中国生物工程杂志

With the coming of the post genome era, simple and efficient gene editing tools and methods have played a critical role in studying the regulation of gene expression and the genetic modification of engineered strains. The counter-selection methods are much convenient and efficient for gene knockout, which are based on the principle of homologous recombination. Knockout or insert of one target gene is achieved by the loss or supplement of one selective genetic marker, which generally does not rely on the traditional antibiotics. To achieve genetic manipulation of more target genes, the same selected marker can be used repeatedly over the progress of successive manipulation rounds. Because of its versatility, simplicity, efficacy, and wide range of applications, the counter-selective system has been applied in many fields of research, such as biotechnology, genetic engineering, and fundamental and applied biology. In recent years, the types, mechanisms and applications of counter-selection marker genes in microbial gene knockout experiments are reviewed. This genome-editing technique has a valuable advantage that particularly attracts the scientist’s mind, as it allows genome editing in multiple biological systems, and supports great opportunities for the future development of microbial science and rapid remodeling of genes.