LTREB Renewal: The long-term evolution experiment with Escherichia coli

即使是一个相当小的细菌群体也可能包含数百万个细胞，每天经历几代。 因此，细菌可以快速进化并适应环境。 在这个更新项目中，研究人员将繁殖，监测，保存和研究大肠杆菌的种群，同时它们在定义的实验室环境中进化五年，使这个长期实验的持续时间超过60，000代细胞。 为了测量细菌的适应性，研究人员允许进化的细菌与它们的祖先菌株竞争。 研究人员还将这些适应性动态与基因组序列的变化进行比较，以阐明细菌进化的速率、机制和可预测性。由于细菌进化的速度和这项长期实验的精心设计，该项目提供了观察和量化进化过程的独特机会。 与此同时，细菌在几个方面极其重要：作为生态系统过程的重要参与者，作为人类和许多其他物种的疾病媒介，以及作为生物技术的主力。 因此，深入了解细菌进化的速率、机制和结果对科学和社会具有许多重要的意义和应用。这个正在进行的研究项目的科学目标和结果已经并将通过外联活动向公众展示，包括与记者的采访，非专家研讨会以及由NSF和其他媒体主办的基于网络的演示。这项研究产生的生物样本和数据集将继续与科学界分享，包括放在公共储存库的基因组序列。

Even a rather small population of bacteria may contain millions of cells that undergo several generations every day. As a result, bacteria can quickly evolve and adapt to their environments. In this renewal project, the investigators will propagate, monitor, preserve, and study populations of Escherichia coli while they evolve in a defined laboratory environment for five years, bringing the duration of this long-term experiment to over 60,000 cell generations. To measure the adaptation of the bacteria, the researchers allow the evolved bacteria to compete against their ancestral strain. The researchers also compare these adaptive dynamics with changes in genome sequences in order to elucidate the rates, mechanisms, and predictability of bacterial evolution.This project offers a unique opportunity to observe and quantify the process of evolution owing to the speed with which the bacteria evolve and the careful design of this long-term experiment. At the same time, bacteria are extremely important in several respects: as essential players in ecosystem processes, as agents of disease in humans and many other species, and as workhorses in biotechnology. Therefore, in-depth knowledge about the rates, mechanisms, and outcomes of bacterial evolution has many important implications and applications for science and society. The scientific aims and findings of this on-going research project have been and will be presented to the public via outreach activities including interviews with journalists, seminars for non-specialists, and web-based presentations hosted by the NSF and other outlets. Biological samples and datasets generated by this study will continue to be shared with the scientific community, including genome sequences placed in public repositories.