Figure 2

Chromosomal deletion analysis system. Plasmid p3BP was linearized and integrated into the genome of 293 cells. AttB and attP sites for φC31, R4, and TP901-1 integrases are indicated. pInt-I-hrGFP is an integrase expression plasmid, in which the CMV promoter drives simultaneous expression of integrase and GFP, through the action of an IRES. Independent expression vectors were cloned for the φC31, R4, and TP901-1 integrases. HygR, hygromycin resistance; AmpR, ampicillin resistance; IRES, internal ribosome entry site; CMV, cytomegalovirus immediate early promoter; Int, Integrase gene; GFP, green fluorescent protein; polyA, poly(A) addition site from simian virus 40.