毛白杨乙酰-乙酰载体蛋白硫脂酶基因(PtFATB)的克隆与表达分析

植物脂肪酸合成的主要部位是叶绿体,叶绿体向外运输脂肪酸的种类和数量受到乙酰-乙酰载体蛋白硫脂酶(FATB)控制。FATB基因在植物生长过程起着非常关键的作用。本研究以毛白杨为材料,将生物信息学知识和分子生物学手段相结合,首先利用现有的杨树基因组EST序列库资源,通过同源序列搜索,经过多次拼接合并获得了理论的杨树脂肪酸去饱和酶基因PtFATB序列全长,利用RT-PCR手段成功克隆得到了毛白杨FATB基因全长编码序列cDNA,该cDNA全长1,450bp,包括起始密码子ATG和144bp的5′末端非编码区,终止密码子TGA和40bp的3′末端非编码区,开放阅读框编码421个氨基酸。通过RT-PCR半定量研究了PtFATB在叶片组织中的表达量最高,茎、根中的表达量依次降低。在低温、干旱、NaCl、ABA四种条件下诱导生长24h,只有在低温的条件下发现PtFATB表达量略微降低,其他几种情况未有变化,该结果表明PtFATB呈组成型表达。上述结果为植物脂肪酸的基因工程提供了基础。     

Alterations of gene expression profiles induced by sulfur dioxide in rat lungs

Sulfur dioxide (SO2) is a ubiquitous air pollutant presents in low concentrations in urban air and in higher concentrations in working environment.Few data are avail-able on the effects of being exposed to this pollutant on the molecular mechanism,although some biochemical changes in lipid metabolism,intermediary metabolism and oxidative stress have been detected.The present investigation aimed at analyzing the gene expression profiles of the lungs of Wistar rats short-term (20 ppm,6 h/day,for seven days) and long.term (5 ppm,1 h/day,for 30 days) exposed to SO2 by Affymetrix GeneChip (RAE230A) analysis.It was found that 31 genes,containing 18 known genes and 13 novel genes were up-regulated,and 31 genes,containing 20 known genes and 11 novel genes,were down-regulated in rats short-term exposed to SO2 compared with control rats.While there were 176 genes,containing 82 known genes and 94 novel genes were up-regulated,and 85 genes,containing 46 known genes and 39 novel genes,were down-regulated in rats long-term exposed to SO2 compared with control rats.It is suggested that:(1) SO2 exerts its effects by different mechanisms in vivo at high-dose short-term inhalation and at low-dose long-term inhalation;(2) a notable feature of the gene expression profile was the decreased expression of genes related to oxidative phosphorylation in lungs of rats short-term exposed to SO2,which shows high-dose short-term exposed to SO2 may cause the deterioration of mitochondrial functions;(3)discriminating genes in lungs of rats long-term exposed to SO2 included those involved in fatty acid metabolism,immune,inflammatory,oxidative stress,oncogene,tumor suppresser and extracellular matrix.The mechanism of low-dose long-term exposed to SO2 is more complex.     

The effect of Cyclosporine A on cardiomyocytes differentiation

Cyclosporine A (CsA) is a powerful immunosuppressive drug which significantly improved the success of organ transplantation; however, the major limiting factors for the drug's clinical use are its long and short term adverse effects. The present study was conducted to examine, in a dose-dependent manner, in a model of cardiogenesis, the effect of CsA on cardiomyocytes differentiation.     

Identification of functional candidate genes for drought tolerance in rice

Drought tolerance (DT) in rice is known to be controlled by many quantitative trait loci (QTLs) and involved differential expression of large numbers of genes, but linking QTLs with their underlying genes remains the most challenging issue in plant molecular biology. To shed some light on this issue, differential gene expression in response to PEG simulated drought in 3 unique genetic materials (a lowland rice, IR64 and its derived line, PD86 which has 11 introgressed DT QTLs, and a upland rice IRAT109) was investigated using a PCR-based subtractive hybridization strategy. More than 300 unique subtracted cDNA sequences, covering genes of diverse cellular activities and functions, were identified and confirmed by semi-quantitative and quantitative RT-PCR. Detailed bioinformatics analyses of the data revealed two interesting results. First, the levels and mechanisms of DT of the three rice lines were associated with the number and types of differentially expressed genes, suggesting different DT mechanisms in rice are controlled by different sets of genes and different metabolic pathways, and most differentially expressed genes under drought were able to contribute to DT. Second, there appeared a high correspondence in genomic location between DT QTLs and clusters of differentially expressed genes in rice, suggesting some DT QTLs may represent clusters of co-regulated and functionally related genes. Thus, differential gene expression analyses using genetically characterized materials can provide additional insights into the molecular basis of QTLs and convergent evidence to shortlist the candidate genes for target QTLs. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Bin-Ying Fu and Jian-Hua Xiong are contributed to this work equally.     

H5N1禽流感病毒HA基因在昆虫细胞中的表达及生物活性鉴定

经RT-PCR扩增了H5N1亚型禽流感病毒血凝素基因(HA)片断,限制性内切酶酶切后将其克隆到pFastBacHTA杆状病毒转座载体,经酶切鉴定及测序,筛选出阳性重组转座载体pFastBac-H5。将pFastBacH5转化含有杆状病毒穿梭载体（bacmid）的DH10Bac感受态细胞,通过蓝白斑筛选和PCR鉴定获得重组杆状病毒穿梭载体rBacmid-H5。rBacmid-H5在脂质体介导下转染sf9昆虫细胞,SDS－PAGE蛋白电泳、Western blot、血凝试验和血凝抑制试验分析表明：分子量约63Kd重组血凝素蛋白（rH5）在sf9昆虫细胞中实现了高效表达。rH5具有血凝活性,而且其血凝活性能够被H5N1禽流感病毒高免血清所抑制;rH5免疫鸡诱导产生针对H5N1禽流感病毒亚型特异的血凝抑制抗体,说明表达的重组蛋白具有与天然蛋白相似的生物活性。     

A novel vector element providing multicopy vector integration in Arxula adeninivorans

An Arxula adeninivorans vector element has been identified that provides multicopy integration in an atrp1 host strain. The element consists of the ATRP1 selection marker fused to a newly generated truncated ALEU2 promoter of 53 bp. In the described example eight copies of an amyA expression vector encoding heterologous alpha-amylase from Bacillus amyloliquefaciens are integrated in the genome of the recombinant strain instead of a single copy observed when using the ATRP1 element with the complete promoter. The high copy number results in strains of superior productivity for a secreted recombinant alpha-amylase. The vector design enables the integration of a small vector fragment that consists of yeast DNA only providing high transformation frequencies and a high mitotic stability.