The SIRT1-Tg flox-STOP-flox construct was designed to insert (from 5' to 3') an FRT site, a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG; from the pCAGGS vector), a loxP-flanked transcriptional STOP cassette, the mouse sirtuin 1 (Sirt1) cDNA sequence, and a PGK-hygro-polyA sequence (with a second FRT site between the PGK and hygro) into the 3' UTR of the mouse collagen A1 (Col1a1) locus. (J:134301)