Tg(Pdx1-itTA)#Fto

Mice bearing this transgene express the tetracycline transactivator under the control of of the promoter sequences of the mouse pancreatic and duodenal homeobox 1 (Pdx1) gene. The transgene was generated from the C57BL/6J-derived mouse bacterial artificial chromosome (BAC) clone RP24-367D23, which contains the Pdx1 coding region, 78 kb of genomic DNA upstream of its start codon, and, downstream of its polyadenylation signal, 118 kb of DNA including the Cdx2 and Flt3 genes. Cdx2 and Flt3 were inactivated by deletion of DNA segments including their respective start codons. The Pdx1 gene was modified by replacement of most of exon 1 from the initiating ATG with the improved codon tetracycline transactivator (itTA) coding sequence followed by a polyadenylation signal, inactivating Pdx1. X-gal staining of tissue sections from mice carrying this and a lacZ reporter transgene under control of the tetracycline responsive element reveals beta-galactosidase expression from embryonic day (E) 11.5 in all pancreatic precursor cells and, in the adult, in beta, delta and sparse acinar cells of the pancreas, as well as a few cells in the stomach, duodenum and kidney. (J:223993)