Figure 4From: A versatile and highly efficient method for scarless genome editing in Escherichia coli and Salmonella entericaA gene fragment with synonymous codons maintains function of an essential gene during editing. An intact open reading frame can be reconstituted either under control of its own promoter (a) or under control of the constitutive promoter upstream of the selection marker (cat) preceding the target gene fragment (b).Back to article page