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TALEN or Cas9-Rapid,Efficient and Specific Choices for Genome Modifications

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Journal of Genetics and Genomics 2013年第6期40卷 281-289页

作者： Chuanxian Wei Jiyong Liu Zhongsheng Yu Bo Zhang guanjun gao Renjie Jiao State Key Laboratory of Brain and Cognitive Science Institute of BiophysicsChinese Academy of Sciences University of Chinese Academy of Sciences College of Life Sciences Peking University College of Life Sciences Tsinghua University

Precise modifications of complex genomes at the single nucleotide level have been one of the big goals for scientists working in basic and applied genetics,including biotechnology,drug development,gene therapy and synthetic ***,the relevant techniques for making these manipulations in model organisms and human cells have been lagging behind the rapid high throughput studies in the post-genomic era with a bottleneck of low efficiency,time consuming and laborious manipulation,and off-targeting *** discoveries of TALEs（transcription activator-like effectors） coding system and CRISPR（clusters of regularly interspaced short palindromic repeats） immune system in bacteria have enabled the development of customized TALENs（transcription activator-like effector nucleases） and CRISPR/Cas9 to rapidly edit genomic DNA in a variety of cell types,including human cells,and different model organisms at a very high efficiency and *** this review,we first briefly summarize the development and applications of TALENs and CRISPR/Cas9-mediated genome editing technologies;compare the advantages and constraints of each method;particularly,discuss the expected applications of both techniques in the field of site-specific genome modification and stem cell based gene therapy;finally, propose the future directions and perspectives for readers to make the choices.

关键词： Genome editing TALEN CRISPR/Cas9 Gene therapy Stem cells

Comprehensive investigation on the structural,electronic and mechanical properties of T-Mg_(32)(Al,Zn)_(49)phases in Al-Mg-Zn alloys

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Journal of Materials Science & Technology 2024年第6期173卷 237-246页

作者： Boyu Xue Wei Xiao Xiwu Li guanjun gao Xiaowu Li Yongan Zhang Ligen Wang Baiqing Xiong State Key Laboratory of Nonferrous Metals and Processes China GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China Department of Materials Physics and Chemistry School of Materials Science and EngineeringKey Laboratory for Anisotropy and Texture of MaterialsMinistry of EducationNortheastern UniversityShenyang 110819China

In the development process of crossover aluminum alloys,T-Mg_(32)(Al,Zn)_(49)phases play a significant role in the precipitation strengthening ***,comprehensive understandings of the structural characteristics,interactions among alloying elements,mechanical property dependence on composition variation,effects of doping and defects *** still inadequate.A combination of density functional theory(DFT)calculations and special quasi-random structures(SQSs)was applied to investigate the formation energies,lattice parameters,electronic structures and mechanical properties of the disordered T-phases,as well as the effects of possible defects and alloying *** formation energy and lattice constant of the T-phase gradually vary from 0 to-0.12 eV/atom and from 1.460 to 1.405 nm,respectively,with increasing Zn ***-3d orbitals exhibit stronger hybridization with Al-3s than Mg-3s orbitals,and this is further enhanced by increasing Zn contents,leading to improved covalency and mechanical properties of the *** T-phases show good ductility according to the Poisson's ratio ν,Cauchy's pressure and G/*** A site is more favorable to remain vacant in Al-rich and Zn-poor environments,which is consistent with the previous experimental *** alloying elements,Zn atoms tends to occupy Al atoms at the B,C and F sites and Mg atoms at the G *** Cu and Ag elements can decrease the formation energy of T-phases and possibly produce a greater number of T-phases during the precipitation *** effect of Ag is more significant relative to Cu due to the deeper orbital *** computational results show good agreement with previous experimental data and provide new insights into the compositional design of new Al-Mg-Zn alloys.

关键词： Al-Mg-Zn alloys Precipitation Mechanical properties Thermodynamic stability Density functional theory

Variation of airborne quartz in air of Beijing during the Asia-Pacific Economic Cooperation Economic Leaders' Meeting

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Journal of Environmental Sciences 2016年第1期28卷 62-68页

作者： Gang Li Yingming Li Hongxing Zhang Honghua Li guanjun gao Qian Zhou Yuan gao Wenjuan Li Huizhong Sun Xiaoke Wang Qinghua Zhang State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing Urban Ecosystem Research Station Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Institute of Environment and Health Jianghan University

Quartz particles are a toxic component of airborne paniculate matter（PM）.Quartz concentrations were analyzed by X-ray diffraction in eighty-seven airborne PM samples collected from three locations in Beijing before,during,and after the Asia-Pacific Economic Cooperation（APEC） Leaders＇ Meeting in *** results showed that the mean concentrations of quartz in PM samples from the two urban sites were considerably higher than those from the rural *** quartz concentrations in samples collected after the APEC meeting,when the pollution restriction lever was lifted,were higher than those in the samples collected before or during the APEC *** quartz concentrations ranged from 0.97 to 13.2 μg/m^3,which were among the highest values amid those reported from other *** highest quartz concentration exceeded the Californian Office of Environmental Health Hazard Assessment reference exposure level and was close to the occupational threshold limit values for occupational ***,a correlation analysis showed that quartz concentrations were positively correlated with concentrations of pollution parameters PM10,PM2.5,SO2 and NOx,but were negatively correlated with O3 *** results suggest that the airborne quartz particles may potentially pose health risks to the general population of Beijing.

关键词： Air pollution Carcinogen Haze PM10 Quartz

Ring-like nucleoid does not play a key role in radioresistance of Deinococcus radiodurans

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Science China(Life Sciences) 2007年第4期50卷 525-529页

作者： gao guanjun, LU HuiMing, YIN LongFei & HUA YueJin Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China Institute of Nuclear-Agricultural Sciences Zhejiang University Hangzhou China

The conclusion based on transmission electron microscopy, "the tightly packed ring-like nucleoid of the Deinococcus radiodurans R1 is a key to radioresistance", has instigated lots of debates. In this study, according to the previous research of PprI’s crucial role in radioresistance of D. radiodurans, we have attempted to examine and compare the nucleoid morphology differences among wild-type D. ra-diodurans R1 strain, pprI function-deficient mutant (YR1), and pprI function-complementary strains (YR1001, YR1002, and YR1004) before and after exposure to ionizing irradiation. Fluorescence mi-croscopy images indicate: (1) the majority of nucleoid structures in radioresistant strain R1 cells ex-hibit the tightly packed ring-like morphology, while the pprI function-deficient mutant YR1 cells carrying predominate ring-like structure represent high sensitivity to irradiation; (2) as an extreme radioresistant strain similar to wild-type R1, pprI completely function-complementary strain YR1001 almost displays the loose and irregular nucleoid morphologies. On the other hand, another radioresistant pprI partly function-complementary strain YR1002’s nucleiods exhibit about 60% ring-like structure; (3) a PprI C-terminal deletion strain YR1004 consisting of approximately 60% of ring-like nucleoid is very sensi-tive to radiation. Therefore, our present experiments do not support the conclusion that the ring-like nucleoid of D. radiodurans does play a key role in radioresistance.

关键词： Deinococcus radiodurans R1 ring-like nucleoid pprI ionizing irradiation radioresistance

Effects of Pre-Strain on Bake Hardenability and Precipitation Behavior of Al-Mg-Si Automotive Body Sheets

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Journal of Materials Science and Chemical Engineering 2024年第7期12卷 53-64页

作者： guanjun gao Lizhen Yan Xiwu Li State Key Laboratory of Non-Ferrous Metals and Processes China GRINM Group Co. Ltd. Beijing China GRIMAT Engineering Institute Co. Ltd. Beijing China General Research Institute for Nonferrous Metals Beijing China

The study investigates the effects of pre-strain on the bake hardenability and precipitation behavior of Al-Mg-Si automotive body sheets. The scanning electron microscopy, transmission electron microscopy, tensile test, Vickers hardness test, and differential scanning calorimetry were conducted for the purpose. It was found that the pre-strain treatment partially inhibits the natural aging hardening effect but cannot completely eliminate it. The pre-straining significantly enhances the bake hardening effect, with the 5% pre-strain sample showing the highest increase in yield strength and hardness. The formation of fine β" precipitates and dislocation structures contribute to the observed strengthening. Additionally, the study highlights the importance of optimizing pre-strain levels to achieve the best balance between strength and ductility in bake-hardened aluminum alloys.

关键词： Al-Mg-Si Alloy Pre-Strain Bake Hardenability Precipitation Behavior Clusters

GL3.3, a Novel QTL Encoding a GSK3/SHAGGY- like Kinase, Epistatically Interacts with GS3 to Produce Extra-long Grains in Rice

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Molecular Plant 2018年第5期11卷 754-756页

作者： Duo Xia Nao Zhou Rongjia Liu Wenhan Dan Pingbo Li Bian Wu Junxiao Chen Lingqiang Wang guanjun gao Qinglu Zhang Yuqing He Nationai Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research (Wuhan) Huazhong Agricultural University Wuhan 430070 China

Dear Editor, Grain size is a major determinant of grain yield and quality in rice （Oryza sativa）, and was therefore an important selective target during domestication and breeding （Fitzgerald et al., 2009）（Takano-Kai et al., 2009）. In the past few decades, a dozen grain size-related QTLs/genes have been cloned （Huang et al., 2013; Zuo and Li, 2014）. Pyramiding grain size QTLs to breed high-yielding and high-quality rice varieties has proved to be a great success. For example, by pyramiding the nonfunctional alleles gs3 and gw8 in line HJX74.

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The origin of Wx^(la) provides new insights into the improvement of grain quality in rice

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Journal of Integrative Plant Biology 2021年第5期63卷 878-888页

作者： Hao Zhou Duo Xia Da Zhao Yanhua Li Pingbo Li Bian Wu guanjun gao Qinglu Zhang Gongwei Wang Jinghua Xiao Xianghua Li Sibin Yu Xingming Lian Yuqing He National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research(Wuhan) Huazhong Agricultural UniversityWuhan 430070China

Appearance and taste are important factors in rice(Oryza sativa) grain quality. Here, we investigated the taste scores and related eating-quality traits of533 diverse cultivars to assess the relationships between—and genetic basis of—rice taste and eating-quality. A genome-wide association study highlighted the Wx gene as the major factor underlying variation in taste and eating quality. Notably, a novel waxy(Wx) allele, Wx^(la), which combined two mutations from Wx^(b) and Wx^(in), exhibited a unique phenotype. Reduced GBSSI activity conferred Wx^(la) rice with both a transparent appearance and good eating quality. Haplotype analysis revealed that Wx^(la) was derived from intragenic recombination. In fact,the recombination rate at the Wx locus was estimated to be 3.34 kb/c M, which was about 75-fold higher than the genome-wide mean, indicating that intragenic recombination is a major force driving diversity at the Wx locus. Based on our results, we propose a new network for Wx evolution, noting that new Wx alleles could easily be generated by crossing genotypes with different Wx alleles. This study thus provides insights into the evolution of the Wx locus and facilitates molecular breeding for quality in rice.

关键词： allelic variation appearance and eating quality intragenic recombination Oryza sativa waxy

Genetic architecture and key genes controlling the diversity of oil composition in rice grains

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Molecular Plant 2021年第3期14卷 456-469页

作者： Hao Zhou Duo Xia Pingbo Li Yiting Ao Xiaodong Xu Shanshan Wan Yanhua Li Bian Wu Huan Shi Kaiyue Wang guanjun gao Qinglu Zhang Gongwei Wang Jinghua Xiao Xianghua Li Sibin Yu Xingming Lian Yuqing He National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research(Wuhan) Huazhong Agricultural UniversityWuhan 430070China

Rice grain oil is a valuable nutrient ***,the genetic basis of oil biosynthesis in rice grains remains *** this study,we performed a genome-wide association study on oil composition and oil concentration in a diverse panel of 533 cultivated rice *** variation for 11 oil-related traits was observed,and the oil composition of rice grains showed differentiation among the *** identified 46 loci that are significantly associated with grain oil concentration or composition,16 of which were detected in three recombinant inbred line ***-six candidate genes encoding enzymes involved in oil metabolism were identified from these 46 loci,four of which(PAL6,LIN6,MYR2,and ARA6)were found to contribute to natural variation in oil composition and to show differentiation among the ***,population genetic analyses revealed that specific haplotypes of PAL6 and LIN6 have been selected in japonica *** on these results,we propose a possible oil biosynthetic pathway in rice ***,our results provide new insights into the genetic basis of oil biosynthesis in rice grains and can facilitate marker-based breeding of rice varieties with enhanced oil and grain quality.

关键词： Oryza sativa L grain oil genome-wide association study genetic basis oil biosynthesis

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海底光缆系统经济性建模及快速规划算法

光通信研究 2024年第3期3期(20)卷 92-98页

作者：高雯静高冠军北京邮电大学信息光子学与光通信全国重点实验室北京100876

【目的】海底光缆在国际通信链路中占据主导地位,在进行海底光缆通信系统的规划时往往是根据经验确定几组可能的方案,然后比选出传输性能和投资成本相对较优的方案。然而,随着通信设备和通信技术的发展,可选的调制格式和光纤数量不断增... 详细信息

【目的】海底光缆在国际通信链路中占据主导地位,在进行海底光缆通信系统的规划时往往是根据经验确定几组可能的方案,然后比选出传输性能和投资成本相对较优的方案。然而,随着通信设备和通信技术的发展,可选的调制格式和光纤数量不断增加,备选方案数量较多,无法快速确定最优方案。因此,有必要建立一个海底光缆通信系统的成本最优化模型,求解成本最优的系统规划方案。【方法】针对海底光缆通信系统中的系统规划配置问题,以跨段距离、光纤类型、光纤纤对数量、中继器输出功率、调制格式和实用信道数为研究变量,建立一个以传输性能、传输容量和供电电压为约束条件的成本最优化模型,利用级联遗传-字典序法对成本最优化模型进行求解计算。【结果】结果表明,文章所提优化算法与全遍历算法的规划结果差异不超过0.34%,但该优化算法运算次数远少于全遍历算法的运算次数,仅为全遍历算法的1/100。其次,级联遗传-字典序法的运算次数受变量范围的影响小于全遍历算法。最后,通过对比不同跨段距离下海底光缆通信系统的最优成本,发现其规划结果不具有规律性。【结论】各个设计变量之间相互影响,系统的最优成本设计无法根据经验得到,需要建立模型求解;文章采用的算法不仅运算结果精确,而且运算次数较少。

关键词：海底光缆通信系统经济性建模遗传算法字典序法