Fig. 1From: Construction of an easy-to-use CRISPR-Cas9 system by patching a newly designed EXIT circuitConceptual illustration of the EXIT circuit. The EXIT circuit comprises a control module and an exit module. The two modules can be assembled into one or more plasmids. Activation of the homing endonuclease gene (HEG) will result in cleavage of the control and exit modules, thereby eliminating the host plasmidsBack to article page