环境因素调控鼠疫耶尔森氏菌基因表达的比较转录谱学研究

发布时间：2018-05-19 10:05

本文选题：鼠疫耶尔森氏菌 + 转录调控　；参考：《中国人民解放军军事医学科学院》2005年博士论文

【摘要】：鼠疫是一种古老的自然疫源性疾病,其病原菌鼠疫耶尔森氏菌(以下简称鼠疫菌)是多宿主寄生菌,体现在:鼠疫菌以蚤类为传播媒介寄居在特定的宿主(主要是啮齿动物),并在自然界宿主中造成鼠疫疫情的周期性爆发,该过程中偶然与患畜接触或被带菌跳蚤叮咬而感染到人。鼠疫菌感染机体早期能在巨噬细胞内存活并繁殖,目前认为巨噬细胞内存活与繁殖获得致病能力是鼠疫菌得以最终致病的关键阶段。面对上述复杂的环境因素,鼠疫菌必须能够感应并快速适应每个环节的环境变化,才能最终在宿主体内存活和在自然界中传播并最终致病,而每个适应性反应也必然伴随着鼠疫菌基因转录改变。依据上述传播和感染过程中鼠疫菌可能面临的胁迫环境,我们设计并实施了多个体外模拟刺激条件的转录谱分析,包括温度(生长温度、冷休克和热休克)、渗透压(高盐、高渗和OmpR调控元)、H_2O_2(H_2O2刺激元和OxyR调控元)、低镁(低镁刺激元和PhoP调控元)等刺激因素。经过全基因组DNA芯片单个体外条件的转录谱分析,我们分别得到了本研究多个体外条件下鼠疫菌在细胞代谢和毒力等方面的特征转录谱。野生株与突变株的比较转录谱分析得到鼠疫菌调节蛋白OmpR、OxyR和PhoP在特定条件下可能调节的基因,为今后调节网络的研究提供调控元的靶标基因。更重要的是,我们将上述转录谱以及目前本实验室所有的体外条件转录谱结果中各个基因的转录数据进行汇总,归纳总结了目前已知毒力相关基因在本研究体外条件的转录规律,丰富了现有关于毒力相关基因的研究成果;通过聚类分析,并利用统计学分析方法对鼠疫菌基因组内在多个条件下共转录的基因或基因簇进行分析,最终预测了鼠疫菌基因组中39个可能的操纵子;根据聚类分析结果,结合基因组序列和注释信息,对部分基因和操纵子的功能进行预测。上述结果为鼠疫菌基因转录调控网络的构建及某些基因功能的预测提供了部分实验证据,有助于深入认识鼠疫菌的致病性及宿主-细菌间相互作用。
[Abstract]:Yersinia pestis is an ancient natural disease. Yersinia pestis (hereinafter referred to as Yersinia pestis) is a multi-host parasite. This is reflected in the fact that Yersinia pestis live in specific hosts (mainly rodents) with fleas as a vector of transmission, and cause periodic outbreaks of plague in natural hosts. This process occasionally contacts with infected animals or is infected with humans by the bite of bacterial fleas. Yersinia pestis can survive and reproduce in macrophages in the early stage of infection. At present, it is considered that survival and reproduction in macrophages is the key stage for Yersinia pestis to finally cause disease. In the face of these complex environmental factors, Yersinia pestis must be able to sense and adapt quickly to each environmental change in order to eventually survive in the host and spread in nature and eventually cause disease. And every adaptive response must be accompanied by gene transcription changes in Yersinia pestis. Based on the stress that Yersinia pestis may face during transmission and infection, we have designed and performed transcription profiling of several simulated stimuli in vitro, including temperature (growth temperature, cold shock and heat shock), osmotic pressure (high salt), Hyperosmotic and OmpR regulators were found to be stimulating factors such as H _ 2O _ 2 and H _ 2O _ 2 stimulators and OxyR regulators, and low magnesium (low magnesium stimulators and PhoP regulators). Based on the analysis of transcriptional profiles of the whole genome DNA microarray in vitro, we obtained the characteristic transcripts of Yersinia pestis in cell metabolism and virulence under several conditions in vitro. The transcriptional analysis of wild strains and mutants obtained the genes that OmpR- OxyR and PhoP might regulate under specific conditions, which provided the target genes for the future study of regulatory networks. More importantly, we put together the transcription data of each gene in all of our lab's in vitro conditional transcripts. Summarized the transcriptional rules of virulence related genes in this study in vitro, enriched the existing research results of virulence related genes. Finally, 39 possible manipulators in Yersinia pestis genome were predicted by means of statistical analysis, which was based on the results of cluster analysis, based on the analysis of genes or gene clusters cotranscribed under many conditions in the genome of Yersinia pestis (Yersinia pestis). The functions of some genes and operons were predicted by combining genomic sequences and annotated information. These results provide some experimental evidence for the construction of gene transcriptional regulatory network and prediction of some gene functions of Yersinia pestis, which is helpful to further understand the pathogenicity of Yersinia pestis and the interaction between host and bacteria.
【学位授予单位】：中国人民解放军军事医学科学院
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R378

【引证文献】