| Primary Identifier | MGI:5810641 | Allele Type | Transgenic |
| Attribute String | Transactivator | Gene | Tg(Ins1-itTA)#Fto |
| Strain of Origin | Not Specified | Is Recombinase | false |
| Is Wild Type | false |
| description | This transgene in combination with a second transgene whose expression is regulated by the tetracycline responsive element, comprising 7 copies of the tetracycline operator sequence (tetO) separated by spacer DNA sequences, functions as a Tet-Off system: When bound to doxycycline, the tTA protein represses transcription of the tetO-controlled target sequence. |
| molecularNote | MIce bearing this transgene express the improved-codon tetracycline transactivator (itTA) coding sequence under control of the promoter sequences of the mouse insulin 1 (Ins1) gene. The transgene was generated from the C57BL/6J-derived mouse bacterial artificial chromosome (BAC) clone RP23-401C13, containing the insulin 1 (Ins1) coding region and 110 kb and 87 kb of genomic DNA sequence upstream of its start codon and downstream of its polyadenylation signal, respectively. A cassette containing the itTA coding sequence followed by a single FRT site has replaced a 317-bp DNA segment beginning 3 bp upstream of the translation-initiating ATG of Ins1, disrupting the Ins1 open reading frame. X-gal staining of organ sections of mice carrying this and a second transgene expressing the E. coli lacZ gene under control of the tetracycline operator (tetO), in the absence of doxycycline, reveals beta-galactosidase expression that is restricted at embryonic day (E) 13.5 to the pancreatic buds, at E15 to the entire pancreas, and in the adult to insulin-expressing beta cells of the pancreatic islets. |
