(A) Diagram of the 8 kb Hind III (H) genomic fragment showing the hnRNPA2B1 and CBX3 promoters and the CpG island that spans them. The Bgl II (B) site used for cloning the rtTA2S-M2SV40polyA cDNA is shown. The EcoRI (E) sites used for determining transgene copy numbers are also shown. (B) Southern blot of EcoRI digests of genomic DNA from the hnRNPA2B1-rtTA2S-M2 transgenic mouse lines to determine transgene copy numbers. Probes used: an rtTA2S-M2 fragment detecting a 4.1 kb band and, as control, a CAII probe detecting a 3.1 kb band from the endogenous carbonic anhydrase II locus. Lane 2a* shows a different exposure (n.t.: non transgenic). (C) Summary table of the transgene copy numbers for the different lines and of the chromosomal integration sites as determined by FISH (n.d.: not determined; n.centr.: near centromere; n.tel.: near telomere).