Generation of SPC-Cre-ER^T2 mice.

<p>A) Schematic map of SPC-Cre-ER^T2 expression cassette. HSPC-P, human surfactant protein C promoter; Cre-ER^T2, Cre coding sequence fused with a tamoxifen-inducible estrogen receptor. pA, a polyA sequence from SV40 virus. Cre-F primer binding sites, 561–579 bp of Cre-ER^T2 transgene; Cre-R primer binding sites, 976–997 bp of Cre-ER^T2 transgene. The map is drawn in scale. B) Screening SPC-Cre-ER^T2 transgenic mice using PCR. Genomic DNA from each mouse tail was used as template to specifically PCR-amplify the Cre-ER^T2 transgene. M, DNA marker; +, SPC-Cre-ER^T2 plasmid DNA control; -, water control; F8, F13, F16, F42, F67 are five representative founder transgenic mice generated by microinjection of SPC-Cre-ER^T2 expression cassette into fertilized embryos. C) Cre-ER^T2 fusion proteins were detected using Western blot in lung tissues of SPC-Cre-ER^T2 transgenic mice. Lane 1, C57BL/6J mouse; Lane 2, an offspring of F42 founder without Cre-ER^T2 transgene when genotyped using PCR; Lane 3, 4, 5, offspring of F42 founder; Lane 6, 7, 8, offspring of F67 founder. Notice the variable expression levels of Cre-ER^T2 in offspring from the same founder.