目的:了解我国利福平敏感结核杆菌rpoB基因利福平耐药决定区(rifampicin resistancedetermining region,RRDR)序列的多态性特征。方法:采用"rpoB AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Macon OR Taiwan)"...目的:了解我国利福平敏感结核杆菌rpoB基因利福平耐药决定区(rifampicin resistancedetermining region,RRDR)序列的多态性特征。方法:采用"rpoB AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Macon OR Taiwan)"检索策略在Pubmed数据库中检索文献,循证分析Pubmed数据库中截止至2013年4月30日有关我国结核杆菌rpoB基因突变分子特征的研究文献。结果:36篇文献纳入研究,5 136株利福平敏感结核杆菌rpoB基因RRDR序列信息得以分析,38株(0.74%)rpoB基因RRDR序列呈现基因突变,涉及8个位点,分别为511(11株)、533(7株)、531(6株)、526(5株)、516(4株)、518(2株)、519(2株)、521(2株)等,其中1株涉及511/526双位点。结论:我国结核杆菌rpoB基因RRDR序列存在沉默突变现象,并非所有RRDR序列改变均与结核杆菌利福平药物敏感性有关。展开更多
目的利用毕赤酵母高效表达人组织因子途径抑制因子(TFPI)。方法利用基因定点突变技术对人TFPIcDNA特定序列进行定点突变(同义突变)。将获得的突变体及野生型cDNA分别插入表达载体pPic9中,转化酵母宿主菌GS115和KM71,用0.5%的甲醇诱导重...目的利用毕赤酵母高效表达人组织因子途径抑制因子(TFPI)。方法利用基因定点突变技术对人TFPIcDNA特定序列进行定点突变(同义突变)。将获得的突变体及野生型cDNA分别插入表达载体pPic9中,转化酵母宿主菌GS115和KM71,用0.5%的甲醇诱导重组蛋白表达。细胞培养上清经超滤浓缩后,依次用DEAE-sepharose Fast Flow、Heparin-sepharose CL6B及Sephadex G-75柱层析分离纯化得到重组蛋白,分别采用凝胶扫描成像定量分析和底物显色法测定重组蛋白的表达量和活性。结果凝胶扫描成像定量分析显示,同义突变体的表达量(1mg/L)显著高于天然型(0.1mg/L)。活性测定表明GS115重组菌在诱导表达12h后即可于培养上清中检测到TFPI活性,36h达峰值;而KM71重组菌诱导表达24h后才开始于培养上清中检测到TFPI活性,72h达峰值。两个菌株中突变体mTFPI-pPic9转化子的表达量均显著高于TFPI-pPic9转化子。重组蛋白相对分子质量约为42000。结论对TFPI-cDNA特定序列进行同义突变后能显著提高重组蛋白在毕赤酵母细胞中的表达,且显著高于在酿酒酵母和昆虫细胞的表达;重组蛋白具有良好的生物活性。因此,利用毕赤酵母表达TFPI是一种较好的选择。展开更多
An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced...An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced in the research station of North Bengal Agricultural University (27.06°N 88.47°E) situated in north eastern Himalayan region of Darjeeling district in the state of West Bengal from Sikkim Sangtok (27°25'N 88°31'E) of north Sikkim area in India for the purpose of conservation. As we noticed some irregular development of floral organs, we investigated some pertinent questions regarding ecological aberrations found in plants. We found plants introduced in north eastern Himalayan region changed their homology of number flower petals and position of stamens seen naturally in north western Himalayan region as per the reports. Was there any genetic or extreme environmental stress condition caused a sudden change in floral structure as it is generally known as a rare phenomenon and frequently not seen? What were the correlations of different floral parts and fitness of population in different morphotypes? We predicted possible outcomes of seed setting by univariate regression models in a particular environment in addition to this investigation. We proposed three models of heterozygousity for answering the reasons of unstable floral form from a general known floral form, where silent mutations help the plants to survive in adverse conditions in spite of deformed or variable formed of floral morphology.展开更多
A silent mutation or sequence polymorphism, A to T substitution at codon 399 in exon11 of the PAH gene from a Chinese PKU patient, was found by sequence analysis. The fre-quencies of this new mutation in normal and ab...A silent mutation or sequence polymorphism, A to T substitution at codon 399 in exon11 of the PAH gene from a Chinese PKU patient, was found by sequence analysis. The fre-quencies of this new mutation in normal and abnormal (PKU) genes were 0.005 and 0.09,respectively, based on the analyses of 100 normal individuals and 39 PKU patients usingDNA amplification with polymerase chain reaction (PCR) and oligonucleotide hybridizationmethods. This silent mutation can be used as a "genetic marker" for PKU prenatal diagno-sis. Recently, a fetus at risk for PKU, who could not be completely predicted by RFLPslinkage analysis, was prenatally diagnosed with this genetic marker.展开更多
文摘目的:了解我国利福平敏感结核杆菌rpoB基因利福平耐药决定区(rifampicin resistancedetermining region,RRDR)序列的多态性特征。方法:采用"rpoB AND Mycobacterium tuberculosis AND(China OR Hong Kong OR Macon OR Taiwan)"检索策略在Pubmed数据库中检索文献,循证分析Pubmed数据库中截止至2013年4月30日有关我国结核杆菌rpoB基因突变分子特征的研究文献。结果:36篇文献纳入研究,5 136株利福平敏感结核杆菌rpoB基因RRDR序列信息得以分析,38株(0.74%)rpoB基因RRDR序列呈现基因突变,涉及8个位点,分别为511(11株)、533(7株)、531(6株)、526(5株)、516(4株)、518(2株)、519(2株)、521(2株)等,其中1株涉及511/526双位点。结论:我国结核杆菌rpoB基因RRDR序列存在沉默突变现象,并非所有RRDR序列改变均与结核杆菌利福平药物敏感性有关。
文摘目的利用毕赤酵母高效表达人组织因子途径抑制因子(TFPI)。方法利用基因定点突变技术对人TFPIcDNA特定序列进行定点突变(同义突变)。将获得的突变体及野生型cDNA分别插入表达载体pPic9中,转化酵母宿主菌GS115和KM71,用0.5%的甲醇诱导重组蛋白表达。细胞培养上清经超滤浓缩后,依次用DEAE-sepharose Fast Flow、Heparin-sepharose CL6B及Sephadex G-75柱层析分离纯化得到重组蛋白,分别采用凝胶扫描成像定量分析和底物显色法测定重组蛋白的表达量和活性。结果凝胶扫描成像定量分析显示,同义突变体的表达量(1mg/L)显著高于天然型(0.1mg/L)。活性测定表明GS115重组菌在诱导表达12h后即可于培养上清中检测到TFPI活性,36h达峰值;而KM71重组菌诱导表达24h后才开始于培养上清中检测到TFPI活性,72h达峰值。两个菌株中突变体mTFPI-pPic9转化子的表达量均显著高于TFPI-pPic9转化子。重组蛋白相对分子质量约为42000。结论对TFPI-cDNA特定序列进行同义突变后能显著提高重组蛋白在毕赤酵母细胞中的表达,且显著高于在酿酒酵母和昆虫细胞的表达;重组蛋白具有良好的生物活性。因此,利用毕赤酵母表达TFPI是一种较好的选择。
文摘An inhabitant of north western Himalayan region and a gynodioceious plant having a lot of medicinal properties, Valeriana jatamansi Jones (Valerianaceae) is an enlisted endangered plant in the world. It was introduced in the research station of North Bengal Agricultural University (27.06°N 88.47°E) situated in north eastern Himalayan region of Darjeeling district in the state of West Bengal from Sikkim Sangtok (27°25'N 88°31'E) of north Sikkim area in India for the purpose of conservation. As we noticed some irregular development of floral organs, we investigated some pertinent questions regarding ecological aberrations found in plants. We found plants introduced in north eastern Himalayan region changed their homology of number flower petals and position of stamens seen naturally in north western Himalayan region as per the reports. Was there any genetic or extreme environmental stress condition caused a sudden change in floral structure as it is generally known as a rare phenomenon and frequently not seen? What were the correlations of different floral parts and fitness of population in different morphotypes? We predicted possible outcomes of seed setting by univariate regression models in a particular environment in addition to this investigation. We proposed three models of heterozygousity for answering the reasons of unstable floral form from a general known floral form, where silent mutations help the plants to survive in adverse conditions in spite of deformed or variable formed of floral morphology.
文摘A silent mutation or sequence polymorphism, A to T substitution at codon 399 in exon11 of the PAH gene from a Chinese PKU patient, was found by sequence analysis. The fre-quencies of this new mutation in normal and abnormal (PKU) genes were 0.005 and 0.09,respectively, based on the analyses of 100 normal individuals and 39 PKU patients usingDNA amplification with polymerase chain reaction (PCR) and oligonucleotide hybridizationmethods. This silent mutation can be used as a "genetic marker" for PKU prenatal diagno-sis. Recently, a fetus at risk for PKU, who could not be completely predicted by RFLPslinkage analysis, was prenatally diagnosed with this genetic marker.
