Expression of Transgenes Targeted to the Gt(ROSA)26Sor Locus Is Orientation Dependent
Figure 4
Expression level can be increased when selectable marker is removed.
(A) Diagram of orientation of constructs in cell lines.
(B) A2B2 and A2B2Δ cells induced with doxycycline (i) A2B2 phase contrast (ii) A2B2 EGFP expression (iii) A2B2Δ phase contrast (iv) A2B2Δ EGFP expression
(C) Graph of expression levels in induced and uninduced cell lines quantitated by fluorimetry.
Expression of EGFP is higher when these cell lines have lost the selectable marker cassette (F(1,40) = 77.25, p<0.0001).
The orientation of the TRE EGFP makes no difference to expression level (F(1,40) = 1.14, p = 0.2910).
Each point is an average of three measurements each from two independently targeted cell lines.
Error bars denote standard deviations. Asterisks indicate statistically significant differences.