铁、氧代谢途径的关键基因在控制趋磁螺菌磁小体合成中的作用

项目名称： 铁、氧代谢途径的关键基因在控制趋磁螺菌磁小体合成中的作用

项目编号： No.31270093

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 李颖

作者单位： 中国农业大学

项目金额： 80万元

中文摘要： 趋磁螺菌（MSR-1）菌株的显著特征是能够从环境中吸收大量铁并在细胞内合成纳米磁小体（Fe3O4）。其必然有一套遗传和生理学机制,使细胞既可保持高铁含量又可有效避免铁的毒害。因此它是研究细胞维持铁平衡及生物矿化机制的理想材料。本研究拟采取两种控铁培养方式获得合成及不能合成磁小体的细胞，采用转录组学、荧光定量PCR等技术并配合细胞生理、生化检测手段，重点分析两种细胞在磁小体合成过程中铁、氧代谢关键基因在转录水平上的差异。 本研究拟解决的科学问题是：1.细胞中有多少个基因参与了趋磁螺菌磁小体合成？ 2. 在人为可控的条件下，趋磁螺菌与铁、氧代谢途径相关的主要基因在磁小体合成过程中是如何协调发挥作用的？该研究结果不仅可揭示铁、氧代谢关键基因在磁小体合成过程中所执行的功能及其调控特点，为人工培养提高磁小体产量提供技术参数，也可为深入探讨趋磁螺菌生物矿化机制提供理论依据和实验证据。

中文关键词： 趋磁螺菌；转录组分析；铁吸收调控蛋白；MamXY 操纵元；生物矿化

英文摘要： Magnetospirillum gryphiswaldense strain MSR-1 has the unique capability of taking up large amounts of iron and synthesizing magnetosomes (intracellular magnetic particles composed of Fe3O4), and therefore has an extremely high iron requirement.It must have precise genetic and physiological mechanisms to balance the high iron levels necessary for magnetosome production, vs. the potential toxic effects of excessive intracellular iron. The unusual high iron content of MSR-1 makes it a useful model for studying biological mechanisms of iron uptake and homeostasis. In this study, we will obtain the cells which can be synthesis and can not be synthesis magnetosomses under two iron content culture conditions. Combination of the variety of physiological, biochemical detection methods, transcriptome analysis, and especially quantitative PCR, to investigate the transcription level differences of critical genes involved iron and oxygen metabolic pathway. The project intends to solve scientific problems: 1) How many genes involved in the process of magnetosoms synthesis? 2) In artificially controlled conditions, what functions of the major genes in iron and oxygen metabolic pathways during cell growth and magnetosomes formation? The results will be reveal the differences of functions and regulational characteristics of t

英文关键词： Magnetospirillum gryphiswaldense；transcriptome analysis；ferric uptake regulator (Fur)；MamXY operon；biomineralization