Detection of Tumor Necrosis Factor Gene by Piezoelectric Nucleic Acid Senosr

A piezoelectric nucleic acid sensor was constructed ofr detection of tumor necrosis factor gene.Two methods were employed for immobilization of nucleic acid probe on gold electrode of piezoelectric crystal.The results show that polyethyleneimine adbesion and glutaraldehyde cross-linking method has higher sensitivity,stability and selectivity than protein A method.The solid-phase nucleic acid hybridization of oligo unclecotides and tumor necrosis factor target gene sequence were monitorde using this sensor.Tumor necrosis factor gene sequence(580bp) was detected by this nucleic acid sensor for the first time.     

草原兔尾鼠透明带3(lZP3)基因序列同源性比较

透明带3作为精子的初级受体是透明带的一种主要糖蛋白,而抗ZP3抗体能够阻止精卵结合.因此,ZP3被认为是避孕疫苗的候选免疫原.草原兔尾鼠是新疆的重要害鼠,将它的ZP3基因序列与GenBank上已发表的几种鼠的ZP3基因序列进行同源性比较,将有助于哺乳动物受精机理的阐明与免疫不育疫苗的设计,同时也有助于了解这些鼠在系统进化中的相对地位.     

A Paleogenomic Algorithm for Reconstruction of Ancient Operons from Complete Microbial Genome Sequences

Operons, or co-transcribed and co-regulated contiguous sets of genes, in microbial genomes are poorly conserved across different genomes due to gene fusion, deletion, duplication and other genome shuffling processes. The currently available genomes are the results of numerous reshuf-     

草原兔尾鼠透明带3（IZP3）基因序列同源性比较

透明带3作为精子的初级受体是透明带的一种主要糖蛋白，而抗ZP3抗体能够阻止精卵结合．因此，ZP3被认为是避孕疫苗的候选免疫原．草原兔尾鼠是新疆的重要害鼠，将它的ZP3基因序列与GenBank上已发表的几种鼠的ZP3基因序列进行同源性比较，将有助于哺乳动物受精机理的阐明与免疫不育疫苗的设计。同时也有助于了解这些鼠在系统进化中的相对地位．     

基于线粒体细胞色素b基因序列的阿尔金山野生双峰驼分子系统发育研究

目前对于野生双峰驼作为一个独立种的有效性还有着较多争议．研究测定了2头阿尔金山野生双峰驼个体的线粒体细胞色素b基因序列，并结合已有的双峰驼细胞色素b基因序列进行了系统发育分析．结果表明：现有的双峰驼分为2个种群：新疆种群和甘肃种群；2个种群间的遗传距离为2．4％～3．0％，尚未达到种间水平；阿尔金山野生双峰驼属于新疆种群，不能作为一个独立的有效种．     

Characterizing Long—range Correlation Properties in Nucleotide Sequences

Using continuous wavelet transform as the analytical tool,the fractal characteristic of nucleotide sequences was studied.The fractal dimension of the exon and intron sequences for different species was calculated.We use the Mexican hat wavelet function as the mother wavelet and Hurst exponent describe the long-range correlation.It is found that the Hurst exponent of intron sequence is larger than of exon sequence for the same gene.     

Gene Sequence, Soluble Expression and Homologous Comparison of a D-Hydantoinase from Pseudomonas putida YZ-26

A 1440bp open-reading frame encoding D-hydantoinase from Pseudomonas putida YZ-26 was cloned and sequenced（ GenBank AY387829）. The DNA fragment was inserted into Nde and BamHI sites of vector pET-3a, yielding a recombinant plasmid, pET-HDT. After being transferred into the host strain, the artificial strain, pET-HDT/ E. coli BL21 can express the D-hydantoinase as the soluble form in the Lura-Bertani medium without addition of any inducers. The activity of the enzyme toward substrate DL-hydantoin can reach 3000-4000 IU per cells from one-liter bacterial culture incubated at 30 ℃ for 10-12 h. By the comparison of amino acid sequence homology, hydrophobic residues analysis and secondary structure prediction, it was found that D-hydantoinase reported herein is quite similar to that from Pseudomonas putdia CCRC12857, and alike to that from Pseudomonas putdia DSM84 or other bacteria. A rapid and efficient purification procedure of the enzyme was performed by a three-step procedure： ammonium sulfate fractionation, phenyl Sepharose hydrophobic interaction chromatography and Sephacryl S-200 gel filtration. The molecular mass of the monomeric enzyme is 52042 Da as determined by MALDI-TOF mass spectrometry.     

嗜盐古菌中氯视紫红质基因序列的遗传分析

采用PCR方法扩增了嗜盐古菌AB19、AB30和AJ5编码螺旋C至螺旋G的氯视紫红质（halorhodopsin，HR）蛋白基因片断和168rRNA基因（168rDNA），测定了它们的核苷酸序列，与已报道的，hr基因序列差异显著．获得AJ5 HR蛋白基因序列在Halobiforma属中尚属首次．对hr基因序列进行的遗传分析，包括GC含量、转换与颠换的比值、密码子使用偏好，表明hr基因面临进化选择和偏倚突变压的双重制约，是一类进化程度较高的基因．对比br基因编码蛋白螺旋C到G的序列发现它们具有相似的种属特征．采用BR和HR蛋白螺旋C到G序列构建系统发生树比传统的168rDNA序列具有优势，BR和HR可以作为两种新型的分子指标．     

基于非参数方法的DNA序列信噪比阈值研究

基于人类、鼠类及其他哺乳动物的基因数据,共计1264个外显子、1553个内含子进行基因预测,对DNA序列信噪比阈值进行判断.提出基于Mann-Whitney检验、符号检验、Wilcoxon符号秩和检验的非参数置信区间法计算信噪比阈值,得到人类的阈值为1.108,鼠类的为1.0971,其他哺乳动物的为1.1754,与均值平均法、带标准差加权平均法、定义阈值为2的方法比较判断的正确率,结果表明利用非参数置信区间法计算的阈值在基因预测中具有最高的正确率.