Origin activity of c-myc:Pu-Py integrants.
A, diagram of the integration site in c-myc:Pu-Py cell lines DF, DR, TF, and TR, including sequence-tagged sites (STS) used for qPCR quantitation of nascent DNA. DF and DR contain the PKD1 IVS21 88-bp mirror repeat sequence in place of the c-myc DUE; TF and TR contain the PKD1 IVS21 88-bp mirror repeat sequence in place of the c-myc triplex-forming region. R and Y refer to the orientation of the Pu-rich and Py-rich strands of the 88-bp Pu-Py repeat, respectively. B, short, nascent DNA (0.5–2.0 kb) was harvested from the indicated cell lines and quantitated by qPCR at STS-Hyg, -pBR, and -pML. WT, wild type 2.4-kb c-myc core origin; ΔDUE, DUE deleted c-myc core origin. Error bars indicate S.D.