Figure 2. Reversible Tethering of GFP-LacI to the ψVλ Array in DT40 PolyLacO-λ_R .

(A) Schematic diagram of the rearranged chicken Igλ locus in DT40, with PolyLacO inserted between ψVλ17 and ψVλ20. Notations as in Figure 1.

(B) Fluorescent images of DT40 GFP-LacI transfectants and DT40 PolyLacO-Vλ_R GFP-LacI transfectants cultured in the absence of IPTG (center) or in the presence of 100 μM IPTG overnight (right).