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目的 研究回转器模拟微重力对革兰氏阴性菌大肠杆菌(Escherichia coli)基因与蛋白表达的影响.方法 采用回转器模拟微重力效应,连续2周作用于大肠杆菌ATCC 25922菌株,选取16个靶基因,RTPCR反应检测处理菌株和对照菌株基因表达的变化;提取菌体蛋白进行双向电泳,电泳图谱采用Image Master 2D Platinum软件分析,找出差异表达蛋白,进行基质辅助激光解吸飞行时间质谱(MALDI TOF/TOF质谱)分析.结果 在模拟微重力效应作用下,处理菌株与对照菌株相比,16个靶基因中有4个靶基因表达上调,5个下调;15个差异表达蛋白点,其中4个表达上调蛋白质谱鉴定为抗转录终止蛋白NusG、固氮铁蛋白、硫醇过氧化物酶,1个表达下调蛋白为未知蛋白,2个新增蛋白为谷氨酰胺ABC转运周质蛋白,1个表达消失蛋白为IclR转录调节蛋白家族.结论 模拟微重力效应可引起大肠杆菌基因及功能蛋白表达的变化.“,”Objective To study the effects of simulated microgravity with clinostat on expression of gene and protein in Escherichia coli.Methods Escherichia coli ATCC 25922 strain was treated by clinostat for 2 weeks,16 target genes were selected,two-dimensional electrophoresis and mass spectrum were used to detect changes in protein expression and composition.RT-PCR was performed to detect different kinds of gene expressions in treated and untreated strains.Then total protein was extracted and used in two-dimensional electrophoresis analysis.Matrix assisted laser desorption/ionization - time of flight mass spectrometry (MALDI TOF/TOF MS) was used to analyze differential expression of protein between treated and untreated strains.Results With the treatment of simulated microgravity,four kinds of gene expressions were significantly up-regulated and five gene expressions were significantly down-regulated among 16 target genes; For 15 differential expression of protein,transcription antitermination factor NusG,redoxin and thiol peroxidase were up-regulated,hypothetical protein was down-regulated.Newly emerged proteins included glutamine ABC transporter periplasmic protein,and disappeared proteins were transcriptional regulator IclR family.Conclusion Simulated microgravity with clinostat(SMC) can induce variations in expression of gene and functional protein in Escherichia coli.