牦牛TGF-β2基因片段的克隆测序及系统进化分析

克隆测序了牦牛的TGF-β2基因,并进行了Blastn比较分析。结果表明,牦牛TGF-β2基因片段长为559bp,与普通牛、人、黑猩猩、小鼠的相应片段的同源性分别达98%、95%、94%、93%。在5′端调控区域没有类似TATA盒元件,推测TGF-β2基因在脾脏、肾脏组织细胞中表达量不是很高。由于TGF-β对细胞的生长、分化和免疫功能都有重要的调节作用,牦牛TGF-β2基因研究对高原畜牧业发展提供了科学资料。     

FSHβsubunit gene is associated with major gene controlling litter size in commercial pig breeds

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Synonymous Codon Usage Bias and Overexpression of a Synthetic Gene Encoding Interferon α2b in Yeast

To achieve higher level expression of Interferon α2b(IFN-α2b)in methylotrophic yeast(Pichia pastoris),a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P.pastoris and optimized G C content.The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA,and then integrated into P.pastoris GS115 genome by electroporation.Multi-copy integrants in the Mut recombinant P.pastoris strain were screened by high concentrations of Zeocin.120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods.In addition,Western blot analysis showed that the recombinant proteins had immunogenicity.The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/VSV system,which was 3.3×105 IU/mL.     

转染E1B55K基因提高Hep2细胞包装肠腺病毒Ad41的能力

人F组腺病毒Ad40、Ad41难以在体外培养的细胞中传代,被称为难养腺病毒(Fastidious adenovirus).本研究观察了在Hep2细胞表达Ad41 E1B55K基因对Ad41复制的促进作用.从Ad41阳性粪便标本中用PCR的方法获得E1B55K基因,构建真核表达载体,转染Hep2细胞,筛选单克隆,用RT-PCR检测了E1B55K基因的表达.用引起293细胞完全CPE比较产毒量的方法对所得细胞克隆进行初步筛选,获得一株产毒相对较强的细胞Hep2-E1B#4.与对照细胞Hep2、Hep2-DNA3相比,等量Ad41接种Hep2-E1B#4产生的细胞病变效应(CPE)程度明显加深.用免疫细胞化学的方法测定产毒的感染滴度,等量Ad41接种后,Hep2-E1B#4产生的子代腺病毒滴度大于对照的9倍;半定量PCR测得Hep2-E1B#4子代病毒基因组拷贝数约为对照细胞的4倍.结果说明转染E1B55K基因促进了Ad41在Hep2细胞的复制,获得的Hep2-E1B#4细胞株可用于Ad41的分离、培养和体外扩增.     

High expression of human clotting factor IX cDNA in myoblasts C2C12 cells and C3H mice

Mouse myoblast C2C12 cell was used as target cell for gene transfer study of human clotting factor IX (hFIX) cDNA. In addition to the previously constructed retroviral vectors XLIX, LNCIX and GINaCIX, GlNaMCIX with hFIX driven by muscle creatine kinase (MCK) enhancer and human cytomegalovirus (CMV) was constructed, based on the retroviral vector GINa. These four retroviral vectors were used to transduce mouse my-oblasts C2C12. With ELISA assays, it has been found that the expression levels of human clotting factor IX detected in those transduced C2C12 cells are GlNaMCIX>GlNaCIX> LNCIX>XLIX. Mixed colonal cells transduced with GlNaMCIX expressed hFIX protein at the level of 640 ng/106 cell every 24 h. The modified C2C12 cells transduced with GlNaMCIX were implanted into skeletal muscle of the hindlegs of C3H mice; a stable expression of hFIX was detected and lasted for 35 d, with a maximum level of 206 ng/mL plasma. The regulation of hFIX cDNA expression in myoblasts was discussed and it was strongly sug     

中国人群5-羟色胺2A受体基因中T102C多态性与精神分裂症的联系 Analysis of Association Between T102C Polymorphism in theSerotonin 2A Receptor Gene and Schizophrenia in Chinese Population

在研究5-羟色胺2A受体基因多态性与精神分裂症的关联分析中,调查了20 2例精神分裂症患者及202例正常对照。各相匹配组间比较未发现基因型和等位基因频率的显著性差异。结果提示,在中国人群中5-羟色胺2A受体的静态T102C突变与精神分裂症之间不存在关联。 Abstract:Association study between in the T102C polymorphism serotonin 2A receptor gene and schizoprenia was performed in 202 schizophrenics and 202 normal controls.No significant differences of genotype and allele frequencies between the matched groups were found.Our results,which are different from some other studies,excluded the association between a silent T102C change and schizophrenia in the Chinese population.     

λN gene expression regulated by translation termination in ribosome L24 mutant

Although the initiation and elongation steps of protein synthesis have been extensively char-acterized in Escherichia coli (E. coli), the translation termination is still less well understood. However, recent experiment result might have provided some hints for our deeper understanding of the termination mechanism. (i) Not only does the translation stop codon act as a signal for ter-mination, but also its context influences the translation termination[13]; (ii) the structure similar-ity betwee…     

核转录因子PPARγ2的研究进展

过氧化物酶增殖物激活受体γ2(PPARγ2)是一个转录因子,属于核受体超家族的成员之一。其主要在脂肪组织表达,对脂肪细胞分化进行调控。其常见多态性Pro12Ala已发现与肥胖及2型糖尿病关系密切。它也是治疗糖尿病药物噻唑烷二酮类药物（TZDs）作用的靶分子。因此,对其进行代谢调控分子机制的研究,可能有助于对2型糖尿病预防或治疗中起作用的新药物靶位点的发现。 Abstract:Peroxisome proliferator-actived receptor γ2(PPARγ2) is a translation factor that belongs to the superfamily of nuclear receptors.It expresses predominantely in adipose tissue and has a key role in adipocyte differentiation.The common Pro12Ala polymorphism is associated closely with obesity and type 2 diabetes.It is the target molecular of thiazolidinediones which is a novel class of insulin sensitizer.The study of PPARγ2 molecular mechanism of metabolism control may accelerate the finding of new drug targets in prevention and therapeution of type 2 diabetes.     

Analysis and validation of genome-specific DNA variations in 5′ flanking conserved sequences of wheat low-molecular-weight glutenin subunit genes

Glutenins and gliadins are the main components of the wheat storage proteins and make up almost of the proteins found in gluten. Glutenins are polymeric pro-teins whose subunits are held together by in-ter-molecular disulphide bonds. They mainly consist o…     

Strand-biased Gene Distribution in Bacteria Is Related to both Horizontal Gene Transfer and Strand-biased Nucleotide Composition

Although strand-biased gene distribution(SGD) was described some two decades ago,the underlying molecular mechanisms and their relationship remain elusive.Its facets include,but are not limited to,the degree of biases,the strand-preference of genes,and the influence of background nucleotide composition variations.Using a dataset composed of 364 non-redundant bacterial genomes,we sought to illustrate our current understanding of SGD.First,when we divided the collection of bacterial genomes into non-polC and polC groups according to their possession of DnaE isoforms that correlate closely with taxonomy,the SGD of the polC group stood out more significantly than that of the non-polC group.Second,when examining horizontal gene transfer,coupled with gene functional conservation(essentiality) and expressivity(level of expression),we realized that they all contributed to SGD.Third,we further demonstrated a weaker G-dominance on the leading strand of the non-polC group but strong purine dominance(both G and A) on the leading strand of the polC group.We propose that strand-biased nucleotide composition plays a decisive role for SGD since the polC-bearing genomes are not only AT-rich but also have pronounced purine-rich leading strands,and we believe that a special mutation spectrum that leads to a strong purine asymmetry and a strong strand-biased nucleotide composition coupled with functional selections for genes and their functions are both at work.     

Interactions between HMG proteins and the core sequence of DNaseI hypersensitive site 2 in the locus control region (LCR) of the human β-like globin gene cluster

HMG proteins are abundant chromosomal non-histone proteins. It has been suggested that the HMG proteins may play an important role in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the core DNA sequence of DNaseI hypersensitive site 2 (HS2core DNA sequence, -10681--10970 bp) in the locus control region (LCR) of the human b-like globin gene cluster has been examined by using both the in vitro nucleosome reconstitution and the gel mobility shift assays. Here we show that HMG1/2 can bind to the naked HS2core DNA sequence, however, HMG14/17 cannot. Using the in vitro nucleosome reconstitution we demonstrate that HMG14/17 can bind to the HS2core DNA sequence which is assembled into nucleosomes with the core histone octamer transferred from chicken erythrocytes. In contrast, HMG1/2 cannot bind to the nucleosomes reconstituted in vitro with the HS2core DNA sequence. These results indicate that the binding patterns between HMG proteins and the HS2core DNA sequence which exists in different states (the naked DNA or the in vitro reconstituted nucleosomal DNA) are quite different. We speculate that HMG proteins might play a critical role in the regulation of the human β-like globin gene's expression.     

高低转移肺腺癌细胞系Anip973和AGZY83-a中P21过表达的研究

为探讨肿瘤抑制基因对肺腺癌细胞生长的抑制作用,利用FuGene转染方法将 P21基因的表达质粒转入一对分别具高、低转移能力的肺腺癌细胞系An ip973和AGZY83-a中。对p21蛋白过表达的细胞系进行了细胞生长曲线,克隆形成率,原位末端标记分析和流式细胞仪分析。p21蛋白过表达的一对细胞系细胞生长曲线斜率降低,克隆形成能力下降并出现明显的G1期阻滞,但未检测到凋亡信号。结果表明p21基因的过表达通过G1期阻滞抑制这一对肺腺癌细胞的生长,P21基因可以作为肺腺癌基因治疗的候选基因。 Abstract:In order to investigate the suppression effect of tumor suppressor genes in lung adenocarcinoma,we transfected P21 expression vector into a pair of lung adenocarcinoma cell lines with different metastasis potential:Anip973(high metastasis potential)and AGZY83-a(low metastasis potential).The suppression effects of p21 were evaluated by cell growth curve,cloning efficiency assay,flow cytometric analysis and Tunel technique.We found that increased expression of p21 in both cell lines was associated with significant lengthening of G1 phase,decreased proliferation potential and decreased cloning efficiency.No apoptosis was found in the cell lines with overexpressed P21 gene.The results showed that increased expression of P21 gene suppressed the lung adenocarcinoma cells by G1 arrest and P21 gene proved a candidate gene in lung adenocarcinoma gene therapy.     

猪瘟病毒结构蛋白E^ms在E．coli中的高效表达及纯化

猪瘟（Classical swine fever,CSF）是由猪瘟病毒（Classical swine fever virus,CSFV）引起的猪的高度接触性传染病,是严重危害养猪业的传染病之一。CSFV基因组为单股正链RNA分子,长约12．3kb,仅编码一个开放性阅读框。位于5’端的囊膜糖蛋白E^ms、E1和E2构成了CSFV的外壳,     

Effects of 1,2,4,6-<Emphasis Type="Italic">tetra</Emphasis>-O-galloyl-β-D-glucose from <Emphasis Type="Italic">P. emblica</Emphasis> on HBsAg and HBeAg secretion in HepG2.2.15 cell culture

A polyphenolic compound, 1,2,4,6-tetra-O-galloyl-β-D-glucose (1246TGG), was isolated from the traditional Chinese medicine Phyllanthus emblica L. (Euphorbiaceae) and assayed for its potential as an anti-hepatitis B virus (HBV) agent. The cytotoxicity of 1246TGG on HepG2.2.15 as well as HepG2 cells was determined by observing cytopathic effects, and the effects of 1246TGG on secretion of HBsAg and HBeAg in HepG2.2.15 cells were assayed by enzyme immunoassay. Results indicates that treatment with 1246TGG (6.25 μg/mL, 3.13 μg/mL), reduced both HBsAg and HBeAg levels in culture supernatant, yet the inhibitory effects tend to decline with the assay time. This study provides a basis for further investigation of the anti-HBV activity and possible mechanism of action of 1246TGG.     

Interactions between HMG proteins and the core sequence of DNaseI hypersensitive site 2 in the locus control region (LCR) of the human β-Mike globin gene cluster

HMG proteins are abundant chromosomal non-histone proteins. It has been suggested that the HMG proteins may play an important role in the structure and function of chromatin. In the present study, the binding of HMG proteins (HMG1/2 and HMG14/17) to the core DNA sequence of DNasel hypersensitive site 2 (HS2core DNA sequence, -10681-10970 bp) in the locus control region (LCR) of the human β-like globin gene cluster has been examined by using both the in vitro nucleosome reconstitution and the gel mobility shift assays. Here we show that HMG1/2 can bind to the naked HS2core DNA sequence, however, HMG 14/17 cannot. Using the in vitro nucleosome reconstitution we demonstrate that HMG14/17 can bind to the HS2core DNA sequence which is assembled into nucleosomes with the core histone octamer transferred from chicken erythrocytes. In contrast, HMG 1/2 cannot bind to the nucleosomes reconstituted in vitro with the HS2core DNA sequence. These results indicate that the binding patterns between HMG proteins and t     

2型腺相关病毒转导人胎肝造血细胞及其介导的β珠蛋白基因的表达

β地中海贫血是一种因β珠蛋白基因缺陷导致的遗传性贫血性疾病,基因治疗是唯一有望治愈该病的方法.2型腺相关病毒(adeno-associated virustype2,AAV2)是一种非致病性病毒,作为一种基因治疗载体,其应用潜力日益受到关注.目前还未见AAV2转导人早期胎肝造血细胞及其介导β珠蛋白基因在动物体内表达的实验报道.有研究表明,AAV2转导人造血干细胞的效率,因各实验室包装和纯化rAAV2的方法不同而存在差异,其中辅助病毒的污染被认为是一重要原因.制备了无辅助病毒污染的rAAV2,经体外检测其滴度,纯度及功能后,再转导人早期胎肝造血细胞,将被转导的胎肝造血细胞移植入受亚致死量剂量照射的8只BALB/C裸鼠体内,检测rAAV2介导的β珠蛋白基因在裸鼠体内的表达.结果显示:制备的无辅助病毒污染的rAAV2具有较高的滴度、纯度,并能够在体外介导β基因的表达;在8只受试BALB/C裸鼠中,RT-PCR在2只BALB/C裸鼠骨髓中检测到β珠蛋白基因的表达.提示,rAAV2能够转导人早期胎肝细胞并介导β珠蛋白基因的表达,但同时也存在表达量较低的缺点,应用于β地中海贫血的基因治疗还需要对AAV2生物学特性做深入的研究.     

Effects of external stimuli on the pacemaker function of the sinoatrial node in sodium channel gene mutations models

Loss of function and gain of function mutations of the sodium channel were investigated using an intact two-dimensional rabbit sinoatrial node (SAN) and atrial cell model. The effects of three external stimuli (acetylcholine secretion by the vagal nerve, acid-base concentration, and tissue temperature) on cardiac pacemaker function and conduction were studied. Our results show that these two groups of mutations have different effects on pacemaker function and conduction. Furthermore, we found that the negative effects of these mutations could be altered by external stimuli. The bradycardic effects of mutations were magnified by an increase in acetylcholine level. Changes in acid-base concentration and tissue temperature increased the ability of the SAN to recover its pacemaker function. The results of this study increase our understanding of sodium channel disorders, and help to advance research on the treatment of these conditions.