Figure 1

Integration at mouse genomic sequences. (A) Sequence from an embryo-derived PCR clone displays the characteristic site-specific crossover between the attB arm, shown in gray, and the murine pseudo attP site, mpsL1, with the TT core (in bold) located at the point of crossover. A one-base mismatch (underlined) located downstream of the crossover event may be a polymorphism between the mouse FVB/NacfBR strain and the C57Bl/6 strain that was sequenced in the database. (B) Comparison of the sequences of embryo-derived pseudo attP sites mpsL1 and mpsT1 with the wild-type φC31 attP. The common TT core is shown in bold. Both of these embryo-derived pseudo attP sites are ~30% identical to the wild-type φC31 attP. The matching base pairs with a 40 base attP are shown in gray.