Fig. 4.
Genetic constructs used for the generation of the mouse model for temporally and spatially controlled expression of TeNTΔ1-GFP. (A) Schematic representation of the 3×TG (triple transgenic) mouse genotype: GFAP-tTA; GFAP-Cre-ERt2; TRE-STOP-TeNT-GFP. (B) TeNT is expressed only when the STOP sequence is removed following tamoxifen administration, which activates the Cre-ER protein required to excise the STOP sequence by loxP sequences. (C) The tTA is inactivated by doxycycline, resulting in the complete suppression of TeNT expression. Therefore, in the triple transgenic mouse, TeNT toxin expression is induced by tamoxifen injection and suppressed by feeding doxycycline.