Analysis of the effect of insulator sequences on SB mediated transposition in HEK293 cells and the RNAi knockdown cell line G4.

<p>(A) DNA construct used for the study. pCMV: major immediate early promoter/enhancer; polyA: poly adenylation signal of the simian virus 40; SB: Sleeping Beauty (SB) transposase; mSB: non-functional version of the SB transposase; neo: neomycin re<i>sistance cassette; HS4: chicken insulator.</i> (B) The substrate plasmid T/neo-HS4 was transfected into HEK293 or G4 cells along with either the functional Sleeping Beauty transposase (SB) or the inactive version of SB (mSB). After 2 weeks of G418 selection, cells were stained and blue colonies were counted. The ratios of transposition events (SB to mSB) in G4 cells and HEK293 cells are displayed.