MOLECULAR CLONING AND NUCLEOTIDE SEQUENCE ANALYSIS OF A TRANSFORMING GENE FROM HUMAN GASTROCARCINOMA CELL LINE

Mouse and rat fibroblasts were transfected with total DNA from human gastrocarcinoma cell line BGC-823. It was shown by hybridization assay that the genome of one of the rat secondary foci contains transforming genes from the human gastrocarcinoma cell line, which are homologous to the protooncogene c-Ha-ras in the normal cells. The genomic library of the rat secondary foci was constructed, using λ phage EMBL3 as the vector. The transforming gene Ha-ras of the human gastrocarcinoma cell was thus cloned by screening the library with the probes of human Alu repeat sequence and c-Ha-ras. The nucleotide sequences of the first and second exons were analysed by M13-dideoxy method. The result shows that the nucleotide sequence of the transforming gene is the same as that of the normal protooncogene except one nucleotide difference in the first exon.     

Nucleotide Sequence of a Cloned Human HBV Mutant (pDKHBV) in Duck Hepatoma of Qidong County

This is the first report to describe the presence of an HBV-like DNA sequence in two hepatoma and their tumor surrounding liver tissues, one precancerous and one non-malignant liver tissue of ducks collected from Qidong County of China. The HBV-like sequences were either in an episomal form of 3.2 kb or in an integrated form of various sizes, while the DHBV DNA sequences (3.0 kb) were either present or absent in these tissues and in different size pattern. Furthermore, there was no evidence of cross-hybridization between HBV-like DNA sequences in duck and DHBV DNA. A 3.2 kb HBV-like DNA sequence has been cloned from one duck hepatoma (40 K), designated as pDKHBV. The 3218 bp full-length nucleotide sequence of this clone has been determined, which had no apparent homology with Duck Hepatitis B Virus (DHBV) genome, but was highly homologous to human HBV adw_2 subtype (99.0%). The sequence was composed of four open reading frames for HBV gene Pre-S/S, X, C and P respectively. In addition to multiple sites     

Amino Acid Sequence of an Excitatory Insect-selective Toxin (BmK IT) From Venom of the Scorpion Buthus martensi Karsch

The insect-selective neurotoxin(BmK IT) of scorpion Buthus martensi Karsch was first reduced and S-alkylated, and then digested by TPCK-trypsin and Staphylococcus aureus V-8 Protease. The enzymatic peptides were purified on TLC-plastic sheet and submitted to determine their amino acid compositions and sequences. The sequence of the 70 amino acid residues of BmK IT was established with reference to the primary structure of AaH IT, another excitatory insect-selective toxin from the venom of North African scorpion Androctonus australis Hector. About 75% of the homologous sequence was found in the molecules of BmK IT and AaH IT. It is obvious that the results contribute toward better understanding of the molecular structure characteristics, structure/activity relationship of scorpion insect-selective toxins, and they can serve as the molecular basis for utilizing the toxins as a tool to clarify molecular mechanism involved in channel gating, and to infer the possibility of developing them as new selective b     

Simultaneous electrochemical DNA hybridization assay for PAT and FMV 35S gene sequence using quantum dots as labels

An electrochemical method for the simultaneous detection of two different DNA sequences from PAT and FMV 35S gene sequence using CdS and PbS quantum dots （QDs） as labels was described. The QDs were readily functionalized with oligonucleotides as electrochemical DNA probes and selectively hybridized to the complementary sequences immobilized on the microplate. The QDs anchored on the hybrids were dissolved in the solution by the oxidation of HNO3 and further detected by a sensitive differential pulse anodic stripping voltammetric method （DPASV）. The DPASV signals of the oxidation of Cd^2＋ and Pb^2＋ ions present in the solution were different and reflected the identity of corresponding ssDNA targets sequences.     

An analysis of fractal geometry of macromolecular gelation

With fractal geometry theory and based on experiments, an analysis of fractal geometry behavior of gelation of macromolecules was carried out. Using the cross-linking copolymerization of styrene-divinylbenzene (DVB) as an example, through the determinations of the evolution of the molecular weight, size and the dependence of scattering intensity on the angle of macromolecules by employing laser and synchrotron small angle X-ray scattering, respectively, this chemical reaction was described quantitatively, its fractal behavior was analyzed and the fractal dimension was also measured. By avoiding the complex theories on gelation, this approach is based on modern physical techniques and theories to perform the analysis of the behavior of fractal geometry of macromolecular gelation and thus is able to reveal the rules of this kind of complicated gelation more essentially and profoundly.     

CLONING AND ANALYSIS OF HISTONE 3 GENE AND RUBISCO SMALL SUBUNIT GENE OF RICE

We have isolated and determined the DNA sequence of several genes from the nucleus of rice (Oryza sativa, IR26). We screened a genomic library of rice IR26 and isolated a 14.8 kb segment containing an H3 gene and an H3-like pseudogene. Sequence analysis showed that the coding sequence of the rice H3 gene is 405 bp in length, and the 5' and 3' noncoding regions contain several regulatory sequences common to eukaryotic or histone genes. The codon usage of the rice H3 gene is highly unusual in that the third codon position is 98% G and C. Southern blotting analysis suggested that the copy number of the H3 gene is around 50 per diploid rice genuine. From the same rice geaomic library, we have identified rbcS, which codes for the small subunit of ribulose-1, 5-bisphosphate carboxylase-oxygenase (Rubisco). The rbcS sequence is interrupted by an intron at the same location in both rice and wheat. The first 18 amino acids of the transit peptide in rice and wheat rbcS are identical     

STUDIES ON CHARGE TRANSFER POLYMERIZATION——POLYMERIZATION OF ACRYLONITRILE INITIATED WITH PHENYL HYDRAZINE AND ITS DERIVATIVES

The photopolymerization of acrylonitrile (AN) initiated with phenyl hydrazine (PHZ) and its derivatives has been studied. The initiator exponent and monomer exponent were determined from the kinetic investigation to be 0.66th and 2.1th respectively and the overall activation energy was 33.4KJ/mol for the PHZ-AN system. Spectral analysis and other data indicate that a charge transfer complex between PHZ as a donor and AN as an aceeptor is formed. The initiation mechanism was proposed.     

MOLECULAR CHARACTERIZATION OF RICE Wx GENE

The complete nucleotide (nt) sequence of the rice waxy(Wx) gene, which is responsible for the synthesis of amylose in endosperm and pollen, has been determined by a combination of restriction mapping and nt sequence analysis of two overlapping genomic DNA clones. The entire gene is about 5.5 kb in length. The alignment of the nt sequence of the Wx gene from rice with those of maize (Klsgen, R. B. et al.) and barley (Rohde, W. et al.) revealed the presence of thirteen introns and fourteen exons. The full-length of Wx protein in cluding transit peptide is 609 amino acid (aa) residues. The calculated molecular weight of rice Wx preprotein is about 72 kD. There is no significant difference between the similarity scores of the aa sequence deduced from the rice Wx gene compared with those of maize and barley. However, the nt sequences of the 5'-end upstream, 3'-end downstream and introns of the rice Wx gene, as well as the aa sequence of the transit peptide region of the Wx preprotein have low similarity scor     

RETROVIRUS MEDIATED TRANSFER OF ANTISENSE HUMAN c-myc GENE INTO HUMAN ESOPHAGEAL CANCER CELLS SUPPRESSED CELL PROLIFERATION AND MALIGNANCY

A retroviral vector, called pDAM3, containing the neomycin resistant gene and the antisense human c-myc gene fragment (the third exon and 3'flanking sequence) was constructed. pDAM3 was introduced into amphotropic packaging cells PA317 by the calcium phosphate precipitation method. Several G418-resistant PA317 clones were isolated. The virus titer of these cell lines was determined by infectivity of their cuhure fluid to NIH/3T3 cells. The highest titer obtained was 8×10~5 G418-resistant colony forming units/ml. Clonal and pooled G418-resistant PA317 colonies with high titers were expanded and analyzed by Southern blot for the presence of intact viral sequences. All cell lines were found to harbor the internal sequences of the pDAM3 vector without any rearrangement. Recombinant virus DAM3 infected human esophageal cancer cell line EC8712 efficiently. The DAM3-infected EC8712 (called EC-DAM3) was found to contain the full DAM3 sequence (4.8kb) by Southern blot analysis. Antisense myc RNA expressed in th     

用墨西哥帽小波研究DNA序列的分形特征

结合小波分析和分形理论，采用分数布朗运动(FBM)建立数学模型，研究脱氧 核糖核酸(DNA)序列的自相似性。用DNA walk的方式将DNA序列表达成为一个数字信 号，通过不同小波变换的尺度对应不同特征长度的碱基，选择墨西哥帽小波为母小 波，进行实验考察，结果发现小波系数的图形在许多尺度看上去很相似，大尺度对 应较多的碱基(小波变换尺度为2^7时，对应512个碱基)，能看到概貌；小尺度对应 较少的碱基(小波变换尺度为2^3时，对应32个碱基)，可看到细节。这表明其DNA序 列中存在分形结构，可以用分维数来作为定量描述。这种算法为进一步研究与基因 序列自相似结构有关的基因进化信息提供一种选择的途径。     

Origin and evolution of exon/intron junctions

In nuclear mRNA genes, exon/intron junctions (both exon/intron and intron/exon junctions in this paper) possess the specific duplex pattern with the corresponding ends (3′ to 3′, 5′ to 5′) of exons and introns more or less identical. In genes with group I or group II introns, overall analyses indicate there are also related patterns in their exon/intron junctions. From the analysis of these specific regions of split genes and the study of the composition of primitive genomes, it is proposed that the sequences of primitive exons and introns are identical at least in their corresponding boundary regions. And more fundamentally, it may be concluded that exon/intron junctions were originally related to tandem repeated sequences in the earliest genomes. Results from a preliminary analysis of specific motifs in modern repeated sequences support such a view on the origin of exon/intron junctions. As for the evolution of exon/intron junctions, there have been multiple rather than single paths.     

DNA中编码序列的分形特征研究

随着基因组数据库的日益增大，如何从这庞大的数据库中提取有用的信息已成为全世界科学家迫在眉睫的难题。本文运用网格维数分别刻画了60个人类基因序列编码区的分形特征。研究结果表明：在同一个基因中，外显子的维数一般要大于整个蛋白质编码序列的维数，并通过对比随机序列的网格维数，证实了这一结论。结合分形理论及功率谱研究可以得出，具有较少外显子的基因，外显子中包含有较多的遗传信息，而对于较多外显子的基因则相反，遗传信息可能储存于内含子中。这些结论对内含子功能以及DNA序列的复杂性的研究具有一定的理论意义和实用价值。     

红外光谱的分形特征

红外光谱可作为一种信号的功率谱,用富里叶分析来研究。同时,红外光谱的吸收峰并不是随频率呈周期性变化的,而是表现出一些混沌特征,因此其分子的振动随时间的变化,可看成一种混沌运动,其运动轨迹可能具有某种分形结构。因此,可用分形理论来研究分子的振动。本文把富里叶分析与分形理论结合起来,从整体的角度对红外光谱的分形特征作一些尝试性的探讨。     

Fractal analysis of polyethylene catalysts surface morphologies based on wavelet transform modulus maxima method

Surface morphologies of supported polyethylene (PE) catalysts are investigated by an approach combining fractal with wavelet. The multiscale edge (detail) pictures of catalyst surface are extracted by wavelet transform modulus maxima (WTMM) method. And, the distribution of edge points on the edge image at every scale is studied with fractal and multifractal method. Furthermore, the singularity intensity distribution of edge points in the PE catalyst is analyzed by multifractal spectrum based on WTMM. The results reveal that the fractal dimension values and multifractal spectrums of edge images at small scales have a good relation with the activity and surface morphology of PE catalyst. Meanwhile the catalyst exhibiting the higher activity shows the wider singular strength span of multifractal spectrum based on WTMM, as well as the more edge points with the higher singular intensity. The research on catalyst surface morphology with hybrid fractal and wavelet method exerts the superiorities of wavelet and fractal theories and offers a thought for studying solid surfaces morphologies. Supported by the Chinese Petroleum & Chemical Corporation Development Department (Grant No. x504024)     

中药色谱指纹图谱的小波变换及分形表达方法

提出一种基于小波变换的色谱指纹图谱分形表达方法。该法运用小波变换将色谱谱线分解至不同分辨尺度，然后计算各尺度分量的分形维数，用色谱的小波基分形参量替代色谱指纹图谱的采样值。仿真实验结果表明，色谱小波基分形参量对谱峰保留时间漂移具有较好的抗干扰能力。以当归和川芎两种中药材的品种及道地性鉴别分类问题为实例，比较研究色谱采样值与小波基分形参量，k-近邻法的交叉验证计算结果表明，小波基分形参量的分类效果优于色谱采样值。     

Multiplexed identification of different fish species by detection of parvalbumin, a common fish allergen gene: a DNA application of multi-analyte profiling (xMAP™) technology

Fish are a common cause of allergic reactions associated with food consumption, with parvalbumin being the major allergenic protein. Some fish-hypersensitive patients tolerate some fish species while being allergic to others. Reliable detection methods for allergenic fish species in foods are necessary to ensure compliance with food allergen labeling guidelines to protect fish-allergic consumers. The objective of this project was to develop a multi-analyte detection method for the presence of fish in food. Therefore, conserved parvalbumin exon sequences were utilized for the design of universal PCR primers amplifying intron DNA and small regions of exons flanking the enclosed intron from even very distantly related fish species. An assay for the identification of eight fish species was developed using xMAP™ technology with probes targeting species-specific parvalbumin intron regions. Additionally, a universal fish probe was designed targeting a highly conserved exon region located between the intron and the reverse primer region. The universal fish assay showed no cross-reactivity with other species, such as beef, pork, lamb, chicken, turkey, and shrimp. Importantly, with the exception of one notable case with fish in the same subfamily, species-specific detection showed no cross-reactivity with other fish species. Limits of detection for these eight species were experimentally estimated to range from 0.01% to 0.04%, with potential to increase the detection sensitivity. This report introduces a newly developed method for the multiplex identification of at least eight allergenic fish species in food, which could conceivably be extended to detect up to 100 species simultaneously in one sample.