Tg(Rr141-cre)1Ksec

The 3.4 kb transgene construct contained a 1.4 kb genomic fragment containing murine Hoxb2 rhombomere 4 (r4) enhancer Rr141 inserted upstream of the beta-globin promoter to drive expression of cre cDNA with a nuclear localization signal (NLS). Five founder lines were generated. Line 5 showed mosaic expression when crossed to R26R reporter animals, while the remaining 4 recapitulated the Hoxb2-r4 expression pattern as reported previously. Lines 3 and 4 showed higher background staining while line 1 showed stronger cre activity than line 2. Line 1 was used for subsequent analyses. (J:149900)