病毒性心肌疾病的基因时空表达特征

目的 研究病毒性心肌炎到扩张型心肌病全病程基因时空表达谱动力学特征.方法 用含有8 000个基因克隆的基因芯片检测CVB3反复感染Balb/c小鼠后第0,7,21天及第3,6,9个月心肌组织基因表达,并用SOM对差异性表达的基因进行聚类分析.结果（1）第10,14,15,19,20类基因在第7天时表达上调,第21,22类基因在第21天表达上调,而第23,24类基因在第7、21天表达均上调;（2）第6,7,11,12类基因在第7天时表达下调,第4,5类基因在第21天表达下调,而第2,3,8类基因则在第7,21天表达均下调;（3）第1,16类基因在第7天时表达下调,而第21天后则表现为上调;（4）有些基因如转移生长因子β结合蛋白、β-2微球蛋白,CD 53抗原却表现为持续性表达上调,而α-1微球蛋,ninjurin 1,舒血管素27,cytokine inducible SH2-containing protein 2则出现持续性表达下调.结论 建立了小鼠CVB病毒性心肌炎及扩张型心肌病全病程基因表达谱动力学模式,为进一步了解其分子发病机制提供全新的视野.     

宫颈癌组织差异表达基因的检测及分析

选取三例经分型明确为HPV16感染的宫颈癌病例,取癌组织(T)、癌旁组织(N)及远瘤正常宫颈组织(F)标本,用Roche NimbleGen芯片系统筛选出差异表达的基因并进行分析.三例标本中,癌组织与远瘤正常宫颈组织相比,差异表达基因共有673个,其中261个上调,412个下调;差异表达基因主要有原癌基因、抑癌基因、细胞信号转导、代谢、免疫应答、细胞受体、蛋白翻译合成有关基因等.     

Molecular evolution of scorpion a-toxins----Accelerated substitutions and functional divergence

Scorpion a-toxins are a family of toxic proteins with similar scaffold, but possess divergent pharmacological properties. Analysis of cDNA sequences reveals that the numbers of nucleotide substitutions per site ( K ) for 5' and 3' UTRs are smaller than those per synonymous site ( Ks) for the mature peptide-coding sequences, whereas the numbers of nucleotide substitutions per nonsynonymous site (-Ka) are close to or larger than Ks values for relevant pairs of cDNAs. These results, together with phylogenetic analysis, indicate that scorpion a-toxins have evolved by accelerated substitutions in the mature toxin regions. In addition, the 15 amino acids, absolutely conserved in all the scorpion a-toxins described so far. are mostly located in molecular interior, which may be involved in structural constraints for stabilizing the CSa(3 fold in evolution of these molecules. Four hot spot mutation sites in the molecular surface are found to distribute in the putative functional regions of a-toxins. suggesting that positive Darwinian selection drives the accelerated evolution of scorpion a-toxins. These findings reasonably explain the relationship between three-dimensional structure conservation and functional divergence of scorpion a-toxins and are of important value in guiding us in our engineering experiments to obtain higher affinity ligands to Na+ channels.     

胆固醇-7,8-脱氢酶大肠杆菌工程菌的构建

7-去氢胆固醇在化妆品和医药领域具有较大的应用需求,但现有的生产方法为化工法,流程复杂,且易污染环境.发酵法生产7-去氢胆固醇是一条新颖且具有潜在竞争力的生产途径.以虾Y-器官微粒体的cDNA文库为模板进行胆固醇-7,8-脱氢酶基因的扩增,与质粒载体连接后转化大肠杆菌,并对该工程菌的生物催化胆固醇-7,8-脱氢能力进行检测.     

波纹唇鱼神经肽Y基因的克隆及原核表达

以波纹唇鱼为实验对象,采用同源基因克隆技术和RACE技术得到神经肽Y基因的cDNA全长序列.波纹唇鱼npy的cDNA全长序列为645 bp,包含59 bp的5'UTR、300 bp的ORF和286 bp的3'UTR.分子进化的比对分析表明,波纹唇鱼NPY前体与斜带石斑鱼和锯隆头鱼的亲缘关系最近.波纹唇鱼ORF编码99个氨基酸,NPY前体多肽包括:信号肽、成熟肽、Gly-Lys-Arg翻译后加工位点和羧基末端侧翼肽段(CPON).该NPY前体的预测分子质量为11.27 kD,理论等电点为5.51.采用pET-32a(+)原核表达系统构建波纹唇鱼npy基因的原核表达重组子pET-32a(+)-NPY,并获得重组菌株.对重组蛋白表达菌株进行培养条件优化,结果表明:该菌株在30℃,0.6 mmol/L IPTG,培养时间8 h的条件下,重组蛋白的表达效率最高.