REU: A Molecular Approach to Understanding the Genetic Response of Soil Microbial Populations Under Selection

REU：了解选择下土壤微生物种群遗传反应的分子方法

• 批准号: 8705407
• 负责人: William Holben
• 金额: $ 28.99万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-08-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8705407&HistoricalAwards=false
• 关键词: REU; Molecular; Approach; Understanding; Genetic

Drs. William E. Holben and James M. Tiedje of Michigan State University propose taking a molecular approach to understanding gene ecology and exchange under an applied selection pressure -xenobiotic chemicals in the environment. Past research in microbial ecology has provided virtually no information on genetic changes of microbial populations in soil. This omission is particularly apparent, not that the issue of release of genetically engineered microorganisms has raised questions for which little data exists to underpin interpretations of risk. To study such change, an effective and ecologically sensible selection that can be followed at the DNA level is needed. The investigators have chosen the biodegradtion of a new energy resource -- herbicides -- as the system of study. They proposed to test the hypothesis that the native and soil microbial population is not genetically optimized for use of a new energy resource when first introduced, but that after repeated exposure, genetic changes will be selected that enhance the ability of populations to use these chemicals. By using gene-specific probes, DNA restriction analysis, hybridization and related molecular methods, they can distinguish among the five most likely genetic responses: (i) regulatory changes resulting in altered gene expression; (ii) a mutation which results in a new metabolic activity; (iii) rearrangement or amplification of genetic information; (iv) transfer of genetic information to similar organisms; (v) transfer of genetic information to dissimilatory organisms. While there is little doubt that these types of genetic changes that occur in the laboratory, there is little information on which are to prevalent changes that occur in nature, at what frequency and under what conditions. To provide this information, they propose to study these changes using chemostats, soil microcosms, field studies and a retrospective analysis of populations after 20 years of agrochemical treatment. This continuum of approaches should allow them to extrapolate information on mechanism and frequency between laboratory and field. Information on the latter is entirely lacking. This is extremely timely and much needed research by several groups in the scientific community (e.g., regulatory agencies) as well as by an industry struggling to make "safe" new organisms and their products by genetic manipulation. The investigators and their organization are world renowened for their expertise in this field.

Drs. William E. Holben和James M.蒂耶 州立大学建议采用分子方法， 理解基因生态学和交换下的应用 选择压力-环境中的异生化学物质。 过去的微生物生态学研究几乎提供了 没有关于微生物种群遗传变化的信息 土壤 这一遗漏特别明显，并不是说 基因工程微生物释放问题 提出了一些几乎没有数据支持的问题， 风险的解释。 为了研究这种变化，有效的 和生态上合理的选择， 需要DNA水平。 研究人员选择了一种新的 能源--除草剂--作为研究的系统。 他们 提出来检验本土和土壤的假设 微生物种群不是遗传优化的， 当新能源首次引入时， 重复暴露，遗传变化将被选择， 提高人们使用这些化学品的能力。 通过 使用基因特异性探针，DNA限制性分析， 杂交和相关的分子方法，它们可以 区分五种最可能的遗传反应：（i） 导致基因表达改变的调控变化;（ii）a 导致新的代谢活性的突变;（iii） 基因信息的重排或扩增;（iv） 将遗传信息转移给类似的生物体; ㈤ 将遗传信息传递给异化生物。 虽然毫无疑问，这些类型的基因变化 在实验室里发生的，几乎没有关于 在自然界中发生的普遍变化， 频率和条件。提供这种 信息，他们建议使用 恒化器，土壤微观世界，实地研究和回顾 农药施用20年后的种群分析 治疗 这一连续的方法应使他们能够 推断机制和频率之间的信息 实验室和现场。 关于后者的信息完全是 缺乏 这是非常及时和急需的研究， 科学界的几个团体（例如，监管 代理商）以及努力使“安全” 新的生物体及其产品通过基因操作。 调查人员及其组织是世界 他们在这一领域的专业知识而闻名。