[Recent advances of continuous in vivo evolution]

Laboratory evolution is an important approach to improve the performance of microorganisms. In the past decades, the methods for laboratory evolution have developed rapidly and applied widely. However, the commonly used evolution strategies for strains or specific proteins cannot achieve continuous mutation, and require multiple rounds of operation, therefore they are considered as a labor intensive process. The development of mutation and screening technologies have facilitated the development of continuous evolution in vivo and greatly improved the efficiency of laboratory evolution. The continuous in vivo evolution achieves in vivo mutation, perfectly combining mutation with screening to evolve a specific phenotype with minimal human intervention. This review summarizes the recent advances of in vivo continuous evolution technologies for either genome-scale mutation or evolution of specific proteins. The principles of these technologies and their applications are introduced. On this basis, the advantages and limitations of these technologies are discussed. We also give a perspective of future development of continuous in vivo evolution.