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| 1 | Terrestrial carbon sinks in China and around the world and their contribution to carbon neutrality显示文摘Enhancing the terrestrial ecosystem carbon sink(referred to as terrestrial C sink) is an important way to slow down the continuous increase in atmospheric carbon dioxide(CO_(2)) concentration and to achieve carbon neutrality target.To better understand the characteristics of terrestrial C sinks and their contribution to carbon neutrality,this review summarizes major progress in terrestrial C budget researches during the past decades,clarifies spatial patterns and drivers of terrestrial C sources and sinks in China and around the world,and examines the role of terrestrial C sinks in achieving carbon neutrality target.According to recent studies,the global terrestrial C sink has been increasing from a source of (-0.2±0.9) Pg C yr^(-1)(1 Pg=1015g)in the 1960s to a sink of (1.9±1.1) Pg C yr^(-1) in the 2010s.By synthesizing the published data,we estimate terrestrial C sink of 0.20–0.25 Pg C yr^(-1) in China during the past decades,and predict it to be 0.15–0.52 Pg C yr^(-1) by 2060.The terrestrial C sinks are mainly located in the mid-and high latitudes of the Northern Hemisphere,while tropical regions act as a weak C sink or source.The C balance differs much among ecosystem types:forest is the major C sink;shrubland,wetland and farmland soil act as C sinks;and whether the grassland functions as C sink or source remains unclear.Desert might be a C sink,but the magnitude and the associated mechanisms are still controversial.Elevated atmospheric CO_(2) concentration,nitrogen deposition,climate change,and land cover change are the main drivers of terrestrial C sinks,while other factors such as fires and aerosols would also affect ecosystem C balance.The driving factors of terrestrial C sink differ among regions.Elevated CO_(2) concentration and climate change are major drivers of the C sinks in North America and Europe,while afforestation and ecological restoration are additionally important forcing factors of terrestrial C sinks in China.For future studies,we recommend the necessity for intensive and long-term ecosystem C monitoring over broad geographic scale to improve terrestrial biosphere models for accurately evaluating terrestrial C budget and its dynamics under various climate change and policy scenarios. | Yuanhe Yang Yue Shi Wenjuan Sun Jinfeng Chang Jianxiao Zhu Leiyi Chen Xin Wang Yanpei Guo Hongtu Zhang Lingfei Yu Shuqing Zhao Kang Xu Jiangling Zhu Haihua Shen Yuanyuan Wang Yunfeng Peng Xia Zhao Xiangping Wang Huifeng Hu Shiping Chen Mei Huang Xuefa Wen Shaopeng Wang Biao Zhu Shuli Niu Zhiyao Tang Lingli Liu Jingyun Fang | 2022 | Science China(Life Sciences)2022,65,5: | 32 |
| 2 | Copper ions influence the toxicity of β-amyloid(1-42) in a concen-tration-dependent manner in a Caenorhabditis elegans model of Alzheimer’s disease显示文摘β-amyloid (Aβ) and copper play important roles in the pathogenesis of Alzheimer’s disease (AD).However,the behavioral correlativity and molecular mechanisms of Aβ and copper toxicity have been investigated less often.In the present study,we investigated the interaction and toxicity of Aβ1-42 and copper in the Aβ1-42 transgenic Caenorhabditis elegans worm model CL2006.Our data show that the paralysis behavior of CL2006 worms significantly deteriorated after exposure to 10-3 mol L-1 copper ions.However,the paralysis behavior was dramatically attenuated with exposure to 10-4 mol L-1 copper ions.The exogenous copper treatment also partially changed the homeostatic balance of zinc,manganese,and iron.Our data suggest that the accumulation of reactive oxygen species (ROS) was responsible for the paralysis induced by Aβ and copper in CL2006.The ROS generation induced by Aβ and copper appear to be through sod-1,prdx-2,skn-1,hsp-60 and hsp-16.2 genes. | LUO YunFeng ZHANG Jie LIU NianQing LUO Yuan ZHAO BaoLu | 2011 | Science China(Life Sciences)2011,54,6: | 26 |
| 3 | Occurrence of perfluoroalkyl substances in matched human serum,urine,hair and nail显示文摘The purpose of this study was to determine perfluoroalkyl substances(PFASs) in human serum, urine, hair and nail from general populations, and to investigate the possibility for human urine, hair and nail used as the biomonitoring sample for PFASs exposure. We detected the concentrations of PFHx A, PFOA, PFNA, PFDA, PFUn DA, PFDo A, PFHx S and PFOS in 39 matched human serum, urine, hair and nail samples from Shenzhen in China. The detection frequency and the median level of PFOS were all higher than that of the other PFASs in four matrices. The median concentration of PFOS in serum, urine, hair, and nail were 9.24 ng/mL, 13.96 ng/L, 0.58 ng/g and 0.63 ng/g, respectively. The results of spearman correlation test indicated that nail was an ideal matrix for biomonitoring PFOS rather than human urine and hair in general populations for the non-invasive sampling. | Yuxin Wang Yuxin Zhong Jingguang Li Jianqing Zhang Bing Lyu Yunfeng Zhao Yongning Wu | 2018 | Journal of Environmental Sciences2018,30,5: | 17 |
| 4 | Experimental demonstration of a new concept of drag reduction and thermal protection for hypersonic vehicles显示文摘A new idea of drag reduction and thermalprotection for hypersonic vehicles is proposed based on thecombination of a physical spike and lateral jets for shock-reconstruction. The spike recasts the bow shock in front ofa blunt body into a conical shock, and the lateral jets workto protect the spike tip from overheating and to push theconical shock away from the blunt body when a pitchingangle exists during flight. Experiments are conducted in ahypersonic wind tunnel at a nominal Mach number of 6. Itis demonstrated that the shock/shock interaction on the bluntbody is avoided due to injection and the peak pressure atthe reattachment point is reduced by 70% under a 4°attackangle. | Zonglin Jiang Yunfeng Liu Guilai Han Wei Zhao Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China | 2009 | Acta Mechanica Sinica2009,25,3: | 14 |
| 5 | Earthquake prediction from China's mobile gravity data显示文摘The relation between plate tectonics and earthquake evolution is analyzed systematically on the basis of 1998e2010 absolute and relative gravity data from the Crustal Movement Observation Network of China. Most earthquakes originated in the plate boundary or within the fault zone. Tectonic deformation was most intense and exhibited discontinuity within the tectonically active fault zone because of the differential movement; the stress accumulation produced an abrupt gravity change, which was further enhanced by the earthquake. The gravity data from China's Mainland since 2000 obviously reflected five major earthquakes(Ms > 7), all of which were better reflected than before 2000. Regional gravity anomalies and a gravity gradient change were observed in the area around the epicenter about 2 or 3 years before the earthquake occurred, suggesting that gravity change may be a seismic precursor. Furthermore, in this study, the medium-term predictions of the Ms7.3 Yutian, Ms8.0 Wenchuan, and Ms7.0 Lushan earthquakes are analytically presented and evaluated, especially to estimate location of earthquake. | Zhu Yiqing Liu Fang You Xinzhao Liang Weifeng Zhao Yunfeng Liu Lian | 2015 | Geodesy and Geodynamics2015,6,2: | 13 |
| 6 | Large-field high-resolution two-photon digital scanned light-sheet microscopy显示文摘 | Weijian Zong Jia Zhao Xuanyang Chen Yuan Lin Huixia Ren Yunfeng Zhang Ming Fan Zhuan Zhou Heping Cheng Yujie Sun Liangyi Chen | 2015 | Cell Research2015,25,2: | 12 |
| 7 | Lumbar spine superior-level facet joint violations: percutaneous versus open pedicle screw insertion using intraoperative 3-dimensional computer-assisted navigation显示文摘 | Tian Wei Xu Yunfeng Liu Bo Liu Yajun He Da Yuan Qiang Lang Zhao Lyu Yanwei Han Xiaoguang Jin Peihao | 2014 | Chinese Medical Journal2014,,22: | 10 |
| 8 | Association of serum levels of perfluoroalkyl substances with gestational diabetes mellitus and postpartum blood glucose显示文摘This study was conducted to examine the association of perfluoroalkyl substance(PFAS)exposure with gestational diabetes mellitus(GDM) risk and postpartum fasting blood glucose.We used a 1:2 matched case–control study with 84 GDM subjects and 168 healthy pregnant women from Beijing, China. The maternal blood was collected at 1–2 days before delivery, and eight linear isomers and fourteen branched isomers were determined in maternal serum.Logistic regression analyses were performed to evaluate the associations after adjusting for potential confounders. The median of the sum of levels of total PFASs was 4.24 ng/m L with a interquartile range(IQR) of 2.82–6.54 ng/m L. Although maternal PFAS exposure was not associated with risk of GDM, significant positive associations were observed between evaluated exposure to specific PFAS congeners and increasing blood glucose. The odds ratio(ORs) of the highest category of postpartum fasting blood glucose for perfluoro-1-metylheptylsulfonat(1 m-PFOS), perfluoro-3/4-metylheptylsulfonat(3 m+4 m-PFOS), perfluoro-5-metylheptylsulfonat(5 m-PFOS), and perfluorohexane sulfonate(PFHx S) were 2.03(95% CI: 1.09–3.77), 1.93(95% CI:1.04–3.58), 2.48(95% CI: 1.33–4.65), and 2.26(95% CI: 1.21–4.21), respectively, suggesting negative effects of maternal exposure to specific PFAS compounds on glucose metabolism. | Yuxin Wang Lei Zhang Yue Teng Jiayu Zhang Lin Yang Jingguang Li Jianqiang Lai Yunfeng Zhao Yongning Wu | 2018 | Journal of Environmental Sciences2018,30,7: | 8 |
| 9 | Gravity changes before and after the 2010 Ms7.1 Yushu earthquake显示文摘Absolute and relative gravity observations from 1998-2010 from the China Crustal Movement Observation Network, a major national scientific project, have been used to model the gravity field and its variations associated with the April 14, 2010 Ms7.1 Yushu earthquake. The evolution of the regional gravity field and its relationship with seismicity before and after the Yushu earthquake are studied. The observed gravity changes are closely related to the active Ganzi-Yushu Fault, and gravity measurements can be used to observe the migration of material accompanying active faults and crustal tectonics. The dynamic variation of the gravity field reflects its evolution prior to and during the Yushu earthquake. The gravity measurements near its epicenter are as large as 80×10^(-8) m/s^2, and they show wave-like increases with time prior to the Yushu earthquake. | Zhu Yiqing Liu fang Cao Jianping Zhao Yunfeng | 2012 | Geodesy and Geodynamics2012,3,4: | 7 |
| 10 | Particle-bound PCDD/Fs in the Atmosphere of an Electronic Waste Dismantling Area in China显示文摘Objective Particulate samples from the atmosphere in an electronic waste dismantling area were collected to investigate the levels and sources of polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/Fs). Methods Particulate samples including total suspended particulates (TSP) and particulate matter <2.5 μm diameter (PM2.5) were collected on selected non‐rainy days in summer (Jul 10-12, 2006) and winter (Jan 11-13, 2007) from Fengjiang (FJ), an electronic waste (e‐waste) dismantling area in eastern China, and an adjacent area Luqiao (LQ). The samples were analyzed by isotope dilution ‐ high resolution gas chromatography / high resolution mass spectrometry (HRGC/HRMS). Results In FJ, the mean PCDD/F concentrations (mean TEQ values) were 280.6 pg Nm‐3 (3.432 pg WHO‐TEQ Nm‐3) for the TSP samples and 223.3 pg Nm‐3 (3.180 pg WHO‐TEQ Nm‐3) for the PM2.5 samples. The total PCDD/F concentrations and TEQs in the PM2.5 samples were about 66.8%‐108.0% of the TSP samples, indicating that the fine particles contained higher levels of PCDD/Fs than coarse particles. The PCDD/F levels in FJ were much higher than those detected in common urban areas around the world, suggesting that the study area was heavily polluted by PCDD/Fs. Furthermore, the total average daily PCDD/F intake in FJ was estimated at 62.11 pg WHO‐TEQ kg‐1·day‐1 for adults and 110.11 pg WHO‐TEQ kg‐1·day‐1 for children, which greatly exceeds the WHO (1998) tolerable daily intake of 1-4 pg of WHO‐TEQ kg‐1·day‐1. Conclusion The PCDD/F homologues and congener profiles confirmed that the PCDD/Fs in FJ originated from crude e‐waste recycling activities. The severe dioxin pollution present in FJ has also substantially influenced the adjacent area of LQ through atmospheric transport. Open burning of medical waste was another source of PCDD/Fs identified in LQ. | WEN Sheng GONG Yan LI JingGuang SHI TingMing ZHAO YunFeng WU YongNing | 2011 | Biomedical and Environmental Sciences2011,24,2: | 6 |
| 11 | Genetic analysis and molecular mapping of a novel gene for zebra mutation in rice (Oryza sativa L.)显示文摘A novel zebra mutant,zebra-15,derived from the restorer line Jinhui10(Oryza sativa L. ssp. indica) treated by EMS,displayed a distinctive zebra leaf from seedling stage to jointing stage. Its chlorophyll content decreased(55.4%) and the ratio of Chla/Chlb increased(90.2%) significantly in the yellow part of the zebra-15,compared with the wild type. Net photosynthetic rate and fluorescence kinetic parameters showed that the decrease of chlorophyll content significantly influenced the photosynthetic efficiency of the mutant. Genetic analysis of F2 segregation populations derived from the cross of Xinong1A and zebra-15 indicated that the zebra leaf trait is controlled by a single recessive nuclear gene. Ninety-eight out of four hundred and eighty pairs of SSR markers showed the diversity between the Xinong1A and the zebra-15,their F2 population was then used for gene mapping. Zebra-15(Z-15) gene was primarily restricted on the short arm of chromosome 5 by 150 F2 recessive individuals,19.6 cM from marker RM3322 and 6.0 cM from marker RM6082. Thirty-six SSR markers were newly designed in the restricted location,and the Z-15 was finally located between markers nSSR516 and nSSR502 with the physical region 258 kb by using 1,054 F2 recessive individuals. | Qiushi Wang,Xianchun Sang,Yinghua Ling,Fangming Zhao,Zhenglin Yang,Yunfeng Li,Guanghua He Key Laboratory of Biotechnology and Crop Quality Improvement,Ministry of Agriculture Rice Research Institute,Southwest University,Chongqing 400716,China | 2009 | Journal of Genetics and Genomics2009,36,11: | 5 |
| 12 | 昆虫性信息素配备新型飞蛾诱捕器群集诱杀水稻二化螟的效果研究显示文摘对新型飞蛾干式诱捕器诱捕效率进行了测试,从6月20日至9月20日,共调查13次,累计诱蛾量8 605头,平均每台诱捕器诱蛾344头。性诱剂处理区、施药区和不施药区虫伤株率分别为为1.77%、1.19%和81.90%,枯鞘率分别为1.11%、0.65%和14.68%,白穗率分别为1.87%、0.35%和38.83%。性诱剂防治效果95.18%,比药剂防效低3.92个百分点。就本试验结果来看,新型诱捕器操作简便,易于维护,使性信息素大面积诱杀二化螟的可行性提高。 | 司兆胜 宫香余 翟宏伟 ZHAO Yunfeng | 2016 | 中国稻米2016,22,4: | 5 |
| 13 | Surface-tailored PtPdCu ultrathin nanowires as advanced electrocatalysts for ethanol oxidation and oxygen reduction reaction in direct ethanol fuel cell显示文摘The development of advanced electrocatalysts for efficient catalyzing ethanol oxidation reaction(EOR)and oxygen reduction reaction(ORR) is significant for direct ethanol fuel cells(DEFCs).However,in many previous studies,the major difficulties including lower utilization efficiency and weaker anti-CO-poison ability of Pt hamper the practical testing of such DEFCs,Herein,ternary Pt22Pd27C51 ultrathin(~5 nm)NWs are fabricated via a facile surfactant-free strategy.The surface and electronic structures of Pt22Pd27Cu51 NWs are further tailored via acid-etching treatment.The resulted PtPdCu NWs with an optimal atomic Pt/Pd/Cu ratio of 36:41:23 display excellent specific activities towards EOR(4.38 mA/cm^(2))and ORR(1.16 mA/cm^(2)),which are 19.8-and 5.7-folds larger than that of Pt/C,respectively.A singlecell was fabricated using Pt36Pd41Cu23 NWs as electrocatalyst in both anode and cathode with Pt loading of 1.2 mgpt/cm^(2).The power density measured at 80 ℃ is 21.7 mW/cm^(2),which is ~3.9 folds enhancement relative to that fabricated by using Pt/C(2 mgPt/cm^(2)).The enhanced catalytic performance of Pt36Pd41Cu23NWs could be attributed to that synergistic effect between Pt,Pd and Cu enhances CO anti-poisoning ability and promotes the C-C bond cleavage.This work provides a promising strategy for developing efficient electrocatalysts for DEFCs. | Kaili Wang Fei Wang Yunfeng Zhao Weiqing Zhang | 2021 | Journal of Energy Chemistry2021,30,1: | 5 |
| 14 | Enhancement of the Photoelectric Performance of Dye-sensitized Solar Cells by Sol-gel Modified TiO_2 Films显示文摘Modified TiO2 films have been prepared by combining commercial titania powders (Degussa P25) with sol-gel made by titanium chloride (Ti-sol). The result shows that clusters are formed by nanoparticles and large pores can be seen on the surface of the TiO2 films. The short circuit photocurrent density and photoelectric conversion efficiency of the solar cells are obviously enhanced compared with those without modification. The relationship between the photoelectric conversion efficiency and the amount of Ti-sol was investigated. With the addition of 30 wt% Ti-sol, the photoelectric conversion efficiency as high as 9.75% is achieved, increasing by 28.3% compared with the solar cells without modification. | Yunfeng Zhao Xiaojie Li Qiuping Li Changsheng Deng | 2011 | Journal of Materials Science & Technology2011,27,8: | 4 |
| 15 | Erythromycin loaded by tetrahedral framework nucleic acids are more antimicrobial sensitive against Escherichia coli(E.coli)显示文摘Erythromycin is a commonly used broad-spectrum antibiotic,but resistance to this antibiotic makes its use less effective.Considerable efforts,beside finding alternatives,are needed to enhance its antimicrobial effect and stability against bacteria.Tetrahedral framework nucleic acids(tFNAs),a novel delivery vehicle with a three-dimensional nanostructure,have been studied as a carrying platform of antineoplastic drugs.In this study,the use of tFNAs in delivering erythromycin into Escherichia coli(E.coli)was investigated for the first time.The tFNAs vehicle increased the bacterial uptake of erythromycin and promoted membrane destabilization.Moreover,it increased the permeability of the bacterial cell wall,and reduced drug resistance by improving the movement of the drug across the membrane.The tFNAs-based delivery system enhanced the effects of erythromycin against E.coli.It may therefore provide an effective delivery vehicle for erythromycin in targeting antibiotic-resistant bacteria with thick cell wall. | Yue Sun Yuhao Liu Bowen Zhang Shirong Shi Tao Zhang Dan Zhao Taoran Tian Qirong Li Yunfeng Lin | 2021 | Bioactive Materials2021,6,8: | 4 |
| 16 | Gravity variations before the Menyuan Ms6.4 earthquake显示文摘In order to study the relationship between gravity variation and Menyuan Ms6.4 earthquake, gravity variation characteristics in mid-eastern of Qilian Mountain were analyzed based on the 2012-2015 relative gravity datasets. The results indicated that the gravity changes in mid-eastern of Qilian Mountain increased gradually, while gravity changes around Menyuan remarkably. Besides, great positive-negative gravity changing gradients appeared along the Lenglongling Fault which was located at the north of Menyuan, and the 2016 Menyuan Ms6.4 earthquake occurred near the junction of positive and negative gravity changes. | Weifeng Liang Guoqing Zhang Yiqing Zhu Yunma Xu Shusong Guo Yunfeng Zhao Fang Liu Lingqiang Zhao | 2016 | Geodesy and Geodynamics2016,7,4: | 3 |
| 17 | Vapor deposition of aluminium oxide into N-rich mesoporous carbon framework as a reversible sulfur host for lithium-sulfur battery cathode显示文摘Restraining the shuttle effects of lithium polysulfides is the key to improve the cycling reversibility and stability of lithium-sulfur(Li-S)batteries for which design of robust sulfur hosts has been regarded as the most effective strategy.In this work,we report a new type of hybrid sulfur host which is composed of Al_(2)O_(3) homogenously decorated in nitrogen-rich mesoporous carbon framework(NMC-Al_(2)O_(3)).The NMC-Al_(2)O_(3) hybrid host features a poly-dispersed spherical morphology and a mesoporous configuration with high surface area and large pore volume that can accommodate a high sulfur content up to 73.5 wt.%.As a result,the fabricated NMC-Al_(2)O_(3)-S cathode exhibits all-round improvements in electrochemical properties in term of capacities(1,212 mAh·g^(-1)at 0.2 C;755 mAh·g^(-1)at 2 C),cycling charge-discharge reversibility(sustainably 100%efficiencies)and stability(1,000 cycles with only 0.023%capacity decay per cycle at 0.5 C).By contrast,the Al_(2)O_(3)-free NMC-S cathode shows both decreased capacities and rapidly descending Coulombic efficiencies during cycling.Density functional theory(DFH')calculations further reveal that the implanted Al_(2)O_(3) can greatly enhance the chemical adsorption and catalytic conversion for various lithium polysulfides and thereby effectively prevent the polysulfide shuttling and significantly improve the utilizability,reversibility and stability of sulfur cathode. | Fei Sun Zhibin Qu Hua Wang Xiaoyan Liu Tong Pei Rui Han Jihui Gao Guangbo Zhao Yunfeng Lu | 2021 | Nano Research2021,14,1: | 3 |
| 18 | Soil particle and moisture-related factors determine landward distribution of bacterial communities in a lateral riverside continuum of the Xilin River Basin显示文摘Continuous landscape components along the lateral riverside are affected by both hydrologic connectivity and disconnectivity.In recent years,anthropogenic activities and climate changes have caused wetland shrinkage and land degradation along the lateral riverside of many arid and semiarid regions.Since microorganisms are major drivers of soil biochemical cycling,it is essential to examine soil microbial communities along the lateral landscape continuum to understand their ecosystem functioning and predict future land changes.Here,we collected samples along a lateral riverbed center-riverbed edge-oxbow lake-floodplain-terrace continuum(i.e.,landward distribution)in the Xilin River Basin,Inner Mongolia,China.The floodplain had the highest microbial diversity and heterogeneity,with Bacteroidetes,β-andγ-Proteobacteria being the most abundant taxa.In contrast,the terrace had the lowest microbial diversity and heterogeneity,with Acidobacteria,Actinobacteria,Verrucomicrobia,Gemmatimonadetes,andα-Proteobacteria as the most abundant taxa.Silt particle,salinity,and moisture were the most influential factors for landward variation of bacterial communities along the riverside continuum.Altogether,we demonstrate that dominant bacterial lineages,soil particles,and moisture-related factors are valuable indicators of this continuum,which can be leveraged for the early prediction of drought-induced wetland shrinkage and grassland desertification. | Jingli Yu Jingjing Xia Qiaoli Ma Chi Zhang Ji Zhao Xininigen Tanggood Yunfeng Yang | 2021 | Soil Ecology Letters2021,3,4: | 3 |
| 19 | Japanese Encephalitis Virus NS1' Protein Antagonizes Interferon Beta Production显示文摘Japanese encephalitis virus(JEV) is a mosquito-borne virus and the major cause of viral encephalitis in Asia. NS1', a52-amino acid C-terminal extension of NS1, is generated with a-1 programmed ribosomal frameshift and is only present in members of the Japanese encephalitis serogroup of flaviviruses. Previous studies demonstrated that NS1' plays a vital role in virulence, but the mechanism is unclear. In this study, an NS1' defected(rG66A) virus was generated. We found that rG66A virus was less virulent than its parent virus(pSA14) in wild-type mice. However, similar mortality caused by the two viruses was observed in an IFNAR knockout mouse model. Moreover, we found that rG66A virus induced a greater type Ⅰ interferon(IFN) response than that by pSA14, and JEV NS1' significantly inhibited the production of IFN-b and IFN-stimulated genes. Taken together, our results reveal that NS1' plays a vital role in blocking type I IFN production to help JEV evade antiviral immunity and benefit viral replication. | Dengyuan Zhou Fan Jia Qiuyan Li Luping Zhang Zheng Chen Zikai Zhao Min Cui Yunfeng Song Huanchun Chen Shengbo Cao Jing Ye | 2018 | Virologica Sinica2018,33,6: | 3 |
| 20 | Regulation of U6 Promoter Activity by Transcriptional Interference in Viral Vector-Based RNAi显示文摘The direct negative impact of the transcriptional activity of one component on the second one in cis is referred to as transcriptional interference (TI). U6 is a type III RNA polymerase III promoter commonly used for driving small hairpin RNA (shRNA) expression in vector-based RNAi. In the design and construction of viral vectors, multiple transcription units may be arranged in close proximity in a space-limited vector. Determining if U6 promoter activity can be affected by TI is critical for the expression of target shRNA in gene therapy or loss-of-function studies. In this research, we designed and implemented a modified retroviral system where shRNA and exogenous gene expressions were driven by two independent transcriptional units. We arranged U6 promoter driving shRNA expression and UbiC promoter in two promoter arrangements. In primary macrophages, we found U6 promoter activity was inhibited by UbiC promoter when in the divergent arrangement but not in tandem. In contrast, PKG promoter had no such negative impact. Instead of enhancing U6 promoter activity, CMV enhancer had significant negative impact on U6 promoter activity in the presence of UbiC promoter. Our results indicate that U6 promoter activity can be affected by TI in a proximal promoter-specific and arrangement-dependent manner. | Linghu Nie Meghna Das Thakur Yumei Wang Qin Su Yongliang Zhao Yunfeng Feng | 2010 | Genomics, Proteomics & Bioinformatics2010,8,3: | 3 |