Fig. 1

Generation of ECSF mice. a Intersectional transgenesis. The two BACs shown were co-injected into mouse eggs to generate double transgenic mice. In neurons and other cells with active Snap25 promoter, the Flpe recombinase excises the FRT-flanked Cre cassette, thus inhibiting Cre expression. Remak Schwann cells and other cells with active Egr1 promoter but inactive Snap25 promoter express Cre upon Tamoxifen treatment. b PCR genotyping of founders. Representative founders with or without the Cre and Flpe transgenes are shown. c Cre activity in ECSF mice. ECSF mice were crossed to Ai14 mice, which have a LoxP-flanked stop cassette excisable by Cre (upper). The ECSF; Ai14 progeny were injected with tamoxifen or vehicle, and tail preparations were PCRed using primers flanking the Ai14 LoxP sites. Excision of the stop cassette is evident in mice receiving tamoxifen but not vehicle (lower). ERT2, Estrogen Receptor; FRT, flippase recognition target