon polariton waveguide (TDLSPPW)-based microring resonator (MRR). By optimizing the structure parameters, the propagation length of the proposed waveguide is ~126 μm, which is about 3 times of that of the polymer dielectric loaded surface plasmon polariton waveguide (DLSPPW) reported. It is demonstrated that the TDLSPPW-based MRR is operated at the under-coupling state, along with the quality factor (Q) of 541.2 and extinction ratio (ER) of 12.2 dB. Moreover, the Q and ER are much more sensitive to the structure parameters of the waveguide, including the waveguide width w, total thickness t, and coupling gap W _gap, compared to the low refractive index (RI) layer thickness t ₂. The simulation results on the biochemical RI sensing show that the sensitivities of 408.7 and 276.4 nm/RIU for glucose concentration in urine and chemical gases can be achieved, respectively. It is believed that the proposed sensor has potential applications in photonic-integrated biochemical sensing.     

Targeted deep sequencing reveals high diversity and variable dominance of bloom-forming cyanobacteria in eutrophic lakes

Cyanobacterial blooms in eutrophic lakes are severe environmental problems worldwide. To characterize the spatiotemporal heterogeneity of cyanobacterial blooms, a high-throughput method is necessary for the specific detection of cyanobacteria. In this study, the cyanobacterial composition of three eutrophic waters in China (Taihu Lake, Dongqian Lake, and Dongzhen Reservoir) was determined by pyrosequencing the cpcBA intergenic spacer (cpcBA-IGS) of cyanobacteria. A total of 2585 OTUs were obtained from the normalized cpcBA-IGS sequence dataset at a distance of 0.05. The 238 most abundant OTUs contained 92% of the total sequences and were classified into six cyanobacterial groups. The water samples of Taihu Lake were dominated by Microcystis, mixed Nostocales species, Synechococcus, and unclassified cyanobacteria. Besides, all the samples from Taihu Lake were clustered together in the dendrogram based on shared abundant OTUs. The cyanobacterial diversity in Dongqian Lake was dramatically decreased after sediment dredging and Synechococcus became exclusively dominant in this lake. The genus Synechococcus was also dominant in the surface water of Dongzhen Reservoir, while phylogenetically diverse cyanobacteria coexisted at a depth of 10 m in this reservoir. In summary, targeted deep sequencing based on cpcBA-IGS revealed a large diversity of bloom-forming cyanobacteria in eutrophic lakes and spatiotemporal changes in the composition of cyanobacterial communities. The genus Microcystis was the most abundant bloom-forming cyanobacteria in eutrophic lakes, while Synechococcus could be exclusively dominant under appropriate environmental conditions.     

蝴蝶兰PhalPI基因的克隆及在花器官突变体中的表达分析

为深入研究兰科植物花器官发育的调控机理,从蝴蝶兰花瓣中克隆了一个B类MADS-box转录因子PhalPI（GenBank登录号为KY020416）。序列分析表明,该基因的cDNA全长为944 bp,含完整的开放阅读框,可编码210个氨基酸,属于BGLO/PI蛋白家族,与蝴蝶兰属的PhPI10和PeMADS6基因关系最近;表达模式分析表明,PhalPI基因在生殖器官中表达,在营养器官中不表达,在授粉后的子房中,该基因的表达水平降低。在5种花器官突变体中,PhalPI基因在萼片唇瓣化突变体的萼片和蕊柱中表达水平明显升高;在雄蕊花瓣化突变体的萼片和侧瓣中表达水平降低,在其唇瓣和蕊柱中显著升高;在侧瓣合柱化突变体的蕊柱中,PhalPI基因的表达也发生了显著升高;PhalPI基因表达的改变与花器官形态的突变相关;而在侧瓣唇瓣化和侧瓣花药化突变体中,PhalPI基因的表达水平没有变化。推测该基因在决定蝴蝶兰侧瓣和唇瓣的发育中起重要的调控作用。     

Combining Energy Transfer and Optimized Morphology for Highly Efficient Ternary Polymer Solar Cells

Aimed at achieving ideal morphology, illuminating morphology–performance relationship, and further improving the power conversion efficiency (PCE) of ternary polymer solar cells (TSCs), a ternary system is designed based on PTB7‐Th:PffBT4T‐2OD:PC₇₁BM in this work. The PffBT4T‐2OD owns large absorption cross section, proper energy levels, and good crystallinity, which enhances exciton generation, charge dissociation and transport and suppresses charge recombination, thus remarkably increasing the short‐circuit current density (J _sc) and fill factor (FF). Finally, a notable PCE of 10.72% is obtained for the TSCs with 15% weight ratio of PffBT4T‐2OD. As for the working mechanism, it confirmed the energy transfer from PffBT4T‐2OD to PTB7‐Th, which contributes to the improved exciton generation. And morphology characterization indicates that the devices with 15% PffBT4T‐2OD possess both appropriate domain size (25 nm) and enhanced domain purity. Under this condition, it affords numerous D/A interface for exciton dissociation and good bicontinuous nanostructure for charge transport simultaneously. As a result, the device with 15% PffBT4T‐2OD exhibits improved exciton generation, enhanced charge dissociation possibility, elevated hole mobility and inhibited charge recombination, leading to elevated J _sc (19.02 mA cm^?2) and FF (72.62%) simultaneously. This work indicates that morphology optimization as well as energy transfer plays a significant role in improving TSC performance.     

用ISSR标记技术分析山药品种遗传多样性

利用ISSR标记技术对28个山药品种的遗传多样性进行分析。结果表明,从44条ISSR引物中可筛选出7条能够扩增出清晰、稳定条带的引物;这7条ISSR引物对28个山药品种扩增条带间存在较大差异,多态性条带比率为83.01%,Shannon多样性指数为0.3191;构建的分子树状图将28个山药品种划分为4组:第一组含有日本白、花山药和日本园3个品种;第二组为小叶山药;第三组为嵩野1号;其余23个品种归入第四组。而且主成分分析结果支持上述的聚类分析结果。这为利用ISSR标记技术鉴定山药品种,为有效地利用山药种质资源提供了依据。     

Large scale of identification of differentially expressed genes in the regenerating rat liver after SISPH

Extensive gene expression analysis was carried out after a 0, 4, 36, 72, 96 h short interval successive partial hepatectomy (SISPH) was performed. A total of 185 elements were identified as differing by more than two-fold in their expression levels at one or more time points. Of these 185 elements, 103 were up-regulated, 82 were down-regulated and 86 elements were unreported genes. Quite a few genes were previously unknown to be involved in liver regeneration (LR). Using cluster and general analysis, we found that the genes at five time points of the SISPH share eight different types of different expression profiles and eight distinct temporal induction or suppression patterns. A comparison of the gene expression in SISPH with that after PH found that 41 genes were specifically altered in SISPH, and 144 genes were simultaneously up-regulated or down-regulated in SISPH and after PH, but they were present in different amounts at the different time points. The conclusions are that (i) microarrays combined with suppressive subtractive hybridization (SSH) can effectively identify genes involved in LR on a large scale; (ii) more genes were up-regulated than down-regulated; (iii) there are fewer abundantly expressed genes than those with increased levels of 2–5 fold.     

Heat shock response and mammal adaptation to high elevation (hypoxia)

The mammal’s high elevation (hypoxia) adaptation was studied by using the immunological and the molecular biological methods to understand the significance of Hsp (hypoxia) adaptation in the organic high elevation, through the mammal heat shock response. (1) From high elevation to low elevation (natural hypoxia): Westem blot and conventional RT-PCR and real-time fluorescence quota PCR were adopted. Expression difference of heat shock protein of 70 (Hsp70) and natural expression of brain tissue of Hsp70 gene was determined in the cardiac muscle tissue among the different elevation mammals (yak). (2)From low elevation to high elevation (hypoxia induction): The mammals (domestic rabbits) from the low elevation were sent directly to the areas with different high elevations like 2300, 3300 and 5000 m above sea level to be raised for a period of 3 weeks before being slaughtered and the genetic inductive expression of the brain tissue of Hsp70 was determined with RT-PCR. The result indicated that all of the mammals at different elevations possessed their heat shock response gene. Hsp70 of the high elevation mammal rose abruptly under stress and might be induced to come into being by high elevation (hypoxia). The speedy synthesis of Hsp70 in the process of heat shock response is suitable to maintain the cells’ normal physiological functions under stress. The Hsp70 has its threshold value. The altitude of 5000 m above sea level is the best condition for the heat shock response, and it starts to reduce when the altitude is over 6000 m above sea level. The Hsp70 production quantity and the cell hypoxia bearing capacity have their direct ratio.